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Viewing 1 to 30 of 216
2014-01-15
Journal Article
2013-01-9091
Dongfang Jiang
To get a sequence retainable rainflow cycle counting algorithm for fatigue analysis, an alternate equivalent explanation to rainflow cycle counting is introduced, based on which an iterative rainflow counting algorithm is proposed. The algorithm decomposes any given load-time history with more than one crest into three sub-histories by two troughs; each sub-history with more than one crest is iteratively decomposed into three shorter sub-histories, till each sub-history obtained contains only one single or no crest. Every sub-history that contains a single crest corresponds to a local closed (full) cycle. The mean load and alternate load component of the local cycle are calculated in parallel with the iterative procedure.
2004-03-08
Technical Paper
2004-01-1588
Adam B. Cooper, Michael Kokkolaras, Panos Y. Papalambros
Developing a new technology requires decision-makers to understand the technology's implications on an organization's objectives, which depend on user needs targeted by the technology. If these needs are common between two organizations, collaboration could result in more efficient technology development. For hybrid truck design, both commercial manufacturers and the military have similar performance needs. As the new technology penetrates the truck market, the commercial enterprise must quantify how the hybrid's superior fuel efficiency will impact consumer purchasing and, thus, future enterprise profits. The Army is also interested in hybrid technology as it continues its transformation to a more fuel-efficient force. Despite having different objectives, maximizing profit and battlefield performance, respectively, the commercial enterprise and Army can take advantage of their mutual needs.
2004-03-08
Technical Paper
2004-01-1222
Scott Kimbrough
Monte Carlo simulation is used to determine the likelihoods of competing scenarios offered by opposing parties involved in a motor vehicle accident. A case study is presented in which there is a dispute among the parties about who passed who first. It is shown that even though both scenarios are possible, one of the scenarios has a much greater likelihood. Besides demonstrating how Monte Carlo simulation provides probability information that can be used to weigh the likelihood of competing scenarios, the case study also provides another example of how Monte Carlo simulation can dig information out of the evidence surrounding an accident that cannot be obtained by other methods.
2004-03-08
Technical Paper
2004-01-1191
Marcus Hiemer, Sebastian Lehr, Uwe Kiencke, Takanori Matsunaga
The reproduction of the vehicle motion is a crucial element of accident reconstruction. Apart from the position of the center of gravity in an inertial coordinate system, the vehicle heading plays an important role. The heading is the sum of the yaw angle and the vehicle body side slip angle. In standard vehicles, the yaw angle can be determined using the yaw rate sensor and the wheel speeds. However, the yaw rate sensor is often subject to temperature drift. The wheel speed signals are forged at low speeds or due to slip. These errors result in significant deviations of reconstructed and real vehicle heading. Therefore, an intelligent combination of these signals is required. This paper describes a fuzzy system which is capable to increase the accuracy of yaw angle calculation by means of fuzzy logic. Before the data is applied to the fuzzy system, it is preprocessed to ensure the accuracy of the fuzzy system inputs.
2004-03-08
Technical Paper
2004-01-0923
E. G. Pariotis, D. T. Hountalas
This work is a part of an extended investigation conducted by the authors to validate and improve a newly developed quasi-dimensional combustion model. The model has been initially applied on an old technology, naturally aspirated HSDI Diesel engine and the results were satisfying as far as performance and pollutant emissions (Soot and NO) are concerned. But since obviously further and more extended validation is required, in the present study the model is applied on a new technology, heavy-duty turbocharged DI Diesel engine equipped with a high pressure PLN fuel injection system. The main feature of the model is that it describes the air-fuel mixing mechanism in a more fundamental way compared to existing multi-zone phenomenological combustion models, while being less time consuming and complicated compared to the more accurate CFD models. The finite volume method is used to solve the conservation equations of mass, energy and species concentration.
2004-03-08
Technical Paper
2004-01-1648
Xubin Song, Mehdi Ahmadian
This paper presents a parametric study of two semiactive adaptive control algorithms through simulation: the non-model based skyhook control, and the newly developed model-based nonlinear adaptive vibration control. This study includes discussion of suspension model setup, dynamic analysis approach, and controller tuning. The simulation setup is from a heavy-duty truck seat suspension with a magneto-rheological (MR) damper. The dynamic analysis is performed in the time domain using sine sweep excitations without the need to linearize such a nonlinear semiactive system that is studied here. Through simulation, the effectiveness of both control algorithms is demonstrated for vibration isolation. The computation flops of the simulation in the SIMULINK environment are compared, and the adaptability is studied with respect to plant variations and different excitation profiles, both of which come across typically for vehicle suspension systems.
