JPH0723859B2 - Dynamometer control method for driving load test - Google Patents

Description

The present invention relates to a vehicle traveling simulator used in an automobile factory, an automobile repair shop, or the like, that is, by absorbing a force generated by an automobile to stop the vehicle body. A chassis dynamometer that allows you to simulate the state of a car running on an actual road while remaining
Alternatively, an engine driving simulator, that is, an engine dynamometer capable of imitating a force generated by the engine to simulate a state in which the engine is installed in an automobile and is actually traveling on a road. The present invention relates to a control method of a dynamometer for a running load test.

[Conventional technology]

FIG. 4 shows a schematic configuration of a conventional chassis dynamometer. In the figure, 1 is a rotary roller on which a drive wheel 2a of a test vehicle 2 is placed, and 3 is interlocked with a rotary roller 1 via a shaft 4. The power absorption unit is, for example, a DC dynamo or an AC dynamo that also has a driving capability. Reference numerals 5 and 6 are flywheels and speed sensors provided on the shaft 4, respectively. Reference numeral 7 is a torque sensor provided in the power absorption unit 3, and reference numeral 8 is a power absorption control unit that drives and controls the power absorption unit 3 based on a control signal s given from the running resistance generator 9. Reference numeral 10 is an operation pattern generator, and 11 is a pattern display which receives the output of the operation pattern generator 10 and displays a speed pattern.

Thus, in the chassis dynamometer with the above configuration,
When the driver drives the vehicle 2 according to the speed pattern displayed by the pattern display 11 (indicated by the solid line A in FIG. 5. The vertical axis and the horizontal axis in FIG. 5 indicate traveling speed and time, respectively), The rotary roller 1 rotates in response to the rotation of the drive wheel 2a. Due to the rotation of the rotary roller 1, the actual inertial force corresponding to the actual acceleration in the flywheel 5 (shown by an imaginary line F in FIG. 7. The vertical axis in FIG.
The horizontal axis represents the magnitude of inertial force and time, respectively. ) Occurs, and the actual running resistance corresponding to the running speed in the power absorption unit 3 (shown by a virtual line D in FIG. 6. The vertical axis and the horizontal axis in FIG. 6 represent running resistance and time, respectively).
As a result, the vehicle 2 actually travels according to the speed (indicated by an imaginary line H in FIG. 8. Note that the vertical axis and the horizontal axis in FIG. 8 represent traveling load and time, respectively).
Is applied.

[Problems to be solved by the invention]

By the way, a certain error range is set in the speed pattern, and the instantaneous acceleration (actual acceleration) is different from the acceleration (target acceleration) determined by the speed pattern depending on the driving method. The applied traveling load (actual traveling load) may vary greatly depending on the driving method resulting from the degree of skill of the driver.

Therefore, when the actual traveling load is obtained by detecting the actual traveling speed by the speed sensor 6 and inputting this to the traveling resistance generator 9 to determine the actual traveling resistance based on the actual traveling speed as in the conventional case, The actual running load was affected by the variation in the actual acceleration, and as shown by a virtual line H in FIG.

When the flywheel 5 generates an inertial force due to the actual acceleration as described above, and the running resistance generator 9 obtains the signal s for controlling the power absorption unit 3 in consideration of the actual speed, It was against the intent of defining a speed pattern that a test with excellent reproducibility was performed.

Further, the conventional engine dynamometer has substantially the same configuration as the chassis dynamometer shown in FIG. 4, except that the rotary roller 1 is not provided and the power absorbing section 3 is directly connected to the output shaft of the engine under test. A flywheel corresponding to the amount of inertia determined by the vehicle type of the automobile is attached to the shaft, and the load corresponding to the actual engine rotational acceleration and target speed is supplied to the engine, but this engine dynamometer also There was the same problem as described above.

An imaginary line B in FIG. 5 shows a change in actual speed with time, and solid lines C, E and G in FIGS. 6 to 8 show a target running resistance, a target inertial force and a target running load, respectively. .

