This work proposes a novel impedance control strategy for a delayed bilateral tele-surgery system to perform a drilling process during spinal surgery. In the new designed control scheme, regarding a desired impedance model for master and slave robot, an especial dynamic characteristic at the surgeon and master as well as slave and vertebra interface is designed. Two desired impedance models are proposed for the master and slave robots such that: (a) the salve robot that holds the drilling device should track the master path but complies with the reaction force of the vertebra, and (b) the surgeon should receive feedback from the slave-vertebra interaction force via the master robot. These main objectives are attained by proper adjustment in the proposed impedance model, which does not require any direct measurement of vertebra reflections. Then, the impedance model is put into a proper sliding mode controller to cope with the modeling uncertainties in the slave side. Consequently, the absolute stability concept is utilized to investigate closed-loop system stability and transparency. Finally, the control scheme is implemented on one degree of freedom robotic manipulators as master and slave robot. Experimental results demonstrate the efficiency of the designed impedance control scheme in the presence of modeling uncertainties.

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