Shape Sensing of Continuum Manipulators With Fiber Bragg Grating Sensor Arrays: Accounting for Actuator Velocity Effects

Tracking and controlling the shape of continuum dexterous manipulators (CDMs) in real time during nonconstant curvature bending and straightening is still a challenging task. This study introduces a velocity-dependent shape reconstruction model using fiber Bragg grating (FBG) sensors, addressing velocity-dependent curvature discrepancies caused by the sensing unit sliding within the manipulator’s channel. By incorporating these effects, the proposed model improves shape tracking accuracy across different velocities. Experimental validation in free and constrained environments at actuator velocities of 0.2, 0.8, and 1.4 mm/sec for positive and negative deflections demonstrated that the velocity-dependent model improves shape and tip tracking accuracy by 22%–65% compared to the conventional model. Results show significant reduction in shape and tip deviations, making the model suitable for flexible surgical instruments.