交流伺服系统改进型二自由度控制

Improved Two Degree of Freedom Control for AC Servo System

为提高交流伺服系统性能,设计了一种二自由度控制(two degree of freedom control,2DOFC)结构,在简单反馈控制结构的基础上,增加设定值微分跟踪器,保证系统能够更快更好地跟踪输入,反馈控制器的设计将滑模控制(sliding mode control,SMC)与内模控制(internal model control,IMC)相结合,其形式为内模PI控制器与切换鲁棒滑模控制器的线性组合,可使系统具有良好的扰动抑制能力。考虑到纯微分跟踪器的实现困难和对高频噪声的放大作用,采用不完全微分进行近似,同时反馈控制器可根据系统期望性能指标进行解析整定。仿真结果表明,所提方法不仅使得交流伺服系统具有较好的设定值跟踪和扰动抑制特性,而且对于系统参数摄动具有更好的鲁棒性。

To improve the performance of AC servo system,a two degree of freedom control(2DOFC)structure is designed.On the basis of simple feedback control structure,the seting value differential tracker is added to ensure that the system can track the input faster and better.Then,the design of feedback controller combines sliding mode control(SMC)with internal model control(IMC),its form is a linear combination of internal model PI controller and switching robust sliding mode controller,which can make the system have good disturbance rejection ability.Considering the realization difficulty of pure differential tracker and the amplification function of high-frequency noise,incomplete differential is used to make approximation,and the feedback controller can be adjusted analytically according to the expected performance index of the system.The simulation results show that the proposed method can not only make the AC servo system have super setting value tracking disturbance rejection characteristics,but also have better robustness to system parameter perturbation.