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

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.