Browse Topic: Four wheel drive

Items (79)

High Speed Driveline Power Loss & Influencing Factors

2024-26-033701/16/2024

Energy savings in automotive applications has always remain an important aspect of research. In addition, today's highspeed requirements in electric vehicles require high-efficiency drivelines to match overall vehicle mileage or range. This paper presents the validation of the overall efficiency & drag losses of the highspeed Driveline for an ATV with 4 Wheel Drive System. The efficiency & drag losses were measured in the powertrain testbed where the test units were placed between two Transient Dynamometers. The main aim of the test was to validate the overall efficiency as a function of input speed and torque. All these measured values of the gearbox efficiency are included in various graphs. The tests were performed for complete functional range of UUT at max. operating oil temperatures for Transmission and Front Differential testing. Drive shafts tests were performed at its complete range and various inclination angle up to max. failure point. The Wheel Hub was tested at various

Jain, Sankalp, Singh, Parminder

Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle

15-17-01-0003

09/23/2023

Abstract A valuable quantity for analyzing the lateral dynamics of road vehicles is the side-slip angle, that is, the angle between the vehicle’s longitudinal axis and its speed direction. A reliable real-time side-slip angle value enables several features, such as stability controls, identification of understeer and oversteer conditions, estimation of lateral forces during cornering, or tire grip and wear estimation. Since the direct measurement of this variable can only be done with complex and expensive devices, it is worth trying to estimate it through virtual sensors based on mathematical models. This article illustrates a methodology for real-time on-board estimation of the side-slip angle through a machine learning model (SSE—side-slip estimator). It exploits a recurrent neural network trained and tested via on-road experimental data acquisition. In particular, the machine learning model only uses input signals from a standard road car sensor configuration. The model

Giuliacci, Tiziano Alberto, Ballesio, Stefano, Fainello, Marco, Mair, Ulrich, King, Julian

Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle

15-17-01-0003-TEST-REC09/23/2023

Giuliacci, Tiziano Alberto, Ballesio, Stefano, Fainello, Marco, Mair, Ulrich, King, Julian

Magna execs warns on impending EV complexities

21AUTP02_1002/01/2021

The industry's transition to electrified - and ultimately, fully electric vehicles (EVs) is bringing far greater overall complexity in product development and technology-management, according to Magna Powertrain executives speaking in an online media session during mid-January's CES 2021 virtual trade show. Magna's traditional strengths in lightweight structures, driver-assistance sensor technologies, active aerodynamic systems, powertrain/drivelines and full-vehicle assembly serve as the foundation for the company as it moves further into vehicle electrification and automated-driving solutions, noted Sherif Marakby, the company's recently hired executive VP. Markaby is a veteran leader of Ford's hybrid and EV programs and headed the automaker's Team Edison autonomous R&D group before joining Magna.

Brooke, Lindsay

Holistic hydraulic designs add more sensors, controls

19TOFHP08_0708/01/2019

Hydraulic system developers are moving on many different fronts as they strive to improve performance and efficiency. A full-system approach that includes more sensors and advanced controls is helping design teams reduce component counts without sacrificing performance. The multifaceted design challenges of today's equipment are forcing engineers to take a broad view of the vehicle and its systems in order to get the most from valves, electronics, pumps and other equipment. Customer expectations and regulatory requirements are both rising, forcing engineers and planners to examine every element of a design.

Costlow, Terry

Volvo CE sees major efficiency gain from hybrid-electric wheel loader

17TOFHP10_1210/01/2017

Volvo Construction Equipment partnered with Waste Management (WM), the California Energy Commission and CALSTART to put its LX1 prototype electric hybrid wheel loader to the test: field test, that is. The company showcased the LX1 at a media event in July at WM's Redwood Landfill in Novato, CA. Made up of 98% new parts, the LX1 prototype series hybrid has a fundamentally new machine design. It incorporates a driveline that consists of electric-drive motors mounted at the wheels, electric-driven hydraulics, a battery energy storage system, a significantly smaller diesel engine and new machine architecture including a new design of the lifting unit.

