Purpose

The purpose of this paper is to improve the positioning accuracy of 6-Dof serial robot by the way of error compensation and sensitivity analysis.

Design/methodology/approach

In this paper, the Denavit–Hartenberg matrix is used to construct the kinematics models of the robot; the effects from individual joint and several joints on the end effector are estimated by simulation. Then, an error model based on joint clearance is proposed so that the positioning accuracy at any position of joints can be predicted for compensation. Through the simulation of the curve path, the validity of the error compensation model is verified. Finally, the experimental results show that the error compensation method can improve the positioning accuracy of a two joint exoskeleton robot by nearly 76.46%.

Findings

Through the analysis of joint error sensitivity, it is found that the first three joints, especially joint 2, contribute a lot to the positioning accuracy of the robot, which provides guidance for the accuracy allocation of the robot. In addition, this paper creatively puts forward the error model based on joint clearance, and the error compensation method which decouples the positioning accuracy into joint errors.

Originality/value

It provides a new idea for error modeling and error compensation of 6-Dof serial robot. Combining sensitivity analysis results with error compensation can effectively improve the positioning accuracy of the robot, and provide convenience for welding robot and other robots that need high positioning accuracy.

中文翻译：

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六自由度串联机器人误差补偿及灵敏度分析研究

目的

本文旨在通过误差补偿和灵敏度分析的方式提高六自由度串联机器人的定位精度。

设计/方法/方法

本文采用Denavit-Hartenberg矩阵构建机器人的运动学模型；通过模拟估计单个关节和多个关节对末端执行器的影响。然后，提出了基于关节间隙的误差模型，以便预测关节任意位置的定位精度以进行补偿。通过对曲线路径的仿真，验证了误差补偿模型的有效性。最后，实验结果表明，误差补偿方法可以将双关节外骨骼机器人的定位精度提高近76.46%。

发现

通过关节误差敏感性分析，发现前三个关节，尤其是关节2，对机器人的定位精度贡献很大，为机器人的精度分配提供了指导。此外，本文创造性地提出了基于关节间隙的误差模型，以及将定位精度解耦为关节误差的误差补偿方法。

原创性/价值

为六自由度串联机器人的误差建模和误差补偿提供了新思路。将灵敏度分析结果与误差补偿相结合，可以有效提高机器人的定位精度，为焊接机器人等需要高定位精度的机器人提供便利。