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White Paper

REDUCING DOWNTIME THROUGH THE USE OF PREDICTIVE ANALYTICS AND TECHNICAL TRAINING ADVANCEMENTS

2018-01-05
WP-0007
The exponential increase in the number of aircraft and air travelers has triggered new innovations aimed to make airline services more reliable and consumer friendly. Quick and efficient maintenance actions with minimum downtime are the need of the hour. Another major challenge is ensuring maintenance personnel are trained effectively; technology like augmented reality and Virtual Maintenance Trainers (VMTs) may provide safe and efficient training in lieu of live, instructor-led arrangements. And while traditional User/Maintenance Manuals provide useful information when dealing with simple machines, when dealing with complex systems of systems and miniaturized technologies, like unmanned aerial vehicles (UAVs), new technologies like augmented reality can rapidly and effectively support the maintenance operations.
Technical Paper

Modeling of Engine Warm-Up with Integration of Vehicle and Engine Cycle Simulation

2001-05-14
2001-01-1697
The incorporation of a detailed engine process calculation that takes into account thermal behavior of the engine and exhaust system is essential for a realistic simulation of transient vehicle operation. This is the only possible way to have a precise preliminary calculation of fuel consumption and emissions. Therefore, a comprehensive thermal network of the engine based on the lumped capacity method has been developed. The model allows the computation of component temperatures in steady state operation as well as in transient engine studies, e.g. investigations of engine warm-up. The model is integrated in a co-simulation environment consisting of a detailed vehicle and engine cycle simulation code. The paper describes the procedure of the co-simulation and presents several examples of warm-up simulations.
Technical Paper

Progress in the Optimized Application of Simulation Tools in Vehicle Air Conditioning

2001-05-14
2001-01-1699
The paper focuses on the usage of simulation tools during the development of vehicle air-conditioning systems. The integration of simulation is explained at every stage of the process. It differentiates at which step the 3-D simulation properties are needed and where the advantages of 1-D tools decide its use. For each demand the most targeting way of calculation has to be chosen, facing properties like precision, hardware needs and especially modeling as well as calculation time along to the tightened development schedule. Examples are given from system layout to detailed optimization.
Technical Paper

Design and Transient Simulation of Vehicle Air Conditioning Systems

2001-05-14
2001-01-1692
This paper describes the need for dynamic (transient) simulation of automotive air conditioning systems, the reasons why such simulations are challenging, and the applicability of a general purpose off-the-shelf thermohydraulic analyzer to answer such challenges. An overview of modeling methods for the basic components are presented, along with relevant approximations and their effect on speed and accuracy of the results.
Technical Paper

Road Vibration Investigation Using the Ford Vehicle Vibration Simulator

2001-04-30
2001-01-1572
In-vehicle subjective evaluations of a mid-sized SUV exhibited an objectionable vibration character when driven over smooth road surfaces with minor rolling irregularities. As a result, a project was initiated to systematically identify problem frequency components and degrees-of-freedom that contribute to the phenomenon sometimes referred to as “nervousness.” The Ford Vehicle Vibration Simulator (VVS) was used to simulate the vibrations felt on the road. Eleven degree-of-freedom (DOF) simulations were produced. The seat simulation contained three translational (vertical, lateral and longitudinal) and three rotational (pitch, yaw and roll) DOFs. The steering wheel consisted of all three translational components in addition to the DOF associated with wheel rotation. The floorpan was excited in the vertical direction only. By systematically eliminating various DOFs, it was determined that the seat contributed the most to the objectionable vibration.
Technical Paper

Some Factors in the Subjective Evaluation of Laboratory Simulated Ride

2001-04-30
2001-01-1569
Effects of DOF and subjective method on evaluations of ride quality on the Ford Vehicle Vibration Simulator were studied. Seat track vibrations from 6 vehicles were reproduced on the 6 DOF seat shaker in a DOE with pitch and roll as factors. These appeared in two evaluations of ride/shake; semantic scaling by 30 subjects of 6 vehicles, and paired comparisons by 16 of the subjects on 3 of the vehicles. Both methods found significant vehicle, pitch and roll effects. Order dependence was shown for semantic scaling. The less susceptible paired comparison method gave a different ordering, and is thus preferred.
Technical Paper

Subjective Evaluation of NVH CAE Model Predictions Using an Operator-in-the-Loop Driving Simulator

2001-04-30
2001-01-1590
In the past several years there has been a significant effort to increase the reliance on CAE technology to guide the vehicle design process, with the accompanying effort to reduce or eliminate vehicle prototype testing during the early design phase. Since little or no representative hardware is available early in the design, a tool is needed which allows NVH Development Engineers to subjectively experience the results of NVH CAE model predictions in a realistic driving environment. This paper documents the development of a high fidelity NVH simulator, including both audio and vibration, and the integration of this simulator into an “operator-in-the-loop” Driving Simulator. The key development of this system is its ability to incorporate NVH CAE predictions into the simulated driving environment.
Technical Paper

