JP2000314680A - Engine test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine test device which vehicle running simulation can be conducted with good accuracy. SOLUTION: A dynamometer 2 connected to an output part 1a of a sample engine 1 which is to be tested and used for simulating an actual vehicle running for a chassis dynamo, a dynamo controller 7 which controls revolution of the dynamometer 2, and an actuator 6 which controls value travel of the throttle of the sample engine 1, are provided. Here, the dynamo controller 7 and the actuator 6 are controlled to adjust the output of the sample engine 1. A new number of revolution after a wheel slip is corrected is used at simulation to control the revolution of the dynamometer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an engine test apparatus.

[0002]

2. Description of the Related Art In order to verify the performance of an automobile engine, a dynamometer connected to an output of a test engine to be tested, a dynamometer controller for controlling the dynamometer, and a throttle opening of the test engine are used. There is an engine test device that includes an actuator for controlling the degree of rotation, and controls the dynamo controller and the actuator to adjust the output of the test engine.

FIG. 3 schematically shows a general configuration of an engine test apparatus. In this figure, 1 is a test engine to be tested, 2 is a dynamometer, and 1 and 2 are dynamometers.
The output shaft 1a and the drive shaft 2a are connected via a clutch 3 so as to be connectable / separable. Reference numeral 4 denotes a clutch actuator that drives the clutch 3. Reference numeral 5 denotes a throttle of the test engine 1 which is driven by a throttle actuator 6 and its opening is controlled. Reference numeral 7 denotes a dynamometer controller that controls the dynamometer 2. 8 is a drive shaft 2 of the dynamometer 2
The torque sensor 9 provided at a is a torque amplifier that amplifies the output of the torque sensor 8 as appropriate.

[0004] Reference numeral 10 denotes a control computer as a simulator for controlling the entire apparatus, and reference numeral 11 denotes a signal conditioner unit. Computer 10
It performs calculations based on inputs from an input device (not shown) or signals from various sensors such as a torque sensor 8 provided in the device, and outputs commands to each unit of the device. The computer 10 includes, for example, a target vehicle speed pattern 12 shown in FIG.
A target vehicle speed pattern 12a as shown in (A) or a target vehicle speed pattern 12b as shown in FIGS. That is, the target vehicle speed pattern 12,
12a and 12b, the horizontal axis represents time (second), and the vertical axis represents speed (k).
m / h), which is a target running pattern to be driven.

[0005] The signal conditioner unit 1
Reference numeral 1 denotes an interface having an AD conversion function and a DA conversion function. The interface 1 performs AD conversion of signals from various sensors such as the torque sensor 8 and DA conversion of a command from the computer 10 so that the dynamo controller 7, the clutch actuator 4, A command is output to each part of the device such as the throttle actuator 6.

Incidentally, in an engine test apparatus,
Among the rotating bodies in the actual vehicle, that is, the engine among the engine, transmission, differential gear, and tire, the moment of inertia of the engine is used for the load calculation. This is because the moment of inertia of the engine is larger than the moments of other rotating bodies.

FIG. 5 shows a conventional control flow in the engine test apparatus. In FIG. 5, 13
Is a target pattern generator which is provided in the computer 10 and which causes the test engine 1 to run in a predetermined running pattern based on the target vehicle speed patterns 12, 12a, 12b inputted to the computer 10. Outputs the target speed Vr. The target speed signal Vr is input to the rotation control system 14 and the simulated vehicle control system 15.

The rotation control system 14 and the simulated vehicle control system 15 are configured as follows. First, the rotation control system 14 includes a rotation generator 16 to which the target speed signal Vr is input, a delay correction circuit 17,
8, the rotation feedback controller 19 and the dynamometer 2.

In the rotation control system 14 having the above configuration, when the target speed Vr is input to the rotation generator 16, the target rotation speed of the engine [the dynamometer rotation speed (hereinafter simply referred to as the rotation speed) Target value] R
r is output.

For example, as shown in FIG. 4B, a target rotation speed Rr converted from the target vehicle speed pattern 12a shown in FIG. 4A in a simulation is obtained. That is,
An engine rotation pattern 33 is obtained. Similarly, when the target vehicle speed pattern 12b is adopted, an engine rotation pattern 30 converted from the target vehicle speed pattern 12b is obtained as shown in FIG. Then, the target vehicle speed pattern 12a
When converting the vehicle speed into the engine rotation pattern 33 or when converting the target vehicle speed pattern 12b into the engine rotation pattern 30, the tire diameter, the final reduction ratio, and the gear ratio according to the type of the vehicle are taken into consideration.

