Dissertations / Theses on the topic 'Hydraulic control system'
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Kennedy, Joseph L. Fales Roger. "Force control of a hydraulic servo system." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/6582.
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The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on November 18, 2009). Thesis advisor: Dr. Roger Fales. Includes bibliographical references.
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Skjong, Stian. "Modeling, Simulation and Control of Hydraulic Winch System." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25578.
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In this thesis a hydraulic low pressure winch system has been modeled using bond graph theory. The hydraulic winch system is assumed to be installed on an offshore vessel affected by environmental forces and disturbances such as waves and currents. The hydraulic system powering the winch consists mainly of two pilot operated 3/3-directional valves controlled by two 4/3-directional valves and a hydraulic motor. The system also includes a pressure relief valve, check valves, pump systems, piping and filters. The 3/3-directional valves are the main focus in the model and are therefore modeled with less simplifications compared to the other subsystems. A thorough model study has been initiated to figure out the model limitations, sensitivity of model parameters and the ability to simplify the derived model without loosing essential dynamics and characteristics. The effects of variable bulk modulus and fluid inertia in the 3/3-directional valves have been studied by comparing different step responses and motor load characteristics. The observations and results from this model analysis laid the groundwork for control of the hydraulic motor. A clear relation between the main valve displacements and the motor velocity and torque in 4/3 valve configuration gave reasons to believe that manual motor control done by the winch operator through control of the valve displacements was possible. Adaptive PID controllers were used as inner controllers to control the control slides in the main valves. These controllers were later on replaced with PD-controllers when outer control was derived because the adaptive controllers tended to be a bit slow. Simplified state equations describing the motor dynamics were derived for control design purposes. The state equations extracted from the bond graph model showed high complexity, containing logic and discrete quantities, and were not suitable for control design. Model based speed- and torque controllers, based on sliding mode and backstepping control theory, were derived based on the simplified equations and implemented in the model. Different load cases were initiated to test the two controllers. A lumped wire-load model containing hydrodynamics, wire- and reel dynamics and environmental disturbances such as current and heave motions of the vessel were added in the total winch model to test the controllers in different operations with varying conditions and environments. The results from these controller tests gave reason to believe that a combination of these two controllers would be favourable in certain operations and would give increased safety in extreme cases such as stuck load and loss of load. The derived speed and torque controller were put into a hybrid controller framework and a switching algorithm was designed with focus on switching stability and wanted functionalities for the winch system. It was observed that switching stability and winch functionality were closely connected and different winch operations were essential in the design of the switching algorithm. Dwell time and tracking error switching were used as the main controller switching restrictions together with functionality based switching conditions. Different simulations were initiated to test the hybrid controller such as stuck load, loss of load and landing of a load at the sea floor. A Luenberger observer was derived to estimate the motor load and the motor velocity by using the simplified state equations and the differential pressure across the hydraulic motor as measurement in order to ensure redundancy in the control system and be able to control the hydraulic winch even though the decoder measuring the hydraulic motor velocity fails.
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Abdelgayed, Mohamed E. "Design and Control the Ancillary System for Hydraulic Hybrid Vehicle (HHV)." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1278075678.
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Hogan, Paul Anthony. "A knowledge-based system for automated fault analysis of hydraulic systems." Thesis, University of Bath, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332776.
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Reichenwallner, Christopher, and Daniel Wasborg. "Control of a Hydraulic Hybrid System for Wheel Loaders." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-158902.
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In recent years many companies have investigated the use of hybrid technology due to the potential of increasing the driveline’s efficiency and thus reducing fuel consumption. Previous studies show that hydraulic hybrid technology can be favourable to use in construction machinery such as wheel loaders, which often operate in repetitive drive cycles and have high transient power demands. Parallel as well as Series hybrid configurations are both found suitable for wheel loader applications as the hybrid configurations can decrease the dependency on the torque converter. This project has investigated a novel hydraulic hybrid concept which utilizes the wheel loaders auxiliary pump as a supplement to enable both Series and Parallel hybrid operation. Impact of accumulator sizes has also been investigated, for which smaller accumulator sizes resembles a hydrostatic transmission. The hybrid concept has been evaluated by developing a wheel loader simulation model and a control system based on a rule-based energy management strategy. Simulation results indicate improved energy efficiency of up to 18.80 % for the Combined hybrid. Moreover, the accumulator sizes prove to have less impact on the energy efficiency. A hybrid system with decreased accumulator sizes shows improved energy efficiency of up to 16.40 %.
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KRUTZ, JILL E. "DESIGN OF A HYDRAULIC ACTUATOR TEST STAND FOR NON-LINEAR ANALYSIS OF HYDRAULIC ACTUATOR SYSTEM." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin990813095.
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Votava, Marek. "Realizace řídicího systému pro hydraulický manipulátor." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228714.
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This diploma thesis concernes with the realization of a control system for hydraulic manipulator. It is devided into three main parts. The first part concerns sensors and actuators, which are used at the hydraulic manipulator. The second part describes design, production and programming of electronic control sub-system. The last part describes high level control software, created in the LabVIEW environment.
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Hochwallner, Martin. "On Motion Control of Linear Incremental Hydraulic Actuators." Doctoral thesis, Linköpings universitet, Industriell Produktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-142264.
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Linear Incremental Hydraulic Actuators combine one or more short-stroke cylinders, and two or more engaging/disengaging mechanisms into one actuator with long, medium, or even unlimited stroke length. The motion of each single short-stroke actuator concatenated by the engaging/disengaging mechanisms forms the motion of the linear incremental hydraulic actuator. The patterns of how these motions are concatenated form the gaits of a specific linear incremental hydraulic actuator. Linear incremental hydraulic actuators may have more than one gait. In an application, the gaits may be combined to achieve optimal performance at various operating points. The distinguishing characteristic of linear incremental hydraulic actuators is the incremental motion. The term incremental actuator is seen as analogous to the incremental versus absolute position sensor. Incremental actuators realize naturally relative positioning. Incremental motion means also that the behavior does not depend on an absolute position but only on the relative position within a cycle or step. Incremental actuators may realize discrete incremental or continuous incremental motion. Discrete incremental actuators can only approach discrete positions, whereby stepper drives are one prominent example. In contrast, continuous incremental actuators may approach any position. Linear electric motors are one example of continuous incremental actuators. The actuator has no inherent limitation in stroke length, as every step or cycle adds only to the state at the beginning of the step or cycle and does not depend on the absolute position. This led to the alternative working title Hydraulic Infinite Linear Actuator. Linear incremental hydraulic actuator provides long stroke, high force, and linear motion and has the potential to decrease the necessary resource usage, minimize environmental impact, e.g. from potential oil spillage, extend the range of feasible products: longer, stiffer, better, etc. This thesis presents an analysis of the characteristics and properties of linear incremental hydraulic actuators as well as the gaits and possible realizations of some gaits. The gait for continuous, smooth motion with two cylinders is comprehensively studied and a control concept for the tracking problem is proposed. The control concept encapsulates the complexity of the linear incremental hydraulic actuator so that an application does not have to deal with it. One other gait, the ballistic gait, which realizes fast, energy-efficient motion, enabling energy recuperation is studied.
