Dissertations / Theses on the topic 'Control of steering systems'
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Dell’Amico, Alessandro. "Pressure Control in Hydraulic Power Steering Systems." Licentiate thesis, Linköpings universitet, Fluida och mekatroniska system, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-100841.
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There is a clear trend in the vehicle industry to implement more safetyrelated functions, where the focus is on active safety systems and today the steering system is also involved. Steering-related active safety functions can only be realised with a steering system that allows electroniccontrol of either the road wheel angle or the torque required to steer the vehicle, called active steering. The high power requirement of heavy vehicles means they must rely on hydraulic power to assist the driver. Thesystem is a pure hydro-mechanical system with an open-centre circuit activated by the driver’s steering action and suffers from poor energy efficiency. The main task of the hydraulic system is to control the pressure in the assistance cylinder in such a way that it eases the load on the driver. This work suggests a way to design and evaluate a self-regulating pressure control valve for use as actuator in the steering system. This valve can be made small and fast and is electronically controlled to enable active steering. It is based on a closed-centre circuit and has therefore the potential to improve energy efficiency. The aim of this work has been to investigate the possibility for the valve to perform as the original open-centre valve. The suggested approach is a model-based design and evaluation process where an optimisation routine is used to design the valve. Together with a validated model of the steering system, the new concept is compared with the original system. A hardware-inthe-loop simulation test rig has also been designed and built with the possibility to test a closed-centre steering system. It has partly been used to support the modelling process and partly to verify that a closedcentre steering system is a feasible solution. The simulation results have shown that the designed valve can perform sufficiently well compared to the original system.
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Yamamoto, Kazusa. "Control of electromechanical systems, application on electric power steering systems." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT069/document.
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De nos jours, la plupart des véhicules sont équipés de Directions Assistées Electriques (DAE). Ce type de systèmes d'aide à la conduite permet de réduire les efforts que le conducteur doit fournir pour tourner les roues. Ainsi, grâce à un moteur électrique, la DAE applique un couple additionnel en accord avec le comportement du conducteur et la dynamique du véhicule. Il est donc nécessaire de développer une commande en couple basée en particulier sur le signal provenant d'un capteur mesurant le couple agissant au niveau de la barre de torsion (correspondant à une image du couple conducteur). Ce composant est donc essentiel au fonctionnement de la DAE. Or, une défaillance de ce capteur entraine le plus souvent une coupure de l'assistance, pouvant mener à un risque d'accidents. Au regard de la sécurité fonctionnelle, un développement d'un mode de sécurité est recommandé, par de plus en plus de constructeurs automobiles. D'autre part, le marché des équipementiers automobiles reste un secteur très concurrentiel où une baisse des coûts de production est un challenge constamment recherché afin de gagner de nouvelles parts de marchés. Cet aspect de réduction du nombre de capteurs et d'analyse de la dynamique du véhicule s'inscrit donc dans le prolongement de la stratégie de sécurité. Cette thèse, menée au sein de JTEKT Europe, aborde ces divers enjeux. Après une présentation des différents systèmes de directions assistés électriques, des modèles sont présentés pour être utilisés lors de la conception de lois de commande et d'estimateurs. Ensuite deux méthodes d'estimation du couple conducteur sujet aux perturbations de la route et aux bruits de mesures sont proposées : la première est un observateur proportionnel intégral (PI) à synthèse mixte $H_infty/H_2$, et la seconde une approche par filtrage $H_infty$. Puis plusieurs stratégies de commande sont proposées suivant deux cas de figures distincts, soit en utilisant un observateur PI qui estime les états du système et le couple conducteur (LQR, commande LPV par retour d'état), soit en faisant abstraction d'estimateur de couple conducteur (commande $H_infty$ par retour de sortie dynamique). Ce dernier aspect présente l'avantage de nécessiter moins de mesures que le précédent. Ces approches ont été validées en simulation et mises en œuvre sur un véhicule prototype où des résultats prometteurs ont été obtenusNowadays, modern vehicles are equipped with more and more driving assistance systems, among them Electric Power Steering (EPS) helps the driver to turn the wheels. Indeed, EPS provides through an electric motor, an additional torque according to the driver's behaviour and the vehicle's dynamics to reduce the amount of effort required to the driver. Therefore, a torque control is developed based on the torque sensor signal which measures in practice the torsion bar torque (corresponding to an image of the driver torque). Consequently, this component is essential to the functioning of EPS systems.Indeed, a torque sensor failure usually leads to shut-off the assistance which may increase the risk of accident. Regarding functional safety, a back-up mode is recommended and required by more and more car manufacturers. On the other hand, a major challenge for automotive suppliers is to reduce cost production in order to meet growing markets demands and manage in the competitive sector. This issue considering a reduction of sensors' numbers and analysis of vehicle's dynamics is therefore an extension of applying the safety strategy. This thesis, carried out within JTEKT Europe, addresses these various issues.After introducing an overview of the different EPS systems, some models used for the design of controllers and estimators are presented. Then, two methods to estimate the driver torque subject to road disturbances and noise measurements are proposed: the first is a proportional integral observer (PI) with mixed synthesis $H_infty / H_2 $, whereas the second is an $ H_infty $ filtering approach. Then, several control strategies are proposed according to two different cases, either by using a PI observer which estimates the system states and the driver torque (LQR, LPV feedback control) or by not taking into account the driver torque estimation ($ H_infty $dynamic output feedback control). This latter approach has the advantage to require less measurements than the previous one. These approaches have been validated in simulation and implemented on a prototype vehicle where promising results have been obtained
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Asghar, Sajjad. "Exact steering in control of moment gyroscope systems." Thesis, University of Surrey, 2008. http://epubs.surrey.ac.uk/770151/.
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Single Gimbal Control Moment Gyroscopes (CMGs) are thought to be efficient actuators for the attitude control of the new generation of small and agile satellites. CMGs belong to a class of actuators known as momentum exchange devices. This thesis presents a detailed formulation of three-axis attitude dynamics and control of a satellite equipped with a cluster of n momentum exchange devices (which include CMGs and reaction wheels).
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Yavuzoglu, Emre. "Steering Laws For Control Moment Gyroscope Systems Used In Spacecraft Attitude Control." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1098441/index.pdf.
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In this thesis, the kinematic properties of Single Gimballed Control Moment Gyroscopes (SGCMGs) are investigated. Singularity phenomenon inherent to them is explained. Furthermore, existing steering laws with their derivations are given.
A novel steering law is developed that may provide singularity avoidance or may be used for quick transition through a singularity with small torque errors. To avoid singularity angular momentum trajectory of the maneuver is to be simulated in advance for the calculation of singularity free gimbal histories. The steering law, besides accurately generating required torques, also pushes the system to follow trajectories closely if there is a small difference between the planned and the realized momentum histories. Thus, it may be used in a feedback system. Also presented are number of approaches for singularity avoidance or quick transition through a singularity. The application of these ideas to the feedback controlled spacecraft is also presented. Existing steering laws and the proposed method are compared through computer simulations. It is shown that the proposed steering law is very effective in singularity avoidance and quick transition through singularities. Furthermore, the approach is demonstrated to be repeatable even singularity is encountered.
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Ouyang, Xiaohong. "Neural network identification and control of electrical power steering systems." Thesis, University of Wolverhampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323099.
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Bedrossian, Nazareth Sarkis. "Steering law design for redundant single gimbal Control Movement Gyro systems." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14663.
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Diab, Ali. "Stability analysis and control design for time-delay systems with applications to automotive steering systems." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPAST057.
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L'assistance de direction aide le conducteur à manoeuvrer son véhicule en diminuant le couple exercé sur le volant. Dans le cas de la « direction assistée électrique » et du « steer-by-wire », le système d'assistance est composé de moteurs électriques placés au niveau de la crémaillère (pour déplacer les roues) et au niveau du volant (pour fournir au conducteur un retour des forces agissant sur les roues). Cependant, ces architectures introduisent des retards dans les boucles de rétroaction du système. Pour assurer la stabilité en présence de retards, on peut réduire le gain d'assistance ou augmenter l'amortissement du volant, mais cela a un impact négatif sur les performances du système et détériore le retour d'effort renvoyé au conducteur. Afin de surmonter cette limitation, nous concevons et analysons des lois de commande pour les systèmes de direction qui augmentent (par rapport aux stratégies actuelles) la marge de retard du système. Nous utilisons une approche fréquentielle pour analyser les contraintes imposées par la stabilité du système de rétroaction générant le couple volant. Nos algorithmes s'appuient sur des architectures de commande proportionnelles-dérivées classiques, comprenant des lois d'assistance et des filtres. La simplicité des méthodes proposées permet un calcul analytique de la marge de retard. De plus, pour rendre nos résultats plus généraux (par exemple, pour des lois d'assistance non linéaires), nous développons des techniques dans le domaine temporel pour analyser la stabilité des systèmes linéaires à retards en utilisant des fonctionnelles de Lyapunov-Krasovskii. Nous formulons une méthode basée sur des projections permettant à des ensembles généraux de fonctions de paramétrer les fonctionnelles de Lyapunov-Krasovskii. Nous discutons des principales hypothèses considérées dans notre formulation et établissons des connexions entre les approches existantes pour l'analyse de la stabilité des systèmes à retard basées sur la programmation semi-définie, à savoir la méthode basée sur l'utilisation d'inégalités intégrales et la méthode basée sur la programmation par somme de carrés. Enfin, les résultats obtenus sont également appliqués au cas test des systèmes de directionSteering assistance helps the driver to maneuver the vehicle by reducing the steering effort. In the case of electric power steering and steer-by-wire, the assistance system is composed of electrical drives placed at the rack pinion (allowing the wheels to move) and at the steering wheel (providing the driver a feeling of the forces acting on the wheels). These architectures introduce, however, delays in the feedback loops of the system. To ensure its stability in the presence of delays, one can reduce the assist gain or increase the damping of the steering wheel, but this negatively impacts the system's performance and degrades the force feedback returned to the driver. In order to counter this limitation, we design and analyze control laws for steering systems that increase (compared to current strategies) the delay margin of the system. We use a frequency-domain approach to analyze the constraints imposed by the stability of the feedback system generating the steering wheel torque. Our algorithms rely on classical proportional-derivative control architectures, including torque maps and filters. The simplicity of the proposed methods allows an analytical computation of the delay margin. In addition, to make our results more general (for example, for nonlinear torque maps), we develop time-domain techniques to analyze the stability of linear time-delay systems using Lyapunov-Krasovskii functionals. We formulate a projection-based method allowing general sets of functions to parameterize Lyapunov-Krasovskii functionals. We discuss the main assumptions considered in our formulation and establish connections between the existing approaches for the stability analysis of time-delay systems based on semidefinite programming, namely the method based on the use of integral inequalities and the method based on sum-of-squares programming. Finally, the obtained results are also applied to the test case of steering systems
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Bansal, Mayur. "DIGITAL CONTROL BOARD FOR PHASED ARRAY ANTENNA BEAM STEERING IN ADAPTIVE COMMUNICATION APPLICATIONS." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1113.
