Dissertations / Theses on the topic 'Autonomous steering'
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Magnusson, Filip. "Evaluating Deep Learning Algorithms for Steering an Autonomous Vehicle." Thesis, Linköpings universitet, Programvara och system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-153450.
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With self-driving cars on the horizon, vehicle autonomy and its problems is a hot topic. In this study we are using convolutional neural networks to make a robot car avoid obstacles. The robot car has a monocular camera, and our approach is to use the images taken by the camera as input, and then output a steering command. Using this method the car is to avoid any object in front of it. In order to lower the amount of training data we use models that are pretrained on ImageNet, a large image database containing millions of images. The model are then trained on our own dataset, which contains of images taken directly by the robot car while driving around. The images are then labeled with the steering command used while taking the image. While training we experiment with using different amounts of frozen layers. A frozen layer is a layer that has been pretrained on ImageNet, but are not trained on our dataset. The Xception, MobileNet and VGG16 architectures are tested and compared to each other. We find that a lower amount of frozen layer produces better results, and our best model, which used the Xception architecture, achieved 81.19% accuracy on our test set. During a qualitative test the car avoid collisions 78.57% of the time.
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Brown, William Shaler. "Technology for Designing the Steering Subsystem Component of an Autonomous Vehicle." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34960.
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Autonomous vehicles offer means to complete unsafe military operations without endangering the lives of soldiers. Such solutions have fueled many efforts towards designing autonomous, or unmanned, systems. Military and academic research efforts alike continue to focus on developing these systems. While many different autonomous vehicles have been introduced, however, such complex systems have limited drive-by-wire operability. The complete process to up-fit a vehicle to fully autonomous operation involves the design, up-fit, testing and verification of many different subsystems. The objective of this thesis is to design and model an autonomous steering system requiring little modifications to an existing steering system. It is desirable to still operate the vehicle manually as well as preserve the vehicleâ s visual appearance. Up-fit and implementation of the designed steering system and verification of its functionality has been documented as well. Utilization of the supplied controller and software has enabled the testing and characterization of the system. The proposed design offers a solution to a wide variety of wheeled vehicles steered via the traditional and common steering wheel method. In addition, modifications have been made to an existing simulation of an unmanned vehicle in a military testbed environment (Fort Benning). The simulation accounts for the control methodology as it has been designed and tested with, which offers the ability to analyze the dynamics of the unmanned system.Master of Science
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Meidenbauer, Kennneth Richard. "An Investigation of the Clothoid Steering Model for Autonomous Vehicles." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34279.
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The clothoid, also known as the Cornu spiral, is a curve generated by linearly increasing or decreasing curvature as a function of arc length. The clothoid has been widely accepted as a logical curve for transitioning from straight segments to circle arcs in roads and railways, because a vehicle following the curve at constant speed will have a constant change of centripetal acceleration. Clothoids have also been widely adopted in planning potential paths for autonomous vehicle navigation. They have been viewed as useful representations of possible trajectories that are dynamically feasible. Surprisingly, the assumptions that underlie this choice appear to be lightly treated or ignored in past literature.
This thesis will examine three key assumptions that are implicitly made when assuming that a vehicle will follow a clothoid path. The first assumption is that the vehicle's steering mechanism will produce a linear change in turning radius for a constant rate input. This assumption is loosely referred to as the "bicycle model" and it relates directly to the kinematic parameters of the steering mechanism. The second assumption is that the steering actuator can provide a constant steering velocity. In other words, the actuator controlling the steering motion can instantaneously change from one rate to another. The third assumption is that the vehicle is traveling at a constant velocity. By definition, the clothoid is a perfect representation of a vehicle traveling at constant velocity with a constant rate of change in steering curvature. The goal of this research was to examine the accuracy of these assumptions for a typical Ackermann-steered ground vehicle. Both theoretical and experimental results are presented.
The vehicle that was used as an example in this study was a modified Club Car Pioneer XRT 1500. This Ackermann-steered vehicle was modified for autonomous navigation and was one of Virginia Tech's entries in the DARPA 2005 Grand Challenge. As in typical operation, path planning was conducted using the classic clothoid curve model. The vehicle was then commanded to drive a selected path, but with variations in speed and steering rate that are inherent to the real system. The validity of the three assumptions discussed above were examined by comparing the actual vehicle response to the planned clothoid.
This study determined that the actual paths driven by the vehicle were generally a close match to the originally planned theoretical clothoid path. In this study, the actual kinematics of the Ackermann vehicle steering system had only a small effect on the driven path. This indicates that the bicycle model is a reasonable simplification, at least for the case studied. The assumption of constant velocity actuation of the steering system also proved to be reasonably accurate. The greatest deviation from the planned clothoid path resulted from the nonlinear velocity of the vehicle along the path, especially when accelerating from a stop. Nevertheless, the clothoid path plan generally seems to be a good representation of actual vehicle motion, especially when the planned path is updated frequently.Master of Science
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Haglund, Sebastian, and Henrik Johansson. "Steering Control During μ-split Braking for an Autonomous Heavy Road Vehicle." Thesis, Linköpings universitet, Fordonssystem, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166962.
