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针对小卫星3轴反作用轮姿态控制系统的非线性特性,应用误差四元数来描述姿态运动,将星体大角度姿态机动问题转化为误差四元数的调节问题。利用误差四元数和误差角速度建立滑动模态,并基于Lyapunov定理推导出一种姿态机动的引入角加速度负反馈的变结构控制律。仿真结果表明,该控制律能够提高收敛速度,降低机动过程中角速度的超调量和对起始力矩的要求。同时,在模型参数不确定和有外干扰的情况下该控制律也具有全局稳定性和鲁棒性。
According to the nonlinear characteristic of the small satellite 3-axis reaction wheel attitude control system, the quaternion of error is used to describe the attitude motion and the large-angle attitude maneuver problem is transformed into the adjustment of error quaternion. The slip modal was established by using the error quaternion and the error angular velocity. Based on the Lyapunov theorem, a variable structure control law of attitude maneuvering angular acceleration negative feedback was derived. Simulation results show that the proposed control law can improve the convergence rate, reduce the overshoot of angular velocity and the initial torque in the maneuvering process. At the same time, the control law has global stability and robustness under the uncertainties of model parameters and external disturbances.