scholarly journals Impact of Hydraulic System Stiffness on Its Energy Losses and Its Efficiency in Positioning Mechanical Systems

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 294
Author(s):  
Piotr Dudziński ◽  
Aleksander Skurjat
Keyword(s):  
Hydraulic System ◽  
High Energy ◽  
Steering System ◽  
Torsional Stiffness ◽  
Design Stage ◽  
Energy Losses ◽  
Vehicle Class ◽  
Positioning Precision ◽  
Road Traffic Safety ◽  
Hydraulic Steering

Hydraulic steering systems for mechanical devices, for example, manipulators or vehicle steering systems, should be able to achieve high positioning precision with high energy efficiency. However, this condition is very often not met in practical applications. This is usually due to the stiffness of the hydraulic system being too low. As a result, additional corrections are required to achieve the required positioning precision. Unfortunately, this means additional energy losses in the hydraulic control system. In this study, this problem is presented using the example of a hydraulic steering system for an articulated frame steer vehicle. This hydraulic steering system should provide the required directional stability for road traffic safety reasons. So far, this issue, connected mainly with the harmful phenomenon of so-called vehicle snaking behaviour, has not been solved sufficiently practically. To meet the needs of industrial practice, taking into account the current global state of knowledge and technology, Wrocław University of Science and Technology is performing comprehensive experimental and computational studies on the snaking behaviour of an articulated frame steer wheeled commercial vehicle. The results of these tests and analyses showed that the main cause of problems that lead to the snaking behaviour of this vehicle class is the effective torsional stiffness of the hydraulic steering system. For this reason, a novel mathematical model of the effective torsional stiffness was developed and validated. This model comprehensively took into account all important mechanical and hydraulic factors that affect the stiffness of a hydraulic system, resulting in the examined snaking behaviour. Because of this, it is possible at the design stage to select the optimal parameters of the hydraulic steering system to minimise any adverse influence on the snaking behaviour of articulated frame steer wheeled vehicles. This leads to minimising the number of required corrections and minimising energy losses in this hydraulic steering system. The innovative model presented in the article can be used to optimise positioning accuracy, for example, in manipulators and any mechanical system with hydraulic steering of any system of any mechanical parts.

scholarly journals Design and simulation for driving system and steering system of hydraulic chassis of rice transplanter

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880890 ◽  
Author(s):  
Kai Hu ◽  
Wenyi Zhang
Keyword(s):  
Experimental Data ◽  
Hydraulic System ◽  
Slip Rate ◽  
Simulated Data ◽  
Steering System ◽  
Slide Valve ◽  
Design Requirement ◽  
Driving System ◽  
Hydraulic Steering ◽  
Hydraulic Motors

A new hydraulic chassis of rice transplanter is designed based on the paddy machinery operation requirements. Driving system adopts single pump four-motor scheme, and the anti-slide valve group is used to prevent the slippage of the shunt-wound hydraulic motors. Hydraulic steering system adopts single-way stable diverter valve for ensuring its response in time. Then, hydraulic system and components parameters are designed and calculated. The driving resistance and average slip rate are measured in paddy field. The experimental data verifies the correctness of theoretical calculation. The designed hydraulic driving system and steering system are simulated in AMESim. The simulated data, including pressure, flow, and torque, basically conform to the design requirement. The results verify the feasibility and reliability of chassis hydraulic scheme. The proposed design scheme may be extended to other vehicles for improving chassis performance.

Investigation of Thermal Effects in Direct Driven Hydraulic System for Off-Road Machinery

2016 ◽  
Author(s):  
Niko Karlén ◽  
Tatiana Minav ◽  
Matti Pietola
Keyword(s):  
Energy Efficiency ◽  
Hydraulic System ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Hydraulic Model ◽  
Energy Losses ◽  
Total Efficiency ◽  
Ambient Temperatures ◽  
Wheel Loaders ◽  
Save Energy

