JPH03295437A - Vehicle vibration test method - Google Patents

Abstract

PURPOSE:To impart a desired motion to axle shafts and a body by detecting the acceleration of two systems of the axle shafts and body independently of each other and using acceleration sensors whose frequencies match the systems respectively. CONSTITUTION:The vehicle attached with various acceleration sensors JS1 - JS4, and BS1 - BS4 is made to actually travel on a rough road, signals obtained by the respective acceleration sensors at this time are gathered by a data decoder 11, and acceleration data and displacement data are generated according to the gathered signals. The axle shaft acceleration sensors JS1 - JS4 have a frequency band of >=3Hz an d the body acceleration sensors have a frequency band of 0.1 - 3Hz. The vehicle to be tested is installed on four exciting machine systems attached with the respective sensors and the systems are driven to perform servo control with the signals from the sensors JS1 - JS4, and BS1 - BS4; and the vehicle is given with the vibration and motion corresponding to the acceleration data and displacement data of the recorder 11 with good reproducibility.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle vibration testing method, and in particular, a method for collecting vibrations applied to a vehicle such as an automobile as actual vibration waveform data when the vehicle is actually driven. A vehicle vibration testing method that allows various vibration tests to be performed without actually driving the vehicle by applying vibration to the vehicle using an electro-hydraulic servo vibration testing machine based on the collected actual vibration waveform data. It is related to.

[Conventional technology]

In order to perform such a vehicle vibration test, it is necessary to have reproducibility of the vibrations applied to the vehicle based on actual vibration waveform data obtained when the vehicle is actually running.

Conventionally, the actual vibration waveform data is collected by actually driving a vehicle on a rough road surface, capturing the motion of the vehicle's axle as an acceleration wave, and recording this on a data recorder.

After that, in the laboratory, a vibration exciter is operated based on this actual vibration waveform data to apply vibration from below the vehicle tires, and the vibration waveform data of the vibration detected at the axle at this time is the same as the above actual vibration waveform data. RPC (
remote parameter control)
The output of the vibrator was controlled using a method.

RP C (Remote Parameter con
trol) method is explained based on Fig. 4.
The vibrator 1 is controlled by a closed loop, and when a signal is input, it tries to operate according to the input signal. In RPC, a signal given from the computer (CPtJ) 2 is given to this closed loop through the DA converter 3. Based on this signal, the data of the measurement point where the vibration result is obtained is outputted and inputted to the CPU 2 through the AD converter 4. The CPU 2 performs processing using this data. The RPC is a waveform control mechanism using a loop that is tied to the outside of the closed loop of the vibrator 1. In the figure, all the vibration exciter control parts are in R
In PC, it is treated as an element. The actual vibration waveform data for simulation is sent to the CPU 2 through the AD converter 4.
Incorporate into. Note that 1°a is a servo valve attached to the vibrator 1, 5 is an acceleration sensor, 6 is a displacement sensor, 7 is a summing point, 8 is an acceleration amplifier, 9 is a displacement amplifier, and 10 is a servo amplifier.

In addition, multi-channel RPC where there are multiple vibrators 1
In this case, in system 2, the number of inputs and outputs of the DA converter and AD converter increases by the number of vibrators, as shown in FIG.

Next, how the above RPC is performed will be explained according to specific operational procedures.

The procedure is roughly divided into four steps, and in the first step, a target waveform is created. That is, a target wave signal from the outside is input, and specifically, as shown in FIG. 6(a), the measurement data stored in the data recorder 11 is input to the CPtJ2 through the AD converter 12, and the external data file 2a is input. Save as. continue,
A target waveform is created, and specifically, as shown in FIG. 6(b), external input data 2a is processed to create a target data file 2b for performing RPC. Processing 7 involves deleting unnecessary parts and cutting frequency components.

In the next second step, the transfer function is measured. Specifically, as shown in Figure 6 (C), excitation is performed using the burst random wave created by CP[J2, and the response is measured. A transfer function is determined from the signal, and a data file 2c is created using the determined transfer function.

In the third step, a correction operation is performed.