Shuttleworth, Jennifer

The Dual Phase Twin Synchronous Belt Drive

2017-01-177306/05/2017

The dual phase twin synchronous drive has been developed for belt noise reduction. Two identical synchronous belts are arranged parallel side by side with one tooth staggered against other by the half pitch offset. The noise cancellation effect is achieved as one belt tooth engagement coincides with the other belt tooth dis-engagement. A center flange is used as a divider to prevent the belts contacting each other along the axial direction during their entrance and exit of the sprocket. An overall 20 [dBA] noise reduction has been achieved with the dual phase twin belt drive compared to an equal width single belt counterpart. The vibration amplitude of the hub load is also reduced which is directly correlated to the structural borne noise. Comparing to the related dual phase helical tooth belt, the dual phase twin belt is superior in torque carrying capability; and is on par with noise mitigation. The dual phase twin belt has been demonstrated with the automotive transfer case

Yuan, Jing

Design and Development of All Terrain Hybrid Vehicle for Scientific Expedition

2016-28-017602/01/2016

The hybrid robot, will be a battery operated four wheel drive vehicle with a rigid chassis for all terrain operation. The vehicle will be suited for various payloads based on applications with geological, atmospheric sensors such as oxygen measurement, glacier thickness measurement, CO2 measurement, thermal properties measurement, salinity, buried object identification at a depth of 8 to 100 m., etc . The vehicle will be remotely controlled through a RF signal which allows it to maneuver up to 5 km. The novelty of the design, is its capability for all terrain and ease of trafficability based on skid steering, self alignment of sensors and vehicle traction in spite of possible inverted conditions and the vehicle can travel from land, snow, water and vice versa. The vehicle can be used in survey at coastline of water bodies, borderlines and can also be extensively used in polar region for studying glacier aging and as advance vehicle for the convoys and polar mapping.

Siva, Rajesh, Janarthanan, C., Muthuvel, P., Kuttikrishnan, Gopkumar, Ramadass, Gidugu, Atmanand, Malayath

A Novel Hierarchical Global Chassis Control System for Distributed Electric Vehicles

2014-01-009104/01/2014

The current global chassis control (GCC) frequently makes use of decoupled control methods which depend on driving condition partition and simple rule-based vertical force distribution, and are insufficient to obtain optimal vehicle dynamics performance. Therefore, a novel hierarchical global chassis control system for a distributed electric vehicle (DEV), which is equipped with four wheel driving/steering and active suspension systems, is developed in this paper. The control system consists of three layers: in the upper layer, the desired forces/moments based on vehicular driving demands are determined; in the middle layer, a coordinated control method of longitudinal/lateral/vertical tire forces are proposed; in the lower layer, the driving/steering/suspension control is conducted to realize each distributed tire force. As the most outstanding contribution of this paper, a non-convex optimization problem with multiple constraints for coordinated control of longitudinal/lateral

Luo, Yugong, Cao, Kun, Dai, Yifan, Chu, Wenbo, Li, Keqiang

Powertrain Integration and Controls Development Process for a Parallel Through the Road Plug-in Hybrid Electric Vehicle

2014-01-191704/01/2014

The University of Washington Advanced Vehicle Works team has spent the last two years designing and integrating a Parallel Through The Road (PTTR) PHEV drive system into a stock Chevy Malibu as part of the EcoCAR 2 Advanced Vehicle Technology Competition. This paper presents the integration efforts performed throughout year 2 in an effort to produce a 65% “buyoff ready” prototype vehicle. EcoCAR2 challenges 16 universities across North America to reduce the environmental impact of a 2013 Chevrolet Malibu without compromising consumer acceptability. The architecture chosen by the team to address these goals is a PTTR PHEV which provides all-electric operation to displace petroleum usage, four wheel drive mode to improve utility performance for consumers, and an efficient charge-sustaining mode using 20% biodiesel (B20). The PTTR architecture is the lowest cost architecture to provide all of these benefits, and it does so without compromising the safety or performance of the platform.

