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Abstract:
Background Since there is a dynamic coupling effect between the space manipulator and the base, the motion of the space manipulator will inevitably lead to the elastic vibration of the base. Due to the thin air and extreme environment in the space, the elastic vibration of the base decays slowly and the actuator is prone to the failure of efficiency loss, which will severely decrease the tracking accuracy and stability of the space robot. In addition, considering the design tolerances, installation deviations and frictions, the inertial parameters of the system are uncertain, which will also affect the control effect of the actuator. This research is dedicated to achieving high-accuracy and high-stability control of the elastic space robot with actuator faults and uncertain dynamics. Methods According to the linear momentum conservation law, the Langrangian dynamics equation of the system is established. Based on the singular perturbation theory, the dynamic model is decomposed into a slow-varying subsystem denoting the trajectory tracking motions of the base attitude and the joints and a fast-varying one denoting the nonlinear vibration of the elastic base. A hybrid controller consisted of a decentralized neural network fault-tolerant controller of the slow-varying subsystem and a proportion differentiation (PD) feedback controller of the fast-varying subsystem is formulated. Conclusions The neural network fault-tolerant controller of the slow-varying subsystem can compensate the unknown actuator faults and uncertain dynamics and obtain H infinity convergence performance, while the PD feedback controller of the fast-varying subsystem can damp out the residual vibration of the elastic base. Simulation results confirm the feasibility and effectiveness of the hybrid control strategy.
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JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES
ISSN: 2523-3920
Year: 2021
Issue: 8
Volume: 9
Page: 2121-2131
2 . 3 3 3
JCR@2021
2 . 1 0 0
JCR@2023
ESI Discipline: ENGINEERING;
ESI HC Threshold:105
JCR Journal Grade:3
CAS Journal Grade:4
Cited Count:
WoS CC Cited Count: 4
SCOPUS Cited Count: 6
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 2
Affiliated Colleges: