Hybrid position–compliance control for selective stiffening and softening in soft continuum robots
File(s)
Accepted version
Author(s)
Zhou, Danni
Shi, Jialei
Type
Journal Article
Abstract
Due to inherent compliance and flexibility, soft robots are well suited for tasks in unstructured environments that require safe interaction. However, this compliance also limits robot’s payload capacity, highlighting the need for effective on-demand compliance regulation. This article develops and validates a real-time position-compliance control approach (exceeding 2 kHz) for pneumatic soft continuum robots, enabling both position–compliance stiffening and softening based on a quasi-static Cosserat rod model. The proposed approach is experimentally validated in three scenarios: first position and compliance-stiffening control for path following under external disturbances, second position and compliance-softening control for obstacle avoidance, and finally, significance of selective compliance regulation. Overall, the proposed method enables selective softening for safe interaction and stiffening for path following under external loads, without relying on additional variable-stiffness mechanisms. Results highlight the importance of on-demand stiffening and softening control for enhancing robot–environment interaction capabilities.
Date Issued
2026-07-22
Date Acceptance
2026-06-27
Citation
IEEE/ASME Transactions on Mechatronics, 2026
ISSN
1083-4435
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Journal / Book Title
IEEE/ASME Transactions on Mechatronics
Copyright Statement
Copyright © 2026 IEEE. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published online
Date Publish Online
2026-07-22