Whole-body stability control of foot walking for wheel-legged robot on unstructured terrain

Purpose: Determining how to enhance foot walking ability and maintain pose control in unstructured terrain is a significant technological challenge for multilegged robots. To address this problem, the authors have devised a stable walking control strategy for the whole body to improve the stable pose control of multilegged robots. This paper studies a whole-body stable walking control strategy to improve walking ability and maintain a stable posture in order to enhance the stable posture control of quadruped robots. Design/methodology/approach: In this work, a stable walking control strategy for the whole body is investigated to improve the stable pose control of multilegged robots. First, the perception system is used to obtain the terrain height in the environment and send it to the trajectory planner to generate the foot-end trajectory for different terrains. Next, a stability control strategy is developed to constrain the body posture and motion space, including the main support triangle-based posture controller, foot-end force distribution-based barycentric horizontal position controller and barycentric height controller. Finally, simulations and real-world demonstrations using the robot are conducted on unstructured terrain (bulge and concave terrain). Findings: Results indicate that the control method designed in this work can effectively maintain posture stability and maximum movement space of the legs when the robot walks on unstructured terrain. Originality/value: This research can provide technical guidance and reference for wheel-legged robot foot walking on unstructured terrain. In the future, it can be used in various fields such as industrial rescue, material transportation and earthquake relief, greatly improving transportation efficiency.