Using Modeling and Simulation to Evaluate Traction of Track Vehicles

2000 ◽  
Author(s):  
David D. Gunter ◽  
Michael D. Letherwood
Keyword(s):  
Dynamic Performance ◽  
Vehicle Design ◽  
Ground Vehicles ◽  
Ground Vehicle ◽  
Us Army ◽  
3 Dimensional ◽  
Tractive Effort ◽  
The Us ◽  
Vehicle Systems ◽  
Time Required

Abstract The US Army Tank-automotive and Armaments Command (TACOM) has the mission of procuring and managing the US Army’s fleet of wheeled and tracked vehicles. TACOM’s Tank Automotive Research, Development and Engineering Center (TARDEC) provides engineering and scientific support directed at maximizing the capability of all Department of Defense (DOD) ground vehicle systems and ensuring the safety of their personnel. In order to reduce the time required to deploy troops and equipment, engineers and scientists at TARDEC have been investigating modifications to ground vehicles that lead to overall increases in performance, especially in the areas of off-road mobility, and on-road stability and handling. This paper describes an effort to assess the dynamic performance of a track laying (tracked) Recovery Vehicle towing a disabled tracked vehicle whose weight is approximately equal to that of the Recovery Vehicle. Specifically, this paper will describe techniques employed to develop a 3-dimensional dynamic model of the vehicle combination, and apply the model to evaluate towing performance of the recovery vehicle. It also describes measures aimed at minimizing incidences of jackknifing when braking on downhill slopes, as well as vehicle design modifications that were modeled and simulated in efforts to reduce the combination’s jackknife vulnerability. These modifications included tow bar schemes that locked-out inter-vehicle yaw, and external surge brakes mounted on the towed vehicle. Techniques used to model and simulate the tractive effort available to the Recovery Vehicle on varied soil types are described as are analyses used to determine the combination’s ability to climb grades. Vehicle modifications aimed at increasing the tractive effort available, such as tow bar pitch orientation and track shoe geometry changes are also described.

Seeded Fault Testing of Military Ground Vehicles as a Pathway to Condition Based Maintenance

2010 ◽  
Author(s):  
Matthew J. Hillegass ◽  
Eric L. Rabeno
Keyword(s):  
System Analysis ◽  
Condition Based Maintenance ◽  
Engine Oil ◽  
Actual Condition ◽  
Material System ◽  
Fault Testing ◽  
Ground Vehicle ◽  
Us Army ◽  
The Us ◽  
Vehicle Systems

The performance of military ground vehicle systems is being degraded due to high operation tempo and exposure to extreme environments while performing in-theater service. To address this issue, the US Army is implementing a policy of Condition Based Maintenance which is supported by the Army Material System Analysis Activity (AMSAA). The vision of this policy is to base the maintenance of systems upon the actual condition of the system and not upon time- or distance-based schedules. This capability will be enabled by the application of usage, diagnostic and prognostic processes executed on a Health and Usage Monitoring System (HUMS) installed on these vehicle systems. A thorough understanding of the ways in which the system condition is degenerated and the ability of the HUMS to detect, identify, and communicate all conditions that require maintenance in a timely manner are key requirements of these processes. Seeded Fault Testing is the critical means of fulfilling these requirements. A joint Seeded Fault Testing project between AMSAA and the US Army Aberdeen Test Center (ATC) has been initiated to gain a thorough understanding of ground vehicle system condition degeneration and HUMS implementation of products and processes that can accurately identify and communicate it. A military vehicle underwent exhaustive testing in support of this project. The vehicle was subjected to specific use scenarios while carefully controlled faults are induced in engine, transmission, and other key mechanical subsystems that would degrade vehicle performance and degenerate system condition. The vehicle’s induced faults included lowered coolant levels to simulate leakage, restriction of air flow across radiators and filters to simulate dust and debris accumulation, and lowered transmission and engine oil levels to simulate leakage and usage. The objective of this project was to use the results from the seeded fault tests to establish critical thresholds, trends, and patterns that will be the basis of the creation and implementation of real-time HUMS-based algorithms that predict faults, warn operators and maintainers of imminent failures, and provide a sound foundation for Condition Based Maintenance.

