“…There are many nonlinear systems in the real world. For example, chaotic systems (Li et al, 2017; Liu et al, 2019; Shen and Li, 2017; Zhao et al, 2019), bearing systems (Cao et al, 2019; Jin et al, 2019; Saket et al, 2019), and so on (Liu and Tong, 2016). Therefore, the controller design for the nonlinear systems is an important topic.…”