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The application of adaptive communication techniques for mobile communications has attracted considerable interest in the last decade. One example of these techniques is spatial filtering through planar antenna array beam forming.
This thesis describes the development of a digital system that adaptively controls a phased array antenna. The radiating structure of the phased antenna array is tetrahedral-shaped and contains four antenna elements on each of its three faces. The overall system comprises of a digital control board with an external computer interface, an RF control board, and the phased antenna array. The RF controls the main lobe direction on the phased array antenna. This thesis describes the design and implementation of the digital control board.
The digital control board`s primary responsibilities are implementing inter- faces between the external computer and the RF board, which results in two operational modes: the MATLAB graphical user interface (GUI) mode and the adaptive receive mode. The GUI mode allows users to input parameters that provide interactive control of the phased antenna array by interfacing with an external computer and the RF control board. The adaptive receive mode im- plements an algorithm for an adaptive receive station. This algorithm uses a 58-point scanning technique that locates the maximum receive power direction.
Test results show that the digital control board successfully manages the RF board control voltage with an nominal error of less than 1%, which subsequently allows for precise control of the antenna`s active face. Additionally, testing of the GUI demonstrated the successful interactive application of various system control parameters.
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Avak, Bjoern. "Modeling and Control of a Superimposed Steering System." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5039.
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A superimposed steering system is the combination of a conventional steering system with an electric motor which is used to alter the steering angle imposed by the driver. The potential benefits are increased agility, automatic compensation for lateral wind forces and decreased braking distance (in combination with an electronic stability program). In this thesis we implement a model and a controller for a superimposed steering system thus achieving the first of these potential benefits.
The vehicle model is based on the single-track or bicycle model. Unlike most other publications, the motor model in this thesis goes down to the level of the electrical dynamics of the motor. The model is divided into three main modules (vehicle module, steering module and friction module) as well as several submodules to ensure easy adaptability.
The overall control objective consists of increasing vehicle agility by achieving a variable ratio between the steering wheel angle and the actual road wheel angle as a function vehicle velocity. We divide the controller into a torque and a current controller. The actual controller is derived in three steps starting from an analog torque controller as well as an analog current controller then moving to a digital torque controller. In doing so we use the model matching, feedback linearization and state feedback control techniques.
The model and the controller are evaluated using the parameters of a small truck and different road scenarios. Finally, the Validation Square technique is applied to assess the validity of the results.
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Bakolas, Efstathios. "Optimal steering for kinematic vehicles with applications to spatially distributed agents." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42873.
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The recent technological advances in the field of autonomous vehicles have resulted in a growing impetus for researchers to improve the current framework of mission planning and execution within both the military and civilian contexts. Many recent efforts towards this direction emphasize the importance of replacing the so-called monolithic paradigm, where a mission is planned, monitored, and controlled by a unique global decision maker, with a network centric paradigm, where the same mission related tasks are performed by networks of interacting decision makers (autonomous vehicles). The interest in applications involving teams of autonomous vehicles is expected to significantly grow in the near future as new paradigms for their use are constantly being proposed for a diverse spectrum of real world applications.
One promising approach to extend available techniques for addressing problems involving a single autonomous vehicle to those involving teams of autonomous vehicles is to use the concept of Voronoi diagram as a means for reducing the complexity of the multi-vehicle problem. In particular, the Voronoi diagram provides a spatial partition of the environment the team of vehicles operate in, where each element of this partition is associated with a unique vehicle from the team. The partition induces, in turn, a graph abstraction of the operating space that is in a one-to-one correspondence with the network abstraction of the team of autonomous vehicles; a fact that can provide both conceptual and analytical advantages during mission planning and execution. In this dissertation, we propose the use of a new class of Voronoi-like partitioning schemes with respect to state-dependent proximity (pseudo-) metrics rather than the Euclidean distance or other generalized distance functions, which are typically used in the literature. An important nuance here is that, in contrast to the Euclidean distance, state-dependent metrics can succinctly capture system theoretic features of each vehicle from the team (e.g., vehicle kinematics), as well as the environment-vehicle interactions, which are induced, for example, by local winds/currents. We subsequently illustrate how the proposed concept of state-dependent Voronoi-like partition can induce local control schemes for problems involving networks of spatially distributed autonomous vehicles by examining different application scenarios.
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Shoemaker, Adam Kenneth. "Nonholonomic Control Utilizing Kinematic Constraints of Differential and Ackermann Steering Based Platforms." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78053.
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A nonholonomic tracking controller is designed and adapted to work with both differential steering and Ackermann steering based platforms whose dynamics are represented using a unicycle model. The goal of this work is to find a relatively simple approach that offers a practical alternative to bulky and expensive algorithms, but still bolsters applicability where many other lightweight algorithms are too lax. The hope is that this alternative will offer a straightforward approach for groups interested in autonomous vehicle research but who do not have the resources or personnel to implement more complex solutions. In the first phase of this work, saturation constraints based on differential drive kinematics are added to ensure that the vehicle behaves intuitively and does not exceed user defined limitations. A new strategy for mapping commands back into a viable envelope is introduced, and the restrictions are accounted for using Lyapunov stability criteria. This stage of work is validated through simulation and experimentation. Following the development of differential drive methods, similar techniques are applied to Ackermann steering kinematic constraints. An additional saturation algorithm is presented, which likewise is accounted for using Lyapunov stability criteria. As with the differential case, the Ackermann design is validated through simulation and experimentation. Overall, the results presented in this work demonstrate that the developed algorithms show significant promise and offer a lightweight, practical solution to the problem of vehicle tracking control.Master of Science
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Kandula, Prasanth Babu. "Dynamics anc Control of an Electric Power Assist Steering System." Cleveland State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=csu1282840488.
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Borretti, Biagio, Nicola Musciagna, Luca Riccò, and Andrea Fornaciari. "Intelligent twin steering system." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71114.
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This article describes the Dana intelligent Twin Steering System designed for mobile vehicles with two steering axles (i.e. with four steering wheels). Current vehicles with four-wheel steering function are typically equipped with a hydraulic configuration where the two steering cylinders are connected in series. This type of connection highlights some limitations on available power, steering comfort and enabling advanced working functions. Dana evolved this type of hydraulic configuration introducing the possibility to disconnect the rear axle from the front one. In this way the rear axle, through the electronic control of its valve block, allows to improve the steering system performance and introduces advanced steering functions compared to the conventional steering systems.
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Richter, Ralph. "A predictive fuzzy-neural autopilot for the guidance of small motorised marine craft." Thesis, University of Plymouth, 2000. http://hdl.handle.net/10026.1/2665.
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This thesis investigates the design and evaluation of a control system, that is able to adapt quickly to changes in environment and steering characteristics. This type of controller is particularly suited for applications with wide-ranging working conditions such as those experienced by small motorised craft. A small motorised craft is assumed to be highly agile and prone to disturbances, being thrown off-course very easily when travelling at high speed 'but rather heavy and sluggish at low speeds. Unlike large vessels, the steering characteristics of the craft will change tremendously with a change in forward speed. Any new design of autopilot needs to be to compensate for these changes in dynamic characteristics to maintain near optimal levels of performance. This study identities the problems that need to be overcome and the variables involved. A self-organising fuzzy logic controller is developed and tested in simulation. This type of controller learns on-line but has certain performance limitations. The major original contribution of this research investigation is the development of an improved self-adaptive and predictive control concept, the Predictive Self-organising Fuzzy Logic Controller (PSoFLC). The novel feature of the control algorithm is that is uses a neural network as a predictive simulator of the boat's future response and this network is then incorporated into the control loop to improve the course changing, as well as course keeping capabilities of the autopilot investigated. The autopilot is tested in simulation to validate the working principle of the concept and to demonstrate the self-tuning of the control parameters. Further work is required to establish the suitability of the proposed novel concept to other control.
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Soltani, Amirmasoud. "Low cost integration of Electric Power-Assisted Steering (EPAS) with Enhanced Stability Program (ESP)." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/8829.
