A test method of ISO R362, internationally most recommended test
standard, become serious problem for the regulation of
vehicle's exterior noise in Japan. Accordingly, it is
fundamentally important to research on the test errors caused by
miscellaneous factors.
This paper deals with error analysis regarding two of the main
factors of errors in the test of ISO R362, meter-reading error and
driver's operating error. For the former case, the data
population obtained by reading the sound pressure level meters is
compared with the population obtained from the data instrumentally
computed, and the statistical method of significance test is
applied for the observation in detail. As the result, there is no
evident significance between both populations, and the population
of computed data, however, has rather great deviation in
general.
For the later case, the several factors of errors resulted from
the driver's operating behavior are observed through the method
of multiple regression procedure. Four kinds of vehicles, a
passenger car, a light truck, a middle truck and a heavy truck, are
offered in the test. Analysis shows that the three kinds of errors,
the deviation of cruising speed before acceleration, the deviation
of acceleration point and the deviation from center line, will
introduce the significant effect on the total error in the test of
ISO R362