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Roddis, Roge. "Evaluation of modern control system design techniques for a multivariable electro-hydraulic system." Thesis, Sheffield Hallam University, 2000. http://shura.shu.ac.uk/20288/.
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An experimental apparatus has been developed with the object of providing a test plant, based on commercially available electro-hydraulic components, for the investigation of multivariable control system design methodologies. A mathematical model has been produced for this experimental plant and a preliminary analysis of the plant carried out. A selection of controller design techniques has been investigated. Designs have been produced for two state feedback controllers in which the feedback coefficients were based on LQR theory, one of which used a full order estimator based on a Kalman Filter, the other using a reduced order observer whose poles were chosen arbitrarily. In addition, forward path compensators have been developed using the Characteristic Locus and the Hinfinity/Mixed Sensitivity methods. These controller designs were based on computations and simulations utilising Matlab and a selection of its control engineering toolboxes and Simulink. The completed designs were implemented in digital form and tested on the actual plant. A series of tests were carried out to assess the robustness of the various controllers in the presence of plant uncertainty. The physical plant was modified and the controllers based on the nominal plant model used in conjunction with this modified plant. As a design technique which enabled robustness issues to be addressed explicitly, the Hinfinity approach was used to improve the robustness of the original Hinfinity controller.
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Lu, C. "On-line self-optimisation of an electro-hydraulic servo control system." Thesis, University of Salford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381828.
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Pan, Min. "Active control of pressure pulsation in a switched inertance hydraulic system." Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558871.
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The nature of digital hydraulic systems may cause pressure pulsation problems. For example, switched inertance hydraulic systems (SIHS), which are applied to adjust or control flow and pressure by a means that does not rely on dissipation of power, have noise problems due to the pulsed nature of the flow. An effective method to reduce the pulsation is important to improve system performance and increase efficiency. Although passive systems to reduce the noise have been shown to be effective in many situations, their attenuation frequency range is limited and they may be bulky. Furthermore, attenuation devices based on expansion chambers, accumulators or hoses are likely to be unsuitable for SIHS as they add compliance to the system and would impair the dynamic response. This thesis is concerned with issues relating to the development of an active noise canceller for attenuating the pressure pulsation which is caused primarily by pulsed flow from high-speed valves in SIHS. Active control methods are widely and successfully applied in the area of structureborne noise (SBN) and air-borne noise (ABN) cancellation. The idea is using the intentional superposition of waves to create a destructive interference pattern such that a reduction of the unwanted noise occurs. However, applications for fluid-borne noise (FBN) attenuation based on the ‘Active noise control (ANC) principle’ are rare due to the restriction of the hardware and experimental apparatus in previous researches. In this thesis, an adaptive controller has been developed for active control of pressure pulsation in hydraulic system. The principle of the adaptive LMS filter and details of the controller design are described and the implementation was carried out through simulation. The designed controller was applied on a vibration test rig initially prior to the hydraulic testing in order to investigate its advantages and limitations in practice. Extensive testing on a switched inertance hydraulic rig proved that the controller, which used a piezoelectric valve with fast response and good bandwidth, is effective and that it has several advantages over previous methods, being effective for low frequency cancellation, with a quick response, and is robust and versatile. A novel method for the accurate measurement of unsteady flowrate in a pipe was proposed. This was applied and validated on a pipe, and was shown to give good results. This method solves the difficulty for measuring the unsteady flowrate currently by using easy-measured signals, such as pressures. It can be used widely for predicting the unsteady flowrate along the pipe.
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Wondimu, Nahom Abebe. "SIMULATED AND EXPERIMENTAL SLIDING MODE CONTROL OF A HYDRAULIC POSITIONING SYSTEM." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1145419922.
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Fahlén, Daniel, and Ludvig Fri. "Modelling and Control of a Forklift’s Hydraulic Lowering Function." Thesis, Linköpings universitet, Reglerteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139247.
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Material handling and logistics are fundamental parts of today’s global societyand forklifts are a crucial part of the material handling process. Making these asefficient and reliable as possible are therefore of great interest. In this master thesis, an effort has been made to improve the control of the hydraulic lowering function of a specific forklift. Today the lowering function iscontrolled through an open-loop control scheme making the control performancesensitive to disturbances and system changes. One disturbance of special interestis the temperature of the hydraulic fluid. The goal of this thesis was therefore todesign a controller with improved robustness as well as improved performance. To solve this a model-based control design approach was used and a nonlineargrey-box model was derived, implemented and validated. The model parameterswere estimated using a nonlinear least-squares optimisation problem. The resulting model captures most of the system dynamics and the model fit is higher than 70% which was deemed good enough to use for control design. A PID controller was designed based on the estimated model and the controllerparameters were optimised. Furthermore, the controller was evaluated in simulations and implemented in a real forklift. The proposed controller was compared to the original controller for various scenarios. The results reveal improvedsteady state behaviour with enhanced temperature robustness compared to theoriginal controller.Materialhantering och logistik är viktigt för att dagens globala samhälle ska fungera. En grundläggande del i materialhanteringsprocessen är gaffeltruckar, därför är det av intresse att göra gaffeltruckar så effektiva och pålitliga som möjligt. I det här examensarbetet har ett försök gjorts till att förbättra styrningen av den hydrauliska sänkningsfunktionen hos en specifik gaffeltruck. Dagens lösning använder sig av öppen styrning vilket gör reglerprestandan känslig för störningar och systemförändringar. En störning av extra intresse är temperaturen av hydraulvätskan. Målet med detta arbete var därför att designa en regulator med ökad robusthet och prestanda. För att lösa detta har en modellbaserad metod för regulatordesign använts där en olinjär gray-box modell härleddes, implementerades och validerades. Modellparametrarna skattades genom att ställa upp och lösa ett ickelinjärt minsta-kvadrat optimeringsproblem. Den resulterande modellen fångar det mesta av systemdynamiken och modellpassningen till uppmätt data var högre än 70\% vilket ansågs bra nog för att kunna använda modellen som en bas för regulatordesign. En PID regulator designades och regulatorparametrarna optimerades med hjälp av modellen. Regulatorn utvärderades i simuleringar och för att sedan implementeras den på en riktig gaffeltruck. Den föreslagna regulatorn jämfördes med den ursprungliga regulatorn i flera olika testfall. Resultaten visade ett bättre steady-state beteende och ökad robusthet mot temperaturförändringar för den designade regulatorn jämfört med den ursprungliga regulatorn.
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André, Simon. "Design and Optimization of Controllers for an Electro-Hydraulic System." Thesis, Linköpings universitet, Reglerteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-107620.
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Electro-Hydraulic (EH) systems are commonly used in the industry for applications that require high power-weight ratios and large driving forces. The EH system studied in this master thesis have recently been upgraded with new hardware components and as a part of this upgrade a new controller was requested. The system consists of a controller that computes a control signal for an electric motor. The motor drives a gear pump that generates a flow of hydraulic fluid. The flow is then directed to a cylinder. The movements of a piston in the cylinder is affected by the flow and the piston position can be measured. The measured piston position is then fed back to the controller and the control loop is complete. The system was previously controlled using a Proportional-Integral-Derivative (PID) controller and the purpose of this thesis is to compare the old controller with alternative control strategies suitable for this application. The evaluation of the controllers is based on both software and hardware simulations and results in a recommendation for final implementation of the best suited controller. The control strategies chosen for investigation are: a retuned PID controller, a PID controller with feed forward from reference, a PID based cascade controller, a Linear Quadratic (LQ) controller, and a Model Predictive Controller (MPC). To synthesize the controllers an approximate model of the system is formed and implemented in the software environment Matlab Simulink. The model is tuned to fit recorded data and provides a decent estimation of the actual system. The proposed control strategies are then simulated and evaluated in Simulink with the model posing as the real system. These simulations resulted in the elimination of the cascade controller as a possible candidate since it proved unstable for large steps in the reference signal. The remaining four controllers were all selected for simulation on the real hardware system. Unfortunately the MPC was never successfully implemented on the hardware due to some unknown compatibility error and hence eliminated as a possible candidate. The three remaining control strategies, PID, PID with feed forward from reference and the LQ controller, were all successfully implemented and simulated on hardware. The results from the hardware simulations compared to simulations made with the old controller, as well as the results from the software simulations, were then evaluated. Depending on the purpose one of two control strategies is recommended for this application. The LQ controller achieved the best overall performance and is presented as the control strategy best suited for this application.
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Zanhar, Andrej. "Modeling, Identification and Control Design for an Electro-Hydraulic Rotator." Thesis, Linköping University, Department of Electrical Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-54377.
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Robotic manipulators have been introduced in industry as a form of increasing productivity. Today, there exist an interest to enlarge the application of these manipulators to outdoor environments. Forestry cranes used in the forestry industry are a clear example. A long term goal in this industry is the development of autonomous systems to increase the logging efficiency. In this thesis, we consider how to control the rotator of these cranes, which is an electro-hydraulically actuated motor, and is used to control the end ffector tool. Control system design for the rotator is a challenging task since the sensing is not available to full extent. The main reason is the harsh environment that these machines are exposed to and sensors such as encoders are very fragile and cannot be used. In this thesis we use alternative sensing devices, such as a magnetic sensor and a stereo camera. In the case of the camera we face a problem with big delay. A prediction method has been used to compute desired values. Due to various reasons certain measuring devices can not be used in the industry. We consider four cases for control system design where dfferent combinations of available sensors have been used. Initially angular position of the rotator is controlled using only the magnetic sensor. A cascade control setup is used where pressure and position are measurable, first using the magnetic sensor and later using the camera. When only pressure measurements are available identified models have replaced sensors for position feedback. All tests and experiments have been done using a scaled version of a real forestry crane. The available crane has similar configuration and dynamics as the real one and is therefor useful for experimental purposes.
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Tsai, Chi-Keng. "Computer control of an electro-hydraulic robot leg with proximity ranging system /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487260135355525.
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Xu, Yaozhong. "Modelling and control of a high performance electro-hydraulic test bench." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00876661.
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Hydraulic systems are widely applied in industry for position or force control. However, due to hydraulic system nonlinearities, it is difficult to achieve a precise model valid over a large range of frequencies and movements. The work in this dissertation focuses on a high performance hydraulic test bench which involves three main hydraulic components, i.e. two high performance servovalves, a double rod actuator, and a specific intermediate block connecting the servovalves and actuator. This rig has been designed for testing aerospace or automotive components in real conditions (e.g. wear and ageing effects). The main objectives of this dissertation are first the development of a virtual prototype based on a precise model which is derived from the physical principles and experimental works, and then second the synthesis of several nonlinear control laws of this actuation system in a large operating range with a good robustness to the perturbations. The proposed model based on Bond Graph shows a very good agreement with experimental results not only at low frequencies, but also at high frequencies. Moreover, its performances are improved at high frequencies by introducing the dynamic effects due to the intermediate block. Besides, multivariable and monovariable control strategies, based on respectively the backstepping and the model-free method, are developed and implemented on the test bench. All the control strategies proposed have been validated by simulations and experiments. Results show they lead to better tracking precision and robustness performance compared to the conventional control techniques.
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Zhang, Boya. "Modeling and Analysis of Hydraulic Energy Storage System for Hybrid Locomotives." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1288815815.
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Gao, Lingchong, Boyang Shi, Michael Kleeberger, and Johannes Fottner. "Optimal control of the hydraulic actuated boom system based on port-hamiltonian formulation." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71119.
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The boom systems of mobile cranes and aerial platform vehicles are driven by hydraulic systems, to be specified, valve-controlled hydraulic cylinders. This hydraulic actuated boom system can accomplish the tasks such as lifting heavy loads or carrying personal to high position, by the design of a long boom structure. In practice, the boom structure is designed as light and slender as possible to control the structure self-weight. However, such structure is quite flexible and can be easily stimulated by the loads, including the driving force or torque from the hydraulic system. Our research focuses on trajectory planning for hydraulic actuated boom where both hydraulic driven system and boom structure deformation are considered. In this paper, the hydraulic actuated boom system is formulated as a port-Hamiltonian system which is a proper modelling method for multi-domain system. The problems of trajectory optimization and vibration control are formulated as optimal control problem based on port-Hamiltonian model and this procedure is tested on a model of hydraulic cylinder. A reasonable result is solved with the selected cost function and inputs.
