U.S. patent application number 10/040431 was filed with the patent office on 2002-07-11 for testing system and method for automotive component using dynamometer.
This patent application is currently assigned to Kabushiki Kaisha Meidensha. Invention is credited to Suzuki, Masahiko.
Application Number | 20020091471 10/040431 |
Document ID | / |
Family ID | 18871731 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020091471 |
Kind Code |
A1 |
Suzuki, Masahiko |
July 11, 2002 |
TESTING SYSTEM AND METHOD FOR AUTOMOTIVE COMPONENT USING
DYNAMOMETER
Abstract
In testing system and method for an automotive vehicular
component such as an engine, a system monitor section sets required
items including a vehicular specification and a running resistance
of the vehicle and outputs the set required items to a measurement
controlling section, a model generating section is provided in
which a simulation model including a vehicular vertical vibration
model constituted by a vehicular suspension spring and a tire
spring and a spring model of an inertia system is set, a vehicular
model execution controlling section executes a vehicular model
simulation for the vehicular component to be tested by introducing
at least an acceleration signal and a clutch signal from the
measurement controlling section and the simulation model from the
model generating section and outputs control signals to the
inverter and the electronic control section so as to control the
vehicular component to be tested.
Inventors: |
Suzuki, Masahiko; (Shizuoka,
JP) |
Correspondence
Address: |
FOLEY AND LARDNER
SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
Kabushiki Kaisha Meidensha
|
Family ID: |
18871731 |
Appl. No.: |
10/040431 |
Filed: |
January 9, 2002 |
Current U.S.
Class: |
701/32.9 ;
73/118.02 |
Current CPC
Class: |
G01M 15/02 20130101 |
Class at
Publication: |
701/29 ;
73/116 |
International
Class: |
G06F 019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 11, 2001 |
JP |
2001-003376 |
Claims
What is claimed is:
1. A testing system for an automotive vehicular component,
comprising: a dynamometer linked to the vehicular component to be
tested via a torque meter and a rotary shaft, the dynamometer being
controlled by means of an inverter; a servo driver; an electronic
controlling section, the vehicular component to be tested being
controlled by outputs of the servo driver and electronic
controlling section; a system monitor section that monitors and
sets required items including a vehicular specification and a
running resistance of the vehicle and outputs required items
including the vehicular specification and the running resistance to
a measurement controlling section; a model generating section
connected to the system monitor section via a transmission path and
in which a simulation model including a vehicular vertical
vibration model constituted by a vehicular suspension spring and a
tire spring and a spring model of an inertia system is set; and a
vehicular model execution controlling section that executes a
vehicular model simulation for the vehicular component to be tested
by introducing at least an acceleration signal and a clutch signal
from the measurement controlling section and the simulation model
from the model generating section and outputs control signals to
the inverter and the electronic control section so as to control
the vehicular component to be tested.
2. A testing system for an automotive vehicular component as
claimed in claim 1, wherein the system monitor section is further
arranged to execute modifications of a structure of the simulation
model and required items including parameters in the simulation
model in the model generating section utilizing a Graphical User
Interface.
3. A testing system for an automotive vehicular component as
claimed in claim 1, wherein the vehicular component to be tested is
an engine of the vehicle and the simulation model comprises a
transmission simulation model and wherein the electronic
controlling section comprises an engine controller, a transmission
controller, and a diagnosis input/output section, the engine
controller receiving a coolant temperature signal, a throttle
position signal, and an electronic fuel injection signal from the
engine and the transmission controller executing an input and
output of signals from and to the transmission simulation
model.
4. A testing system for an automotive vehicular component as
claimed in claim 1, wherein the vehicular model execution
controlling section comprises: a model unit in which a vibration
system dynamic characteristic of a torque transmission system of
the vehicle is modeled and is set; and a resonance suppression
control section to execute a resonance vibration suppression
control for the torque transmission system.
5. A testing system for an automotive vehicular component as
claimed in claim 4, wherein a resonance point of a resonant
frequency of the testing system is set to a frequency placed in a
vicinity to 100 Hz and the resonance suppression control executed
in the resonance suppression control section of the vehicle model
execution controller is based on the set resonance point
frequency.
