Adaptive Fault-Tolerant Control for Flexible Manipulators Multiagent Systems With Unknown Dead-Zones Under Switching Topology
Wei Zhao, Hao Sun, Zhijia Zhao, Yu Liu
Abstract
For multiple flexible manipulator systems under an undirected switching topology graph with actuator faults, dead zones, and external disturbances, the proposed distributed control technique aims to attain joint angle consensus and vibration suppression. Therefore, in boundary controller design, the Nussbaum function is utilized to address the issue of uncertain control direction caused by fault tolerance and dead zones. Then, under the condition that the switching topology is connected, by using the backstepping technique, a new Lyapunov function is introduced so that the multiple flexible manipulators system can ensure angle cooperative control and vibration suppression while not knowing the control direction. Moreover, the adaptive law is designed to handle compound disturbances consisting of the unknown dead zones, additive faults, and boundary disturbances. Furthermore, we show that the flexible manipulator system is uniformly ultimately bounded and stable according to the Lyapunov stability theory. Ultimately, through the numerical simulation, the control strategy’s efficacy is confirmed.