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Escolano, Andrés Inés. "Knowledge-Based Flight Control System Integration in RAPID." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-113531.
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This thesis work presents a parametrized integration of the flight control system within RAPID by means of the automation in CATIA V5, using Knowledge Pattern. Nowadays aircraft’s design and development processes are not only time-consuming but also incur high economic cost. In addition, system integration is highly a multi-disciplinary design process which often involves a large number of different discipline teams working at the same time and space. The main objective of this thesis is to investigate how CAD (Computer Aided Design) software can be used in the early design stages to define the flight control system integration. The purpose of this work to improve the functionality of an in house produced aircraft conceptual design tool carried out at the Division of Fluid and Mechatronic Systems, Linköping University. The work consists of preliminary integration of the RAPID flight control system and the hydraulics associated to it. By defining several reusable templates, the automatic definition of a flight control system within the RAPID aircraft has been achieved. Moreover it is a parametrical model which allows the user to modify a high number of features as desired to enhance the design process. For this, a user interface in Microsoft Excel connected to CATIA has also been attained.
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KOWTA, SRINIVAS. "ROBUST STABILITY ANALYSIS OF SERVO-HYDRAULIC SYSTEM IN PARAMETER SPACE." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1060970575.
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Chiang, Mao-Hsiung, Yung-Ching Sung, and Han-Hsiang Liu. "A Study on Integration of Energy Harvesting System and Semi-Active Control for a Hydraulic Suspension System." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199913.
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Suspension systems are used to diminish the vibration of vehicles. The hydraulic dampers in conventional suspension systems are mainly designed with the orifices of the piston; however, the vibration energy will be transferred into waste heat. In recent years, conventional vehicles with internal combustion engines and hybrid vehicles are used commonly. However, with the gradual depletion of fossil fuels, electric vehicles are developing. For this reason, the research focuses on recycling energy from the suspension of vehicles to improve the vehicle’s endurance. The purpose of this study is to develop a semi-active suspension control system with an energy harvesting system. Instead of the fixed orifices in conventional vehicles, an adjusting damping force method with variable resistance circuits system is studied for the semi-active suspension control system. Thus, we are able to develop semi-active control to improve the riding comfort. The energy harvesting system contains a hydraulic gear motor and a DC generator. When vehicles vibrate, the hydraulic damper serves as a hydraulic pump to compress the oil and drive the hydraulic motor. At the same time, the hydraulic motor drives the generator to generate electricity which will be stored in a battery. In this study, the test rig is the quarter-car system. We first design the novel hydraulic suspension system combining with the energy harvesting system. The simulation of dynamic mathematical model will be performed and analyzed by MATLAB/Simulink. Besides that, the semiactive control by the fuzzy sliding mode controller will be realized in the hydraulic suspension system with energy harvesting system. Finally, a test rig is set up for practical experimental implementation and verification.
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Pomierski, Wojciech. "Position signal filtering for hydraulic active heave compensation system." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71095.
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In the paper a new position signal filtering method with position prediction is presented along with test results using a simulation tool. The complete active heave compensation system performance with input signal filtering is also shown. The control system uses an input acceleration signal taken from the motion reference unit, which usually contains noise that is not acceptable for the position controller. Currently, a Kalman filter is used which is okay to use for certain conditions. The filter works similarly to how it is used for autonomous applications where two input positions are necessary, one from position sensors and another one taken from the model. The challenge is that there is no physical wave model available for the Kalman filter used for offshore position control and the waves are not predictable. It was found that a Kalman filter with a special signal prediction instead of the model input can be used. This position prediction helps to avoid system delays and the potential of missing the signal for a short period of the time.
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Paterson, Alan Stanley. "The development of an expert system to facilitate the synthesis and analysis of hydraulic directional control valves." Thesis, De Montfort University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253485.
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Azolibe, Ifeanyi. "Architecture of a cyber-physical system for aircraft fuel control systems tests." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/8503/.
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The aircraft fuel control system makes sure an engine has the precise amount of fuel required to generate power and thrust for every stage of flight. It therefore plays a role in determining the economics of flight. In order to maintain the economic equilibrium of performance and flight safety, it undergoes a Maintenance Repair or Overhaul (MRO) service after several hours of operation. A critical aspect of the MRO service is the test performed to validate the airworthiness of a fuel control system before it returns to service. The test of aircraft fuel control systems is human-centric by design. The operator uses a network of test systems to generate in-flight conditions similar to what the Unit-Under-Test (UUT) experiences on-board an aircraft engine, then performs tests to validate and verify its airworthiness. Thereafter, test results are recorded for regulatory compliance reasons after each test is performed successfully. An analysis of the test specification for the UUT involved in this study revealed 90% of an operator’s touch-time is automatable. The functions of control, data processing, data entry and supervision must be achieved automatically if they are to be performed autonomously by a cyber-physical test system. But the automation of these activities at the micro level does not guarantee their autonomous execution at a macro level by such a cyber-physical system composed of the network of test systems. Therefore, knowledge of a multidisciplinary array of fundamental concepts and how they can be fused to execute the test of aircraft fuel control systems autonomously, have been developed as presented in this thesis. For the function of process control, the response of the processes used to set test conditions is ~ 50Hz, five times the rate of process responses reported in typical process industries where automation of process control have been achieved. As a result of this fundamental knowledge, the design of the architectures for the functions of control and data processing is an asynchronous one. Noting that none of the data is fed back through a network like the case of Networked Control Systems or Supervisory Control and Data Acquisition Systems. The realization of the control functions for each process used to set test conditions is based on control laws synthesized through modelling of their respective actuation mechanisms. Of the three models developed, a 2nd order model has been identified as been representative of the dynamic and steady-state characteristics of each actuation mechanism. A typical actuation mechanism contains a high number of masses and springs whose physical modelling resulted in a model of 12th order. This model is highly unrepresentative of the transient and steady-state response observed in the process due to difficulty in estimating the internal parameters of respective actuators. A linear model synthesized from the calibration data of each actuation mechanism has also been investigated and found to be too ideal. Its response is unrepresentative of the dynamic characteristics of the actuation mechanisms. The processes used to generate test conditions have been set simultaneously using a network of PID controllers. The controllers’ gains are an order of ten less than what they were for the sequential set up of test conditions due the fact that there are interactions between the processes inside a UUT. Fundamentally however, this Thesis demonstrates an asynchronous architecture for the control function, which enables a pseudo steady-state execution of tests. In-practice, this has the potential to reduce the time it takes to perform a test by one-third. The function of supervision has been developed in the form of a Fault Detection Isolation and Recovery capability within the cyber-physical test system. The architecture for this function is designed based on minimalizing the constraint of the period of recoverability (PoR), where the deviations from normal operation need to be detected, the outcomes they could result to—diagnosed and recovery strategies executed to prevent test systems or the UUT deviate from normal operation, using measurements acquired in a time < PoR. Oscillations and offsets have been identified as the major causes of deviations in subsystems during the test of the aircraft fuel control system in this study. In order to diagnose a deviation, a fuzzy inference engine has been developed over a Fault Tree Analysis approach because it makes the automation of domain knowledge needed to realize the supervision function effective. Nevertheless, the contributions of this thesis are the knowledge gaps it uncovers and the formalized approaches it proposes in the form of architectures to plug these gaps. It provides a direction on how to actualize not only the concept of automation, but the realization of a cyber-physical system to test an aircraft fuel control systems. It is the architecture of a singular system capable of executing the functions performed by an operator autonomously, and surpassing what can be achieved in the case of simultaneous process control, automated detection and isolation of a critical deviations under the period of recoverability, that is the fundamental contribution of this thesis. So that in the not so distant future the test of aircraft fuel control systems can be performed by machines.
