High-linear digital hydraulic valve control by an equal coded valve system and novel switching schemes

Paloniitty, Miika; Linjama, Matti

doi:10.1177/0959651817750519

Cited by 21 publications

(18 citation statements)

References 11 publications

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“…The length of the pipes was estimated using turbulent flow in pipe theory per Equation (1) and the properties of flow at the normal valve operating conditions. It was estimated that the pipe length should not be less than 0.13 m. 6 , Re ≤ 10 7 (1)…”

Section: Computational Domainmentioning

confidence: 99%

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Analysis of the Design of a Poppet Valve by Transitory Simulation

et al. 2019

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This article contains the results and analysis of the dynamic behavior of a poppet valve through CFD simulation. A computational model based on the finite volume method was developed to characterize the flow at the interior of the valve while it is moving. The model was validated using published data from the valve manufacturer. This data was in accordance with the experimental model. The model was used to predict the behavior of the device as it is operated at high frequencies. Non-dimensional parameters for generalizing and analyzing the effects of the properties of the fluid were used. It was found that it is possible to enhance the dynamic behavior of the valve by altering the viscosity of the working fluid. Finally, using the generated model, the influence of the angle of the poppet was analyzed. It was found that angle has a minimal effect on pressure. However, flow forces increase as angle decreases. Therefore, reducing poppet angle is undesirable because it increases power requirements for valve actuation.

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Section: Computational Domainmentioning

confidence: 99%

“…In recent years model based diagnostics and prevention has been investigated to improve the reliability of Electro-hydraulic, Electro-mechanical and Electro-pneumatic systems [2][3][4][5][6][7]. In typical EHSV's the radial clearance between the spool and the sleeve in the valves is in the order of 5 µm or 0.2 thousand of an inch [8].…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Design of a Poppet Valve by Transitory Simulation

et al. 2019

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“…where ω is the motor angular speed, C m is a motor leakage coefficient, D m is the motor displacement, and V 0 is the average volume of high-pressure chamber. In (6), "−" is used under LVPC model, and "+" is used under RVPC model.…”

Section: Hydraulic Motor Circuit the Continuity Equation Of The Wholmentioning

confidence: 99%

“…The traditional hydraulic control has two basic forms: valve control and pump control. The dynamic response of the valve control is fast, but the efficiency is low [5,6]; the efficiency of the pump control is high, but the dynamic response is slow [7][8][9]. Therefore, the independent pump control or valve control cannot solve the conflict between efficiency and response, and is not suitable to the complex speed regulation.…”

Section: Introductionmentioning

confidence: 99%

Valve‐Pump Parallel Variable Mode Control for Complex Speed Regulation Processes

et al. 2018

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To improve comprehensive performances of hydraulic systems with complex speed regulation processes, this paper proposes a new control scheme, valve-pump parallel variable mode control, which can change control modes according to control requirements and adjust the proportion of valve control and pump control in the speed regulation process. In this paper, we design a valve-pump parallel variable mode control system, explain its working principle, establish its mathematical model, analyse the influences of valve control on the system parameters, and at last, build an experimental system to carry out an experimental research. The experimental results show that during the speed regulation process, control modes could vary with control requirements, the switch between different control modes is smooth and meets expectations, and the proposed control approach can achieve excellent comprehensive performances for complex speed regulation, such as low-speed stability, fast response to load disturbance, and high efficiency. The valve-pump parallel variable mode control makes hydraulic control systems more flexible and suitable and enrich the current control schemes of hydraulic speed regulation systems.

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“…Traditional hydraulic control systems are of two basic types: pump control and valve control [1]. Valve control systems respond quickly to valve and load inputs but are less efficient due to throttling and overflow losses [2,3]. Pump control systems work efficiently since both system pressure and flow are closely matched with load requirements [4,5] but have a critical drawback: slow response.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Valve-Pump Weight Ratios on the Dynamic Response of Leaking Valve-Pump Parallel Control Hydraulic Systems

et al. 2018

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A new leaking valve-pump parallel control (LVPC) oil hydraulic system is proposed to improve the performance of dynamic response of present variable speed pump control (VSPC) system, which is an oil hydraulic control system with saving energy. In the LVPC, a control valve is operating at leaking status, together with a variable speed pump, to regulate the system flow of hydraulic oil simultaneously. Therefore, the degree of valve control and pump control can be adjusted by regulating the valve-pump weight ratio. The LVPC system design, mathematical model development, system parameter and control performance analysis are carried out systematically followed by an experimental for validation process. Results have shown that after introducing the valve control, the total leakage coefficient increases significantly over a wide range with the operating point and this further increases damping ratios and reduces the velocity stiffness. As the valve-pump weight ratio determines the flow distribution between the valve and the pump and the weight factors of the valve and/or the pump controls determines the response speed of the LVPC system, thus if the weight factors are constrained properly, the LVPC system will eventually have a large synthetic open-loop gain and it will respond faster than the VSPC system. The LVPC will enrich the control schemes of oil hydraulic system and has potential value in application requiring of fast response.

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High-linear digital hydraulic valve control by an equal coded valve system and novel switching schemes

Cited by 21 publications

References 11 publications

Analysis of the Design of a Poppet Valve by Transitory Simulation

Analysis of the Design of a Poppet Valve by Transitory Simulation

Valve‐Pump Parallel Variable Mode Control for Complex Speed Regulation Processes

The Influence of Valve-Pump Weight Ratios on the Dynamic Response of Leaking Valve-Pump Parallel Control Hydraulic Systems

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