Stable and Robust SLIP Model Control via Energy Conservation-Based Feedback Cancellation for Quadrupedal Applications

TL;DR

This paper introduces an energy-conservation based control method for quadruped robots modeled as SLIP, enabling stable and robust bouncing gaits with sensor error tolerance, inspired by biological locomotion.

Contribution

The paper proposes a novel energy-based control architecture for SLIP-modeled quadrupeds, improving stability and robustness in dynamic bouncing gaits.

Findings

Successfully generates stable bouncing gaits in simulation.

Maintains stability with up to 10% sensor measurement errors.

Demonstrates applicability to real quadruped robot design.

Abstract

In this paper, we present an energy-conservation based control architecture for stable dynamic motion in quadruped robots. We model the robot as a Spring-loaded Inverted Pendulum (SLIP), a model well-suited to represent the bouncing motion characteristic of running gaits observed in various biological quadrupeds and bio-inspired robotic systems. The model permits leg-orientation control during flight and leg-length control during stance, a design choice inspired by natural quadruped behaviors and prevalent in robotic quadruped systems. Our control algorithm uses the reduced-order SLIP dynamics of the quadruped to track a stable parabolic spline during stance, which is calculated using the principle of energy conservation. Through simulations based on the design specifications of an actual quadruped robot, Ghost Robotics Minitaur, we demonstrate that our control algorithm generates stable bouncing gaits. Additionally, we illustrate the robustness of our controller by showcasing its ability to maintain stable bouncing even when faced with up to a 10% error in sensor measurements.