Towards High-Payload Admittance Control for Manual Guidance with Environmental Contact

TL;DR

This paper develops and validates new control and design methods to enable high-payload robots to perform manual guidance and contact-rich tasks safely and effectively, extending compliance control techniques to heavier industrial robots.

Contribution

It introduces novel mechatronic design methods, including extended admittance control with damping feedback, compliant environmental structures, and continuous contact response, tailored for high-payload robot applications.

Findings

Methods achieve stable contact and free-space operation on 16 kg payloads.

Successful execution of peg-in-hole and slot assembly tasks.

Demonstrated free-space co-manipulation with a 50 kg payload.

Abstract

Force control enables hands-on teaching and physical collaboration, with the potential to improve ergonomics and flexibility of automation. Established methods for the design of compliance, impedance control, and \rev{collision response} can achieve free-space stability and acceptable peak contact force on lightweight, lower payload robots. Scaling collaboration to higher payloads can allow new applications, but introduces challenges due to the more significant payload dynamics and the use of higher-payload industrial robots. To achieve high-payload manual guidance with contact, this paper proposes and validates new mechatronic design methods: standard admittance control is extended with damping feedback, compliant structures are integrated to the environment, and a contact response method which allows continuous admittance control is proposed. These methods are compared with respect to free-space stability, contact stability, and peak contact force. The resulting methods are then applied to realize two contact-rich tasks on a 16 kg payload (peg in hole and slot assembly) and free-space co-manipulation of a 50 kg payload.