2013-01-09
Technical Paper
2013-26-0150
Jeevan N. Patil, Sivakumar Palanivelu, Ajit Kumar Jindal
Air brake system is widely used in heavy duty trucks and buses due to its great performance and efficiency. Dual brake valve (DBV) is one the of major and crucial component of an air brake system as it is controlling the air flow from reservoir to brake chamber during braking operation. Currently, due to its own complexity, it is very difficult for designer to optimize different parameters. As experimentation is tedious and time consuming task, hence it is very important to have mathematical model of DBV during in early design stage. Differential equations have been formulated for individual component of DBV such as primary piston, primary valve, relay piston, and relay valve etc. system level mathematical model has been formulated and implemented in Matlab/Simulink to capture the dynamic pressure characteristic of DBV. At the same time mathematical model of DBV has been created in AMESim to check the validity of approach.
2005-04-11
Technical Paper
2005-01-0405
Namir J. Zara
The four wheel steer system better known as the Quadra Steer system (QS4) is a system that provides steering control of the rear wheel of long based pickups and large sport utilities. Analysis was utilized to develop Rear/Front (R/F) steering algorithm with the vehicle in it's normal mode which is characterized as vehicle at curb + 2 passengers or GVW/RGAWR on dry surface. Analysis utilized BZ3 control response simulation model to conduct this study. This dynamic model was used to evaluate key vehicle handling parameters to validate and optimize the algorithm.
2012-09-24
Technical Paper
2012-01-1897
Salem A. Haggag, Diaa Abidou
A vehicle braking system is used to provide acceptable drivability of the vehicle and ensure safety in different emergency situations that the vehicle may encounter. The braking system is used also as an integrated sub-system in many other important vehicle driving systems such as traction control, adaptive cruise control, accident avoidance and other vehicle systems in which the braking system plays an important role. This paper is dedicated to provide an accurate and at the same time simple enough hydro-mechanical braking system mathematical model that takes brake pad wear impact on the system pressure dynamics into consideration. A wear simulation procedure based on the concept of Archard's wear law is used and integrated in the nonlinear braking system model with flow compressibility taken into consideration. The presented model simulation results and the experimental tests results show good agreement and validate the confidence in the proposed model.
2016-09-27
Technical Paper
2016-01-8041
Richard A. Romano, George D. Park, Victor Paul, R. Wade Allen
Abstract Motion cueing algorithms can improve the perceived realism of a driving simulator, however, data on the effects on driver performance and simulator sickness remain scarce. Two novel motion cueing algorithms varying in concept and complexity were developed for a limited maneuvering workspace, hexapod/Stuart type motion platform. The RideCue algorithm uses a simple swing motion concept while OverTilt Track algorithm uses optimal pre-positioning to account for maneuver characteristics for coordinating tilt adjustments. An experiment was conducted on the US Army Tank Automotive Research, Development and Engineering Center (TARDEC) Ride Motion Simulator (RMS) platform comparing the two novel motion cueing algorithms to a pre-existing algorithm and a no-motion condition.
2016-09-27
Technical Paper
2016-01-8024
Saurabh Gupta, Gopichand Vunnava
Abstract In search of higher productivity, farmers are taking more than two crops in a year. In this farming pattern they don’t have much time for field preparation due to which rear mounted plough have become longer and heavier, necessitating the use of additional front-end weights and assister rams on the hydraulic lift. As plough length increases, the evenness of working depth over the full length of the implement deteriorates. To complete the farm work in one or two passes by utilizing maximum tractor power in order to save the fuel as well as time. The usage of front hitch and front PTO system on tractor forms a gateway for farmers to control the traffic on farm fields which is responsible for the soil compaction and emissions of greenhouse gases into the atmosphere by reducing the number of passes in agricultural field operations.
2015-01-14
Technical Paper
2015-26-0082
Jeevan N. Patil, Sivakumar Palanivelu, Vaibhav Aswar, Vipin Sharma
Abstract Pneumatic brake system is widely used in heavy truck, medium and heavy buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve (RV), Brake chambers. Dynamics of each valve is playing a crucial role in overall dynamic performance of the braking system. However, it is very difficult to find the contribution of each valve and pipe diameters in overall braking performance. Hence, it is very difficult to arrive a best combination for targeted braking performance as it is not possible to evaluate all combination on the actual vehicle. Hence, it is very important to have a mathematical model to optimize and evaluate the overall braking performance in early design phase. The present study is focusing on the mathematical model of a pneumatic brake circuit.