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Vehicle Dynamics Control (VDC) systems (also known as Active Chassis systems) are mechatronic systems developed for improving vehicle comfort, handling and/or stability. Traditionally, most of these systems have been individually developed and manufactured by various suppliers and utilised by automotive manufacturers. These decentralised control systems usually improve one aspect of vehicle performance and in some cases even worsen some other features of the vehicle. Although the benefit of the stand-alone VDC systems has been proven, however, by increasing the number of the active systems in vehicles, the importance of controlling them in a coordinated and integrated manner to reduce the system complexity, eliminate the possible conflicts as well as expand the system operational envelope, has become predominant. The subject of Integrated Vehicle Dynamics Control (IVDC) for improving the overall vehicle performance in the existence of several VDC active systems has recently become the topic of many research and development activities in both academia and industries Several approaches have been proposed for integration of vehicle control systems, which range from the simple and obvious solution of networking the sensors, actuators and processors signals through different protocols like CAN or FlexRay, to some sort of complicated multi-layered, multi-variable control architectures. In fact, development of an integrated control system is a challenging multidisciplinary task and should be able to reduce the complexity, increase the flexibility and improve the overall performance of the vehicle. The aim of this thesis is to develop a low-cost control scheme for integration of Electric Power-Assisted Steering (EPAS) system with Enhanced Stability Program (ESP) system to improve driver comfort as well as vehicle safety. In this dissertation, a systematic approach toward a modular, flexible and reconfigurable control architecture for integrated vehicle dynamics control systems is proposed which can be implemented in real time environment with low computational cost. The proposed control architecture, so named “Integrated Vehicle Control System (IVCS)”, is customised for integration of EPAS and ESP control systems. IVCS architecture consists of three cascade control loops, including high-level vehicle control, low-level (steering torque and brake slip) control and smart actuator (EPAS and EHB) control systems. The controllers are designed based on Youla parameterisation (closed-loop shaping) method. A fast, adaptive and reconfigurable control allocation scheme is proposed to coordinate the control of EPAS and ESP systems. An integrated ESP & ESP HiL/RCP system including the real EPAS and Electro Hydraulic Brake (EHB) smart actuators integrated with a virtual vehicle model (using CarMaker/HiL®) with driver in the loop capability is designed and utilised as a rapid control development platform to verify and validate the developed control systems in real time environment. Integrated Vehicle Dynamic Control is one of the most promising and challenging research and development topics. A general architecture and control logic of the IVDC system based on a modular and reconfigurable control allocation scheme for redundant systems is presented in this research. The proposed fault tolerant configuration is applicable for not only integrated control of EPAS and ESP system but also for integration of other types of the vehicle active systems which could be the subject of future works.
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Kruger, Iwan Carel. "An aircraft based emulation platform and control model for LEO satellite antenna beam steering." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5200.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: A joint project between the KU Leuven and Stellenbosch Universities was at the time of this thesis underway to develop a space borne electronically beam steerable antenna and the associated ground-space segments. This thesis covers the development of an aircraft based satellite emulator to facilitate convenient aircraft based testing of an antenna array, intended for low earth orbit satellite deployment and subsystems to control the antenna array. A flight strategy is developed to emulate such a satellite pass as best possible, with the strategy implemented in software on in-flight PC hardware. A full interface between the aircraft avionics and satellite bus system has been developed to enable generation of the required antenna steering commands and to create a satellite bus image to the payload. Successful test results are presented, as obtained from the actual aircraft ight simulator. The thesis describes the successful development and testing of a low altitude flight test strategy for certain satellite borne systems, as a cost-effective and realistic interim step to actual and very expensive space flight testing.
AFRIKAANSE OPSOMMING: 'n Gesamentlike projek deur KU Leuven en Stellenbosch Universiteit was tydens die verloop van hierdie tesis besig met die ontwikkeling om 'n ruimte gebaseerde elektroniese straal beheerde antenna en geassosieerde substelsels daar te stel. Hierdie tesis handel oor die ontwikkeling van 'n vliegtuig gebaseerde satelliet emulator om die toetsing van 'n elektroniese stuurbare antenna, wat bedoel is vir 'n lae aardse wentelbaan, te fasiliteer en die ontwikkeling van substelsels wat die stuurbare antenna beheer. 'n Vlug strategie is ontwikkel om so 'n satelliet wentelbaan so na as moontlik te emuleer. Die strategie word dan geïmplementeer in die sagteware van die aanboord vlug rekenaar. 'n Intervlak tussen die vliegtuig instrumente en satellietbus is ontwikkel om die generering van die nodinge instruksies te fasiliteer en om 'n virtuele satellietbus vir die res van die satelliet stelsel te skep. Suksesvolle toets resultate word getoon wat met behulp van 'n vliegtuig simulator verkry is. Die tesis beskryf die suksesvolle ontwikkeling en toetsing van 'n lae vlugtoets strategie vir satelliet stelsels, as 'n koste effektiewe en realistiese tussenstap, tot baie duur ruimte vlugtoetsing.
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Gartley, Evan Robert Bevly David M. "On-line estimation of implement dynamics for adaptive steering control of farm tractors." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Thesis/GARTLEY_EVAN_39.pdf.
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Dong, Zhilin. "The development of electrohydraulic steering control system for off-road vehicle automatic guidance." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5981.
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Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 9, 2007) Vita. Includes bibliographical references.
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TOTA, ANTONIO. "Integration of Active Systems for a Global Chassis Control Design." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2675382.
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Vehicle chassis control active systems (braking, suspension, steering and driveline), from the first ABS/ESC control unit to the current advanced driver assistance systems (ADAS), are progressively revolutionizing the way of thinking and designing the vehicle, improving its interaction with the surrounding world (V2V and V2X) and have led to excellent results in terms of safety and performances (dynamic behavior and drivability). They are usually referred as intelligent vehicles due to a software/hardware architecture able to assist the driver for achieving specific safety margin and/or optimal vehicle dynamic behavior. Moreover, industrial and academic communities agree that these technologies will progress till the diffusion of the so called autonomous cars which are able to drive robustly in a wide range of traffic scenarios. Different autonomous vehicles are already available in Europe, Japan and United States and several solutions have been proposed for smart cities and/or small public area like university campus. In this context, the present research activity aims at improving safety, comfort and performances through the integration of global active chassis control: the purposes are to study, design and implement control strategies to support the driver for achieving one or more final target among safety, comfort and performance. Specifically, the vehicle subsystems that are involved in the present research for active systems development are the steering system, the propulsion system, the transmission and the braking system. The thesis is divided into three sections related to different applications of active systems that, starting from a robust theoretical design procedure, are strongly supported by objective experimental results obtained fromHardware In the Loop (HIL) test rigs and/or proving ground testing sessions. The first chapter is dedicated to one of the most discussed topic about autonomous driving due to its impact from the social point of view and in terms of human error mitigation when the driver is not prompt enough. In particular, it is here analyzed the automated steering control which is already implemented for automatic parking and that could represent also a key element for conventional passenger car in emergency situation where a braking intervention is not enough for avoiding an imminent collision. The activity is focused on different steering controllers design and their implementation for an autonomous vehicle; an obstacle collision avoidance adaptation is introduced for future implementations. Three different controllers, Proportional Derivative (PD), PD+Feedforward (FF) e PD+Integral Sliding Mode (ISM), are designed for tracking a reference trajectory that can be modified in real-time for obstacle avoidance purposes. Furthermore, PD+FF and PD+ISM logic are able to improve the tracking performances of automated steering during cornering maneuvers, relevant fromthe collision avoidance point of view. Path tracking control and its obstacle avoidance enhancement is also shown during experimental tests executed in a proving ground through its implementation for an autonomous vehicle demonstrator. Even if the activity is presented for an autonomous vehicle, the active control can be developed also for a conventional vehicle equipped with an Electronic Power Steering (EPS) or Steer-by-wire architectures. The second chapter describes a Torque Vectoring (TV) control strategy, applied to a Fully Electric Vehicle (FEV) with four independent electric motor (one for each wheel), that aims to optimize the lateral vehicle behavior by a proper electric motor torque regulation. A yaw rate controller is presented and designed in order to achieve a desired steady-state lateral behaviour of the car (handling task). Furthermore, a sideslip angle controller is also integrated to preserve vehicle stability during emergency situations (safety task). LQR, LQR+FF and ISM strategies are formulated and explained for yaw rate and concurrent yaw rate/sideslip angle control techniques also comparing their advantages and weakness points. The TV strategy is implemented and calibrated on a FEV demonstrator by executing experimental maneuvers (step steer, skid pad, lane change and sequence of step steers) thus proving the efficacy of the proposed controller and the safety contribution guaranteed by the sideslip control. The TV could be also applied for internal combustion engine driven vehicles by installing specific torque vectoring differentials, able to distribute the torque generated by the engine to each wheel independently. The TV strategy evaluated in the second chapter can be influenced by the presence of a transmission between themotor (or the engine) and wheels (where the torque control is supposed to be designed): in addition to the mechanical delay introduced by transmission components, the presence of gears backlashes can provoke undesired noises and vibrations in presence of torque sign inversion. The last chapter is thus related to a new method for noises and vibration attenuation for a Dual Clutch Transmission (DCT). This is achieved in a new way by integrating the powertrain control with the braking system control, which are historically and conventionally analyzed and designed separately. It is showed that a torsional preload effect can be obtained on transmission components by increasing the wheel torque and concurrently applying a braking wheel torque. For this reason, a pressure following controller is presented and validated through a Hardware In the Loop (HIL) test rig in order to track a reference value of braking torque thus ensuring the desired preload effect and noises reduction. Experimental results demonstrates the efficacy of the controller, also opening new scenario for global chassis control design. Finally, some general conclusions are drawn and possible future activities and recommendations are proposed for further investigations or improvements with respect to the results shown in the present work.
