A study of the optimal poses based calibration method for kinematic parameters of Stewart robot

Due to the high stiffness and load capacity, the Stewart robot is widely used in the high-end manufacturing. However, the accuracy performance of Stewart robot is affected by various factors. This paper carries out a study on the accuracy improvement method of the Stewart robot. The proposed method is composed of the kinematic calibration and the tool transformation calibration methods. The optimal poses are selected by the IOOPS algorithm based on the observational index O
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. The optimal pose number is determined as 75. Several experiments have been done to evaluate the performance of the proposed method. The experimental results show that the average position error and average attitude error of the Stewart robot is reduced from (0.4937mm, 0.0346°) to (0.0067mm, 0.003°). The position and attitude accuracy performance is improved by 98.6% and 91.3% respectively. It can be seen that the proposed calibration method can efficiently improve the robot accuracy performance.