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Standard

Electric Drivetrain Fluids (EDF)

2019-04-24
WIP
J3200
This SAE Information Report is to assist those concerned with lubricants used in drivetrain components powered by electric powerplants. The information contained herein will be helpful in understanding the terms related to the properties of a lubricant used in electric drivetrains.
Standard

Wheels - Radial Impact Test Procedure - Road Vehicles

2019-05-22
WIP
J3203
The SAE recommended practice provides a uniform laboratory test procedure for evaluating radial(road hazard) impact collision resistance of all wheels intended for use on passenger vehicles and light trucks.
Technical Paper

A Driving Simulator Using Microprocessors

1988-03-01
871156
An inexpensive driving simulation system with sufficient fidelity has been developed. The system produces motion cues of four degrees of freedom, visual and auditory cues, and control feel on the steering wheel. This paper describes the features of this newly developed system and gives examples that demonstrate its effectiveness. The motion cues provided in this system are yaw, heave, and lateral and fore/aft accelerations. The lateral and fore/aft accelerations are simulated by tilting the simulator compartment. A computer-processed road image is given through a CRT monitor. The restoring torque of the steering wheel is produced by an electrical servosystem via a coil spring. Cruising sound is given in order to improve speed perception. Since the system uses digital computers, the vehicle characteristics are altered easily by merely rewriting the software. This enables us to simulate special vehicle dynamics such as front & rear wheel steering.
Technical Paper

A Study on the Performance of Guideway Bus Steering Control System

1988-03-01
871231
In this paper a computer simulation study on the effects of steering parameters on lateral dynamics of the guideway bus to contribute to a development practice of designing optimum steering control system are dealt with. A stability limit of vehicle lateral motion is analyzed and an emphasis is laid on the effects of moment of inertia of a conventional steering wheel and lateral elasticity of the guide rail which have proven to reduce the critical vehicle speed. It is pointed out conclusively that a normal bus equipped with additional simple guidance equipments can be guided smoothly on a simple guideway at adequately high vehicle speed.
Standard

Definition and Measurement of Beam Axle Efficiency

2019-12-04
WIP
J3218
This SAE Recommended Practice covers beam axles used in passenger car and light-duty truck applications. Beam Axles utilize differentials which are of the open, limited slip, locking or spool types, although other configurations are possible
Technical Paper

Fundamental Physics Behind New Suspension Concept for Automobiles

2000-05-01
2000-01-1647
The Transverse Leaf suspension with Superior Roll Axis is a new suspension concept for automobiles. It enables the load transfer during a turn to be more evenly redistributed between the two wheels on the same axle thus optimizing its tires lateral force capabilities. The TLSRA concept is made up of a single transverse leaf spring linking the middle of the sprung mass to the outer end of 2 transverse suspension arms per axle. Those transverse arms are mounted close to the middle of the sprung mass with their attachment points located above the mass centroïd. Each wheel assembly is mounted directly onto the free end of its respective suspension arm. Because body roll is now counteracting vertical load transfer during transient and permanent operating conditions, this suspension enables designers to keep spring stiffness low without compromising road handling.
Technical Paper

Development of Active-Traction Control System

2000-05-01
2000-01-1636
Active-TRAC (A-TRAC) is the system for off-road 4WD vehicles. This system consists of independent four wheel brake control system and engine torque control system. This system applies the brake to any spinning wheel, and sends torque to the other wheels with grip. Therefore, the vehicle gets strong LSD(Limited Slip Differential) effect, and it has the same traction performance as a center and rear differential locked vehicle. Because the vehicle with A-TRAC does not have a differential locking mechanism, it no longer has the phenomenon of tight corner braking, and it frees a driver from operating the differential locking system. Therefore anyone can easily enjoy off-road driving with A-TRAC.
Technical Paper

An Automatic Vehicle Controller for Stability and Handling Tests

2000-05-01
2000-01-1627
An automatic vehicle controller (AVC) which was specified, designed, fabricated, installed and used on a variety of vehicles, including automobiles, light trucks, and sport utility vehicles is described. The AVC controls the vehicle's steering, and input waveforms of virtually any type or complexity can be specified from computer files containing steering wheel angle commands as functions of time. Also, algorithms which use motion sensor feedback in the steering control logic can be programmed. Throttle and brake controls can also be provided.
Technical Paper

Improving the Ride & Handling Qualities of a Passenger Car via Modification of its Rear Suspension Mechanism

