Type Synthesis of Multi-mode Mobile Parallel Mechanism Based on Planar 4R Single-loop Kinematic Chains

In order to synthesize a series of reconfigurable multi-mode mobile parallel mechanisms with geometric deformation characteristics, firstly, the planar 4R single-loop kinematic chains are used as the minimum structural unit, and the spatial geometric position relations and constraint types of multiple planar 4R single-loop kinematics chains can be obtained by utilizing the spatial geometric relations and the equivalence of the constraint force and the constraint couple. Secondly, the planar 4R single-loop kinematic chains are used as the kinematic limbs of the multi-mode mobile parallel mechanisms, and the multi-mode mobile parallel mechanisms can be synthesized by utilizing the spatial geometric relations of multiple planar 4R single-loop kinematic chains. Finally, the degrees of freedom of a series of multi-mode mobile parallel mechanisms are analyzed by using the screw theory, and the feasibility of the multiple modes can be verified.