State observer – based finite-time fault tolerant control of single-joint robotic arm with command filtered and event-triggered techniques

This article investigates the tracking control problem of a single-joint robotic arm with direct-current (DC) motor system. Combining backstepping method, finite-time Lyapunov stability and fuzzy logic system (FLS), a finite-time fault-tolerant controller is designed. Simultaneously, to simply controller design and save communication bandwidth, we employ command filtered and event triggered strategies. The former avoids the problem of ‘differential explosion’ and the latter achieves communication resource conservation by intermittently triggered control signals. In addition, a FLS is used to construct a state observer and approximate unknown functions. Theoretical analysis proves that the proposed scheme enables all the signal in the closed-loop system to reach stable within a finite-time. Finally, the effectiveness of the proposed approach is verified through a simulation examples.