Patent EP-1048943-A2 (EP)
Inventor: NAKANISHI HIDEKI
IPC: G01M15/04
Filed: 2000-04-26
Abstract: This invention provides a map preparing method used for an engine testing
apparatus or a vehicle testing apparatus capable of preventing a peculiar
driving state from being generated. 
     This invention provides a map preparing method used for an engine testing
apparatus or a vehicle testing apparatus comprising the steps of: varying a
throttle valve from its fully closed position to its fully opened position
while keeping rotation of an engine constantly, carrying out operation for
storing an output torque N m  at that time using at least three kinds of
different engine rotation number, determining each of obtained torque curves A∼
E as actual machine data, and preparing a map based on the actual machine date,
characterized by comprising the steps of: describing each of the torque curves A
∼E on the same X-Y plane when a map is prepared based on the actual machine
data; converting actual machine data function for describing torque approximate
curves a ∼ e with respect to throttle opening degrees (X axis) on the same X-Y
plane while making approximations to the torque curves; judging whether there
exists intersection of torque approximate curves a ∼ e; and automatically
correcting one of the torque approximate curves c which can be judged as
peculiar such that a value Y 1  of y-piece of the torque approximate curve c which
is seemed to be peculiar among the intersecting torque approximate curves b,c
in the judging step assumes a medium value Y 2  , Y 3  of values of y-pieces of each
of the vertically adjacent torque approximate curves b,d. 
     And this invention provides a map preparing method used for an engine
testing apparatus or a vehicle testing apparatus capable of enhancing the
simulation accuracy. 
     This invention provides a map preparing method used for an engine testing
apparatus or a vehicle testing apparatus comprising the steps of: calculating
an average value in throttle valve opening direction S and an average value in
throttle valve closing direction G from variation of the throttle valve
operation speed 33; determining the average value of the throttle valve in the 
throttle valve opening direction S obtained by the calculation as a
representative value corresponding to the throttle valve operating in the
throttle valve opening direction in a mode driving, operating the throttle
valve in its opening direction in a state where the engine rotation number is
made constant by this representative value and describing the torque curves 35
with a plurality of different engine rotation number, and preparing a map in
the throttle valve opening direction based on the obtained torque curves 35,
determining the average value of the throttle valve in the throttle valve
closing direction G obtained by the calculation as a representative value
corresponding to the throttle valve operating in the throttle valve closing
direction in a mode driving, operating the throttle valve in its closing
direction in a state where the engine rotation number is made constant by this
representative value G and describing the torque curves 36 with a plurality of
different engine rotation number, and preparing a map in the throttle valve
closing direction based on the obtained torque curves 36. 
     And also this invention provides an engine testing apparatus capable of
carry out a simulation of an actual vehicle running with high accuracy. 
     This invention provides an engine testing apparatus comprising a
dynamometer 3 connected to an output section 2a of an engine 2 under test which
is to be tested, a dynamo controller 3' for controlling the dynamometer 3, and
an actuator 5 for controlling a throttle opening degree of the engine 2 under
test, the dynamo controller 3' and the actuator 5 are controlled to adjust an
output of the engine 2 under test, wherein commands based on a temperature
pattern 58 obtained based on temperature data of various portions around the
engine obtained when an actual vehicle running is tested in accordance with a
running pattern on a chassis dynamo from an apparatus for controlling the
entire apparatus to various temperature adjusting devices 51 provided around
the engine 2 under test.