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Angelov, Ilcho, and Alexander Mitov. "Test Bench for Experimental Research and Identification of Electrohydraulic Steering Units." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200507.
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The paper presents design solution and physical implementation of a system for examination of electro hydraulic steering based on OSPE 200 components. The implementation is based on synthesis of required hydraulic and structure parameters, presented in a previous paper. Now we present the interconnection of the digital control system and the closed-loop flow diagram. A formal description of embedded software is presented too, which supports operation of PI control algorithm in real-time. Identification is performed based on experimentally reported the transitional process by developing mathematical models. Presents the structure and capabilities of the models for identification, as well as procedures for their validation.
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Törnroth, Oscar, and Truls Nyberg. "Design and Implementation of a Strategy for Path Tracking on Autonomous Heavy-Duty Vehicles." Thesis, Linköpings universitet, Fordonssystem, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149266.
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In this thesis, a combined feedforward and feedback controller for improved path tracking on autonomous heavy-duty vehicles is designed and implemented. The steering wheel is controlled in order to follow a reference curvature, computed by a higher-level MPC, responsible for minimizing the distance to a planned path. The steering dynamics, from steering wheel via wheel angles, to a measurable vehicle curvature, is modeled, and a conversion from desired curvature gain to input angle to the steering wheel is derived. Tests with an autonomous Scania R580 show that the desired curvature can be followed with satisfactory small error, both in a designed slalom path and on a more generic test track. By utilizing future curvature values computed by the MPC, a non-causal feedforward controller can reduce the delay from input to the steering wheel to a measured response in curvature, by almost two thirds, compared to the currently implemented solution. Compared to an open-loop control design, tests in simulation show that a feedback controller can reduce errors in curvature gain. However, with the identified steering dynamics and the improved conversion from steering wheel angle to curvature, no further improvement in the curvature gain was seen when implementing the feedback controller in the test vehicle. Care must also be taken not to introduce instability in the system when the feedback controller is implemented in series with a high-level MPC.Den här rapporten beskriver design och implementering av en regulator med kombinerad framkoppling och återkoppling för förbättrad banföljning av autonoma tunga fordon. Fordonets ratt styrs för att följa en kurvaturreferens beräknad av en överordnad MPC, ansvarig för att minimera avståndet till en planerad bana. Dynamiken i styrningen, från ratten via hjulvinklarna till en mätbar kurvatur för fordonet, är modellerad. En översättning från önskad förstärkning av kurvatur till insignal för rattvinkeln är också framtagen. Tester utförda med en autonom Scania R580 visar att den önskade kurvaturen kan följas med tillfredsställande litet fel, både i en egendesignad slalombana och i en mer generisk testbana. Genom att utnyttja framtida referensvärden för kurvatur beräknade av MPC:n, kan en icke-kausal framkopplande regulator minska fördröjningen från insignal till ratten till en mätbar respons i fordonets kurvatur. Jämfört med den nuvarande lösningen minskas fördröjningen med nästan två tredjedelar. Jämfört med en öppen styrning visar tester i simulering att en återkoppling i regulatorn kan minska stationära fel i kurvatur. Med implementeringen av den identifierade styrdynamiken och den förbättrade översättningen från rattvinkel till kurvatur, syntes dock med återkoppling ingen ytterliggare förbättring i testfordonet. Implementering av den återkopplande regulatorn i serie med den överordnade MPC:n behöver också göras med omsorg för att inte introducera instabilitet i systemet.
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Lu, Ziwei, and Tao Liu. "Design and implementation of brake and steering control functions for an over-actuated vehicle platform." Thesis, KTH, Fordonsdynamik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299361.
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This thesis project is a comprehensive practice to improve a research concept vehicle in both hardware and software aspects. The hardware of the friction brake system is improved to have higher stability and accuracy. The brake force distribution function is implemented to optimize the brake control system. A fault tolerant function based on the Pseudo-inverse control allocation strategy is designed, implemented, and tested to compensate for sudden fault in wheels when driving.Detta examensarbete är ett omfattande arbete att förbättra ett forskningsfordon som heter Research Concept Vehicle (RCV) gällande både hårdvara och mjukvara. Hårdvaran i bromssystemet har förbättrats för bättre stabilitet och noggranhet. Bromskraftsfördelningsfuktionen har implementerats för att optimera bromssystemets reglering. En feltolerant funktion baserad på pseudo-invers reglering har också implementerats och testats för att kunna kompensera plötsliga felfall i hjul under körning.
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Åfeldt, Tom. "Adaptive Steering Behaviour for Heavy Duty Vehicles." Thesis, KTH, Reglerteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215134.
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Today the majority of the driver assistance systems are rule-basedcontrol systems that help the driver control the truck. But driversare looking for something more personal and exible that can controlthe truck in a human way with their own preferences. Machine learningand articial intelligence can help achieve this aim. In this studyArticial Neural Networks are used to model the driver steering behaviourin the Scania Lane Keeping Assist. Based on this, trajectoryplanning and steering wheel torque response are modelled to t thedriver preference. A model predictive controller can be used to maintainstate limitations and to weigh the two modelled driver preferencestogether. Due to the diculties in obtaining an internal plant modelfor the model predictive controller a variant of a PI-controller is addedfor integral action instead. The articial neural network also containsan online learning feature to further customize the t to the driverpreference over time.Idag används till största del regelbaserade reglersystem förförarassistanssystem i lastbilar. Men lastbilschaufförer vill ha någotmer personligt och flexibelt, som kan styra lastbilen på ett mänskligtsätt med förarens egna preferenser. Maskininlärning och artificiell intelligenskan hjälpa till för att uppnå detta mål. I denna studie användsartificiella neurala nätverk för att modellera förarens styrbeteende genomScania Lane Keeping Assist. Med användning av detta modellerasförarens preferenser med avseende på placering på vägbanan och momentpåslag på ratten. En modell prediktiv kontroller kan användas föratt begränsa tillstånd och för att väga de två modellerade preferensernamot varann. Eftersom det var mycket svårt att ta fram den internaprocessmodellen som krävdes för regulatorn används istället en variantav en PI-kontroller för att styra lastbilen. De artificiella neuralanätverken kan också tillåtas att lära sig under körning för att anpassasig till förarens preferenser över tid.
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GHOSH, JYOTISHMAN. "State Estimation and Control of Active Systems for High Performance Vehicles." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2675273.
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In recent days, mechatronic systems are getting integrated in vehicles ever more. While stability and safety systems such as ABS, ESP have pioneered the introduction of such systems in the modern day car, the lowered cost and increased computational power of electronics along with electrification of the various components has fuelled an increase in this trend. The availability of chassis control systems onboard vehicles has been widely studied and exploited for augmenting vehicle stability. At the same time, for the context of high performance and luxury vehicles, chassis control systems offer a vast and untapped potential to improve vehicle handling and the driveability experience. As performance objectives have not been studied very well in the literature, this thesis deals with the problem of control system design for various active chassis control systems with performance as the main objective. A precursor to the control system design is having complete knowledge of the
vehicle states, including those such as the vehicle sideslip angle and the vehicle mass, that cannot be measured directly. The first half of the thesis is dedicated to the development of algorithms for the estimation of these variables in a robust manner. While several estimation methods do exist in the literature, there is still some scope of research in terms of the development of estimation algorithms that have been validated on a test track with extensive experimental testing without using research grade sensors. The advantage of the presented algorithms is that they work
only with CAN-BUS data coming from the standard vehicle ESP sensor cluster. The algorithms are tested rigorously under all possible conditions to guarantee robustness.
The second half of the thesis deals with the design of the control objectives and controllers for the control of an active rear wheel steering system for a high performance supercar and a torque vectoring algorithm for an electric racing vehicle. With the use of an active rear wheel steering, the driver’s confidence in the vehicle improves due a reduction in the lag between the lateral acceleration and the yaw rate, which allows drivers to push the vehicle harder on a racetrack without losing confidence in it. The torque vectoring algorithm controls the motor torques to improve the tire utilisation and increases the net lateral force, which allows professional drivers to set faster lap times.
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Onyango, Stevine Obura. "Behaviour Modelling and System Control with Human in the Loop." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1162/document.
