Design and Simulation on Multi-Digit Numerical Control Valve in Water Hydraulics

2011 ◽  
Vol 422 ◽  
pp. 257-261
Author(s):  
Zeng Meng Zhang ◽  
Yong Jun Gong
Keyword(s):  
Control Valve ◽  
Poor Performance ◽  
Numerical Control ◽  
Hydraulic Control ◽  
Control Performance ◽  
Poppet Valve ◽  
Water Hydraulics ◽  
Water Hydraulic ◽  
The Stability ◽  
And Control

Due to the problems about Lubrication and sealing in water hydraulics, the poor performance, large leakage, extreme requirements of processing, high cost and poor anti-pollution properties exist in water hydraulic servo or proportional valves of spool structure and analogue control. A better seal is provided by the structure of the poppet valve comparing to the spool valve, however, poorer linearity and control accuracy accompanying inevitably. Aiming at improving the control performance of poppet valve, the design of the multi-digit numerical control valve is analyzed in this paper. The novel design using ball seat valves for digital bits is proposed to ensure enough seal ability and lower the cost. The simulation model of the multi-digit numerical control valve is built in AMESim software and the results show high linearity in flow control. However, large overshoot and oscillation encounter during the switching of the digits. Especially the switching process of the high digital bits requires to be regulated to reduce the large overshooting. The adjustment of the spring in the sensitive chamber of the bit valve can decrease the overshoot and improve the stability. These above contribute to the improvement of the control performance of water hydraulic control valves and applications of water hydraulics in the industry.

Modeling and Control of an Electro-Hydraulic Poppet Valve

2004 ◽  
Author(s):  
Patrick Opdenbosch ◽  
Nader Sadegh ◽  
Wayne J. Book
Keyword(s):  
Mathematical Model ◽  
Control Valve ◽  
Model Parameters ◽  
Hydraulic Control ◽  
Nonlinear Mathematical Model ◽  
Modeling And Control ◽  
Poppet Valve ◽  
Control Scheme ◽  
Experimental Approaches ◽  
And Control

This paper explores the dynamic modeling of a novel two stage bidirectional poppet valve and proposes a control scheme that uses a Nodal Link Perceptron Network (NLPN). The dynamic nonlinear mathematical model of this Electro-Hydraulic Control Valve (EHCV) is based on the analysis of the interactions among its mechanical, hydraulic, and electromagnetic subsystems. A discussion on experimental approaches to determine the model parameters is included along with model validation results. Finally, the control scheme is developed by proposing that the states of the EHCV follow a set of desired states, which are calculated based upon the desired valve flow conductance coefficient KV. A simulation is presented at the end to verify the proposed control scheme.

Research on the Stability of a System Consisting of a Water Hydraulic Control Valve and Cylinder

2016 ◽  
Author(s):  
Futoshi Yoshida ◽  
Shimpei Miyakawa ◽  
Shouichiro Iio
Keyword(s):  
Natural Frequencies ◽  
Tap Water ◽  
Control Valve ◽  
Working Fluid ◽  
Entire System ◽  
Hydraulic Control ◽  
Compensation Circuit ◽  
Design Guideline ◽  
Water Hydraulic ◽  
The Stability

Water hydraulic system using tap water as working fluid is a new driving method which provides high speed, high-output control, while providing safety, hygiene, and ecofriendliness. Its applicable markets widely range from food, health, pharmaceuticals, cosmetics, semiconductors, beverages, to energy industries. Applications of the water hydraulic technology differ from those of its oil counterpart in heavy industries. This paper is aimed at analytically considering the stability of systems that use tap water as the working fluid. We studied a comprehensive system, including a water hydraulic control valve, a cylinder, and piping for connecting these components, to determine the transfer function of the entire system that has three elements: a control valve; piping and cylinder; and a compensation circuit. Based on the determined function, we reviewed the relationship among natural frequencies of the system, including the control valve and piping, and examined the effect of the control valve and cylinder on the stability of the entire system according to the Hurwitz stability criterion. This gave us a design guideline about the compensation circuit that stabilizes the system by adjusting the natural frequency of the water hydraulic proportional control valve according to the natural frequencies of the piping and cylinder.

