Research on a high-accuracy and high-pressure pneumatic servo valve with aerostatic bearing for precision control systems

Autor: Chuan Wu, Dijia Zhang, Baoren Li, Longlong Gao, Xiaoyun Fu
Rok vydání: 2019
Předmět:
Zdroj: Precision Engineering. 60:355-367
ISSN: 0141-6359
Popis: In this paper, a novel single-stage high-pressure electro-pneumatic servo valve (HESV) directly driven by a voice coil motor (VCM) is proposed for a precision control system. The HESV is a three-position three-way spool-type flow valve. As the friction force of the spool increases, the clearance between the spool and sleeve decreases. The aerostatic bearing is designed to reduce the friction wear and improve the motion sensitivity of the spool. A nonlinear mathematical model of the HESV is derived including the electromagnetic subsystem, dynamic force balance equation, and so on. Furthermore, considering the highly nonlinear steady gas flow force, a hybrid fuzzy logic PID controller with a disturbance observer (DOB) is adopted to improve the performance of the HESV. In this study, a numerical analysis and experiments are carried out, and their results indicate that the static friction force of the developed HESV decreases from 15 N to 4.4 N because of the aerostatic bearing. The developed HESV exhibits a strong anti-interference performance because of the hybrid controller with the DOB; the valve spool can be recovered to the original control position rapidly within 0.03 s. The position control accuracy of the novel HESV is greatly improved. Thus, the HESV can be applied to high-pressure pneumatic precision control systems.
Databáze: OpenAIRE
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