JP2000314683A - Engine test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine test device which vehicle simulation can be conducted with good accuracy. SOLUTION: A dynamometer 2 connected to an output part 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 which controls revolution of the dynamometer 2, and an actuator which controls valve travel of the throttle of the sample engine 1, are provided. Here, a drive slip rate (y) is calculated as a multidimensional function y=f (Tff) with an output torque (Tff) which is required for an engine and outputted from a torque generator 20 as a parameter, and an engine target number of revolution (Rr) is multiplied by the drive slip factor (y), which is added to the engine target number of revolution (Rr) to provide a number of rotation (Rt)[Rt=Rr×(1+y)], which is taken as a new rotation speed after a wheel slip correction. This is used to control the revolution of the dynamometer 2.

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 FIG. 6A or a target vehicle speed pattern 12b as shown in FIG. That is, the target vehicle speed patterns 12, 12
For a and 12b, the horizontal axis represents time (seconds), and the vertical axis represents speed (km / km).
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. 4 shows a conventional control flow in the engine test apparatus. In FIG.
Is a target pattern generator which is provided in the computer 10 and which is used to drive the test engine 1 in a predetermined traveling pattern based on the target vehicle speed patterns 12 and 12a inputted to the computer 10 so as to drive the actual vehicle. Vr
Is output. This target speed signal Vr is output from the rotation control system 14.
And the simulation 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-described configuration, when the target speed Vr is input to the rotation generator 16, the target rotation speed [dynamometer rotation speed (hereinafter simply referred to as rotation speed) is supplied from the rotation generator 16 based on the target speed Vr. ) Is output.

For example, as shown in FIG.
(A) The target rotation speed Rr set in the target vehicle speed pattern 12a is obtained. In this case, the target vehicle speed pattern 12a
When converting the vehicle speed to the target rotational speed Rr, the tire diameter, the final reduction ratio, and the gear ratio according to the type of the vehicle are taken into consideration.

Then, the target rotation speed Rr becomes a control target rotation speed Rctl via the delay correction circuit 17 and is output to the abutting point 18. Since the actual rotational speed Ra of the dynamometer 2 is input to the abutting point 18, the deviation Re between the control target rotational speed Rctl and the actual rotational speed Ra is, for example, PI-controlled by the rotational feedback controller 19. The operation amount Ud 'is set by
This operation amount Ud 'is sent to the dynamometer 2.

The simulated vehicle control system 15 calculates the target speed V
r, a torque generator 20 to which a target speed Vr is input, and a target speed Vr
Is input in parallel with the speed feedback controller 22. Then, after the torque generator 20 and the speed feedback controller 22, the addition point 23, the butting point 24,
Throttle map 25, throttle opening controller 2
6. A torque control system 27 including the test engine 1 is provided, and 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 required for the engine from the torque generator 20 is output to the addition point 23.

In this case, the target vehicle speed patterns 12, 12
At the time of conversion from a and 12b to feedforward torque Tff, the vehicle inertia weight and running resistance according to the type of vehicle are taken into account.

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.
The operation amount Ua is set, and the operation amount signal Ua is sent to the test engine 1.

Incidentally, since the rotational drive of the engine is transmitted to the tires as it is via the transmission and the differential gear, the actual rotational speed Ra of the dynamometer 2 is effectively controlled by the engine rotational speed. It is considered the same as doing. From this viewpoint, in the engine test apparatus, it is necessary to reproduce the engine rotation during actual vehicle running.

[0017]

In practice, however, slippage occurs between the tires and the road surface when the vehicle is actually running. In the conventional engine test apparatus, this slip was not considered. That is, since the slip cannot be simulated, as shown in FIG. 6, when the actual vehicle is driven on the chassis dynamo and the engine rotation pattern 30 converted from the target vehicle speed pattern 12b in the simulation performed by the conventional engine test apparatus. When the measured engine rotation patterns 31 were compared, a difference occurred between the two. From FIG. 6, the engine rotation pattern 30 is
It can be seen that it shifts below the engine rotation pattern 31 during acceleration and shifts above the engine rotation pattern 31 during deceleration.