6. A testing system for an automotive vehicular component as
claimed in claim 1, wherein the vehicular component to be tested is
an engine and the servo driver comprises an opening angle
controlling section that is provided with a learning function on an
actual vehicular driving mode and outputs a stroke opening angle
correction value corresponding to a vehicle speed command value
from the measurement controlling section when the vehicle speed
command value is inputted therein from the measurement controlling
section; an engine characteristic memory section that previously
stores an engine output characteristic and outputs a required
opening angle predicted value on the basis of the vehicle speed
command value and the stroke opening angle correction value; an
engine-and-vehicle-speed conversion section that detects a
revolution speed of the engine and outputs an opening angle
amendment value which is a deviation value between the detected
revolution speed of the engine to be tested and the vehicle speed
command value; and a speed limit section that adds the required
opening angle predicted value to the opening angle amendment value
to provide an added result value and sets a speed limit value by
introducing the vehicle speed command value and the added result
value to the opening angle controlling section section.
7. A testing system for an automotive vehicular component as
claimed in claim 1, further comprising serial communication devices
interposed between the controller and the inverter to provide
signal transmission and receipt thereof between the controller and
the inverter.
8. A testing method for an automotive vehicular component,
comprising: providing a dynamometer linked to the vehicular
component to be tested via a torque meter and a rotary shaft, the
dynamometer being controlled by means of an inverter; providing a
servo driver; providing an electronic controlling section, the
vehicular component to be tested being controlled by outputs of the
servo driver and electronic controlling section; setting required
items including a vehicular specification and a running resistance
of the vehicle, monitoring with a system monitor; outputting
required items including the vehicular specification and the
running resistance to a measurement controlling section; providing
a model generating section connected to the system monitor section
via a transmission path and in which a simulation model including a
vehicular vertical vibration model constituted by a vehicular
suspension spring and a tire spring and a spring model of an
inertia system is set; executing a vehicular model simulation for
the vehicular component to be tested by introducing at least an
acceleration signal and a clutch signal from the measurement
controlling section and the simulation model from the model
generating section; and outputting control signals to the inverter
and the electronic control section so as to control the vehicular
component to be tested.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to testing system and method
for an automotive component such as an engine with a
dynamometer.
[0003] 2. Description of the Related Art
[0004] Various types of vehicular component testing systems have
been proposed to test a performance of the vehicular component. The
vehicular component includes an engine, a transmission, a
differential gear, and so forth. Such a previously proposed testing
system as described above is an engine bench test constituted by an
engine bench test constituted by a combination of an engine drive
system and a dynamometer absorption system and a power train bench
test constituted by a dynamometer drive system and a dynamometer
(energy) absorption system On the other hand, on the side of the
dynamometer DY, there are disposed a rotation detector PP and a
torque detector (e.g., a load cell) LC, so that the controls of
vehicle speed and output torque are executed on the basis of the
detected signals of these individual detectors.
[0005] Such a testing system as described above has another
previously proposed engine bench test in which the above-described
transmission is omitted and, in place of the transmission, a torque
meter (or torque sensor) is incorporated on an output shaft of the
engine.
SUMMARY OF THE INVENTION
[0006] Using the above-described testing system , there have been
executed the test of a durability of the engine, the performance
tests on a fuel economy or exhaust gas emission measurements, and
the test of a conformance to the ECU (Electronic Control Unit). In
order to achieve test results obtained as if the vehicle in which
the vehicular component(s) is mounted were running on a road, the
testing is implemented by applying a running resistance to the
vehicle component to be tested from the dynamometer in a pseudo
form. Since, however, the testing drive does not meet with an
actual environment when the components to be tested are actually
mounted on the vehicle and this vehicle is running on an actual
road, a transient fuel economy evaluation in a statutory mode
drive, a measurement result evaluation of exhaust gas emission, a
driveability of the engine or the vehicle have been mode through a
chassis dynamometer, an actual vehicular run. Therefore, in the
previously proposed vehicular component testing systems described
above have the following inconveniences.
