Show simple item record

FieldValueLanguage
dc.contributor.authorXie, Zhicheng
dc.date.accessioned2019-09-06
dc.date.available2019-09-06
dc.date.issued2019-02-28
dc.identifier.urihttp://hdl.handle.net/2123/21037
dc.description.abstractSpace manipulators could promote space exploration by assisting astronauts in space missions. Hence, controlling and modelling for space manipulators has been attracting research interest. However, the control of space manipulators presents challenges because of the coupling dynamics effects, the uncertain parameters and unknown disturbances. In this thesis, 2 types of adaptive sliding mode controller able to handle the uncertainties are designed to control the motions of both the manipulator’s joints and the spacecraft base. A radius basic function neural network–based less chattering sliding mode controller (NNLSMC) is designed. The neural network is used to approximate the lumped effects of uncertainties. The adaptive law of switching gain is positively proportional to the absolute value of sliding variables to achieve the convergence of sliding variables, while the adaptive law switches to the designed tangent function to decrease the chattering effects once the sliding variables move into the vicinity. The controller demonstrates the ability to mitigate chattering effects without the loss of robustness. However, the NNLSMC indicates the possibility of decreasing accuracy. Although the loss of accuracy can be mitigated by appropriately setting the parameters of adaptive law, it is laborious to manually tune those parameters. Thus, a reinforcement learning–based adaptive sliding mode controller (RLFSMC) is proposed, which has a similar problem to NNLSMC (mitigation of chattering effects, yet loss of accuracy). However, the exact parameters of the adaptive law are determined by the fuzzy logic inference, in which the fuzzy rules are automatically determined by modified reinforcement Q learning. Therefore, RLFSMC is less labour intensive and has greater potential to find better parameters than does the NNLSMC.en_AU
dc.publisherUniversity of Sydneyen_AU
dc.publisherFaculty of Engineeringen_AU
dc.publisherSchool of Aerospace, Mechanical & Mechatronic Engineeringen_AU
dc.rightsThe author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission.en_AU
dc.titleDynamics Modelling and Sliding Mode Control Design with Less Chattering Effect for Free-Flying Space Manipulatoren_AU
dc.typeMasters Thesisen_AU
dc.type.pubtypeMaster of Philosophy M.Philen_AU
dc.description.disclaimerAccess is restricted to staff and students of the University of Sydney . UniKey credentials are required. Non university access may be obtained by visiting the University of Sydney Library.en_AU


Show simple item record

Associated file/s

Associated collections

Show simple item record

There are no previous versions of the item available.