永磁球形步进电动机变结构控制算法

摘要

In this paper,a switching control algorithm is presented in view of controlling the permanent magnet spherical stepper motor effectively.Programmable current sources are applied to control the magnitude of the currents in the stator coils instead of controlling the motor with relays.The dynamic model of the rotor expressed with Cardan angle rotation is set up in rotor-fixed coordinates frame.One control algorithm is designed based on input-output stability theory to drive the motor without the angular accelerations feedback in unloaded mode.Then the switching control algorithm applied in the situation that the load affected the rotation inertia of the axes is developed.Finally,a boundary layer is interpolated to eliminate control chattering.Simulation results show good performance of the new control laws.It has smaller tracking errors and the steady-state errors are reduced to less than 0.01 radians.%提出了永磁球形步进电动机的一种变结构控制算法.该算法用可控电流源控制定子电磁线圈通电电流的幅值替代继电器控制方式.首先在转子固连坐标系内基于卡尔丹角旋转建立了转子动力学模型.然后在电动机空载运行的模式下,设计了一种无需角加速度反馈信号的基于输入一输出稳定性理论的控制算法.接着针对电动机负载运行,各轴向转动惯量发生变化的情况设计了变结构控制算法.最后,在变结构控制算法中插入边界层以消除抖振现象.仿真结果表明,新的控制算法具有更小的跟踪误差,稳态误差小于0.01rad.