Position Adjustment and Jumping Control of Quadruped Robot Based on VMC in Lunar Surface

This paper investigates the jumping control of a quadruped robot in the lunar surface. The objective of the control is to force the robot to jump onto the upper surface of a certain object. Faced with the situation that existing robot control algorithms rarely address how to achieve precise jumps in the Moon's low-gravity environment, this paper proposes an improved Virtual Model Control (VMC) method to enable quadruped robots to jump onto obstacle surfaces. The research and simulation focus on trajectory planning of the Center of Mass (CM), the posture adjustment and ejection phase of quadruped robots. Firstly, the Fastest Approaching Iterative Method (FAIM) is used to calculate the Optimal Parabolic Trajectory of CM(OPTC) when jumping onto an obstacle. This ensures that the quadruped robot avoids collisions while minimizing energy consumption during the jumping. Subsequently, enhancements are made to VMC method, and a six-dimensional space decoupling algorithm is employed to control the robot's posture adjustment and ejection phase. Furthermore, the spring and damping coefficients of the virtual spring-damper model are optimized to accommodate the lunar gravity environment. Finally, simulation experiments are conducted in the open-source software Webots. The results demonstrate that the quadruped jumping robot can follow the optimized trajectory to jump onto the obstacle surface, proving the feasibility and effectiveness of the algorithm in the lunar environment.