scholarly journals Eco Friendly Pipe Hose Cleaning System

2020 ◽  
Vol 9 (1) ◽  
pp. 934-942
Keyword(s):  
Hydraulic System ◽  
Harmful Effect ◽  
Reliable Data ◽  
Hydraulic Systems ◽  
Tolerance Level ◽  
Cleaning System ◽  
Particle Form ◽  
System Components ◽  
System 2 ◽  
Particulate Contaminants

It is inevitable that the oil in a hydraulic system will contain contamination in particle form. The sources and types of oil-borne contaminants are well known and will include particles of silica’s, metals flakes, elastomers and fibers of hydraulic hose material. Sizes and concentration of particulate contaminants are indicated. There is considerable interest among manufacturers and users of hydraulic systems in establishing acceptable limits of contaminations in which particular systems will operate satisfactorily. Such information would be used to 1) Specify the degree of filtration required in the system 2) Specify the contamination sensitivity of the system 3) Define the contamination tolerance level of the system To this end, it is necessary to gather reliable data on the performance of system components under controlled contaminated oil conditions. Thus, we designed a new Eco-friendly portable setup which does not use hazardous liquids to clean hose. Instead the setup uses a fresh, clean pressurized atmospheric air; hence there is no harmful effect on human health and contamination of environment.

Soft Switching Approach to Reducing Transition Losses in an On/Off Hydraulic Valve

2009 ◽  
Author(s):  
Michael B. Rannow ◽  
Perry Y. Li
Keyword(s):  
Hydraulic System ◽  
Check Valve ◽  
Fluid Flows ◽  
Soft Switching ◽  
Total System ◽  
System Efficiency ◽  
Hydraulic Systems ◽  
Controlled Systems ◽  
Flow Through ◽  
Hydraulic Valve

A method for significantly reducing the losses associated with an on/off controlled hydraulic system is proposed. There has been a growing interest in the use of on/off valves to control hydraulic systems as a means of improving system efficiency. While on/off valves are efficient when they are fully open or fully closed, a significant amount of energy can be lost in throttling as the valve transitions between the two states. A soft switching approach is proposed as a method of eliminating the majority of these transition losses. The operating principle of soft switching is that fluid can temporarily flow through a check valve or into a small chamber while valve orifices are partially closed. The fluid can then flow out of the chamber once the valve has fully transitioned. Thus, fluid flows through the valve only when it is in its most efficient fully open state. A model of the system is derived and simulated, with results indicating that the soft switching approach can reduce transition and compressibility losses by 79%, and total system losses by 66%. Design equations are also derived. The soft switching approach has the potential to improve the efficiency of on/off controlled systems and is particularly important as switching frequencies are increased. The soft switching approach will also facilitate the use of slower on/off valves for effective on/off control; in simulation, a valve with soft switching matched the efficiency an on/off valve that was 5 times faster.

Dynamic balance analysis of contamination control for hydraulic systems based on dynamic filtration ratio

2016 ◽  
Vol 68 (1) ◽  
pp. 45-51
Author(s):  
Guangying Ma ◽  
Shurong Ning ◽  
Yunlong Hu ◽  
jun Gao
Keyword(s):  
Hydraulic System ◽  
Dynamic Balance ◽  
Contamination Level ◽  
Hydraulic Systems ◽  
Level Control ◽  
Content Type ◽  
Contamination Control ◽  
Precise Control ◽  
Dynamic Filtration ◽  
The Relationship

Purpose – The aim of this study is to establish a dynamic model of the filtration ratio. For the problem that the measured value of the filtration ratio is far less than the theoretical value in the actual hydraulic filtering system, the paper aims to find the relationship between the filtration ratio and the parameters of the hydraulic systems, such as the contamination level and the dirt-holding quantity of the filter. Design/methodology/approach – The paper opted for the method of experimental analysis and simulation to determine the relationship between the filtration ratio and the parameters of the hydraulic system, and established a dynamic filtration ratio model. Findings – The paper provides a preliminary model of dynamic filtration ratio, and the model shows that the filtration ratio is exponentially related to the contamination level and the dirt-holding quantity. Different filters have different influence coefficients. The filtering capacity for a certain particle size and the contamination level control of the filter for different hydraulic systems can be judged according to the dynamic balance equation of hydraulic systems. Originality/value – The paper is useful in the selection of filters and in the precise control of the contamination level of the hydraulic system.

