Modeling and Stability of a Hydraulic Load-Sensing Pump With Investigation of a Hard Nonlinearity in the Pump Displacement Control System

2014 ◽  
Author(s):  
Zachary D. Wagner ◽  
Roger Fales
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Flow Control ◽  
Control Valve ◽  
Pressure Control ◽  
Flow Control Valve ◽  
Pump System ◽  
Load Sensing ◽  
Pressure Control System ◽  
The Stability

Certain types of Load-sensing (LS) pumps utilize a hydro-mechanical control system designed to regulate the pressure difference, or margin pressure, between the inlet and outlet of a flow control valve. With a constant margin pressure, predictable flow control can be achieved by controlling the orifice area of the flow control valve. In this work, the stability of the pressure control system will be investigated. A combination of linear analysis and nonlinear analysis is employed to assess the stability of a particular LS pump system. Among many nonlinearities present in the hydro-mechanical system, of particular interest is the saturation inherent in the actuator that is used to displace the pump swash plate and the saturation within the 3-way spool valve that permits flow to reach the actuator. This saturation nonlinearity has been isolated from the rest of the system to enable stability analysis. Analysis of model characteristics is used to make conclusions about the stability of the system consisting of interconnected linear and nonlinear portions. The stability analysis is compared to results obtained through a simulation study using a nonlinear model based on first principles.

Dynamic modeling of a cabin pressure control system

2019 ◽  
Vol 234 (2) ◽  
pp. 401-415
Author(s):  
Kanhaiya Lal Chaurasiya ◽  
Bishakh Bhattacharya ◽  
AK Varma ◽  
Sarthak Rastogi
Keyword(s):  
Control System ◽  
Mathematical Models ◽  
Air Flow ◽  
Control Valve ◽  
Pressure Control ◽  
Absolute Pressure ◽  
Control Chamber ◽  
Matlab Program ◽  
Pressure Control System ◽  
Pressure Control Valve

Cabin pressure control system of an aircraft maintains cabin pressure in all flight modes as per the aircraft cabin pressurization characteristics by controlling the air flow from the cabin through the outflow valve of the cabin pressure control valve. The movement of outflow valve in turn depends on the air flow from the control chamber of cabin pressure control valve, which is controlled by the clapper and the poppet valves. These valves are actuated by absolute pressure and the differential pressure capsules, respectively depending upon the operating flight conditions. Mathematical models have been developed to simulate the air outflow rates from the cabin and the control chamber of cabin pressure control valve during steady-state and transient flight conditions. These mathematical models have then been translated into a MATLAB program to obtain plots of cabin pressures as a function of aircraft altitudes. The mathematical models are validated for standard cabin pressurization characteristics of a multirole light fighter/trainer aircraft. The model developed, thus can be used to produce a number of variants of cabin pressure control valve to suit different cabin pressurization characteristics.

Multidisciplinary Design Optimization of a High-Flow Control Valve

2013 ◽  
Vol 300-301 ◽  
pp. 1454-1457 ◽  
Author(s):  
Fang Cao ◽  
Yong Wang
Keyword(s):  
Flow Control ◽  
Design Optimization ◽  
Multidisciplinary Design Optimization ◽  
Control Valve ◽  
Pressure Control ◽  
High Flow ◽  
Field Analysis ◽  
Multidisciplinary Design ◽  
Practical Significance ◽  
Flow Control Valve

According to the real structure and work condition of a high-flow gas pressure control valve used in recycling generating electricity project, a multidisciplinary design optimization (MDO) model is set up. Taking the structure and flow field analysis results as designing criterion, the MDO framework is put forward, which realizing the integration of multidisciplinary and two physical fields of control valve. To ensure that the gas transmission capacity which is the design prerequisite, the optimization takes reducing noise of control valve as system goal, while the valve wall thickness and flow velocity are decreased. And the Reynolds number, stress intensity and body total weight are also meet requirements. From the standpoint of fluid and structure, to realize MDO is of great practical significance for advancing research level of high-flow control valves.

scholarly journals ANALYSIS OF A LOAD SENSING HYDRAULIC FLOW CONTROL VALVE

1996 ◽  
Vol 1996 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Rathindranath MAITI ◽  
Sandip PAN ◽  
Debasis BERA
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve ◽  
Hydraulic Flow ◽  
Load Sensing

Performance Improvement of Gas Liquid Cylindrical Cyclone Separators Using Integrated Level and Pressure Control Systems

