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Viewing 1 to 30 of 227
2013-11-27
Technical Paper
2013-01-2757
Sreegururaj Jayachander, Prasanna Vasudevan
Technology is one of the key determinants of the outcome in today's wars. Many targeting systems today use infra-red imaging as a means of acquiring targets when ambient light is insufficient for optical systems. Reducing thermal signatures offers an obvious tactical advantage in such a scenario. One way to reduce thermal emission of combat vehicles is to adopt highly efficient electrical power trains instead of internal combustion engines that tend to reject a sizeable amount of the input energy as heat. The tractor is one of the most versatile vehicles that are used in the theatre of combat for various operations such as haulage, clearing terrain, deploying bridges, digging trenches etc due to its excellent abilities in handling difficult terrain. A tractor powered by an all-electric power train was developed for civilian applications. The traction characteristics are identical to that of a conventional diesel powered tractor of comparable size.
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.
2005-04-11
Technical Paper
2005-01-0930
Bryon J. Sohns, Jeffrey L. Stein, Loucas S. Louca
Vital to the effectiveness of simulation-based design is having a model of known quality of the system being designed. The purpose of this paper is to validate a simplified dynamic model of an FMTV (Family of Medium Tactical Vehicles) for a range of system parameters using a previously developed technique for determining model robustness and accuracy within a design space. The literature provides an algorithm called AVASIM (Accuracy and Validity Algorithm for Simulation) for assessing model validity systematically and quantitatively. AVASIM assess the validity of a model based on a specific input and set of system parameters. The literature also defines a procedure for evaluating the robustness and accuracy of a model with respect to input and system parameter variations based on the AVASIM algorithm.
2012-09-24
Technical Paper
2012-01-1896
Ganesh Vijaykumar Kinagi, Sachin Pujari, Rajendra Birkhede, Dnyanesh Sonawane
Braking system is one of the most important system in the vehicle. In this paper, a general methodology for the design of braking system for a light military tracked vehicle is discussed in detail. It may be considered as a guide for predicting the values of various braking terms (such as brake force, brake torque, system pressure required, pedal force etc.) for the given inputs. The effects on these braking terms due to the variation of the inputs are also analyzed. A complete study of different types of brake actuation system has been done so that the appropriate one can be selected. A methology has been derived for braking system design for tracked vehicle and a program is written for the same.
2012-09-24
Technical Paper
2012-01-1911
Ganesh Vijaykumar Kinagi, Syam Prasad Pitchuka, Dnyanesh Sonawane
In this paper hydropneumatic suspension system design methodology for light military tracked vehicle is discussed in detail. A guide to locate the major impact factor & its effect on the system level design is demonstrated. Spring & damping characteristics of hydropneumatic suspension have significant bearing on the tracked vehicle mobility characteristics. A methodology has been derived to optimize the kinematics of the suspension system by optimizing the load transferring leverage ratio resulting in enhanced system life. The paper also discusses the analytical method used for prediction of spring & damping characteristics and the factors affecting them.
2015-01-14
Technical Paper
2015-26-0144
Pankaj Brijbihari Sharma, Prafulla Dahiwade
Abstract This paper discusses the off-road performance prediction of military application mini UGVs using terramechanics work deals with the development of performance simulation model for mini UGV in the Matlab/Simulink Software. Transient forward vehicle propulsion model and soil terrain interaction model have been built in the Simulink® software. It is a semi-empirical mobility model which predicts mini UGV performance on given terrain. The interaction between vehicle and the terrain causes resistances to vehicle propulsion. The model calculates these resistances, compares them to both the power limitations of the vehicle and the tractive limitations of the soil/terrain, to determine if the vehicle is immobilized. If not, then the vehicle speed is calculated based on available drawbar pull. The terrain is defined in terms of the soil parameters measured by the Bevameter. Semi-empirical equations suggested by Bekker have been used to model the soil terrain interaction.
