Abstract: Using the parallel leg mechanisms, the life assistive walking robot can improve the payload-weight ratio, save the battery energy and prolong the walking time. Therefore, a quadruped walking robot with parallel leg mechanisms is presented. The robot features good stability and high safety, but the seat has a steep slope when the robot goes up and down stairs/steps. In order to cope with this problem, a walking robot with quadruped/biped reconfigurable parallel leg mechanisms is proposed. In general road, the robot walks on four legs, so that the afeared feeling of disabled people riding the biped walking robot can be eliminated; when going up and down stairs/steps, the robot walks on two legs, so that the body slope caused by the quadruped walking robot can be remedied. The implementation of mechanisms for the reconfigurable quadruped/biped walking robot is described. The 3-UPU parallel mechanism with three degrees of freedom and the 6-SPU parallel mechanism consisting of two 3-SPU are analyzed, and the application of parallel mechanisms in the reconfigurable quadruped/biped walking robot is discussed. The mobility of the reconfigurable quadruped/biped walking robot is analyzed through the calculation of degree of freedom. This research provides a theoretical basis for further investigation on the walking robot with quadruped/biped reconfigurable parallel leg mechanisms.

Key words: Degree of freedom, Parallel leg mechanism, Reconfigurable robot, Walking robot