Design and Control of Soft Pneumatic Actuator with Embedded Flexion Sensor

Soft robotics has been widely explored in the past decade due to their ability to adapt to different environments and interact softly with external objects. This paper presents the design, manufacture, model identification and control of a low cost soft robotic pneumatic actuator with sensing capabilities, the proposed actuator has potential application in prosthetic and orthotic devices. Initially, the design and fabrication of the actuator is presented, including the design parameters and manufacturing techniques. The system was modeled using system identification techniques allowing to implement a PI controller to control the actuator deformation. In addition, the design and fabrication of a soft bending sensor, based on a variable resistance material, was presented. The sensor was used as feedback element for the control system and allowed to control the deformation of the actuator. The soft actuator only requires 0.4 bar of pressure to achieve maximum deformation; the controlled actuator achieved a settling time of 4.5 s and an steady state error of 2 %.