Directive 2005/55/EC of the European Parliament and of the Council (repealed)Show full title

2. GENERATION OF THE REFERENCE TEST CYCLE

The transient test cycle is described in Appendix 3 to this Annex. The normalised values for torque and speed shall be changed to the actual values, as follows, resulting in the reference cycle.

2.1. Actual speed

The speed shall be unnormalised using the following equation:

The reference speed (n_ref) corresponds to the 100 % speed values specified in the engine dynamometer schedule of Appendix 3. It is defined as follows (see Figure 1 of Annex I):

where n_hi and n_lo are either specified according to Annex I, Section 2 or determined according to Annex III, Appendix 1, Section 1.1.

2.2. Actual torque

The torque is normalised to the maximum torque at the respective speed. The torque values of the reference cycle shall be unnormalised, using the mapping curve determined according to Section 1.3, as follows:

Actual torque = (% torque × max. torque/100)

for the respective actual speed as determined in Section 2.1.

The negative torque values of the motoring points (‘m’) shall take on, for purposes of reference cycle generation, unnormalised values determined in either of the following ways:

• negative 40 % of the positive torque available at the associated speed point,

• mapping of the negative torque required to motor the engine from minimum to maximum mapping speed,

• determination of the negative torque required to motor the engine at idle and reference speeds and linear interpolation between these two points.

2.3. Example of the unnormalisation procedure

As an example, the following test point shall be unnormalised:

% speed

=

43

% torque

=

82

Given the following values:

reference speed

=

2 200 min^-1

idle speed

=

600 min^-1

results in,

actual speed = (43 × (2 200 - 600)/100) + 600 = 1 288 min^-1

actual torque = (82 × 700/100) = 574 Nm

where the maximum torque observed from the mapping curve at 1 288 min^-1 is 700 Nm.