“Digital Prototype” Simulations to Achieve Vehicle Level NVH Targets in the Presence of Uncertainties

2001-04-30
2001-01-1529
“Digital Prototype” simulations have been used at DaimlerChrysler to achieve vehicle level NVH objectives. The effectiveness of these simulations to guide the design when faced with vehicle parameter uncertainties is discussed. These uncertainties include, but are not limited to, material properties, material gauges, damping, structural geometry, loads, boundary conditions and weld integrity. Manufacturing and assembly processes introduce variations in the nominal values of these parameters resulting in a scatter of vehicle level NVH simulation responses. An example of a high frequency NVH concern will be studied and modified to arrive at robust design guidance when faced with uncertainty. The validity of a “deterministic digital prototype” simulation model and its relevant role as a “trend predictor” rather than “absolute predictor” tool in guiding the design is also discussed.
Technical Paper

The Application of Direct Body Excitation Toward Developing a Full Vehicle Objective Squeak and Rattle Metric

2001-04-30
2001-01-1554
In order to engineer Squeak & Rattle (S&R) free vehicles it is essential to develop an objective measurement method to compare and correlate with customer satisfaction and subjective S&R assessments. Three methods for exciting S&Rs -type surfaces. Excitation methods evaluated were road tests over S&R surfaces, road simulators, and direct body excitation (DBE). The principle of DBE involves using electromagnetic shakers to induce controlled, road-measured vibration into the body, bypassing the tire patch and suspension. DBE is a promising technology for making objective measurements because it is extremely quiet (test equipment noise does not mask S&Rs), while meeting other project goals. While DBE is limited in exposing S&Rs caused by body twist and suspension noises, advantages include higher frequency energy owing to electro-dynamic shakers, continuous random excitation, lower capital cost, mobility, and safety.
Technical Paper

Interior Noise Simulation for Improved Vehicle Sound

2001-04-30
2001-01-1539
In the recent past, interior noise quality has developed into a decisive aspect for the evaluation of overall vehicle quality. At most operating points, the dominating interior noise share is generated by the powertrain. Interior noise simulation is a new tool for upgrading interior noise. Based on measurements of air- and structure-borne noise excitations caused by the powertrain, the interior noise shares are determined by applying the properties of the transfer paths. By superimposing the individual interior noise shares, the overall interior noise can be predicted. Well before the engine is operated in the vehicle for the first time, annoying interior noise shares, their causes and their transfer paths can be identified by subjective and objective analysis. This enables the engineer to focus on vital optimization measures as to excitations occurring at the engine as well as to transfer paths in the vehicle.
Technical Paper

Automatic Detection of Buzz, Squeak and Rattle Events

2001-04-30
2001-01-1479
In the world of BSR (Buzz, Squeak and Rattle) testing, there is a high level of sophistication regarding the test machines employed to excite the items under test as well as the techniques used to ensure that the test is representative of real-life operating conditions. However, the object of the measurements, i.e., the identification of transient acoustic events classified as Buzz, Squeak or Rattle, is mostly a subjective procedure with classification in terms of Sound Pressure Level in dB(A) or Stationary Loudness. These “standard” metrics have proven, in general, unreliable in assessing the importance of individual transient events, and inappropriate to describe the vehicle signature from a BSR standpoint.
Technical Paper

THE MORIS MOTORCYCLE SIMULATOR: AN OVERVIEW

2001-12-01
2001-01-1874
1 Many motion based simulators have been developed in the last thirty years for many different types of vehicles [1] [2]. In order to make a simulation more realistic, linear accelerations and angular rates are exerted on the pilot by moving the platform on which the mock-up vehicle is located. The purpose of this article is to present a 7 DOFs (vertical, lateral and longitudinal displacements, roll, pitch and yaw angles and steer) motorcycle simulator which has been realized in Pisa, Italy, in the framework of the Esprit project by a consortium composed by industrial partners (Piaggio and Humanware from Italy and HEAD acoustics from Germany) and by academic partners (Scuola Superiore S. Anna from Italy, Halmstad University from Sweden and University of Bochum from Germany).
Technical Paper

TRACTOR PLOWING SPEEDS

1920-01-01
200018
Among the problems before the designers of plowing tractors, none is more important than that of ascertaining the most economical plowing speed at which to operate a tractor to give first-class work at a minimum cost. The solution must be right from both the maunfacturer's and the farmer's standpoints. A variety of soil resistances, different speeds, widths and depth of cut, types and shapes of plows must be considered. The recently published draft data of Professor Davidson of Iowa State College and those of the Kansas State Agricultural College are used. They indicate in general that in each kind of soil, whether heavy or light, with speed increase there is a corresponding increase of draft, the amount of which is dependent upon the speed, shape of plow and nature of soil. The further experiments made relative to increased speed and draft and to the area plowed at different speeds are described and discussed, the results being shown by charts.
Technical Paper

