Adaptive Control of a Proportional Flow Valve for Critical Care Ventilators

2018 ◽  
Author(s):  
Mike Borrello
Keyword(s):  
Critical Care ◽  
Adaptive Control ◽  
Proportional Flow ◽  
Flow Valve

A Novel Control Strategy for Pilot Controlled Proportional Flow Valve With Internal Displacement-Flow Feedback

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
He Wang ◽  
Xiaohu Wang ◽  
Jiahai Huang ◽  
Jun Wang ◽  
Long Quan
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Control Strategy ◽  
Pid Controller ◽  
Back Propagation ◽  
Back Propagation Neural Network ◽  
Internal Displacement ◽  
Valve Opening ◽  
Proportional Flow ◽  
Flow Valve

The present study is focused on the construction of a well-performing pilot controlled proportional flow valve with internal displacement-flow feedback. A novel control strategy for the valve is proposed in which the flow rate through the valve is directly controlled. The linear mathematical model for the valve is established and a fuzzy proportional–integral–derivative (PID) controller is designed for the flow control. In order to obtain the flow rate used as feedback rapidly and accurately in real-time, back propagation neural network (BPNN) is employed to predict the flow rate through the valve with the pressure drop through the main orifice and main valve opening, and the predicted value is used as the feedback. Both simulation and experimental results show that the predicted value obtained by BPNN is reliable and available for the feedback. The proposed control strategy is effective with which the flow rate through the valve remains almost constant when the pressure drop through the main orifice increases and the valve can be applied to the conditions where the independence of flow rate and load is required. For the valve with the proposed control strategy, the nonlinearity is less than 5.3%, the hysteresis is less than 4.2%, and the bandwidth is about 16 Hz. The static and dynamic characteristics are reasonable and acceptable.

Simulation and Experimental Research of Hydraulic Actuator for Automatic Transmission

2013 ◽  
Vol 753-755 ◽  
pp. 1050-1053
Author(s):  
Yong Dao Song ◽  
Xiu Sheng Cheng ◽  
Qiang Gu ◽  
Hua Bin Hu
Keyword(s):  
Predictive Control ◽  
Experimental Research ◽  
Intelligent Control ◽  
Control Algorithm ◽  
Automatic Transmission ◽  
Hydraulic Actuator ◽  
Adaptive Ability ◽  
Actuator Control ◽  
Proportional Flow ◽  
Flow Valve

The accurate control of hydraulic actuator is critical for automatic transmission to launch or shift smoothly. The mathematical and simulation model of proportional flow valve based on Matlab/Simulink were established , and hydraulic actuator control arithmetic based on NNPC(Neuro Network Predictive Control) was introduced to realize accurate control of clutch displacement. The experiment was carried out and the rusults showed that the model of proportional flow valve was correct and hydraulic actuator intelligent control algorithm based on NNPC had good adaptive ability and high precision.

Research on the performance of electro-hydraulic proportional flow valve controlled by active pilot pump

2016 ◽  
Vol 231 (4) ◽  
pp. 720-731 ◽  
Author(s):  
Yunxiao Hao ◽  
Long Quan ◽  
Jiahai Huang
Keyword(s):  
Pressure Differential ◽  
Small Displacement ◽  
Flow Pulsation ◽  
Pump Speed ◽  
Pump Flow ◽  
Flow Capacity ◽  
Flow Through ◽  
Large Flow ◽  
Proportional Flow ◽  
Flow Valve

The cartridge flow valves, used in heavy machine and equipment, have the advantages of low leakage, large flow capacity, simple structure, and ease of modulation. However, in order to reduce the influence of load variety on the flow through valve, a pressure differential compensator or a cartridge type flow sensor should be added to the proportional throttle valve. These methods have disadvantages of reducing the flow capacity of valve and increasing the throttling loss. To overcome these disadvantages, a low energy consumption, high controllable electro-hydraulic proportional flow valve which consists of a hydraulic transistor (Valvistor) and a small displacement hydraulic pump driven by a servo motor is proposed firstly in the world. As the pump flow is basically proportional to the pump speed and little influenced by load variety, the flow through main valve is proportional to pilot pump speed. In the research, it’s known that feedback throttle slot pre-opening will cause the decrease of the main valve flow as pressure drop increases. So, small orifices are used instead of the pre-opening of feedback throttle slot to reduce the influence of load variety on the flow through valve. Furthermore, a method of pressure differential changing with pilot pump rotational speed calibration is introduced to further mitigate the influence of pressure difference. In this paper, the mathematical dynamic model of the valve is also established and the stability criterion of valve is derived. The influence of valve parameters and the flow pulsation of pilot pump on valve flow performance is analyzed and simulated. In view of the pilot pump flow pulsation frequency being much higher than the valve natural frequency, the research shows that the influence of flow pulsation of pilot pump on valve flow performance is very little. The research work provides a new method for the large flow electro-hydraulic proportional control system.

