Design and Control of Continuum Manipulators With Pose Reconstruction Based on Feedforward Compensation

Existing continuum manipulators excel at operations because of their omnidirectional bending capabilities. However, their operational performance is constrained by the lack of torsional function along their backbone curves. This paper addresses this issue by proposing a pose reconstruction control strategy that has been successfully applied to tendon-driven continuum manipulators with specific structural designs. This strategy achieves high-precision pose control through bend-torsion decoupling. Additionally, we introduce a model-based backlash function to address the non-linear relationship between the end effector and the actuators and to improve positional and directional accuracy during pose reconstruction. By incorporating indirect rotational compensation and separating control variables, the proposed method enables the manipulator to perform torsional functions along its backbone curves while ensuring applicability to different structural configurations. Simulation and experimental results confirm the efficacy of the proposed method: indirect rotational compensation reduces positional and directional errors by 30.76% and 87.29%, respectively. These findings demonstrate that the proposed approach provides a robust solution for pose reconstruction and high-precision manipulation with continuum manipulators in minimally invasive surgery.