2016-04-05
Journal Article
2016-01-0317
Yuanzhan Wang, Jason B. Siegel, Anna G. Stefanopoulou
Abstract This paper addresses scheduling of quantized power levels (including part load operation and startup/shutdown periods) for a propane powered solid oxide fuel cell (SOFC) hybridized with a lithium-ion battery for a tracked mobile robot. The military requires silent operation and long duration missions, which cannot be met by batteries alone due to low energy density or with combustion engines due to noise. To meet this need we consider an SOFC operated at a few discrete power levels where maximum system efficiency can be achieved. The fuel efficiency decreases during transients and resulting thermal gradients lead to stress and degradation of the stack; therefore switching power levels should be minimized. Excess generated energy is used to charge the battery, but when it’s fully charged the SOFC should be turned off to conserve fuel.
2016-04-05
Journal Article
2016-01-0313
Andrej Ivanco, Kan Zhou, Heath Hofmann, Zoran S. Filipi
Abstract Design of military vehicle needs to meet often conflicting requirements such as high mobility, excellent fuel efficiency and survivability, with acceptable cost. In order to reduce the development cost, time and associated risk, as many of the design questions as possible need to be addressed with advanced simulation tools. This paper describes a methodology to design a fuel efficient powerpack unit for a series hybrid electric military vehicle, with emphasis on the e-machine design. The proposed methodology builds on previously published Finite element based analysis to capture basic design features of the generator with three variables, and couples it with a model reduction technique to rapidly re-design the generator with desired fidelity. The generator is mated to an off the shelf engine to form a powerpack, which is subsequently evaluated over a representative military drive cycles.
2016-04-05
Technical Paper
2016-01-0314
Larry Michaels, Curtis G. Adams, Michael Juskiewicz
Abstract A simulation approach is defined that integrates a military mission assessment tool (One Semi-Automated Forces) with a commercial automotive control/energy consumption development tool (Autonomie). The objective is to enable vehicle energy utilization and fuel consumption impact assessments relative to US Army mission effectiveness and commercial drive cycles. The approach to this integration will be described, along with its potential to meet its objectives.
2016-04-05
Journal Article
2016-01-0316
Dorin Drignei, Zissimos Mourelatos, Ervisa Kosova, Jingwen Hu, Matthew Reed, Jonathan Rupp, Rebekah Gruber, Risa Scherer
Abstract We have recently obtained experimental data and used them to develop computational models to quantify occupant impact responses and injury risks for military vehicles during frontal crashes. The number of experimental tests and model runs are however, relatively small due to their high cost. While this is true across the auto industry, it is particularly critical for the Army and other government agencies operating under tight budget constraints. In this study we investigate through statistical simulations how the injury risk varies if a large number of experimental tests were conducted. We show that the injury risk distribution is skewed to the right implying that, although most physical tests result in a small injury risk, there are occasional physical tests for which the injury risk is extremely large. We compute the probabilities of such events and use them to identify optimum design conditions to minimize such probabilities.
2016-04-05
Journal Article
2016-01-0310
Xinran Tao, John R. Wagner
Abstract The pursuit of greater fuel economy in internal combustion engines requires the optimization of all subsystems including thermal management. The reduction of cooling power required by the electromechanical coolant pump, radiator fan(s), and thermal valve demands real time control strategies. To maintain the engine temperature within prescribed limits for different operating conditions, the continual estimation of the heat removal needs and the synergistic operation of the cooling system components must be accomplished. The reductions in thermal management power consumption can be achieved by avoiding unnecessary overcooling efforts which are often accommodated by extreme thermostat valve positions. In this paper, an optimal nonlinear controller for a military M-ATV engine cooling system will be presented. The prescribed engine coolant temperature will be tracked while minimizing the pump, fan(s), and valve power usage.
2016-04-05
Technical Paper
2016-01-0312
Robert S. Jane, Gordon G. Parker, Wayne Weaver, Denise M. Rizzo
Abstract Vehicles with power exporting capability are microgrids since they possess electrical power generation, onboard loads, energy storage, and the ability to interconnect. The unique load and silent watch requirements of some military vehicles make them particularly well-suited to augment stationary power grids to increase power resiliency and capability. Connecting multiple vehicles in a peer-to-peer arrangement or to a stationary grid requires scalable power management strategies to accommodate the possibly large numbers of assets. This paper describes a military ground vehicle power management scheme for vehicle-to-grid applications. The particular focus is overall fuel consumption reduction of the mixed asset inventory of military vehicles with diesel generators typically used in small unit outposts.