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A critical maneuver for a heavy vehicle is braking with different friction on the left and right hand side of the vehicle, called μ-split. This results in an unwanted yaw torque acting on the vehicle. During this situation, the driver maintains the lateral stability and follows the desired path by corrective steering. In anautonomous heavy vehicle the system must handle this situation by itself. The purpose of this thesis is to analyze how an autonomous vehicle can detect a μ-split situation and then use steering control to maintain its path and stability. Two methods for detecting a μ-split situation are presented where one is based on vehicle kinematics, this detector utilizes the difference in wheel speed between the left and right hand side of the vehicle. The other detector is based on lateral vehicle dynamics, this method uses a sliding mode observer to detect unexpected changes in the yaw rate signal. The detectors were tested in a real vehicle and the results showed that the kinematic detector was fast but had a small risk of false detection, while the dynamic detector was slower but more robust. An analysis of the desired steering behavior showed that the steady state during μ-split braking is to drive with a non zero body slip. If a kinematic path follower is used with kinematic error dynamics this will lead to a contradicting behavior since the body slip is equal to the heading error during straight line braking, assuming that the velocity vector of the vehicle is parallel to the path. Simulations showed that during a μ-split situation the Linear Quadratic pathfollower based on kinematic error dynamics manages to follow the path with a non zero body slip while keeping the path errors small. It has also been shown how the detection of a μ-split situation can be used to change control strategy. By introducing active yaw control or change the tuning on the controller after a detection a better result could be achieved.
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Lerider, Malcolm. "Autonomous Calibration and Control of Mine Vehicles." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-91034.
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The mining industry desires to cut costs and to operate in more dangerous mines, which is why companies such as Atlas Copco are developing autonomous vehicles. The problem to navigate autonomously is however complex, so the vehicles have in the recent years become more intelligent; the number of computers, actuators and sensors are increasing. For example, an autonomous LHD (Loading – Hauling – Dump) vehicle has sensors including: inertial measurement unit (IMU), odometer, hinge angle sensor, laser range finders and cameras. The parameters for the sensors needs to be calibrated before the vehicle can be used in a mine. There are also a number of electrical currents which needs to be calibrated for the actuators.The calibration of parameters has traditionally been made manually, but Atlas Copco realizes that manual calibration is not feasible once the sales of intelligent mine vehicles increases. Effort is therefore put into automation of the calibration procedures.Interviews with employees were carried out at Atlas Copco to identify the most time consuming procedures during calibration and installation of autonomous mine vehicles. The calibration of steering currents was not only identified as the most time consuming procedure, but also as one of the most complex procedures.The goal of this thesis is to enable easier and quicker installation of mine vehicles. This is done through investigation of methods for automatic calibration of steering currents. The problem is approached from two angles: a grey box model using system identification and a black box model using neural network with resilient backpropagation. The models are compared to a search algorithm, used for simulation of the manual calibration method. In the end, the models are evaluated with regard to performance and ease of implementation.The hypothesis was that the more complex grey box or black box model would have higher accuracy than a simple search algorithm. However, the search algorithm proves to outperform the other models both with regard to accuracy and calibration time, and is also easier to implement. The search algorithm is thus suggested to be implemented instead of a complex model. Moreover, it is suggested that a straightforward mapping of 20 currents may outperform even the search calibration. It is also concluded that calibration of steering currents can be done when the vehicle is standing still.
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Hawkinson, Todd D. "Multiple input sliding mode control for autonomous diving and steering of underwater vehicles." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA241935.
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Thesis (M.S. in Mechanical Engineering and Mechanical Engineer)--Naval Postgraduate School, December 1990.Thesis Advisor(s): Papoulias, Fotis A. "December 1990." Description based on title screen as viewed on March 31, 2010. DTIC Identifier(s): Autonomous, Guidance Control, Theses. Author(s) subject terms: Autonomous Underwater Vehicles, AUV, Guidance Control. Includes bibliographical references (p. 195). Also available in print.
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Campbell, Stefan F. (Stefan Forrest). "Steering control of an autonomous ground vehicle with application to the DARPA Urban Challenge." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42301.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (p. 156-157).
Fundamental to the design of an Ackerman steered autonomous ground vehicle is the development of a low-level controller that effectively performs trajectory or path tracking. Though ample literature is available on various methods for controlling ground vehicles, little information is presented on the implementation and tuning of such controllers. Moreover, few sources extend ground vehicle control to driving in reverse. This work presents a novel approach to the implementation of the traditional "pure pursuit" style controller in which a dynamic vehicle model is used to map from the path curvature specified by the pure pursuit algorithm to the vehicle's actual steering angle. Additionally, an analytical methodology using a linear model of straight-line path following is used to tune the pure pursuit look-ahead distance. This pure pursuit controller is then contrasted with a simulation-based controller that uses a kinematic model to predict the vehicle's response to a series of different steering inputs; a performance metric is used to select the best command given these predictions. Successful trajectory control results are presented at speeds up to 22 mph. The second focus of this work is the control of a front-wheel steered vehicle driving in reverse. Novel to this work is the presentation of pure pursuit as a stable solution to this problem. Pure pursuit is then contrasted with the mechanism-based controller that was developed by Patwardhan et al. at the University of California Berkeley. In presenting this controller, a new method employing a linear kinematic vehicle model is used to tune the controller parameters. It is then shown that, under specific conditions, the mechanism-based controller and the pure pursuit controller are identical. Both controllers are then compared with the simulation-based controller adapted for driving in reverse.
