Kinematic Modelling Without Singularity and Nonlinear Control of Satellite Attitude Using Direct Adaptive and Fuzzy PD Control Methods

Adaptive control technique is taken into consideration because of overcoming the problem of existence of uncertainties in the space missions.In this paper, a novel optimal direct adaptive control technique which is based on Markov parameters is presented. In this technique, the system's performance is expressed based on rotation matrices, and this method doesn't have a singularity problem. The problem of satellite attitude control using this method and nonlinear thruster actuator in existence of uncertainty in moment of inertia is analyzed. The novel adaptive controller using on-off thrusters is robust to inertia changes. In this paper, a mamdani fuzzy logic is used to schedule the gains of PD control method, and the satellite attitude control problem using a fuzzy controller is simulated. With considering the settling and rise times, it's shown that the fuzzy controller is better than the presented adaptive controller. Also, the problem of satellite attitude control using the novel adaptive controller in presence of a constant disturbance is analyzed, and simulation results illustrate that the new adaptive control is robust to a constant disturbance.