Center of mass and its domain for heavy hexapod robots

Center of mass domain of a hexapod robot must be determined in order to analyze the mobility performance and accomplish the high-fidelity simulation. Hexapod robot is simplified as a system of particles based on the structure characteristics of the developed hydraulically actuated hexapod robot. Position vectors of all mass points are established by coordinate transformation. Center of mass position in any gesture and its domain of a hexapod robot are derived. Simulation platform is established based on Vortex. Position control functions of hydraulic cylinders are solved according to the motion planning and the geometric relationship of robot. Simulation of walking process by using the proposed mass center position is completed. Hexapod robot prototype is developed, and centroid position of the body is measured according to the force sensors installed on the foot of the robot. Correctness of theoretical analysis results is proved. Walking tests of the robot prototype are accomplished, and the results show that simulation curves and experimental curves of foot force are consistent. Rationality and feasibility of the center of mass calculation method is verified, and this method can be applied for other types of robots.