Research on back- pressure compensation characteristics of a pilot-assisted load control valve applied in overrunning load hydraulic systems

2021 ◽  
Vol 82 ◽  
pp. 102048
Author(s):  
Haibo Xie ◽  
Chengzhen Wang ◽  
Huayong Yang
Keyword(s):  
Control Valve ◽  
Back Pressure ◽  
Load Control ◽  
Hydraulic Systems ◽  
Pressure Compensation

Development of a New Generation of Independent Metering Valve Circuit for Hydraulic Boom Cylinder Control

2015 ◽  
Vol 9 (2) ◽  
pp. 143-152
Author(s):  
Mashruk Ahamad ◽  
◽  
Quang-Truong Dinh ◽  
Syed Abu Nahian ◽  
Kyoung-Kwan Ahn ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Control Valve ◽  
Hydraulic Systems ◽  
Large Power ◽  
Directional Control ◽  
Hydraulic Equipment ◽  
Pressure Compensation ◽  
Primary Focus ◽  
Spool Valves ◽  
New Generation

Recent research on hydraulic systems has mainly focused on energy saving. This is because the efficiency of hydraulic systems is very low even though they have large power-to-size ratios. In mobile hydraulic equipment, conventional hydraulic spool valves with pressure compensators have already been replaced by valve assemblies with four-valve independent metering with electronically controlled pressure compensation. The independent metering concept and microprocessor control have much more potential to save more energy than conventional proportional valve control because of the increased controllability of the system. The primary focus of this study is to reduce the number of Independent Metering Valves (IMV) by introducing one directional control valve. This new model offers two degrees of freedom, i.e., controlling velocity and pressure, just as in conventional IMVs. In the system described here, two of the three independent valves are active during metering. In this paper, the theory behind a new method of flow control based upon load feedback is presented for two of the five distinct metering modes, and its performance is investigated and compared to that of a conventional IMV configuration.

Design and Analysis of a Flow-Control Valve With Controllable Pressure Compensation Capability for Mobile Machinery

2021 ◽  
Author(s):  
Bo Wang ◽  
Yunwei Li ◽  
Long Quan ◽  
Lianpeng Xia
Keyword(s):  
Pressure Drop ◽  
Flow Control ◽  
Pressure Difference ◽  
Control Valve ◽  
Flow Control Valve ◽  
Continuous Control ◽  
Small Flow ◽  
Pressure Compensation ◽  
Force Compensation ◽  
Control Accuracy

Abstract There are the problems in the traditional pressure-compensation flow-control valve, such as low flow control accuracy, small flow control difficulty, and limited flow range. For this, a method of continuous control pressure drop Δprated (i.e. the pressure drop across the main throttling orifice) to control flow-control valve flow is proposed. The precise control of small flow is realized by reducing the pressure drop Δprated and the flow range is amplified by increasing pressure drop Δprated. At the same time, it can also compensate the flow force to improve the flow control accuracy by regulating the pressure drop Δprated. In the research, the flow-control valve with controllable pressure compensation capability (FVCP) was designed firstly and theoretically analyzed. Then the sub-model model of PPRV and the joint simulation model of the FVCP were established and verified through experiments. Finally, the continuous control characteristics of pressure drop Δprated, the flow characteristics, and flow force compensation were studied. The research results demonstrate that, compared with the traditional flow-control valve, the designed FVCP can adjust the compensation pressure difference in the range of 0∼3.4 MPa in real-time. And the flow rate can be altered within the range of 44%∼136% of the rated flow. By adjusting the compensation pressure difference to compensate the flow force, the flow control accuracy of the multi-way valve is improved, and the flow force compensation effect is obvious.

Electric Motors Coupled to Hydraulic Motors as Actuators for Hydraulic Hardware-in-the-Loop Simulation

2005 ◽  
Author(s):  
Scott Driscoll ◽  
James D. Huggins ◽  
Wayne J. Book
Keyword(s):  
Complete System ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Hardware In The Loop ◽  
Hydraulic Systems ◽  
Advantages And Disadvantages ◽  
Hydraulic Motors ◽  
Proportional Flow ◽  
Hil Simulation

Hardware-in-the-Loop (HIL) Simulation enables testing of an actual physical component of a system under a variety of conditions without the expense of full scale testing. In hydraulic systems, flows or pressures that interface with the component in question are controlled by a computer running a simulation designed to emulate a complete system under real operating conditions. Typically, servo valves are used as actuators to control the flows or pressures. This paper investigates the use of electric servo-motors coupled to hydraulic gear motors as alternative actuators, and discusses some of the advantages and disadvantages that motors have in comparison to valves. A demonstration HIL simulation involving a mobile proportional flow control valve attached to an emulated backhoe is described, and results are compared to data from a real backhoe.

