考虑关节柔性误差的机器人参数辨识方法研究

摘要

考虑到工业机器人绝对定位精度较低,无法满足高精度加工的需要,故提出了一种综合型误差补偿方法.以改进的D-H模型为基础,建立机器人末端工具中心点的距离误差模型,同时对主要受力关节2和3由于自重或者外加负载产生的柔性变形误差进行了研究,建立了柔性误差模型,最后以激光跟踪仪作为测量设备,利用最小二乘法对模型进行求解,通过修正控制器参数补偿误差提高机器人定位精度.经过补偿,自主研发的机器人定位精度有明显的提高,从之前的3.548 mm降至0.939 mm.%Because of its lower absolute positioning,an industrial robot is unable to meet the needs of high-precision processing,so this paper puts forward an integrated error compensation method.The error model of a tool's central points based on distance accuracy is developed by the modified Denavit-Hartenberg model.Meanwhile,this paper studies the positioning error of the stressful joints 2 and 3,which is caused by the robot's gravity and external load;then it establishes the flexible error model.Finally,a laser tracker is used as the measurement equipment,and the error model is solved by the least squares method.The positioning error of the robot is compensated for by updating the parameters of its controller to improve the positioning accuracy.After the compensation,the mean positioning accuracy of the robot is significantly improved,which previously is 3.548 mm to 0.939 mm.