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Koutecký, Vojtěch. "Hydraulický systém regulace vodní turbíny." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401001.
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The aim of this diploma thesis is to create a hydraulic system for water turbine control. The basic dimensioning of the hydraulic elements is included in order to build a functional hydraulic diagram.
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Wang, Meng (Rachel), Per Danzl, Vishal Mahulkar, Damrongrit (Neng) Piyabongkarn, and Paul Brenner. "A hydraulic test stand for demonstrating the operation of Eaton’s energy recovery system (ERS)." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199521.
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Fuel cost represents a significant operating expense for owners and fleet managers of hydraulic off-highway vehicles. Further, the upcoming Tier IV compliance for off-highway applications will create further expense for after-treatment and cooling. Solutions that help address these factors motivate fleet operators to consider and pursue more fuelefficient hydraulic energy recovery systems. Electrical hybridization schemes are typically complex, expensive, and often do not satisfy customer payback expectations. This paper presents a hydraulic energy recovery architecture to realize energy recovery and utilization through a hydraulic hydro-mechanical transformer. The proposed system can significantly reduce hydraulic metering losses and recover energy from multiple services. The transformer enables recovered energy to be stored in a high-pressure accumulator, maximizing energy density. It can also provide system power management, potentially allowing for engine downsizing. A hydraulic test stand is used in the development of the transformer system. The test stand is easily adaptable to simulate transformer operations on an excavator by enabling selected mode valves. The transformer’s basic operations include shaft speed control, pressure transformation control, and output flow control. This paper presents the test results of the transformer’s basic operations on the test stand, which will enable a transformer’s full function on an excavator.
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Aquaro, Matthew. "Systems engineering in practice : the application of systems engineering principles to the development of a hydraulic control system for an automatic transmission." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44701.
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Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2008.Includes bibliographical references (p. 71).
Product development in the automotive industry has evolved around the design of components. The organization is established around components and people have a very component centric perspective on problem solving. This has led to local optimization of individual components, while the larger system spirals out of control. The penalty is often measured in terms of development time and cost. New programs are given autonomy to make independent choices without regard for what other programs are doing, which leads to a wide variety of architectures put into place. Program managers and functional managers have different prioritizations. Furthermore, new designs are provided by a separate organization from the group responsible for implementation. They have a very different value system and are unaware of the difficulties experienced in the implementation phase. This type of practice leads to programs nearing production deadlines with poorly optimized systems. Engineers must relearn due to the lack of standardization across program. The team absorbs additional resources from within to fix issues prior to launch. The robbing of resources leads to delays in subsequent programs and the cycle repeats itself. These issues are partly cultural, part organizational, part due to lack of understanding of systems engineering. A new organization is designed, which strengthen the systems perspective and give power to a new role in the organization, the Systems Engineer. The Systems Engineer is chartered with global optimization of the entire system, which includes both functional aspects as well as business aspects like resource availability, development cost and time. They are responsible for developing the complete system, from concept to final implementation. The Design Structure Matrix (DSM) shows the boundaries of the system and reveals new areas where the Systems Engineer can influence the design at lower cost to the organization.
(cont.) The Robustness Checklist, standardization and Systems Architecture provide Systems Engineers tools to change from a component mindset to a systems mindset and to optimize the system as a whole.
by Matthew J. Aquaro.
S.M.
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Comella, Laura [Verfasser], and Thomas [Akademischer Betreuer] Bauernhansl. "Position sensor and control system for micro hydraulic drives in surgical instruments / Laura Comella ; Betreuer: Thomas Bauernhansl." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2019. http://d-nb.info/1206183993/34.
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Lammers, Zachary A. "Thermal Management of Electromechanical Actuation System for Aircraft Primary Flight Control Surfaces." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1399021324.
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Oliver, Danielle Simonette. "Power Requirements of Control Surface Actuators Towards Active Aeroelastic Control Using the Method of Receptances." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami159601703575348.
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Wamalwa, Fhazhil. "Optimal control of a conventional hydropower system with hydrokinetic/wind powered pumpback operation." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/61549.
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The need to ease pressure from the depleting fossil fuel reserves coupled with the rising global energy demand has seen a drastic increase in research and uptake of renewable energy sources in recent decades. Of the commonly exploited renewable energy resources, hydropower is currently the most popular resource accounting for 17% of the world's total energy generation, a portion which translates to 85% of the renewable energy share. However, despite the huge potential, hydropower is dependent on the availability of water resource, which is affected by climate change. During wet seasons, hydropower system operators are faced with a deluge of floods which results in excess power generation and spillage. The situation reverses in dry seasons where system operators are compelled to curtail power generation because of low water levels in the hydro reservoirs. The later situation is more pronounced in drought prone regions such as Southern Africa where some hydropower plants are completely shut down in dry seasons due to water shortage.
This dissertation focuses on the application of optimal control to hydropower plants with pumpback retrofits powered by on-site hydrokinetic and wind power systems. The first section of this work develops an optimal operation strategy for a high head hydropower plant retrofitted with hydrokinetic-powered cascaded pumpback system in dry season. The objective of pumpback operation is to recycle a part of the downstream discharged water back to the main dam to maintain a high water level required for optimal power generation. The problem is formulated as a discrete optimisation problem to simultaneously minimise the grid pumping energy demand, minimise the wear and tear associated with the switching frequency of the two pumps in cascade, maximise restoration of the reservoir volume through pumpback operation and maximise the use of on-site generated hydrokinetic power for pumping operation. Simulation results based on a practical case study show the pumping energy saving advantages of the cascaded pumping system as compared to a classical pumped storage (PS) system.