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Malgré le progrès en recherche et développement dans le domaine de système autonome, de tels systèmes nécessitent l’intervention humaine pour résoudre les problèmes imprévus durant l’exécution des tâches par l’utilisateur.Il est donc nécessaire, malgré cette autonomie, de tenir compte du comportement du conducteur et il est difficile d’ignorer l’effet de l’intervention humaine dans le cadre de l’évolution continue de l’environnement et des préférences de l’utilisateur. Afin d’exécuter les opérations selon les attentes de l’opérateur, il est nécessaire d’incorporer dans la commande les besoins de l’utilisateur.Dans les travaux présentés dans cette thèse un modèle comportemental de l’utilisateur est développé et intégré dans la boucle de commande afin d’adapter la commande à l’utilisateur. Ceci est appliqué à la commande des fauteuils électrique et assiste dans la navigation du fauteuil dans un milieu encombré.Le développement du modèle comportemental est basé sur la méthode de potentielles orientées et la détection des obstacles et le comportement du conducteur vs de ces obstacles par l’adaptation duL’étude contribue également au développement d’un modèle dynamique du fauteuil utilisable dans des situations normales et exceptionnelles telle que le dérapage. Ce modèle est développé pour un le cas le plus courant des fauteuil avec roues arrière conductrices utilisant le formalisme Euler Lagrange avec les forces gravitationnelles et sur des surfaces inclinées.Dans la formulation de la commande, le modèle du conducteur est introduit dans la boucle de commande. L’optimalité de la performance est assurée par l’utilisation du commande prédictif généralisé pour le système en temps continue. Les résultats de la simulation démontrent l’efficacité de l’approche proposée pour l’adaptation de la commande au comportement du conducteurAlthough the progressive research and development of autonomous systems is fairly evident, such systems still require human interventions to solve the unforeseen complexities, and clear the uncertainties encountered in the execution of user-tasks. Thus, in spite of the system's autonomy, it may not be possible to absolutely disregard the operator's role. Human intervention, particularly in the control of auto-mobiles, may as well be hard to ignore because of the constantly changing operational context and the evolving nature of the drivers' needs and preferences. In order to execute the autonomous operations in conformity with the operator's expectations, it may be necessary to incorporate the advancing needs and behaviour of the operator in the design. This thesis formulates an operator behaviour model, and integrates the model in the control loop to adapt the functionality of a human-machine system to the operator's behaviour. The study focuses on a powered wheelchair, and contributes to the advancement of steering performance, through background assistance by modelling, empirical estimation and incorporation of the driver's steering behaviour into the control system. The formulation of the steering behaviour model is based on two fundamentals: the general empirical knowledge of wheelchair steering, and the experimental steering data captured by a standard powered wheelchair, on both virtual and real environments. The study considers a reactive directed potential field (DPF) method in the modelling of drivers' risk detection and avoidance behaviour, and applies the ordinary least square procedure in the identification of best-fitting driver parameters. The study also contributes to the development of a dynamic model of the wheelchair, usable under normal and non-normal conditions, by taking into consideration the conventional differential drive wheelchair structure with two front castor wheels. Derivation of the dynamic model, based on the Euler Lagrange formalism, is carried out in two folds: initially by considering the gravitational forces subjected to the wheelchair on inclined configurations with no slipping situations, and finally by incorporating slipping parameters into the model. Determination of the slipping parameters is approached from the geometric perspective, by considering the non-holonomic motions of the wheelchair in the Euclidean space. In the closed-loop model, the input-output feedback controller is proposed for the tracking of user inputs by torque compensation. The optimality of the resulting minimum-phase closed-loop system is then ensured through the performance index of the non-linear continuous-time generalised predictive control (GPC). Simulation results demonstrate the expected behaviour of the wheelchair dynamic model, the steering behaviour model and the assistive capability of the closed-loop system
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Ts`oeu, M. S. "Proton beam steering control system for high precision radiotherapy at iThemba LABS : an investigation on actuator saturation constraints." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5095.
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Includes abstract.Includes bibliographical references (leaves 101-106).
This thesis aims at studying some of the techniques used to deal with constraints with special application to the Proton beam steering control at iThemba LABS. The steering of charged particles occurring in research plants is one of the interests of control systems. In this work an investigation of the algorithm for the control of the proton beam steering system in the radiotherapy treatment facility at iThemba LABS is conducted. This algorithm is intended to autonomously maintain the beam centered with reference to the axis of the beamline, and keep the beam front parallel to the central axis of the beamline as stated by van Tubbergh and De Kock, 2006. Furthermore, the algorithm is responsible for monitoring the distribution of the proton beam, in a plane normal to the beam travel direction.
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Wu, Tahchang Jimmy. "Simulation and analysis of the control system of the hybrid vehicle." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182180337.
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Semsir, Emine Zeynep. "Adaptive Beam Control Of Dual Beam Phased Array Antenna System." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610695/index.pdf.
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In this study, the Dual Beam Phased Array Antenna System designed for COST260* project is upgraded to have the abilities of beam steering, tracking and direction finding by providing the necessary computer codes using C++ Programming Language. The functions of new prototype are tested to verify the operation.
*COST260 project was an adaptive phased array receiving antenna system for satellite communication, which was operating at 11.49-11.678 GHz band.
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Huang, Yanan. "Active Control and Adaptive Estimation of an Optically Trapped Probing System." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250617605.
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Fergani, Soheib. "Commande robuste LPV/H infini multivariable pour la dynamique véhicule." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT053/document.
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L'objectif principale de cette thèse est de développer contrôleurs innovants MIMO pour la dynamique véhicule tout en préservant la stabilité du véhicule dans les situations de conduite critiques. Des stratégies de commandes innovatrices ont été introduites pour résoudre cette problématiques. En effet, ces travaux se base sur travaux l'utilisation de la commande LPV/Hinf pour contrôler simultanément les actionneurs de freinage, braquage et de suspensions pour réaliser les objectives du contrôle.Aussi de stratégies d'estimation du profil de route très intéressant et qui peuvent apporter une solution industrielle très intéressante pour développer des contrôleurs qui assurent adaptative aux différentes conditions de route.Aussi des stratégies de commande tolérante aux défauts actionneurs ont été établi en exploitant les caractéristiques de la commande LPV pour compenser la perte de certains actionneurs (en sachant que la voiture est un système sur actionné). Des implémentations ont été effectuées sur des bancs de test et sur un véhicule réel pour prouver l'efficacité des stratégiesThe main issue of this thesis is to work out new Global Chassis MIMO controllers that enhance the overall dynamics of the vehicle while preserving the vehicle stability in critical driving situations. Many innovative strategies have been explored and finalized to deal with these problematics. Various solutions have been given to deal with the vehicle stability and performance objectives. Indeed, many works based on the LPV/Hinf approach have been developed to control simultaneously the braking, steering and suspension actuators. On the other hand, innovative road profile estimation strategies have been introduced and validated via experimental procedures, providing new cheap and easily implementable techniques to estimate the road profile characteristics. Then, the vehicle control is adapted, depending on the road roughness (since it influences greatly the behaviour and the stability of the car). Several fault tolerant control strategies have been also considered to handle the actuators failures while keeping the vehicle stability, safety and enhancing the dynamical behaviour of the car in dangerous and critical driving situations.The general content of this thesisis as follows :-PART I : Theoretical backgrounds and vehicle modeling.-PART II : Road adaptive control vehicle dynamics.-PART III : Global chassis control using several actuators.Also, during this thesis and using the previous works of the advisors and the thesis results, a Matlab ToolBox "Automotive" has been developed to provide a bench test for the different automotive control studies. Implementations on test beds and real vehicle are also achieved to prove the efficiency of the proposed strategies
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Mousavinejad, Seyed Eman. "Advanced Terminal Sliding Mode Control Approach to Integrated Steer-by-Wire and Differential Braking of Ground Vehicles." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/367350.
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Advances in electronic technology have had a profound impact on the design and development of modern vehicle systems. These advances have provided the basis for a research into active vehicle control paradigm with the aim of improving vehicle safety and its dynamic performance.
The vehicle stability control (VSC) concept has recently been born in response to such a research challenge. Its refinement is looking for an algorithm able of integrating vehicle dynamics control (IVDC) by way of coordinating the active front steering (AFS) system and direct yaw-moment control (DYC) system. Thus, when the vehicle is in the normal driving situation, the AFS system is involved for handling enhancement; however, as the vehicle reaches the handling limits, both the AFS and DYC systems are integrated to ensure the vehicle stability.
Recent research into VSC has indicated that the IVDC concept may be able to enhance the handling and stability of ground vehicle by controlling the main two control objectives, yaw rate and body sideslip angle, effectively in severe cornering manoeuvres and the steady-state condition, and several control strategies have been investigated to design an IVDC system. However, most of these control methods have not been focused on improving the transient response for vehicle yaw rate and sideslip angle tracking controllers in the presence of vehicle dynamics uncertainties and external disturbance. Therefore, further improvement of the transient response for the tracking controllers is still the most needed research topics.Thesis (Masters)
Master of Philosophy (MPhil)
Griffith School of Engineering
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Olofsson, Petter, and Jimmy Utterström. "Hydraulstyrning med konfiguration över Bluetooth." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-122408.
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Denna rapport omfattar konstruktionen av ett fristående drivkort med tillhörande mobilapplikation för styrning och konfiguration av ett hydraulsystem. Projektets syfte var att på beställaren Bosch Rexroth ABs begäran undersöka om pump control module (PCM) - en del ur det existerande Spider 3 styrsystemet - kunde användas som en fristående modul. Hårdvara med en Bluetoothmodul skapades och kopplades mot PCM för att möjliggöra kommunikation via Bluetooth. En mobilapplikation utvecklades i Android studio för att tillåta konfiguration från en mobil enhet. Mjukvaran i PCM modifierades för att kommunicera med Bluetooth-hårdvaran över CAN och även för att tillåta analog styrning av pumpen via en strömstyrd ingång. De grundläggande kraven för systemet uppfylldes och en fungerande prototyp kunde uppvisas vid projektets slut. Prototypen visade stor potential men saknade dock viss funktionalitet som vore önskvärd hos en kommersiell produkt.This report encompasses the development of a standalone drive card with an accompanying mobile application for control and configuration of a hydraulic system. The purpose of the project was to - according to an inquiry from the client Bosch Rexroth - investigate whether the pump control module (PCM) from the existing Spider 3 control system could be used as a standalone module. Hardware including a Bluetooth module was assembled and connected to the PCM to allow communication over Bluetooth Low Energy (BLE). A mobile application where developed in Android Studio to allow configuration from a mobile device. The software of the PCM were modified to communicate with the Bluetooth hardware over CAN and also for allowing analog control of the hydraulic pump through a current controlled input.The basic demands for the system were met and a working prototype could be demonstrated at the end of the project. The prototype did show large potential but was lacking some functionality which would be desirable for a commercial product.
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Sureka, Arihant. "Improvement of an existing Integrated Vehicle Dynamics Control System influencing an urban electric car." Thesis, KTH, Flygdynamik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284446.