[0007] (1) The transient performance test of the engine or the
vehicle-related components cannot be executed without using a
complete vehicle.
[0008] (2) The dynamometer DY and the engine E/G are interconnected
through the rotary shaft. Because of a low mechanical resonance
point in this system, however, a highly responsive torque waveform
cannot be transmitted from the dynamometer DY to the engine E/G,
and the highly responsive behavior on the engine side cannot be
transmitted to the dynamometer.
[0009] (3) In any previously proposed engine control, a performance
is so low that the fuel economy and exhaust gas emission data
cannot be reproduced like those at the time when the complete
vehicle is driven by a driver.
[0010] (4) For reproducing the transient state, it is necessary to
make the dynamometer highly responsive. However, a response
characteristic cannot be improved because a long delay is in the
transfer time of the signals between the controller and a control
board of the dynamometer.
[0011] It is, therefore, an object of the present invention is to
provide testing system and method for a vehicular component which
can solve at least one or each of the above-described items on
inconveniences of (1) to (4).
[0012] According to one aspect of the present invention, there is
provided a testing system for an automotive vehicular component,
comprising: a dynamometer linked to the vehicular component to be
tested via a torque meter and a rotary shaft, the dynamometer being
controlled by means of an inverter; a servo driver; an electronic
controlling section, the vehicular component to be tested being
controlled by outputs of the servo driver and electronic
controlling section; a system monitor section that monitors and
sets required items including a vehicular specification and a
running resistance of the vehicle and outputs required items
including the vehicular specification and the running resistance to
a measurement controlling section; a model generating section
connected to the system monitor section via a transmission path and
in which a simulation model including a vehicular vertical
vibration model constituted by a vehicular suspension spring and a
tire spring and a spring model of an inertia system is set; and a
vehicular model execution controlling section that executes a
vehicular model simulation for the vehicular component to be tested
by introducing at least an acceleration signal and a clutch signal
from the measurement controlling section and the simulation model
from the model generating section and outputs control signals to
the inverter and the electronic control section so as to control
the vehicular component to be tested.
[0013] According to another aspect of the present invention, there
is provided a testing method for an automotive vehicular component,
comprising: providing a dynamometer linked to the vehicular
component to be tested via a torque meter and a rotary shaft, the
dynamometer being controlled by means of an inverter; providing a
servo driver; providing an electronic controlling section, the
vehicular component to be tested being controlled by outputs of the
servo driver and electronic controlling section; setting required
items including a vehicular specification and a running resistance
of the vehicle, monitoring with a system monitor; outputting
required items including the vehicular specification and the
running resistance to a measurement controlling section; providing
a model generating section connected to the system monitor section
via a transmission path and in which a simulation model including a
vehicular vertical vibration model constituted by a vehicular
suspension spring and a tire spring and a spring model of an
inertia system is set; executing a vehicular model simulation for
the vehicular component to be tested by introducing at least an
acceleration signal and a clutch signal from the measurement
controlling section and the simulation model from the model
generating section; and outputting control signals to the inverter
and the electronic control section so as to control the vehicular
component to be tested.
[0014] This summary of the invention does not necessarily describe
all necessary features so that the invention may also be a
sub-combination of these described features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic construction diagram of a vehicular
component testing system in an exemplary embodiment according to
the present invention.
[0016] FIGS. 2A and 2B are simulation model views of a vehicular
manual transmission and of an automatic transmission which are
installed in a model unit shown in FIG. 1.
[0017] FIG. 3 is a schematic construction diagram representing
signal transfers in an electronic control unit of an engine to be
tested in the testing system shown in FIG. 1.
[0018] FIGS. 4A and 4B are a model view of a vehicular torque
transmission system dynamic characteristic in the testing system
shown in FIG. 1 and a construction block diagram representing a
transfer function to suppress a vibration at a modeled portion in a
model unit shown in FIG. 1.
[0019] FIGS. 5A and 5B are Bode diagrams each representing a gain
characteristic modeled as a first torsional vibration system of the
torque transmission system based on FIG. 4A.
