scholarly journals MODELING A FLUID POWER DRIVE OF THE EXCAVATOR EQUIPMENT

2021 ◽  
Vol 1 (92) ◽  
pp. 178
Author(s):  
Alexander Yaryzhko
Keyword(s):  
Simulation Model ◽  
Mechanical System ◽  
Physical Simulation ◽  
Block Diagram ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Fluid Power ◽  
Computer Hardware ◽  
Transient Processes ◽  
Power Drive

Problem. The hydraulic drive of modern construction and road machines is quite complex, and it takes a lot of time and effort to model the entire drive in full. However, improving the quality of design with reducing terms and costs becomes possible only with the use of modern technologies, computer hardware and software. The existing models of hydraulic system working processes in the physical modeling environment SimHydraulics are presented by block diagram layouts from standard library elements (slide valve, hydraulic pump, hydraulic cylinder, safety and reverse valves, hydraulic locks, etc.). However, they do not consider the influence of time-varying external forces, which are a reaction during transient processes in multi-link mechanical systems. Goal. The aim of the work is to develop a simulation model of the fluid power drive of the excavator working equipment mechanical system in the MATLAB & SimHydraulics package for studying the dynamics of transient processes of multilink mechanical objects. Methodology. The article describes an example of developing a physical simulation model of the excavator working equipment fluid power drive in the SimHydraulics package. Using the real technical characteristics of the hydraulic equipment of the Borex 2201 excavator, the performance of the developed model was checked and the power characteristics of the actuators were determined. Originality. Using the blocks described in the article, a simulation model of the interaction of the excavator working equipment mechanical system with its fluid power drive can be created. Practical value. The model proposed makes it possible to obtain values characterizing transient processes, including changes in the value of the generalized coordinates of the characteristic points in the working equipment, the rate of their change, and the effort in the hydraulic cylinder. A visual representation of the manipulator movement can be obtained using the SimScape built-in visualization function. The resulting model allows solving problems of analysis and synthesis of excavator operation control systems.

Impact Assessment of Dynamic Characteristics on the Hydraulic Driven Machinery Operation

2018 ◽  
pp. 1-12
Author(s):  
A. D. Terenteva
Keyword(s):  
Dynamic Error ◽  
Total Error ◽  
Soil Layer ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Working Mechanism ◽  
Automated Control ◽  
Vertical Coordinate ◽  
Construction Machinery ◽  
The Difference

In civil engineering in Russia, trenching for utilities is currently under digging. To perform such works, it is necessary to use high-precision construction machinery, because inaccurate performance of works can lead to the break down of existing utilities, thereby affecting the residents of nearby houses and demanding the additional works for renewal.The most universal labour saver to perform construction works is hydraulic driven single-bucket excavators, which provide up to 38% of works. Therefore, to improve technical characteristics that affect the accuracy of the work performed is an important task.High requirements for the performance of works are defined by existing construction regulations: an allowable soil layer to remain is at most 0.05 m. To fulfil such requirements, an exact assessment of the working mechanism position and a trench profile is necessary.Examination of a manually operated digging process shows that an operator provides operations untimely, however an automated control system can solve this problem. Dynamic phenomena in the working mechanism have the greatest impact on the accuracy of the works performed.To assess the bucket digging edge position accuracy, a mathematical model of the working mechanism has been created. Based on the cycle scheme of the working process, the excessive displacements of the hydraulic cylinder rods under the load are taken into account. By the end of the cycle, the difference between the specified and obtained positions along the vertical coordinate has been 0.0892 m.A dynamic error of the hydraulic drive system of the working mechanism is considered as a sum of the error due to excessive displacements of the hydraulic cylinder rods and the error due to delay of the hydraulic drive, with the latter being calculated for the average time of delay taking into account the data available in the literature. The total error of the bucket digging edge position of the working mechanism is 0.1176 m, which is 2 times more than the value of 0.05 mConformity of all the links with specification requirements does not guarantee compliance with the required displacement accuracy of the bucket digging edge, and, thus, the soil layer to remain in the base of the trench can exceed the regulated value of 0.05 m.

A Mathematical Model Including Mechanical Structure, Hydraulic and Control of LHDS

Robotica ◽  
2021 ◽  
pp. 1-16
Author(s):  
Guoliang Ma ◽  
Kaixian Ba ◽  
Zhiwu Han ◽  
Zhengguo Jin ◽  
Bin Yu ◽  
...  
Keyword(s):  
Simulation Model ◽  
Hydraulic System ◽  
Inverse Dynamics ◽  
Hydraulic Drive ◽  
Operation Time ◽  
Variable Load ◽  
Mechanical Structure ◽  
Load Characteristics ◽  
Common Problems ◽  
And Control

SUMMARY In this paper, mathematical models of kinematics, statics and inverse dynamics are derived firstly according to the mechanical structure of leg hydraulic drive system (LHDS). Then, all the above models are integrated with MATLAB/Simulink to build the LHDS simulation model, the model not only considers influence of leg dynamic characteristics on hydraulic system but also takes into account nonlinearity, variable load characteristics and other common problems brought by hydraulic system, and solves compatibility and operation time which brought by using multiple software simultaneously. The experimental results show the simulation model built in this paper can accurately express characteristics of the system.

