最优ZPETC在伺服跟踪控制中的应用

在高精度伺服跟踪控制系统中,为使输出响应能完整地跟踪输入指令,不仅要求输出与输入之间的相位差为零,而且要求幅值一致,通常采用零相位误差跟踪控制器(ZPETC)作为前馈控制器,补偿相位误差,但同时也产生一定的增益误差.为改善ZPETC的跟踪性能,提出一种基于L2-范数优化的前馈控制器设计方案,通过选取适当的目标函数,设计出最优的数字前置滤波器(DPF),将此滤波器与ZPETC串联构造成最优ZPETC.仿真结果表明,该优化设计方案,既补偿了相位误差,又改善了系统的增益性能,从而提高了系统的跟踪精度.

Application of Optimal ZPETC in Servo Tracking Control

In high precision servo tracking control system,in order to make the output response track perfectly the input command,the phase error between output and input is required to be zero,at the same time the magnitude is required to be uniform.Generally zero phase error tracking controller(ZPETC) is used as feedforward controller to compensate for the phase error,but this will also cause small gain error.To improve the tracking performance of the ZPETC,the optimal design scheme of feedforward controller based on L_(2)-norm is proposed in the paper.The optimal digital prefilter(DPF) is designed by selecting proper objective function.By cascading the developed DPF to ZPETC,an optimal ZPETC is obtained.The simulation results show the optimal design scheme proposed in the paper can not only compensate for the phase error,but also improve the gain performance of the system,thus the tracking accuracy of the system is greatly enhanced.