柔性机械臂的变结构振动控制研究

STUDY ON VARIABLE STRUCTURE VIBRATION CONTROL FOR FLEXIBLE MANIPULATOR

当机械臂的质量很轻,尤其是空间应用场合,机器人系统将受到高度柔性限制并且不可避免地产生机械振动.本文为了证实提出的控制不期望残余振动的方法,设计并建立了柔性机器人实验平台.控制方案采用交流伺服电机通过谐波齿轮减速器驱动柔性机械臂,利用粘贴在柔性臂上的压电陶瓷片(PZT)作为传感器来检测柔性臂的振动.对由于环境激励,尤其是在电机转动(机动)时由于电机力矩产生的振动,采用了几种主动振动控制器包括模态PD控制,软变结构控制(VSC)和增益选择变结构方法,进行柔性臂的振动主动控制实验研究.通过实验比较研究,结果表明采用的控制方法可以快速抑制柔性结构的振动,采用的控制方法是有效的.

When the manipulator is lightweight, especially for space application, the robotic systems are subject to high degree of flexibility and encounter unavoidable mechanical vibration. In this paper, the experimental setup of flexible manipulator was designed and built to verify the approach proposed for actively controlling the unwanted residual vibration. The control scheme consists of one AC servomotor actuator to drive the flexible link through harmonic gear speed reduction, and piezoelectric ceramics （PZT） patch attached to the surfaces of the flexible link used as sensors. Several active vibration controllers including the modal PD, soft variable structure control （VSC） and gain select VSC method were investigated to suppress the unwanted vibration due to environmental stimulation, especially the undesirable oscillations caused by the motor torque during the hub slewing motion. The comparative experimental results showed that the vibration of the system was significantly suppressed, and the adopted control methods were effective.