Calculation of a closed hydraulic volumetric system

2021 ◽  
pp. 27-30
Author(s):  
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Hydraulic System ◽  
Working Fluid ◽  
Wind Power Plant ◽  
Hydraulic Systems ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Oil Pump ◽  
Selection Of

An algorithm is proposed for calculating a closed volumetric hydraulic pump-hydraulic motor system using the example of the hydraulic system of a wind power plant, based on the calculation of the hydraulic systems of mobile machines. The main characteristics of the system components, the selection of initial data for the calculation, working fluid and diameters of hydraulic lines are analyzed. Keywords: hydraulic system, energy, fluid, oil, pump, motor, renewable energy source, wind power plant, machine. [email protected]

Synchronous Control Characteristics Analysis of Shield Propulsion Hydraulic System Based on Tracking Differentiator and Self-Adaptive Nonlinear PID

2021 ◽  
Author(s):  
Sen Li ◽  
XiaoHua Cao
Keyword(s):  
Pid Control ◽  
Hydraulic System ◽  
Control Method ◽  
Hydraulic Systems ◽  
Fuzzy Pid Control ◽  
Synchronous Control ◽  
Tracking Differentiator ◽  
Characteristics Analysis ◽  
Servo Tracking ◽  
Self Adaptive

Aiming at the low precision problem of multi-cylinder cooperative propulsion control in different regions of shield propulsion hydraulic systems under conditions of large load changes, this paper proposes a tracking differentiator and self-adaptive nonlinear PID (TD-NPID) control method to improve the synchronous control characteristics of shield propulsion hydraulic systems. First, the working principles of shield propulsion hydraulic systems were analyzed, and a mathematical model and TD-NPID controller were developed. Then, a simulation model was developed in AMESim-MATLAB environment, and the synchronous dynamic performances of fuzzy PID control, conventional PID control, and TD-NPID control were compared and analyzed. The results demonstrated that the shield propulsion hydraulic system with TD-NPID control had better servo tracking ability and steady-state performance than the systems with fuzzy or conventional PID control, which verified the feasibility of the application of TD-NPID control for the synchronous control of shield propulsion hydraulic systems.

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

2018 ◽  
Vol 8 (7) ◽  
pp. 1201 ◽  
Author(s):  
Haigang Ding ◽  
Jiyun Zhao ◽  
Gang Cheng ◽  
Steve Wright ◽  
Yufeng Yao
Keyword(s):  
Dynamic Response ◽  
Hydraulic System ◽  
Weight Ratio ◽  
Open Loop ◽  
Hydraulic Systems ◽  
Variable Speed ◽  
Weight Factors ◽  
Wide Range ◽  
Parallel Control ◽  
Valve Control

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.

scholarly journals Imitation models of aircraft hydraulic units with account for typical faults

2019 ◽  
Vol 18 (1) ◽  
pp. 30-41
Author(s):  
A. M. Gareyev ◽  
I. A. Popelnyuk ◽  
D. M. Stadnik
Keyword(s):  
Hydraulic System ◽  
Quantitative Estimation ◽  
Simulation Models ◽  
Statistical Information ◽  
Hydraulic Systems ◽  
Operational Parameters ◽  
Accurate Localization ◽  
Literary Sources ◽  
Reference Curves ◽  
The Impact

А method based on comparing oscilloscope patterns of operational parameters with reference curves is one of the most promising methods of diagnosing hydraulic systems among the existing ones. Its implementation does not allow accurate localization of the faulty unit in the system and quantitative estimation of the magnitude of the fault. To eliminate these shortcomings, it is advisable to use simulation models of hydraulic units, taking into account typical faults of a hydraulic system. Their use makes it possible to evaluate the effect of a particular malfunction on the change of dynamic parameters at the stage of mathematical modeling. As a result of the analysis of statistical information and literary sources, characteristic faults of hydraulic systems are identified. Their causes and the impact on the operation of hydraulic units are examined. Simulation models of units taking into account typical faults are described in the Matlab / Simscape software package. They are implemented using a typical hydraulic system as an example. Dynamic characteristics of a hydraulic system in a healthy condition and those of a system with one of the characteristic faults are compared.

