Previous researchers optimized the robot kinematic parameters by measuring the position error of the robot end-effector, but lacked orientation information. The laser interferometer can simultaneously measure the position error and orientation error of the spatial straight line. Based on this, this paper aims to propose a robot kinematic calibration approach for measuring the pose errors of a robot end-effector using a laser interferometer to enhance the pose accuracy of the robot.
The approach specifically includes, based on the Modified Denavite–Hartenberg model, a kinematic pose error model is established using spatial line segments. The pose errors of the robot end-effector relative to the corner of the experimental test cube are measured using a laser interferometer. Subsequently, an improved model of the Sparrow Search Algorithm is developed, namely, the Chaotic Adaptive Sparrow Search Algorithm (CASSA). The kinematic error parameters are identified using the proposed CASSA, thereby completing the robot kinematic calibration.
The performance of the proposed approach is experienced on the TB6-R10 robot within the consideration of its workspace. The robot’s maximum positioning error is from 3.6804 to 0.6098 mm, and the average positioning error is from 1.0472 to 0.2856 mm, a reduction of 72.73%. In addition, the average orientation error is reduced from 478.8 to 219.4 arcsec, a reduction of 54.19%.
A new calibration approach is proposed and verified. The experimental results show that the pose accuracy is remarkably enhanced, providing a new measurement and identification method for robot kinematic calibration technology.