That is, the initial control wave is created, and specifically, as shown in FIG. 6(d), the created target data file 2b is
A control waveform data file 2d for the first time of the correction operation is created from the transfer function data file 2c determined as follows. After that, excitation is performed, specifically as shown in Figure 6(e),
Output the created control waveform, excite it, and synchronously input the response measurement signal to create response wave data file 2.
Create e. Next, create a disconnection control waveform. Specifically, as shown in Figure 6, the difference between the response waveform and the target waveform is determined as an error, and the control waveform is corrected using the error signal and the transfer function to create a new control waveform. Create a control waveform data file 2f. The vibration is executed again using the disconnection control waveform obtained here, and a response wave data file is obtained again. Repeat this operation several times to bring the response waveform closer to the target waveform.

In the fourth step, a test is performed, and specifically, as shown in Figure 6 (see Figure 6), the test is performed by excitation using the control waveform obtained by the correction operation in the third step. .

By the way, conventionally, as mentioned above, in order to obtain actual vibration waveform data when the vehicle is actually running, an acceleration sensor is attached to the axle, and all acceleration signals are collected by this acceleration sensor7. Therefore, this acceleration sensor is required to have a measurable upper limit frequency of 1007 or more and to withstand an acceleration level of 50G.

[Problem to be solved by the invention]

However, in an acceleration sensor having the characteristics described above, the acceleration level in the low cycle range is small, and when calculating displacement from this acceleration, integration is performed twice, resulting in a large displacement error. For example, a sine wave of ±10 degrees in 17 is approximately 0.05
G, which is 1/1000 of the acceleration of 50G. Therefore, even if the accuracy of the acceleration sensor is improved, there is an engineering limit to increasing the accuracy of displacement when converted to displacement, and it is practically difficult to reproduce displacements of 2 to 37 or less. is the reality.

By the way, when the actual vehicle is running, the normal motion is for the body to move up and down, roll, and pitch in low cycles, so the motion of the body must also be taken into account for actual wave driving, but as mentioned above, conventionally ~37 or less is difficult to reproduce. On the other hand, sprung mass resonance exists in the range 1 to 27, and if the spectrum around this cannot be reproduced, it will not be possible to perform tests that take body motion into account.

Therefore, in view of the above-mentioned conventional problems, the present invention solves two to three problems.
The object of the present invention is to provide a vehicle vibration testing method capable of reproducing displacements of 7 or less and also reproducing the normal motion that occurs in the body during actual driving of an actual vehicle.

[Means to solve the problem]

In order to solve the above problems, the vehicle vibration testing method according to the present invention focuses on the fact that when the vehicle is actually running, the frequency components of the body motion and the frequency components of the wheel center portion (axle) motion are different. Acceleration data and displacement data are created based on the signals obtained by separately detecting the acceleration applied to each axle of the vehicle and the acceleration applied to the body part corresponding to each axle, and the acceleration applied to each axle is calculated. An electrohydraulic servo vibration system that can independently vibrate each axle of a vehicle equipped with an axle acceleration sensor to detect the acceleration applied to the body part corresponding to each axle. the acceleration data processed by a transfer function of a system mounted on a shaker and including the electro-hydraulic servo exciter and the axle acceleration sensor; and a system including the electro-hydraulic servo exciter and the body acceleration sensor. and the displacement data processed by the transfer function, the vibration exciter is driven using the added data as a target value, and servo control is performed based on signals from the axle acceleration sensor and the body acceleration sensor. It is characterized by

[Function] In the above configuration, when the vehicle is actually running, acceleration data is created based on the signal that detects the acceleration applied to each axle of the vehicle, and at the same time, the acceleration data is generated based on the signal that detects the acceleration applied to each axle of the vehicle. Displacement data is created based on the signals detected respectively.

After that, an axle acceleration sensor that detects the acceleration applied to the axle is attached to each axle of the vehicle, a body acceleration sensor that detects the acceleration applied to the body part is attached to the body part corresponding to each axle, and this axle acceleration sensor and the body A vehicle equipped with an acceleration sensor is placed on an electrohydraulic servo vibrator that can vibrate each axle independently.

Then, the acceleration data is processed by a transfer function of a system including an electro-hydraulic servo exciter and an axle acceleration sensor, and the displacement data is processed by a transfer function of a system including an electro-hydraulic servo exciter and a body acceleration sensor. ,
The processed acceleration data and displacement data are added.

Next, the electro-hydraulic servo exciter is driven using this added data as a target value, and servo control is performed based on signals from the axle acceleration sensor and the body acceleration sensor.