(cont.) Results are presented at speeds up to 6.7 mph. Results for the implementation of these controllers were collected using a 2006 Land Rover LR3 developed for MIT's entry into the 2007 DARPA Urban Challenge. Results ultimately illustrate the respective strengths and weaknesses of the pure pursuit class of controllers.
by Stefan F. Campbell.
S.M.
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Wetterlind, Victor. "Concept development of steering column : Accommodating business commuters in a level four autonomous car." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-68135.
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This thesis reports on a collaborative concept development with Volvo Car Corporation. The problem underlying the concept development was to innovate a steering device for a level-four autonomous car. Specifically: How can the steering wheel and its mount be designed to give the driver more room when the car can drive itself? The product development process was combined with a hybrid strategy view, both an in-side-out and outside-in approach. The thesis is written by the project leader Victor Wetterlind for his bachelor’s thesis in Innovation and design engineering at Karlstad University. This with supervision from postdoctoral researcher within innovation, Jakob Trischler and examiner, professor in manufacturing engineering, Leo de Vin. The thesis corresponds to 22.5 hp and belongs to the faculty of health, science and technology. Along the project, analysis of field tests, research on related subjects, discussions with experts and lead-users were held. Concepts were created with both individual and group-based methods. The project has used computer-aided design as a tool to test concepts along the evaluation phase. 2-D and 3-D models were used to perceived size, proportion and design as well as for digitally verifying kinematics and function. After several evaluation iterations and concept refinement, a concept recommendation was done to the company in the shape of a presentation and 3D-model.
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GUIDOLINI, R. "A NEURAL-BASED MODEL PREDICTIVE CONTROL TO TACKLE STEERING DELAY OF THE IARA AUTONOMOUS CAR." Universidade Federal do Espírito Santo, 2017. http://repositorio.ufes.br/handle/10/9852.
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Previous issue date: 2017-09-04Neste trabalho, propomos uma abordagem de Controle Preditivo Baseado em Modelo Neural (Neural Based Model Predictive Control - N-MPC) para lidar com atrasos na planta de direção de carros autônomos. Examinamos a abordagem N-MPC como uma alternativa para a implementação do subsistema de controle de direção da Intelligent and Autonomous Robotic Automobile (IARA). Para isso, comparamos a solução padrão, baseada na abordagem de controle Proporcional Integral Derivativo (PID), com a abordagem N-MPC. O subsistema de controle de direção PID funciona bem na IARA para velocidades de até 25 km/h. No entanto, acima desta velocidade, atrasos na Planta de Direção da IARA são muito elevados para permitir uma operação adequada usando uma abordagem PID. Modelamos a Planta de Direção da IARA usando uma rede neural e empregamos esse modelo neural na abordagem N-MPC. A abordagem N-MPC superou a abordagem PID reduzindo o impacto de atrasos na Planta de Direção de IARA e permitindo a operação autônoma da IARA em velocidades de até 37 km/h um aumento de 48% na velocidade máxima estável
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Striedieck, Robert. "LOOPHOLE : How sports cars will find a way to survive the autonomous future." Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-136854.
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What will happen to sport cars once our society and infrastructure allow for a fully autonomous transport systems? My concern for the ”survival of the sports car” clearly originates from an emotional viewpoint rather than a reasonable argument. We know about the benefits that come along with autonomy but that doesn’t make the fear of loosing the emotional side of driving unfounded. My aim was to create a scenario that allows both reason and emotion to coexist and furthermore to benefit from each other rather than to create a conflict. The result is a PORSCHE for 2040 that shows an exciting concept for steering fully autonomous cars of the future. It combines the benefits of autonomy with the emotions of sports cars.
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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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Bahrke, Fredric G. "On-line identification of the speed, steering and diving response parameters of an autonomous underwater vehicle from experimental data." Thesis, Monterey, Calif. : Naval Postgraduate School, 1992. http://handle.dtic.mil/100.2/ADA252703.
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Thesis (M.S. in Mechanical Engineering and Mechanical Engineer)--Naval Postgraduate School, March 1992.Thesis Advisor: Healey, Anthony J. "March 1992." Includes bibliographical references (p. 157-159). Also available in print.
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Sinyukov, Dmitry Aleksandrovich. "Semi-autonomous robotic wheelchair controlled with low throughput human- machine interfaces." Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-dissertations/242.
