曲面轮廓恒力跟踪的非线性双闭环控制

针对机器人在跟踪未知曲面轮廓运动时,由于缺乏位置信息导致的接触力不恒定的问题,提出了非线性双闭环控制方法。该方法中的双闭环包括运动倾角的实时反馈校正器,以及基于非线性PID的法向接触力控制器。非线性PID控制器是由非线性跟踪微分器(TD)和状态误差反馈(SEF)构造的,基于线性PID框架的非线性控制器。首先,根据受力模型得到基于力反馈的运动倾角校正策略;另外,考虑到多维力传感器维间耦合的影响,对Maxwell三维力传感器的解耦矩阵进行了标定;同时,提出了力信号的自适应惯性滤波方法,改善了滤波器的灵敏度和稳定性,综合性能提高了34.42%;最后,实验验证了双闭环控制方法能有效提高力控制精度和稳定性,具有较强的可执行性和适应能力。

Nonlinear dual-loop force controller of contour following

Aiming at the problem that the contact force caused by the lack of position information is not constant,the nonlinear double closed-loop control method was proposed for the robot to track the unknown surface contour.Double-loop in this method includs movement angle adjuster based on real-time feedback,and the nonlinear PID normal contact force controller.This method is a nonlinear controller based on classical PID frame,composed of nonlinear tracking differentiator (TD) and state error feedbacks (SEF).First,according to the force model,the motion inclination correction strategy based on force feedback was proposed.In consideration of the cross axis coupling of multi-dimensional force sensor,the decoupling matrix of Maxwell force sensor was calibrated.Meanwhile,adaptive inertia filtering method was proposed to improve the sensitivity and stability of filter,and the comprehensive performance is improved by 34.42％.Finally,the dual-loop control method is verified by experiments.The proposed method can effectively improve the precision and stability,with a strong ability to adapt and enforceability.