Commission Delegated Regulation (EU) No 134/2014Show full title

Appendix 7 Road tests of L-category vehicles equipped with one wheel on the driven axle or with twinned wheels for the determination of test bench settings

1. Requirements for the rider

1.1. The rider shall wear a well-fitting (one-piece) suit or similar clothing and a protective helmet, eye protection, boots and gloves.

1.2. The rider, dressed and equipped as described in point 1.1., shall have a mass of 75 kg ± 5 kg and be 1,75 m ± 0,05 m tall.

1.3. The rider shall be seated on the seat provided, with his feet on the footrests and his arms extended normally. This position shall allow the rider to have proper control of the vehicle at all times during the tests.

2. Requirement for the road and ambient conditions

2.1. The test road shall be flat, level, straight and smoothly paved. The road surface shall be dry and free of obstacles or wind barriers that might impede the measurement of the running resistance. The slope of the surface shall not exceed 0,5 percent between any two points at least 2 m apart.

2.2. During data collecting periods, the wind shall be steady. The wind speed and the direction of the wind shall be measured continuously or with adequate frequency at a location where the wind force during coast-down is representative.

2.3. The ambient conditions shall be within the following limits:

• maximum wind speed: 3 m/s

• maximum wind speed for gusts: 5 m/s

• average wind speed, parallel: 3 m/s

• average wind speed, perpendicular: 2 m/s

• maximum relative humidity: 95 percent

• air temperature: 278,2 K to 308,2 K

2.4. Standard ambient conditions shall be as follows:

• pressure, P₀: 100 kPa

• temperature, T₀: 293,2 K

• relative air density, d₀: 0,9197

• air volumetric mass, ρ₀: 1,189 kg/m³

2.5. The relative air density when the vehicle is tested, calculated in accordance with the formula Ap 7-1, shall not differ by more than 7,5 percent from the air density under the standard conditions.

2.6. The relative air density, d_T, shall be calculated using the following formula:

Equation Ap 7-1:

where:

• d₀ is the reference relative air density at reference conditions (1,189 kg/m³)

• p_T is the mean ambient pressure during the test, in kPa;

• p₀ is the reference ambient pressure (101,3 kPa);

• T_T is the mean ambient temperature during test, in K;

• T₀ is the reference ambient temperature (293,2 K).

3. Condition of the test vehicle

3.1. The test vehicle shall comply with the conditions described in point 1 of Appendix 8.

3.2. When installing the measuring instruments on the test vehicle, care shall be taken to minimise their effects on the distribution of the load across the wheels. When installing the speed sensor outside the vehicle, care shall be taken to minimise the additional aerodynamic loss.

3.3. Checks

The following checks shall be made in accordance with the manufacturer’s specifications for the use considered: wheels, wheel rims, tyres (make, type and pressure), front axle geometry, brake adjustment (elimination of parasitic drag), lubrication of front and rear axles, adjustment of the suspension and vehicle ground clearance, etc. Check that during freewheeling, there is no electrical braking.

4. Specified coast-down speeds

4.1. The coast-down times must be measured between v₁ and v₂ as specified in Table Ap 7-1, depending on the vehicle class as defined in point 4.3. of Annex II.

4.2.

Table Ap7-1

Coast-down time measurement beginning speed and ending speed

Maximum design speed (km/h)	Specified target vehicle speedvj in (km/h)	v1 in (km/h)	v2 in (km/h)
≤ 25 km/h
	20	25	15
	15	20	10
	10	15	5
≤ 45 km/h
	40	45	35
	30	35	25
	20	25	15
45 < maximum design speed ≤ 130 km/h and > 130 km/h
	120	130*/	110
	100	110*/	90
	80	90*/	70
	60	70	50
	40	45	35
	20	25	15

4.3. When the running resistance is verified in accordance with point 5.2.2.3.2., the test can be executed at vj ± 5 km/h, provided that the coast-down time accuracy referred to in point 4.5.7. of Annex II is ensured.

5. Measurement of coast-down time

5.1. After a warm-up period, the vehicle shall be accelerated to the coast-down starting speed, at which point the coast-down measurement procedure shall be started.

5.2. Since shifting the transmission to neutral can be dangerous and complicated by the construction of the vehicle, the coasting may be performed solely with the clutch disengaged. Vehicles that have no means of cutting the transmitted engine power off prior to coasting may be towed until they reach the coast-down starting speed. When the coast-down test is reproduced on the chassis dynamometer, the drive train and clutch shall be in the same condition as during the road test.

5.3. The vehicle steering shall be altered as little as possible and the brakes shall not be operated until the end of the coast-down measurement period.

5.4. The first coast-down time Δt_ai corresponding to the specified speed v_j shall be measured as the time taken for the vehicle to decelerate from v_j + Δv to v_j – Δv.

5.5. The procedure described in points 5.1. to 5.4. shall be repeated in the opposite direction to measure the second coast-down time Δt_bi.

5.6. The average Δt_i of the two coast-down times Δt_ai and vt_bi shall be calculated using the following equation:

Equation Ap 7-2:

5.7. At least four tests shall be performed and the average coast-down time ΔTj calculated using the following equation:

Equation Ap 7-3:

5.8. Tests shall be performed until the statistical accuracy P is equal to or less than 3 percent (P ≤ 3 percent).

The statistical accuracy P (as a percentage) is calculated using the following equation:

• Equation Ap7-4:

  

  where:

  • t is the coefficient given in Table Ap 7-2;

  • s is the standard deviation given by the following formula:

• Equation Ap7-5:

  

  where:

  n is the number of tests.

  Table Ap7-2
  Coefficients for statistical accuracy
  n	t
  4	3,2	1,6
  5	2,8	1,25
  6	2,6	1,06
  7	2,5	0,94
  8	2,4	0,85
  9	2,3	0,77
  10	2,3	0,73
  11	2,2	0,66
  12	2,2	0,64
  13	2,2	0,61
  14	2,2	0,59
  15	2,2	0,57

5.9. In repeating the test, care shall be taken to start the coast-down after observing the same warm-up procedure and at the same coast-down starting speed.

5.10. The coast-down times for multiple specified speeds may be measured in a continuous coast-down. In this case, the coast-down shall be repeated after observing the same warm-up procedure and at the same coast-down starting speed.

5.11. The coast-down time shall be recorded. A specimen record form is given in the Regulation for administrative requirements.

6. Data processing

6.1. Calculation of running resistance force

6.1.1. The running resistance force F_j, in Newton, at the specified speed v_j shall be calculated using the following equation:

Equation Ap7-6:

where:

m_ref

=

reference mass (kg);

Δv

=

vehicle speed deviation (km/h);

Δt

=

calculated coast down time difference (s);

6.1.2. The running resistance force F_j shall be corrected in accordance with point 6.2.

6.2. Running resistance curve fitting

The running resistance force, F, shall be calculated as follows:

6.2.1. The following equation shall be fitted to the data set of F_j and v_j obtained in points 4 and 6.1. respectively by linear regression to determine the coefficients f₀ and f₂,

Equation Ap7-7:

6.2.2. The coefficients f₀ and f₂ thus determined shall be corrected to the standard ambient conditions using the following equations:

• Equation Ap7-8:

  

• Equation Ap7-9:

  

  where:

  K₀ shall be determined on the basis of the empirical data for the particular vehicle and tyre tests or shall be assumed as follows, if the information is not available: .

6.3. Target running resistance force F* for chassis dynamometer setting

The target running resistance force F*(v₀) on the chassis dynamometer at the reference vehicle speed v₀, in Newton, is determined using the following equation:

Equation Ap7-10: