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.

Research on Disassembling Equipment for Construction Machinery Hydraulic Cylinder

2014 ◽  
Vol 989-994 ◽  
pp. 3323-3327
Author(s):  
Xing Hui Zhang ◽  
Jian Xin Zhang
Keyword(s):  
Hydraulic Cylinder ◽  
Residual Value ◽  
Working Mechanism ◽  
Hydraulic Power ◽  
Key Technology ◽  
Construction Machinery ◽  
Research Institute

Construction machinery hydraulic cylinder is usually discarded after service cycle. The residual value of discarded products can be recycled greatly by remanufacturing. Disassembly and assembly is the key process in hydraulic cylinder remanufacturing. The construction machinery hydraulic cylinder disassembly and assembly equipment is developed. Hydraulic power is adopted in this equipment. The clamping, positioning of cylinder tube is realized by hydraulic clamping mechanism automatically. The piston component pulling out or into cylinder tube is realized by hydraulic working mechanism automatically. This equipment has been applied successfully in the project of "key technology and equipment for construction machinery parts remanufacturing" in a research institute. The results indicate that the application of this equipment will not only increase the automaticity and efficiency remarkably, but also reduce the damage to hydraulic cylinder key part greatly.

SAFETY SUPPORT IN TRANSPORT CONSTRUCTION MACHINERY WITH HYDRAULIC DRIVE

2021 ◽  
Vol 2021 (7) ◽  
pp. 38-49
Author(s):  
Evgeniy Khristoforov ◽  
Nataliya Sakovich ◽  
Aleksandr Kuznecov
Keyword(s):  
Mathematical Modeling ◽  
Construction Industry ◽  
System Analysis ◽  
Time Moment ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Transport Processes ◽  
Construction Machinery ◽  
Motion Parameters ◽  
The Impact

Work purpose: the investigation of transport process safety in construction industry of the Bryansk region, the substantiation of reasons, factors and circumstances of accidents in the construction companies of the region, the substantiation of the impact of hydraulic drive unit failures upon safety of transport construction machinery with the hydraulic drive with the purpose of driver safety. Investigation problem: on the basis of the obtained results of the safety investigations of transport processes, reasons defined, revealed injury factors of drivers during the operation of the load flat car hydraulic drive of transport means to develop motion parameters of the “hydraulic drive-load flat car” system which will not allow arising oscillations of the system resulting in hydraulic drive failure arising which has influence upon driver’s work safety. The investigations were carried out on the basis of a system analysis of accident examinations in the regional construction industry which on the basis of statistical data allows the defining safety state of transport construction machinery. By means of investigations it is defined that 90% of transport construction machines are equipped with a hydraulic drive. In the hydraulic drive the most significant element is a hydraulic cylinder – the most loaded element performing all basic operations of a working process of loading and unloading. In the hydraulic drive there is used a telescopic hydraulic cylinder in which during operation there are revealed design-production defects (DPD) which result in injury of machine service personnel. One of DPD manifestations is oscillation formation in the hydraulic drive which results in the destruction of hydraulic cylinder attachment fitting. It is defined that the support of hydraulic drive reliability and safety is a difficult problem which needs a complex solution still at designing and creation, and during the operation. The complexity of the problem causes the necessity of design and operation parameter optimization, in the first place, that of an executing hydraulic cylinder of the hydraulic drive with the use of mathematical modeling. The review of the mathematical modeling methods of hydraulic cylinder parameters allows drawing the conclusion that the existing methods have many assumptions and do not allow creating completely reliable and safe transport construction engineering. The investigation novelty consists in the offered procedure for the solution of motion equations of the “hydraulic drive – load flat car” system which allows calculating the motion system parameters, defining the development of system oscillation above critical able to destruct a fitting unit of the hydraulic cylinder to the load flat car. Conclusion. The algorithm offered for the solution of mathematical equations allows making a conclusion on the stability and safety of the “hydraulic cylinder – load flat car” system, finding optimum values of motion parameters at any time moment of a transitional process.

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.

Dynamic Error Analysis of Measurement While Drilling Using Variable Geomagnetic In-Field Referencing

SPE Journal ◽  
2018 ◽  
Vol 23 (06) ◽  
pp. 2327-2338 ◽  
Author(s):  
Hojjat Kabirzadeh ◽  
Elena Rangelova ◽  
Gyoo Ho Lee ◽  
Jaehoon Jeong ◽  
Ik Woo ◽  
...  
Keyword(s):  
Reference Values ◽  
Dynamic Error ◽  
Directional Drilling ◽  
Average Reference ◽  
Marquardt Algorithm ◽  
Measurement While Drilling ◽  
The Difference ◽  
Dip Angle ◽  
Forward And Inverse Modeling

Summary The safe and economical determination of a wellbore trajectory in directional drilling is traditionally achieved by measurement-while-drilling (MWD) methods, which implement magnetic north-seeking sensor packages. Inaccuracies in the determination of well path arise because of random and systematic errors in the measurements of the sensors. Multistation analysis (MSA) and magnetic in-field referencing (IFR) have already demonstrated the potential to decrease the effects of errors because of magnetization of drillstring components along with variable errors caused by irregularities in the magnetization of crustal rocks in the vicinity of wells. Advanced MSA methodologies divide a borehole into several sections and use the average reference values of the total magnetic field, declination, and dip angle for analysis of errors in each section. Our investigations indicate that the variable-reference MSA (VR-MSA) can lead to a better determination of errors, specifically in areas of high magnetization. In this methodology, magnetic reference values are estimated at each station using forward and inverse modeling of surface-magnetic observations from IFR surveys. The fixed errors in magnetometer components are then calculated by minimizing the variance of the difference between the measured and unique estimated reference values at each station. A Levenberg-Marquardt algorithm (LMA) is adopted to solve the nonlinear optimization problem. Examination of this methodology using MWD data confirms more than 20% improvement in well-path-determination accuracy by comparing the results with the corrected path from the conventional MSA method and gyro surveys.

scholarly journals Microbial proportion and heterotroph CO2 flux from drainage peatland under oil palm plantation

2021 ◽  
Vol 9 (1) ◽  
pp. 3055-3061
Author(s):  
Eka Lupitasari ◽  
Rahayu Widyastuti ◽  
Heru Bagus Pulunggono
Keyword(s):  
Oil Palm ◽  
Water Movement ◽  
Soil Layer ◽  
Co2 Flux ◽  
Cellulolytic Bacteria ◽  
Microbial Decomposition ◽  
Oil Palm Plantation ◽  
Ligninolytic Fungi ◽  
The Difference ◽  
Total Bacteria

The difference in soil layer can affect heterotroph respiration that means CO2 fluxes from microbial decomposition in peatlands. Oil palm plants release root exudates transported to other places, i.e., shrub, by water movement, which can stimulate microbial activity. This study was conducted to learn the effects of differences of the soil layer and distance from the trunk in drainage peatland under oil palm plantation on total bacteria, fungi, cellulolytic bacteria, ligninolytic fungi, and heterotroph fluxes CO2, then compared to a shrub. Heterotroph respiration decreased with soil layer depth, where at the layer 0-20 cm released amount of CO2 as much 6.07 + 1.76, at 20-40 cm was 5.18 + 0.50, and at 40-60 cm 5.27 + 1.20 mg CO2 100 g-1 day-1, and tended higher than in shrub where a layer of 0-20 cm released 5.51 + 1.69, then decrease at 20-40 cm to 4.83 + 1.38, and at 40-60 cm 4.30 + 1.08 mg CO2 100 g-1 day-1. Total bacteria (107 CFU g-1) and fungi (105 CFU g-1) were higher than total cellulolytic bacteria (103 CFU g-1) and ligninolytic fungi (102 CFU g-1) in both under oil palm plantation and shrub. Organic acids affected the abundance of total bacteria and fungi but did not affect cellulolytic bacteria and ligninolytic fungi on both sites, as shown by a lower population and low cellulose and laccase enzymes. These findings showed that heterotroph CO2 flux tended higher in oil palm plantations and lignocellulolytic microbes are not the only source of heterotroph respiration.

scholarly journals Quantification of uncertainties in OCO-2 measurements of XCO<sub>2</sub>: simulations and linear error analysis

2016 ◽  
Vol 9 (10) ◽  
pp. 5227-5238 ◽  
Author(s):  
Brian Connor ◽  
Hartmut Bösch ◽  
James McDuffie ◽  
Tommy Taylor ◽  
Dejian Fu ◽  
...  
Keyword(s):  
Bias Correction ◽  
Total Error ◽  
Important Variable ◽  
Model Parameters ◽  
Error Sources ◽  
Variable Error ◽  
Operational Algorithm ◽  
The Difference ◽  
Variable Errors ◽  
Types Of Error

Abstract. We present an analysis of uncertainties in global measurements of the column averaged dry-air mole fraction of CO2 (XCO2) by the NASA Orbiting Carbon Observatory-2 (OCO-2). The analysis is based on our best estimates for uncertainties in the OCO-2 operational algorithm and its inputs, and uses simulated spectra calculated for the actual flight and sounding geometry, with measured atmospheric analyses. The simulations are calculated for land nadir and ocean glint observations. We include errors in measurement, smoothing, interference, and forward model parameters. All types of error are combined to estimate the uncertainty in XCO2 from single soundings, before any attempt at bias correction has been made. From these results we also estimate the "variable error" which differs between soundings, to infer the error in the difference of XCO2 between any two soundings. The most important error sources are aerosol interference, spectroscopy, and instrument calibration. Aerosol is the largest source of variable error. Spectroscopy and calibration, although they are themselves fixed error sources, also produce important variable errors in XCO2. Net variable errors are usually < 1 ppm over ocean and ∼ 0.5–2.0 ppm over land. The total error due to all sources is ∼ 1.5–3.5 ppm over land and ∼ 1.5–2.5 ppm over ocean.

General Situation of Constuction Machinery Development in Mechatronics Technology

2013 ◽  
Vol 357-360 ◽  
pp. 2909-2912
Author(s):  
Mi Tian ◽  
Xi Wei Zhang ◽  
Hai Ying Zu ◽  
Yi Na Qiao
Keyword(s):  
Remote Monitoring ◽  
Mechanical Engineering ◽  
Electronic Monitoring ◽  
Service System ◽  
General Situation ◽  
Automated Control ◽  
Construction Machinery ◽  
New Type ◽  
Vertical System

This is an introduction to brief development of construction equipments intellectualization and information with typical technology. Providing that the application of mechatronics which includes electronic monitoring, automatic alarm and fault self-diagnosis, a new type of transmission device, leveling system and vertical system, automated or semi-automated control, automated or semi-automated control and the construction machinery remote monitoring and service system in the field of mechanical engineering. This article describes the mechatronics trends in construction machinery.

scholarly journals Tensile response and fracturing process in moderate- and high-plasticity clays

2020 ◽  
pp. 1-11
Author(s):  
Giulia Forlati ◽  
Paul Shepley
Keyword(s):  
Moisture Content ◽  
Fracture Behaviour ◽  
Soil Layer ◽  
Clay Soils ◽  
Tensile Fracture ◽  
Future Research ◽  
High Plasticity ◽  
Bending Tests ◽  
Fracturing Process ◽  
The Difference

Sinkholes in clay soils can be considered as the collapse of a soil layer previously bridging a void. Here, flexural deformation in the clay drives the formation of tensile cracks from the lowest surface of the layer and the consequent soil collapse is from crack propagation. Considering a simplified model of the sinkhole geometry, this paper aims to describe the tensile and fracture behaviour of clay soils with different plasticity indices. Speswhite kaolin, London, and Durham clays were tested using direct tensile and bending tests. Moderate- and high-plasticity clays showed a nonlinear fracture response with increasing moisture content, while low-plasticity clays demonstrated a linear response. Bending tests confirmed the importance of the moisture content while the plasticity index confirmed the difference in ductile or fragile collapse for fracture propagation. To assess the results, elasto-plastic fracture mechanics (EPFM) theory was applied to clays with appropriate modifications. The analysis demonstrated that EPFM theory provides a good baseline for predicting tensile fracture behaviour in clay soils, which can be extended in future research.

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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