Eye-in-Hand Visual Servoing of Concentric Tube Robots
IEEE Robotics & Automation Letters, 3(3):2315-2321, t = This letter deals with the development of a vision-based controller for a continuum robot architecture. More precisely the controlled robotic structure is based on three-tube concentric tube robot (CTR) an emerging paradigm to design accurate miniaturized and flexible endoscopic robots. This approach has grown considerably in the recent years finding applications in numerous surgical disciplines. In contrast to conventional robotic structures CTR kinematics arise many challenges for an optimal control such as friction torsion shear and nonlinear constitutive behavior. In fact in order to ensure efficient and reliable control in addition to computing an analytical and complete kinematic model it is also important to close the control loop. To do this we developed an eye-in-hand visual servoing scheme using a millimeter-sized camera embedded at the robot's tip. Both the kinematic model and the visual servoing controller were successfully validated in simulation with visual servoing platform and using an experimental setup. The obtained results showed satisfactory performances for three-degrees of freedom positioning and path following tasks with adaptive gain control.