A Configuration Synthesis Method of Reconfigurable and Decoupled Wheel-legged Mechanical Leg

A set of fully-decoupled reconfigurable wheel-legged hybrid mechanical leg configurations are synthesized based on the screw theory and the motion bifurcation principle of reconfigurable mechanism. According to the degree of freedom requirements of wheel-leg mode, the wheel-leg transformation mechanism is analyzed, and then five kinds of main motion limbs are synthesized and selected. The principle and scheme of constraint limb arrangement are proposed based on the wheel-leg transformation mechanism, and the constraint limbs are obtained based on the screw theory. According to the geometric conditions of the main motion limbs and the constraint limbs, the axis transformation of the kinematic pair and the decomposition and combination of the kinematic pair are carried out, and 134 constraint limbs are finally obtained. Based on the concept of motion decoupling of parallel mechanism, the selection condition of driving pair is derived, and the position of driving pair in each constraint limb is determined. The correctness of the mechanism synthesis method is verified by an example. The synthesized mechanical leg realizes the wheel-leg mode switching based on constraint singularity, which reduces the time consumption required for configuration transformation and makes mode switching more efficient. In addition, there is no need to lock the joints related to leg mode motion during wheel motion due to the existence of structural constraints, which reduces energy consumption and driving control difficulty. © 2024 China Ordnance Industry Corporation. All rights reserved.