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For a wide range of people with limited upper- and lower-body mobility, interaction with robots remains a challenging problem. Due to various health conditions, they are often unable to use standard joystick interface, most of wheelchairs are equipped with. To accommodate this audience, a number of alternative human-machine interfaces have been designed, such as single switch, sip-and-puff, brain-computer interfaces. They are known as low throughput interfaces referring to the amount of information that an operator can pass into the machine. Using them to control a wheelchair poses a number of challenges. This thesis makes several contributions towards the design of robotic wheelchairs controlled via low throughput human-machine interfaces: (1) To improve wheelchair motion control, an adaptive controller with online parameter estimation is developed for a differentially driven wheelchair. (2) Steering control scheme is designed that provides a unified framework integrating different types of low throughput human-machine interfaces with an obstacle avoidance mechanism. (3) A novel approach to the design of control systems with low throughput human-machine interfaces has been proposed. Based on the approach, position control scheme for a holonomic robot that aims to probabilistically minimize time to destination is developed and tested in simulation. The scheme is adopted for a real differentially driven wheelchair. In contrast to other methods, the proposed scheme allows to use prior information about the user habits, but does not restrict navigation to a set of pre-defined points, and parallelizes the inference and motion reducing the navigation time. (4) To enable the real time operation of the position control, a high-performance algorithm for single-source any-angle path planning on a grid has been developed. By abandoning the graph model and introducing discrete geometric primitives to represent the propagating wave front, we were able to design a planning algorithm that uses only integer addition and bit shifting. Experiments revealed a significant performance advantage. Several modifications, including optimal and multithreaded implementations, are also presented.
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Beckman, Erik, and Linus Harenius. "Monitored Neural Networks for Autonomous Articulated Machines." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-48708.
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Being able to safely control autonomous heavy machinery is of uttermost importance for the conversion of traditional machines to autonomous machines. With the continuous growth of autonomous vehicles around the globe, an increasing effort has been put into certifying autonomous vehicles in terms of reliability and safety. In this thesis, we will investigate the problem with a deviation from the planned path for an autonomous hauler from Volvo Construction Equipment. The autonomous hauler has an error within the kinematic model, the feed-forward curvature-steering controller, due to a slip-effect that comes with the third wheel-axle. The deviation can especially be seen in sharp curves, where the deviation needs to be decreased in order to make the autonomous hauler more dependable and achieve an increased accuracy when following any given path. The aim of the thesis is to develop a fully functional Artificial Neural Network that has a new steering angle as output. The hypothesis for this thesis is to use an ANN to mimic the steering of a human driver, since a real driver compensates for the slipping behavior; both because the operator knows where on the road the machine is and also in the way that a human thinks many steps ahead whilst driving. This proposed ANN will have a monitor function which ensures that the steering angle command operates within its boundaries. Hence this thesis implies that it is indeed possible to ensure that the ANN performs reliably with the help of a monitor function in a simulated environment and can thus be used in dependable systems.
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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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Siponmaa, Stefan. "Utvärdering av styrbeteenden för grupper av navigerande agenter." Thesis, Högskolan i Skövde, Institutionen för kommunikation och information, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-8169.
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Detta examensarbete undersöker navigering för grupper av autonoma agenter i dataspelsmiljöer. Genom att kombinera olika styrbeteenden och beräkningsmodeller utvärderar arbetet vilken av dessa tekniker som är mest effektiv med avseende på tid och vägval i trånga spelmiljöer. En experimentmiljö har utvecklats som implementerar fyra stycken tekniker och utvärderar dessa i tre olika miljöer med 10 respektive 50 agenter som navigerar genom miljön. Som grund använder samtliga tekniker ett vägföljningsbeteende och ett flockbeteende. Det som skiljer teknikerna åt är vilken beräkningsmodell som används samt att två av teknikerna använder ett väggundvikelsebeteende. Resultatet visar att alla tekniker är användbara men att den mer avancerade beräkningsmodellen ger ett bättre resultat överlag. Väggundvikelsebeteendet bidrar också till ett bättre resultat och gör alltså nytta i de miljöer som använts. Ett problem med styrbeteenden är dock balanseringen av vikterna som används i teknikerna och det kan krävas mycket finjustering innan man får ett bra beteende.
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de, Saxe Christopher Charles. "Vision-based trailer pose estimation for articulated vehicles." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/268169.
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Articulated Heavy Goods Vehicles (HGVs) are more efficient than conventional rigid lorries, but exhibit reduced low-speed manoeuvrability and high-speed stability. Technologies such as autonomous reversing and path-following trailer steering can mitigate this, but practical limitations of the available sensing technologies restrict their commercialisation potential. This dissertation describes the development of practical vision-based articulation angle and trailer off-tracking sensing for HGVs. Chapter 1 provides a background and literature review, covering important vehicle technologies, existing commercial and experimental sensors for articulation angle and off-tracking measurement, and relevant vision-based technologies. This is followed by an introduction to pertinent computer vision theory and terminology in Chapter 2. Chapter 3 describes the development and simulation-based assessment of an articulation angle sensing concept. It utilises a rear-facing camera mounted behind the truck or tractor, and one of two proposed image processing methods: template-matching and Parallel Tracking and Mapping (PTAM). The PTAM-based method was shown to be the more accurate and versatile method in full-scale vehicle tests. RMS measurement errors of 0.4-1.6° were observed in tests on a tractor semi-trailer (Chapter 4), and 0.8-2.4° in tests on a Nordic combination with two articulation points (Chapter 5). The system requires no truck-trailer communication links or artificial markers, and is compatible with multiple trailer shapes, but was found to have increasing errors at higher articulation angles. Chapter 6 describes the development and simulation-based assessment of a trailer off-tracking sensing concept, which utilises a trailer-mounted stereo camera pair and visual odometry. The concept was evaluated in full-scale tests on a tractor semi-trailer combination in which camera location and stereo baseline were varied, presented in Chapter 7. RMS measurement errors of 0.11-0.13 m were obtained in some tests, but a sensitivity to camera alignment was discovered in others which negatively affected results. A very stiff stereo camera mount with a sub-0.5 m baseline is suggested for future experiments. A summary of the main conclusions, a review of the objectives, and recommendations for future work are given in Chapter 8. Recommendations include further refinement of both sensors, an investigation into lighting sensitivity, and alternative applications of the sensors.
