“…Because the first simple three-dimensional chaotic system has been proposed by Lorenz (1963), scientists have discovered the great application of the chaos systems in secure communication (Li et al , 2020; Wang et al , 2020; Yu et al , 2020a; Lin et al , 2021a), image encryption (Xu et al , 2020a; Cheng et al , 2020; Xu et al , 2020b; Zeng and Wang, 2021; Deng et al , 2021) and neural network (Lin et al , 2020a; Lin et al , 2020b; Lin et al , 2020c; Lin et al , 2020d; Yao et al , 2020). To meet the needs of engineering applications, researchers are committed to construct chaotic systems with more dynamic behaviors such as transient chaos (Xie et al , 2021), hyperchaos (Yu et al , 2021; Wu et al , 2018; Feng et al , 2017), coexisting attractors (Lai et al , 2019; Pham et al , 2017a; Lai and Chen, 2017) and bursting dynamics (Zhou et al , 2020; Wen et al , 2020; Wen et al , 2019; Lin et al , 2021b). It is widely recognized that equilibrium points of a chaotic system play important roles in chaos theory.…”