Fuzzy adaptive variable impedance control on deformable shield of defecation smart care robot

Abstract

Precise control of the contact force is crucial in the application of non-wearable defecation smart care (DSC) robot. A deformable shield equipped with a pressure sensing function is designed, with a bending angle that can be adjusted according to pressure feedback, thus enabling it to adapt to various body shapes. To improve the force tracking accuracy and prevent obvious force overshoot in the initial contact stage, a contact force control strategy based on fuzzy adaptive variable impedance is proposed. The proposed contact force control strategy achieves an average root-mean-square error of 0.024 and an average overshoot of 1.74%. Experimental results demonstrate that the designed deformable shield can fit the human body well, while the proposed control strategy enhances the contact force management and realizes the precise control of human-robot contact force.

Keywords

Defecation smart care robot / Deformable shield / Human-robot contact force / Fuzzy adaptive variable impedance controller

CRediT authorship contribution statement

Lingling Chen: Writing - review & editing, Resources, Project administration, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization. Pengyue Lai: Writing - original draft, Supervision, Software. Yanglong Wang: Validation. Yuxin Dong: Visualization.

Ethics approval

This work was approved by the Ethics Committee of Xuanwu Hospital, Capital Medical University (ChiCTR2400092918).

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work was supported by grants from the National Key R and D Program of China (2022YFB4703300).

Appendix A. Supplementary data

Supplementary material related to this article can be foundonline at https://doi.org/10.1016/j.birob.2025.100214.

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