Design and Control of a Multiple-Section Continuum Robot With a Hybrid Sensing System

Fang, Yihua; Dong, Xin; Mohammad, Abd; Axinte, Dragos

Abstract

After decades of development, the technology of continuum robots continues to mature gradually and is used for various applications, e.g., inspection and repair in high-value-added industries such as aerospace & nuclear. However, such robots are invariably designed with a hyper-redundant structure which causes condition-dependent uncertainties and errors in practical operations. In this work, a hybrid sensing solution-consisting of a dual displacement sensor system (linear & rotary encoders) and a self-carried visual tracking system-is presented to improve the control performance of a multi-section cable-driven continuum robot. The dual displacement sensor system works to measure the cable-displacement error at the proximal end of the arm and predicts the cable elongation in the arm to eliminate the control error of the robot in joint-space via a new two-stage cable-displacement control approach. Simultaneously, the self-carried visual system provides real-time section-by-section tip tracking to improve the controllability of the arm in the task space. This feedback is then integrated with a two-level closed-loop controller to achieve accurate tip-positioning control. A series of validation experiments are carried out to validate the approach. Compared with an off-the-shelf position tracking system (VICON), the measurement error of the proposed self-carried visual tracking system is smaller than 2 mm, with a mean error of 0.67 mm, within the work-space of a single-section continuum robot. The distal-tip control accuracy of a 2-section robot can achieve 1.72 mm under the closed-loop controller supported by the hybrid sensing system.

Citation

Fang, Y., Dong, X., Mohammad, A., & Axinte, D. (2023). Design and Control of a Multiple-Section Continuum Robot With a Hybrid Sensing System. IEEE/ASME Transactions on Mechatronics, 28(3), 1522-1533. https://doi.org/10.1109/TMECH.2022.3229188

• Journal Article Type: Article
• Acceptance Date: Dec 4, 2022
• Online Publication Date: Jan 9, 2023
• Publication Date: 2023-06
• Deposit Date: Apr 26, 2023
• Publicly Available Date: May 3, 2023
• Print ISSN: 1083-4435
• Electronic ISSN: 1941-014X
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 3
• Pages: 1522-1533
• DOI: https://doi.org/10.1109/TMECH.2022.3229188
• Keywords: continuum robot; closed-loop control; visual tracking; tip-positioning
• Public URL: https://nottingham-repository.worktribe.com/output/20001577
• Publisher URL: https://ieeexplore.ieee.org/document/10012271