Reinforcement Learning for Active Noise Control in a Hydraulic System

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Eric R. Anderson ◽  
Brian L. Steward
Keyword(s):  
Reinforcement Learning ◽  
Hydraulic System ◽  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Operating Point ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Active Noise ◽  
Pressure Ripple

Abstract Hydraulic pressure ripple in a pump, as a result of converting rotational power to fluid power, continues to be a problem faced when developing hydraulic systems due to the resulting noise generated. In this paper, we present simulation results from leveraging an actor-critic reinforcement learning method as the control method for active noise control in a hydraulic system. The results demonstrate greater than 96%, 81%, and 61% pressure ripple reduction for the first, second, and third harmonics, respectively, in a single operating point test, along with the advantage of feed forward like control for high bandwidth response during dynamic changes in the operating point. It also demonstrates the disadvantage of long convergence times while the controller is effectively learning the optimal control policy. Additionally, this work demonstrates the ancillary benefit of the elimination of the injection of white noise for the purpose of system identification in the current state of the art.

Dynamic surface control based on high-gain disturbance observer for electro-hydraulic systems with position/velocity constraints

2020 ◽  
pp. 095440622097826
Author(s):  
Yunfei Wang ◽  
Jiyun Zhao ◽  
Haigang Ding ◽  
He Zhang
Keyword(s):  
Hydraulic System ◽  
Disturbance Observer ◽  
High Gain ◽  
Dynamic Surface Control ◽  
Hydraulic Systems ◽  
Backstepping Method ◽  
Dynamic Surface ◽  
Surface Control ◽  
Velocity Constraints ◽  
Large Disturbance

The electro-hydraulic system is widely used in industrial production due to its high power-to-weight ratio, but the heavy-duty characteristics make the electro-hydraulic system subject to large disturbance force even if the actuator moves slightly, especially in mobile machines and multi-actuators system. Therefore, a position and velocity constraints method based on barrier Lyapunov function is proposed to guarantee the tracking error limited in a strict range to avoid the large disturbance force. Besides, the external disturbance, parameters uncertainty and modeling errors in the asymmetric cylinder electro-hydraulic systems affect the accuracy of position tracking seriously. So a high-gain disturbance observer is designed to estimate the lumped disturbance of the system, which can avoid amplification of the noise during the states measurement. In addition, dynamic surface control based on backstepping method is adopted to avoid the derivative explosion phenomenon when calculating the derivatives of virtual control inputs, which reduces the computational complexity of the system significantly. To verify the effectiveness of the proposed controller, proportional-integral controller and adaptive controller are designed to be compared with the high-gain disturbance observer–based dynamic surface controller with the backstepping method, and the comparison results show that the proposed controller has a more precise trajectory tracking performance.

New Hydraulic System Modelling

2004 ◽  
Vol 10 (10) ◽  
pp. 1493-1515 ◽  
Author(s):  
Friedrich Pfeiffer ◽  
Fredrik Borchsenius
Keyword(s):  
Hydraulic System ◽  
Computational Effort ◽  
System Modelling ◽  
Simulation Methods ◽  
Hydraulic Systems ◽  
Efficient Design ◽  
Fast Simulation ◽  
Stiff Differential Equations ◽  
Unilateral Constraints ◽  
Elastic Couplings

The efficient design of hydraulic systems requires fast simulation methods. In most simulation programs, the hydraulic components are coupled by compressible joints. Since the compressibility of oil is very small, this leads to stiff differential equations. To avoid these difficulties stiff elastic couplings can be replaced by algebraic and, in some cases, unilateral constraints. Examples for hydraulic components with unilateral behavior are check valves, cylinders with stop limits and fluid volumes, in which cavitation can occur. The resulting complementarity equations can be solved with a standard Lemke algorithm. Compared to conventional methods, this leads to a significant reduction of computational effort.

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