Actuator Failure Compensation For Attitude Control Of Rigid Body

With the development of science, the research on attitude of rigid body can be divided into research on modeling and control methods. At present, study on the attitude of rigid body is mainly on three-axis drive. The actuators are made up of jet thrusters or momentum fly wheel devices. When spacecraft flying, its devices maybe braking- stuck, even failure completely due to fuel consumption or lubrication, thus make its dynamic performance change. The actuator failure has uncertainties, failure mode and which actuators are unknown. If the disabled actuator can not be compensated, the spacecraft maybe end, and case great loss.Actuator failure compensation usually has two compensation methods. One method is hardware design, each axis is equipped with redundant backup device drivers, once a driver cannot work effectively, and the back-up immediately to work, but this method can increase the weight of the spacecraft and cost. Another method is adopted to control theory, when design controllers considering the possible actuator failure, using three axis dynamic coupling characteristics to achieve attitude control. The last method does not need additional investment. Therefore, research the actuator failure compensation algorithm has the significance on theory and engineering.This paper uses the example of spacecraft systems to illustrate the control schemes of actuator failure systems. The content of the research includes the following:Firstly, the main results on the kinematics, dynamic and control methods of the attitude systems were discussed on the basis of many references. Some development tendencies of control schemes were introduced. A detailed comment on the present development of the control systems is given, and the problems of the attitude control on a rigid body are analyzed.Secondly, based on the Newton-Euler theorem, the mathematical model of rigid body is established. Four kinds of parameters for representing the attitude of a rigid body are studied. Formulas are given for changing for many kinds of parameters to the other three kinds of Parameters. The model for attitude stabilization is established.Thirdly, in this section, we discuss an sliding control method for the attitude control of a rigid body. The control law is proposed and the convergence analysis is carried out based on Lyapunov stability theory. Simulation results are presented showing the performance of the systems.Fourthly, when one actuator failure, designed the piecewise continuous variables and a continuous feedback control law with a periodic time-varying to achieve the attitude and angular velocity stabilization when the actuator failure. Finally, the numerical simulation results show that the method is effective.Fifthly, with adaptive and sliding control designed the system control law, when the actuator failure. Simulation results demonstrate the practical applicability of the proposed approach.Finally, the comparisons of several control methods are introduced which describes the advantages and deficiencies. In this paper, each control method is given stability provability and simulation example as well results respectively, the results illustrate the effectiveness of the control methods. At last, presents the main conclusions and possible avenues of further research. The advent of this paper is instrumentally and referentially significant for the attitude controller design of a rigid body.