Document ID: chunk:federal_register_of_legislation:F2010C00150:front:0:p41
Version: federal_register_of_legislation:F2010C00150
Segment Type: other
Provision Reference: 
Character Range: 109967–112758

decimal places.

         1.1.7. Then, the test will be repeated for the other axle(s) as defined in paragraphs 1.1.1. to 1.1.6. above.

         1.1.8. For example, in the case of a two-axle rear-wheel drive vehicle, with the front axle (1) being braked, the coefficient of adhesion (k) is given by:

 The other symbols (P, h, E) are defined in annex 5 to this Regulation.

         1.1.9. One coefficient will be determined for the front axle kf and one for the rear axle kr

         1.2. Determination of the adhesion utilized (epsilon)

         1.2.1. The adhesion utilized (epsilon) is defined as the quotient of the maximum braking rate with the anti-lock system operative (zAL) and the coefficient of adhesion (kM) i.e.,

         1.2.2. From an initial vehicle speed of 55km/h, the maximum braking rate (zAL) shall be measured with full cycling of the anti-lock braking system and based on the average value of three tests, as in paragraph 1.1.3. of this appendix, using the time taken for the speed to reduce from 45km/h to 15km/h, according to the following formula:

         l.2.3. The coefficient of adhesion kM shall be determined by weighting with the dynamic axle loads.

where :

1.2.4. The value of epsilon shall be rounded to two decimal places.
         1.2.5. In the case of a vehicle equipped with an anti-lock system of categories 1 or 2, the value of zAL will be based on the whole vehicle, with the anti-lock system in operation, and the adhesion utilized (epsilon) is given by the same formula quoted in Paragraph 1.2.1. of this appendix.

         1.2.6. In the case of a vehicle equipped with an anti-lock system of category 3, the value of zAL will be measured on each axle which has at least one directly controlled wheel. For example, for a two-axle rear-wheel drive vehicle with an anti-lock system acting only on the rear axle, the adhesion utilized (epsilon) is given by:

          This calculation shall be made for each axle having at least one directly controlled wheel.

         1.3. If epsilon > 1.00, the measurements of coefficients of adhesion shall be repeated. A tolerance of 10% is accepted.

Annex 6 - Appendix 3

PERFORMANCE ON DIFFERING ADHESION SURFACES

    1.1. The prescribed braking rate referred to in paragraph 5.3.5. of this annex may be calculated by reference to the measured coefficient of adhesion of the two surfaces on which this test is carried out. These two surfaces must satisfy the conditions prescribed in paragraph 5.3.4. of this annex.

    1.2. The coefficient of adhesion (kH  and kL) of the high-  and low-adhesion  surfaces, respectively, shall be determined in accordance with the provisions in paragraph 1.1. of appendix 2 to this annex.

1.3. The braking rate (zMALS) for laden vehicles shall be:

Annex