2016-04-05
Technical Paper
2016-01-0308
Tomasz A. Haupt, Angela E. Card, Matthew Doude, Michael S. Mazzola, Scott Shurin, Alan Hufnagel
Abstract The Powertrain Analysis and Computational Environment (PACE) is a forward-looking powertrain simulation tool that is ready for a High-Performance Computing (HPC) environment. The code, written in C++, is one actor in a comprehensive ground vehicle co-simulation architecture being developed by the CREATE-GV program. PACE provides an advanced behavioral modeling capability for the powertrain subsystem of a conventional or hybrid-electric vehicle that exploits the idea of reusable vehicle modeling that underpins the Autonomie modeling environment developed by the Argonne National Laboratory. PACE permits the user to define a powertrain in Autonomie, which requires a single desktop license for MATLAB/Simulink, and port it to a cluster computer where PACE runs with an open-source BSD-3 license so that it can be distributed to as many nodes as needed.
2015-01-14
Technical Paper
2015-26-0181
Mukund Trikande, Sujithkumar Muralidharan, Vinit Jagirdar
Abstract This study is made on a simplified pitch model of an armored fighting vehicle. Jerks and angular acceleration inside the vehicle compartment Affects accurate firing attack and reduced fatigue to the occupants in Vehicle. The Stability Augmentation Technique can enhance the stability and ride comfort of the vehicle platform from road and firing disturbance. The force requirement for stabilizing the platform is calculated from the displacement of vehicle body in terms of pitch angle and Heave displacement with respect to the equilibrium position, the equivalent force at suspension mounting points required to stabilize the platform is calculated using a force transformation technique. The required force is given by an active Damper for stabilization, within the limit of damper capacity.
2016-04-05
Journal Article
2016-01-1404
Steven E. Hodges
Abstract Fire protection, active and passive, has been, and is, an important area of concern during the design, development and deployment phases for all modern ground vehicles. All US military vehicles carry handheld fire extinguishers, and many tactical and all combat vehicles have automatic fire protection systems that protect the crew, engine, and in some cases, external components such as fuel tanks and wheels, from potentially catastrophic combat events involving fire. Vehicle designs also mitigate fire hazards by separating the vehicle occupants from the most flammable materials, e.g., fuel and ammunition, as much as practical. Explosion protection of the crew and passengers in military vehicles is a unique application with unique requirements that must balance suppression actions with safety limits.
2017-03-28
Technical Paper
2017-01-0261
Randolph Jones, Robert Marinier III, Frank Koss, Robert Bechtel, John A. Sauter
Abstract When evaluating new vehicle designs, modeling and simulation offer techniques to predict parameters such as maximum speed, fuel efficiency, turning radius, and the like. However, the measure of greatest interest is the likelihood of mission success. One approach to assessing the likelihood of mission success in simulation is to build behavior models, operating at the human decision-making level, that can execute realistic missions in simulation. This approach makes it possible to not only measure changes in mission success rates, but also to analyze the causes of mission failures. Layering behavior modeling and simulation on underlying models of equipment and components enables measurement of more conventional parameters such as time, fuel efficiency under realistic conditions, distance traveled, equipment used, and survivability.
2014-09-30
Technical Paper
2014-01-2282
Dhiraj Dashrat Salvi
Braking system is having a key importance in vehicle safety & handling stability. In this research paper I had developed a circuit model of Antilock braking system where the operating medium is hydro-pneumatic. A solenoid operated modulator valve consisting of two 2/2 valves is connected in line with the air cylinder & hydraulic master cylinder assembly. Using methodology of response time calibration time taken to modulate hydraulic pressure against pneumatic pressure is evaluated. The signal input to the modulator valve is given by the Electronic controlled unit (ECU). All results obtained is exported to an excel file using Data Acquisition software with pressure myograph system. It gives easy and intuitive readings based on the signal program from ECU for various inputs (i.e. ramp, step). The signals are program for various inputs in order to check the fidelity of the circuit. These readings are easily customized to get the optimum graphs.
