Terrain Estimation with Least Squares and Virtual Model Control for Quadruped Robots

Abstract

Abstract In this paper, a method to estimate the terrain based on footholds and least-squares is presented to make quadrupedal locomotion stable on the sloped terrains, with joint encoders, force sensors and inertial measurement unit (IMU) instead of visual sensors. This method which is tested successfully in simulation can predict two types of terrain, one for adjusting the robot pose and the other for adjusting the trajectory of swing phase. And to make full use of these new capabilities, general balance and locomotion controller is presented. The virtual model controller is embedded into architecture and it allows the robot to handle unexpected terrain. The quadrupedal locomotion in terrain with different inclination prove the robustness of this method.