JPH0943107A - Vehicle testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakdown of a vehicle by simultaneously stopping dynamometers by averaging the speeds of the dynamometers and controlling the speeds of the dynamometers in accordance with the difference between a set speed and the average speed when the vehicle is normally operated and, when the vehicle is stopped, generating a decelerating function and controlling the speeds of the dynamometers in accordance with the difference between the output of the function and average speed. SOLUTION: Pulse pickups 14 and 15 detect the rotating speeds of first and second dynamometers as pulses and frequency/voltage converting sections 16 and 17 convert the frequencies of the pulses into voltages. Then an adding section 18 adds the voltages to each other and an amplifier section 19 amplifies the sum of the voltages. When a vehicle is normally operated, the speed of the vehicle is controlled by detecting the difference between the output of a speed setting section 10 and the average of the detected speeds of the two dynamometers by means of a difference detecting section 12 and outputting the difference to the dynamometers as a speed control signal. When the vehicle is stopped due to the detection of abnormality, etc., the speed is controlled in accordance with the difference between a decelerating function generated from a function generating section 22 and the average speed by switching the section 22 through change-over switches 20 and 21. Since the detected speed value is controlled in accordance with the average speed detected by the two dynamometers and difference, the stopping time of the dynamometers becomes the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle testing device using a plurality of dynamometers such as a 4-axis independent chassis dynamometer or a powertrain testing device.

[0002]

2. Description of the Related Art FIG. 4 is a plan view of a four-axis independent chassis dynamometer. 1-4 are rollers for mounting respective wheels of a four-wheel vehicle, 5-8 are dynamometers connected to the rollers 1-4. It is a meter and drives a vehicle in which wheels are mounted on the rollers 1 to 4, and at this time, the dynamometers 5 to 8 absorb the power of rotation of the rollers 1 to 4 to perform a running test of the vehicle.

By the way, the above-mentioned dynamometers 5 to 8
There are two ways to stop the emergency stop: natural stop and natural stop. Fig. 5 shows each dynamometer including emergency stop 5
8 shows a speed control circuit diagram of 8, wherein 9 is a dynamometer rotation detecting section, 10 is a dynamometer speed setting section, 11 is a changeover switch, 12 is a deviation detecting section, and 13 is an amplifying section.
During normal operation, the changeover switch 11 is set to the state shown in the figure, and the deviation between the output of the speed setting section 10 and the output of the rotation detecting section 9 is detected by the deviation detecting section 12, amplified by the amplifying section 13, and used as a current control command for the dynamometer. Output and control the speed of the dynamometer. Changeover switch 1 in case of emergency stop
Switch 1 to the OV side. In this case, the output of the deviation detector 12 becomes negative and the dynamometer is regeneratively braked and stopped.

On the other hand, in the case of the natural stop, the non-controlled state, that is, the current control command is cut off to perform the natural stop.

[0005]

However, since there are a plurality of dynamometers, the capacity of each dynamometer,
Inertia, loss, etc. are different, stop deceleration is different, and stop time is different. For this reason, a large stress is applied to the vehicle and its power train, which may cause damage.

The present invention has been made to solve the above problems, and provides a vehicle test apparatus capable of preventing the damage of a vehicle and its power train by making the stop time of each dynamometer the same. The purpose is to

[0007]

In the vehicle testing apparatus according to the present invention, the speed of each dynamometer is averaged,
The speed of each dynamometer is controlled according to the deviation between the set speed and the average speed during normal operation, and the speed of each dynamometer is controlled based on the deviation between the output of the function generator that generates the function to decelerate and the average speed when stopped. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a speed control circuit diagram of each dynamometer in a vehicle testing device using two dynamometers according to the first embodiment, and 14 and 15 detect the rotation speeds of the first and second dynamometers in pulses. Pulse pickup, 16,
Reference numeral 17 is a frequency-voltage conversion unit that converts the frequency of the pulse into voltage, 18 is an addition unit, 19 is an amplification unit that amplifies to 1/2,
20 and 21 are changeover switches, and 22 is a function generator.

Next, the operation of the above configuration will be described. The rotation speeds of the first and second dynamometers are detected as pulses by the pulse pickups 14 and 15, and the frequencies thereof are converted into voltages by the frequency-voltage conversion units 16 and 17,
The addition section 18 adds the signals, and the amplification section 19 amplifies them to ½. That is, the rotation speeds of the first and second dynamometers are averaged. The changeover switches 20 and 21 are in the illustrated state during normal operation, and the deviation between the output of the speed setting unit 10 and the detected average speed of the two dynamometers is the deviation detection unit 12.
Is detected by the first dynamometer as a speed control signal a or a current control signal, and the second dynamometer is also output as a speed control signal b or a current control signal. Speed controlled.

On the other hand, the changeover switches 20 and 21 are changed over at the time of stoppage such as when an abnormality is detected, and a speed function for decelerating at a predetermined deceleration is generated from the function generator 22. This function and the first and second dynamo A deviation from the average speed of the meter is detected by the deviation detection unit 12, and a speed control signal a, b or a current control signal is sent to the first and second dynamometers in accordance with the deviation, and these are speed controlled. . In this way, the set speed value decreases, the detected speed value becomes the average value of the two dynamometers, and the speed of each dynamometer is controlled by the deviation, so the stop time of each dynamometer is Will be the same.

