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The purpose of this SAE Information Report is to describe currently known automotive active stability enhancement systems, as well as identify common names which can be used to refer to the various systems and common features and functions of the various systems. The primary systems discussed are: a ABS—Antilock Braking Systems b TCS—Traction Control Systems c AYC—Active Yaw Control Systems The document is technical in nature and attempts to remain neutral about specific manufacturer designs, and automobile producer features.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a high frequency response spindle when a rolling tire impacts a cleat. The cleat is configured either with its crest perpendicular, 90°, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides impact force and moment time histories essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a high frequency response spindle when a rolling tire impacts a cleat. The cleat is configured either with its crest perpendicular, 90°, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides impact force and moment time histories essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a spindle when a tire rolls over a rectangular obstacle, cleat, at very low speed. The cleat used in a particular test condition is configured with its crest either perpendicular, 90°, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides cleat envelopment force and moment and tire angular position histories as functions of distance traveled. These histories are essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a spindle when a tire rolls over a rectangular obstacle, cleat, at very low speed. The cleat used in a particular test condition is configured with its crest either perpendicular, 90°, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides cleat envelopment force and moment and tire angular position histories as functions of distance traveled. These histories are essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a spindle when a tire rolls over a rectangular obstacle, cleat, at very low speed. The cleat used in a particular test condition is configured with its crest either perpendicular, 90 degrees, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides cleat envelopment force and moment and tire angular position histories as functions of distance traveled. These histories are essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a spindle when a tire rolls over a rectangular obstacle, cleat, at very low speed. The cleat used in a particular test condition is configured with its crest either perpendicular, 90 degrees, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides cleat envelopment force and moment and tire angular position histories as functions of distance traveled. These histories are essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire.

The parameters measured according to this SAE Recommended Practice will generally be used in simulating directional control performance in the linear range. (The “linear range” is the steady-state lateral acceleration below which steering wheel angle can generally be considered to be linearly related to lateral acceleration.) But they may be used for certain other simulations (such as primary ride motions), vehicle and suspension characterization and comparison, suspension development and optimization, and processing of road test data. This document is intended to apply to passenger cars, light trucks, and on-highway recreational and commercial vehicles, both non-articulated and articulated. Measurement techniques are intended to apply to these vehicles, with alterations primarily in the scale of facilities required.

The parameters measured according to this SAE Recommended Practice will generally be used in simulating directional control performance in the linear range. (The “linear range” is the steady-state lateral acceleration below which steering wheel angle can generally be considered to be linearly related to lateral acceleration.) But they may be used for certain other simulations (such as primary ride motions), vehicle and suspension characterization and comparison, suspension development and optimization, and processing of road test data. This document is intended to apply to passenger cars, light trucks, and on-highway recreational and commercial vehicles, both non-articulated and articulated. Measurement techniques are intended to apply to these vehicles, with alterations primarily in the scale of facilities required.

This SAE Information Report presents the background and rationale for SAE J1574-1. The motor vehicle industry is working toward a more complete understanding of the factors affecting the motions of vehicles on the roadway, by using a variety of techniques that predict responses to road and operator inputs. The capability to predict responses is desirable so that vehicles can be designed for optimum safety and utility. In addition to the force and moment properties of the pneumatic tires, a number of vehicle and suspension parameters affect the response of the vehicle; these include weight, center-of-gravity location, moments of inertia, suspension ride and roll rates, suspension kinematic and compliance properties, and shock absorber characteristics. These parameters must be quantified in order to predict vehicle responses. Measurement of most of these parameters will be limited to determining their values in the linear range for use in directional control simulations.

This SAE Information Report presents the background and rationale for SAE J1574-1. The motor vehicle industry is working toward a more complete understanding of the factors affecting the motions of vehicles on the roadway, by using a variety of techniques that predict responses to road and operator inputs. The capability to predict responses is desirable so that vehicles can be designed for optimum safety and utility. In addition to the force and moment properties of the pneumatic tires, a number of vehicle and suspension parameters affect the response of the vehicle; these include weight, center-of-gravity location, moments of inertia, suspension ride and roll rates, suspension kinematic and compliance properties, and shock absorber characteristics. These parameters must be quantified in order to predict vehicle responses. Measurement of most of these parameters will be limited to determining their values in the linear range for use in directional control simulations.

This recommended practice defines methods for the measurement of periodic, random and transient whole-body vibration. It indicates the principal factors that combine to determine the degree to which a vibration exposure will cause discomfort. Informative appendices indicate the current state of knowledge and provide guidance on the possible effects of motion and vibration on discomfort. The frequency range considered is 0.5 Hz to 80 Hz. This recommended practice also defines the principles of preferred methods of mounting transducers for determining human exposure. This recommended practice is applicable to light passenger vehicles (e.g., passenger cars and light trucks). This recommended practice is applicable to motions transmitted to the human body as a whole through the buttocks, back and feet of a seated occupant, as well as through the hands of a driver.