Crain, Trevor, Wilke, Joshua, Boyer, Brendan, Fayer, Trevor, Fabien, Brian, Reinhall, Per

Development of a Parallel through the Road Plug-In Hybrid Electric Vehicle

2012-01-176709/10/2012

The University of Washington Advanced Vehicle Works team is currently in the process of designing Plug-in Hybrid Electric Vehicle (PHEV) for the EcoCAR2 Challenge. This competition challenges 15 universities across North America to reduce the environmental impact of a 2013 Chevrolet Malibu without compromising consumer acceptability. The architecture chosen by the team to address these goals is a Parallel Through The Road (PTTR) PHEV which provides all electric operation to displace petroleum usage, four wheel drive mode to improve utility performance for consumers, and effective charge-sustaining operation. The PTTR architecture is the lowest cost architecture to provide all of these benefits, and it does so without compromising safety performance of the platform. This paper presents the VTS development process, architecture selection process, component selection process and design of a vehicle with particular emphasis on the unique or novel approaches used to solve any design

Fayer, Trevor, Crain, Trevor, Wurden, Richard, Wilke, Joshua, Fabien, Brian

Soil Stress State Under Loads of Commercial Vehicles

2011-01-217309/13/2011

The paper contains experimental results of soil stress state under loading of commercial wheeled vehicles. The measurements were performed with the use of SSTs (Stress State Transducers), which enable to determine soil pressures needed for calculations of stress state at a point: principal stresses and their direction cosines as well as octahedral stresses. A detailed description of the measuring method with an introductory theory of operation of the SST together with some methodology aspects of soil pressure measurements are included. The field tests were conducted on three different soil surfaces: loess, sand and turf as well as on snow surface in winter conditions. For the tests, two vehicles were used: a 5,6T 4x4 truck and a 14T 6x6 truck. The vehicles were driven at constant low speed or at different speeds. Moreover, effects of wheel loading, reduced inflation pressure, drive modes (rolling or driving) were also analyzed. The results are presented partially in a form of stress

Pytka, Jaroslaw

Distribution Method of Front/Rear Wheel Side-Slip Angles and Left/Right Motor Torques for Range Extension Control System of Electric Vehicle on Curving Road

2011-39-720805/17/2011

In this paper, the range extension control system based on least square method is proposed for electric vehicles with in-wheel motors and front active steering. This proposed method distributes front and rear wheel side-slip angles and driving force difference between left and right motors from lateral force and yaw-moment. The proposed method enables to reduce driving resistance generated from front steering angle. In fact, the mileage per charge is extended up to 200 m/kWh. Simulations and experiments are carried out to confirm the effectiveness of the proposed method.

Sumiya, Hayato, Fujimoto, Hiroshi

The Technology and Economics of In-Wheel Motors

2010-01-230710/19/2010

Electric vehicle development is at a crossroads. Consumers want vehicles that offer the same size, performance, range, reliability and cost as their current vehicles. OEMs must make a profit, and the government requires compliance with emissions standards. The result - low volume, compromised vehicles that consumers don't want, with questionable longevity and minimal profitability. In-wheel motor technology offers a solution to these problems; providing power equivalent to ICE alternatives in a package that does not invade chassis, passenger and cargo space. At the same time in-wheel motors can reduce vehicle part count, complexity and cost, feature integrated power electronics, give complete design freedom and the potential for increased regenerative braking (reducing battery size and cost, or increasing range). Together, these advantages create the tipping point for OEM acceptance of in-wheel-motor technology, offering them an immediate opportunity to build larger electric and hybrid

Watts, Andy, Vallance, Andrew, Whitehead, Andrew, Hilton, Chris, Fraser, Al

The Technology and Economics of In-Wheel Motors

2010-01-2307-TEST-REC10/19/2010

Watts, Andy, Vallance, Andrew, Whitehead, Andrew, Hilton, Chris, Fraser, Al

Upgrade of the Volvo Cars Aerodynamic Wind Tunnel

2007-01-104304/16/2007

The aerodynamic wind tunnel at Volvo Cars, known as the PVT, was recently upgraded to a moving ground wind tunnel to improve simulation quality. The moving ground simulation system consists of a 5-belt rolling road system (a centre belt and four wheel drive units). Flow simulation has also been improved by a new boundary layer control (BLC) system with a basic suction scoop, large distributed suction areas and aft belt tangential blowing. In addition, the wind tunnel main fan motor has been up-graded from 2.3 MW to 5 MW to provide a wind speed of 250 km/h in the full test section. Previously, 250 km/h was achieved only by installing inserts to reduce the test section area. The present paper provides an outline of the design features, philosophy of the new systems, aerodynamic calibration and commissioning results.