2000-05-01
2000-01-1630
This paper presents the results of a recent project of IKCo’s research center to modify the Paykan 1600’s rear suspension mechanism with the purpose of improving the car’s comfort, stability and handling qualities. The car was originally equipped with a solid rear axle with leaf springs. By replacing the original mechanism with a three-link mechanism with panhard bar and coil springs, the ride comfort and handling characteristics of the car were noticeably improved.3-D, nonlinear ride and handling models were developed and analyzed to determine the important kinematics and dynamic effects of the new mechanism on vehicle responses. To verify the analytical results, subjective tests were carried out on the vehicle. The results of these tests demonstrated remarkable improvement of the dynamics behavior of the car.
Technical Paper

Elimination of Roll, Squat, and Dive Through Biased Suspension Response

2000-05-01
2000-01-1632
Conventionally sprung vehicles are subject to rolling and pitching of the sprung load as the vehicle corners and accelerates, respectively. Designs which incorporate active elements seek to control these movements, frequently resulting in compromised performance or reduced fuel economy. This paper considers the possible replacement of conventional springs, shocks, and anti-sway bars with specified fluid spring components. The fluid spring components offer biased response to dynamic load variations in the following manner: provide support of the sprung load equal to the magnitude of the load at each moment, and either compressing readily to absorb upward forces originating in the wheel assembly which exceed the magnitude of the load at that moment, or extending rapidly to provide support equal to the magnitude of the load at that moment, in the event the wheel assembly tracks through a hole.
Technical Paper

Dynamics Simulation Research on Rigid-Elastic Coupling System of Car Suspension

2000-05-01
2000-01-1622
In modern car, to reduce car deadweight, lightweight technology is widely used; and to improve comfortable and handling performance, many rubber bushings installed between car body and suspension. These parts have difference characteristics during car running at high speed comparing these at static state. Accounting the suspension performance has a decisive influence on a car, the flexible parts should be taken into account in the suspension/steering system simulation model. As a deviant phenomenon, the steering wheel shimmy affects the suspension's dynamic characteristics greatly. To analysis this abnormal running state, the front wheel bounce tracks were figured out by using different front suspension model. The flexible parts installed in suspension are idealized respectively as rigid poles, flexible beams or forces, hence, the rigid suspension analytical model and the rigid-elastic suspension model analytical were built respectively.
Technical Paper

Investigation of Package Bearings to Improve Driveline Performance

2000-06-19
2000-01-1785
The tapered roller bearings employed in axle centers for the pinion support are critical components in determining the noise, fuel economy and reliability characteristics of the vehicle. They represent a relatively complex mechanical and tribological system, with special requirements from the stiffness, lubrication and heat transfer points of view. This paper brings a contribution to the investigation of the intricate dependency between design parameters, environmental factors and the resultant performance of a package bearing in an integral double cup configuration. Axial compactness, reduced weight, and superior rigidity are only few of the multiple advantages recommending this type of double row bearings for automotive driveline applications. Different aspects related to the tapered roller bearing setting are analyzed in a theoretical and experimental manner, also under the consideration of the manufacturing and assembly processes.
Technical Paper

NEWPED - A Stealth Auxiliary Engine in a Bicycle with Very Low Noise, Low Pollutant Emission and Good Fuel Economy

1999-09-28
1999-01-3280
The development history of a 30cc 2-stroke engine power unit in the covered rear wheel for retrofit into standard bicycle chassis. The rear wheel acts as cooling fan for the air cooled long stroke engine with catalyst exhaust system, autochoke carburetor, autolube oil pump, electric start and inertia start, single speed automatic transmission and 7 speed hub final drive. The space in the rear wheel contains intake air filter, exhaust system, fuel tank, oil tank and engine with drive train, the complete engine being only 94mm wide. The complete covered power unit is nearly undetectable as the rear wheel covers resemble road racing bicycles. There is very low stationary and pass-by noise (64 db[A]), no exhaust gas opacity or smell, very low vibration level and very good fuel economy up to 133 km/l.
Technical Paper

Analysis of Automotive Handling Based on Tire Cornering Properties in Non-Steady State Conditions

1999-11-15
1999-01-3758
Non-steady state (NSS) tire cornering properties show obvious differences from steady state (SS) tire cornering properties. A two-DOF automobile model with steer angle as an input is established based on the known NSS tire model considering complex carcass deformation. The tire model can certainly be applied to modelling of a multi-DOF automobile system. The frequency responses of lateral acceleration and yaw rate are then derived. An evaluation index, amplitude-frequency characteristic of relative error (AFCRE), is used to analyze the influences of NSS front wheels (FW) and/or rear wheels (RW) on automotive handling. The influences of NSS FW are much greater than those of NSS RW only on automotive handling. The established automobile model can also be applied to other similar studies of vehicle dynamics.
Technical Paper