This recommended practice defines methods for the measurement of periodic, random and transient whole-body vibration. It indicates the principal factors that combine to determine the degree to which a vibration exposure will cause discomfort. Informative appendices indicate the current state of knowledge and provide guidance on the possible effects of motion and vibration on discomfort. The frequency range considered is 0.5 Hz to 80 Hz. This recommended practice also defines the principles of preferred methods of mounting transducers for determining human exposure. This recommended practice is applicable to light passenger vehicles (e.g., passenger cars and light trucks). This recommended practice is applicable to motions transmitted to the human body as a whole through the buttocks, back and feet of a seated occupant, as well as through the hands of a driver.

This recommended practice defines methods for the measurement of periodic, random and transient whole-body vibration. It indicates the principal factors that combine to determine the degree to which a vibration exposure will cause discomfort. Informative appendices indicate the current state of knowledge and provide guidance on the possible effects of motion and vibration on discomfort. The frequency range considered is 0.5 Hz to 80 Hz. This recommended practice also defines the principles of preferred methods of mounting transducers for determining human exposure. This recommended practice is applicable to light passenger vehicles (e.g., passenger cars and light trucks). This recommended practice is applicable to motions transmitted to the human body as a whole through the buttocks, back and feet of a seated occupant, as well as through the hands of a driver.

This SAE Recommended Practice describes an evaluation procedure for validating tire models for use in road load simulations and assesses the relevant dynamic behavior of tires. The laboratory test utilized is a “cleat” test, where a rolling tire on a drum encounters a cleat and the resulting dynamic forces and moments are measured. This test is described in SAE J2730, “Dynamic Cleat Test with Perpendicular and Inclined Cleats”. The test is commonly used to identify tire model parameters. In this recommended practice, requirements for the measurement of the tire’s response are described along with data processing techniques and calculations used to quantitatively compare the tire model’s calculated response to the tire’s response measured on test. This recommended practice addresses both the tire model structure and its parameters.

This SAE Recommended Practice describes an evaluation procedure for validating tire models for use in road load simulations and assesses the relevant dynamic behavior of tires. The laboratory test utilized is a “cleat” test, where a rolling tire on a drum encounters a cleat and the resulting dynamic forces and moments are measured. This test is described in SAE J2730, “Dynamic Cleat Test with Perpendicular and Inclined Cleats”. The test is commonly used to identify tire model parameters. In this recommended practice, requirements for the measurement of the tire’s response are described along with data processing techniques and calculations used to quantitatively compare the tire model’s calculated response to the tire’s response measured on test. This recommended practice addresses both the tire model structure and its parameters.

This SAE Recommended Practice establishes consistent test procedures for determination of steady-state directional control properties for passenger cars and light trucks with single axles. These properties include the gradients with respect to lateral acceleration of steering wheel angle, understeer/ oversteer, sideslip, roll angle, and steering wheel torque; the gains with respect to steering wheel angle of yaw velocity, lateral acceleration, and sideslip; the characteristic speed or critical speed; and the total, steering, and tire compliances at the front and rear wheels.

This SAE Recommended Practice establishes consistent test procedures for determination of steady-state directional control properties for passenger cars and light trucks with two axles. These properties include the steering-wheel angle gradient, reference steer angle gradient, sideslip angle gradient, vehicle roll angle gradient, and steering-wheel torque gradient with respect to lateral acceleration. They also include the yaw velocity gain, lateral acceleration gain, and sideslip angle gain with respect to steering-wheel angle. Additionally, the characteristic or critical speed and the front and rear wheel steer compliances may be determined.

This SAE Recommended Practice establishes a rating scale for subjective evaluation of vehicle handling. The scale is applicable for the evaluation of specific vehicle handling properties in specific maneuvers on the proving grounds and highways. The validity of the evaluation is restricted to the individual handling disciplines defined by these maneuvers and to the particular combination of conditions of the vehicle (e.g., equipment, degree of maintenance) and of the environment (e.g., road, weather). This document is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.

This SAE Recommended Practice establishes a rating scale for subjective evaluation of vehicle ride and handling. The scale is applicable for the evaluation of specific vehicle ride and handling properties, for specified maneuvers, road characteristics and driving conditions, on proving ground and public roads. The validity of the evaluation is restricted to the individual ride and handling disciplines defined by these maneuvers and to the particular combination of conditions of the vehicle (e.g., equipment, degree of maintenance) and of the environment (e.g., road, weather). This rating scale may not be suitable for some applications, such as specific types of ride or handling qualities, driver populations and market segments, or for correlating with objective measures. Appendix A - Other Scales discusses rating scales that better suit such applications.