Fluid Control System for Hydraulic Actuated Textile
Soft actuators powered by fluid pressure have become a popular research topic in recent years. These actuators are capable of contracting, elongating, and bending. Among these movements, contracting is of the most interest. Due to the highly extensible and lightweight features, soft actuators have many potential applications in the field of wearable robotics. Our research has been dedicating to the design, fabrication, and control of the hydraulic actuated textile. As the research becomes more matured, we are seeking a hydraulic control system that is specifically designed for controlling these textiles. Thus, I present the design, test, and implementation of a fluid control system, along with the physical prototype product: The Fluid Control Box. Instead of using a syringe, which has a limited small volume, this Fluid Control Box uses a diaphragm pump as the pressure source and pumps unlimited volume of water into the textiles. Difference control method (On- off, Proportional, PID) are evaluated and PID (Proportional, Integral, Derivative) is proven to be the most efficient one. By incorporating with the PID control algorithm, the system is able to provide a precise and stable water pressure for multiple hydraulic actuated textiles. Different coefficient of the PID values are investigated and the optimum set is found. Experiments results that the fluid control box can control the fluid pressure accurately to achieve motion control of the textile actuators. To control more complicated movement in the future, we will design a method to simultaneously supplying different pressure to multiple textiles by using one pump.