HubRobo: A Lightweight Multi-Limbed Climbing Robot for Exploration in Challenging Terrain

This study presents the design and sequential control strategies of a novel lightweight climbing robot. The quadruped robot with a left–right and front–hind symmetric insect-type configuration has three degrees of freedom (3-DOF) actuated joints in each limb, a 3-DOF passive compliant spine gripper at each foot, and an actuator to open/close the gripper. First, we present the mechanical design and minimal hardware integration of the robot, which have helped successfully reduce the entire mass of the robot to 3 kg with a base height of 0.16 m. Next, a sequential strategy to process stable climbing locomotion is introduced. The implemented software architecture that realizes climbing motion is described. With the successful result of a teleoperation experiment on an indoor test field simulating the Martian uneven slalom (local max. inclination: 45°), we proved that the proposed sequential control strategy enables the robot to stably climb challenging terrain.