Robotic Forceps Driven by Extension Type Pneumatic Soft Actuator

Abstract

In this paper, a robotic forceps driven by pneumatic soft actuators is developed. The actuator consists of a soft tube made of silicone rubber covered with a metal spring. The spring acts to restrain expansion of the actuator in the radial direction during pressurization and to generate pulling force during depressurization. Furthermore, the use of the spring facilitates the manufacture of the actuator. The forceps has two degrees of freedom (Dof) which are tendon driven by four wires. Each wire is connected to the actuator via a crank shaft mechanism that converts pushing force to pulling force. An actuator is connected to the wire located at the center of the forceps for grasping. The bending angle of the forceps is estimated by using the pressure in the actuator. Therefore, the forceps is washable and sterilizable and is suitable for disposable use because the sensors are not placed on the forceps. The position control performance of the forceps is confirmed experimentally by comparing with a non-contact sensor.