Sternéus, Johan, Walker, Tim, Bender, Trevor

Stochastic Modeling of a Four Wheel Drive Loader Linkage

2006-01-349610/31/2006

The manufacturing tolerances of off-highway machine linkages have an impact on linkage position during machine use. A study was undertaken to determine the extent of these tolerances on linkage position for standard machining tolerances of each linkage pin joint for a four wheel drive loader linkage. Linkage positions and distributions for each pin joint are shown in order to determine positional accuracy of the working tool connected to the linkage and impact to the machine loads. It is determined that the affect of the machining tolerances on this linkage have a very minor impact on the linkage position when the linkage is in new condition (before use) and the maximum variation in linkage actuation loads is less than 1% of nominal load.

Hindman, Jahmy, Burton, Richard, Schoenau, Greg

Quantifying the Change in Ride Height Due to Braking: Brake Dive Test Data

2006-01-156304/03/2006

The concept of brake dive is not new and most drivers are aware of this phenomenon. However, no known data is available to quantify the amount of change in vehicle height during braking. Often investigators involved in under-ride/over-ride collisions or relatively low speed collisions are faced with questions such as, “How much does the front bumper dip during braking?” or, “Is it likely that the relative bumper height mismatch is due to pre-impact braking?” This paper will provide the results of field testing aimed at providing answers to these and associated questions. The study will also review the factors that affect brake dive and the parameters under which these factors can be determined or be reasonably estimated. We consider how these factors can be used to predict the amount of change in bumper height.

Ray, Shawn P., Newbery, Trevor M., Koziol, John A.

Platform flexibility

AUTOFEB04_0802/01/2004

Once-rigid platforms transform into “shared components” that cut costs and boost flexibility. There was a time when manufacturers used a few vehicle platforms to create a variety of different models for a relatively low cost. The trouble was, the variety came mostly in the names of the different cars than from any substantial difference from one car to the next. That was because they shared so many components and so many hard points, such as suspension mounts, floorpans, and firewall cowl stampings, that the cars were barely distinguishable. Ford sold the Fox-platform-based Fairmont, Mustang, LTD, Thunderbird, Cougar, Capri, Marquis, and Mark VII. General Motors built a variety of closely related small, medium, and large J-, X-, and A -cars. At one point, virtually every car Chrysler sold was based on its K-car platform.

Carney, Dan

Development of a New Damping Matrices Identification Method and Its Applications

2001-01-140704/30/2001

An experimental method to identify damping characteristics of a dynamic system is reported. The method identifies damping matrices of the equation of motion of the system from measured frequency response functions, each different damping mechanism in a distinct matrix. Related experimental techniques and signal processing issues are discussed. Theoretical validation and error study are conducted by applying the method to a theoretical example. The method is applied experimentally to a thin beam with two different damping characteristics for experimental validation and demonstration of the method. Important advantages of the method over existing methods are explained.

Lee, Joon-Hyun, Kim, J., Grinker, Scott C.

Gear Shift Quality Improvement In Manual Transmissions Using Dynamic Modelling

2000-05-012606/12/2000

The importance of the gear shift quality of manual transmissions has increased significantly over the past few years as the refinement of other vehicle systems has increased. The synchroniser is often blamed as the cause of many shift quality issues. This is not always the case. The interaction of the entire selector system from the shift fork to the handball, the driveline and the transmission internals all play a part in the overall shift quality. The dynamic interaction of these systems at a component level is difficult to interpret by traditional test methods and virtually impossible at concept stage. To overcome these difficulties a dynamic model of the entire synchroniser, selector mechanism, driveline and transmission has been created. The model predicts the gearshift quality for a given set of input parameters, which can be correlated against test data. The model can then be used for parameter studies to investigate potential improvements to gearshift quality. The model can

Christopher Kent, David Kelly

The Last Great Miller: the Four-Wheel-Drive Indy Car

R-24406/01/2000

Utilizing an extraordinary historical archive, this book contains more than one hundred photos, as well as the text of over one hundred original letters (many written by Miller himself) about the car's development. The Last Great Miller brings to life the history of this unique model of race car.

