面向机器人标定的单激光跟踪仪顺序多站式测量系统建模与分析

为实现大型串联工业机器人的高精度标定,搭建了一种单激光跟踪仪的顺序多站式测量系统。该系统仅需单台激光跟踪仪,先后在不同的基站位置对工业机器人的末端位置进行独立测量,并基于多边测量方法计算机器人的末端位置。计算过程中仅需激光跟踪仪的距离信息,有效地优化了末端位置的测量不确定度。首先,建立了该测量系统的仿真模型,深入地分析了测量点的数量与分布形状、测量距离以及工业机器人定位精度等因素对系统测量精度的影响;然后,依据分析结果确定单激光跟踪仪顺序多站式测量系统的搭建方案。实验结果表明:该系统在2.5m距离上的测量误差仅为0.023mm,优于激光跟踪仪的测量精度,满足大型串联工业机器人参数标定的测量精度要求。

Modeling and Analysis of Sequential Multi-lateration Measurement System Based on Single Laser Tracker for Robot Calibration

To implement the accurate calibration of large serial industrial robot, a sequential multi-lateration measurement system of single laser tracker is presented. The system only needs single laser tracker to measure the end position of industrial robots in different base stations. The end position of robots is calculated based on the multilateral measurement method. Due to the distance data needed in the calculation, the measurement uncertainty of position can be effectively reduced. Firstly, the simulation model of the measurement system is established. The influence of the number of the measuring points, the distribution shape, the measuring distance and the positioning accuracy of industrial robots on the measuring accuracy of the proposed system is intensively studied. Secondly, according to the analysis results, the construction scheme of the sequential multi-station measurement system based on single laser tracker is determined. The experimental results show that the measurement error of the system is only 0.023mm at 2.5m distance, which is better than the accuracy of laser tracker. It can satisfy the measurement accuracy requirement of parameters calibration of the large serial industrial robot.