Integrated Control of D-SLIP and CPG for Spine-joint Robot under Lateral Impact

Aiming at the problem that quadruped robots are prone to instability and lateral deviation when subjected to lateral impact, a control strategy is proposed for anti-lateral impact of a spine-joint quadruped robot based on the fusion of a damped spring-loaded inverted pendulum (D-SLIP) and a central pattern generator (CPG). Lateral impacts are classified into unstable and non-unstable impacts based on the force balance conditions of the foot-end contact points. D-SLIP model is adopted for single-leg control. The influence of spine-joint motion control parameters is considered, and CPG model are utilized to achieve coupled control between the 4 legs and the spine-leg system. Disturbance rejection joint control is applied to resisting lateral impacts. Active side-swing initiation conditions are defined based on the hip joint lateral torque. The lateral displacement distance of the robot after a lateral impact is shortened through active side-sway displacement planning. Simulation and experimental validation using Webots and Simulink demonstrate that, compared to traditional inverted pendulum control strategies, the proposed control strategy reduces roll and pitch angle disturbances by 25% and 20% respectively, shortens lateral displacement by 35%, and improves the stability and robustness of the spine-joint robot in resisting lateral impacts.