Several types of off-road machinery, such as industrial trucks, forklifts, excavators, mobile cranes, and wheel loaders, are set to be operated in environments which can differ considerably from each other. This sets certain limits for both the drive transmissions and working hydraulics of these machines. The ambient temperature must be taken into account when selecting the hydraulic fluid since the viscosity and density of the fluid are changing at different operating temperatures. In addition to the temperature, energy efficiency can also be a problem in off-road machinery. In most off-road machines, diesel engines are employed to produce mechanical energy. However, there are energy losses during the working process, which causes inefficiency in produced energy. For better energy efficiency, hybridization in off-road machinery is an effective method to decrease fuel consumption and increase energy savings. One of the possible methods to save energy with hybrids is energy regeneration. However, it means that the basic hydraulic system inside off-road machinery needs to be modified. One solution for this is to utilize zonal or decentralized approach by means of direct driven hydraulic (DDH) system. This paper aims to investigate a DDH system for off-road machinery by means of modelling and analyzing the effect of the temperature. In the direct-driven hydraulic system, the actuator is controlled directly by the hydraulic pump which is operated by the electric motor. Specifically, it is a valveless closed-loop hydraulic system. Thus, there will be no energy losses caused by the valves, and the total efficiency is assumed to be significantly higher. In order to examine the DDH system, a thermo-hydraulic model was created. Additionally, a thermal camera was utilized in order to illustrate the temperature changes in the components of the DDH system. To reproduce the action of the system in different circumstances DDH system was run at different ambient temperatures, and the component temperatures in the system were measured and saved for the analysis. The thermo hydraulic model was proven capable to follow the general trend of heating up.

scholarly journals NONLINEAR DYNAMICS OF SOFT FERMION EXCITATIONS IN HOT QCD PLASMA: SOFT-QUARK BREMSSTRAHLUNG AND ENERGY LOSSES

2010 ◽  
Vol 25 (04) ◽  
pp. 685-776 ◽  
Author(s):  
YU. A. MARKOV ◽  
M. A. MARKOVA ◽  
A. N. VALL
Keyword(s):  
Semiclassical Approximation ◽  
Gluon Plasma ◽  
High Energy ◽  
Energy Losses ◽  
Dynamical Equations ◽  
Model Case ◽  
Radiative Processes ◽  
Higher Order Terms ◽  
The Given ◽  
Approximate Expressions

Within the framework of a semiclassical approximation the general theory of calculation of effective currents and sources generating bremsstrahlung of an arbitrary number of soft quarks and soft gluons at collision of a high-energy color-charged particle with thermal partons in a hot quark–gluon plasma is developed. For the case of one- and two-scattering thermal partons with radiation of one or two soft excitations, the effective currents and sources are calculated in an explicit form. In the model case of "frozen" medium, approximate expressions for energy losses induced by the most simple processes of bremsstrahlung of soft quark and soft gluon are derived. On the basis of a conception of the mutual cancellation of singularities in the sum of so-called "diagonal" and "off-diagonal" contributions to the energy losses, an effective method of determining color factors in scattering probabilities containing the initial values of Grassmann color charges is suggested. The dynamical equations for Grassmann color charges of hard particle used by us earlier on are proved to be insufficient for investigation of the higher radiative processes. It is shown that for correct description of these processes the given equations should be supplemented successively with the higher-order terms in powers of the soft fermionic field.

scholarly journals Status of NICA

2018 ◽  
Vol 182 ◽  
pp. 02063 ◽  
Author(s):  
Vladimir Kekelidze ◽  
Alexander Kovalenko ◽  
Richard Lednicky ◽  
Victor Matveev ◽  
Igor Meshkov ◽  
...  
Keyword(s):  
High Energy Physics ◽  
Nuclear Research ◽  
High Energy ◽  
Design Stage ◽  
Target Area ◽  
Baryonic Matter ◽  
Accelerator Facility ◽  
Polarized Protons ◽  
The Status ◽  
Under Construction

The NICA (Nuclotron-based Ion Collider fAcility) is the new international research facility under construction at the Joint Institute for Nuclear Research (JINR) in Dubna. The main targets of the facility are the following: 1) study of hot and dense baryonic matter at the energy range of the maximum baryonic density; 2) investigation of nucleon spin structure and polarization phenomena; 3) development of JINR accelerator facility for high energy physics research based on the new collider of relativistic ions from protons to gold and polarized protons and deuterons as well with the maximum collision energy of sqrt(sNN) ~11GeV (Au79+ +Au79+) and ~ 27 GeV (p+p). Two collider detector setups MPD and SPD are foreseen. The setup BM@N (Baryonic Matter at Nuclotron) is commissioned for data taken at the existing Nuclotron beam fixed target area. The MPD construction is in progress whereas the SPD is still at the beginning design stage. An average luminosity of the collider is expected at the level of 1027 cm-2 s-1 for Au (79+) and 1032 cm-2 s-1 for polarized protons at 27 GeV. The status of NICA design and construction work is briefly described below.

