Design of Variable-Gain First Order Sliding Mode and its Application to Spacecraft Attitude Synchronization

In this paper, we design a variable-gain first order sliding mode, in which the adaptive gain is state-independent and designed by two types of smooth, monotonically increasing and bounded functions. We modify the structure of the sliding mode even further by using an amplifying overall scaling factor. Both of the variable gain and the scaling factor can improve the control accuracy. Then we apply the newly designed sliding mode to the attitude synchronization of spacecraft. Simulation results show that, compared with the constant gain sliding mode, the proposed design ensures much higher control precision evaluated by the attitude synchronization error without more fuel consumption.