JPH02151729A - Apparatus for detecting vibration of car body - Google Patents

Abstract

PURPOSE:To judge vibration intensity and vibration frequency by separating low frequency and high frequency even in the case of composite vibration by providing the first and second switching elements turned ON when the vibration of a car body reaches a predetermined value or more to a vibration sensor. CONSTITUTION:A vibration sensor 1 is connected to a car body 3 through a spring 2 and has a light shield plate 5 and a wt. 6 supported by a fulcrum 4. The first photodetector 7 is turned ON when vibration of 0.2G or more in a positive direction is applied from a car body 3 and the second photodetector 8 is turned ON when vibration of -0.2G or more in a negative direction is applied from the car body 8. The first time measuring means 9 measures the ON-time t1 and ON-cycle T2 of the detector 7 and the second time measuring means 10 measures the ON-time t2 of the detector 8 and the ON interval T1 of the detectors 7, 8. The values t1, t2, T1, T2 measured by the means 9, 10 are inputted to a signal processing means 12 and operated to make it possible to know the intensity and frequency of vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle body vibration detection device for detecting vibrations of a vehicle body.

[Conventional technology]

A conventional vehicle body vibration detection device is disclosed in Japanese Patent Application Laid-Open No. 63-8010, for example.
In the former, vehicle body vibration is detected by a vibration sensor, and the integral value of the vehicle body vibration is calculated from the time when the vehicle body vibration exceeds a predetermined value until a predetermined time has elapsed. Vehicle body vibration was determined by or,
In the latter case, the output of the vibration sensor is averaged over a predetermined time period, and the period and intensity of vibration are determined according to this average value.

[Problem to be solved by the invention]

However, in the conventional device described above, an analog linear acceleration sensor using a differential transformer, a piezoelectric element, etc., a vehicle height sensor using a linear or rotary potentiometer, a reed switch, or a photointerrupter are used as vibration sensors. , all of these centimeters were expensive.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a vehicle body vibration detection device that can accurately detect vehicle body vibration using an inexpensive vibration sensor.

[Means to solve the problem]

The vehicle body vibration detection device according to the present invention includes a vibration sensor having first and second switching elements that are turned on when vibration of the vehicle body exceeds a predetermined value in the positive and negative directions, and an on-time period of one of the switching elements. The period, the on time of the other switching element, the on interval time of both switching elements, and the interval time between the final down edge of a series of outputs of one switching element and the first up edge of a series of outputs of the other switching element. The apparatus includes a measuring means and a signal processing means for performing signal processing on the output of the time measuring means and determining the intensity and frequency of vibration.

[For production]

In the vibration sensor of the present invention, the first switching element is turned on when the vehicle body vibration exceeds a predetermined positive value, and the second switching element is turned on when the vehicle body vibration exceeds a predetermined negative value. The 0 time measuring means measures the on time and on period of one switching element, the on time of the other switching element, the on interval time of both switching elements, the final down edge of a series of outputs of one switching element, and the on-period of the other switching element. Measure the interval time between the first up edge of a series of outputs. The signal processing means performs signal processing on the output of the time measuring means and determines the intensity and frequency of the vibration.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of the vehicle body vibration detection device according to this embodiment,
1 is a vibration sensor connected to the vehicle body 3 via a spring 2;
It has a light shielding plate 5 supported by a fulcrum 4 and a weight 6, and is turned on and off by being shielded from light by the light shielding plate 5.
and a second photodetector 7.8. 9,1o
are first and second time measuring means for measuring the time of the outputs of the first and second photodetectors 7.8, and the first time measuring means 9 measures the ON time 1. of the first photodetector. , measure the on-period T2. Second time measuring means 1
0 is the on time of the second photodetector 8, 1. and the on-interval time T of photodetector 7.8 is measured.

The third time measuring means 11 measures the time T3 from the final down edge of one photodetector signal to the first up edge of the other photodetector signal. 12 performs signal processing of the outputs of the time measuring means 9 to 11, and generates vibration G.
This is a signal processing means that determines and outputs the intensity and frequency of the signal.

