Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p17
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 17/30)
Character Range: 566699–570194

positive portion shall be included in the integrated value.

Wact shall be between – 15 % and + 5 % of Wref

        3.9.3. Validation statistics of the test cycle

              Linear regressions of the feedback values on the reference values shall be performed for speed, torque and power. This shall be done after any feedback data shift has occurred, if this option is selected. The method of least squares shall be used, with the best fit equation having the form:

y = mx + b

         where:

         y = Feedback (actual) value of speed (min-1), torque (Nm), or power (kW)

         m = slope of the regression line

         x = reference value of speed (min-1), torque (Nm), or power (kW)

         b = y intercept of the regression line

              The standard error of estimate (SE) of y on x and the coefficient of determination (r2) shall be calculated for each regression line.

              It is recommended that this analysis be performed at 1 Hertz. All negative reference torque values and the associated feedback values shall be deleted from the calculation of cycle torque and power validation statistics. For a test to be considered valid, the criteria of table 7 must be met.

Table 7

Regression line tolerances

                                            Speed             Torque                                                  Power
Standard error of estimate (SE) of Y on X   Max 100 min–1     Max 13 % (15 %) (*) of power map maximum engine torque  Max 8 % (15 %) (*) of power map maximum engine power
Slope of the regression line, m             0,95 to 1,03      0,83–1,03                                               0,89–1,03

                                                                                                                      (0,83–1,03) (*)
Coefficient of determination, r2            min 0,9700        min 0,8800                                              min 0,9100

                                            (min 0,9500) (*)  (min 0,7500) (*)                                        (min 0,7500) (*)
Y intercept of the regression line, b       ± 50 min–1        ± 20 Nm or ± 2 % (± 20 Nm                               ± 4 kW or ± 2 % (± 4 kW or
                                                              or ± 3 %) (*) of max torque whichever is greater        ± 3 %) (*) of max power which- ever is greater

         (*) Until 1 October 2005, the figures shown in brackets may be used for the type-approval testing of gas engines. (The Commission shall report on the development of gas engine technology to confirm or modify the regression line tolerances applicable to gas engines given in this table.)

              Point deletions from the regression analyses are permitted where noted in Table 8.

Table 8

Permitted point deletions from regression analysis

Conditions                                                                                                                            Points to be deleted
Full load demand and torque feedback < 95 % torque reference                                                                          Torque and/or power
Full load demand and speed feedback < 95 % speed reference                                                                            Speed and/or power
No load, not an idle point, and torque feedback > torque reference                                                                    Torque and/or power
No load, speed feedback ≤ idle speed +