1958-01-01
Technical Paper
580308
A. J. RUTHERFORD, J. W. HOESCHEN, S. F. WILLIAMS
1958-01-01
Technical Paper
580305
T. G. TIMBERLAKE, R. G. ALEXANDER, N. P. OGLESBY, W. H. LEATHERS
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.
2007-10-30
Technical Paper
2007-01-4189
H Rabibunnisa, Swarna Ramesh
The Suspension systems of Armoured Fighting Vehicles demand non-linear spring characteristics, variable damping, good ride cum handling characteristics and excellent crew comfort. Mechanical System Laboratory of CVRDE has carried out extensive performance evaluation and endurance testing activity of the Hydro gas Suspension Systems in the existing test rig. The tests involve measurement of spring characteristics and damping behavior. The stringent design requirement of futuristic combat vehicles has called for severe test conditions, accurate simulation of terrain and extensive fatigue testing for design validation. Hence MSL has taken up the design of state of the art Suspension Test Facility to meet the test protocol. This facility is capable of conventional testing of components using constant frequency - constant amplitude, simulation of service loads, acceptance testing, durability and endurance testing with fixed end configuration.
2007-10-30
Technical Paper
2007-01-4190
V. L. Parnell, S. Boedo, M. H. Kempski, K. B. Kochersberger, M. H. Haselkorn
This paper illustrates the potential benefits of identifying planet gear bushing failures in military Light Armored Vehicles (LAVs) using vibration signature analysis techniques over conventional thermocouple methods. A pneumatically driven test rig was developed to measure the vibrational response of a lubricated dimpled bushing using accelerometers mounted externally to the bushing housing. Fourier-based signature analysis techniques are employed to track the wear history of the bushing liner material under steady load and steady shaft rotational speed. Vibration data collected from the accelerometers was analyzed by calculating the band power of specific frequency bands. Three separate run-to-failure tests showed a direct linear relationship between band power and bushing wear for frequency bands that may be related to the worn dimpled pattern of the bushing. The data was also shown to be a reasonable predictor of bushing wear within specified confidence bounds.
2007-10-30
Technical Paper
2007-01-4192
Przemyslaw Siminski, Maciej Zajac
The paper includes theoretical basis of the terrain-tire interaction model and results of simulation research of driving force dependent on tire types, their characteristics and ground characteristic as well. Mathematical model of military truck has been built using MBS software DADS. The model has been validated on deformable ground using tires with well known characteristics. In conclusions authors described obtained results and possibilities of applying of developed model for analyzing military trucks dynamics and mobility on different kind of terrain with different kind of tires.
2008-10-07
Technical Paper
2008-01-2656
Shuo Xu*, Fan Yu
A semi-track air-cushion vehicle (STACV) which combines an air-cushion lifting system with a semi-track propulsion system is an efficient solution for heavy-duty vehicles working on soft terrain, such as the vehicles for agricultural, oil industrial and military purposes. Focusing on optimizing fuel economy of the vehicle, five main issues are studied in this paper. Firstly, based on the analyses of resistances for the STACV in a sandy loam working condition, a theoretical model for fuel consumption of 100km, which is an evaluation index for fuel economy, is established. Secondly, through simplified by a group of constraint equations based on the physical structure of the vehicle, the running parameters and control target (fuel consumption of 100km) could be expressed by the following two measurable and adjustable parameters, fan rotational speed and vehicle forward speed.
2006-10-31
Technical Paper
2006-01-3587
Leo P. Miller, Carlos E. Agudelo
Military and commercial fleets share many challenges, most of which are driven by Federal laws, regulations, and policies. The US military has one of the largest and most varied wheeled vehicle fleets in the world with a broad range of vehicle weights and types, most over 10,000 lbs GVW. These vehicle brake systems include disc and drum, using mechanical, hydraulic, and air actuation systems. The US military buys vehicle systems only, not the individual components or subsystems other than for spare parts (a.k.a. Secondary Items). In addition, brake shoes are bought as assembled units only and not as separate brake blocks or lining. The objective of the Government project presented in this paper was to provide a decision-making tool so that the responsible engineering authority could make a reasoned decision on the acceptability of alternative spare parts and sources through a Government-approved standardized off-vehicle testing process.
