Movement Environment Assessment and Force Prediction for Quadruped Robots

Assessing the operating environment of a quadruped robot and analyzing the forces acting on its footpads are crucial for enhancing motion stability and enabling effective path planning, ultimately ensuring successful task completion. This study focuses on analyzing the robot's motion state and its contact process to better understand its contact dynamics and develop a comprehensive dynamic model. The model defines the relationship between footpad forces and joint angular torque, enabling both environmental assessment and force prediction. Experimental validation was conducted using the quadruped robot in various environments, confirming the model's effectiveness. By comparing the joint angular torque during contact and noncontact states, the footpad contact conditions were determined. During the contact phase, joint angular torque exceeded the noncontact torque, with greater discrepancies corresponding to higher footpad forces. These findings suggest that denser soil improves the robot's performance. The method for calculating footpad forces from torque demonstrated accuracy exceeding 90%, highlighting its precision. These results provide valuable insights for calculating operational forces, as well as for the stability assessment and trajectory planning of quadruped robots.