Borgeson, Griffith

Improved Customer Satisfaction in Automotive Loudspeakers

2000-01-007703/06/2000

This paper shows various techniques used for improving customer satisfaction. The results are judged by independent surveys of customer responses obtained, at least one month after vehicle purchase. The Quality Tracking Survey (QTS) results are based on questions similar to nationally recognized car surveys, and are widely used to determine performance ranking. The vehicle under study was considered the worst performing in this category on initiation of this improvement effort. In less than two years, according to an independent survey, this vehicle finished the best of the group surveyed.

Klacza, Robert E.

Automotive Driveline System Engineering

2000-01-143901/15/2000

The trend in the automotive industry to include niche products with 4WD results in high development and investment cost for the manufacturer due to major changes to the platform and new technology. System suppliers for 4WD drivelines can help to reduce these costs significantly by developing “standardised” driveline concepts and taking on the responsibility for the layout, design, manufacture, assembly and validation of the system. A range of traction and handling improving limited slip devices as well as halfshafts and propshafts are available. They need to be integrated into the driveline system which then is being optimised with regard to system function, endurance and NVH.

Trommer, Jörg, Exner, Wolfgang

New Venture Gear 261 Transfer Case - A Robust Manual Shift Transfer Case

1999-01-126103/01/1999

The NV 261 part-time four-wheel-drive (4WD) transfer case was designed and developed by New Venture Gear (NVG) for the 1999 General Motor's GMT-800 light duty truck series. A modular system allows two separate models, a light duty (LD) and heavy duty (HD), to be built from one platform. Incorporated in the fully mechanical manual mode shift, two-wheel to four-wheel drive, a high capacity durable dual-cone synchronizer in combination with optimized friction reducing components are used in order to achieve shift effort requirements. Implementation of a fine-pitched chain, sprockets, and the use of magnesium cases achieved requirements for reduced noise levels and weight.

Dolan, Stephen M.

4WD Market Trends in Vehicles & the Adaptations of New Technology in the International Automotive Community

1999-01-126403/01/1999

This paper will show the trends in the 4 wheel drive vehicles, technologies, and the move to systems approach rather than the independent supplier approach. The trends show how the transfer case and other drive train components are changing using the latest technology. These changes are making more system adaptations possible. There are three directions that the current changes are moving into. 1) Continue to optimize current designs 2) Redesign with new devices and 3) Design new 4WD systems. Examples of future 4WD designs are Hybrid Electric Vehicles with motors at all four wheels, and CVT's. Specifically this paper will show the latest trends from 1994 to 1998 and some predictions into the future. The focus will be the U.S. Market but some references will be made to the world 4x4 market. Brief references will be made to the basics of traction and directional stability as they relate to the 4WD technology. The structure given in The 4WD Building Block Approach SAE Paper #952643 will

Williams, Randolph C.

Recycling of Automotive Seat Foam: Acoustics of Post Consumer Rebond Seat Foam For Carpet Underlayment Application

98009402/23/1998

A study was conducted to understand the acoustic viability of using post consumer rebond seat foam materials in vehicles for floor carpet underlayment applications. These foam materials were obtained from two different sources: 1) polyurethane foam dismantled from seats of end of life vehicles (ELV or scrap vehicles), and 2) polyurethane foam recovered and cleaned from auto shredder residue (ASR) by the Argonne National Laboratories (ANL) using their cleaning method. The study was conducted using three North-American cars, each serving different market segments. Based on both laboratory and on-road tests conducted on each vehicle, the study concluded that the acoustical performance of the floor carpet underlayment part made of post consumer rebond foam is comparable to that of the current production part mostly made of shoddy materials.

