Kinematic Parameter Calibration of Redundant Robots Based on Improved LM Algorithm
As robots are widely used in industrial production and human-robot collaboration,the positioning accuracy of robots has become an important indicator of robot performance. Compared with the repeatable positioning accuracy which can be improved geometrically from the geometric parameters,the absolute po-sitioning accuracy also requires calibration of the non-geometric parameters. For redundant degree of free-dom robots,the non-geometric parameter solution is more complicated. Based on the analysis of the LM al-gorithm,a redundant robot calibration algorithm based on the improved LM algorithm is proposed. Firstly,the robot positive kinematic model is established by the hybrid five-parameter MD-H method,and the ve-locity-level Jacobi matrix is used to solve the robot kinematic parameters. During the experiment,a depth camera is used to measure the robot end position. The kinematic parameters are calibrated according to the measurement results using the improved LM algorithm. In the improved LM algorithm,the adaptability of the algorithm is improved by varying the initial step size,and the convergence speed is improved by dynam-ically updating the damping factor. The improved Quick-LM algorithm increases the convergence speed by 46.7％ compared with the traditional LM algorithm and reduces the maximum error of the robot by 9.18 mm,which proves the effectiveness and practicality of the improved algorithm.
robotskinematic parameter calibrationimproved LM algorithmkinematic model
万方数据
维普
