Outer-Loop Admittance And Motion Control Dual Improvement via A Multi-function Observer
Safe environment contact and high performance motion control are typically conflicting design goals. Admittance control can improve safety and stability in contact with a stiff environment, but remains challenging on industrial robots.
Typically high-performance motion control is achieved by low-admittance systems, which can give high transient forces or instability in contact with high-stiffness environments.
This paper proposes a linear admittance control framework from which a Multi-function OBserver (MOB)-based control scheme that succeeds in directly improving the motion control accuracy by suppressing disturbances, while achieving better loop shaping in the outer-loop admittance control is developed.
By using the task space force and position measurement of the robot, combined with linearized robot and payload models to design the MOB, the outer-loop controller can render improved interactive dynamics.
In addition, a methodology to design the proposed MOB based on the reduced-order model is developed.
Theoretical evaluations and experiments verify the effectiveness of the proposed MOB-based control method, in contact with an environment stiffness and with a 7~kg payload.
European Union's Horizon 2020 research and innovation programme under grant agreement No 820689 — SHERLOCK
The National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2019R1A2C2011444)
Email Address of Submitting Authorksamuel27@dgist.ac.kr
ORCID of Submitting Author0000000277913356
Submitting Author's InstitutionDGIST
Submitting Author's Country
- Korea, Republic of (South Korea)