面向工业机器人的数字孪生建模精度补偿方法

A Digital Twin Modelling Accuracy Compensation Method for Industrial Robots

针对现有工业机器人智能装备建模感知监测精度缺失,依靠理论参数建模精度低等问题,本文以工业机器人铣削系统为研究对象,构建了高精度光栅尺实时测量机器人关节转角的数字孪生监测系统,避免了齿轮间隙、编码器丢码等关节转角误差对数字孪生建模准确度的影响;根据MD–H运动学建模方法建立了数字孪生驱动模型,采用L–M算法对工业机器人建模参数进行辨识修正,减少了机器人数字孪生模型中几何误差的影响;开发了数字孪生交互系统平台,用以监测、控制物理空间的工业机器人铣削系统的作业运动。利用辨识后的机器人关节参数构建的数字孪生模型,使得工业机器人铣削系统运动点位的建模精度从±1.6905 mm提高到了±0.3304 mm,提高了4.12倍,表明本文针对工业机器人数字孪生建模方法的正确性和建模参数辨识方法对建模精度补偿的可行性。

Aiming at the problems of the lack of perceptual monitoring accuracy of the existing industrial robot intelligent equipment modeling and the low accuracy of modelling based on theoretical parameters, this paper takes the industrial robot milling system as the research object and constructs a digital twin measurement system that measures the robot joint turning angle data in real time with a high-precision scale to avoid the influence of joint turning angle errors such as gear gap and encoder code loss on the accuracy of digital twin modelling. The digital twin drive model was developed based on the MD–H kinematic modelling method, and the L–M algorithm was used to identify and correct the industrial robot modelling parameters to reduce the influence of geometric errors in the digital twin modelling of the robot. The use of the identified robot joint parameters for modelling has improved the accuracy of the twin model for modelling the motion points of the industrial robot from ±1.6905 mm to ±0.3304 mm, increased by 4.12 times, which demonstrates the correctness of the digital twin modelling method and the feasibility of the identification of the modelling parameters.