Reconfigurable Design and Optimization‐Based Control of an Integrated Leg‐Arm Robot for Space Applications With an Underactuated Body

Integrated leg‐arm robots combining manipulation with locomotion show great potential for on‐orbit servicing. However, existing designs typically rely on additional actuators for mode switching, increasing mass, energy consumption, and control complexity. To address this issue, this article develops a quadrupedal integrated leg‐arm robot with an underactuated reconfigurable body. By utilizing a Sarrus mechanism as the body, the robot enables reconfiguration through its supporting limbs, achieving mode switching without additional actuators. Complete underactuated kinematic and dynamic models are established, complemented by an internal wrench mapping that characterizes load transfer within the underactuated body. These formulations provide the foundation for an optimization‐based, multilayered dynamics coupling control framework. Through coordinated prediction of internal/external wrenches and optimized distribution of contact wrenches, stable robot control is achieved. Experiments on a suspended gravity‐offloading testbed demonstrate that the prototype maintains system stability during locomotion, manipulation, and mode‐switching tasks. Energy comparisons show that the proposed method reduces total electrical energy consumption by 10.3% in locomotion and 21.8% in manipulation over kinematic control, validating the prototype and its control method under ground‐based gravity‐offloading conditions.