Analysis of Rotary Direct Drive Electro-hydraulic Pressure Control Servo Valve

2018 ◽  
Vol 54 (16) ◽  
pp. 186 ◽  
Author(s):  
Jiayang YUAN
Keyword(s):  
Pressure Control ◽  
Hydraulic Pressure ◽  
Direct Drive ◽  
Servo Valve

Feasibility Study on the Use of a Voice Coil Motor Direct Drive Flow Rate Control Valve

2009 ◽  
Author(s):  
Shuai Wu ◽  
Richard Burton ◽  
Zongxia Jiao ◽  
Juntao Yu ◽  
Rongjie Kang
Keyword(s):  
Neural Network ◽  
Flow Control ◽  
Flow Rate ◽  
Rate Control ◽  
Network Flow ◽  
Voice Coil Motor ◽  
Direct Drive ◽  
Hydraulic Test ◽  
Servo Valve ◽  
Flow Rate Control

This paper considers the feasibility of a new type of voice coil motor direct drive flow control servo valve. The proposed servo valve controls the flow rate using only a direct measurement of the spool position. A neural network is used to estimate the flow rate based on the spool position, velocity and coil current. The estimated flow rate is fed back to a closed loop controller. The feasibility of the concept is established using simulation techniques only at this point. All results are validated by computer co-simulation using AMESim and Simulink. A simulated model of a VCM-DDV (Voice Coil Motor-Direct Drive Valve) and hydraulic test circuit are built in an AMESim environment. A virtual digital controller is developed in a Simulink environment in which the feedback signals are received from the AMESim model; the controller outputs are sent to the VCM-DDV model in AMESim (by interfacing between these two simulation packages). A LQR (Linear Quadratic Regulator) state feedback and nonlinear compensator controller for spool position tracking is considered as this is the first step for flow control. A flow rate control loop is subsequently included via a neural network flow rate estimator. Simulation results show that this method could control the flow rate to an acceptable degree of precision, but only at low frequencies. This kind of valve can find usage in open loop hydraulic velocity control in many industrial applications.

Hydraulic Pressure Control and Parameter Optimization of Brake-by-Wire System Based on Driver-Automation Cooperative Driving

2018 ◽  
Author(s):  
Xiaohui Liu ◽  
Liangyao Yu ◽  
Sheng Zheng ◽  
Jinghu Chang ◽  
Fei Li
Keyword(s):  
Parameter Optimization ◽  
Pressure Control ◽  
Intelligent Vehicle ◽  
Hydraulic Pressure ◽  
Braking Performance ◽  
Driving Mode ◽  
Automatic Driving ◽  
Cooperative Driving ◽  
Braking System ◽  
Wire System

The automatic driving technology of vehicle is being carried out in real road environment, however, the application of unmanned vehicle still needs proof and practice. Autonomous vehicles will be in the stage of co-drive for a long time, that is, driver-control and autonomous system assisting or autonomous system control and driver assisting. The braking system of the intelligent vehicle needs to work in driver driving mode or automatic driving mode during a long stage. Brake-by-Wire system is the development trend of vehicle braking system. The brake modes of the Brake-by-Wire system can be switched easily and it can satisfy the demand for braking system of the intelligent vehicle. However, when the driving mode changes, the characteristic of the braking intention and braking demand will change. In order to improve the braking performance of the intelligent vehicle, hydraulic pressure control and parameter optimization of the Brake-by-Wire system during different driving modes should be different. Researches are made on hydraulic pressure control and parameter optimization of the Brake-by-Wire system with consideration on differences of braking intensity input and braking requirement between driver driving mode and automatic driving mode through theory analysis, Matlab/Simulink-AMESim simulation and bench test. The study is helpful for improving the braking performance of Brake-by-Wire system in hydraulic pressure control of driver-automation cooperative driving.

scholarly journals Stable Switching Control Strategy of the Support Pressure and Velocity of Shield Machine Gripper Shoes

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Nannan Liu ◽  
Jishen Peng ◽  
Liye Song ◽  
Pinhe Wang ◽  
Kun Zhang
Keyword(s):  
Position Control ◽  
Control Method ◽  
Control Strategies ◽  
Pressure Control ◽  
Surrounding Rock ◽  
Support Pressure ◽  
Hydraulic Pressure ◽  
Compound Control ◽  
Hydraulic Servo ◽  
Shield Machine

An electro-hydraulic servo position and pressure compound control method was investigated considering the working principle of a hydraulic stepping motor of a shield machine gripper shoe and its practical working characteristics in the supporting process. The control targets were to improve the support efficiency and reduce the disturbance of gripper shoes on the surrounding rock. In this method, a fuzzy switching controller was used to switch between electro-hydraulic position control and electro-hydraulic pressure control. Numerical and prototype simulation experiments were conducted on the control method. The theoretical analysis and experimental results showed that the control method could effectively convert the gripper shoes from an unsupported state to a supported state in a short amount of time, as well as realize surge-free switching between position control and pressure control. Thus, disturbance of the gripper shoes on the surrounding rock could be reduced. The results of this study provide a theoretical basis for research on control strategies of hydraulic stepping propulsion of shield machines.

A programmable pressure control system for coronary flow studies

1982 ◽  
Vol 243 (5) ◽  
pp. H796-H802 ◽  
Author(s):  
J. M. Canty ◽  
R. E. Mates
Keyword(s):  
Frequency Response ◽  
Coronary Flow ◽  
Closed Loop ◽  
Pressure Control ◽  
Circumflex Coronary Artery ◽  
Servo Valve ◽  
Coronary Pressure ◽  
Pressure Control System ◽  
Frequency Components ◽  
Flow Waveforms

An electrohydraulic servo valve capable of reproducing phasic physiological pressure and flow waveforms has been designed and constructed. The device has been utilized successfully in canine coronary flow studies. By measuring coronary pressure directly it is possible to reproduce waveform frequency components as high as 50 Hz in the cannulated left circumflex coronary artery when operated in a negative feedback configuration. It may easily be adapted to operate in a pressure- or flow-controlled mode in any vascular bed. The closed-loop frequency response of the servo valve itself is flat to 100 Hz with a natural frequency of 170 Hz. When utilized in the cannulated bed the frequency response is dependent on perfusion circuit and catheter dynamics.

scholarly journals RENOVATION OF NMIJ'S 5 MN HYDRAULIC AMPLIFICATION TYPE FORCE STANDARD MACHINE

2013 ◽  
Vol 24 ◽  
pp. 1360011
Author(s):  
TOSHIYUKI HAYASHI ◽  
HIROSHI MAEJIMA ◽  
KAZUNAGA UEDA ◽  
MITSUHARU AOKITSU
Keyword(s):  
Control System ◽  
Amplification Factor ◽  
Pressure Gauge ◽  
Pressure Control ◽  
Force Transducer ◽  
Hydraulic Pressure ◽  
Programmable Logic ◽  
Pressure Control System ◽  
Type Pressure ◽  
Measurement Repeatability

The 5 MN hydraulic amplification type force standard machine was renovated by replacing its hydraulic pressure control system, measuring ram and cylinder. For re-evaluation of uncertainty of force amplification factor, diameters of the main and mearsuring rams and cylinders were re-measured. A programmable logic controller with a personal computer is used to control the weight motion and the valve actuation, to monitor various kinds of sensors output, and to record readings of a force transducer under calibration. Fluctuation of calibration force was suppressed by using a quartz-resonance type pressure gauge, and measurement repeatability was improved to some extent. However, there remains room for improvement to further stabilize the calibration force by modifying the measuring ram.

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