Performance analysis and scale parameter optimization of a shipborne parallel stabilized platform

Abstract The shipborne 3UPS-3SS parallel mechanism is widely used in ship barge operation, but it has problems such as large volume and poor force transmission and acceleration performance. In order to solve the above problems, the kinematic/dynamic performance analysis and multi-objective optimization of scale parameters were carried out on the mechanism. The vector method is used to construct the position inverse solution model and constraint equations, and the kinematic inverse solution and velocity expression are derived, and the velocity Jacobian matrix is obtained. The fast polar coordinate search method was used to plot the reachable workspace by MATLAB software, and the volume expression of the workspace of the mechanism was obtained. The analytical equation of velocity and acceleration of each moving part was established by the differential method; the mechanism dynamics model was established by combining the virtual work principle, and the condition number was calculated and visualized based on the average mass matrix. Based on the distribution of the condition number of the velocity Jacobian matrix and average mass matrix, the force transferability and dynamic dexterity of the mechanism are evaluated. In the end, the workspace volume of the mechanism increased by 7.14%, the average minimum singular value increased by 196.43%, and the dynamic dexterity decreased by 55.69%, which provided a theoretical basis for the control and practical application of the mechanism.