Kinematic analysis and optimisation of a gantry spraying robot for ship blocks

Nowadays, using existing automated coating equipment to meet the coating requirements of complex ship blocks both domestically and internationally has become challenging. As a result, this paper aims to propose a nine-axis gantry spraying robot system specifically designed for ship blocks. However, the presence of multiple redundant axes in the nine-axis gantry robot adds complexity to the inverse kinematics solution, making coating path planning difficult. To address this issue, the paper presents an inverse kinematics solution method for the nineaxis robot. It suggests keeping the X-axis and Y-axis of the crown block unchanged, while allowing the Z-axis to remain unchanged after completing the up and down movement. This transformation effectively simplifies the inverse kinematics problem of the nine-axis gantry robot into that of a six-axis robotic arm. Through simulation experiments in MATLAB and specific experiments on the Staubli RX160L robotic arm, the accuracy of the inverse kinematics analysis of the robot was confirmed. The differential evolution algorithm and the adaptive differential evolution algorithm were both utilized to solve the optimal inverse solution. The results indicated that the former achieved the optimal inverse solution with greater accuracy, whereas the latter was able to reach a better inverse solution more quickly. Data Availability: The authors confirm that the data supporting the findings of this study are available within the article.