2013-05-13
Technical Paper
2013-01-1928
Ganesh Vijaykumar Kinagi, Suresh Wadkar, Dnyanesh Sonawane
Mathematical modeling of any system plays an important role in research and engineering applications. Development of hydropneumatic suspension system requires a complete understanding of physical phenomenon and generating governing equations of the same. In this paper, mathematical model of a typical hydropneumatic suspension system is made and simulation of such a complex multi domain system is programmed in MATLAB Simulink software. Vibration isolation potential of hydropneumatic suspension system is investigated through mathematical modeling, incorporating nonlinearity due to polytropic nature of gas spring.
2015-04-14
Technical Paper
2015-01-0608
Gang Tang, Hengjia Zhu, Yunqing Zhang, Ying Sun
Abstract The vehicle ride comfort behavior is closely associated with the vibration isolation system such as the primary suspension system, the engine mounting system, the cab suspension system and the seat suspension system. Air spring is widely used in the cab suspension system for its low vibration transmissibility, variable spring rate and inexpensive automatic leveling. The mathematical model of the air spring is presented. The amplitude and frequency dependency of the air spring's stiffness characteristic is highlighted. The air spring dynamic model is validated by comparing the results of the experiment and the simulation. The co-simulation method of ADAMS and AMESim is applied to integrate the air spring mathematical model into the cab multi-body dynamic model. The simulation and ride comfort test results under random excitation are compared.
2015-09-29
Technical Paper
2015-01-2763
S. F. Rahaman, Somenath Chatterjee
Abstract Steering pull during high speed braking of heavy commercial vehicles possesses a potential danger to the occupants. Even with negligible wheel-to-wheel brake torque variation, steering pull during the high speed braking has been observed. If the steering pull (i.e. steering rotation) is forcibly held at zero degree during high speed braking, the phenomena called axle twist, wheel turn and shock absorber deflection arise. In this work the data have been collected on the mentioned measures with an intention to develop a mathematical model which uses real time data, coming from feedback mechanism to predict the values of the measures in coming moments in order to aid steering system to ‘auto-correct’. Driven by the intention, ‘Time Series Analysis’, a well-known statistical methodology, has been explored to see how suitable it is in building the kind of model.
2016-09-27
Technical Paper
2016-01-8079
Zhiwei Zhang, Gangfeng Tan, Mengying Yang, Zhongjie Yang, Mengzuo Han
Abstract The hydraulic retarder is an important auxiliary braking device. With merits such as its high braking torque, smooth braking, low noise, long service life and small size, it is widely used on modern commercial vehicles. Transmission fluid of traditional hydraulic retarder is cooled by engine cooling system, which exhausts the heat directly and need additional energy consumption for the thermal management component. On account of the working characteristics of hydraulic retarder, this study designs a set of waste heat recovery system based on the Organic Rankine Cycle (ORC). Under the premise of ensuring stable performance of hydraulic retarder, waste heat energy in transmission fluid is recycled to supplement energy requirements for cooling system. First of all, a principle model, which is scaled down according to D300 retarder`s thermal power generation ration of 1:100, is established.
2016-09-27
Technical Paper
2016-01-8071
Igor Gritsuk, Vladimir Volkov, Yurii Gutarevych, Vasyl Mateichyk, Valeriy Verbovskiy
Abstract The article discusses the use of the combined heating system with phase-transitional thermal accumulator. The peculiarity of the presented system is that it uses thermal energy of exhaust gas, coolant and motor oil, and emissions of the internal combustion engine during its operation to accumulate the thermal energy. The results of experimental studies of the combined heating system are shown. A system and methods for pre-start and after-start heating of the vehicular engine in the investigated system are developed. The structure of the "combined heating” system to study the impact of its structural and adjustment parameters on the performance of thermal development of the vehicular engine is described. The use of the combined heating system within phase-transitional thermal accumulators is compared with the use of standard systems for a truck engine 8FS 9.2 / 8. It reduces the time of coolant and motor oil thermal development by 22.9-57.5% and 25-57% accordingly.