Development of hydraulic cylinder diagnostic methods by modeling methods

2021 ◽  
pp. 41-45
Author(s):  
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Technical Condition ◽  
Diagnostic Methods ◽  
Technical Diagnostics ◽  
Remaining Service Life ◽  
Construction Machine ◽  
Piston Speed ◽  
Variable Nature ◽  
Hydraulic Cylinders

The hydraulic drive of a construction machine is a complex dynamic system that is subjected to many dynamic loads of a variable nature and operates under conditions of variable external influences caused by various factors. During operation, these loads cause failure of the hydraulic transmission elements. To prevent these malfunctions, technical diagnostics should be applied by determining their current technical condition and remaining service life. The article assesses the working condition of hydraulic cylinders using a mathematical model. Using matlab/simulink software to simulate the hydraulic cylinder and hydraulic piston speed when changing the hydraulic cylinder clearance. The simulation results are presented. Keywords: diagnostic, hydraulic cylinder, simulation, development

Analysis of Flow Resistance Influence on Step-Down Process of the Control Rod Hydraulic Drive System

2021 ◽  
Author(s):  
Linqing Yang ◽  
Benke Qin ◽  
Hanliang Bo
Keyword(s):  
Theoretical Model ◽  
Flow Resistance ◽  
Inflection Point ◽  
Great Influence ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Drive System ◽  
Pressure Curve ◽  
Control Rod ◽  
Step Down

Abstract Control rod hydraulic drive system (CRHDS) is a new type of built-in control rod drive technology which is invented by INET, Tsinghua University. The integrated valve (IV) is the main flow control component of the CRHDS. Flow resistance of IV has a great influence on the control rod dynamic step-down process. The step-down performance experiments of CRHDS with different flow resistance of IV were conducted under room temperature conditions. Meanwhile, the theoretical model of hydraulic cylinder step-down process was established and combined with the relationship of the flow resistance of IV under the experimental conditions to get the dynamic response of the hydraulic cylinder. The calculation results of theoretical model agree well with the experimental data. On this basis, the theoretical model of hydraulic cylinder step-down process was applied to the high temperature working conditions with different flow resistance of IV. The analysis results show that at higher working temperature, with the increase of the flow resistance of IV control rod step-down average velocity decreases and step-down time increases correspondingly. There is an inflection point in the transient pressure curve and the pressure of the inflection point decreases gradually with the increase of the flow resistance. The pressure lag time after step-down also decreases. The research results lay the base for the design and optimization of the flow resistance of the IV for the CRHDS.

scholarly journals History, Structure And Types Of Microprocessors

2020 ◽  
Vol 02 (11) ◽  
pp. 39-46
Author(s):  
Hakimov Zohid Abdullayevich ◽  
Keyword(s):  
Block Diagram ◽  
Computer Hardware ◽  
Basic Concepts

This article gives you a brief overview on microprocessor types, performance, and computer hardware. The article also provides basic concepts about Microprocessors. Learn about microprocessor types, Intel, Intel Celeron, VIA, NVIDIA, Elbrus, Philips, Hitachi, Sun, AMD Athlon and more. You will learn about the functional parts of the microprocessor, the block diagram of the microprocessor, the command register of the microprocessor.

scholarly journals Modeling Study on Stiffness Characteristics of Hydraulic Cylinder under Multi-Factors

2017 ◽  
Vol 63 (7-8) ◽  
pp. 447 ◽  
Author(s):  
Hao Feng ◽  
Qungui Du ◽  
Yuxian Huang ◽  
Yongbin Chi
Keyword(s):  
Mechanical System ◽  
Volume Expansion ◽  
Hydraulic Cylinder ◽  
Experimental Results ◽  
Axial Deformation ◽  
Response Characteristics ◽  
Stiffness Model ◽  
Hydraulic Cylinders ◽  
Stiffness Characteristics ◽  
Cylinder Barrel

For a complex mechanical system driven by hydraulic cylinders, the dynamic response characteristics of the mechanical system are significantly affected by the stiffness characteristics of hydraulic cylinders. This paper comprehensively studies the impacts of various factors on the stiffness characteristics of the hydraulic cylinders, including the oil bulk modulus, the air content in the hydraulic oil, the axial deformation of the piston rod, the volume expansion of the cylinder barrel, the volume expansion of the metal pipes and the flexible hoses, and the deformation of the hydraulic cylinder sealing. By combining the theoretical analysis and the experimental results, the level of each impacting factor was quantified, and the stiffness model of the hydraulic cylinder was established. Finally, comparative analysis of the stiffness was conducted by taking the experimental hydraulic cylinder as an example; it was verified that the calculated results of the proposed hydraulic cylinder stiffness model approximated the experimental results. Compared with stiffness models presented in current literature, the average accuracy was improved by more than 15 %.

