Contact-Aware Controller Design for Complementarity Systems

TL;DR

This paper introduces a novel control framework for multi-contact robotic systems that leverages tactile sensor data and complementarity dynamics to enable stable, real-time control without combinatorial complexity.

Contribution

It presents a non-combinatoric, optimization-based control method exploiting contact complementarity, allowing for stable, real-time multi-contact control using tactile sensors.

Findings

Successfully applied to three different underactuated robots.

Achieved provably stable control policies.

Demonstrated robustness and real-time capability.

Abstract

While many robotic tasks, like manipulation and locomotion, are fundamentally based in making and breaking contact with the environment, state-of-the-art control policies struggle to deal with the hybrid nature of multi-contact motion. Such controllers often rely heavily upon heuristics or, due to the combinatoric structure in the dynamics, are unsuitable for real-time control. Principled deployment of tactile sensors offers a promising mechanism for stable and robust control, but modern approaches often use this data in an ad hoc manner, for instance to guide guarded moves. In this work, by exploiting the complementarity structure of contact dynamics, we propose a control framework which can close the loop on rich, tactile sensors. Critically, this framework is non-combinatoric, enabling optimization algorithms to automatically synthesize provably stable control policies. We demonstrate this approach on three different underactuated, multi-contact robotics problems.