Observer-based adaptive sliding-mode control under dynamic event-triggered scheme with actuator and communication faults

The adaptive technique and sliding-mode algorithm (SMA) for observer-based fault tolerant control is discussed with dynamic event-triggered scheme (DETS) in this article. Both the actuator and communication faults are considered, which implies that the inputs of system and controller are unreliable. Moreover, the switched DETS for controller-actuator channel is proposed to reduce bandwidth usage and actuator action frequency, which is different from the traditional event-triggered strategies. To deal with communication faults, which can be described as packet losses, the closed-loop system is modeled as a stochastic system. The SMA-based observer is designed to estimate system states, which lays the foundation for the design of control algorithm to mitigate the effects of faults and DETS. Then, a novel observer-based adaptive sliding-mode control (SMC) law based on hyperbolic tangent function is proposed to guarantee the stochastic globally uniformly ultimately boundedness and reduce chattering. At last, the proposed DETS and observer-based adaptive SMC law are applied into a robotic arm to illustrate the validity.