Flexible Interactive Control for Robot-Assisted Orthopedic Procedures

Balancing operational transparency with dynamic stability remains a critical challenge in robotic-assisted surgery. This paper proposes a flexible adaptive admittance control strategy based on interaction force feedback to meet the multi-scale task requirements of surgical procedures. By employing interaction force as a comprehensive index of the surgeon's intent, a nonlinear mapping law based on the Sigmoid function is established to achieve continuous and stable transitions of damping coefficients. The integration of an adaptive Butterworth filter and nonlinear saturation constraints further ensure force signal fidelity and system safety. Experimental results on the orthopedic robot demonstrate that the strategy accurately adjusts dynamic responses according to real-time energy characteristics. Compared with the conventional fixed high-damping mode, the proposed method can suppress the tremor phenomenon during precise operation effectively, and can significantly reduce the operation resistance when conducting large-workspace movement.