Parameter Identification and Modeling of a Pneumatic Proportional Valve with Applicability in Control Design of Servo-Pneumatic Systems

Abstract

The key element in a servo-pneumatic actuation system is the control valve. This paper presents a method for parameter identification and modeling the flow characteristic of a FESTO MPYE-5-1/8-HF-101B proportional valve. An experimental setup and a procedure for parameter identification is presented in the paper. Simulation and experimental results are in agreement and the model of the valve could be used in high-accuracy positioning control design of pneumatic servo-systems.

A new compressible flow model for pneumatic directional control valves

“…Furthermore, there is no exact information about the value specification of critical pressure ratio since the value of this parameter changes from valve to valve, even between the same type of valves. In other words, Harris et al 19 suggested the value of b as b = 0.23 whereas Van der Merwe et al, 21 Rad et al 22 and Rad and Hancu 23 all propose the value of b as a function of control signal ( b = f( u )). The parabolic change in the “ ii .…”

“…The parameters b and C are already presented in the manufacturer’s catalog. The discharge coefficient ( C d ) can also be determined by the relevant formulations as shown in detail in the study by Rad et al 22 These values can be useful when the standard or the improved flow models are utilized. However, there will be no need to use these pre-defined parameter values in the proposed model since the effect of these parameters will be expressed by the model parameters (i.e.…”

“…Consequently, the standard model was updated and the improved flow model, which produces more accurate outputs, was suggested in subsequent investigations. 18–23…”

“…22,23 The CPR value is mostly assumed as a = 1 in both models. 13–23 This implies that the flow continues until the pressure on the inlet and outlet side of the valve is equal. However, it is reported by Van Der Merwe et al 21 and Rad and Hancu 23 that the CPR was not equal to 1 ( a = 1) for all operating conditions of the valve.…”

“…Consequently, the standard model was updated and the improved flow model, which produces more accurate outputs, was suggested in subsequent investigations. [18][19][20][21][22][23] One of the common and important parameters for these two models is the cracking pressure ratio (CPR), which defines the ratio of the downstream pressure to the upstream pressure at the valve for which there is no flow due to pressure difference. 22,23 The CPR value is mostly assumed as a = 1 in both models.…”