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Romera, Orengo Javier. "Analysis of vehicle ergonomics using a driving test routine in the DHM tool IPS IMMA." Thesis, Högskolan i Skövde, Institutionen för ingenjörsvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-19055.
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The objective of this project is to develop a driving test using a Digital Human Modeling tool (DHM), specifically IPS IMMA, which will allow the evaluation of the ergonomics of the interior of vehicles as currently demanded by the automotive companies. Thus, improving both the design and the design process. This will involve a study of the driving and the tasks carried out by a real person to end up programming them in the DHM software. Based on this study an interface is suggested that guides engineers or ergonomists to design their own driving tests and enable them to evaluate their own designs without a high specialization in DHM tools and software. Taking into account the already present autonomous cars and their future development, the conceptual design of a two positions steering wheel (autonomous/manual driving) will be introduced as an example to be added in the driving test. This example is intended to show how DHM tools can be used to evaluate different designs solutions in early stages of the product development process. This project will be a contribution to one of the sections of the ADOPTIVE project carried out at the University of Skövde and in collaboration with Swedish automotive companies.
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Alekseeva, Natalia Mihajlovna, and Natalia Alekseeva. "Developing an autosteering of road motor vehicles in slippery road conditions." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13155942/?lang=0, 2020. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13155942/?lang=0.
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In the nearest future, the human driver is viewed as a reliable backup even for the fully automated road motor vehicles (cars). Indeed, the driver is assumed to swiftly take the control of the car in cases of suddenly occurring (i) challenging environmental conditions, (ii) complex unforeseen driving situations, or (iii) degradation of performance of the car. However, due to the cognitive overload in such a sudden, stressful takeover of the control, the driver would often experience the startle effect, which usually results in an unconscious, instinctive, yet incorrect response. An extreme case of startle is freezing, in which the driver might be incapable to respond to the sudden takeover of control at all. The possible approaches to alleviate the startle during the takeover of control (i.e., the automation startle) include an offset- (i.e., either early- or delayed-), gradual yielding the controls to the driver. In the cases considered above, however, these approaches are hardly applicable because of (i) the presumed unpredictability of the events that result in the need of takeover of control, and (ii) the severe time constraints of the latter. Conversely, the objective of our research is to propose an approach of minimizing the need of yielding the control to the driver in challenging environmental conditions by guaranteeing an adequate automated control in these conditions. Focusing on slippery roads as an instance of challenging conditions, and steering control as an instance of control, we aim at developing such an automated steering that controls the car adequately in various road surfaces featuring low friction coefficients without the need of driver’s intervention.In order to develop such an automated steering we employed an in-house evolutionary computation framework – XML-based genetic programming (XGP) – which offers a flexible, portable, and human readable representation of the evolved optimal steering functions. The trial runs of the evolved steering functions were performed in the Open Source Racing Car Simulator (TORCS), which features a realistic, yet computationally efficient simulation of the car and its environment. The obtained experimental results indicate that due to the challenging dynamics of the unstable car on slippery roads, neither the canonical (tuned) servo-control (as a variant of PD) nor the (tuned) PID-controller could control the car adequately on slippery roads. On the other hand, the controller, featuring a relaxed, arbitrary structure evolved by XGP outperforms both the servo- and PID controllers in that it results in a minimal deviation of the car from its intended trajectory in rainy, snowy, and icy road conditions. Moreover, the evolved steering that employs anticipated perceptions is even superior as it could anticipate the imminent understeering of the car at the entry of the turns and consequently – to compensate for such an understeering by proactively turning the steering wheels in advance – well before entering the turn. The obtained results suggest a human competitiveness of the evolved automated steering as it outperforms the commonly used alternative steering controllers proposed by human experts. The research could be viewed as a step towards the evolutionary development of automated steering of cars in challenging environmental conditions.博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
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Ayala, Jaimes Gerardo. "Supervision of over-actuated steering system of mobile omnidrive heavy vehicle." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10216.
