含移动副及关节偏置的冗余机器人逆解方法  

Method for inverse solution of redundant robot with moving pair and joint offset

作　　者：车航 李露[2] 张磊[1] 杨旭 占文锋 CHE Hang;LI Lu;ZHANG Lei;YANG Xu;ZHAN Wenfeng(College of Mechanical and Electrical Engineering,Hohai University,Changzhou 213002;Hefei Institute of Physical Science,Chinese Academy of Sciences,Hefei 230031)

机构地区：[1]河海大学机电工程学院,江苏常州213002 [2]中国科学院合肥物质科学研究院,安徽合肥230031

出　　处：《机械设计》2024年第9期8-15,共8页Journal of Machine Design

基　　金：中国科学院合肥物质科学研究院院长基金项目(YZJJZX202013)。

摘　　要：对于智慧农业采摘机器人来说,具有腕部偏置的传统6自由度协作机器人难以处理藤蔓类植物大高度的操作空间。针对这一问题,文中在其基座底部增加一个移动关节构成一个冗余自由度机器人,采用改进的D-H法建立其正运动学模型,针对其逆运动学问题,提出了一种含移动副及关节偏置的冗余机器人逆解算法。基于蒙特卡洛法分析该机器人近似工作空间,并结合几何投影法求解出冗余参数的限位区间和初始值,采用代数法和优化冗余参数的方法,建立机器人末端位姿与其各关节变量之间的映射关系。为了验证该逆解算法的有效性,设计了离散点误差仿真试验和笛卡尔空间连续轨迹跟踪仿真试验,结果表明:采用该逆解算法的离散点绝对位置误差不超过7×10-13mm,轨迹跟踪中的运动参数光滑连续,满足实际需求,这对于需要额外增加移动轴的应用领域具有一定的参考价值。For the smart agricultural picking robot,the conventional six-degree-of-freedom collaborative robot with wrist offset has difficulty in handling the operating space of vine plants with large height.In this article,in response to this problem,a mobile joint is added at the bottom of the robot’s base,so as to constitute a redundant degree-of-freedom robot,and the positive kinemat-ic model is set up with the help of the improved Denavit-Hartenberg(D-H)method.In terms of inverse kinematics,an inverse-solution algorithm is proposed for the redundant robot with mobile pair and joint offset.The Monte Carlo method is used to analyze the robot’s approximate workspace;in combination with the geometric projection method,the limit intervals and initial values of the redundant parameters are solved;the mapping relationship between the robot’s end position and its joint variables is identified by means of the algebraic method and the optimized redundant parameters.In order to verify whether this inverse-solution algo-rithm is effective,efforts are made to design the simulation experiments of discrete points’error and continuous trajectory tracking in the Cartesian space.The results show that thanks to this inverse-solution algorithm,the error in the discrete points’absolute position does not exceed 7×10-13 mm,and the motion parameters in trajectory tracking are smooth and continuous,thus meeting the practical requirements.This study provides reference for those situations where additional moving axes are applied.

关 键 词：移动副 关节偏置 冗余机器人 逆运动学 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]