压电驱动系统迟滞非线性-机械振动复合控制方法

A compound control method of hysteresis nonlinearity and dynamic behavior in piezo-based scanning systems

针对压电驱动系统中普遍存在的非线性及振动问题,提出了一种基于力反馈和输入信号轨迹优化方法的复合控制方法。首先,构建了压电驱动系统的动力学模型,推导了压电驱动器输入电压与力传感器输出电压之间的传递函数。在此基础上,引入积分环节,通过零极点的配置实现了系统阻尼比的主动控制,搭建了力反馈闭环控制系统。对输入信号激振机理进行了溯源分析,提出了基于最小加速度准则的输入信号轨迹优化方法。在此基础上,搭建了压电驱动系统复合控制平台,对控制效果进行了试验验证。试验结果表明,通过复合控制方法50 Hz时的压电驱动系统跟踪误差由9.33%下降为1.87%。与开环位移响应相比,系统跟踪精度提高了约4倍。与仅采用力反馈的闭环控制方法相比,系统跟踪精度提高了约1.6倍。

A compound control method was developed by integrating the closed-loop force feedback and the input shaping method to overcome the problem of the hysteresis and dynamic behavior in piezo-based scanning systems(PSS).The flexible mechanism and PEA were analyzed,and the dynamic model of the scanning systems was established.A force sensor and an integral controller were utilized in force feedback to directly augment the damping of the PSS.For the further control of mechanical resonance,based on the theory of minimum-acceleration trajectory planning,a time-domain input shaping method was developed.The turning sections of a scanning trajectory were replaced by smooth curves,while the linear sections were retained.The force feedback method was combined with the input shaping method to control the nonlinearity and mechanical resonance in high-speed PSS.The experimental results show that the tracking error at 50 Hz is reduced from 9.33% to 1.87% by the compound control method.Compared with the open-loop displacement response,the tracking accuracy of the system was improved by about 4 times.Compared with the closed-loop control method using only force feedback,the tracking accuracy of the system was improved by about 1.6 times.