Show simple item record

dc.contributor.supervisor Sepehri, Nariman (Mechanical Engineering) en_US
dc.contributor.author Maddahi, Ali
dc.date.accessioned 2019-03-06T21:47:42Z
dc.date.available 2019-03-06T21:47:42Z
dc.date.issued 2019-02-27 en_US
dc.date.submitted 2019-02-28T03:14:52Z en
dc.identifier.uri http://hdl.handle.net/1993/33781
dc.description.abstract Hydraulic actuators are used extensively in various equipment including aircraft, robots and heavy-duty machinery. One of the common problems in hydraulic systems is occurrence of faults such as the actuator internal leakage. Some faults need to be detected properly to prevent actuator malfunctioning. For example, the internal leakage deteriorates the system performance as it causes the fluid to move between cylinder chambers. Model-based fault detection techniques require a model of the hydraulic actuator and faults or an estimation of system parameters. In practice, there is no accurate model to describe some faults. Application of data-driven fault detection techniques is more desirable. One of the main challenges, due to the faults, in hydraulic actuation systems is the controller design. If a controller is not able to compensate for fault effects, it may lead to considerable losses. Therefore, there is a need for designing fault-tolerant controllers (FTCs). Data-driven techniques of controller design are good solutions to overcome challenges associated with obtaining models or estimating system and fault parameters. In this thesis, the applications of data-driven techniques of the fault detection and controller design to the hydraulic actuators are investigated and exemplified with detection of the internal leakage fault and design of a control system tolerant to the leakage. First, a set of multiscale measures is quantified in various healthy and faulty operating modes and a comparison is carried out, between the measures, to identify the most reliable indicator(s) in detecting various levels of the leakage. Comparison results indicate that the wavelet transform is the best technique, amongst the employed multiscale measures, for the internal leakage detection. Next, a fractional-order PID (FOPID) position controller is designed using experimental data. Efficacy of the designed controller in tracking various reference inputs, in presence of different system uncertainties, is examined through experiments. Finally, a methodology is developed for designing an FOPID-based FTC that does not require a prior knowledge about the model and parameters of the system and fault or emulation of the fault in experimental setup. The methodology is based on introduction of a set of synthetic errors to the hydraulic actuator. Experimental results prove that the methodology works well for a hydraulic actuator experiencing the internal leakage. en_US
dc.subject Fault-tolerant control en_US
dc.subject Robust control en_US
dc.subject Fractional-order PID controller en_US
dc.subject Multiscale analysis en_US
dc.subject Iterative feedback tuning en_US
dc.subject Hydraulic actuators en_US
dc.subject Fault detection en_US
dc.subject Wavelet transform en_US
dc.subject Fractal dimensions en_US
dc.subject Internal leakage detection en_US
dc.title Fault-tolerant control of hydraulically-powered actuators using fractional-order PID schemes en_US
dc.degree.discipline Mechanical Engineering en_US
dc.contributor.examiningcommittee Balakrishnan, Subramaniam (Mechanical Engineering) Kinsner, Witold (Electrical and Computer Engineering) Zhao, Qing (Electrical and Computer Engineering, University of Alberta) en_US
dc.degree.level Doctor of Philosophy (Ph.D.) en_US
dc.description.note May 2019 en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

View Statistics