Saha, Pranab, Duranceau, Claudia M., Winslow, Gerald R.

All-Terrain Vehicle With Self-Righting and Pose Control

TBMG-3210802/01/1998

A small prototype robotic all-terrain vehicle features a unique drive and suspension system that affords capabilities for self righting, pose control, and enhanced maneuverability for passing over obstacles. The vehicle is designed for exploration of planets and asteroids, and could just as well be used on Earth to carry scientific instruments to remote, hostile, or otherwise inaccessible locations on the ground. The drive and suspension system enable the vehicle to perform such diverse maneuvers as flipping itself over, traveling normal side up or upside down, orienting the main vehicle body in a specified direction in all three dimensions, or setting the main vehicle body down onto the ground, to name a few. Another maneuver enables the vehicle to overcome a common weakness of traditional all-terrain vehicles — a limitation on traction and drive force that makes it difficult or impossible to push wheels over some obstacles: This vehicle can simply lift a wheel onto the top of an

A System of Evaluating After Market Four Wheel Drive Suspension Performance

97311512/31/1997

This paper describes a way to provide a more precise evaluation of the ride of after market suspension systems for four wheel drive vehicles. It explains the use of a Data Logging System and the Analysis of data retrieved by this system to set guidelines to aid in the development of new after market suspension (shock absorbers, springs, sway bars). The use of Data Logging Systems (used extensively on race cars in recent years) for this area of research will prove to be a valuable tool. A great deal of development time can be saved by utilising such a system.

Waugh, Gregory James

A New Concept and Technology Used in a Powershift Transmission for Off-Highway Vehicles

97275009/08/1997

A new powershift transmission concept for specific market segments of backhoe loaders and telescopic boom handlers has been designed, thoroughly lab and field tested and is now in full production. This new transmission is identified as the T16000. The concept is a result of extensive market analysis, customer interviews and study of vehicle performance requirements. OEM requirements in terms of reliability and quality have been considered. New technologies such as electronic modulation for directional clutches and electric/hydraulic modulation of the range clutches have resulted in an excellent shift quality vis-a-vis to application requirements and/or driver preference. A special protection system (mechanical) integrated in the control valve protects the transmission from engaging two clutches at the same time, preventing a drivetrain lock-up. All sensors are integrated in the valve body and are totally sealed according to European Standard IP67 specification. Adaptive control

Pecceu, Hendrik

Determining the Value of Vehicle Attributes Using a PC Based Tool

97076302/24/1997

Product engineers and product planners are routinely faced with trade-off decisions involving the cost of adding a product feature or modifying an existing feature versus its added value to the customer. The purpose of this paper is to assess the use of a personal computer (PC) for surveying respondents' willingness to pay (WTP) for four options - two-tone color, 4x4 drive, sporty trim package, and extended cab -- available on the base 1997 Ford F-150 truck. The results show that the respondents' stated WTP reflected the value of the options as determined from their prices and fraction of sales.

Monroe, E. M., Cook, H. E.

FE Analysis, Dynamic Test and Correlation of Vehicle Structures

96256810/01/1996

Computer simulation using finite element analysis techniques was used to predict and improve the performance of vehicle components and structures. In order to determine the actual loading and validate the FE model, extensive physical testing which involved data acquisition and analysis was undertaken. The paper shows the application of FE analysis and testing with examples for optimization of an automotive wheel, drive line vibration, car body shell interior acoustics and a railway vehicle structure.

Rao, Ananda, Srinivasulu, B., Bidanov, Alex, Currie, Andrew

Super Olefin Polymer for Material Consolidation of Automotive Interior Plastic Parts

96029602/01/1996

A new automotive interior component material, TSOP-5 has been developed by refining the technology utilized to develop TSOP-1, the high modulus and high flow material for bumper covers. This new interior component material has excellent molding capability (MI=30dg/min.) yet still maintains high impact resistance which enables the material to be used in areas such as the dash board as well as trim covers requiring to meet the FMVSS 214, the new side impact regulation or the FMVSS 201, the new soft upper trim regulation.

