Research on high-smooth walking and adaptive obstacle-crossing of closed-chain multi-legged robot

The single-degree-of-freedom closed-chain leg mechanism has a limited foot-point trajectory, which leads to insufficient ground adaptability of the robot. This paper proposes a novel adaptive closed-chain leg mechanism that combines single-power swing-driven actuation, high-rigidity stable load-bearing, and adaptive reconfigurable obstacle-crossing characteristics. By establishing a single-power seven-bar nine-joint mechanism configuration and performing dimensional optimization, the lateral stride distance and vertical leg-lifting height are increased, enhancing obstacle-crossing performance. During the walking supporting phase, the non-circular gear profile is designed through dynamic coupling and phase matching to compensate for vertical center-of-mass fluctuation and longitudinal speed fluctuation, effectively reducing energy consumption while improving walking smoothness. An adaptive reconfiguration module is designed and analyzed to enable passive reconfiguration during the swing phase, allowing the robot to adaptively overcome obstacles across varying terrains. A multi-legged robot prototype was constructed, and typical obstacle adaptability experiments were conducted to verify the feasibility of the design.