Returning to FIG. 5, the target rotation speed Rr becomes the control target rotation speed Rctl via the delay correction circuit 17 and is output to the abutting point 18. At this butting point 18,
Since the actual rotation speed Ra of the dynamometer 2 is input, the operation amount Ud 'is set by the PI of the deviation Re between the control target rotation speed Rctl and the actual rotation speed Ra in the rotation feedback controller 19, for example. The operation amount Ud 'is sent to the dynamometer 2.

FIG. 5 shows a simulation vehicle control system 15.
Is a torque generator 20 to which the target speed Vr is input, subsequent to the target pattern generator 13 which outputs the target speed Vr.
And a point 21 to which the target speed Vr is input and a speed feedback controller 22 are connected in parallel. Further, a torque control system 27 including an addition point 23, a butting point 24, a throttle map 25, a throttle opening controller 26, and a test engine 1 is provided downstream of the torque generator 20 and the speed feedback controller 22. A simulated vehicle model 28 is provided downstream of the torque control system 27. The throttle map 25 is a map for determining a target throttle opening in engine control. The simulated vehicle model 28 is a model for calculating the driving force of the vehicle using the engine output torque and converting the driving force into a speed signal using the driving force.

In the simulated vehicle control system 15 having the above configuration, when the target speed Vr is input to the torque generator 20,
Based on this, the feedforward torque Tff, which is the output torque required for the engine, is output from the torque generator 20 to the addition point 23.

In this case, when converting the target vehicle speed pattern 12 or the target vehicle speed patterns 12a and 12b into the feedforward torque Tff, the vehicle inertia weight and the running resistance according to the type of the vehicle are taken into consideration.

The target speed Vr is compared with the actual speed Va output from the simulated vehicle model 28 at the abutting point 21, and a deviation thereof is sent to the speed feedback controller 22, where the difference is sent as the feedback torque Tfb. Is output to Then, the feedforward torque Tff and the feedback torque Tfb are added at an addition point 23 to obtain a target control torque Tctl. This target control torque Tctl is matched with the actual output torque value Ta of the test engine 1 and
The deviation Te is input to the throttle map 25 to obtain an operation target throttle opening θ.
And the operation amount Ua is set, and the operation amount Ua
Is sent to the test engine 1.

By the way, in the above-described conventional engine test apparatus, there is only one constant as a transmission efficiency constant until the output of the engine is finally transmitted to the road surface and changed to a force for accelerating the vehicle. That is, the constant is 2
This is for adjusting the rotation speed of the roller on the shaft chassis dynamo to the same rotation speed as the engine rotation speed of the actual vehicle, and taking into consideration a constant speed (steady) running operation.

[0017]

In practice, however, slippage occurs between the tires and the road surface when the vehicle is actually running. In other words, with the conventional engine test equipment, as seen remarkably with the two-axis chassis dynamo,
It was not possible to reproduce the change in the slip ratio between the tire and the roller caused by the difference in the degree of deformation of the tire during acceleration running and deceleration running.

In short, in a conventional engine test apparatus,
Since the slip could not be simulated, as shown in FIG. 6, the engine rotation pattern 30 converted from the target vehicle speed pattern 12b in the simulation performed by the conventional engine test apparatus was measured when the actual vehicle was run on the chassis dynamo. When the engine rotation patterns 31 were compared, there was a difference between the two. From FIG. 6, the engine rotation pattern 30 is the same as the engine rotation pattern 3 during acceleration.
It can be seen that the gear shifts below 1 and at the time of deceleration shifts above the engine rotation pattern 31.

In order to reproduce the engine rotation during actual vehicle running, it is necessary to consider not only the tire diameter, final reduction ratio and gear ratio, the vehicle inertia weight and running resistance but also the slip between the tire and the road surface. However, in the conventional engine test apparatus, due to lack of consideration of this point, accurate simulation could not be performed.

The present invention has been made in consideration of the above-mentioned matters, and an object of the present invention is to provide an engine test apparatus capable of performing a vehicle simulation with high accuracy.

