Quadruped Walking Algorithm Integrating Balance Control Using Cartinverted Pendulum Model and Optimization-based Whole-body Inverse Dynamics Control

This paper presents a walking strategy that enables stable locomotion on irregular ground and allows a quadruped robot to respond to external impact disturbances while walking. Initially, we designed a cart inverted pendulum model (CIPM) for dynamic control of the quadruped robot and converted the control commands derived from the LQR controller into ground reaction forces for balance control using quadratic programming (QP). Next, the derived ground reaction forces were converted into optimal joint torques that integrated the cost function and ground friction conditions through Whole-Body Inverse Dynamics Control (WBIDC) using a floating base dynamic model to realize the stable walking of the robot. To verify the algorithm, ground obstacles and an impact disturbance applicator were modeled on the walking path in the GAZEBO simulation environment, demonstrating successful performance of the quadruped robot walking algorithm presented in this paper.