In short, in order to reproduce the engine rotation in the actual running of the vehicle, in addition to the tire diameter, the final reduction ratio and the gear ratio, the vehicle inertia weight and the running resistance, the slip between the tire and the road surface is also considered. Although it is necessary, in the conventional engine test apparatus, due to lack of consideration of this point, an 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.

[0020]

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 for controlling the rotation of the dynamometer; and an actuator for controlling a throttle opening of the test engine, wherein a driving slip ratio (y) is output from a torque generator. Polynomial function y with the required output torque (Tff) as a variable
= F (Tff), which is stored. The value is used to correct the engine target rotational speed (Rr), and the dynamometer is rotationally controlled by using the corrected new rotational speed. It is characterized by the following.

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 a real vehicle running on a chassis dynamo, and a rotation control of the dynamometer. In the engine test apparatus provided with a dynamo controller that performs the operation and an actuator that controls the throttle opening of the engine under test, the output torque (Tff) required for the engine, which outputs the drive slip ratio (y) from the torque generator. ) Is used as a variable to calculate a polynomial function y = f (Tff),
A tire slip was corrected for a rotation speed (Rt) [Rt = Rr × (1 + y)] obtained by adding a term obtained by multiplying the engine target rotation speed (Rr) by the drive slip ratio (y) to the engine target rotation speed (Rr). Provided is an engine test apparatus characterized in that the dynamometer is configured to control the rotation by using a new rotation speed later.

The present inventors have found that the engine rotation pattern 30 converted from the target vehicle speed pattern 12b in the conventional simulation shifts up and down from the engine rotation pattern 31 measured on the chassis dynamo due to tire slip. I thought. From this point of view, the concept of a rotation correction rate during actual vehicle running, that is, a drive slip rate y, is introduced. This is because it is defined that the driving slip ratio y during the actual running of the vehicle is determined by the acceleration of the vehicle, that is, as a function of the acceleration of the vehicle, and the acceleration of the vehicle can be simulated by converting it into the output torque of the engine. . That is, the torque supplied from the engine to the tire via the transmission and the differential gear is transmitted to the road surface and becomes a driving force for accelerating the vehicle.

Therefore, the tire slip ratio y is defined as a polynomial function y = f (Tff) using the torque Tff for achieving the target output from the torque generator as a variable.

Then, the present inventors multiply the engine target rotational speed Rr (hereinafter simply referred to as target rotational speed) output from the rotation generator in the simulation by the driving slip ratio y, and obtain the obtained tire slip correction term. (Rr
× y) is added to the target rotational speed Rr to create a new rotational speed Rt 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 Rt after the tire slip has been corrected.
Represents the measured engine rotation pattern 31 as shown in FIG.
, The control computer 10 according to the engine rotation pattern 30 converted from the target rotation speed Rr.
The control computer 10 controls the rotation of the dynamometer 2 according to the engine rotation pattern 40 converted from the new rotation speed Rt after the tire slip has been corrected, as compared with the conventional engine test apparatus that controls the rotation of the dynamometer 2. The engine test apparatus described above can perform a more accurate simulation.

[0027]

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. 4 and 6 among the reference numerals in FIGS.
Are the same as those shown in FIG. 1 and are not described here.

First, FIG. 1 showing a control flow in the engine test apparatus of the present invention is greatly different from FIG. 4 showing a control flow in the conventional engine test apparatus, in that the new rotational speed Rt after the tire slip correction is changed. The dynamometer 2 is configured to be controlled by using the dynamometer 2.

This will be described in more detail with reference to the control flow shown in FIG. 1. In FIG.
This is a tire slip correction means provided between 1 and the delay correction means 17.

