设计了自适应逆控制的永磁同步电机(PMSM)控制系统,控制系统采用双闭环结构的矢量控制,将自适应逆控制方法引入速度控制。运用非线性自适应滤波器,实现系统的建模与逆建模,并引入滤波器构成了速度控制器,采用最小均方差(Least Mean Square,LMS)自适应滤波算法在线调整其权函数,实现速度的精确控制。在基于DSP的永磁同步电机速度控制系统平台上的实验结果表明,非线性滤波器能够建立电流环模型,提出的非线性自适应逆控制方法能够实现精确的速度控制。与PID控制方法相比,具有更精确的速度跟踪性及更快的响应速度。
An eigenaxis maneuver strategy with global robustness is studied for large angle attitude maneuver of rigid spacecraft. A sliding mode attitude control algorithm with an exponential time-varying sliding surface is designed, which guarantees the sliding mode occurrence at the beginning and eliminates the reaching phase of time-invariant sliding mode control. The proposed control law is global robust against matched external disturbances and system uncertainties, and ensures the eigenaxis rotation in the presence of disturbances and parametric uncertainties. The stability of the control law and the existence of global siding mode are proved by Lyapunov method. Furthermore, the system states can be fully predicted by the analytical solution of state equations, which indicates that the attitude error does not exhibit any overshoots and the system has a good dynamic response. A control torque command regulator is introduced to ensure the eigenaxis rotation under the actuator saturation. Finally, a numerical simulation is employed to illustrate the advantages of the proposed control law.
It is now well known that the time-varying sliding mode control （TVSMC） is characterized by its global robustness against matched model uncertainties and disturbances. The accurate tracking problem of the mechanical system in the presence of the parametric uncertainty and external disturbance is addressed in the TVSMC framework. Firstly, an exponential TVSMC algorithm is designed and the main features are analyzed. Especially, the control parameter is obtained by solving an optimal problem. Subsequently, the global chattering problem in TVSMC is considered. To reduce the static error resulting from the continuous TVSMC algorithm, a disturbance observer based time-varying sliding mode control （DOTVSMC） algorithm is presented. The detailed design principle and the stability of the closed-loop system under the composite controller are provided. Simulation results verify the effectiveness of the proposed algorithm.
