基于6参数模型的6R串联机器人运动学参数辨识  

Kinematic Parameter Identification for 6R Serial Robots Based on a 6-Parameter Model

作　　者：白云飞[1] 丛明[1] 杨小磊[1] 刘冬[1] 

机构地区：[1]大连理工大学机械工程学院,辽宁大连116024

出　　处：《机器人》2015年第4期486-492,共7页Robot

基　　金：辽宁省科技创新重大专项项目--智能型搬运与加工机器人(201302001)

摘　　要：为了避免运动学参数误差辨识中存在参数不连续、计算收敛速度慢的现象,基于一种6参数模型,在DH(Denavit-Hartenberg)法建立的杆件坐标系上建立了6R串联机器人的误差模型,并给出了参数转化公式.设计了计算机仿真实验,在存在驱动器、测量仪器随机噪声误差的条件下对比了使用MDH(改进DH)参数误差模型和6参数模型的仿真辨识效果.6参数模型和MDH模型辨识后定位平均误差分别降低了96.1%和52.9%.结果显示6参数模型具有良好的完备性、连续性.6参数模型的误差参数范围可以从制造公差中得出,辨识速度高于MDH模型,通过公差控制参数范围,消除了没有达到极小性要求对误差辨识的影响.应用此方法对一台SR165型机器人进行参数辨识,定位平均误差由2.5 mm降低至0.35 mm.To avoid discontinuous parameters and low-speed convergence in kinematic parameter error identification, an error model for 6R serial robots based on a 6-parameter model is established in the link coordinate systems set up with DH （Denavit-Hartenberg） method. A formula for parameter conversion is derived. In order to compare the results produced by the MDH （modified DH） model and the 6-parameter model, a computer simulation experiment in presence of random noise errors in drives and measuring instruments is designed. The average absolute error is decreased by 96.1% and 52.9% respectively by using the 6-parameter model and the MDH model. The results show that the 6-parameter model has completeness and continuity. The range of model parameters can be derived from the manufacturing tolerances. The 6-parameter model is superior to the MDH model in terms of identification speed. By limiting the parameter range, the influence of lack-of- minimality on error identification is eliminated. The method is applied to parameter identification of an SR165 robot, and the average positioning error is reduced from 2.5 mm to 0.35 mm.

关 键 词：工业机器人 结构误差 参数辨识 

分 类 号：TP24[自动化与计算机技术—检测技术与自动化装置]