2000 ◽  
Vol 122 (4) ◽  
pp. 185-192 ◽  
Author(s):  
Shoubo Wang ◽  
Ram S. Mohan ◽  
Ovadia Shoham ◽  
Jack D. Marrelli ◽  
Gene E. Kouba
Keyword(s):  
Control System ◽  
Integrated Control ◽  
Control Valve ◽  
Pressure Control ◽  
Rate Region ◽  
Cylindrical Cyclone ◽  
Pressure Control System ◽  
Carry Over ◽  
Operational Envelope ◽  
Integrated Control System

The performance of gas-liquid cylindrical cyclone (GLCC©) separators for two-phase flow metering loop can be improved by eliminating liquid overflow into the gas leg or gas blow-out through the liquid leg, utilizing suitable integrated control systems. In this study, a new integrated control system has been developed for the GLCC, in which the control is achieved by a liquid control valve in the liquid discharge line and a gas control valve in the gas discharge line. Simulation studies demonstrate that the integrated level and pressure control system is highly desirable for slugging conditions. This strategy will enable the GLCC to operate at constant pressure so as not to restrict well flow and simultaneously prevent liquid carry-over and gas carry-under. Detailed experimental studies have been conducted to evaluate the improvement in the GLCC operational envelope for liquid carry-over with the integrated level and pressure control system. The results demonstrate that the GLCC equipped with integrated control system is capable of controlling the liquid level and GLCC pressure for a wide range of flow conditions. The experimental results also show that the operational envelope for liquid carry-over is improved twofold at higher liquid flow rate region and higher gas flow rate region. GLCC performance is also evaluated by measuring the operational envelope for onset of gas carry-under. [S0195-0738(00)00804-9]

Design of Rotary-Type Flow Control Valve for Control of Water-Driven Spindle

2010 ◽  
Author(s):  
Yohichi Nakao ◽  
Hajime Niimiya ◽  
Takuya Obayashi
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Flow Control ◽  
Mathematical Models ◽  
Rotational Speed ◽  
Control Valve ◽  
Diamond Turning ◽  
Flow Control Valve ◽  
Type Flow ◽  
Rotary Type

Water-driven spindle was developed for producing small and precise parts by the diamond turning processes. Rotational speed of the spindle can be controlled by the flowrate supplied to the spindle. The paper describes a newly developed rotary-type flow control valve that is designed for controlling rotational speed of the water-driven spindle. In particular, the paper focuses on the establishment of the mathematical model capable of representing the characteristics of the open loop control system composed of the pump, flow control valve and spindle. Mathematical models are then derived so that a feedback control system can be designed using the models. Performances of the flow control valve and the spindle are examined through simulation as well as experiments. It is then verified that the derived mathematical models are capable of representing the performance of the system. In addition, the required positioning accuracy of valve rotation for achieving desired control of the rotational speed of the spindle is considered based on the derived linearized mathematical model.

scholarly journals Parameterized Uncertainty Model Using a Genetic Algorithm With Application to an Electro-Hydraulic Valve Control System

2015 ◽  
Author(s):  
Zuheng Kang ◽  
Bahaa I. Kazem ◽  
Roger C. Fales
Keyword(s):  
Genetic Algorithm ◽  
Control System ◽  
Flow Control ◽  
Robust Stability ◽  
Control Valve ◽  
Flow Control Valve ◽  
Uncertainty Model ◽  
Electrohydraulic Valve ◽  
Valve Control ◽  
Hydraulic Valve

This work proposes a new method of determining a parameterization of an uncertainty model using a genetic algorithm. A genetic algorithm is used in a unique way to solve the non-convex parameterization problem in this work. The methods presented here are demonstrated on an electrohydraulic valve control system problem. This demonstration includes parameterizing an uncertainty class determined from test data for 30 replications of an electrohydraulic flow control valve. The parameterization of the uncertainty is used to analyze the robust stability of a control system for a class of valves.

Corrugated Single Plane Pressure Control System Based on S7-300

2012 ◽  
Vol 201-202 ◽  
pp. 392-395
Author(s):  
Jian Mei Ye ◽  
Bin Liu
Keyword(s):  
Control System ◽  
Software Design ◽  
Production Management ◽  
Pressure Control ◽  
Central Control ◽  
Control Room ◽  
Single Plane ◽  
Pressure Control System ◽  
Hardware Configuration ◽  
The Stability

We proposed the structure and technics process in corrugated single plane pressure control system through the combination of weighing module SIWAREX and PLC S7-300. We also introduced the system work principle, the hardware configuration and PLC software design. As the special weighing module is applied here, the stability of the pressure load signal has been significantly improved to satisfy the pressure requirements of the board production process. The pressure can be set from the central control room in the production line or the workshop office through network to realize intelligentl control in production management so as to save the production data and avoid the paper break or bad conglutination problem. This design will have a very good application in the area of corrugated packaging in the future.

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