Differential Torque Steering for Future Combat Vehicles

1999-11-15
1999-01-3740
This paper discusses the evolution of skid steer systems, and takes a new look at the advantages and implications of designing future ground combat vehicles with all non-steerable wheels. The traditional “skid steer” designation of such vehicles is dropped in favor of the more descriptive phrase “differential torque steer” vehicle. The possible advantages of such systems for combat vehicle application are presented along with a synopsis of various past modeling, simulation, and vehicle hardware efforts to evaluate skid steer systems. A comprehensive vehicle modeling effort for a differential torque steer system is then presented. Two independent implementations of the model are presented along with model verification and validation results. Finally the model is used to evaluate potential turning performance for a 4×4 vehicle with differential torque steer.
Technical Paper

New Traction-Optimized Front Axle Limited-Slip Differential for AWD All-Terrain-Vehicle

2000-03-06
2000-01-1155
An advancement in All-Terrain-Vehicle (ATV) traction control has entered the market place with the debut of the 1999 Bombardier Traxter. The basis for this is the progressive front axle limited-slip differential. The Visco Lok‚ differential provides a speed-sensing progressive traction-optimized characteristic for maximum off-road performance. This paper includes an overview of the vehicle driveline system, functional characteristics of the differential, and torque transfer requirements.
Technical Paper

A New EPS Control Strategy to Improve Steering Wheel Returnability

2000-03-06
2000-01-0815
This paper proposes a new Electric Power Steering (EPS) control strategy that enables improvement to steering-wheel returnability. Using a conventional EPS controller, frictional loss torque in the steering mechanism reduces steering-wheel returnability, which drivers occasionally perceive as unpleasant. This phenomena occurs in any EPS system regardless of motor type or mounting location. To improve steering-wheel returnability for EPS-equipped vehicles, we developed a new control strategy based on estimation of alignment torque generated by tires and road surfaces. This proposed control strategy requires no supplemental sensors like steering-wheel angle or motor-angle sensors. We experimented with this proposed control algorithm using a test vehicle and confirmed that it enables improved steering wheel returnability and also better on-center feeling.
Technical Paper

Presentation of Flow Field Investigation by PIV on a Full-Scale Car in the Pininfarina Wind Tunnel

2000-03-06
2000-01-0870
Particle Image Velocimetry (PIV) is a recent measuring technique, which has been used up to now mainly by University Laboratories in small-scale wind tunnels and by Aeronautical Research Centers in small and large facilities. Its use in full-scale automotive testing is not common. It is not so easy, often rather difficult, due to a number of problems, sometimes of practical nature, sometime caused by technology limitations. This paper reports the results of some tests, carried out by CIRA (Centro Italiano Ricerche Aerospaziali) in the Pininfarina wind tunnel on a full-scale car, in the frame of the European Thematic Network “PIVNET”. A description of the test set up, of the instrumentation used for these tests, as well as an analysis of the advantages provided by this technique and of its present limitations, are reported. During the tests, in order to outline the potential of this measuring technique, some specific areas of the car flow field, have been investigated.
Technical Paper

Rheological Properties Affecting the Fuel Economy of Multigrade Automotive Gear Lubricants

2000-06-19
2000-01-2051
The paper highlights the use of a light duty axle efficiency test for evaluating the fuel economy performance of automotive gear lubricants. Both final peak axle temperatures and torque efficiencies are recorded for several multigrade automotive gear lubricants. The dependence of temperature on torque efficiencies for the gear lubricants tested are discussed for a variety of driving conditions: city, highway and severe service. Temperature and torque efficiency data show strong dependence on additive system and viscosity- temperature characteristics of the gear lubricants under different driving conditions. A discussion of lubricant rheology and its importance to maintaining film strength for adequate bearing and gear lubrication as related to optimum torque efficiency and axle temperature under varying loads and pinion speeds is also provided.
Technical Paper

Air Bag Parameter Study with Out-Of-Position Small Female Test Devices

2000-06-19
2000-01-2204
The development of the Advanced Restraint System has lead to an innovative way in which we evaluate the systems effect on the occupant. This paper presents some initial investigation into the driver airbag system that consists of an inflator, cushion fold, tear seam pattern, and offset of the airbag cover to steering wheel rim plane. An initial DOE is reviewed to establish significant parameters and to identify equations for further investigation.
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