PRESSURE CONTROL CHARACTERISTICS OF ELECTRO-PNEUMATIC REGULATOR WITH TWO MULTILAYERED PZT VALVES

This paper presents pressure control method using the electro-pneumatic regulator with two multilayered PZT valves. An electro-pneumatic regulator is a type of pressure control valve that is a combination of a poppet valve for main pressure control, two multilayered PZT valves for pilot pressure control, a microprocessor with a feedback controller and a pressure sensor. The benefits of bender type PZT actuator are faster response times, low energy consumption, and the ability to be used in hazardous environments and field bus systems. Solenoid actuator for electro-pneumatic regulator is widely used but this actuator has a high power consumption characteristics. So PZT actuator is required for the energy saving. In this study, a multilayered bender type PZT actuator of 27.0 mm(L)×9.0 mm(W)×0.8 (mm) with a constant of 220e-12 m/V and 20 sheets of PZT thin film was fabricated and experimented. The experiments for On-Off control and PID-PWM control of the electro-pneumatic regulator were operated under the input condition of 0.5 MPa. From the experiments, the performance characteristics of the fabricated electro-pneumatic regulator were evaluated. A new control method for precise proportional pressure control using the electro-pneumatic regulator with two PZT valves was suggested. Using this suggested model, all possible operating conditions were analyzed