Full textAbstract:
Ce travail se concentre sur la modélisation et l'analyse d'un système de direction sur-motorisé d'un (véhicule) poids lourd omnidrive. Il fait partie d'un robot appelé RobuTAINeR, il est utilisé pour le transport conteneurs de 12 mètres à l'intérieur des espaces confinés à terminaux maritimes. Dans cette classe de robots, la direction et la roue jouent un rôle crucial pour la navigation autonome, par conséquent, il est une nécessité pour comprendre et modéliser les capacités de mouvement omnidirectionnel, la commutation des comportements dynamiques, et ses zones multi-domaines: électrique, mécanique, hydrodynamique, etc. La technique Bond Graph est une méthodologie unificatrice pour réaliser et analyser les systèmes physiques aussi bien que l'échange énergétique, ce qui fait possible l'exploiter non seulement pour la modélisation, mais aussi pour la détection de défauts et l'isolement. La validation du modèle a été réalisée avec la simulation en temps réel, établie à partir de données réelles obtenues dans le simulateur SCANeR Studio et par rapport à la simulation sur le logiciel 20sim. Cette technique est utilisée pour modéliser des systèmes complexes comme: le contrôle de la direction hydraulique; la partie électromécanique du système de traction; la dynamique longitudinale, latérale et de lacet dans le centre de gravité du robot; et les forces latérales et longitudinales présentées dans le pneu-sol. Le diagnostic est appliqué avec le modèle hybride qui est appelé Diagnostic Bond Graph. Ainsi, un autre objectif est de modéliser et d'améliorer la robustesse de la détection de défaut en présence d'incertitudes paramétriques afin de réduire les fausses alarmesThis work focuses on the modeling and analysis of an over-actuated steering system of a mobile omnidrive heavy vehicle that is part of a wheeled robot called RobuTAINeR. This robot is used for transporting 12-meters containers inside confined spaces of maritime terminals. In this class of robots, the steering and wheel play a crucial role for the autonomous navigation; hence, there is a necessity to understand and model the omnidirectional motion capabilities, switching dynamic behaviors, and its multi-domain areas: electrical, mechanical, hydrodynamic, etc. The Bond Graph technique is a unifying methodology to perform and analyze physical systems, where there is energy exchange, not only suitable for modeling but also for Fault Detection and Isolation. The validation of this model has been done with real-time simulation, based on real data integrated into the professional simulator SCANeR Studio and compared with the simulation on 20Sim. This professional tool is used to model complex systems such as the control of the hydraulic steering; the electromechanical section of the traction system; the longitudinal, lateral, and yaw dynamics of the robot motion concerning its center of gravity; and the lateral and longitudinal forces presented in the tire-ground. The diagnosis is applied to the hybrid model which is called Diagnostic Bond Graph. Thus, another objective is to model and improve the robustness of fault detection in the presence of parametric uncertainties in order to reduce false alarms
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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.
Full textAbstract:
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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FERRARIO, SUSANNA. "LAVORO AUTONOMO E INTERESSI COLLETTIVI: RAPPRESENTANZA, ORGANIZZAZIONE E AZIONE SINDACALE DI TUTELA." Doctoral thesis, Università Cattolica del Sacro Cuore, 2008. http://hdl.handle.net/10280/257.
Full textAbstract:
La ricerca prende avvio dalla ricostruzione dei processi socio-economici che hanno portato alla crisi del modo di produzione taylorista-fordista. Muovendo da tali riflessioni, si constata come le imprese “post-fordiste” si avvalgano in misura crescente di lavoratori autonomi, un tempo coordinati e continuativi e, oggi, a progetto (artt. 61 e ss., d.lgs. 276/2003).
Tali collaboratori sono, dunque, soggetti ad un potere (contrattuale) di coordinamento del committente che, alle volte, si somma ad una condizione di dipendenza economica dal committente medesimo.
Si crea, quindi, una differenziazione interna all'area dell'autonomia coordinata che non pare adeguatamente valorizzata dal legislatore ordinario, ma che sembra interessare i sindacati.
Il dato reale vede, infatti, agire rappresentanze varie, sicché occorre circoscrivere l'ambito di applicabilità degli artt. 39 e 40 Cost. L'assenza di un genuino interesse collettivo e di un'effettiva attività di autotutela inducono a ritenere che i collaboratori “forti” e il relativo associazionismo possano beneficiare delle sole tutele poste dagli artt. 2, 18 e 41 Cost.
A conclusione si affrontano le problematiche che la ricostruzione così svolta solleva, ovverosia come garantire l'effettività delle tutele riconosciute al sindacalismo dei collaboratori “deboli” e come contemperare l'associazionismo dei collaboratori “forti” con il diritto antitrust comunitario.The search starts with the reconstruction of socio-economic processes. Moving from these reflections, it's possible to see that today's companies take advantage of increasingly self-employed coordinated and continuous and, after d.lgs. 276/2003 “lavoratori a progetto”. These employees are, therefore, subject to a power (contractual) coordination of the customer that, at times, it adds up to a state of economic dependence by the same. It then creates an internal differentiation into autonomy area that does not seem properly valued by the ordinary legislator, but that seems to involve trade unions. Given that in reality there are different representations, we move to circumscribe the scope of applicability of the Arts. 39 and 40 Const. The absence of a genuine interest and genuine self activities suggest that employees "strong" and its associations can only benefit from the protections posed by Arts. 2, 18 and 41 Const. At the end tackling the problems so that the reconstruction turn raises, namely how to ensure the effectiveness of the safeguards recognized unionism collaborators "weak" and reconcile the associations of employees "strong" with the antitrust law.