Kawamura, Nobuya, Nomura, Takao, Nishio, Takeyoshi

Ford Explorer Control Trac 4x4 System

95264511/01/1995

PURPOSE - Present the new Control Trac four wheel drive system which is the first application of an interactive four wheel drive in a sport utility vehicle. PROBLEM - The Control Trac system was developed in response to the need for a light weight, space efficient, customer friendly, and full function four wheel drive system. The system was targeted to be fully compatible with on highway and off road usage. CONCLUSION - The Control Trac system is a remarkably user friendly, practical, technologically advanced four wheel drive system; compatible with on highway and off road operation.

McKenzie, Clive A., Rama, Gordon P., Martins, Richard A.

Lateral Displacement Joint

94073403/01/1994

Development is being undertaken of a new type of flexible drive providing lateral displacement between rotating shafts in an axial length no greater than the lateral displacement. These large displacements are undertaken whilst maintaining full torque, constant velocity and with dynamic stability. Minimal forces are reacted on external bearings. Description is given of the mechanical design and automotive implementation together with an outline of the driving and dynamic loads within the unit during displacement. Application studies are described for incorporation of the unit into a range of vehicles including front wheel drive, four wheel drive, off highway and trucks.

Dowling, J., Allday, E. J.

The Design and Construction of MIRA's Climatic Wind Tunnel

93195711/01/1993

Due to customer demand, the features list of motor vehicles for the next century will require manufacturers to design vehicles that not only keep up with exacting legislation changes, but also meet higher specifications combined with reduced product cycle times. This paper outlines the development of MIRA's Climatic Wind Tunnel (CWT) as a commercially sponsored venture with total funding being generated within the Automobile Industry, and the effect that this sponsorship had on the fundamental design parameters. The facility can provide air temperatures from -40°C to +55°C, and humidity from 5% to 95% with wind and road speeds up to 200km/h. Both solar and hot road radiation can be simulated. It can accommodate both 2-wheel and 4-wheel drive vehicles and can absorb up to 300 kW of power at the road wheels. The construction of the £4.5 million CWT project was project managed by MIRA's own Civils and Facility Departments and took 14 months to complete from start to finish. This was a

Fletcher, D. W.

A Four Wheel Drive Transfer Case with Internal VR Motors for Shifting and Clutch Actuation

93305311/01/1993

A modular, fully automatic transfer case was designed and developed using electronically controlled inboard electric motors for shifting the high - low range and automatically shifting into four wheel drive for control of torque to the front axle. Compact modular construction was used to minimize weight, to provide for either reduction or overdrive, and for easy adaptation to different transmissions.

Baxter, Ralph W.

Vehicle Drawbar Test Characteristics of Electric and Viscous Clutch All Wheel Drive Systems

93305211/01/1993

Vehicle drawbar testing was conducted in order to establish the relative performance of all wheel drive electric and viscous clutch transfer case systems. The drawbar tests of a Ford Aerostar system with an electric clutch transfer case are compared to viscous clutch systems in a GM Astro and a Chrysler Grand Cherokee. The empirical test results and theoretical comparison show that the electric clutch transfer case system has a greater amount of torque transfer and its reaction time is faster.

Goddard, Steve

Performance of Dyna-Bite Traction System

93239009/01/1993

The Dyna-Bite®* traction system, developed by the Omitrac corporation, consists of a series of retractable spades which can be placed over a conventional tractor drive tires to improve traction under varying soil conditions. An initial model of the traction system was tested in 1986 (1)**. The performance of this model was compared with a 2WD tractor equipped with single drive tires and a front wheel assist (FWA) tractor. More recently, an improved model DB3-RM was evaluated at the University of Saskatchewan. The results were compared with an equally ballasted IH 1086 2WD tractor equipped with single and dual drive wheels (2). Tests for both studies were conducted on a wide range of soil moisture conditions under a variety of drawbar pull levels. Both models of the traction system provided significant traction improvements. Initial model of the traction system performed nearly as good as FWA while the later model proved superior to both single and dual wheels.