The second section of this work develops an optimal control system for assessing the effects of ecological flow constraints to the operation of a hydropower plant with a hydrokinetic-wind powered pumpback retrofit. The aim of the control law in this case is to use the allocated water to optimally meet the contractual obligations of the power plant. The problem is formulated as a discrete optimisation problem to maximise the energy output of the reservoir subject to some defined technical and hydrological constraints. In this system, pumping power is met primarily by the wind power generator output supplemented by the on-site generated hydrokinetic power. The excess hydrokinetic power is exported to the grid to meet the committed demand. Three different optimisation scenarios are developed: The first scenario is the baseline operation of the hydropower plant without any intervention. The second scenario incorporates the hydrokinetic-wind-powered pumpback operation in the optimal control policy. The third scenario includes the downstream flow constraint to the optimal control policy of the second optimisation scenario. Simulation results based on a practical case study show that ecological flow constraints have negative effects to the economic performance of a hydropower plant.Dissertation (MEng)--University of Pretoria, 2017.
MasterCard Foundation Scholars Program
Centre of New Energy Systems
University of Pretoria
Electrical, Electronic and Computer Engineering
MEng
Unrestricted
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Wang, Chi-Wei, and 王麒維. "Implementation of Hydraulic Servo Control System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/33627302981614219015.
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碩士國立高雄應用科技大學
機械與精密工程研究所
101
In this thesis, to stabilize the liquid pressure-controlled in a water cleaning system, planed and designed of a hydraulic servo control system. The control module is based on the microprocessor and planed PC Based the interface of transmission by RS232 to monitor the pressure value and calculated pressurizing pump differential pressure values and transmit control commands to the microprocessor then drive the servo motor to achieve the stable liquid pressure in a hydraulic servo control system. On the PC side, the design is based on the C# to do compare and correct between the target pressure value and servo motor speeds, while the design of the pressure regulator control method allows hydraulic servo control system can be done effectively stable pressure regulator controls the pressure of the entire system sensing component is the use of pressure transmitters, and pressure value is to capture by A/D card. In the simulation, the motion analyzing of a hydraulic servo control system motion based on PID and Fuzzy controller was done by MATLAB/SIMULINK software. On the experiment, we use C# to create a man-machine interface with the RS232 protocol to send control commands, while using pressure transmitters pass back and forth a hydraulic servo control system pressure values, In the hardware configuration, mainly including a pressurizing pump, serial unit, the power conversion unit, I/O hydraulic pressure sensors(transmitters), the DC motor drive unit(drive and speed control). In this thesis we have built a set of hydraulic servo control system presses by reaching a stability to control of purpose, at the same time letting to add to press system can ensure its clean water effect and stabilize water and add the service life of pressing the system. Rise the function of clean water system further because this system considers to add to press fluctuation and long term that the pressuring pump passes in and out water pressure to supervise and control at the same time, can also consequently reach the pipeline pressure of the hydraulic system variation supervision in addition.
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Cheng, Chih-Hsien, and 鄭志先. "Tracking Control of Electro-Hydraulic System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/83761902657725486395.
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碩士國立高雄應用科技大學
機械與精密工程研究所
97
This thesis presents the derivation, and simulation of a nonlinear tracking control for an electro-hydraulic system, as these devises must often follow prescribed motions. An analysis of nonlinear system equation is used in the derivation of a singular perturbed function that provides for exponentially stable force trajectory tracking. This control law is extended to provide position tracking, and employed hydraulic fluid bulk modulus a difficult to characterize quantity as a parameter. To overcome the difficulty, we have developed a controller design procedure that required no additional sensors, and is robust to variations in the bulk modulus. A dual approach of singular perturbation theory and Lyapunov techniques from the basis for the procedure. The simulation results show that the proposed derivation singular perturbed function and controller design will track a given smooth trajectory with small error.
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Chiang, Yu-Lun, and 江宇倫. "Modeling and control of hydraulic linear platform and hydraulic adjustment system." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8bpa2v.
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Lai, Chien-Pang, and 賴建邦. "Circuit Realization and Control of Electro-Hydraulic Servo System in Hydraulic Punch." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/rs8dbu.
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碩士國立勤益科技大學
電機工程系
105
In this paper, the dynamics and control of an electro-hydraulic servo system for a hydraulic press are studied, including modeling, data analysis, optimization of proportional-integral-derivative (PID) control and sliding model control (SMC) and circuit implementation. The electro-hydraulic servo system inside a hydraulic press turns into a nonlinear and unstable system when affected by the nonlinear friction force. In this paper, the system’s motion behaviors are studied through theoretical derivation, modeling and data analysis. Particle swarm optimization (PSO) is also used to determine the optimized PID control parameters that further help control and stabilize the system. Another control method, SMC, is used for comparison. Experimental results indicate that the system can be controlled and its stable periodic motion can be maintained with each of PID and SMC control methods. Finally, the system is implemented with circuit design to verify the feasibility of the experiment, which can be used as reference for future study on an electro-hydraulic servo system for a hydraulic press.
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Cheng, Tseng Wei, and 曾偉誠. "The Iterative Learning Control of Hydraulic Cylinder Position Control System." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/19274669396940449270.
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碩士大葉大學
機械工程研究所
89
The iterative learning control (ILC) learns the unknown information from repeated control operation and can be used as the modification experience for the future control. Hence, ILC controller can make the system tracking error converge to a small region within a limited number of learning trials. This thesis considers the position control problem of a single-rod hydraulic cylinder with proportional valve. We derive its nonlinear mathematical model. However, the accurate system parameters are not easy to find and can''t be used for the controller design directly. Therefore in this study, we use system identification method to estimate the linear system model, and use two-dimensional theory to design ILC controller for the position tracking control of the hydraulic cylinder. We used PID controller and ILC controller in the computer simulation and experiment implementation. The results are analyzed and compared for each controller. Experimental results indicate that ILC controller can effectively handle repetitive trajectory tracking problem, especially in transient response that traditional control method can''t appropriate solve. Therefore, in this application, the control performance of ILC is better than the traditional PID controller.
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包志強. "Variable structure control of a hydraulic leveling system." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/88980117145632021949.
