A prototype of pneumatically-driven forceps manipulator with force sensing capability using a simple flexible joint

This paper presents the first prototype of pneumatically-driven forceps manipulator using a simple flexible joint with intrinsic force sensing. A high performance spring component with wire actuation is employed for two-degree of freedom (DOF) bending joint, and two-DOF tendon drive system is implemented by four pneumatic cylinders. Using a continuum model for the kinematics, a PD controller with static and dynamic compensation is designed for the position control, which shows a good performance at the sufficient working frequency for surgical operations. The forceps manipulator can estimate external forces using a disturbance observer. A link approximation model is introduced to design the observer as the first intuitive approach. The force estimation can be achieved with an accuracy of 0.2 N in the basic straight posture.