In this way, since the acceleration of the two systems, the axle and the body, is detected independently, it is possible to use an acceleration sensor with frequency characteristics suitable for each prefecture, and based on these independently detected signals, The created acceleration data and displacement data are corrected using the transfer function of each prefecture and then added together, and this added value is used as a target value to drive an electro-hydraulic servo exciter and calculate the output from the axle acceleration sensor and body acceleration sensor. Since servo control is performed based on the signal, desired motion can be imparted to the vehicle body.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a conceptual diagram of a vehicle vibration testing device for carrying out the vehicle vibration testing method according to the present invention.
0. ~204 is acceleration data α1 consisting of a digital signal
~D/A converter that converts α4 to analog signal, 21+
~214 is a transfer function H that corrects the analog acceleration signal
Ml~1 (This is a correction circuit in which 84 is set. Correction circuit 2
1. The transfer function HHI~HHa set to ~214 is
This data was obtained based on the transfer function data obtained using the same method as described above for Fig. 6(C), and is for the entire vibrator system described below, including the vehicle to be vibrated and the axle acceleration sensor. It is. The above acceleration data α,
~ α4 is, as shown in Fig. 2, when the actual vehicle is running.
The vibration acceleration of each axle is detected by the axle acceleration sensors JSI to JS4 attached to each axle, and the data recorder 11 records and collects it on magnetic tape, etc., and it is created based on this collected data. Specifically, it is created in the same manner as described above with respect to FIGS. 6(a) to 6(b). Above axle acceleration sensor JSI~, JS
4 may be any device as long as it can detect acceleration in a frequency band of 3 Hz or higher.

22 to 224 are displacement data D consisting of digital signals;
~D/A converter that converts D4 to analog signal, 23+
~234 is a transfer function HL that corrects the analog displacement signal
This is a correction circuit in which I%HL4 is set. Correction circuit 231
The transfer functions HLI to H14 set to 234 are obtained based on transfer function data obtained in the same manner as the transfer function HMI-HN4, and are obtained based on the transfer function data obtained in the same manner as the transfer function HMI-HN4, and are applied to the vehicle to be vibrated and the vibration exciter described later including the body acceleration sensor. It's about the whole system. As shown in Fig. 2, the above displacement data D, ~D4 are detected by body acceleration sensors BSI~BS4 attached to the body part, which detect the acceleration of the movement of the body part of the vehicle corresponding to each axle during actual driving of the vehicle. However, it is created by recording and collecting it on a magnetic tape or the like in the data recorder 11, and integrating the collected data twice. Specifically, it is created by the same method as in the case of the acceleration signal.

As the body acceleration sensors BSI to BS4, those exclusively used for low frequency range measurement are used. In other words, any material with good acceleration detection ability in the frequency band 0.1 Hz to 3H7 may be used, and the maximum G number G is several Hz to several Hz.
The acceleration value of body B in the low cycle range can be accurately sensed by using a low cycle acceleration sensor having a zero-seven point of several orders of magnitude. This allows displacement data obtained by integrating the output of the body acceleration sensor to be obtained with sufficient accuracy.

The above correction circuit 21. The acceleration signals corrected by the correction circuits 23. to 214 are inputted to the + inputs of the addition points 241 to 244. The displacement signal corrected by 234 is added to the addition point 24. 〜244 single-person power is input, and this additional point is 24. The signals summed in .about.244 are transmitted to the shaker system 25. ~254 are respectively supplied as target signals.

The above vibration exciter system 25. 25. to 254 have substantially the same configuration, one of which is 25. The third section will be explained.

Vibrator system 25. is equipped with a vibrating machine 25b having a servo valve 25a1, and a vibrating table 2 of this vibrating machine 25b.
One wheel of the vehicle is placed on 5a2. An axle acceleration sensor JSl is attached to the axle of the wheel, and a body acceleration sensor BSI is attached to a portion of the body B corresponding to this axle.

The signal supplied to the shaker system 251 is applied to the + input of the first summing point 25c where it is summed with the signal applied to its - human power. A displacement signal obtained by integrating the acceleration signal from the body acceleration sensor BSI twice by an integrating circuit 25d and amplified by a displacement amplifier 25e is applied to the single force of the first addition point 25c.

The signal added at the first addition point 25c is applied to the ten input of the second addition point 25f, where it is added to the signal applied to the -human power.