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Hamzehlouia, Sina. "MODELING AND CONTROL OF HYDRAULIC WIND ENERGY TRANSFERS." 2012. http://hdl.handle.net/1805/3365.
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Indiana University-Purdue University Indianapolis (IUPUI)The harvested energy of wind can be transferred to the generators either through a gearbox or through an intermediate medium such as hydraulic fluids. In this method, high-pressure hydraulic fluids are utilized to collect the energy of single or multiple wind turbines and transfer it to a central generation unit. In this unit, the mechanical energy of the hydraulic fluid is transformed into electric energy. The prime mover of hydraulic energy transfer unit, the wind turbine, experiences the intermittent characteristics of wind. This energy variation imposes fluctuations on generator outputs and drifts their angular velocity from desired frequencies. Nonlinearities exist in hydraulic wind power transfer and are originated from discrete elements such as check valves, proportional and directional valves, and leakage factors of hydraulic pumps and motors. A thorough understanding of hydraulic wind energy transfer system requires mathematical expression of the system. This can also be used to analyze, design, and predict the behavior of large-scale hydraulic-interconnected wind power plants. This thesis introduces the mathematical modeling and controls of the hydraulic wind energy transfer system. The obtained models of hydraulic energy transfer system are experimentally validated with the results from a prototype. This research is classified into three categories. 1) A complete mathematical model of the hydraulic energy transfer system is illustrated in both ordinary differential equations and state-space representation. 2) An experimental prototype of the energy transfer system is built and used to study the behavior of the system in different operating configurations, and 3) Controllers are designed to address the problems associated with the wind speed fluctuation and reference angular velocity tracking. The mathematical models of hydraulic energy transfer system are also validated with the simulation results from a SimHydraulics Toolbox of MATLAB/Simulink®. The models are also compared with the experimental data from the system prototype. The models provided in this thesis do consider the improved assessment of the hydraulic system operation and efficiency analysis for industrial level wind power application.
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Tsai, Chung-Pin, and 蔡崇彬. "Servo-hydraulic cylinder position control system using neuro- fuzzy control method." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/57005291642867179035.
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Hsing-YuChen and 陳星佑. "Hydraulic Control System Design for Unmanned Ultra-Light (UUL)." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/38116529483300998496.
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碩士國立成功大學
航空太空工程學系碩博士班
101
The research and application of an UAV has become more and more widely nowadays. An UAV is generally designed to accomplish certain tasks. However, due to the demand of an UAV with high payload and performance demand, converting an ultra-light aircraft into an UAV is the most feasible and possible way to meet this requirement. This thesis focuses on the design and verification of the unmanned ultra-light hydraulic controlling system. The main problem on voltage stabilization, feedback signal processing and hydraulic valves control are discussed, and solved by including their proportional relationship and reference voltage. All the control programs and electric circuits are integrated into a control board for flight tests. The UUL flight control is finally completely verified with its control capability and maneuverability in flight performance tests.
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Hu, Zong-Han, and 胡宗漢. "A Study of Hydraulic System for ProportionalCutter-height Control." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/16050300509390848844.
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碩士國立臺灣大學
生物產業機電工程學研究所
97
The purpose of this study is to develop an automatic control system for the cutter-height adjustment of tea pluckers. Using Automation Studio design software, the proportional control hydraulic system was simulated on the computer. The characteristics needed by the system were discovered and the feasibility of the system was tested by the simulation. A hydraulic device with a proportional valve was used for the position control. An ultrasonic sensor was also mounted on the system to detect the distance between the cutter on the plucker and the testing surface, like tea tree. A human-machine interface was built using software called Visual Basic 6.0. This interface used a RS-232 port and could receive data from an ultrasonic sensor (SRF05), Then the commands, were be sent to a proportional amplifier through a Multifunction Module called USB-4711. To establish a feedback control system, a personal computer, a proportional control hydraulic system, an A/D and D/A converter and an ultrasonic sensor were combined in this study. The system had accurate dynamic responses to the steady states by the tests with unit-step and square-wave signals. After the experiments with the ultrasonic sensor in the field, this system showed a good height tracing ability.
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Wang, Shau-Wei, and 王紹維. "The Compound Controller of Hydraulic Cylinder Position Control System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/46421650341350114211.
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碩士龍華科技大學
機械系碩士班
91
In general, a single-rod hydraulic servo system always has some characteristics such as high-degree, nonlinearity, time-variant and asymmetry. It is so difficult to calculate the mathematic model that is not easy to implement the position control of hydraulic servo system by using classical control. To work out a solution, adaptive control has the advantage of on-line tuning the control parameter to achieve a satisfactory performance. In the past research, the neural network rule is used to describe the dynamics of nonlinear systems widely, however, the drawback of slow convergence limits its application. Fast convergence speed of the parameter estimation have been guaranteed because each parameter has its own varying-gain for RLS. In this paper, the compound control algorithm of combining adaptive control, RLS and SNN is proposed for the position control application of a single-rod hydraulic servo system. In the transient state, to use RLS has rapid convergence to advantage. The control parameters can be approximately estimated and converged shortly for transient response. In the steady state, switching to use SNN rule makes the control parameter estimation asymptotically tend to true value and efficiently overcome its asymmetries. Finally, the result shows that the performance of compound control is superior to SNN control for transient and steady state. In addition, the compound control has a good stability in both of gain margin and phase margin.
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Lo, Wei-Chi, and 羅偉吉. "Application of Adaptive Hybrid Control for Adymmetric Hydraulic Servo System." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/01958157218124065321.
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碩士龍華科技大學
機械系碩士班
93
Hydraulic devices have been utilized in the industry extensively. It can provide features on production and modernization for the machinery. In general, close loop control within hydraulic servo system, it contains several instabilities such as high-degree, nonlinearity, time-variant and asymmetry; therefore, mathematical model and location control are not easily established by the conventional controller. With consistent developing on adaptive control theories, those instabilities have been resolved gradually from the last decade. Recently, adaptive control is capable of on-line tuning for control parameters in order to achieve performing satisfaction. In this study, adaptive control theorem has been implemented within close loop control for the hydraulic device incorporating with Lyapunov’s stability theorem and Normalized Algorithms into an integrated adjustable type of adaptive switch. With these initiating achievements on the switch, discuss its own advantages and disadvantages then make comparison between Lyapunov’s stability theorem and Normalized Algorithms.
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Cheng, Tun-Jen, and 鄭敦仁. "Neural Network Self-Tuning PID Control For Hydraulic Servo System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/30272423125943887059.