scholarly journals The simulation analysis for cartridge proportional flow valve

2016 ◽  
Vol 77 ◽  
pp. 02009
Author(s):  
Peng Dong ◽  
Shengdun Zhao ◽  
Yuanzhe Dong ◽  
Shuqin Fan
Keyword(s):  
Simulation Analysis ◽  
Proportional Flow ◽  
Flow Valve

Electro-Hydraulic Proportional Flow Valve Control Complex Variable Pump and Research its Property for Injection Machine Hydraulic System

2012 ◽  
Vol 591-593 ◽  
pp. 2148-2151
Author(s):  
Lan Li ◽  
Xue Fei Zheng ◽  
Xian Bo Xie
Keyword(s):  
Complex Variable ◽  
Hydraulic System ◽  
Pump Efficiency ◽  
Output Flow ◽  
Pump Output ◽  
Working Principle ◽  
Valve Control ◽  
Control Complex ◽  
Proportional Flow ◽  
Flow Valve

In hydraulic system of injection machine, electro-hydraulic proportional flow valve is used to change complex variable pump output flow and power in order to adapt to load change and energy saving.In this paper ,it introduces the working principle of electro-hydraulic proportional flow valve and how control the complex variable pump. Mathematical modeling of proportional flow valve is built and simulations based on Matlabsimulink software is done. It analyses dynamic characteristics of complex variable pump in different electricity. The results are helpful in improving the pump efficiency and response,and they provide theoretical basis for energy saving.

scholarly journals Design of pneumatic proportional flow valve type 5/3

2017 ◽  
Vol 233 ◽  
pp. 012029 ◽  
Author(s):  
P A Laski ◽  
D S Pietrala ◽  
J Zwierzchowski ◽  
K Czarnogorski
Keyword(s):  
Proportional Flow ◽  
Flow Valve

scholarly journals Flow Control for a Two-Stage Proportional Valve with Hydraulic Position Feedback

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
He Wang ◽  
Xiaohu Wang ◽  
Jiahai Huang ◽  
Long Quan
Keyword(s):  
Mathematical Model ◽  
Flow Control ◽  
Control Method ◽  
Two Stage ◽  
Proportional Valve ◽  
Load Pressure ◽  
Flow Fluctuation ◽  
Position Feedback ◽  
Proportional Flow ◽  
Flow Valve

AbstractThe current research mainly focuses on the flow control for the two-stage proportional valve with hydraulic position feedback which is named as Valvistor valve. Essentially, the Valvistor valve is a proportional throttle valve and the flow fluctuates with the change of load pressure. The flow fluctuation severely restricts the application of the Valvistor valve. In this paper, a novel flow control method the Valvistor valve is provided to suppress the flow fluctuation and develop a high performance proportional flow valve. The mathematical model of this valve is established and linearized. Fuzzy proportional-integral-derivative (PID) controller is adopted in the closed-loop flow control system. The feedback is obtained by the flow inference with back-propagation neural network (BPNN) based on the spool displacement in the pilot stage and the pressure differential across the main orifice. The results show that inference with BPNN can obtain the flow data fast and accurately. With the flow control method, the flow can keep at the set point when the pressure differential across the main orifice changes. The flow control method is effective and the Valvistor valve changes from proportional throttle valve to proportional flow valve. For the developed proportional flow valve, the settling time of the flow is very short when the load pressure changes abruptly. The performances of hysteresis, linearity and bandwidth are in a high range. The linear mathematical model can be verified and the assumptions in the system modeling is reasonable.

Sign in / Sign up

Export Citation Format

Share Document