FIG. 2 shows a circuit diagram of the function generator 22.
3 is a Zener diode, 24 is an integrating circuit, 25 is an amplifying section, 26 is a changeover switch, 27 is a resistance (resistance value R1), and the function generating section 22 has a minimum stop time within a range where each dynamometer is not damaged. So that there is no delay when switching during normal operation. or,
The changeover switch 26 is provided to adjust the deceleration.

According to the first embodiment, the presentation time of each dynamometer is controlled to be the same, and the test vehicle and its power train will not be damaged despite large stress.

Embodiment 2 FIG. 3 shows a speed control circuit diagram of each dynamometer in a vehicle test apparatus using four dynamometers according to Embodiment 2, and reference numerals 14 and 15 detect the rotational speeds of the front and left dynamometers. Pulse pickups, 28 and 29 are pulse pickups that detect the rotational speeds of the left and right dynamometers of the rear wheels, and 16, 17, 30, and 31 convert the frequency of the output of each pulse pickup 14, 15, 28, 29 into a voltage. A frequency-voltage conversion unit, 32 is a frequency-voltage conversion unit 3
The adder 33 that adds the outputs of 0 and 31 is an amplifier that amplifies the output of the adder 32 by half, and the reference 34 is the amplifiers 19 and 33.
And an output of the adder 34 is set to 1
It is an amplifying section that amplifies to / 2.

Next, the operation of the above configuration will be described. The number of revolutions of each dynamometer is determined by the pulse pickup 14,1
5, 28, 29, the frequency of the detected output is converted into a voltage by the frequency-voltage converters 16, 17, 30, 31 and added by the adders 18, 32, and by the amplifiers 19, 33. Amplify to 1/2. Therefore, the output of the amplification section 19 becomes the average speed of the dynamometers on the left and right front wheels, and the output of the amplification section 33 becomes the average speed of the dynamometers on the left and right rear wheels. The adder 34 adds the outputs of the amplifiers 19 and 33, and the amplifier 35 halves the output of the adder 34, so that the output of the amplifier 35 becomes the average speed of all dynamometers.

During normal operation, the changeover switch 2
0 and 21 are in the illustrated state, and the deviation between the output of the speed setting unit 10 and the average speed of all dynamometers is the deviation detector 12
Is detected by the amplifier 13 and the deviation is amplified by the amplifier 13 and is added to each dynamometer as a speed control signal (i) -d or a current control signal to control the speed of each dynamometer. On the other hand, the changeover switches 20 and 21 are changed over at the time of stoppage such as when an abnormality is detected, and the function generating unit 22 generates a decelerating function. The deviation between the function from the function generating section 22 and the average speed from the amplifying section 35 is detected by the deviation detecting section 12, and this deviation is amplified by the amplifying section 13 and sent to each dynamometer to the speed control signal I-D or current. It is output as a control signal, and the speed of each dynamometer is controlled.

Also in the second embodiment, the speed of each dynamometer is controlled according to the deviation between the average speed and the output of the function generator that generates the deceleration function at the time of stop, and the stop time of each dynamometer becomes the same. There is no risk that the vehicle will be damaged due to large stress.

[0017]

As described above, according to the present invention, the speed control of each dynamometer is performed according to the deviation between the output from the function generator that generates the deceleration function at the time of stop and the average speed of each dynamometer. Therefore, the stop time of each dynamometer is almost the same. Therefore, a large stress is not applied to the vehicle or the like, and damage can be prevented.

[Brief description of drawings]

FIG. 1 is a dynamometer speed control circuit diagram in a vehicle testing device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a function generator according to the present invention.

FIG. 3 is a speed control circuit diagram of a dynamometer in a vehicle testing device according to a second embodiment.

FIG. 4 is a plan view of a 4-axis independent chassis dynamometer.

FIG. 5 is a speed control circuit diagram of each dynamometer in the conventional device.

[Explanation of symbols]

 5-8 ... Dynamometer 10 ... Speed setting unit 12 ... Deviation detection unit 14, 15, 28, 29 ... Pulse pickup 18, 32, 34 ... Addition unit 19, 33, 35 ... Amplification unit 20, 21 ... Changeover switch 22 ... Function generator

Claims (1)

[Claims] 1. A vehicle testing apparatus using a plurality of dynamometers, each speed detecting section detecting each speed of each dynamometer, averaging means for averaging outputs of each speed detecting section, and each dynamometer's speed. The speed setting unit for setting the, and a function generating unit that generates a function to decelerate when stopped, while controlling the speed of each dynamometer based on the difference between the output of the speed setting unit and the output of the averaging means during normal operation, A vehicle test apparatus characterized in that the speed of each dynamometer is controlled on the basis of the deviation between the output of the function generating section and the output of the averaging means when the vehicle is stopped.