基于力/位混合算法的7自由度机械臂精细操控方法  

Accurate Operation Control Method Based on Hybrid Force/Position Algorithm for 7-DOF Manipulator

作　　者：常健[1] 王亚珍 李斌[1] 

机构地区：[1]中国科学院沈阳自动化研究所机器人学国家重点实验室,辽宁沈阳110016 [2]浙江省特种设备检测研究院,浙江杭州310003

出　　处：《机器人》2016年第5期531-539,共9页Robot

基　　金：国家科技支撑计划(2014BAK12B01)

摘　　要：为了使冗余机械臂在具有良好的自治性和灵活性的同时保证末端的执行精度,提出一种基于力/位混合控制的冗余机械臂精细控制方法.通过建立准确的运动学模型,分析机械臂系统的运动特性,利用固定角度与梯度下降相结合的方法求动力学逆解.在对机械臂的力/位混合控制律建模的基础上,利用位置控制和力控制对机械臂末端的运动轨迹进行规划.针对受环境约束的机械臂的控制问题,提出冗余自由度机械臂的适从坐标系建立方法,使得末端执行器能够在任意曲面完成作业任务.在仿真分析和实验中,令机械臂末端跟随任意设定的曲线轨迹到达给定点.通过多次测量得出,力精度误差小于2%,并且在保证作用力方向精确的条件下,机械臂末端轨迹的偏离值小于5%.结果表明,所设计的力/位混合控制方法对7自由度机械臂控制精度效果良好.To ensure the execution accuracy of the end-point as well as the autonomy and flexibility of redundant manipulators, a precise control method based on hybrid force/position algorithm is proposed. Firstly, motion characteristics of the manipulator system are analyzed by establishing precise kinematic model. Then, the inverse dynamic can be solved by the combination of gradient descent method and fixed angle method. And the path of the manipulator end-point can be planned according to the force and position control methods by establishing the model of hybrid force/position control law. For the restricted manipulator control in complex environments, an algorithm for establishing the slave coordinate system of the redundant DOF（degree of freedom） manipulator is proposed to enable the end-effector to operate on a random curved surface.Finally, the manipulator end-point is controlled to track an arbitrary preset curve to a given point in simulation analysis and experiments. As results of multiple measurements, the errors of force accuracy are less than 2%, and the deviation values of the end-point＇s trajectory are less than 5% while guaranteeing the precision of force direction. Results show that the proposed hybrid force/position control method performs well in precision on a 7-DOF manipulator.

关 键 词：力/位混合控制 冗余机械臂 动力学逆解 环境约束 力精度 

分 类 号：TP24[自动化与计算机技术—检测技术与自动化装置]