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The Integrated Vehicle Dynamics Control (IVDC) concept can influence the vehicle behaviour both longitudinally and laterally with just one upper level control concept and further lower level controllers. This demands for state estimation of the vehicle which also includes estimating parameters of interest for the vehicle dynamicist. The approach to this research is firstly in developing a robust unscented Kalman filter (UKF) estimator for the vehicle side slip tracking and also for cornering stiffness estimation which is then fed to the existing model predictive control allocation (MPCA) controller to enhance the lateral stability of the vehicle for the different manoeuvres studied. Based on these developments, two types of filters are created. One with adaption of distance between center of gravity (COG) and roll center height and another without adaption. The key factor in the estimator development is the time adaptive process covariance matrix for the cornering stiffnesses, with which only the initial values have to be parameterised. Combining this research encompasses effective and adaptive method for a better quality of estimation with a kinematic vehicle model which behaves like a real world vehicle, at least virtually.This study is carried out with the understanding of various optimal estimators, parametric sensitivity analysis and statistical inferences, facilitating a base for robust estimation. Keywords: kalametric, state estimation, design matrix, aliasing, kalman filter, projection algorithm, resolutionKonceptet Integrated Vehicle Dynamics Control (IVDC) kan påverka fordonets beteende både longitudinellt och lateralt med bara ett regler koncept iett övre lager och ytterligare regulatorer på lägre nivåer. Detta kräver tillståndsuppskattning av fordonet som också inkluderar uppskattning av parametrar av intresse för en fordonsdynamiker. Tillvägagångssättet för denna studie är för det första att utveckla en robust tillståndsestimering med hjälp av ett Unscented Kalman Filter (UKF) för att uppskatta ett fordons avdriftsvinkel och även för uppskattning av ett däcks sidkraftskoefficient, vilket sedan används i den befintliga modell-prediktiva regleralgoritmen (MPCA) för att förbättra lateralstabiliteten hos fordonet för de olika studerade manövrarna. Baserat på denna utveckling skapades två typer av filter, ett med anpassning av avståndet mellan tyngdpunkten (COG) och krängcentrumhöjden och ett annat utan anpassning. Nyckelfaktorn i estimeringsutvecklingen är den tidsberoende adaptiva inställningenav processkovariansmatrisen för sidkraftskoefficienterna, med vilken endast de initiala värdena behöver parametriseras. Efter filterutvecklingen identifieras parametrar baserade på en förväntad kundanvändning och en statistisk variansanalys (ANOVA) utförs för att bestämma de mest inflytelserika faktorerna i gruppen. En parameteroptimering utförs för att förbättra uppskattningskvaliteten. Kombinationen av detta arbete omfattar en effektiv och anpassningsbar metod för en bättre uppskattningskvalitet med en kinematisk fordonsmodell som har en fordonsrespons som ett verkligt fordon, åtminstone praktiskt taget. Denna studie har genomförts med förståelse för olika optimala estimatorer, parametrisk känslighetsanalys och statistiska slutsatser, vilket underlättaren bas för robust uppskattning. Nyckelord: kalametric, tillståndsestimering, designmatris, vikningsdistorsion, kalmanfilter,projection algorithm, upplösning
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Liebon, Alexander, and Daniel Rääf. "Raalie steering systems." Thesis, Halmstad University, School of Business and Engineering (SET), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-2525.
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Under HT08 och VT09 har vi under vårt examensarbete tagit fram en ny mekanisk produkt. Det är ett mekaniskt styrsystem för sjukhussängar. Det är ett enkelt och billigt system, och det kommer att underlätta för personalen på sjukhusen runt om i landet. Då produkten gör det lättare för personalen att kontrollera sängen, samt att det nu räcker med en person som utför arbetet med att knuffa sängen.
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Malloci, Ivan. "Sur les systèmes à commutation à deux échelles de temps : une application au contrôle de guidage de bande dans un laminoir à chaud." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2009. http://tel.archives-ouvertes.fr/tel-00439457.
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Dans cette thèse, on s'est attaché à résoudre un certain nombre de problèmes qui apparaissent lorsqu'on traite des problèmes concrets de contrôle: phénomènes à plusieurs échelles de temps, discontinuités de la commande lors du basculement d'un correcteur à un autre, nécessité de concevoir un nombre limité de correcteurs différents malgré une gamme très importante des produits traités. Pour illustrer concrètement les résultats obtenus, nous nous sommes appuyés sur un exemple industriel concret, le contrôle de guidage de bande durant le processus de laminage dans un laminoir à chaud. D'abord, nous proposons une solution convexe au problème de commande optimale linéaire quadratique pour les systèmes linéaires à deux échelles de temps en temps discret. Ensuite, nous établissons des conditions suffisantes, formulées sous la forme d'inégalités matricielles linéaires, qui permettent de vérifier la stabilité d'un système à commutation à deux échelles de temps et de synthétiser des correcteurs stabilisants. Nous proposons aussi dans ce travail une méthode pour minimiser les discontinuités sur la commande dans le cadre des systèmes à commutation. Dans le contexte du contrôle de guidage de bande pour un laminoir à chaud, nous ne pouvons pas négliger l'influence des paramètres incertains, qui sont dus principalement au fait que ce genre de système traite une gamme de produits très large. Donc, dans la synthèse du correcteur, nous prenons en compte ces variations en divisant l'ensemble des produits en plusieurs familles et en synthétisant un correcteur différent pour chaque famille.
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Björklund, Fredrik, and Elin Karlström. "Enabling Testing of Lateral Active Safety Functions in a Multi-rate Hardware in the Loop Environment." Thesis, Linköpings universitet, Fordonssystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139076.
Full textAbstract:
As the development of vehicles moves towards shorter development time, new ways of verifying the vehicle performance is needed in order to begin the verification process at an earlier stage. A great extent of this development regards active safety, which is a collection name for systems that help both avoid accidents and minimize the effects of a collision, e.g brake assist and steering control systems. Development of these active safety functions requires extensive testing and verification in order to guarantee the performance of the functions in different situations. One way of testing these functions is to include them in a Hardware in the Loop simulation, where the involved hardware from the real vehicle are included in the simulation loop. This master thesis investigates the possibility to test lateral active safety functions in a hardware in the loop simulation environment consisting of multiple subsystems working on different frequencies. The subsystems are all dependent of the output from other subsystems, forming an algebraic loop between them. Simulation using multiple hardware and subsystems working on different frequencies introduces latency in the simulation. The effect of the latency is investigated and proposed solutions are presented. In order to enable testing of lateral active safety functions, a steering model which enables the servo motor to steer the vehicle is integrated in the simulation environment and validated.
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Rutherford, Simon John. "Modelling driver nonlinear steering control." Thesis, University of Cambridge, 2007. https://www.repository.cam.ac.uk/handle/1810/252062.
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Westbom, Daniel, and Petter Frejinger. "Yaw control using rear wheel steering." Thesis, Linköping University, Department of Electrical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1463.
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The purpose of this project is to continue the work on a vehicle model developed in ADAMS/Car and applied with the concept of ACM (Autonomous Corner Module). The project is divided up in two parts. The objective of the first part is to setup a co-simulation environment between ADAMS/Car and MATLAB/Simulink, and evaluate the vehicle model. In the second part a yaw controller is developed using only the rear wheel steering possibilities. The controller will be evaluated when it is applied on the vehicle model.
The approach is to develop two models, one simpler in MATLAB/Simulink and one more complex in ADAMS/Car, and verify that they show similar behavior. The models will then be linearized and the control design will be based on the most appropriate linear model. Most of the work has been developing and evaluating the two vehicle models in ADAMS/Car and MATLAB/Simulink.
The result was a working co-simulation environment where an evaluation of two different controllers was made. Due to linearization of the ADAMS model was nsuccessful, the controllers were based on the simpler linear Simulink model. Both controllers show similar results. Tests on the ADAMS model showed that it is hard to control both the yaw rate and body slip only by rear wheel steering.
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Dell'Amico, Alessandro. "On Electrohydraulic Pressure Control for Power Steering Applications : Active Steering for Road Vehicles." Doctoral thesis, Linköpings universitet, Fluida och mekatroniska system, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-124574.
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This thesis deals with the Electrohydraulic Power Steering system for road vehicles, using electronic pressure control valves. With an ever increasing demand for safer vehicles and fewer traffic accidents, steering-related active safety functions are becoming more common in modern vehicles. Future road vehicles will also evolve towards autonomous vehicles, with several safety, environmental and financial benefits. A key component in realising such solutions is active steering. The power steering system was initially developed to ease the driver's workload by assisting in turning the wheels. This is traditionally done through a passive open-centre hydraulic system and heavy trucks must still rely on fluid power, due to the heavy work forces. Since the purpose of the original system is to control the assistive pressure, one way would be to use proportional pressure control valves. Since these are electronically controlled, active steering is possible and with closed-centre, energy efficiency can be significantly improved on. In this work, such a system is analysed in detail with the purpose of investigating the possible use of the system for Boost curve control and position control for autonomous driving. Commercially available valves are investigated since they provide an attractive solution. A model-based approach is adopted, where simulation of the system is an important tool. Another important tool is hardware-in-the-loop simulation. A test rig of an electrohydraulic power steering system, is developed. This work has shown how proportional pressure control valves can be used for Boost curve control and position control and what implications this has on a system level. As it turns out, the valves add a great deal of time lag and with the high gain from the Boost curve, this creates a control challenge. The problem can be handled by tuning the Boost gain, pressure response and damping and has been effectively shown through simulation and experiments. For position control, there is greater freedom to design the controller to fit the system. The pressure response can be made fast enough for this case and the time lag is much less critical.
