scholarly journals ALGORITHM OF CONTROLLING AN ADAPTIVE HYDRAULIC CIRCUIT FOR MOBILE MACHINES

2021 ◽  
Vol 13 (3) ◽  
pp. 79-86
Author(s):  
Leonid Kozlov ◽  
◽  
Yurii Buriennikov ◽  
Oana Rusu ◽  
Volodymyr Pyliavets ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Hydraulic Systems ◽  
Hydraulic Circuit ◽  
Nonlinear Mathematical Model ◽  
Rosenbrock Method ◽  
Soil Hardness ◽  
Loose Soil ◽  
Feed Value ◽  
The Mathematical Model

Hydraulic systems based on adjustable pumps, proportional electrohydraulic equipment and controllers are used in mobile machines. The authors propose a new scheme of the hydraulic system for mobile machines, which provides the auger drilling operation. A number of studies have shown that a certain ratio should be maintained between the frequency of auger rotation and its feed during operation, where the productivity of soil disruption should not exceed the productivity of transporting loose soil from the drilling zone. Ensuring the required ratio between the speed of the auger rotation and its feed is implemented by a controller that works according to a certain algorithm. A nonlinear mathematical model of the hydraulic system was developed to create the algorithm for controller operation and setting. The equations of the mathematical model are solved in the MATLAB-Simulink environment by the Rosenbrock method. As a result of solving the equations for the mathematical model, the dependences of variables describing the state of the hydraulic system on time are obtained. The values of the controller settings are determined at which the hydraulic system works steadily, the error of flow rate stabilization, the time for pressure adjustment and readjustment does not exceed the allowable values. The algorithm for controlling the auger feed value is formed. This algorithm provides the necessary ratio between the auger feed and speed, as well as reducing the feed rate in the case of soil hardness increases. This creates the conditions for uninterrupted pit drilling at full depth and protection of the hydraulic system from overload.

Simulation Analysis of Rotary Steering Pump-Control Hydraulic System

2013 ◽  
Vol 295-298 ◽  
pp. 1995-2000
Author(s):  
Guang Fu Chen ◽  
Xiao Xian Yao ◽  
Si Bao Li
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Input Signal ◽  
Hydraulic System ◽  
Simulation Analysis ◽  
Harsh Environment ◽  
Hydraulic Systems ◽  
New Form ◽  
The Mathematical Model ◽  
Valve Control

The traditional valve control hydraulic systems have serious challenges in the harsh environment underground. The mathematical model of this new form of "motor - quantitative pump" controll system was established and simulated by using AMESIM software in this paper. According to the results of comparative analysis of the orifice parameters and the way to input signal, related parameters was determined, which can meet the characteristics of the system.

scholarly journals Transient Phenomena Generated in Emptying Operations in Large-Scale Hydraulic Pipelines

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2313
Author(s):  
Guillermo Romero ◽  
Vicente S. Fuertes-Miquel ◽  
Óscar E. Coronado-Hernández ◽  
Román Ponz-Carcelén ◽  
Francisco Biel-Sanchis
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Large Scale ◽  
Hydraulic Systems ◽  
Transient Phenomena ◽  
Pressure Drops ◽  
Pipeline Route ◽  
Air Pockets ◽  
Pressure Changes ◽  
The Mathematical Model

Air pockets generated during emptying operations in pressurized hydraulic systems cause significant pressure drops inside pipes. To avoid these sudden pressure changes, one of the most widely used methods involves the installation of air valves along the pipeline route. These elements allow air exchange between the exterior and the interior of the pipe, which alleviates the pressure drops produced and thus prevents possible breaks or failures in the structure of the installation. This study uses a mathematical model previously validated by the authors in smaller installations to simulate all hydraulic variables involved in emptying processes over time. The purpose of these simulations is the validation of the mathematical model in real large-scale installations, and to do this, the results obtained with the mathematical model are compared with actual measurements made by the partner company. The hydraulic system selected for the study is a pipeline with a nominal diameter of 400 mm and a total length of 1020 m. The results obtained from the mathematical model show great similarity with the experimental measurements, thus validating the model for emptying large pipes.

