Path Tracking Strategy for Quadruped Robots Using a Hierarchical Framework

摘要

We present a general path tracking strategy, with continuous gaits, for quadruped robots on flat and rigid terrain. We use a hierarchical framework to decompose the task into unique motion templates (actions) such as translation and turning. A Linear Inverted Pendulum Model (LIPM) based algorithm is applied to create physically correct actions while minimizing the sum of squared accelerations of the CoM. These actions are stored in an online action library and are combined using an autonomous steering system that decides when to use which action. The steering system also computes the input parameters for these actions. We also develop transition maneuvers to execute a smooth switching between these actions. This strategy can help reduce the repeated need to perform comprehensive online computation for motion planning. Moreover, one can enrich the action library to execute more complicated tasks involving different gaits and non-flat terrain. We use an 18 DoF quadruped robot model, and simulations are carried out in MATLAB to demonstrate the capabilities of this approach.