Motion Planning for Legged Robots via the Feasible Force Set

In order to make the quadruped robot better adapt to the complex environment and maintain stability during the movement, the movement of the robot should be planned. In the currently existing research, the gaits and footholds of the quadruped robot are pre-defined, and it is based on the accurate prior knowledge of the terrain. In this paper, the concept of the feasible force set is introduced, and the ability of the foot end during the supporting period is quantified , considering the different configurations at different joint angles and physical constraints of the legs. Secondly, the momentum theorem is used to determine the required foot forces during the robot movement, thereby determining the leg configuration that satisfies the requirements, and realizing the online selection of the footholds when velocity changes. The simulation results verify the rationality of the method. The results show that in the trot gait, the quadruped robot can find the feasible forces to meet the acceleration motion so that the robot can choose the footholds online, improving the robot’s adaptability to the environment