Document ID: chunk:federal_register_of_legislation:F2021C00477:body:0:p74
Version: federal_register_of_legislation:F2021C00477
Segment Type: other
Provision Reference: 
Character Range: 193544–196135

may be, in addition to the driver, a second person on the front seat who is responsible for noting the results of the tests.
2.3.2 Braking tests shall be carried out on a dry surface affording good adhesion.
2.4. Test method
2.4.1. The tests as described in paragraphs 3. and 4. of this section shall be carried out from a test speed of 100 ± 2 km/h. The vehicle shall be driven at the test speed in a straight line.
2.4.2. The average temperature of the brakes shall be in accordance with paragraph 1.4.1.1. of Annex 3.
2.4.3. For the tests the reference time, t0, is defined as the moment when the brake pedal force reaches 20 N.
 Note: For vehicles equipped with a brake system assisted by an energy source, the applied pedal force necessary depends on the energy level that exists in the energy storage device. Therefore, sufficient energy level shall be ensured at the beginning of the test.
3. Assessment of the presence of a category "A" BAS
 A category "A" BAS shall meet the test requirements contained in paragraphs 3.1. and 3.2.
3.1. Test 1: Reference test to determine FABS and aABS.
3.1.1. The reference values FABS and aABS shall be determined in accordance with the procedure described in Appendix 4 to this annex.
3.2. Test 2: For activation of BAS
3.2.1. Once an emergency braking condition has been detected, systems sensitive to pedal force shall show a significant increase in the ratio of:
(a) Brake line pressure to brake pedal force, where permitted by paragraph 3.2.5.; or
(b) Vehicle deceleration to brake pedal force.
3.2.2. The performance requirements for a category "A" BAS are met if a specific brake application characteristic can be defined that exhibits a decrease of between 40 per cent and 80 per cent in required brake pedal force for (FABS - FT) compared to (FABS extrapolated - FT).
3.2.3. FT and aT are threshold force and threshold deceleration as shown in Figure 1. The values of FT and aT shall be supplied to the Technical Service at the time of submission of the type-approval application. The value of aT shall be between 3.5 m/s² and 5.0 m/s².

       Figure 1a
       Pedal force characteristic needed in order to achieve maximum deceleration with category "A" BAS

3.2.4. A straight line is drawn from the origin through the point FT, aT (as shown in Figure 1a). The value of brake pedal force "F", at the point of intersection between this line and a horizontal line defined by a=aABS, is defined
as FABS, extrapolated:
3.2.5. As an alternative, which can be selected by the manufacturer, in the case of vehicles of category N1, or M1 derived