US 12,436,549 B2
Flowrate control device, flowrate control method, and fluid supply system
Katsutoshi Sakai, Kawasaki (JP); and Yuki Fukuzawa, Kawasaki (JP)
Assigned to Shinwa Controls Co., Ltd., Kawasaki (JP)
Appl. No. 18/041,859
Filed by SHINWA CONTROLS CO., LTD, Kawasaki (JP)
PCT Filed Aug. 6, 2021, PCT No. PCT/JP2021/029257
§ 371(c)(1), (2) Date Feb. 16, 2023,
PCT Pub. No. WO2022/039047, PCT Pub. Date Feb. 24, 2022.
Claims priority of application No. 2020-140330 (JP), filed on Aug. 21, 2020.
Prior Publication US 2023/0333575 A1, Oct. 19, 2023
Int. Cl. G05B 11/42 (2006.01); G05D 7/06 (2006.01)
CPC G05D 7/0623 (2013.01) [G05B 11/42 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A flowrate control device that controls a flowrate of a fluid flowing out from a flowrate regulating valve by changing an opening degree of the flowrate regulating valve, the flowrate control device comprising:
a storing unit that stores opening degree characteristic of the flowrate regulating valve, the opening degree characteristic defining a relationship between the opening degree and a Capacity Factor (Cv) value of the flowrate regulating valve;
an inputting unit that inputs a target flowrate of the fluid flowing out from the flowrate regulating valve, and a flowrate change velocity to reach the target flowrate;
a detecting unit that detects, from when the control of the flowrate to the target flowrate is started, the flowrate of the fluid flowing out from the flowrate regulating valve at a predetermined cycle; and
an opening-degree regulating unit that determines a difference between the detected flowrate detected by the detecting unit and a planned flowrate in the course of achieving the target flowrate, wherein the planned flowrate corresponding to the detected flowrate is defined by the flowrate change velocity and a number of detection executed by the detecting unit, and, when the difference is determined, calculates a regulated opening degree corresponding to the planned flowrate from the Cv value of the opening degree characteristic and regulates the opening degree of the flowrate regulating valve by feedback control that uses, as a target value, an opening-degree operation amount that is calculated based on an opening degree difference between the regulated opening degree and a current opening degree of the flowrate regulating valve.