Analysis on Advancement of Hybrid Fuzzy Sliding Mode Controllers for Nonlinear Systems

Chattering phenomena is the major problem affecting sliding mode control (SMC). Also, finding a suitable structure and appropriate parameters values of fuzzy logic system (FLS) is a complex and difficult task. In addition, the stability of a general FLS is difficult to guarantee. Many types of combinations between FLS and SMC have been used to form an intelligent and robust controller that deviates from the limitations of each constituent and benefit from the advantages of each constituent. In this study, a survey of recent developments on the Hybridization of FLS (type-1) and SMC is presented. In addition, the differences between using the SMC in FLC or using FLC in SMC as well as their limitation and advantages are highlighted. It is found that the majority of the combinations made are intended to approximate the nonlinear sliding surface within the boundary layer. Limitations of the previous approaches and future research directions are pointed out. For novice researchers, this survey can serve as a foundation for their work while for expert researchers this review can serve as a benchmark for further advancement and exploration of other hybridization methods.