[0021]

In order to achieve the above object, the present invention relates to a dynamometer connected to an output of a test engine to be tested, which is used to simulate actual vehicle running on a chassis dynamo. An engine test apparatus comprising: a dynamo controller that controls the rotation of the dynamo meter; and an actuator that controls a throttle opening of the test engine, and controls the dynamo controller and the actuator to adjust the output of the test engine. A tire that generates a constant-speed drive slip ratio (Sa) in a constant-speed running state in a target vehicle speed pattern, an accelerated drive slip ratio (Sb) in an accelerated running state, and a decelerated drive slip ratio (Sc) in a decelerated running state during actual vehicle running. Calculate and store in advance as data for correcting slip, These driving slip ratio (Sa),
The target engine speed (Rr) obtained by converting the target vehicle speed pattern based on the values of (Sb) and (Sc) is corrected for each of the running states, and the new target engine speed obtained by this correction is calculated. It is characterized in that the dynamometer is configured to control the rotation by using each of them at the time of simulation.

According to another aspect of the present invention, there is provided a dynamometer connected to an output of a test engine which is a test object used for simulating actual vehicle running on a chassis dynamo, and a rotation control of the dynamometer. A dynamo controller for controlling the throttle opening of the test engine and an actuator for controlling the output of the test engine by controlling the dynamo controller and the actuator. The constant speed driving slip ratio (Sa) in the high speed running condition, the acceleration driving slip ratio (Sb) in the accelerating driving condition, and the deceleration driving slip ratio (Sc) in the decelerating driving condition are used to correct the tire slip generated when the vehicle is running. Is calculated and stored in advance as A rotation speed obtained by adding a term obtained by multiplying the engine target rotation speed (Rr) by the constant speed drive slip ratio (Sa), the acceleration drive slip ratio (Sb) or the deceleration drive slip ratio (Sc) to the target rotation speed (Rr). (Rta
) ｛[Rta = Rr × (1 + Sa)], (Rtb)
[Rt b = Rr × (1 + Sb)] or (Rt c)
[Rtc = Rr × (1 + Sc)]} is a new rotational speed after the tire slip correction, and these are used at the time of simulation to control the rotation of the dynamometer. I will provide a.

In FIG. 6, the inventor of the present invention has determined that the engine rotation pattern 30 obtained by converting from the target vehicle speed pattern 12b in the conventional simulation is different from the engine rotation pattern 31 measured when the actual vehicle is running on the chassis dynamo. Was attributed to the tire slip. From this viewpoint, the drive slip ratio S
The concept was introduced. The present inventor has defined the drive slip ratio S as the average value of the ratio between the measured engine speed indicated by the engine speed pattern 31 and the engine speed indicated by the engine speed pattern 30.
In addition, since the engine rotation patterns 30 and 33 are obtained from the target vehicle speed patterns 12b and 12a including the constant speed (steady) portion, the acceleration portion, and the deceleration portion, respectively, the constant speed, acceleration, and deceleration are obtained by one driving slip ratio S. Each state cannot be covered. From this viewpoint, the inventor divided the driving slip ratio S into three types, that is, a constant speed portion, an acceleration portion, and a deceleration portion, and calculated the respective slip ratios Sa, Sb, and Sc.

For example, in FIG. 6, the acceleration drive slip ratio Sb can be obtained as follows. (1) Acceleration curve A ₁ in engine rotation pattern 31
Determining the area of ~A _8. For example, the area of the acceleration curve A ₁ is G ₁ (hatched portion). Adding these areas G ₁ ~G _8. That is, G ₁ +... + G ₈ = G. (2) The acceleration curve B ₁ in the engine rotation pattern 30
Determining the area of ~B _8. For example, the area of the acceleration curve B ₈ is R ₈ (shaded area). These areas R _{1 to} R ₈ are added. That is, R ₁ +... + R ₈ = R. (3) The ratio of both G and R is calculated, and this is calculated as the slip ratio Sb.
And That is, Sb = G / R.

The same operation is performed by using the engine rotation pattern 3
All deceleration curves C and engine rotation pattern 3 at 1
This is performed for all the deceleration curves D at 0 to obtain the slip ratio Sc.

The constant speed slip ratio Sa can be obtained by performing the same calculation.

After the data for correcting the tire slip generated during the actual running of the vehicle is thus obtained in advance, the inventor of the present invention sets the target engine speed (for each of the constant speed section, the acceleration section, and the deceleration section). Rr) is the constant speed drive slip ratio Sa.
Then, a term multiplied by the acceleration drive slip ratio Sb or the deceleration drive slip ratio Sc is added to the target rotation speed Rr to create a new rotation speed Rta, Rtb or Rtc after tire slip correction.

