Multi-model switching-based fault tolerant control for planar robot manipulators

This study addresses the fault-tolerant tracking control issue for a class of planar manipulators with various actuator and sensor faults. Firstly, a set of linear models are constructed to approximate the original non-linear model at the different joint angular positions, which explicitly reveal the coupling effects among sub-manipulators. Secondly, a family of decentralised fault-tolerant controllers are proposed with each one being related to one linear model respectively, which does not require the information exchange among sub-manipulators and thus lightens the communication burden. Finally, a switching law is proposed among controllers such that the system remains stable in the presence of controller switching. An example of a three-link planar robot manipulator is taken to illustrate the effectiveness of the proposed methods.