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dc.contributor.supervisor Sepehri, Nariman (Mechanical Engineering) en_US
dc.contributor.author Rafiq, Moosa
dc.date.accessioned 2018-02-14T19:44:12Z
dc.date.available 2018-02-14T19:44:12Z
dc.date.issued 2018
dc.identifier.uri http://hdl.handle.net/1993/32886
dc.description.abstract Pump-controlled hydraulic actuation of single-rod actuators is more challenging than double-rod actuators due to difference in areas on two sides of single-rod actuators and a need to compensate for differential flow. The performance of a single-rod pump-controlled hydraulic circuit can be significantly affected by variations in load, velocity and circuit design. Designing a simple-to-implement velocity controller for such hydraulic configurations is challenging under these conditions. This thesis presents velocity control of two typical hydraulic circuits; one is commonly used while the other is a novel design. Two issues involved are controller design and component sizing. The design of velocity controllers is based on Quantitative Feedback Theory (QFT) as the design criteria are graphically illustrated for whole range of plant uncertainties in this design procedure. In order to design QFT controllers for closed-loop velocity control of pump-controlled single-rod hydraulic actuators, smooth open loop performance of hydraulic circuit becomes important. Hence component sizing, i.e., choosing optimal hydraulic components and having an optimal hydraulic design becomes necessary. Hence, a methodology to choose hydraulic components and hence improve system performance is proposed. First, a mathematical model of hydraulic circuit is developed, which is later used in simulations. Next, initial values of selected parameters of circuit components (pilot operated check valves and counterbalance valves) to be used in system are chosen based on manufacturer’s specifications, experimental data and conservative judgement. This is followed by choosing few parameters which need to be optimised. Next, an optimisation algorithm is used on the simulation model to optimize parameters chosen based on an optimization criteria. In optimization, particle swarm optimization (PSO) and modified Nelder-Mead (MNM) algorithms are used to obtain smooth, least jerky system performance. Next QFT Controllers are designed based on uncertainties found where families of transfer functions are to be obtained. For this purpose, system identification is used in order to obtain frequency responses from measured data and hence uncertainties. All the development reported in this research is experimentally validated. First hydraulic circuit is a commonly used circuit incorporating pilot-operated check valves, while as the second novel circuit uses counterbalance valves. en_US
dc.subject Hydraulic circuit en_US
dc.subject Optimization en_US
dc.subject Optimisation en_US
dc.subject Parameter en_US
dc.subject Control en_US
dc.subject Pilot operated check valve en_US
dc.subject Counterbalance valve en_US
dc.subject Valve en_US
dc.subject PSO en_US
dc.subject MNM en_US
dc.subject Nelder en_US
dc.subject Ten parameters en_US
dc.subject Hydrostatic en_US
dc.subject Pump en_US
dc.subject Pump Control en_US
dc.subject Algorithm en_US
dc.subject Simulation en_US
dc.subject Experiment en_US
dc.subject Cracking pressure en_US
dc.subject Optimal en_US
dc.subject Novel en_US
dc.subject Design en_US
dc.subject Methodology en_US
dc.subject Criteria en_US
dc.subject Particle en_US
dc.subject Swarm en_US
dc.subject Hydraulic design en_US
dc.subject Optimal design en_US
dc.subject Validation en_US
dc.subject Component sizing en_US
dc.subject Sizing en_US
dc.subject Sizing hydraulic circuits en_US
dc.subject Monika en_US
dc.subject Vibrations en_US
dc.subject Undesirable region en_US
dc.subject Multistep en_US
dc.subject Multistep polynomial en_US
dc.subject Single rod en_US
dc.subject Double rod en_US
dc.subject Single-rod en_US
dc.subject Double-rod en_US
dc.subject QFT en_US
dc.subject Quantitative Feedback Theory en_US
dc.subject Velocity control en_US
dc.subject Velocity en_US
dc.subject Component en_US
dc.subject Hydraulic component en_US
dc.subject Jerk en_US
dc.subject Objective en_US
dc.subject Objective function en_US
dc.subject ten parameter en_US
dc.subject Quadrants en_US
dc.subject System identification en_US
dc.subject Chirp en_US
dc.subject Chirp signal en_US
dc.subject Transfer function en_US
dc.subject Uncertainities en_US
dc.subject Feedback en_US
dc.subject Frequency en_US
dc.subject Gain margin en_US
dc.subject Phase margin en_US
dc.title Velocity control of single-rod hydrostatic actuators: component sizing and controller design en_US
dc.degree.discipline Mechanical Engineering en_US
dc.contributor.examiningcommittee Peng, Qingjin (Mechanical Engineering) Annakkage, Udaya (Electrical and Computer Engineering) en_US
dc.degree.level Master of Science (M.Sc.) en_US
dc.description.note May 2018 en_US


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