Modeling and Stability Analysis of Hydraulic System for Wave Simulation

2013 ◽  
Vol 291-294 ◽  
pp. 1934-1939
Author(s):  
Jian Jun Peng ◽  
Yan Jun Liu ◽  
Yu Li ◽  
Ji Bin Liu
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Mathematical Models ◽  
Hydraulic System ◽  
Simulation System ◽  
Displacement Sensor ◽  
Schematic Diagram ◽  
Wave Simulation ◽  
The Stability ◽  
The Mathematical Model

This thesis put forward a hydraulic wave simulation system based on valve-controlled cylinder hydraulic system, which simulated wave movement on the land. The mathematical model of valve-controlled symmetric cylinder was deduced and the mathematical models of servo valve, displacement sensor and servo amplifier were established according to the schematic diagram of the hydraulic system designed, on the basis of which the mathematical model of hydraulic wave simulation system was obtained. Then the stability of the system was analyzed. The results indicated that the system was reliable.

Hydropneumatic Suspension Design

2003 ◽  
Author(s):  
Mauri´cio Baldi ◽  
Pable Siqueira Meirelles
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Experimental Validation ◽  
Crop Protection ◽  
Load Factor ◽  
Height Control ◽  
Suspension Parameters ◽  
High Dynamic ◽  
The Mathematical Model ◽  
Dynamic Load Factor

This study proposes a robust and cheap hydropneumatic suspension system for agricultural trailers used to spread crop protection. This kind of vehicle has a high dynamic load factor that increases the axles loads when it is in use and require a height control to assure the same spraying efficiency keeping constant the distance between the spray nozzles and the crop. As the tractor has its own hydraulic system, the hydropneumatic suspension conception take in account that height control will be done by the hydraulic fluid, being the mass of gas kept constant. A mathematical model of the hydropneumatic spring stiffness behavior was developed, as well as a methodology to define the suspension parameters. Experimental validation of the mathematical model was carried out through the use of a real agricultural trailer, equipped with a hydropneumatic suspension projected using the procedure presented, and tested in a hydropuls® road simulator.

scholarly journals The study of dynamic processes in the hydraulic system of the roll clamp of a two-cone unwinder rolls pipe-welding unit 159-529

2020 ◽  
Vol 2 (127) ◽  
pp. 25-44
Author(s):  
Igor Mazur ◽  
Dmitry Sheludko ◽  
Mykhailo Petrov
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Hydraulic System ◽  
High Reliability ◽  
Operating Experience ◽  
Dynamic Loads ◽  
Hydraulic Systems ◽  
Software Environment ◽  
Return Stroke ◽  
Pipe Welding

The work is devoted to the study of dynamic loads arising in the hydraulic system of the clamping mechanism of a roll of a two-cone unwinder of rolls of tubes of a pipe-welding unit 159-529. The operating experience of the two-cone unwinder has shown that one of its drawbacks is the unsatisfactory operation of the roll clamp hydraulic system, in which increased dynamic loads are observed. In the hydraulic system of the roll clamping mechanism, the executive hydraulic cylinder is located at a large distance from the pressure source, therefore, it uses long hydraulic lines. In transient modes of operation of a machine with such a hydraulic system, wave processes arise in it (unsteady fluid motion), which affect the quality of its functioning.Based on the analysis of mathematical models used in the practice of dynamic calculations of real hydraulic systems, it is shown that it is advisable to use a system of partial differential equations converted by a finite-difference method into a system as a mathematical model that takes into account the design and operation of the hydraulic system of the roll clamp mechanism of a two-cone unwinder ordinary differential equations with boundary conditions. This makes it possible to create a dynamic model that allows with high reliability to analyze the behavior of the hydraulic system of the mechanism of the clamping roll of a two-cone unwinder. During the implementation of the proposed mathematical model in the Simulink MATLAB software environment, a study was made of the operating modes of the hydraulic system of the roll clamping mechanism. As a result of the study, it was shown that in the hydraulic system of the roll clamping mechanism of a two-cone unwinder, dynamic loads occur at the end of the return stroke, which significantly exceed the permissible values.In order to reduce dynamic loads, a valve operating procedure with a response time of 0.16 seconds is proposed. This allows you to significantly reduce dynamic loads in the hydraulic system of the roll clamping mechanism by reducing the speed of movement of the hydraulic cylinders at the end of the carriage return stroke.

scholarly journals Development and Evaluation of Energy-Saving Electro-Hydraulic Actuator

Actuators ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 302
Author(s):  
Triet Hung Ho ◽  
Thanh Danh Le
Keyword(s):  
Mathematical Model ◽  
Energy Consumption ◽  
Energy Saving ◽  
Energy Recovery ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
High Effectiveness ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Insight Into