In the engine test apparatus having the above configuration,
In addition to the tire diameter, final reduction ratio and gear ratio, vehicle inertial weight and running resistance, which are taken into account in conventional engine test equipment, slip between tires and the road surface is taken into account. Engine speed can be accurately reproduced.

That is, the engine rotation pattern 40 converted from the new rotation speed Rta, Rtb or Rtc after the tire slip correction does not shift from the measured engine rotation pattern 31, as shown in FIG. Compared to a conventional engine test apparatus in which the control computer 10 controls the rotation of the dynamometer 2 in accordance with the engine rotation pattern 30 converted from the rotation speed Rr, the new rotation speed Rta, Rtb or Rt after the tire slip is corrected.
The engine test apparatus of the present invention in which the control computer 10 controls the rotation of the dynamometer 2 in accordance with the engine rotation pattern 40 converted from c can perform a simulation with higher accuracy.

[0030]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention, and shows an example of a control flow in the engine test apparatus shown in FIG. FIG. 2 shows a comparison between an engine rotation pattern 40 converted from the target vehicle speed pattern 12b in a simulation performed by the engine test apparatus of the present invention and an engine rotation pattern 31 measured when a real vehicle is driven on a chassis dynamo. 1 and 2 are the same as those shown in FIGS. 5 and 6, and the description thereof is omitted.

First, FIG. 1 showing a control flow in the engine test apparatus of the present invention is greatly different from FIG. 5 showing a control flow in the conventional engine test apparatus, in that a new rotational speed after tire slip correction is determined. The dynamometer 2 is configured to be divided into a speed section, an acceleration section, and a deceleration section, and the dynamometer 2 is controlled by using these sections.

This will be described in more detail with reference to the control flow shown in FIG. 1. In FIG. 1, reference numeral 41 denotes a drive slip correcting means provided between the rotation generator 16 and the delay correcting means 17.

The driving slip correcting means 41 is provided in FIG.
Acceleration curve A in the engine rotation pattern 31 shown in FIG.
A calculation function for adding all areas of ₁ to A _8, acceleration curve B ₁ .about.B in the engine rotation pattern 30 shown in FIG. 6
₈ and a function of calculating the ratio (= acceleration drive slip ratio Sb) of each of the total areas G and R obtained by the addition. In the engine rotation pattern 31 shown in FIG. An arithmetic function for adding all areas of the deceleration curve C, an arithmetic function for adding all areas of the deceleration curve D in the engine rotation pattern 30 shown in FIG. 6, and a ratio of total areas obtained by addition (= deceleration driving) Slip ratio Sc
6), a calculation function for adding all areas of the constant speed curve E in the engine rotation pattern 31 shown in FIG. 6, and an engine rotation pattern 30 shown in FIG.
An arithmetic function for adding all areas of the constant speed curve F in
Ratio of each total area obtained by adding (= constant speed slip ratio S
a) is calculated, and a term obtained by multiplying the target engine speed Rr by the acceleration drive slip ratio Sb is added to the target engine speed Rr to obtain a new engine speed Rtb after the tire slip correction. It has a function of calculating, that is, a function of calculating a new rotation speed Rt b represented by the following equation (1) for controlling the rotation of the dynamometer 2 in the acceleration unit. 1) A function of adding a term obtained by multiplying the engine target rotational speed Rr by the deceleration drive slip ratio Sc to the target rotational speed Rr to calculate a new rotational speed Rtc after tire slip correction, that is, in the deceleration unit, It has a function of calculating a new rotational speed Rt c shown in the following equation (2) for controlling the rotation of the dynamometer 2. Multiply by the drive slip ratio Sa Is added to the target rotational speed Rr to calculate a new rotational speed Rta after the tire slip correction, that is, the following equation (3) for controlling the rotation of the dynamometer 2 in the constant speed section. Has a function of calculating a new rotation speed Rta indicated by. Rta = Rr × (1 + Sa) (3)

As described above, in the control flow shown in FIG. 1, the drive slip correction means 41 is provided between the rotation generator 16 and the delay correction means 17, and the drive slip correction means 41 New target rotational speed Rt b taking into account the correction (tire slip correction)
It is also possible to obtain a new target rotational speed Rtc taking into account the drive slip correction during deceleration traveling, and to obtain a new target rotation speed taking into account the drive slip correction during constant speed traveling. The number Rt a can be obtained.

