Development of Pneumatic Networks Soft Robot with Anti-Windup PID Control

Abstract

Soft robots are different compared to conventional robot in the use of soft and flexible body instead of joint to actuate. In this paper, a soft robot system was developed including the actuator, feedback, and control system. Pneumatic networks, a soft body that composed of chambers, was created, and used as the actuator for the system. The soft body consist of extensible and inextensible layer that need pneumatic pressure to actuate in the manner of bending at one direction. A closed loop system was designed to control the pneumatic system by using a programmable air pump and feedback from a pressure sensor. This system provides and regulate the pressure needed in the system. System identification technique was used to model the actuator pressure in the linear region. Based on the model derived, a PID controller with anti-windup compensation were implemented to control the pressure in the linear region. The performance of the controller was evaluated by tracking the result for various input. The result shows the designed controller capable at tracking the pressure reference at the linear region with less than 5 seconds settling time but unstable at pressure below 4.5 kPa.