The tire slip correcting means 41 calculates the driving slip ratio y from the torque Tff by a function y = f (T
ff), a function of multiplying the target rotational speed Rr output from the rotation generator 16 by the drive slip ratio y, and a tire slip correction term (Rr ×
y) is added to the target rotational speed Rr to calculate a new rotational speed Rt represented by the following equation (1) for controlling the rotation of the dynamometer 2. Rt = Rr × (1 + y) (1)

That is, the drive slip ratio y is defined as a polynomial function y = f (Tff), which is a variable of the output torque (Tff) required for the engine, output from the torque generator 20, and Since (Tff) is patterned as known, the drive slip ratio y can also be patterned.

The target rotational speed Rr of the dynamometer 2
Is also known as a pattern, the target rotational speed R
By multiplying r by the drive slip ratio y, a tire slip correction term (Rr × y) is obtained.

Here, the function y = f (Tff) of the polynomial expression
For example, the following equations (2) and (3) can be adopted. When () y is approximated by a linear expression, y = f (Tff) = A × Tff + B (2) When () y is approximated by a quadratic expression, y = f (Tff) = A × (Tff) ² + B × Tff + C (3) (A, B and C are constants)

Then, in the case of the above (), by substituting the equation (2) into the equation (1), a new target rotation represented by the following equation is obtained: Rt = Rr × [1+ (A × Tff + B)] (4) By controlling the rotation of the dynamometer 2 in accordance with the pattern, it is possible to accurately reproduce the engine rotation during the actual vehicle running in consideration of the slip between the tire and the road surface.

In the case of the above (), the expression (3) is changed to the expression (1).
By substituting into the equation, the rotation of the dynamometer 2 is controlled according to the new target rotation pattern represented by Rt = Rr × [1+ (A × (Tff) ² + B × Tff + C)] (5).

As described above, in the control flow shown in FIG. 1, the tire slip (drive slip) correction means 41 is provided between the point 51 and the delay correction circuit 17, and the torque generator 20 Is input so that a new target rotational speed Rt taking into account the tire slip correction can be obtained, and the rotation of the dynamometer 2 is controlled in accordance with the target rotational speed Rt. In addition, it is possible to accurately reproduce the engine load during actual vehicle running, and to perform a highly accurate simulation.

[0037]

As described above, according to the engine testing apparatus of the present invention, a new target rotation pattern is created in consideration of the slip between the tire and the road surface, and the dynamometer is created in accordance with the new target rotation pattern. , The actual vehicle running can be accurately simulated, and the performance test of the engine can be performed in a more realistic state.

[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. 4 is a diagram showing a control flow in a conventional engine test apparatus.

FIG. 5A is a diagram illustrating an example of a target vehicle speed pattern. (B) is a diagram showing an example of a rotation target pattern.

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 ... Target vehicle speed pattern, 41 ... Tire slip (drive slip) correction means.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuhiro Ogawa 2 Higashi-cho, Kichijoin-gu, Minami-ku, Kyoto, Kyoto F-term (reference) 2G087 BB01 CC01 CC06 DD03 DD09 DD20 EE02 EE22

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 engine test apparatus having an actuator for controlling the throttle opening of an engine, wherein a polynomial expression in which a drive slip ratio (y) is output from a torque generator and an output torque (Tff) required of the engine is used as a variable. Function y
= F (Tff), which is stored. The value is used to correct the engine target rotational speed (Rr), and the dynamometer is rotationally controlled by using the corrected new rotational speed. An engine test apparatus, characterized in that: 2. A dynamometer connected to an output of a test engine which is a test object used to simulate actual vehicle running on a chassis dynamometer, a dynamo controller for controlling rotation of the dynamometer, and An engine test apparatus having an actuator for controlling the throttle opening of an engine, wherein a polynomial expression in which a drive slip ratio (y) is output from a torque generator and an output torque (Tff) required for the engine is used as a variable. Function y
= F (Tff), and the target engine speed (Rr
) Is multiplied by the drive slip ratio (y) and added to the engine target speed (Rr).
t = Rr × (1 + y)] is the new rotational speed after the tire slip correction, and the rotational speed of the dynamometer is controlled by using the new rotational speed.