[0020] FIG. 6 is a construction diagram of a servo driver in the
testing system shown in FIG. 1.
[0021] FIG. 7 is a construction diagram of a serial signal
communication device interposed between the execution controller
and an inverter.
[0022] FIG. 8 is a schematic cross sectional view of an example of
a dynamometer shown in FIG. 1.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT
[0023] Reference will hereinafter be made to the drawings in order
to facilitate a better understanding of the present invention.
[0024] FIG. 1 shows a schematic block diagram of a testing system
of a vehicular component in a preferred embodiment according to the
present invention. Reference numeral 1 designates an engine, and
reference numeral 2 designates a dynamometer, which is so connected
through a rotary shaft 1A to the engine 1 that a torque to be
generated therein can be transmitted to the engine 1. Numeral 3
designates a torque meter for detecting a torque transmitted to the
engine 1 from the dynamometer 2 and outputting the detected torque
value to a (execution) controller 10 of a vehicle model unit 7. The
torque meter is exemplified by a British Pat. No. 645,639 (the
disclosure of which is herein incorporated by reference). In the
(execution) controller 10, a current command value to control the
dynamometer 2 is generated and supplied to an inverter 20. This
inverter 20 is set with a speed signal by a speed signal setting
device(although not shown) and a revolution signal (in RPM) of the
dynamometer 2, as detected by a rotation detector PP1, is fed back
to that speed signal setting device, so that the inverter 20
controls a speed and/or torque of the dynamometer 2 on the basis of
these individual signals.
[0025] Numeral 4 designates a throttle actuator, by which a
throttle opening angle is controlled to adjust an intake air flow
to be supplied to a combustion chamber of the engine 1 and by which
the throttle opening angle is detected and fed back to a servo
driver 40. Numeral 30 designates an electronic control unit (ECU)
for controlling the engine, to which a control command is inputted
from the execution controller 10 of the vehicle model. Numeral 50
designates a measurement control unit which is constituted by a
computer for outputting a transmission (T/M) gear range position,
and an accelerator, clutch, and brake signals to the (execution)
controller 10 of the vehicle model unit 11. Moreover, this
measurement control unit 50 performs signal transmission and
receipt from and to a sequencer 60 and outputs a cooling water
temperature adjusting signal to an engine cooling water (coolant)
adjustment unit 5, an oil temperature adjusting signal to an engine
oil temperature adjustment unit 6, and a fuel temperature
adjustment signal to a fuel temperature adjustment unit 7.
[0026] Numeral 70 designates a console for controlling accelerator
and clutch positions and so on externally from an outside. Numeral
80 designates a computer acting as a system monitor unit to
measure/monitor, to set an automatic drive scheduler and vehicle
specifications (e.g., T/M parameters), to set a running resistance,
to collect/set engine maps, to process data, and so on. Numeral 90
designates a model generating unit constituted by a computer for
generating the vehicle model on the basis of individual constants
by introducing running resistance parameters sent via a
transmission route 9.
[0027] With reference to the block diagram of FIG. 1, the
aforementioned items of conveniences (1) to (4) are solved, as will
be specifically described in the following.
EXAMPLE 1
[0028] In a case where a vehicular component to be tested is the
(internal combustion) engine 1, as shown in FIG. 1, the engine 1 is
placed on a bench, and this engine 1 is connected directly to the
dynamometer 2 through the torque meter (TM) 3 and the rotary shaft
1A. In order to execute a simulation precisely, the torque meter 3
is arranged in such a way that it can directly measure the output
torque at the output portion (shaft) of the engine 1. For the
output revolution of the engine in RPM, moreover, an revolution
detector PP2 is arranged at the same position as that of the torque
meter 1 of the engine output portion.
[0029] Thus, the testing system is constructed to include the
engine 1(containing a flywheel FW), the torque meter 3, the rotary
shaft 1A and the dynamometer 2. In this system, the torque meter 3,
the rotary shaft 1A and the dynamometer 2 subsequently connected to
the engine 1 are, desirably, low inertia system components whose
inertia is as low as possible. For this low inertia, a diameter of
a rotor of the dynamometer 2 is, desirably, extremely made small.
