Computationally inexpensive fault tolerant control of uncertain non‐linear systems with non‐smooth asymmetric input saturation and undetectable actuation failures

This study investigates the tracking control problem of strict‐feedback systems with parametric uncertainties and asymmetric non‐smooth saturation as well as actuation faults. By combining a well‐defined smooth function with a Nussbaum‐type function, robust adaptive and fault‐tolerant control scheme is developed, which, as compared with most existing methods, exhibits several attractive features such as, capable of dealing with strict feedback systems with time‐varying unknown control gain and parametric uncertainties; able to cope with asymmetric and non‐smooth input saturation without requiring the prior knowledge of bound of input saturation; able to accommodate unexpected actuation faults; and structurally simple and computationally inexpensive. The proposed control schemes can guarantee all of the signals in the closed‐loop system are semi‐globally uniformly ultimate bounded. Finally, a simulation experiment is utilised to demonstrate the feasibility of the proposed design approach.