A DOE- and Kriging-Based Model for Studying on the Dynamics of Multibody Mechanical Systems With Revolute Joint Clearance

2013 ◽  
Author(s):  
Zhenhua Zhang ◽  
Liang Xu ◽  
Paulo Flores ◽  
Hamid M. Lankarani
Keyword(s):  
Simulation Model ◽  
Mechanical System ◽  
Contact Force ◽  
Design Parameter ◽  
Joint Clearance ◽  
Design Parameters ◽  
Force Model ◽  
Revolute Joint ◽  
Clearance Joint ◽  
Contact Force Model

Over the last two decades, extensive work has been conducted on dynamic effect of joint clearances in multibody mechanical systems. In contrast, little work has been devoted to optimizing the performance of these systems. In this study, analysis of revolute joint clearance is formulated in term of a Hertzian-based contact force model. For illustration, the classical slider-crank mechanism with a revolute clearance joint at the piston pin is presented, and a simulation model is developed using the analysis/design code MSC.ADAMS. The clearance is modeled as a pin-in-a-hole surface-to-surface dry contact, with appropriate contact force model between the joint and bearing surfaces. Different simulations are performed to demonstrate the influence of the joint clearance size and the input crank speed on the dynamic behavior of the system with the clearance joint. An innovative design-of-experiment (DOE)-based method for optimizing the performance of a mechanical system with the revolute joint clearance for different ranges of design parameters is then proposed. Based on the simulation model results from sample points, which are selected by a Latin hypercube sampling (LHS) method, a polynomial function Kriging meta-model is established instead of the actual simulation model. The reason for development and use of the meta-model is to bypass computationally intensive simulations of a computer model for different design parameter values in place of a more efficient and cost-effective mathematical model. Finally, numerical results obtained from two application examples, considering the different design parameters, including the joint clearance size, crank speed, and contact stiffness, are presented for further analyzing the dynamics of the revolute clearance joint in a mechanical system. This allows for predicting the influence of design parameter changes, in order to minimize contact forces, accelerations, and power requirements due to the existence of joint clearance.

scholarly journals Modelling and Simulation of Machine Tool Prototype with 6DOF Parallel Mechanism in Matlab / Simulink

2019 ◽  
Vol 254 ◽  
pp. 03002 ◽  
Author(s):  
Vladimír Bulej ◽  
Juraj Uríček ◽  
Manfred Eberth ◽  
Ivan Kuric ◽  
Ján Stanček
Keyword(s):  
Machine Tool ◽  
Simulation Model ◽  
Mechanical System ◽  
Parallel Mechanism ◽  
Control Algorithms ◽  
Kinematic Structure ◽  
Matlab Simulink ◽  
Parallel Kinematic ◽  
Functional Blocks ◽  
Functional Prototype

The article deals with the preparation of simulation model of mechanism with parallel kinematic structure called hexapod as an electro-mechanical system in software MATLAB/Simulink. The simulation model is composed from functional blocks represented each part of mechanism’s kinematic structure with certain properties. The results should be used for further simulation of its behaviour as well as for generating of control algorithms for real functional prototype.

Theoretical Analysis of Step-Down of Hydraulic Cylinder Motion for Control Rod Hydraulic Drive System Based on Model II

2017 ◽  
Author(s):  
Qianfeng Liu ◽  
Yuzheng Li ◽  
Benke Qin ◽  
Bo Hanliang
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Energy Technology ◽  
Hydraulic Control ◽  
Transient Pressure ◽  
Control Rod ◽  
Tsinghua University ◽  
Motion Time ◽  
New Energy ◽  
Step Down

Hydraulic Control Rod Drive Technology (HCRDT) is a newly invented patent and Institute of Nuclear and New Energy Technology Tsinghua University own HCRDT’s independent intellectual property rights. The hydraulic cylinder is the key part of this technology, so the performance of the hydraulic cylinder directly affects the HCRDT. Firstly, the theoretical model of the cylinder hydraulic has been obtained and verified by the experiment. Second, the step-down process of the cylinder hydraulic is analyzed. The results are shown that the model can analyze the performance of the cylinder, including the motion time of the cylinder, the transient pressure of the cylinder arrival, the transient impact energy of the cylinder arrival. At last, the cylinder and the drive mechanism can be optimized based on the result.

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