Virtual Proving Ground Simulation for Vehicle Design

1998 ◽  
Author(s):  
Edward J. Haug ◽  
James Cremer ◽  
Yiannis Papelis ◽  
Dario Solis ◽  
R. Ranganthan
Keyword(s):  
Driving Simulator ◽  
Vehicle Design ◽  
Department Of Transportation ◽  
University Of Iowa ◽  
Ground Vehicle ◽  
Engineering Level ◽  
Time Simulation ◽  
The Us ◽  
Subsystem Design ◽  
The University

Abstract Emerging ground vehicle driving simulation technologies and simulator capabilities are presented, which establish the foundation for a fundamentally new vehicle virtual proving ground suitable for vehicle system and subsystem design. Engineering level of fidelity modeling capabilities, previously used in Computer-Aided Engineering for vehicle design, are extended to real-time simulation with the driver-in-the-loop for highly realistic virtual proving ground simulation. Capabilities of the National Advanced Driving Simulator, being developed by the US Department of Transportation and The University of Iowa are presented, and advanced simulation technologies required for the envisioned virtual proving ground capability are summarized. This paper sets the stage for technical papers presented in a Special Session of the 1998 ASME Design Automation Conference on Virtual Proving Ground Simulation.

Function-Oriented Material Design for Next-Generation Ground Vehicles

2003 ◽  
Author(s):  
Zheng-Dong Ma ◽  
Hui Wang ◽  
Noboru Kikuchi ◽  
Christophe Pierre ◽  
Basavaraju Raju
Keyword(s):  
Cost Effective ◽  
Material Design ◽  
Optimization Process ◽  
Ground Vehicles ◽  
Ground Vehicle ◽  
Cost Constraints ◽  
Vehicle Systems ◽  
Optimal Material ◽  
Material Layout ◽  
Oriented Material

A systematic approach, referred to as function-oriented material design (FOMD), is presented in this paper, which can be used to design materials for the specific tasks demanded of structures in future ground vehicle systems. In order to carry out the FOMD process, first the functions of a structure in the vehicle system need to be explicitly defined in a systematic way. Then these functions must be quantified, so as to define the objective and constraint functions in the optimization process. Finally, an advanced optimization process needs to be carried out, and the material layout has to be finalized by the design engineer. Typically a number of constraints, such as manufacturing and cost constraints, need to be considered in the optimal material design process. A major objective of this research is to outline these constraints, as well as to find ways to ameliorate the optimization process to produce improved, cost-effective, and manufacturable engineered materials.

Stochastic Modeling in Multibody Dynamics: Aerodynamic Loads on Ground Vehicles

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Christian Wetzel ◽  
Carsten Proppe
Keyword(s):  
Probability Density Functions ◽  
Sensitivity Analyses ◽  
Ground Vehicles ◽  
Vehicle Model ◽  
Ground Vehicle ◽  
Aerodynamic Loads ◽  
Vehicle System ◽  
Surface Method ◽  
Vehicle Systems ◽  
Reliability Methods

The influence of wind loads on the driving behavior of ground vehicles is an important economical, safety, and comfort issue. The crosswind performance is of great interest, as violent lateral winds can cause major accidents or will at least make the driver and the passengers feel very uncomfortable and insecure. In this paper, a sampling based methodology for the analysis of stochastic ground vehicle systems is presented. Starting from the well known Monte Carlo method more sophisticated reliability methods with higher efficiency are introduced and their advantages and drawbacks are critically reviewed. Furthermore, probabilistic sensitivity analyses are presented, which can be used to quantify the importance of the random variables on the response of the vehicle system. The influence of the parameters of the probability density functions is investigated by means of a novel response surface method. The mentioned approach is applied to a nonlinear road vehicle model under strong crosswind excitation for which the failure probabilities and the sensitivities are computed.

