基于工具坐标标定改进的工业机器人零点位置自整定方法  

Improved Home Position Self-tuning Method of Industrial Robot Based on Tool Coordinate Calibration

作　　者：何英武 梅江平[1] 黄玄庆 陈绵鹏 郑东海 HE Yingwu;MEI Jiangping;HUANG Xuanqing;CHEN Mianpeng;ZHENG Donghai(School of Mechanical Engineering,Tianjin University,Tianjin 300354,China;Guangzhou CNC Equipment Co.,Ltd.,Guangzhou Guangdong 510535,China)

机构地区：[1]天津大学机械工程学院,天津300354 [2]广州数控设备有限公司,广东广州510535

出　　处：《机床与液压》2021年第5期14-19,共6页Machine Tool & Hydraulics

基　　金：国家重点研发计划(2017YFB1301802)。

摘　　要：在工业机器人应用过程中更换工具时需要重新标定工具坐标,一般情况下工具坐标通过固定点约束的3点法进行标定,此方式在机器人本身零点位置不准确的情况下往往会得到一个较差的结果。基于3点法中定点约束的原理,提出一种改进的工业机器人零点位置自整定方法,对出厂标定过的六自由度串联机器人,修改其零点位置与工具坐标的标准值产生给定误差,基于空间内一个固定点的约束关系,在已知机器人连杆参数的情况下建立机器人坐标变换模型,取21组机器人关节角与笛卡尔坐标数据作为辨识条件参数,机器人工具坐标与零点位置的偏差作为未知数据,通过最小二乘迭代算法计算出工具坐标与零点位置的偏差数据。将实验对象的整定结果和给定的误差参数进行对比,整定结果基本与给定误差一致,并通过比较自整定前后示教器上的位置显示值之间的误差值,证明了校准算法的可行性。It is necessary to recalibrate the tool coordinates when replacing tools in the application of industrial robots. Generally, constrained by a fixed point, the tool coordinates are calibrated by the three-point method. This method will get a bad result when the home position of the robot is not accurate. Based on the principle of fixed-point constraint in the three-point method, an improved home position self-tuning method for industrial robots was proposed. The calibrated 6-DOF serial robot was used as the experimental object, and the given error was generated by modifying the standard value of its home position and tool coordinate. Based on the constraint relationship of a fixed point in the space, the coordinate transformation model of the robot was established under the condition that the parameters of the robot link were known, and 21 groups of robot joint angles and Cartesian coordinate data were taken as the identification condition parameters.The deviation between the tool coordinate and the home position was regarded as unknown data, and the deviation between the tool coordinate and the home position was calculated by least-square iteration algorithm. Compared the experimental result with the given error parameter, the result is basically consistent. The feasibility of the calibration algorithm is proved by comparing the error of the position display value on the teaching device before and after self-tuning state.

关 键 词：工业机器人 坐标变换 工具坐标系 零点位置 自整定 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]