Direct Force Sliding Mode Attitude Control based on Fully Actuated System Theory

The switching direct force device, which is a typical nonlinear control system, controls the attitude of projectile body. Therefore, a new design of direct force attitude control based on the theory of all-wheel drive system, which is more convenient than traditional methods in control parameters configuration, is carried out in this paper. In order to design the control parameters, the missile body model is transformed into a high-order fully actuated system based on fully actuated system theory. An improved pulse modulator is designed by differential tracker to obtain the angular acceleration information required by the fully actuated system. Sliding mode control is used to further improve the system performance in order to adapt to the uncertainties of the control system. Stability of this control system is proved by constructing the Lyapunov function. According to the result of simulation, it showed that steady-state error is reduced from 1° to 0.2° in comparison to PSR modulator when the thrust was deflected by 30% under the premise of ensuring the dynamic performance of the control system, which significantly improve the control accuracy.