2013-11-27
Technical Paper
2013-01-2784
Saurabh gupta, Robesh Maity Sr, Shrirang Kulkarni cEng
The acute power shortage in rural India results in significant trade-offs on the living style of people residing there. As high as 10-15 hrs of load shedding, drives people to plan the work as per availability, limit the night time activities and depend on diesel generators for special events. The present work evaluates tractor, which has a high penetration in rural India (20 tractors per 1000 hectares) as a techno-commercially feasible alternative for rural electrification. The “Tractor-Electric Power” architecture has been redesigned, by adding inverter to the tractor battery and evaluating alternate architecture and applications. A mathematical model has been developed and simulations have been made by considering operating constraints, to evaluate the efficiency of this solution among various solutions.
2005-11-01
Technical Paper
2005-01-3527
Charles A. Radovich
A wind tunnel experiment has been conducted to determine the changes in drag and side force due to the presence and position of cab extenders on a model of a commercial tractor-trailer truck. The geometric variables investigated are the cab extenders angle of incidence, the tractor-trailer spacing and the yaw angle of the vehicle. Three cab extender angles were tested-0°, 15° (out) and -15° (in) with respect to the side of the tractor. The cab and trailer models have the same width and height. The minimum drag coefficient was found for the tractor and trailer combination when the cab extenders were set to 0° angle of incidence with respect to the headwind. This result holds for all yaw angles with moderate gap spacing between the tractor and trailer. This study suggests that commercial tractor-trailer trucks can benefit from adjustable cab extender settings; 0° when using a trailer and -15° when no trailer is used.
2005-11-01
Technical Paper
2005-01-3522
Kevin Hubert, Abhinav Kumar
All suspension systems have a common goal, which is to improve the ride in terms of comfort, handling, and safety. This is accomplished by influencing the motions afflicted by road irregularities to the wheels and axles while minimizing their affect on the vehicle body and frame. A successful design would therefore incorporate (1) a high Sprung-To-Unsprung-Mass-Ratio, (2) a Mass-Spring-Damper System between the vehicle body and the wheels, and (3) an anti-roll bar. Consequently, the wheels and axles endure the most of the motions caused by road irregularities while their affect is minimized on the vehicle body as desired. The objective of the Anti-Roll Stability Suspension Technology (ARSST) is to become an industry standard active suspension system for all vehicles while simultaneously offering cost-effective and performance-enhancing control to improve vehicle handling, safety, and comfort.
2005-11-01
Technical Paper
2005-01-3521
Sun Tao, Yu Fan
An investigation is made to the multiobjective suspension control problem for a heavy off-road vehicle based on mixed H2/H ∞ optimal control synthesis. A design procedure is explained based on a performance trade-off curve in order to solve this problem. In comparison with other control synthesis results we have obtained, it is shown that by combining both techniques into one mixed norm optimization framework, it is possible to exploit the strengths of each norm to provide better performance for the given hydropneumatic suspensions.
2005-11-01
Technical Paper
2005-01-3514
Frédéric Holzmann, Armin Sulzmann, Gernot Spiegelberg, Roland Siegwart, Heiner Bubb
This paper introduces a concept of predictive active safety by means of a full redundant architecture with the driver, from the perception of the environment to the vehicle controllers. The bottleneck of the current driver-vehicle association will be analyzed first. Then a virtual driver and the safety envelope of the different maneuvers will be described. A decision control will be presented that it matches the driver's command in this safety envelope. It is designed to give adequate feedback to the driver and can safely perform the command to the optimum of the chosen maneuver.
2005-11-01
Technical Paper
2005-01-3516
Jody D. Priddy, Randolph A. Jones
As a result of increased demand on the range of cargo types that U.S. military tactical trucks must transport, the effect of variations in the mass properties of the cargo on the roll stability of the trucks has become a serious issue. Vehicle dynamics experiments were conducted to obtain roll stability measurements for a tactical cargo truck hauling a broad range of rigid cargo loadings. A simple statics analysis for roll stability and the data obtained during the vehicle dynamics experiments were used to evaluate the relationship between the roll stability of the truck and the mass properties of the cargo. The results of the evaluation demonstrated that roll stability, quantified as the lateral acceleration at the wheel-liftoff threshold, can be accurately characterized as a function of: (1) the lateral center of gravity over the vertical center of gravity and (2) the longitudinal center of gravity over the wheelbase length.
2005-11-01
Technical Paper
2005-01-3499
S. M. Mehdi Ansarey M., M. Shariatpanahi, Shahram Salimi
The handling quality of a car is one of the most crucial parameters in the evaluation of the vehicle's overall performance. This quality is noticeably influenced by the structural and functional characteristics of the various components of the vehicle. The vehicle platform subsystems (i.e. steering, suspension, and braking) have major role in altering and tuning handling quality. It brings up special concerns in designing each of these mechanisms and need of having a comprehend understanding of their role in the handling characteristics of a vehicle. In this article, a general method for the optimization of steering system is presented. The investigation is focused on the geometrical parameters of a rack and pinion steering system, and their contribution on the handling characteristics. This kind of steering is common in medium class vehicles.