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Бурлеев, Олег Леонидович. "Усовершенствование фотоэлектрических преобразователей перемещений в компьютерных системах контроля угловых параметров самолета." Thesis, Национальный аэрокосмический университет им. Н. Е. Жуковского "Харьковский авиационный институт", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/19583.
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Диссертация на соискание ученой степени кандидата технических наук по специальности 05.13.05 - компьютерные системы и компоненты. - Национальный технический университет "Харьковский политехнический институт", Харьков, 2016.
Диссертация посвящена решению научно-практической задачи усовершенствования процесса измерения и контроля угловых перемещений рулевых поверхностей самолета. Проанализированы современные методы преобразования угловых перемещений. Описан физический принцип их действия, указаны достоинства и недостатки каждого метода. Рассмотрены наиболее характерные конструкции преобразователей, реализующих оптический метод измерения. В результате анализа устройств определена нехватка преобразователей, которые одновременно объединяют несколько преимуществ, среди которых: малые габариты конструкций, возможность производить высокоточные измерения без внесения изменений в конструкцию объекта исследования, малое количество световодов. Усовершенствованы методы фотоэлектрических измерений угловых перемещений рулевых поверхностей самолета для компьютерных систем контроля. В них, в отличие от существующих, используются такие компоненты, как: зеркало, блок поддержки уровня, кодовый диск с тремя кодирующими дорожками, держатели с оптическими элементами. Применение указанных компонентов позволяет проводить высокоточные измерения и контроль угловых перемещений при отсутствии технологической возможности изменять конструкцию объекта вращения, уменьшить габаритные параметры измерительных устройств. Предложены функциональные схемы устройств, реализующих усовершенствованные методы, а также описаны принципы их действия. Обосновано расширение области их применения. Повышена эффективность процесса измерения угловых перемещений рулевых поверхностей самолета за счет интеграции в компьютерные системы контроля разработанных фотоэлектрических преобразователей.Thesis for scientific the Degree candidate of technical sciences in the specialty 05.13.05 - computer systems and components. - National Technical University "Kharkov Polytechnic Institute", Kharkiv, 2016. The dissertation is devoted to solving scientific and applied tasks of efficiency rising measuring and control processes of angular displacement the aircraft steering surfaces. The methods for photoelectric measuring the angular displacement the aircraft steering surfaces are improved and functional schemes of devices that implement them. The algorithmic tools and software that implements optimization multivariate experiments plans using branch and bound method is developed. The optimal parameters in term of uniform distribution of optical fiber butt ends the angular displacement photoelectric converters with application of mirror are found. First synthesized mathematical models of work the photoelectric converter the aircraft surface steering angle in each control point of the measuring range, which allow to increase accuracy photovoltaic 1' and adapt sensitivity of the measuring device to the design features the aircraft steering surfaces. The architecture of the computer system angular displacement steering control surfaces of the aircraft is and developed.
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Hussein, Ali Abdulsattar. "Photonic Integrated Circuits Utilizing Nano-Electromechanical Systems on Silicon-on-Insulator Platform for Software Defined Networking in Elastic Optical Networks: New Insights Into Phased Array Systems, Tunable WDM, and Cascaded FIR and IIR Architectures." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39592.
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Optical communications systems operate at the limits of their margins to respond to increasing capacity demands. Some of the signal processing functions required must soon operate at speeds beyond electronic implementation. Optical signal processors are fundamentally analog which requires precise control of the operating state. Programmable optical components are consequently essential. The thesis explores and elucidates the properties of meshes of generalized Mach-Zehnder interferometers (GMZIs) amenable to silicon (Si) photonics integration that are based on multimode interference couplers with programmability achieved via voltage controlled phase-shift elements within the interferometer arms to perform a variety of finite impulse response (FIR) and infinite impulse response (IIR) signal processing functions.
The thesis presents a novel class of integrated photonic phased array systems with a single-stage, multistage, and feedback architectures. The designed photonic integrated systems utilize nano-electromechanical-system (NEMS) operated phase shifters of cascaded free suspended slot waveguides that are compact and require a small amount of power to operate. The structure of the integrated photonic phased array switch (IPPAS) elements is organized such that it brings the NEMS-operated phase shifters to the exterior sides of the construction; facilitating electrical connection. The transition slot couplers used to interconnect the phase shifters to the rest of the silicon structure are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the fabric, which is taken as a ground. Phased array processors of 2×2 and 4×4 multiple-input-multiple-output (MIMO) ports are conveniently designed within reasonable footprints native to the current fabrication technologies. The response of the single-stage 4×4 broadband IPPAS element is determined, and its phase synthesis states required for single-throw, double-throw and broadcast routing operations are predicted. The transmission responses of the single-stage wavelength division multiplexing (WDM) processors of 2×2 and 4×4 MIMO ports are simulated. The wavelength steering capability of the transmission interferograms by applying progressive phase shifts through the array of NEMS-operated phase shift elements of the single-stage 4×4 WDM (de)multiplexer is demonstrated.
The advantages of cascading broadband and WDM phased array sections are articulated through several study cases. Five different cascaded phased array architectures are trialed for the construction of non-blocking 4×4 IPPAS broadband switches that are essential elements in the construction of universal photonic processors. A cascaded 2×2 WDM (de)multiplexer that can set the bandwidth of the (de)multiplexed cyclic channels into a binary number of programmable values is demonstrated. The envelope and wavelength modulations of the transmission responses utilizing a cascaded forward structure of three 2×2 sections that can be utilized for the (de)multiplexing of different bandwidth channels are demonstrated providing individual wavelength steering capability of the narrowband and wideband channels and the individual wavelength steering capability of the slow envelope and wavelength modulating functions. Innovative universal 2×2 and 4×4 cascaded phased array processors of advanced high-order architectures that can function as both non-blocking broadband routers and tunable WDM (de)multiplexers with spectrum steering and bandwidth control of the (de)multiplexed demands are introduced.
The multimode interference (MMI) coupler is utilized for the construction of several IIR feedback photonic processors. Tunable photonic feedback processors have the advantage of using less number of MMI couplers compared to their counterparts of FIR forward-path processors saving on the footprint and loss merits. A passive feedback 2×2 (de)multiplexer made of a 4×4 MMI coupler and two loopback paths is proposed. The inclusion of an imbalance in the lengths of the loopback paths of the same symmetrical feedback (de)multiplexer is demonstrated to achieve wavelength modulation of the (de)multiplexed transmission responses that are useful for the (de)multiplexing of different bandwidth channels. Several newly introduced IIR feedback architectures are demonstrated to function similarly as their counterparts of FIR forward-path processors as binary bandwidth variable (de)multiplexers, envelope and wavelength modulation (de)multiplexers, and universal feedback processors.
The investigation provided in this thesis is also supported with dynamic zero-pole evolution analysis in the complex plane of analysis of the studied FIR and IIR photonic processors to enhance understanding the principle of operation. This research expands the prospective for constructing innovative silicon-on-insulator (SOI) based optical processors for applications in modern optical communication systems and programmable elastic optical networks (EONs).
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Unar, Mukhtiar Ali. "Ship steering control using feedforward neural networks." Thesis, University of Glasgow, 1999. http://theses.gla.ac.uk/4493/.
Full textAbstract:
One significant problem in the design of ship steering control systems is that the dynamics of the vessel change with operating conditions such as the forward speed of the vessel, the depth of the water and loading conditions etc. Approaches considered in the past to overcome these difficulties include the use of self adaptive control systems which adjust the control characteristics on a continuous basis to suit the current operating conditions. Artificial neural networks have been receiving considerable attention in recent years and have been considered for a variety of applications where the characteristics of the controlled system change significantly with operating conditions or with time. Such networks have a configuration which remains fixed once the training phase is complete. The resulting controlled systems thus have more predictable characteristics than those which are found in many forms of traditional self-adaptive control systems. In particular, stability bounds can be investigated through simulation studies as with any other form of controller having fixed characteristics. Feedforward neural networks have enjoyed many successful applications in the field of systems and control. These networks include two major categories: multilayer perceptrons and radial basis function networks. In this thesis, we explore the applicability of both of these artificial neural network architectures for automatic steering of ships in a course changing mode of operation. The approach that has been adopted involves the training of a single artificial neural network to represent a series of conventional controllers for different operating conditions. The resulting network thus captures, in a nonlinear fashion, the essential characteristics of all of the conventional controllers. Most of the artificial neural network controllers developed in this thesis are trained with the data generated through simulation studies. However, experience is also gained of developing a neuro controller on the basis of real data gathered from an actual scale model of a supply ship. Another important aspect of this work is the applicability of local model networks for modelling the dynamics of a ship. Local model networks can be regarded as a generalized form of radial basis function networks and have already proved their worth in a number of applications involving the modelling of systems in which the dynamic characteristics can vary significantly with the system operating conditions. The work presented in this thesis indicates that these networks are highly suitable for modelling the dynamics of a ship.
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Odhams, Andrew Murray Charles. "Identification of driver steering and speed control." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612896.
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Бурлєєв, Олег Леонідович. "Вдосконалення фотоелектричних перетворювачів переміщень в комп'ютерних системах контролю кутових параметрів літака." Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/19580.
Full textAbstract:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.13.05 - комп'ютерні системи та компоненти. - Національний технічний університет "Харківський політехнічний інститут", Харків, 2016.