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FERRARIO, SUSANNA. "LAVORO AUTONOMO E INTERESSI COLLETTIVI: RAPPRESENTANZA, ORGANIZZAZIONE E AZIONE SINDACALE DI TUTELA." Doctoral thesis, Università Cattolica del Sacro Cuore, 2008. http://hdl.handle.net/10280/257.
Full textAbstract:
La ricerca prende avvio dalla ricostruzione dei processi socio-economici che hanno portato alla crisi del modo di produzione taylorista-fordista. Muovendo da tali riflessioni, si constata come le imprese “post-fordiste” si avvalgano in misura crescente di lavoratori autonomi, un tempo coordinati e continuativi e, oggi, a progetto (artt. 61 e ss., d.lgs. 276/2003).
Tali collaboratori sono, dunque, soggetti ad un potere (contrattuale) di coordinamento del committente che, alle volte, si somma ad una condizione di dipendenza economica dal committente medesimo.
Si crea, quindi, una differenziazione interna all'area dell'autonomia coordinata che non pare adeguatamente valorizzata dal legislatore ordinario, ma che sembra interessare i sindacati.
Il dato reale vede, infatti, agire rappresentanze varie, sicché occorre circoscrivere l'ambito di applicabilità degli artt. 39 e 40 Cost. L'assenza di un genuino interesse collettivo e di un'effettiva attività di autotutela inducono a ritenere che i collaboratori “forti” e il relativo associazionismo possano beneficiare delle sole tutele poste dagli artt. 2, 18 e 41 Cost.
A conclusione si affrontano le problematiche che la ricostruzione così svolta solleva, ovverosia come garantire l'effettività delle tutele riconosciute al sindacalismo dei collaboratori “deboli” e come contemperare l'associazionismo dei collaboratori “forti” con il diritto antitrust comunitario.The search starts with the reconstruction of socio-economic processes. Moving from these reflections, it's possible to see that today's companies take advantage of increasingly self-employed coordinated and continuous and, after d.lgs. 276/2003 “lavoratori a progetto”. These employees are, therefore, subject to a power (contractual) coordination of the customer that, at times, it adds up to a state of economic dependence by the same. It then creates an internal differentiation into autonomy area that does not seem properly valued by the ordinary legislator, but that seems to involve trade unions. Given that in reality there are different representations, we move to circumscribe the scope of applicability of the Arts. 39 and 40 Const. The absence of a genuine interest and genuine self activities suggest that employees "strong" and its associations can only benefit from the protections posed by Arts. 2, 18 and 41 Const. At the end tackling the problems so that the reconstruction turn raises, namely how to ensure the effectiveness of the safeguards recognized unionism collaborators "weak" and reconcile the associations of employees "strong" with the antitrust law.
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Botha, Theunis R. "High speed autonomous off-road vehicle steering." Diss., 2011. http://hdl.handle.net/2263/29665.
Full textAbstract:
High speed cornering of an off-road vehicle poses considerable challenges to the development of an autonomous vehicle due to the non-linear dynamics of the tyre road interface as well as those of the vehicle as a whole during high lateral accelerations. Most driver models are developed for low speed applications using linear control methods under the assumption of linear vehicle dy- namics. The dynamics of a vehicle however become highly non-linear as the lateral acceleration increases, thus rendering these linear models unusable during high speed manoeuvres. In this study, two robust driver models for use in an autonomous vehicle capable of path following at both low and high speeds are presented. Both models make use of the relationship between the yaw acceleration and steering rate to control the yaw angle of the vehicle. The first driver model is derived from the simulation of a full non-linear vehicle model in ADAMS. The Magic Tyre Formula is used to model the relationship between the vehicle's yaw acceleration and steer rate as a function of vehicle speed. The second driver model is a mathematical model which incorporates a form of sliding control. The model includes the lateral tyre dynamics as modelled by the Pacejka '89 tyre model. Both driver models are coupled with a gain scheduling proportional derivative controller to reduce the cross-track error. The two driver models were implemented on a Land Rover Defender and experimentally validated by performing a double lane change manoeuvre at speeds up to 80km/h. The vehicle remained stable even though the lateral accelerations experienced were 80% of the vehicle limits. The result is a robust controller capable of path following at various speeds and at high lateral accelerations. CopyrightDissertation (MEng)--University of Pretoria, 2011.
Mechanical and Aeronautical Engineering
Unrestricted
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Kung, Chun-Kai, and 孔俊凱. "Trajectory predictions and autonomous compensations for vehicle steering." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/59294779081428454491.
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Lakkad, Shailesh Hollis Patrick. "Modeling and simulation of steering systems for autonomous vehicles." 2004. http://etd.lib.fsu.edu/theses/available/etd-04112004-101215.
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Thesis (M.S.)--Florida State University, 2004.Advisor: Dr. Patrick Hollis, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed June 18, 2004). Includes bibliographical references.
