Study on Electro Hydraulic Force Servo System Considering Spool Friction and Cylinder Piston Friction Nonlinear

The flow press servo valve has very special work principle, and it now is widely used in the electro-hydraulic force servo system as main and kernel part. According to its special work principle, electromagnetic basic theory and the flow continuity equation, the mechanics analysis of every main part of the flow press servo valve was finished; the author built the mathematic model of the flow press sever valve. During the process of building model, the author took into account the load torque on the torque motor keeper and the total load torque of torque motor. On the other hand, the neural network intelligent control strategy was used in the force servo system to improve the whole system performance. The mathematic model of the electro-hydraulic force servo system controlled by the flow press servo valve with the neural network control strategy was built. The simulation curves and the experiment curves were accord compared by system simulation and experiment results, so we can know also that the mathematic model of the flow press sever valve and the electro-hydraulic force servo system controlled by this kind of valve with the neural network intelligent control strategy are correct.

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Disturbance Rejection Control of Industrial Heavy-load Hydraulic Force Servo System

ACTA AUTOMATICA SINICA ◽

10.3724/sp.j.1004.2009.00926 ◽

2009 ◽

Vol 35 (7) ◽

pp. 926-932 ◽

Cited By ~ 1

Author(s):

Bo YANG ◽

Wan-Zhou LI ◽

Zhao-Fang JIANG ◽

Tong-Gang SHI ◽

Guan-Yuan WU ◽

...

Keyword(s):

Disturbance Rejection ◽

Servo System ◽

Heavy Load ◽

Hydraulic Force ◽

Disturbance Rejection Control

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A versatile hydraulically operated respiratory servo system for ventilation and lung function testing

Journal of Applied Physiology ◽

10.1152/jappl.1983.55.3.1023 ◽

1983 ◽

Vol 55 (3) ◽

pp. 1023-1030 ◽

Cited By ~ 16

Author(s):

M. Meyer ◽

H. Slama

Keyword(s):

Lung Function ◽

Gas Flow ◽

Servo System ◽

Test Procedures ◽

Respiratory Parameters ◽

Cylinder Piston ◽

Point Control ◽

And Performance ◽

End Tidal ◽

Function Testing

A description is given of the design and performance of a microcomputer-controlled respiratory servo system that incorporates the characteristics of a mechanical ventilator and also allows the performance of a multitude of test procedures required for assessment of pulmonary function in paralyzed animals. The device consists of a hydraulically operated cylinder-piston assembly and solenoid valves that direct inspiratory and expiratory gas flow and also enable switching to different test gas sources. The system operates as a volume-flow-preset ventilator but may be switched to other operational cycling modes. Gas flow rates may be constant or variable. The system operates as an assister-controller and, combined with a gas analyzer, can function as a “demand” ventilator allowing for set-point control of end-tidal PCO2 and PO2. Complex breathing maneuvers for a variety of single- and multiple-breath lung function tests are automatically performed. Because of the flexibility in selection and timing of respiratory parameters, the system is particularly suitable for respiratory gas studies.

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