Дисертація присвячена вирішенню науково-прикладної задачі вдосконалення процесу вимірювання і контролю кутових переміщень рульових поверхонь літака. Вдосконалено методи фотоелектричних вимірювань кутових переміщень рульових поверхонь літака для комп’ютерних систем контролю та розроблено функціональні схеми пристроїв, що їх реалізують. Розроблено алгоритмічні та програмні засоби, що реалізують оптимізацію планів багатофакторних експериментів з використанням методу гілок і меж. Знайдено оптимальні, з точки зору рівномірності, параметри розподілу торців світловодів фотоелектричного перетворювача кутових переміщень із застосуванням дзеркала. Вперше одержано математичні моделі роботи фотоелектричного перетворювача кутових переміщень рульової поверхні літака в кожній контрольній точці діапазону вимірювань, що дозволяють підвищити точність фотоелектричного перетворювача до 1´ і адаптувати чутливість вимірювального пристрою до конструктивних особливостей рульових поверхонь літака. Обґрунтовано і розроблено архітектуру комп'ютерної системи контролю кутових переміщень рульових поверхонь літака.Thesis for scientific the Degree candidate of technical sciences in the specialty 05.13.05 - computer systems and components. - National Technical University "Kharkov Polytechnic Institute", Kharkiv, 2016. The dissertation is devoted to solving scientific and applied tasks of efficiency rising measuring and control processes of angular displacement the aircraft steering surfaces. The methods for photoelectric measuring the angular displacement the aircraft steering surfaces are improved and functional schemes of devices that implement them. The algorithmic tools and software that implements optimization multivariate experiments plans using branch and bound method is developed. The optimal parameters in term of uniform distribution of optical fiber butt ends the angular displacement photoelectric converters with application of mirror are found. First synthesized mathematical models of work the photoelectric converter the aircraft surface steering angle in each control point of the measuring range, which allow to increase accuracy photovoltaic 1' and adapt sensitivity of the measuring device to the design features the aircraft steering surfaces. The architecture of the computer system angular displacement steering control surfaces of the aircraft is and developed.
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Chu, Tzyy-Wen. "Eigenstructure analysis of automobile steering dynamics with application to robust four wheel steering control." Thesis, University of Warwick, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246817.
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Senga, Masaaki. "Modeling and analysis of power steering systems." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11770.
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SCALZI, STEFANO. "Integrated control of active steering and electronic differentials in four wheel drive and steering vehicles." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/867.
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La tesi presenta nuovi risultati nel progetto integrato di sistemi di controllo per veicoli dotati di sterzatura attiva dell’asse anteriore e posteriore oppure veicoli dotati di differenziale elettronico e sterzatura attiva dell’asse anteriore. L’integrazione della sterzatura attiva dell’asse anteriore in veicoli autonomi dotati di visione artificiale è stata anch’essa analizzata.
Per i veicoli con quattro ruote sterzanti si è mostrato che la dinamica della velocità laterale e quella di imbardata possono essere disaccoppiate asintoticamente
rispetto ai relativi ingressi di riferimento senza dover ricorrere all’utilizzo di misure di accelerazione laterale, velocità laterale oppure osservatori per tali grandezze. Nella progettazione del controllo dei due angoli di sterzo si sono utilizzati due regolatori proporzionali integrali sulla misura d’errore della velocità di imbardata in aggiunta ad un ulteriore segnale di riferimento relativo alla velocità laterale. Il controllo proposto, oltre a disaccoppiare asintoticamente le dinamiche di sterzo, sopprime i tipici comportamenti oscillanti presenti nel modello semplificato della dinamica di sterzo del veicolo assegnando autovalori stabili e reali.
Per veicoli dotati di differenziale elettronico, posto sia sull’asse anteriore che posteriore, si è proposta una legge di controllo in grado di integrare tale sistema
con la sterzatura attiva dell’angolo di sterzo anteriore con l’obiettivo di migliorare la dinamica del veicolo, sopprimendo le oscillazioni ed allargando la banda passante per la dinamica della velocità di imbardata, ridurre il lavoro del pilota sull’asse di sterzo anteriore e migliorare la sicurezza del veicolo. La strategia di controllo dei differenziali non è limitata alla regolazione della differenza di velocità delle ruote sullo stesso assale ma è integrata con la sterzatura anteriore al fine di generare un momento di imbardata (un controllore proporzionale integrale sulla
velocità di imbardata) in grado di migliorare la dinamica del veicolo riducendone le oscillazioni. L’analisi di stabilità è stata effettuata utilizzando sia la teoria delle perturbazioni singolari che Lyapunov.
Si è inoltre proposto uno schema di integrazione della sterzatura attiva sull’asse anteriore in veicoli autonomi dotati di sistema di visione artificiale. Un sistemabasato su due controllori PID nidificati è stato proggettato per l’inseguimento di traiettorie stradali con un raggio di curvatura che cresce linearmente. In tale controllo un regolatore proporzionale-integrale all’errore di inseguimento della velocità di imbardata garantisce il miglioramento della dinamica del veicolo. Un secondo anello di controllo proporzionale-integrale-derivativo allo spostamento laterale rispetto alla linea di mezzeria, misurato dal sistema di visione, fornisce il riferimento per la velocità di imbardata all’anello di controllo interno.
Per tutti i controlli proposti, al fine di validare i risultati ottenuti ed esplorare
la robustezza e le prestazioni ottenute, si sono realizzate molte simulazioni nell’ ambiente di sviluppo offerto dal CarSim il quale include accurati modelli dinamici
di autoveicoli.This thesis presents new results in the design and the integration of the active front/rear steering control with front/rear electronic differential in four wheel drive and steering vehicles; an application to vision based autonomous lane keeping control is also deployed. In four wheel steering vehicles it is shown that the lateral speed and yaw rate dynamics can be asymptotically decoupled by feeding back longitudinal speed and yaw rate measurements: lateral speed measurements or observers are not required. A proportional-integral (PI) active front steering control and a proportional-integral (PI) active rear steering control from the yaw rate error together with an additive feedforward reference signal for the vehicle sideslip angle can asymptotically decouple the lateral velocity and the yaw rate dynamics, that is the control can set arbitrary steady state values for lateral speed and yaw rate at any longitudinal speed; moreover the PI controls can suppress oscillatory behaviours by assigning real stable eigenvalues to the basic linear model of the vehicle steering dynamics for any value of longitudinal speed in understeering vehicles. The active front steering is also integrated with the front and rear active or semiactive electronically controlled differentials: the goal is to improve vehicle dynamics, by suppressing resonances and enlarging the bandwidth for the yaw rate tracking dynamics, and to reduce the driver effort. Moreover the control law on the electronically controlled differentials is designed in order to improve safety. The control strategy for the electronic differentials is not only aimed at keeping the wheel speed differences at desired values but it is also integrated with the active steering control action (a PI control on the yaw rate error) to produce a yaw moment, based on the yaw rate error, which improves the vehicle steering dynamics since the corresponding eigenvalues can be placed to be all real at every speed to prevent oscillations. The stability analysis is performed using both singular perturbation and Lyapunov techniques in the presence of small parameters which are due to the ratio between the moments of inertia of the wheels and of the vehicle. A control scheme which integrates the active steering action based on the yaw rate error with the lane keeping action based on lateral offsets is also analyzed. A nested PID steering control for lane keeping in vision based autonomous vehicles is designed to perform path following in the case of roads with a curvature which increases linearly with respect to time. No lateral speed measurement is used since it can be hardly measured with high cost and low accuracy and reliability. The designed control input is the steering wheel angle: it is computed on the basis of yaw rate measured by a gyroscope and the lateral offset measured by the vision system as the distance between the road centerline and a virtual point at a fixed distance from the vehicle. A PI active front steering control on the yaw rate tracking error is used to reject constant disturbances and the effect of uncertain parameters while improving vehicle steering dynamics. To integrate the additional lateral offset measure the yaw rate reference is viewed as the control signal in an external control loop: it is designed using a PID control (with an additive double integral action) on the lateral offset to reject the disturbances on the curvature which increase linearly with respect to time. To confirm the results and to explore the robustness all the controls are tested on CarSim vehicle model.
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Johnson, Jay H. "AUV steering parameter identification for improved control design." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA397498.
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Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, June 2001.Thesis advisor(s): Healey, Anthony J. "June 2001." Includes bibliographical references (p. 55). Also Available in print.
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Tan, Wee Kiat. "Horizontal steering control in docking the ARIES AUV." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FTan%5FW.pdf.
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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2003.Thesis advisor(s): Fotis Papoulias, Anthony J. Healey. Includes bibliographical references (p. 83). Also available online.
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Li, Hong. "Measuring systems for active steering of railway vehicles." Thesis, Loughborough University, 2001. https://dspace.lboro.ac.uk/2134/6790.
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This thesis studies measuring systems for active steering of railway vehicles. The aim of the study is to develop state estimation techniques to provide high integrity feedback variables for the active steering of railway vehicles. Practicality and provision of high-integrity data are two important aspects of the work. To avoid the use of expensive sensors and complex instrumentation, practical techniques for estimating vehicle variables are developed where only economical measurements are used and they can be easily implemented. The conventional solid-axle wheelset and wheelset with independently-rotating wheels are studied and their mathematical models are developed. The fundamental stability problem of these two models is analysed from a control engineering viewpoint for studies of actively-controlled wheelsets. The Kalman filters are then developed for these models to estimate all state variables, particularly variables of the wheelset relative to the track such as lateral displacement and yaw angle which are needed for active control. A number of sensing options are also identified, analysed for performance and assessed in a comparative sense. Fault detection and isolation schemes are then studied for the estimation techniques developed. Finally, some applications are considered. The techniques and analysis methods developed for the single wheel pair are extended and applied to a MKII coach and a two-axle railway vehicle. The estimation of cant deficiency for tilting trains is explored, and also the possibility of state estimation for a real profiled wheel.