Dynamical sliding mode control of spacecraft attitude using SGCMG systems

To solve the chattering problem in the conventional sliding-mode control, the dynamical sliding-mode control is adopted. Sliding function contains not only the error and its differential term, but also the feedback of the control-output. The expression of the controller´s output is a dynamic differential equation about the errors and the controller´s output. By this way the control performance is also improved. This paper deals with the modeling and simulation of attitude maneuver control for spacecraft by Single Gimbal Control Moment Gyroscopes (SGCMG) systems. At first, the dynamical model of SGCMG and the attitude dynamic model of spacecraft were constructed. Based on the pseudo-inverse solution with least square norm, the steering law of SGCMGs was designed. A null motion was added into the control law so that any internal singularity of gimbal configurations was avoided. With virtual prototype technology, the conflict between the complex mathematical model and joint simulation is solves. Based on the ADAMS and MATLAB, The united simulation system of attitude control for spacecraft with SGCMG systems is established. The simulation results show the effectiveness of the dynamical sliding-mode controller, and validate the feasibility and advantages in improving the design efficiency of attitude control system with this method.