Shape-Reconstruction-Based Force Sensing Method for Continuum Surgical Robots With Large Deformation

Continuum robots have been attracting extensive attentions in the past few years due to their potential applications in minimally invasive surgery (MIS). Force sensing is critical in surgical applications which require palpation or deal with delicate structures. This letter addresses on the force sensing issue of surgery continuum robots. We propose a new force sensing method based on the shape reconstruction algorithm and the robot kinematic-static model. This method only requires the pose of the robot tip and the tensions of the driving cables. Experiments and simulations are carried out to validate the proposed force sensing method, and analyze the resolution and accuracy. Results showthat both accuracy and resolution depend on the robot deflection angle. For 24 groups of tests, where the robot deflection angles are within 95 degrees, the average sensing error is 3.1% with a maximum value of 7.1%, and the average resolution is +/- 0.19 g with a maximum value of +/- 0.57 g. Therefore, the proposed force sensingmethod is feasible to provide force information for MIS operations.