Parametric study on interaction of blower and back pressure control valve for a 80-kW class PEM fuel cell vehicle

2016 ◽  
Vol 41 (39) ◽  
pp. 17595-17615 ◽  
Author(s):  
Dong Kyu Kim ◽  
Hyung Eun Min ◽  
Im Mo Kong ◽  
Min Kyu Lee ◽  
Chang Ha Lee ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Parametric Study ◽  
Control Valve ◽  
Pem Fuel Cell ◽  
Pressure Control ◽  
Back Pressure ◽  
Fuel Cell Vehicle ◽  
Pressure Control Valve

Design of Hydraulic System of Subsea X-Tree

2012 ◽  
Vol 155-156 ◽  
pp. 540-544
Author(s):  
Hong Lin Zhao ◽  
Jia Yu ◽  
Yuan Long Yue ◽  
Song Li ◽  
Bu Quan Guo
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Production Control ◽  
Control Valve ◽  
Control Model ◽  
Hydraulic Control ◽  
Hydraulic Systems ◽  
Hydraulic Power ◽  
Production Control System

Onshore hydraulic systems are not generally applied in subsea production control system,so how to design a special needed hydraulic system for subsea X-tree has been one of the hot research questions.Several specific hydraulic components were analyzed, such as hydraulic power unite,umbilical,subsea control model,hydraulic control valve and valve actuator, and then corresponding hydraulic schematic which can meet the requirements of subsea X-tree is presented.

CFD Analysis of Energy Loss of Direction Control Valve in Electro-Hydraulic Systems with Inverter

2014 ◽  
Vol 607 ◽  
pp. 393-396
Author(s):  
Aphaiwong Junchangpood
Keyword(s):  
Energy Loss ◽  
Transient Flow ◽  
Pressure Coefficient ◽  
Control Valve ◽  
Hydraulic Systems ◽  
Control Approach ◽  
Directional Control ◽  
Direction Control ◽  
Flow Pressure ◽  
Directional Control Valve

This paper presents a new approach for reducing energy consumption coupled with force and position controls in the electro-hydraulic systems (EHS). The EHS inverter will be added for control to vary the speed of electric motor driven hydraulic pump. In addition, a single directional control valve is used to control the system parameters, which cause loss of energy. The main objective of this research is to numerically analyze the energy loss in the new control approach in the EHS with the inverter by using a simple directional control valve. The spool displacements of 4/3 hydraulic closed center directional control valve, transient flow-pressure coefficient and energy loss were simulated with computational fluid dynamics (CFD). In addition, this paper presents CFD results. The relationships of flow rate variables with time-dependent pressure drop and energy loss were addressed. The flow behaviors related with transient flow-pressure coefficients were also discussed. It is found that the loss of energy increases, depending on both the large opening spool displacement and the inlet flow variable.

Exponential Tracking Control of a Hydraulic Proportional Directional Valve and Cylinder via Integrator Backstepping

2002 ◽  
Author(s):  
J. Chen ◽  
W. E. Dixon ◽  
J. R. Wagner ◽  
D. M. Dawson
Keyword(s):  
Pressure Drop ◽  
Tracking Control ◽  
Mechanical Load ◽  
Control Valve ◽  
Transient Behavior ◽  
Transportation Systems ◽  
System Response ◽  
Hydraulic Systems ◽  
Control Valves ◽  
Directional Control

Hydraulic systems are widely used in manufacturing processes and transportation systems where energy intensive operations are performed and “machine” control is vital. A variety of flow control products exist including manual directional control valves, proportional directional control valves, and servo-valves. The selection of a control valve actuation strategy is dependent on the system response requirements, permissible pressure drop, and hardware cost. Although high bandwidth servo-valves offer fast response times, the higher expense, susceptibility to debris, and pressure drop may be prohibitive. Thus, the question exists whether the economical proportional directional control valve’s performance can be sufficiently enhanced using nonlinear control strategies to begin approaching that of servo-valves. In this paper, exponential tracking control of a hydraulic cylinder and proportional directional control valve, with spool position feedback, is achieved for precise positioning of a mechanical load. An analytical and empirical mathematical model is developed which describes the transient behavior of the integrated components. A nonlinear backstepping control algorithm is designed to accommodate inherent system nonlinearities.

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