A Wireless Compact Control Unit (WiCCU) for Untethered Pneumatic Soft Robots

Abstract

The performance of a soft pneumatic robot (SPR) relies on the synergy between the mechanical design and the control unit that implements a closed-loop control between sensors and actuators. Most controllers are designed by using off-the-shelf components. Although commercial parts present high precision and reliability, they are heavy and bulky, limiting the realisation and design of untethered robots. The present study describes a wireless pneumatic control unit of a compact and light design that can control up to 3 pneumatic chambers. The unit includes pressure sensors and high precision miniaturised proportional valves. To simplify both the electrical cabling and the air tubes connections, a compact manifold is used to connect valves and pressure sensors. The control unit uses a Bluetooth RS232 serial module for a wireless communication. The mechatronic design is reported describing the electronic hardware, the manifold solution, and the firmware implementation. Experiments report i) the control of a linear pneumatic actuator (LPA), and ii) a simultaneous activation of 3 LPAs connected to a base providing 3 degrees of freedom (DOFs).