Wilson, Cameron A., Kushwaha, R. L.

Collision Speed Estimation Using a Single Normalised Crush Depth-Impact Speed Characteristic

92060402/01/1992

Theoretical consideration of the energy absorption properties of structures shows that the specific energy absorption (E/Mk) is related to the normalised crush depth (d/L) and to a stress/density parameter. Examination of the crush characteristics of the car population shows that the mean stress/density parameter of the car population in frontal crush is independent of car size. On this basis regression is carried out which relates (2×E/Mk)½ to normalised crush depth (d/L)⅔ Using data from nine staged frontal car to car collisions this generalised specific energy absorption representation is compared with CRASH 3 and with Prasad's (5) individual car reformulation. It is shown that the accuracy of Delta V prediction with Prasad's individual car reformulation is superior to both the normalised crush depth model proposed here and to CRASH 3, both of which have similar accuracies. A missing vehicle energy estimator, E1×[1+Mk1/Mk2] is examined as is the crush depth energy estimator, E1×[1

Wood, Denis P.

Design of Curved Solar Arrays for Solar-Powered Electric Vehicles

91163608/01/1991

Students at Rose-Hulman Institute of Technology have designed, fabricated and efficiently integrated a flat solar array in Rose-Hulman's Solar Phantom solar-powered electric vehicle. The choice of a fixed, flat array was influenced by the simplicity and the cost of manufacturing and the number and cost of photovoltaic cells rather than just the energy collecting ability of the array itself. There are three basic types of solar arrays used for solar-powered electric vehicles: curved arrays, flat arrays, and tracking arrays. Our objective is to present a comparison of the three array types based on the power and size constraints imposed by the solar-powered electric vehicle race rules. Although in selecting the type of array for a solar-powered electric vehicle there are concerns other than the energy collecting capability, such as the vehicle aerodynamics, we consider the type of study we have conducted as a necessary first step in understanding the trade-offs with different array

Lebaric, Jovan E., Manche, Alan A.

Encoders, Switches and Other Electronic Components Utilizing New Thick Film Material Technology

910494

02/01/1991

A new thick film material system produces smooth long wearing conductor patterns surrounded by a non-abrasive insulating surface. The insulator/conductor interface is essentially co-planar which allows extremely long life with a sliding contact. Mechanical, electrical and environmental integrity are excellent due to use of high temperature cermet materials on the alumina ceramic substrates. Manufacturing costs are low due to the process simplicity. Several automotive electronic components utilizing this technology are described.

Riley, Richard E., Sparks, Daniel R.

Modular, Electronic Traction Control Transfer Case

91248501/01/1991

A modular traction control transfer case was designed and developed using two variable reluctance electronically controlled inboard electric motors to shift high/low range and operate traction control. The modular construction helps to minimize the weight of the transfer case assembly, providing for the adaptation of reduction or over-drive ratios with minimal modification. The module design also provide easy adaptation to numerous transmission and because of its unique design the transfer case lends itself to low clearance floor pans. The compact size of the transfer case is a prime example of the “power density” concept; it is light weight and compact. Even with two electric motors internal to the design, space is utillized to the fullest. The transfer case offers a full array of functions consisting of: high gear 2 wheel drive with the front axle disconnected; part time 4 wheel drive with the front and rear axle rigidly connected; synchronized 2 wheel to 4 wheel drive with shifting

Reuter, Dave Carnell

Stages in the Development of Four-Wheel Drive Systems in Audi Passenger Cars

910020

01/01/1991

In terms of vehicle dynamics, four-wheel drive exhibits great capabilities as a power transmission system for high-performance passenger cars. There are now numerous different concepts for four-wheel drive configurations. To provide an overview of the different systems and their characteristics, this report first defines the design requirements for four-wheel drive systems. It then compares the alternative concepts in schematic form. Finally, the results of simulations and measurements are given to describe the characteristics of the quattro system developed by Audi in the various stages of its development.

Hessing, Bernd, Muller, Ernst, Stockmar, Jurgen