Design, analysis and optimization of a novel redundant (6+1)-degree-of-freedom parallel mechanism with configurable platform

In this paper, a concept of adaptive capture for Autonomous Underwater Vehicles(AUVs) using parallel mechanism with configurable platform is proposed. By leveraging the deformation ca-pabilities of the configurable platform, the mechanism can capture AUVs of various sizes and orientations while also expanding its workspace, thereby increasing the success rate of grasping. Firstly, the mechanism design is conducted, a novel parallel mechanism consisting of three identical chains with a three-fold symmetrical Bricard platform is proposed. Secondly, the ki-nematics are obtained, based on which the workspace analysis is performed, and numerical verification is conducted. Thirdly, the Jacobian matrix is derived and verified, and the singularity analysis is carried out. Finally, the concept of a high-quality workspace tailored for the AUVs recovery scenarios is proposed. To achieve a maximum high-quality workspace while maintaining a compact mechanism structure, two indicators are proposed to evaluate the volume and shape of the workspace, and a multi-objective parameter optimization of the mechanism is conducted. The optimized mechanism can be effortlessly scaled to cover the target workspace while preserving minimal dimensions and compact structure.