For example, inertial value (in Kgm.sup.2) was improved from about
1.3 of the conventional system components to about 0.1 when the
dynamometer 2 , for example, disclosed in a Japanese Patent
Application No. 2000-269738 filed in Japan on Sep. 6, 2000 was used
as the dynamometer 2 shown in FIG. 1, an IM (Induction Motor) motor
was exchanged to a PM (Poly-phase Motor) motor to improve an
efficiency, and the cooling method was changed from an air to water
cooling. FIG. 8 shows the structure of the dynamometer (D/M) 2
disclosed in the Japanese Patent Application No. 2000-269738. The
dynamometer shown in FIG. 8 includes: the rotor 2000 supported on
bearings 600 and 700; a stator 1000 disposed at a position opposing
to the rotor; a cooling liquid opening 1600 penetrated through a
frame 1300 of the dynamometer and the stator for causing a cooling
liquid flow into a space between the rotor and the stator; and can
3000 interposed between a winding 1200 of the stator and the rotor
for preventing a direct contact of an agitating cooling liquid due
to a revolution of the rotor on the winding 1200 and an iron core
1100 of the stator, a plurality of cooling liquid openings (9200,
1000) being provided on the can which is near to a bracket 900 or
800.
[0030] Moreover, an inertial value was improved from about 0.5 to
about 0.2 (Kgm.sup.2) by replacing a material from a steel to glass
fibers and was improved from about 0.65 (Kgm.sup.2) to about 0.3
(Kgm.sup.2) by replacing the torque meter TM 3 into that of a
coupling type.
[0031] Therefore, a total inertial value according to the
above-described three replacements due mainly to the light weight
was improved to indicate about 0.42 Kgm.sup.2 (although a
comparative example without the above-described replacements
indicated about 2.45 Kgm.sup.2 ).
[0032] Furthermore, by achieving a highly responsive
controllability for the dynamometer 2, the simulation could be made
so highly precise as close (approximated) to that of an actual
vehicle without applying a severe shock which would occur during a
control delay time to the component to be tested such as the
engine.
[0033] FIGS. 2A and 2B show generated models for the components
except the engine to be tested for a simulation. Specifically, FIG.
2A shows the model of a case of a manual 15 transmission MT and
FIG. 2B shows the case of an automatic transmission AT. The
portions, as indicated by dot-dot-and-dash lines in FIGS. 2A and
2B, correspond to model unit 11 shown in FIG. 1.
[0034] Each of the simulation models (in the model unit 11) shown
in FIGS. 2A and 2B is constituted by a spring model of a 4-inertia
system, a suspension, and vertical vibrations (i.e., sprung(vehicle
body)--unsprungmass (tire wheels) vibrations) by tire springs.
[0035] Individual values of coefficients of the components shown in
FIG. 2A and 2B are inputted to the model unit 11 shown in FIG. 1 as
model parameters from the model generating unit 90 shown in FIG. 1.
Then, the model parameter inputted model shown in FIGS. 2A or 2B
and are transmitted through a transmission route to the execution
controller 10 of the vehicle model system. The execution controller
10 executes a simulation using the model whose parameters are
inputted therein. It is noted that, although the model structure of
a previously proposed testing system (which is a comparative
example to the testing system in the embodiment shown in FIG. 1) is
fixed (one model with only the fixed model parameters), the testing
system in the embodiment according to the present invention has
such a feature that, in the testing system including the model
generating unit 90 and the system monitor unit 80 shown in FIG. 1,
the simulation structure itself can be modified by a simulation
tool utilizing a GUI (Graphical User Interface). By means of the
model generating unit 90 and the system monitor unit 80, therefore,
not only the parameters but also the model structure itself can be
changed so that every type of vehicular components can be
simulated.
[0036] A vehicle model, which is generated through the GUI, is
down-loaded so as to enable an execution in the execution
controller 10. Various commands are issued from the controller 10
to the electronic control unit 30 of the engine E/G 1 shown in FIG.