A Miniature On/Off Valve Concept for High Performance Water Hydraulics

2017 ◽  
Author(s):  
Miika Paloniitty ◽  
Matti Linjama
Keyword(s):  
High Performance ◽  
Control Valve ◽  
Hydraulic Control ◽  
Used Oil ◽  
Water Hydraulics ◽  
Starting Point ◽  
Pressure Medium ◽  
Water Hydraulic ◽  
Valve Control ◽  
Hydraulic Valve

Digital hydraulic control valve technology has shown its strengths in providing reliable, leak-tight and high performance valve control regardless of the pressure medium used, oil or water. This is enabled by the intelligent use of robust on/off seat valves. However, the availability of these valves for water hydraulics is limited, especially that of compact valves, which are needed for digital valve systems. Thus, with the aim to create a compact digital water hydraulic valve system, this paper presents the development process of a water hydraulic miniature valve. The starting point for the development is a previously developed miniature valve for oil hydraulics. Experimental results with the new prototype show that good performance can be achieved for the miniature valve even with using stainless steel materials. This enables high-performance digital water hydraulic control.

scholarly journals Modeling and stabilization of eccentric gravity machinery

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401775178
Author(s):  
Wu-Sung Yao
Keyword(s):  
Control System ◽  
Digital Signal Processor ◽  
Repetitive Control ◽  
Electric Energy ◽  
Digital Signal ◽  
Control Performance ◽  
Velocity Control ◽  
Stability Performance ◽  
The Stability ◽  
And Control

In general, eccentric gravity machinery is a rotation mechanism with eccentric pendulum mechanism, which can be used to convert continuously kinetic energy generated by gravity energy to electric energy. However, a stable rotated velocity of the eccentric gravity machinery is difficult to be achieved only using gravity energy. In this article, a stable velocity control system applied to eccentric gravity machinery is proposed. The dynamic characteristic of eccentric gravity machinery is analyzed and its mathematical model is established, which is used to design the controller. A stable running velocity of the eccentric gravity machinery can be operated by the controlled servomotor. Due to disturbances being periodic, repetitive controller is installed to velocity control loop. The stability performance and control performance of the repetitive control system are discussed. The iterative algorithm of the repetitive control is executed by a digital signal processor TI TMS320C32 floating-point processor. Simulated and experimental results are reported to verify the performance of the proposed eccentric gravity machinery control system.

Analysis and Simulation on Drive Characteristic of High-Strength Water Hydraulic Artificial Muscle

2014 ◽  
Vol 889-890 ◽  
pp. 488-492
Author(s):  
Zeng Meng Zhang ◽  
Jiao Yi Hou ◽  
Zheng Wen Sun ◽  
Yong Jun Gong ◽  
Jian Miao
Keyword(s):  
Flow Rate ◽  
Control Valve ◽  
Artificial Muscle ◽  
High Strength ◽  
Hydraulic Control ◽  
Hydraulic Circuit ◽  
Water Hydraulic ◽  
The Difference ◽  
Hydraulic Valves ◽  
Load Mass

Driving processes and characteristics are different between the water hydraulic artificial muscle and pneumatic artificial muscle due to the difference of work media employed in muscles. An appropriative hydraulic circuit was designed to control the pressure of the water hydraulic artificial muscle and the performance of this system was analyzed. An AMESim model of the control system was built and the dynamic characteristics are analyzed with various parameters of the hydraulic circuit and various loads by simulation. The results show that the performance of the water hydraulic control valve should agree with the dimension of the water hydraulic artificial muscle. The rated flow rate of the water hydraulic valves can be selected increasingly while the load mass is low. Meanwhile, the overshoot is generated and enlarged along with the increases of the flow rate and load mass. These contribute to the improvements of designs and researches on control systems of water hydraulic artificial muscles.

scholarly journals Performance Analysis on Depth and Straight Motion Control based on Control Surface Combinations for Supercavitating Underwater Vehicle

2021 ◽  
Vol 24 (4) ◽  
pp. 435-448
Author(s):  
Beomyeol Yu ◽  
Hyemin Mo ◽  
Seungkeun Kim ◽  
Jong-Hyon Hwang ◽  
Jeong-Hoon Park ◽  
...  
Keyword(s):  
Motion Control ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Underwater Vehicle ◽  
Control Surface ◽  
Control Performance ◽  
Friction Resistance ◽  
Control Loops ◽  
The Stability ◽  
And Control

This study describes the depth and straight motion control performance depending on control surface combinations of a supercavitating underwater vehicle. When an underwater vehicle experiences supercavitation, friction resistance can be minimized, thus achieving the effect of super-high-speed driving. Six degrees of freedom modeling of the underwater vehicle are performed and the guidance and control loops are designed with not only a cavitator and an elevator, but also a rudder and a differential elevator to improve the stability of the roll and yaw axis. The control performance based on the combination of control surfaces is analyzed by the root-mean-square error for keeping depth and straight motion.