Comparison of Numerical Methods for Determining Torsion Stiffness of Automotive Chassis

2011 ◽  
Author(s):  
Steven Tebby ◽  
Ebrahim Esmailzadeh ◽  
Ahmad Barari
Keyword(s):  
Finite Element Analysis ◽  
Analytical Approach ◽  
Torsional Stiffness ◽  
Design Stage ◽  
Element Analysis ◽  
Detailed Design ◽  
Vertical Displacements ◽  
Comparison Of The Results ◽  
Torsion Stiffness

The torsion stiffness of an automotive chassis can be determined using an analytical approach based purely on geometry, using an experimental method, or alternatively by employing a Finite Element Analysis (FEA) process. These three methods are suitable at different design stages and combined together could prove to be practical methods of determining the torsion stiffness of a chassis. This paper describes and compares two distinct FEA processes to determine the torsion stiffness of an automotive chassis during the detailed design stage. The first process iteratively applies forces to the model and records displacements, while the second process gradually applies vertical displacements in place of force to determine the torsional stiffness threshold. Each method is explained and supported with a case study to provide a basis of comparison of the results.

BINARY PULSAR SYSTEM PSR B1259-63/LS2883 AS A GAMMA-RAY EMITTER

2014 ◽  
Vol 28 ◽  
pp. 1460169 ◽  
Author(s):  
DMITRY KHANGULYAN ◽  
SERGEY V. BOGOVALOV ◽  
FELIX A. AHARONIAN
Keyword(s):  
Energy Band ◽  
Gamma Ray ◽  
High Energy ◽  
Energy Losses ◽  
Binary Pulsar ◽  
Emission Component ◽  
Emission Enhancement ◽  
Very High Energy ◽  
Hydrodynamical Simulations ◽  
Very High

Observations of the binary pulsar PSR B1259-63/LS2883 in the high energy and very high energy domains have revealed a few quite unusual features. One of the most puzzling phenomena is the bright GeV flare detected with Fermi/LAT in 2011 January, approximately one month after periastron passage. Since the maximum luminosity in the high energy band during the flare nearly achieved the level of the pulsar spin-down energy losses, it is likely that the particles, responsible for this emission component, had a strongly anisotropic distribution, which resulted in the emission enhancement. One of the most prolific scenarios for such an emission enhancement is the Doppler boosting, which is realized in sources with relativistic motions. Interestingly, a number of hydrodynamical simulations have predicted a formation of highly relativistic outflows in binary pulsar systems, therefore scenarios, involving relativistic boosting, are very natural for these systems. However a more detailed analysis of such a possibility, presented in this study, reveals certain limitations which put strict constraints on the maximum luminosity achievable in this scenario. These constraints render the "Doppler boosting" scenario to be less feasible, especially for the synchrotron models.

The Development of Marine Autopilot Simulator

2014 ◽  
Vol 602-605 ◽  
pp. 882-886
Author(s):  
Cai Qin Sun ◽  
Ling Jie Zhang ◽  
Jian Bo Sun
Keyword(s):  
Wind Wave ◽  
Steering System ◽  
Wave Flow ◽  
Turbine Engine ◽  
Operation Process ◽  
Ship Steering ◽  
Hydraulic Steering ◽  
Control Research ◽  
Ship Autopilot ◽  
The Mathematical Model

The mathematical model of the ship autopilot system is established which centering on marine hydraulic steering gear, based on the Nomoto ship motion model, and considered the influence of wind, wave, flow and other environmental factors on ship course angle. Depend on this model, the physical-digital hybrid simulation autopilot simulator is developed. This simulator has all of the operating functions of the ship steering system, it can not only simulate the turbine engine working scenarios, but also dynamically display the operation process, and the simulator is applicable to the ship track control research and crew training work.

scholarly journals Experimental Study on Antivibration Control of Electrical Power Steering Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhaojian Wang ◽  
Hamid Reza Karimi
Keyword(s):  
Control Strategy ◽  
Controller Design ◽  
Electrical Power ◽  
Steering System ◽  
Steering Wheel ◽  
Bench Test ◽  
Power Steering ◽  
Motor Controller ◽  
Hydraulic Steering ◽  
Wheel Vibration

We focus on the antivibration controller design problem for electrical power steering (EPS) systems. The EPS system has significant advantages over the traditional hydraulic steering system. However, the improper motor controller design would lead to the steering wheel vibration. Therefore, it is necessary to investigate the antivibration control strategy. For the implementation study, we also present the motor driver design and the software design which is used to monitor the sensors and the control signal. Based on the investigation on the regular assistant algorithm, we summarize the difficulties and problems encountered by the regular algorithm. After that, in order to improve the performance of antivibration and the human-like steering feeling, we propose a new assistant strategy for the EPS. The experiment results of the bench test illustrate the effectiveness and flexibility of the proposed control strategy. Compared with the regular controller, the proposed antivibration control reduces the vibration of the steering wheel a lot.

Sign in / Sign up

Export Citation Format

Share Document