Variable Stiffness Model Construction and Simulation Verification of Coupled Notch Continuum Manipulator

The continuum manipulators, which have gradually become a research hotspot of minimally invasive surgery have the characteristics of small size, lightweight, and better environmental adaptability. In this paper, a two degrees of freedom continuum manipulator with notches is proposed. The kinematic and mechanical models of the notch continuum manipulator are coupled. The output driving force of the motor is needed to control the manipulator. Due to the drift of the current of the motor, the accuracy of the control is low. In order to solve the above problem, the constant curvature assumption is realized by changing the structural parameters of the notches. The continuum manipulator mechanics model is established through the analysis of the continuum manipulator structure. The calculation of the deformation angle of a single notch of the manipulator is carried out. The overall deformation of the manipulator is derived through iterative algorithms. The stiffness of the continuum manipulator, which can affect the deformation of the continuum manipulator is modified by changing the structural parameters. In this way, the problem of the non-constant curvature deformation under the uniform notch of the continuum manipulator is improved. And the effectiveness of the variable stiffness model is verified by simulation experiments.