Modeling Spool-Valve Flow Forces

2004 ◽  
Author(s):  
Noah D. Manring
Keyword(s):  
High Speed ◽  
Transient Flow ◽  
Control Valve ◽  
Hydraulic Control ◽  
Pressure Transient ◽  
Pressure Transients ◽  
Accepted Practice ◽  
The Stability ◽  
Spool Valve ◽  
Insight Into

This paper has been written to reconsider the important topic of transient flow forces that act on spool-type hydraulic control valves. Though this subject has been addressed and somewhat laid to rest many years ago, the high-speed applications of our present day require a fresh look at this topic for gaining deeper insight into the significant contributions that determine the stability and frequency response of the hydraulic control valve. Over thirty years ago, it became an accepted practice to neglect the pressure transient flow-forces acting on the spool valve as they were deemed to be minor compared to the velocity effects of the spool itself. In this paper, flow force models with and without the pressure transient term are compared and it is shown that the historic practice of neglecting pressure transients may no longer be valid. As a result, this paper provides justification for considering the pressure transients in the analysis and may provide an explanation for some of the discrepancies that have existed between theoretical expectations and laboratory results.

Properties of High Pressure Water Hydraulic Components with Modern Coatings

2013 ◽  
Vol 849 ◽  
pp. 100-107 ◽  
Author(s):  
Janusz Pobędza ◽  
Andrzej Sobczyk
Keyword(s):  
Environment Friendly ◽  
Water Hydraulics ◽  
Wide Range ◽  
Pressure Water ◽  
Hydraulic Cylinders ◽  
Water Hydraulic ◽  
Drive And Control ◽  
The Cost ◽  
Critical Regions ◽  
And Control

Water hydraulics is coming back as an alternative to oil and other not environment friendly working fluids used in a very wide range of fluid drive and control systems. The cost of water resistant materials for components is one of the barriers preventing the wide use of water hydraulics, especially moving parts such as pump pistons, surface of cylinder tubes and rods, poppet and seats, etc. to avoid corrosion. One of the common solutions is to use stainless steel there, where it can cooperate with other nonmetallic material such as plastic or other noncorrosive metallic composite to reduce friction. Thus some of research was directed to elaboration of special coating for covering surfaces in critical regions of water hydraulic components. The paper describes results of pilot research on selected components where such coating were introduced on regular carbon steel parts, same as used for oil hydraulics. First part of the article contents description of coating technology and some characteristics of coating layers. Second quotes selected results of conducted by authors research on coated hydraulic cylinders and poppet valves.

Design Analysis of Water Hydraulic Digital Valve

2011 ◽  
Vol 101-102 ◽  
pp. 148-153
Author(s):  
Zeng Meng Zhang ◽  
Yong Jun Gong
Keyword(s):  
High Speed ◽  
Pulse Width Modulation ◽  
Simulation Models ◽  
Hydraulic Control ◽  
High Frequency Response ◽  
Water Hydraulic ◽  
High Control ◽  
And Control ◽  
Control Accuracy ◽  
Poppet Valves

Lubrication and sealing are the key research points in water hydraulic technology. A better seal is provided by the structure form of the poppet valve comparing to the spool valve, however, poorer linearity and control accuracy accompanies inevitably. Aiming at improving the control performance of poppet valves, the design of the water hydraulic digital valve is analyzed in this paper. A high speed digital valve is designed and controlled by PWM (Pulse-Width Modulation) and actuated by a piezoelectric ceramic stack with high frequency response and control stiffness. Another new design using poppet valves for digital bits is proposed to ensure enough seal ability and lower the cost of the valve, namely the multi-digit on-off valve. The simulation models of these two types of valves are built and the results show the different performances between the valves. The high speed digital valve is provided with high control accuracy and responsiveness. In contrast, large overshoot and oscillation are encountered during switching on the digits of the multi-digit on-off valve. Especially the switching process of the high digital bits requires to be regulated to reduce the large overshoot. The above analysis contributes to the improvement of lubrication and sealing in water hydraulic control valves and applications of water hydraulics in the industry.

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