“…In recent years, a great deal of attention has been paid to the robust attitude control of spacecraft and several nonlinear control methods have been proposed, such as adaptive control, sliding mode control and active disturbance rejection control (Chen and Huang, 2009, 2014; Hu et al, 2008; Lai et al, 2012; Lee and Singh, 2015; Li et al, 2014; Zhong et al, 2013). Although these nonlinear control laws have shown adequate effectiveness and robustness in spacecraft attitude control systems, they can only guarantee asymptotic convergence, i.e.…”