Mechanical Design and Redundant Motion Planning of a Hydraulic Quadruped Mobile Manipulator for Enlarging Operational Workspace

Abstract

The quadruped mobile manipulator (QMM) combines the environmental adaptability of a quadruped robot and the operation capabilities of a robotic arm. The design of the hydraulic QMM with an emphasis on large operational workspace considerations is reported, covering both mechanical design and motion planning aspects. A joint optimization method for determining the structural parameters under two operating conditions is introduced to balance the motion range and force output efficiency, reducing the cylinder drive force by compared with before optimization. Furthermore, this paper proposes a redundant motion planning method for the QMM, based on null-space projection and task feasibility assessment to expand the operational workspace. Through coordinated leg–arm motion, the robot's reachable workspace increases by . Physical experiments are conducted to demonstrate the effectiveness of the proposed method and the field capabilities of the QMM.