基于滑模变结构控制理论的光存储伺服控制器设计

Design of Optical Storage Servo Controller Based on Sliding-Mode Variable Structure Control Theory

伺服控制器是光存储控制系统的基础,通过比较光学读取头下一时刻的位置指令和光电探测器探测的当前位置信号,经伺服控制器处理后输出电压信号,可以驱动电机带动光学读取头运动。为规避传统的经典控制方法,基于滑模变结构控制理论,设计出一种新型的光存储伺服控制器。该控制器对受控对象进行物理建模,建立受控对象的状态空间方程,设计相应的滑模切换面函数、滑模趋近律,从而得到内外环滑模变结构控制律。仿真结果显示,对比基于传统相位校正理论的伺服控制方法,其控制器阶跃响应的超调量和调节时间均较小,在增加有限的资源开销情况下,该伺服控制器具有更好的响应速度和稳定性能。

Servo controller is a fundamental component of the optical storage system. Processing the signal error between optical pick-up head （OPU） present position observed by the photo detector and the next position instruction, the controller generates a control signal which drives the motors in OPU. A new servo controller based on the sliding-mode variable structure control theory is researched. By means of building a physical model of the objective, the servo controller develops the state-space functions. A corresponding sliding-mode switching surface and the reaching law are also designed, and the inner-loop controller and outer-loop controller are finally designed. Compared with the classic controller based on phase correction theory, the simulation results show smaller overshoot and set time of the step response, which proves better response and robustness of the controller by increasing limited resource consumption.