This paper will develop a novel electro-hydraulic actuator with energy saving characteristics. This system is able to work in differential configurations through the shifting algorithm of the valves, meaning that this developed system can be adjusted flexibly to obtain the desirable working requirements including the high effectiveness of energy recovery from the load, high velocity or torque. Instead of establishing the mathematical model for the purpose of the dynamic analysis, a model of the developed actuator is built in AMESim software. The simulation results reveal that the system is able to save approximately 20% energy consumption compared with a traditional without energy recovery EHA. Furthermore, to evaluate the accuracy of the model, experiments will be performed that prove strongly that the experimental results are well matched to the results attained from the simulation model. This work also offers a useful insight into designing and analyzing hydraulic systems without experiments.

Evaluation of Oil Viscosity Influence on Hydraulic Shock in Long Pipe

2014 ◽  
Vol 630 ◽  
pp. 85-90 ◽  
Author(s):  
Adam Bureček ◽  
Lumír Hružík ◽  
Martin Vašina
Keyword(s):  
Mathematical Model ◽  
Mathematical Simulation ◽  
Experimental Measurement ◽  
Hydraulic System ◽  
Pipe Wall ◽  
Hydraulic Shock ◽  
Oil Viscosity ◽  
Oil Flow ◽  
End Pressures ◽  
The Mathematical Model

This article is aimed at mathematical simulation and experimental measurement of dynamics of liquid and pipe wall during hydraulic shock. Liquid compressibility and hydraulic line elasticity are taken into account in this case. The mathematical model is created using Matlab SimHydraulics software. The long pipe is simulated by means of segmented pipe. Experimental measurement is performed on a hydraulic system, which consists of flow-controlled aggregate, long pipe and seat valve. The hydraulic shock is caused by step closing of the seat valve that is located at the pipe end. Pressures at the end of the long pipe, oil flow and temperature are experimentally measured.

scholarly journals Study of Aircraft Wing Flap Hydraulic System Dynamics Under Damages Due to Operating an Aircraft

2008 ◽  
Vol 6 (3) ◽  
pp. 73-88
Author(s):  
Józef Błachnio ◽  
Andrzej Gronczewski
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Simulation Study ◽  
Hydraulic System ◽  
Hydraulic Systems ◽  
Aircraft Wing ◽  
Wear And Tear

Study of Aircraft Wing Flap Hydraulic System Dynamics Under Damages Due to Operating an Aircraft The paper indicates the main reasons for faulty operation of aeroplane wing flap hydraulic systems. A mathematical model of the wing flap dynamics has been presented, allowing an analysis of a simulation study taking into account damages due to usual wear and tear during operating of a plane.

Mathematic Model of Displacement Control Unit for Screw Distributor of Asphalt Paver

2013 ◽  
Vol 774-776 ◽  
pp. 295-298
Author(s):  
Zhi Nan Mi ◽  
Long An Chen ◽  
Jia Tao Tang
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Control Unit ◽  
Mathematic Model ◽  
Displacement Control ◽  
Rotating Speed ◽  
Dynamical Characteristics ◽  
Inertial Element ◽  
The Mathematical Model

Displacement control unit is an important part of hydraulic system for screw distributor. By adjusting the angle of swashplate, it can change the flow rate of pump and rotating speed of screw distributor. The rotating speed of screw distributor has influence on quality of road. The mathematical model of displacement control unit is presented. Its dynamical characteristics are analyzed. The mathematical model includes a reset spring gradient. The reset spring gradient is much smaller than the hydraulic spring rate, the effect of the reset spring gradient can be neglected. So an inertial element can be substituted by an integration element.

Hydraulic Control of Speed and Position of a Pneumatic Actuator

2015 ◽  
Vol 772 ◽  
pp. 334-338
Author(s):  
Mihai Avram ◽  
Constantin Bucşan ◽  
Despina Duminică ◽  
Dana Rizescu ◽  
Daniel Besnea
Keyword(s):  
Mathematical Model ◽  
Numerical Simulations ◽  
Hydraulic System ◽  
Experimental Results ◽  
Pneumatic Actuator ◽  
Hydraulic Control ◽  
Hydraulic Circuit

The paper presents an original pneumo-hydraulic system that controls the speed and the position of the actuated load by using a hydraulic circuit containing a hydraulic proportional throttle. A mathematical model of the solution is developed and numerical simulations are performed. The experimental results obtained on the built model confirm the theoretical ones.

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