1.
[0037] FIG. 3 shows a signal transfer state in the electronic
control unit 30 with the engine 1 and controller 10 in which the
model is installed in the down-load form as the automatic
transmission 13. In a case of FIG. 3, it is necessary to transmit
and receive required signals among the electronic control unit 30,
the engine E/G 1, and the execution controller 10 to implement a
vehicular simulation. For this purpose, the electronic control unit
30, as shown in FIG. 3, includes an engine controller 31, a
transmission controller 32, a diagnosis input/output unit 33, and
so on. The engine controller 31 receives the various signals from
an electric fuel injection control (for the fuel electronic
injection quantity and start timing control), a throttle position
sensor for detecting an opening angle of an engine throttle valve
and a water (coolant) temperature sensor in the engine 1 and
transmits and receives signals to and from the transmission
controller 32. In addition, this transmission controller 32 outputs
related commands to shift solenoids No. 1 and No. 2, linear
solenoids No. 1 and No. 2 and a lock-up solenoid of mode 113 of a
transmission body modeled in the execution controller 10, and
receives individual signals of a transmission (T/M) input
revolution sensor, an oil temperature sensor, a speed sensor (SP2)
and a neutral sensor from the model 13 of the transmission body. In
addition, the transmission controller 32 receives the individual
signals from an overdrive switch, a stop lamp switch and a vehicle
speed sensor from the execution controller 10 and outputs a model
signal to an overdrive indicator.
[0038] The signals of the individual controllers 31 and 32 are
transferred through the diagnosis input/output unit 33 with signals
of a diagnosis connector so that the abnormality-related signals of
the engine are simulated.
[0039] With the testing system construction thus described above
with reference to FIGS. 1 through 3, the transient performance
tests of the engine can be executed without using a completed
vehicle.
EXAMPLE 2
[0040] In the second example, in order to solve the foregoing item
on inconveniences (2), a highly responsive torque waveform is
transmitted from the dynamometer 2 to the engine 1.
[0041] FIGS. 4A and 4B show an internal model on the vibration
suppression (resonance) control unit 12 shown in FIG. 1.
Especially, FIG. 4A shows a model for a dynamic characteristic of a
torque transmission system, and FIG. 4B shows a functional block
diagram of a transfer function for damping the vibrations at a
modeled portion (model unit 11). This modeled portion shown in FIG.
4B is the rotary shaft 1A connecting the engine 1 and the
dynamometer 2 shown in FIG. 1, and the symbols shown in FIGS. 4A
and 4B have the following meanings. That is to say, in FIGS. 4A and
4B, a symbol Te denotes an engine torque; a symbol .omega.e denotes
the engine speed in RPM; a symbol Je denotes an inertial moment of
the engine 1; a symbol De denotes a viscous friction coefficient of
the engine 1; a symbol Kc denotes a spring constant of the rotary
shaft 1A interposed between the dynamometer 2 and the engine 1; a
symbol Kd denotes a viscous friction coefficient of the rotary
shaft 1A; a symbol Tp denotes a shaft (axial) torque; a symbol Jd
denotes an inertial moment of the dynamometer 2; a symbol Dd
denotes a viscous friction coefficient of the dynamometer 2; a
symbol Td denotes a torque of the dynamometer 2; and a symbol
.omega.d denotes an RPM (revolution speed) of the dynamometer 2. In
addition, 1/s denotes an integrator. Other symbols denote constant
values. Herein, a resonance signal of resonance control unit 12 is
outputted as a current command to the inverter 20.
[0042] In the engine bench of the testing system in the comparative
example to the exemplary embodiment shown in FIG. 1, the
transmission or clutch is used to make a coupling of engine 1 to
the dynamometer 2 so that a mechanical resonance point of the
system has been low. In the engine bench, moreover, the drive speed
in RPM range is from an engine idling speed of the vehicle up to
about 8,000 rpm. If the resonance has its point within that range,
it may invite a mechanical breakage of the testing system.
Therefore, a resonance point is set at a lower RPM than the engine
idling speed value (because the inertial value or a damping
constant value makes it difficult to set the revolution speed value
in RPM higher than 8,000 rpm).