2006-10-31
Technical Paper
2006-01-3569
Joshua B. Stewart, E. Harry Law
Current military operations in Iraq and Afghanistan are unique because the battlefield can be described as a non-linear, asymmetrical environment. Units operate in zones that are susceptible to enemy contact from any direction at any time. The response to these issues has been the addition of add-on armor to HMMWV's and other tactical vehicles. The retro-fitting of armor to these vehicles has resulted in many accidents due to rollover and instability. The goal of this paper is to determine possible causes of the instability and rollover of up-armored tactical vehicles and to develop simulation tools that can analyze the steady-state and transient dynamics of the vehicles. Models and simulations include a steady-state rollover scenario, analysis of understeer gradient, and a transient handling analysis that uses models of both a human driver and a vehicle to analyze vehicle response to an obstacle avoidance maneuver.
2006-10-31
Technical Paper
2006-01-3541
Carl P. Evans, Robert J. Watts
Abstract In September 2005 the United States Army's Tank-Automotive Research, Development, and Engineering Center (TARDEC) instituted a ground mobility, robotics systems integration and evaluation laboratory: the TARDEC Robotics Skunk Works. The goal of this laboratory is to integrate and assess new and developing unmanned systems technologies to support efficient transitioning of the technologies to ATO and PM/PEO programs. The first unmanned system to enter the TARDEC Robotics Skunk Works will be the Tactical Amphibious Ground Support System - Common eXperimental (TAGS-CX). Key development design requirements for this modified COTS platform, which weighs less than 2 tons, include modularity and interoperability of ground robot systems and mission payloads.
2005-11-01
Technical Paper
2005-01-3560
Nicholas Dembski, Giorgio Rizzoni, Ahmed Soliman
A methodology has been developed to generate military vehicle driving cycles for use in vehicle simulation models. This methodology is based upon the mission profile for a vehicle, which is typically given within a vehicle's specifications and lists the types of terrains that the vehicle is likely to encounter. A simplistic vehicle powertrain and road load model and the Bekker vehicle-soil interaction model are used to estimate the vehicle performance over each type of terrain. Two types of driving cycles are generated within a Graphical User Interface developed within MATLAB using the results of the vehicle models: Linear modes driving cycles, and Real-world driving cycles.
2005-11-01
Technical Paper
2005-01-3556
Paul W. Richmond, Burhman Q. Gates, Erwin A. Baylot
Ground vehicle mobility models in U.S. Army entity-level force-on-force simulations have largely been tailored to the specific application (e.g., Janus, Close Combat Tactical Trainer [CCTT], Modular Semi-Automated Forces [MODSAF], OneSAF Testbed Baseline [OTB]). The NATO Reference Mobility Model (NRMM) is the Army standard model for single ground vehicle performance. However, it is much too complex and is not designed for use in entity-level simulations. Janus uses lookup tables based on NRMM speeds, and CCTT uses forces derived from algorithms internal to NRMM. The U.S. Army is developing two new entity-level simulations: CombatXXI and the One Semi-Automated Forces Objective System (OOS), which both have requirements to use NRMM as the basis for their ground vehicle mobility calculations. The U.S. Army Engineer Research and Development Center teamed with the U.S.
2005-05-10
Technical Paper
2005-01-2068
Robert W. Page, Wsewolod “Jeep” Hnatczuk, Jeffrey Kozierowski
A Stewart & Stevenson M1084A1 FMTV 5-ton cargo truck was used as the subject of a study to evaluate advanced powertrain thermal management components and subsystems. Funded by the U.S. Army TACOM and the National Automotive Center (NAC) under a Small Business Innovative Research grant (SBIR Phase II), the project focused on improving thermal management of the vehicle while reducing the peak fuel consumption by >10% in a vehicle having limited ram air cooling. The FMTV was used as a surrogate test bed to investigate thermal management technologies that could be applied to vehicles with confined package space, such as light armored vehicles. The vehicle was equipped with a thermal management system featuring distributed system architecture, electric coolant pumps and fans, electronic control valve, multiple air-cooled heat exchangers, and an electronic control system with PID feedback. The entire thermal management system was mounted in a metal enclosure behind the truck cab.
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