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碩士東南科技大學
機電整合研究所
99
The high performance electro-hydraulic servo systems (EHSV) need be applied to modern industry. The modern requirements of parameters variations and operation conditions variations become the new challenges for convention PID controls, which have used to be applied to electro-hydraulic servo systems. This paper is concerned with a new architecture of a self-tuning neural-PID control system and its application to control the displacement of an electro hydraulic servo system. This study proposed the three layers back propagation network to auto tuning the parameters of a conventional PID controller. The cylinder displacement of EHSV investigated by simulations, and simulation results reveal the proposed method is available for the EHSV system, and the appropriate PID control parameters can be on-line tuning by the proposed neural networks.
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Lin, Fangcheng, and 林芳正. "Investigations of Control system and Thermal-Hydraulic modeling in PCTRAN." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/56601177843256355459.
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碩士國立清華大學
工程與系統科學系
91
ABSTRACTS PCTRAN is a reactor transient and accident simulation software program that operates on a personal computer. It was developed by Taiwan Power Company and Micro-Simulation Technology (MST). PCTRAN have high resolution color display and interactive control capability enable versatile, high speed simulation, yet low cost transient simulation. We can use it to simulate various transients and events in order to assess the safety of nuclear power plants. In the present thesis, we will descriptive all of the PCTRAN model structure that it is include source code, VB interface and the data base structure correlation. We also detail investigations into PCTRAN system control blocks. Due to the fact that PCTRAN can not include all of the plant systems and transient initiation events, the operator should be familiar with plant basics in order to complete a reasonable and logical PCTRAN simulation run with its built-in existing functions. Under current basic PCTRAN structures, we can add or modify necessary VB objects and source codes to develop a proper tool for transient analysis in a nuclear power plant.
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Heyns, Louis Jacobus. "Describing function-based control synthesis for a nonlinear hydraulic drive system." Thesis, 2014. http://hdl.handle.net/10210/9688.
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M.Ing.Experimental tests have indicated that limit cycles are likely to occur in hydraulic drive systems, where backlash in the actuator seals is the dominant nonlinearity'. This study primarily deals with the analysis and synthesis of existing hydraulic drive systems to eliminate limit cycles and with establishing a design tool for the design of hydraulic drives with the object of avoiding limit cycles. Most analytical results were verified experimentally. The most general methods for the design of practical nonlinear systems are discussed. It is concluded that some form of synthesis and analysis is necessary, and that the need exists for general methods to evaluate the stability of nonlinear systems and design tools for nonlinear system design. Ageneral procedure of system analysis is given. Amathematical model of the system needs to be obtained, which can be done with the aid of bond graphs. Simulations of complex systems are recommended to verify system performance only. The first procedure of system analysis that should be followed is to systematically identify elements of the system which are not related to the cause of the limit cycle. Experimental testing is a good first step in identifying the non-critical elements. Signal flow diagrams enable the engineer quickly to determine all feedback loops of a complicated system which might be critical. Block diagrams are necessary for the application of nonlinear analysis and synthesis techniques. Hydraulic resonance, where the actuator seal acts as an oscillating mechanism, is identified as a possible cause of the limit cycle. An unusual application of the describing function, where the describing function is applied to optimize the hydraulic supply, is discussed. The transfer function of flow in a hydraulic pipe is given. With the use of the describing function, the gain margin can be studied versus different parameters of the plant. This gives insight into slightly damped conditions of the hydraulic supply that might be the cause of a limit cycle in the system. A control gain does not change the dynamic behaviour of the hydraulic supply, but only amplifies certain natural modes of the system. The design application of the describing function to nonlinear hydraulic drives is discussed. Procedures to eliminate an existing limit cycle and to design a nonlinear hydraulic drive system are proposed. Most important of all, is to design the system so that the natural frequencies of the mechanical structure and the hydraulic supply do not have any common multiples.
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KE, NAIN-PING, and 柯念平. "The application of model reference adaptive control to a solenoid valve control hydraulic system." Thesis, 1986. http://ndltd.ncl.edu.tw/handle/07506625624831936797.
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Xu, Kang. "Thermal and hydraulic modeling and control of a district heating system." Thesis, 2012. http://spectrum.library.concordia.ca/975015/1/Xu_MASc_S2013.pdf.
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A district heating system is a centralized heating system widely used for space heating. They offer economic benefits and are acknowledged to be more energy efficient. Their energy efficiency can be further improved by optimally controlling and operating the overall system. With this as the motivation a thermal and hydraulic model of a district heating is developed in this thesis.
The developed model consists of a boiler, six buildings, hot water distribution network, circulating pump, balancing and control valves and terminal heaters. Both dynamic and steady state hydraulic simulations were made to study supply, return water and zone temperature response; Pressure distribution in the piping network under different load conditions. A relationship between balance valve settings and outdoor temperature (heating load) was determined. It was shown that proper setting of balance valves as a function of heating load improves energy efficiency.
PI controllers were designed for the boiler and zone temperature control. Closed loop simulations are presented to show the control performance. By using steady state optimization technique optimal set points for the boiler temperature and near-optimal balance valve positions as a function of outdoor temperature were determined.
Simulation results show that the use of optimal set points and balance valve settings up to 20% energy can be saved compared to the conventional outdoor air reset control strategy. Simulation results under operating conditions are presented.
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JIANG, JIH-KAI, and 江繼開. "A Study on Hydraulic Servo Position Control System with Hybrid Controller." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/11719570726680477222.
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碩士逢甲大學
自動控制工程所
92
It is difficult to achieve efficient control time variable and nonlinear hydraulic system with conventional PID controllers. A novel fuzzy PID controller and a fuzzy logic parameter regulator are presented in this paper for design and apply to plant of position control. The emphasis is mainly on the tracking performance. For such a reason, an advanced method to improve the tracking accuracy with low pass filter. In general, the actual electro-hydraulic servomechanism will usually have an unavoidable operating delay time in the solid valve. This may sometimes cause close-loop instability if it was not treated carefully in the control system designs. Therefore, in the proposed control system, an adaptable wavelet network compensator used to compensate for the reduced time delay. In order to realize the proposed design and to evaluate the performance in practical applications, there is construct NI LabVIEW and DAQ card for a high-speed simulation platform with real-time capability. The SIMULINK simulation environment accompanied by LabVIEW Simulation Interface Toolkit（SIT）software package will used as a simulation platform on which a plant under controlled is constructed. Both simulation and experimental results are provided to show the effectiveness of the proposed method. .