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Kapp, Michael. "Robust High Speed Autonomous Steering of an Off-Road Vehicle." Diss., 2015. http://hdl.handle.net/2263/43784.
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A ground vehicle is a dynamic system containing many non-linear components, ranging from the non-linear engine response to the tyre-road interface. In pursuit of developing driver-assist systems for accident avoidance, as well as fully autonomous vehicles, the application of modern mechatronics systems to vehicles are widely investigated. Extensive work has been done in an attempt to model and control the lateral response of the vehicle system utilising a wide variety of conventional control and intelligent systems theory. The majority of driver models are however intended for low speed applications where the vehicle dynamics are fairly linear. This study proposes the use of adaptive control strategies as robust driver models capable of steering the vehicle without explicit knowledge of vehicle parameters. A Model Predictive Controller (MPC), self-tuning regulator and Linear Quadratic Self-Tuning Regulator (LQSTR) updated through the use of an Auto Regression with eXogenous input (ARX) model that describes the relation between the vehicle steering angle and yaw rate are considered as solutions. The strategies are evaluated by performing a double lane change in simulation using a validated full vehicle model in MSC ADAMS and comparing the maximum stable speed and lateral offset from the required path. It is found that all the adaptive controllers are able to successfully steer the vehicle through the manoeuvre with no prior knowledge of the vehicle parameters. An LQSTR proves to be the best adaptive strategy for driver model applications, delivering a stable response well into the non-linear tyre force regime. This controller is implemented on a fully instrumented Land Rover 110 of the Vehicle Dynamics Group at the University of Pretoria fitted with a semi-active spring-damper suspension that can be switched between two discrete setting representing opposite extremes of the desired response namely: ride mode (soft spring and low damping) and handling mode (stiff spring and high damping). The controller yields a stable response through a severe double lane change (DLC) up to the handling limit of the vehicle, safely completing the DLC at a maximum speed of 90 km/h all suspension configurations. The LQSTR also proves to be robust by following the same path for all suspension configurations through the manoeuvre for vehicle speeds up to 75 km/h. Validation is continued by successfully navigating the Gerotek dynamic handling track, as well as by performing a DLC manoeuvre on an off-road terrain. The study successfully developed and validated a driver model that is robust against variations in vehicle parameters and friction coefficients.Dissertation (MEng)--University of Pretoria, 2015.
Mechanical and Aeronautical Engineering
Unrestricted
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樊奕承. "Trajectory autonomous compensations for vehicle steering on four-wheel drive." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/59094918867885574215.
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Zhang, Zhi-hao, and 張志豪. "Trajectory Design and Tracking Control of Obstacle Avoidance for Autonomous Emergency Steering System." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8czjm7.
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碩士國立臺北科技大學
車輛工程系所
105
The maximum allowable lateral acceleration and jerk are used to plan the path for obstacle avoidance on both straight road and curved road. The geometry between the host vehicle and the front obstacle is used to calculate the last point to steer (LPS), which is used to trigger the autonomous emergency steering (AES) system. The path for obstacle avoidance is planned using the coordinate system of the host vehicle when the front obstacle is detected. The planned path is then transformed to be described using the coordinate system of the obstacle. The relative position and angle between the host vehicle and the obstacle are used for coordinate transformation during obstacle avoidance, such that the planned path can be obtained using the coordinate system of the host vehicle. The steering actuator dynamics is considered using a 5-state bicycle model while designing the tracking controller. A linear quadratic regulator (LQR) is employed to design the control law for tracking the planned path. The vehicle speed is employed for gain scheduling to reduce the computation load. CarSim/Simulink is used to evaluate the proposed approach. Preliminary simulation results show that the emergency obstacle avoidance at different speeds can achieved effectively on both straight and curved roads.
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Tan, Chiam Huat. "A simulation study of an autonomous steering system for on-road operation of automotive vehicles." Thesis, 1986. http://hdl.handle.net/10945/22104.
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Mu-ChengYu and 於睦程. "The Application of Fuzzy Control on the Anti-collision Steering of the Autonomous Underwater Vehicle." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/73308484573731793271.
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Hsu, Chien-Hsing, and 許健興. "A study of the active steering control on the driven wheel of an autonomous three-wheeler for limited turnings at low speeds." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/96303077407878918554.
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碩士國立中興大學
生物產業機電工程學系所
100
To reduce toeing out and the radius of gyration of a front wheel drive vehicle maneuvering through tight corners at low speeds, this thesis evaluated the dimensions of traction machines and designed the prototype of an autonomous three-wheeler with a four-bar equal-crank linkage steering mechanism for the front wheels and an active controlled driven rear wheel for overturning avoidance. The model of the synchronous gyration center of the wheels was proposed. A PID controller was then installed on the rear driven wheel with which allows the rear wheels to turn in the opposite direction when the front wheels are turning and results in a quicker and more efficient turning. The Freudenstein''s equation was employed to determine the optimal dimensions for the four-bar linkage mechanism of the prototype, too. The final results indicate that the radius of gyration of a three-wheeler set up with the theoretical dimensions, can be reduced by 19% to 29% and the undercutting of the rear wheels can also be prevented. Established and simulated on Solidworks, the proposed model was validated.