Towards High-Payload Admittance Control for Manual Guidance with Environmental Contact
This work addresses the problem of enabling physical collaboration and hands-on teaching for high-payload industrial robots, which is incremental as it extends existing admittance control methods.
The paper tackled the problem of scaling force control for manual guidance to higher-payload robots, which is challenging due to payload dynamics and industrial robot use, by proposing new mechatronic design methods including damping feedback, compliant structures, and continuous admittance control, and validated them on tasks with payloads up to 50 kg.
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.