For the second addition point 25f, the acceleration amplifier 25g
The amplified acceleration signal from the axle acceleration sensor JSI is applied, and the signal added at the second addition point 25f is amplified by the servo amplifier 25h and then applied to the servo valve 25a.

When carrying out the method of the present invention using the vehicle vibration test device having the above-described configuration, first, as shown in FIG. The actual vehicle is driven, and the data decoder 11 collects signals obtained by each acceleration sensor at this time, and generates acceleration data and displacement data based on the collected signals.

On the other hand, axle acceleration sensors JSI to JS4 are attached to each axle of the vehicle to be tested for vibration, and body acceleration sensors BSI to BS4 are attached to body parts corresponding to each axle to detect accelerations applied to the body parts.
Attach each exciter system 25. -'254
is placed on the vibration table 25a2, and the transfer function (lot) is calculated based on the output signals of the axle acceleration sensors JSI to JS4 when vibration is applied using an arbitrary signal and this signal as a target value by the vibration exciter 25b. H□4 is obtained, and the transfer function HLI is obtained using the same method based on an arbitrary signal and the output signals of the body acceleration sensors BSI to BS4 when vibration is applied using the vibrator 25b as a target value.
- Find HL4. Transfer function H) obtained in this way
11-H-4, HL I ``'' HL 4 causes the correction circuit 21. ~214.23. ~234 is set.

Thereafter, the acceleration data and displacement data created as described above are transferred to D/A converters 201 to 2 as shown in FIG.
04. 22I to 224 are respectively converted into analog signals, and the correction circuits 21. ~214. After each correction by 231 to 234, the addition point is 24. 244 and are supplied to the vibrator systems 25I to 254, respectively.

This allows the shaker system 25. ~254, servo control is performed using signals from both the axle acceleration sensors JSI~JS4 and the body acceleration sensors BSI~BS4, and the axle and the body portion corresponding to the axle are controlled according to the acceleration data and displacement data. vibration and motion can be applied with high reproducibility.

In addition, acceleration and displacement are operated in parallel, but this is because the sensing ability of the axle acceleration sensors JSI to JS4 is extremely low when it is 37 or less, and the sensing ability is high when the body acceleration sensor is 37 or less. This is possible because acceleration data and displacement data can be treated independently of each other if the test system is a linear system.

〔effect〕

As explained above, according to the present invention, since the acceleration of the two systems, the axle and the body, is detected independently, it is possible to use an acceleration sensor with a frequency characteristic suitable for each prefecture. Displacements of 37 or less can also be reproduced. In addition, the acceleration data and displacement data created based on signals independently detected while the actual vehicle is running are corrected using the transfer function of each prefecture and then added together. Since the servo control is performed based on signals from the axle acceleration sensor and the body acceleration sensor, it is possible to impart desired motion not only to the axle but also to the body of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an apparatus for carrying out the output vibration test method of the present invention, and Fig. 2 is a method of collecting signals used to create acceleration data and displacement data used in the apparatus of Fig. 1. FIG. 3 is a diagram showing a specific configuration of a part of FIG. 1, and FIGS. 4 to 6 are diagrams for explaining a conventional method using RFC technology. . B...Body, JSI~JS4...Axle acceleration sensor, BSI~BS, 4...Body acceleration sensor,
25b... Vibrator (electro-hydraulic servo vibrator), 21
, ~21. ．． 23. ~234... Correction circuit, 24~2
44... Addition point, 251-254... Vibrator system.

Claims (1)

[Claims] Acceleration data and displacement data are generated based on signals obtained by detecting the acceleration applied to each axle of the vehicle and the acceleration applied to the body part corresponding to each axle when the vehicle is actually running. An axle acceleration sensor that detects the acceleration applied to the axle is attached to each axle, and a body acceleration sensor that detects the acceleration applied to the body part is attached to the body part corresponding to each axle. The acceleration data is mounted on an electro-hydraulic servo exciter that can be vibrated independently, and the acceleration data is corrected by a transfer function of a system including the electro-hydraulic servo exciter and the axle acceleration sensor, and the electro-hydraulic The displacement data corrected by the transfer function of the system including the servo exciter and the body acceleration sensor are added together, and the electro-hydraulic servo exciter is driven using the added data as a target value to calculate the axle acceleration. A vehicle vibration test method characterized in that servo control is performed based on signals from a sensor and a body acceleration sensor.