Then, by controlling the rotation of the dynamometer 2 in accordance with the new target rotation pattern expressed by the above equation (1), the engine running in the actual vehicle taking into account the slip between the tire and the road surface during acceleration running is considered. The rotation can be accurately reproduced.

Further, by controlling the rotation of the dynamometer 2 in accordance with the new target rotation pattern represented by the above equation (2), the engine running in a real vehicle taking into account the slip between the tire and the road surface during deceleration driving is considered. The rotation can be accurately reproduced.

Further, by controlling the rotation of the dynamometer 2 in accordance with the new target rotation pattern expressed by the above equation (3), the actual vehicle running while taking into account the slip between the tire and the road surface at the time of constant speed running is considered. The engine speed can be accurately reproduced.

As described above, according to the engine test apparatus of the present invention, a new target rotation pattern is created for each of the constant speed section, the acceleration section, and the deceleration section in consideration of the slip between the tire and the road surface. Since the rotation of the dynamometer is controlled in accordance with the new target rotation pattern, it is possible to accurately simulate the actual running of the vehicle and perform the engine performance test in a state closer to reality.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a control flow in an engine test apparatus of the present invention.

FIG. 2 is a diagram showing a comparison between an engine rotation pattern converted from a target vehicle speed pattern and an engine rotation pattern measured when a real vehicle is driven on a chassis dynamo in a simulation performed by the engine test apparatus of the present invention.

FIG. 3 schematically shows an entire configuration of an engine test apparatus according to the present invention.

FIG. 4A is a diagram illustrating an example of a target vehicle speed pattern. (B) is Ru FIG showing one example of the rotation target pattern.

FIG. 5 is a diagram showing a control flow in a conventional engine test apparatus.

FIG. 6 is a diagram showing a comparison between an engine rotation pattern converted from a target vehicle speed pattern and an engine rotation pattern measured when a real vehicle is driven on a chassis dynamo in a simulation performed by a conventional engine test apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Test engine, 1a ... Output part, 2 ... Dynamometer, 7 ... Dynamometer controller, 6 ... Throttle actuator, 12, 12a, 12b ... Target vehicle speed pattern,
41: drive slip correction means.

Claims (2)

[Claims] 1. A dynamometer connected to an output section of a test engine which is a test object used for simulating a real vehicle running on a chassis dynamo, a dynamo controller for controlling rotation of the dynamometer, and the test An actuator for controlling the throttle opening of the engine, wherein the engine test apparatus controls the dynamo controller and the actuator to adjust the output of the engine under test. The rate (Sa), the acceleration drive slip rate (Sb) in the acceleration running state, and the deceleration drive slip rate (Sc) in the deceleration running state are calculated and stored in advance as data for correcting the tire slip that occurs when the vehicle is running. These drive slip rates (Sa),
The target engine speed (Rr) obtained by converting the target vehicle speed pattern based on the values of (Sb) and (Sc) is corrected for each of the running states, and the new target engine speed obtained by this correction is calculated. An engine test apparatus characterized in that the dynamometer is configured to control the rotation by being used at the time of simulation. 2. A dynamometer connected to an output of a test engine which is a test object used for simulating actual vehicle running on a chassis dynamo, a dynamo controller for controlling rotation of the dynamometer, and An actuator for controlling the throttle opening of the engine, wherein the engine test apparatus controls the dynamo controller and the actuator to adjust the output of the engine under test. The rate (Sa), the acceleration drive slip rate (Sb) in the acceleration running state, and the deceleration drive slip rate (Sc) in the deceleration running state are calculated and stored in advance as data for correcting the tire slip that occurs when the vehicle is running. For each of the running states, the target engine speed (Rr) Kijosoku driving slip ratio (Sa
), The term obtained by multiplying the acceleration drive slip ratio (Sb) or the deceleration drive slip ratio (Sc) by the target rotation speed (Rr).
(Rta) ｛[Rta = Rr × (1+
Sa)], (Rt b) [Rt b = Rr × (1 + Sb)]
Or (Rt c) [Rt c = Rr × (1 + Sc)]}
Is a new rotational speed after the tire slip correction, respectively, and is used at the time of simulation to control the rotation of the dynamometer.