[0043] On the other hand, a vibration of a drive system or a
chassis vibration of a generally available vehicle has a frequency
of 100 Hz or less (e.g., about 50 Hz). Therefore, a resonance point
is set to about 10 to 20 Hz equal to or below the idling speed in
RPM when it is set at the idling value, as described above. In the
testing system in the embodiment according to the present
invention, however, a resonance point of the system is set to such
a value in the vicinity to 100 Hz that will not influence the
control. This resonance point is subjected to a robust control
through the resonance control unit 12 and the inverter 20, thereby
to suppress the resonance so that a shaft torque control can be
made flat and stable to 100 Hz or higher. Here, this setting range
of the resonance point has a lower limit at the vibration frequency
of the drive system of the automobile and an upper limit at a
control frequency of the current control unit (ACR) of the inverter
for controlling on the basis of a current command value. By the
performance, therefore, there is determined a frequency in the
vicinity of or over the resonance point of 100 Hz, for example.
[0044] On the other hand, the block diagram of FIG. 4B of a
transfer function for the vibration suppression at the model
portion is constructed, with consideration of the suppression
performance of disturbances and the robustness against the system
parameter fluctuation.
[0045] FIGS. 5A and 5B are Bode diagrams illustrating the gain
characteristics of the model, in which the torque transmission
system based on FIG. 4A is modeled as a primary torsional vibration
system. FIG. 5A presents a closed loop gain from the dynamometer
torque to the shaft torque of the case without the suppression
control. When the mechanical resonance point was set at 635 rad/sec
(corresponding to 101 Hz), the gain (G) was 24 dB. On the contrary,
the closed loop gain from the shaft torque command value to the
shaft torque of the case in which the resonance suppression control
is executed by the block of FIG. 4B was a gain G of -3.9 dB for
resonance point of 635 rad/sec, as illustrated in FIG. 5B. As
apparent from FIG. 5B, the resonance point is suppressed so that
the drive can be done without deteriorating a transmission
characteristics to 100 Hz or higher.
EXAMPLE 3
[0046] This example contemplates to reproduce the fuel economy and
exhaust gas emission data which are similar to those when the
driver drives the actual vehicle.
[0047] FIG. 6 shows a construction of the servo driver 40 shown in
FIG. 1. Reference numeral 41 designates a mode drive vehicle speed
command unit. A vehicle speed command from this command unit 41 is
outputted to an engine/vehicle speed control 42, an engine
characteristic memory unit 43, an opening correction unit 44, and a
speed limiter unit 45. The engine/vehicle speed control unit 42 is
operated on the basis of the input vehicle speed command and a
vehicle speed detected signal fed back by an
engine-speed/vehicle-speed conversion unit 47, and outputs the
deviation signal as an opening correction value. The opening
correction unit 44 has a function to make a learning drive in
advance on the actual driving mode, and is, for example,
constituted by a CMAC (Cerebellar Model Arithmetic Computer)
operational amplifier which is exemplified by a U.S. Pat. No.
5,954,783 (the disclosure of which is herein incorporated by
reference), the table values of which are so adjusted that an
output value and an output target value for an input value may be
equalized by using the former as a learning value and the latter as
a teaching value. From this opening correction unit 44, the opening
correction value corresponding to the vehicle speed command is
outputted to the engine characteristic memory unit 43. This memory
unit 43 is stored with the characteristic values of the engine
torque-versus-opening so that the predicted necessary opening value
is selected from the stored characteristic values on the basis of
the vehicle speed command and the opening correction value and is
outputted to an adder 48. This adder 48 adds the opening correction
value from the engine vehicle speed control unit 42 and the
predicted necessary opening value in a common polarity, and outputs
the sum to the speed limiter unit 45. This speed limiter unit 45
sets the limiter value of the opening stroke on the basis of the
vehicle speed command and the added signal from the adder. This set
limiter value is outputted as the opening command value to an
opening control unit 46 of the actuator, and this control unit 46
outputs the limiter value as the current command value to the
throttle actuator 4 so that the throttle opening is controlled. In
accordance with this opening, therefore, the engine 1 is controlled
which is detected by the rotation detector PP2 and fed back through
the engine/vehicle-speed conversion unit 47 to the engine vehicle
speed control unit 42.
