Document ID: chunk:federal_register_of_legislation:F2014C01109:body:0:p28
Version: federal_register_of_legislation:F2014C01109
Segment Type: other
Provision Reference: 
Character Range: 83288–86484

computer controlled with the computer using a closed-loop algorithm to limit vehicle oversteer and to limit vehicle understeer based on the evaluation of actual vehicle behaviour in comparison with a determination of vehicle behaviour demanded by the driver;
0.5.                                    That has a means to determine directly the value of the vehicle's yaw rate and to estimate its side-slip or side-slip derivative with respect to time;
0.6.                                    That has a means to monitor driver steering inputs; an
0.7.                                    That has an algorithm to determine the need, and a means to modify propulsion torque, as necessary, to assist the driver in maintaining control of the vehicle.
0.8.                                    "Lateral acceleration" means the component of the acceleration vector of a point in the vehicle perpendicular to the vehicle x axis (longitudinal) and parallel to the road plane.
0.9.                                    "Oversteer" means a condition in which the vehicle's yaw rate is greater than the yaw rate that would occur at the vehicle's speed as a result of the Ackerman steer angle.
0.10.                                "Side-slip or side-slip angle" means the arctangent of the ratio of the lateral velocity to the longitudinal velocity of the centre of gravity of the vehicle.
0.11.                                "Understeer" means a condition in which the vehicle's yaw rate is less than the yaw rate that would occur at the vehicle's speed as a result of the Ackerman steer angle.
0.12.                                "Yaw rate" means the rate of change of the vehicle's heading angle measured in degrees/second of rotation about a vertical axis through the vehicle's centre of gravity.
0.13.                                "Peak braking coefficient (PBC)": means the measure of tyre to road surface friction based on the maximum deceleration of a rolling tyre.
0.14.                                "Common space" means an area on which more than one tell-tale, indicator, identification symbol, or other message may be displayed but not simultaneously.
0.15.                                "Static stability factor" means one-half the track width of a vehicle divided by the height of its center of gravity, also expressed as SSF = T/2H, where: T = track width (for vehicles with more than one track width the average is used; for axles with dual wheels, the outer wheels are used when calculating "T") and H = height of the center of gravity of the vehicle.
          1. GENERAL Requirements

1.1.                                    Every ESC system must comply with the definition of paragraph 0.2 of this appendix and shall meet the equipment, performance and test requirements contained in this appendix.

1.2.                                    Vehicles equipped with an ESC system shall meet the functional requirements specified in paragraph 2. and the performance requirements in paragraph 3. under the test procedures specified in paragraph 4. and under the test conditions specified in paragraph 5. of this appendix.

       2. FUNCTIONAL REQUIREMENTS

        Each vehicle to which this