The Use of Modeling and Simulation in Ground Vehicle Analysis

2001 ◽  
Author(s):  
Michael D. Letherwood ◽  
David D. Gunter
Keyword(s):  
Life Cycle ◽  
Modeling And Simulation ◽  
Dynamic Performance ◽  
Ground Vehicles ◽  
Reform Initiatives ◽  
Ground Vehicle ◽  
Acquisition Strategies ◽  
Simulation Based ◽  
Acquisition Reform ◽  
And Performance

Abstract In support of Department of Defense (DOD) mandated acquisition reform initiatives to reduce vehicle related life cycle costs and timelines, the Tank-automotive and Armaments Research, Development and Engineering Center (TARDEC) is using simulation-based acquisition strategies to investigate the dynamic performance of wheeled and tracked ground vehicles. These strategies are used throughout the vehicle development, testing, and fielding life cycle process. The paper will describe how modeling and simulation (M&S) is applied to answer a wide variety of design and performance evaluation questions. It will also depict a series of simulation-based engineering projects that build on the Army’s simulation investments as a tool to investigate and answer real-world vehicle design, acquisition, and engineering support questions.

Multibody Modeling of Vehicles in a Virtual Prototyping Environment

1995 ◽  
Author(s):  
Kishore Sai Vejju ◽  
Jeffrey S. Freeman
Keyword(s):  
Driving Simulator ◽  
System Modeling ◽  
Virtual Prototyping ◽  
Vehicle Body ◽  
Multibody Modeling ◽  
Modeling Tool ◽  
Ground Vehicle ◽  
Us Army ◽  
The Us ◽  
Kinematic Models

Abstract This paper presents concepts involved in the theory and implementation of a vehicle body and suspension modeling tool as part of the software development for the National Advanced Driving Simulator (NADS). The NADS will be a state-of-the-art, operator-in-the-loop ground vehicle simulator, which can be applied to both human factors and vehicle virtual prototyping studies. By applying the modeling tool developed in this study, vehicle kinematic models can be easily created and tested, either using off-line engineering analysis packages or using operator-in-the-loop simulators, such as the NADS. Vehicles are complex systems containing multiple bodies, joints and force generating elements. Manually modeling these systems for kinematic and/or dynamic analysis is tedious and prone to errors. This creates a need for a modeling tool which reduces modeling time, increases modeling accuracy and is easy to use. This paper discusses the concepts involved in developing a modeling tool for the topology analysis and assembly of the multibody vehicle model. Suspension system modeling is briefly described, along with an example employing the US Army HMMWV vehicle.

Neuro-Optometric Treatment of Complications from a Cerebellar Astrocytoma

2020 ◽  
pp. 304-312
Keyword(s):  
Visual System ◽  
Common Site ◽  
Us Army ◽  
Cranial Nerve Palsies ◽  
Pilocytic Astrocytomas ◽  
The Us ◽  
Extent Of Damage ◽  
Functional Components ◽  
The Brain

Background: Insult to the brain, whether from trauma or other etiologies, can have a devastating effect on an individual. Symptoms can be many and varied, depending on the location and extent of damage. This presentation can be a challenge to the optometrist charged with treating the sequelae of this event as multiple functional components of the visual system can be affected. Case Report: This paper describes the diagnosis and subsequent ophthalmic management of an acquired brain injury in a 22 year old male on active duty in the US Army. After developing acute neurological symptoms, the patient was diagnosed with a pilocytic astrocytoma of the cerebellum. Emergent neurosurgery to treat the neoplasm resulted in iatrogenic cranial nerve palsies and a hemispheric syndrome. Over the next 18 months, he was managed by a series of providers, including a strabismus surgeon, until presenting to our clinic. Lenses, prism, and in-office and out-of-office neurooptometric rehabilitation therapy were utilized to improve his functioning and make progress towards his goals. Conclusions: Pilocytic astrocytomas are the most common primary brain tumors, and the vast majority are benign with excellent surgical prognosis. Although the most common site is the cerebellum, the visual pathway is also frequently affected. If the eye or visual system is affected, optometrists have the ability to drastically improve quality of life with neuro-optometric rehabilitation.

EDUCATIONAL-TRAINING FACILITIES OF GROUND US FORCES

2019 ◽  
pp. 168-176
Author(s):  
D.B. Izyumov ◽  
E.L. Kondratyuk
Keyword(s):  
United States ◽  
Armed Forces ◽  
The United States ◽  
Educational Training ◽  
Us Army ◽  
The Us ◽  
Level Of Training ◽  
Army Personnel

The article discusses issues related to the development and use of training means and facilities in order to improve the level of training of US Army personnel. An overview of the main simulators used in the US Armed Forces at present is given, and the prospects for the development of the United States in this area are presented.

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