未知时变环境下机器人自校正阻抗控制研究  

A Study of Robot Self-Tuning Impedance Control in Unknown and Time-Varying Environment

作　　者：曾献文 翟敬梅[1] ZENG Xian-wen;ZHAI Jing-mei(School of Mechanical and Automotive Engineering,South China University of Technology,Guangdong Guangzhou 510000,China)

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510000

出　　处：《机械设计与制造》2021年第6期291-295,共5页Machinery Design & Manufacture

基　　金：广东省科技重大专项(2014B090920001)。

摘　　要：针对未知、时变环境下机器人力位控制需求,基于非线性接触动力学模型进行了阻抗控制的位置自校正修正算法研究。通过建立基于Hunt-Crossley非线性接触动力学模型的阻抗控制系统,构建了在刚性或柔顺作业环境下机器人末端位置与接触力之间的动态关系;在自校正控制系统中引入自扰动递推最小二乘辨识算法,以接触力误差最小为设计指标,设计了阻抗控制的位置自校正修正算法,在预测控制同时进行接触动力学参数在线跟踪辨识,解决了在材料力学特性未知或存在时变的环境下,力跟踪的实时性和准确性问题;仿真实验模拟了环境力学特性参数事先未知且在不同作业区域间存在差异的应用场景,结果表明,该算法能够实时进行阻抗控制的自适应位置调整,保证了力位跟踪控制的快速响应性和收敛性,稳态力跟踪误差控制在2%以内,环境力学特性发生变化时的控制调整时间仅约7个采样周期,相较对比算法减少约70%。Aiming at the robot force and position control demand in unknown and time-varying environment,the position adaptive correction algorithm for impedance control is studied based on nonlinear contact dynamics model.By establishing an impedance control system based on the Hunt-Crossley nonlinear contact dynamics model,the dynamic relationship between the end position of the robot and the contact force in stiff or compliant working environment is constructed;Self perturbing recursive least squares identification algorithm is introduced into self-tuning control system,the self-tuning position correction algorithm for impedance control is designed with the minimum contact force error as the design index,which makes predictive control while identifying contact dynamics parameter online,this algorithm solves the problem of real-time and accuracy of force tracking in the environment where the mechanical properties of the material are unknown or variable.The simulation experiment simulates an application scenario where the environmental mechanical property parameters are unknown in advance and different between working areas,as the result shows,the algorithm can ensure fast response and convergence of force and position tracking control effect by adaptively adjusting reference position of the impedance controller.The steady-state force tracking error is controlled within 2%,and the control adjustment time when the environmental mechanical properties change is only about 7 sampling periods,which is about 70%less than the comparison algorithm.

关 键 词：未知时变环境 力位控制 非线性接触动力学模型 阻抗控制 参数辨识 自校正控制 

分 类 号：TH16[机械工程—机械制造及自动化] TP24[自动化与计算机技术—检测技术与自动化装置]