[0048] The engine control has pursued the following performance to
the vehicle speed or the command so that it has a remarkably quick
response to the opening. However, the testing object such as the
fuel economy measurement or the exhaust gas emission measurement
has a tendency to become worse than that at the human-driven time.
The causes for this tendency are considered to come from the
following:
[0049] a. The opening stroke speed is higher than necessary;
[0050] b. The running mode is read in advance as by the driver so
that the next operation cannot be prepared; and
[0051] c. The mode drive cannot be made unlike the man drive while
knowing the characteristics of the engine.
[0052] According to the present invention, a speed limiter unit 45
is provided to cope with the above-described item a, so that a
limit is provided against a differential value of the opening
stroke as a countermeasure of the item a.
[0053] Against the item b, moreover, there is provided the opening
correction unit 44, which is constructed to learn the drive in
advance for the actual driving mode. lo Against the item c, still
moreover, the engine characteristics are recorded in advance in the
memory unit 43 so that they are selected and utilized in response
to the opening command.
[0054] With this construction, it is possible to solve the
aforementioned problem (3).
EXAMPLE 4
[0055] In this example, the highly responsive dynamometer 2 is
achieved so as to realize a transient state again. In the testing
system of this kind shown in FIG. 1, generally describing, the
vehicle model execution controller 10 and the inverter 20 are
disposed at a relatively long distant position, and the command is
outputted as an analog signal from the controller to the control
panel of the inverter. Considering the countermeasure against the
noise, therefore, it is necessary to provide a filter of about 10
ms. In order to execute the resonance suppressing control at 100
Hz, as described hereinbefore, there is needed a control
responsibility of about 2 ms. Considering allowances such as 500
.mu.sec (microseconds) for the torque command operation in the
inverter 20, 100 .mu.sec for the resonance suppression value
operation in the damping control unit 12 or 1 ms for the shaft
torque detection, therefore, the delay time for transferring the
signals between the execution controller 10 and the inverter 20 has
to be 100 .mu.sec or shorter.
[0056] FIG. 7 is a construction diagram for satisfying those needs.
As shown in FIG. 7, the execution controller 10 and the inverter 20
are equipped with serial communication devices 14 and 21. These
serial communication devices 14 and 21 are exemplified by a
16-channel multiplex transmission LSI, and the signal transfer
between controller 10 and inverter 20 is executed at about 40
.mu.sec at a clock time of 20 MHz thereby to raise the speed.
[0057] According to the present invention, as has been described
hereinbefore, the testing for the vehicular component to be tested
is executed on the basis of the model of the engine or any other
vehicular component, as generated by the system monitor unit and in
the model generating unit. Therefore, the tests of the engine or
the vehicle-related component can actually be achieved not in
combination with other components but singly as the vehicle. By
utilizing the GUI, moreover, the model structure itself can be
modified so that the simulations of all vehicular components for
various types of vehicles can easily be executed.
[0058] Moreover, in a case where the engine is the vehicular
component to be tested, the individual components can be so
combined as to combine and test the transmission or the like by the
simulation with various transmissions models such as the automatic
transmission, the manual transmission or a continuously variable
transmission (CVT), even if the actual transmission is not
used.
[0059] Moreover, the resonance point of the resonance frequency of
the testing system can be set at a high frequency value so that the
vibrations to be generated in the actual vehicle can be reproduced
on the engine bench. There can be obtained the effects: to perform
the actual road running tests of the vehicle with the single
engine; to perform the drivability tests on the engine bench as on
the actual road; and to make the engine control indicating similar
fuel economy/exhaust gas emission as by the driver.
[0060] The entire contents of Japanese Patent Applications No.
2001-3376 (filed in Japan on Jan. 11, 2001) are herein incorporated
by reference. The scope of the invention is defined with reference
to the following claims.
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