The present invention has been made in consideration of the above matters, and an object thereof is to apply a running load with excellent reproducibility to a test vehicle or a test engine that is not affected by a driving method or the like. It is to provide a control method of a dynamometer for a running load test.

[Means for solving problems]

In order to achieve the above-mentioned object, a method for controlling a dynamometer for a running load test according to the present invention is a vehicle type, an inertial amount peculiar to the mechanical system of the dynamometer, and a control signal obtained based on a target operation pattern. The feature is that the power absorption unit is controlled.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a chassis dynamometer to which the present invention is applied. The members denoted by reference numerals 1 to 4, 6 to 8 and 10, 11 in the figure are the same as those denoted by the same reference numerals in the conventional example shown in FIG.

The major difference between the present invention and the conventional example is that the power absorption control unit 8
The signal S for controlling the vehicle speed is obtained based on the vehicle type, the inertia amount inherent to the mechanical system of the dynamometer, and the target driving pattern.

Thus, in FIG. 1, the PG is a pattern generation unit and is composed of an operation pattern generator 10 and a running resistance pattern generator 12. In the present embodiment, the driving pattern generator 10 outputs a target traveling pattern RP as a target driving pattern, and the target traveling pattern RP is input to the traveling resistance pattern generator 12. The target driving pattern
The RP has a pattern as shown by a solid line A in FIG. 5, for example. The traveling resistance pattern generator 12 obtains a target traveling speed V from the target traveling pattern RP.

The target traveling pattern RP is input to the pattern display 11 in synchronization with the target traveling pattern RP input to the traveling resistance pattern generator 12, the target traveling speed V is displayed, and the speed sensor 6 The actual speed v from is input and the actual speed v is displayed.

I, the inertia amount in each speed determined by R _L vehicle models respectively it is running resistance, I _m is the rotation roller 1, the machine system specific inertia of the power absorption unit 3 such as a chassis dynamometer, each of these quantities I, _RL and _Im are input to the running resistance pattern generator 12 by an appropriate method and stocked.

The traveling resistance pattern generator 12 calculates the target traveling speed V, the inertia amounts I, _Im , and the traveling resistance _RL based on the target traveling speed V, A control signal S represented by the following is output, and the control signal S is input to the power absorption control unit 8 and the power absorption unit 3 is controlled based on the control signal S.

Thus, the driver drives the vehicle 2 so that the target traveling speed V displayed on the pattern display 11 and the actual speed v from the speed sensor 6 match.

On the other hand, the running resistance pattern generator 12 of the pattern generating unit PG outputs the control signal S represented by the above formula (1), and the power absorption control unit 8 outputs an absorption command based on the control signal S. 3 to drive and control the power absorption unit 3 to give the vehicle 2 a running load equivalent to the target load.

Now, the magnitude of I _m, for example, when the rotation roller 1 having a diameter of 220 mm, length 2000 mm, is about 100 to 200 kg. Therefore,
If I _m = 150 kg, when the weight of the vehicle under test is 1500 kg, the variation in inertial force due to the variation in acceleration due to the driving method can be reduced to 1/10 (150/1500). Since the variation can be reduced to 1/4 (150/600) even when the weight of the vehicle is 600 kg, a highly accurate running load can be applied to the vehicle without requiring skill to perform mode driving. It can be added.

2 and 3 show changes in inertial force and running load over time in the method of the present invention. In FIG. 2, the vertical axis and the horizontal axis represent inertial force and time, respectively, and the vertical axis in FIG. The abscissa indicates the traveling load and time, respectively.

Further, in FIG. 2, J is the target inertial force. K is the inertial force of the artificial wheel absorbed by the power absorber 3. L is the actual inertial force absorbed by the mechanical system such as the rotating roller 1. Are shown respectively. Further, in FIG. 3, M is a target traveling load, and N is a traveling load in the present invention.

As shown in FIG. 3, it is understood that the traveling load N according to the present invention is very close to the target traveling load M and a desired traveling load can be applied to the vehicle 2.

As can be understood from the above description, in the present embodiment, the traveling load to be absorbed by the power absorbing unit 3 is the target traveling load minus the load in the mechanical system such as the rotating roller 1, so that the traveling on the actual road is performed. I try to be the same as the load.