2005-11-01
Technical Paper
2005-01-3495
Dejun Zhuang, Fan Yu, Daofei Li
For the purposes of on-line control, e.g., in an automatic driving system, or of closed-loop directional control simulation, an optimal preview artificial neural network (ANN) driver model based on error elimination algorithm(EEA) is built. Then the optimal preview times are discussed in high frequency range in this system. The simulation results of optimal preview ANN driver model and Error Elimination Algorithm driver model are compared under the condition of different vehicle speeds and paths, which shows that the proposed approach is efficient and reliable enough, particularly for driver-vehicle closed-loop system.
2005-11-01
Technical Paper
2005-01-3639
Keith A. Tabor
A revolution in mobile hydraulic equipment is occurring. Conventional hydraulic spool valves with hydromechanical pressure compensators are being replaced by valve assemblies with four valve independent metering with electronically-controlled pressure compensation. In the system described here, two of the four independent valves are active during metering. This new topology offers significant advantages due to the two degrees of freedom provided. In this paper, the theory behind a new method of flow control based upon load feedback is presented for two of the five distinct metering modes. In addition, a new algorithm for setting the supply pressure is presented which is also based upon load feedback.
2005-11-01
Technical Paper
2005-01-3631
M. Borghi, M. Milani, F. Conrad
The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow-rate (and of the correspondent discharging orifice design) on the cushioning characteristics variation is firstly introduced. Then, with respect to the case of the cylindrical cushioning engagement, both the reliability and the limits of the numerical approach are highlighted through a numerical vs. experimental comparison, involving the piston velocity and the cylinder chambers pressure. After, with the aim of highlighting the effect of mechanical cushions design on a two effect linear actuator dynamic performances, the characteristics modulation of four alternative cushioning systems are determined and deeply analyzed.
2005-11-01
Technical Paper
2005-01-3632
Amir Shenouda, Wayne Book
The field of earth moving equipment is experiencing a transformation due to the introduction of more electronic control capability and advanced control concepts. Conventional hydraulic control systems are controlled by proportional directional spool valve. The construction of the spool valve is such that a given position of the spool determines the flow in and the flow out restriction sizes. Thus, metering in and metering out are dependent or coupled. A certain restriction size on the inlet corresponds to a certain restriction size on the outlet. Therefore, we have one degree of freedom. It can provide for good motion control but it cannot achieve energy saving potential at the same time. In this paper, the concept of ‘independent meter in / meter out’ will be emphasized. Decoupling of meter in from meter out provides for more controllability and potential for energy saving in overrunning load cases when compared with a conventional spool valve controlled hydraulic system.
2005-11-01
Technical Paper
2005-01-3634
M. Borghi, M. Milani, F. Paltrinieri, B. Zardin
In this paper some design aspects related to external gear pumps balancing surfaces are studied, and some useful guidelines for designing bearing blocks balancing surfaces are suggested. In order to study bearing blocks axial balance, a numerical procedure for the determination of the pressure distribution inside the clearance bounded by gears sides and bearing blocks internal surfaces is firstly presented and applied. After, the influence of bearing blocks geometry and pump operating conditions on the widening thrust is highlighted, considering both constant and variable lateral clearance heights. Then, the computations are performed to evaluate the widening thrust variation as a function of bearing blocks relative tilt with respect to gears lateral sides, and both positive and negative bearing blocks tilts are evidenced and discussed.
2005-11-01
Technical Paper
2005-01-3620
Keith A. Tabor
A revolution in mobile hydraulic equipment is occurring. Conventional hydraulic spool valves with hydromechanical pressure compensators are being replaced by valve assemblies with four valve independent metering with electronically-controlled pressure compensation. In the system described here, two of the four independent valves are active during metering. This new topology offers significant advantages due to the two degrees of freedom provided. One of these degrees of freedom used to control velocity is more fully described in a related paper. In this paper, it is shown how the second degree of freedom can be used to control pressure in an actuator workport or minimize velocity errors due to valve coefficient errors. Workport pressure control can be used to limit maximum or minimum workport pressures (e.g. prevent cavitation). Given certain criteria, an optimal solution can be obtained.
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