基于改进型RLM算法的六轴机械臂运动学标定实验

六自由度机械臂为高维性、强耦合的非线性时变系统,其模型较复杂,参数辨识易受外界扰动影响,导致末端绝对定位精度低,精度一致性差等问题。以某型六轴机械臂为研究对象,根据微分运动学原理并忽略高阶项,获得末端线性误差模型,提出了收敛速度快且鲁棒性较强的改进型RLM算法进行几何参数的误差辨识,在此基础上搭建综合标定实验平台,利用静态测量精度较高的API T3三维激光跟踪仪采集工作空间中灵敏度较高的样本位姿点,根据国际标准ISO 9283中的位置精度评价标准,比较标定前后的位置误差分布区间,并对分析结果给出评价和总结,完成六自由度工业机械臂本体标定实验。

Kinematic Calibration Experiment of Six Axis Manipulator Based on Improved RLM Algorithm

The six degree of freedom manipulator is a high-dimensional and strongly coupled nonlinear time-varying system.Due to its complex model,parameter identification is susceptible to external disturbances,resulting in low absolute positioning accuracy and poor accuracy consistency.A type of six axis manipulator was taken as the research object,according to the principle of differential kinematics and ignoring higher-order terms,the end linear error model was obtained.An improved RLM algorithm with fast convergence and high robustness was proposed to identify the errors of geometrical parameters.On this basis,an integrated calibration experiment platform was built and the API T3 3D laser tracker with high static measurement accuracy was used to acquire the high sensitivity sample pose points in the workspace.According to the position accuracy evaluation standard in the international standard ISO 9283,the distribution range of position error before and after calibration was compared,and the analysis results were evaluated and summarized.The calibration experiment of industrial manipulator with six degrees of freedom was completed.