Therefore, even if the signal S from the running resistance pattern generator 12 is the target value that the power absorber 3 actually wants to absorb,
Alternatively, the mechanical loss may be subtracted from the load actually required on the road with the drive wheels set in the chassis dynamometer.

That is, in the above embodiment, the control signal S for controlling the power absorption unit 3 is set to the inertia amount _Im and the running resistance R _L determined by the vehicle type, the inertia amount I peculiar to the mechanical system of the chassis dynamometer, and the target running speed V. Trying to get based on.

In place of the target travel pattern RP, an acceleration pattern generator and a travel resistance pattern generator are provided, and the acceleration pattern and the travel resistance pattern generator obtained from these pattern generators are processed in synchronism with each other. The control signal S may be obtained.

The target travel pattern RP may be obtained by a recording device such as a magnetic tape or a magnetic disk built in the operation pattern generator 10, or may be input by an external device such as a computer.

Further, the running resistance may be calculated by the difference or differentiation of the running speed signal obtained from the target running pattern RP. Further, an operation pattern generator may be provided separately from the operation pattern generator 10, and the operation pattern may be sent from the operation pattern generator to the pattern generator 11 in synchronization with the operation pattern generator 10.

Further, in the embodiment shown in FIG. 1, the output a of the power absorption unit 3 is detected by the torque sensor 7, and this output a is fed back to the point W to output the output a and the signal S.
However, if the absorption characteristic of the power absorption unit 3 is stable, it may be controlled by an open loop. In this case, since it is not necessary to use a feedback control device having a high-speed response, the configuration is simplified and the cost is reduced.

When the chassis dynamometer configured as described above is used only for the fuel consumption / exhaust gas test of an automobile, in the process of consuming fuel, that is, the process in which the automobile is generating a driving force, the power absorption unit 3 reduces the force. It is necessary to absorb, but the braking process of the car (eg Q ₁ , Q ₂ ,
Since in the Q ₃ moieties) it is not necessary to perform the absorption, as the power absorbing unit 3 AC dynamo having also a driving capability, DC
In addition to the dynamo, a disc brake, a powder brake, an eddick, a DC or AC dynamo generator with a resistance load, a motor capable of controlling the absorption force, or the like may be used. When the power absorbing unit 3 is composed of a member having no driving ability as described above, this kind of chassis dynamometer can be constructed at low cost.

The method of the present invention is not limited to the above chassis dynamometer, but can be applied to an engine dynamometer. In this case, the control signal S for controlling the power absorption unit 3 may be obtained based on the inertia amount and running resistance determined by the vehicle type, the inertia amount inherent to the mechanical system of the engine dynamometer, and the target engine speed. .

〔The invention's effect〕

As described above, the control method of the dynamometer for the running load test according to the present invention is the power absorption by the control signal obtained based on the vehicle type, the inertia amount inherent to the mechanical system of the dynamometer, and the target operation pattern. Since the parts are controlled, it is possible to apply a running load with excellent reproducibility that is not affected by the driving method or the like to the test vehicle or the test engine, and therefore a highly accurate test can be performed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a chassis dynamometer to which the method of the present invention is applied, FIG. 2 is a diagram showing an inertial force when a test is performed using the chassis dynamometer, and FIG. 3 is also a running load. FIG. 4, FIG. 4 is a schematic configuration diagram showing a conventional example, FIG. 5 is a diagram showing an example of a running pattern, FIG. 6 is a diagram showing changes in running resistance with time, FIG. 7 and FIG. It is a figure for demonstrating the problem of a prior art example. 3 ... Power absorber, 12 ... Travel load pattern generator, S
...... Control signal, _RL ...... Running resistance determined by vehicle type,
Inertia amount determined by the I ...... model, I m _...... mechanical system-specific inertial amount.

Claims (1)

[Claims] 1. A running load test, characterized in that a power absorbing section is controlled by a control signal obtained based on a vehicle type, an inertial amount peculiar to a mechanical system of a dynamometer, and a target operation pattern. Dynamometer control method.