Vertical vehicle dynamics on soft ground~Investigations with FEM

2000-06-12
2000-05-0393
The Finite Element Method (FEM) has proved to be a suitable tool for the investigation of wheel-soil interaction. Compared to analytical models, the FEM presents numerous advantages. The sinkage and the deflection of the wheel, the pressure distribution in ground, the motion of the soil and especially the contact shape between the elastic wheel and the deformed soil are gained as simulation results. Moreover, the soil compaction in the depth can be visualized. Using the FEM, effects have been investigated so far with the interaction between a single wheel and soft soil. Because of the change of the ground contour due to the dynamical wheel-loads, depending on the vehicle oscillation, the influence from the pitching and vertical oscillating vehicle has to be considered. Therefore the well-known FEM-based simulation concept VENUS is extended to VENUS-DYN (DYNamic VEhicle NatUre Simulation), that includes a two-dimensional model of a complete vehicle interacting with soft ground.
Technical Paper

Structuring Neural Network Driver Model and Analyzing Its Characteristics

2000-06-12
2000-05-0376
Using the results of lane-change tests performed on a driving simulator, driver models were developed by means of a neural-network system. Several kinds of driver visual information were used as input data for structure of the neural network, and the steering angle was employed as learning information. A series of simulations employing the trained neural network was conducted to determine the allowable ranges of initial vehicle position, velocity, stability factor, and other variables for successful lane-change maneuvers and for stable running against side winds.
Technical Paper

Driver → vehicle behavior → intelligent vehicle

2000-06-12
2000-05-0377
In this article, the authors try to get their own contribution for solving any actual problems in vehicle stability and handling framework. It used submodeling techniques for entire dynamic mechanical system. Fuzzy modeling is used for one realistic description of dynamic mechanical system represented by vehicle. It applied one solving algorithm of fuzzy relational equations, having genetics algorithm support technique. Finally, it construct one neural network will be fast learning from relations equations solutions. The online work is required approximate equal with driver behavior.
Technical Paper

Simulator for forward collision warning and avoidance system

2000-06-12
2000-05-0364
This paper presents a simulator for Forward Collision Warning and Avoidance (FCWA) system. The proposed simulator is composed of a personal computer as a controller, a 24 GHz radar, a warning and brake lamp, a buzzer and a lead vehicle model which is driven by two AC servo motors. A FCWA algorithm determines the warning and braking headway distance by road surface condition (wet/dry), following vehicle velocity, and relative velocity. The simulator has been designed and used to test a FCWA algorithm under realistic operating conditions in the laboratory. Even failure situations which would normally not be feasible for real vehicle test can be tested in the simulator.
Technical Paper

A multi-vehicle platoon simulator

2000-06-12
2000-05-0363
This paper presents a real-time vehicle powertrain simulator and a pseudo real-time multi-vehicle platoon simulator. The developed powertrain simulator simulates the complex vehicle powertrain dynamics, including detailed shifting transients, in the PC environment in real time. The driver input is provided using a throttle pedal interfaced using the game port. The processor requirements vary depending on the simulation options selected. In the basic version, this requirement is only approximately 20% of a 300 MHz Pentium II- based PC. For multi-vehicle platoon simulation, a network configuration is proposed. It links several individual powertrain simulations via the TCP/IP network. This network platoon simulation is also linked to a server which graphically displays the multi-vehicle platoon operation. In this network configuration, due to a random delay in data transfer the simulation time kernel is made to lag real time.
Technical Paper

The development of warm-up control strategies for a methanol reformer fuel cell vehicle

2000-06-12
2000-05-0330
A fuel-cell-powered vehicle requires a plentiful supply of hydrogen to achieve good performance. This can be produced from methanol via an on-board reformer and gas clean-up unit. Since the reformer can take several minutes to reach its operating temperature, it is initially necessary to provide an alternative power source, such as a battery or ultra-capacitor, in order to drive the vehicle. This paper describes the use of a fuel cell vehicle simulation to predict behavior over a drive cycle from a cold start and to evaluate different warm-up control strategies in terms of performance and fuel efficiency.
Technical Paper

Optimization of heat management of vehicles using simulation tools

2000-06-12
2000-05-0342
Heat management must allow the adjustment of optimal operating temperatures of all components of a vehicle. A comprehensive simulation model (KULI) will contain all components relevant for heat management. This includes heat sources, heat exchangers, fans, etc. Main aspects of the simulation are flow and heat transfer analysis. Not only the engine cooling system can be covered with this simulation tool, also the air-conditioning circuit including phase changing models is a part of it (KULI AC). To fulfill the needs of integrating various software tools to an overall simulation cluster an interface to a fluid flow 1-dimensional software (FLOWMASTER) was developed. The use of 1- dimensional methods and mesh flow theory for modeling the underhood air flow of vehicles is very efficient method. For complex flow patterns however it is desirable to use CFD analysis.
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