Next, the operation of the above configuration will be explained. As shown in FIG. 2 (8), the first photodetector 7 turns on when a positive vibration of 0.2 G (G is the acceleration of gravity) or more is applied to the vehicle body 3, and the second photodetector 8 turns on. Figure 2 (b
As shown in 1, it turns on when negative direction vibration of -0.2G or more is applied to the vehicle body 3.

FIG. 3 (al shows the waveform when the vibration of the vehicle body 3 is a single vibration, and FIG. 3 (blicl shows the output waveform of the first and second photodetectors 7.8 at this time.

The first time measuring means 9 measures the on time t and the on period T1 of the first photodetector 8, and the second time measuring means 10 measures the on time t of the second photodetector 8.
2 and the on-interval T of both photodetectors 7.8 is measured. Here, if the vibration frequency is f, it can be found as [= above or "=-2," and Tt 2
T Further, if the vibration waveform is a sine wave, the peak value A in the positive direction will be, and the peak value B in the negative side will be. Also, vibration I! Continuation determination is also possible by comparing T2 and Tz-Tt. Furthermore, the peak value A.

From B, it is possible to determine not only the peak-to-peak vibration intensity variation, but also the offset (compounded low-frequency vibration value) at that time. Therefore, time measuring means 9.1
0 measured tl, L2+T++Tz by signal processing means I
2 and performs the above calculations in the signal processing means 12, it is possible to know the intensity and frequency of the vibration.

Figure 4 rat shows the waveform of the complex vibration that occurs in the vehicle body 3 when the vehicle runs on a undulating gravel road surface, and the output waveform of photodetector 7.8 at this time is shown in Figure 4 (bl
, (shown in C1) In this case, the frequency r of the high frequency component becomes f, -i, and the frequency fl of the low frequency component becomes -1. In the case of a single vibration, 2T+ becomes f, = f. However, in the case of Figure 4, fh)
fz, and it can be easily determined that it is a complex vibration.

Next, intensity determination in the case of complex vibration will be explained with reference to FIGS. 5 and 6. Fig. 5 (al shows the waveform when a low-intensity high-frequency vibration and a large-intensity low-frequency vibration are combined, Fig. 5fb), (cl shows the waveform of the first and second photodetector 7.8 at this time) The output waveform is shown. Fig. 6 ta+ shows the waveform of a complex vibration of a high-frequency vibration with high intensity and a low-frequency vibration with low intensity; 7.8 shows the output waveform. T3 indicates the interval between the final down edge of the output of the first photodetector and the first up edge of the output of the second photodetector 8, and
It is measured by Now, when comparing TI and T3,
If h is relatively large, it is the case of Figure 5, and h is comparative 1.
If the plate is small, it can be determined that the case shown in FIG. 6 is the case.

〔Effect of the invention〕

As described above, according to the present invention, the vibration sensor has a simple configuration including first and second switching elements that are turned on when vehicle body vibration exceeds a predetermined value in the positive and negative directions, and can be made inexpensive. can. Moreover, not only in the case of a single vibration but also in the case of a complex vibration, the vibration intensity and vibration frequency can be determined by separating low and high frequencies, and vehicle body vibration can be detected with high precision.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the device of this invention, Fig. 2 (a), peak) is an output characteristic diagram of the first and second photodetectors according to the invention, and Fig. 3 rat~(C) is a case of single vibration. The vibration waveform diagram and the output waveform diagram of the first and second photodetectors, Figure 4 (8) - (C1 is the vibration waveform diagram in the case of complex vibration and the output waveform diagram of the first and second photodetector,
Figures ta) to tel are vibration waveform diagrams and output waveform diagrams of the first and second photodetectors in the case of composite vibration of low-intensity high-frequency vibrations and high-intensity low-frequency vibrations, and Figure 6 (al~(C1
These are a vibration waveform diagram and an output waveform diagram of the first and second photodetectors in the case of a composite vibration of high-intensity high-frequency vibration and low-intensity low-frequency vibration. l...Vibration sensor, 3...Vehicle body, 7.8...Photograph 1

Claims (1)

[Claims] A vibration sensor having first and second switching elements that turn on when the vibration of the vehicle body exceeds a predetermined value in the positive and negative directions, an on-time and on-period of one switching element, an on-time of the other switching element, a time measuring means for measuring the on interval time of both switching elements and the interval time between the final down edge of a series of outputs of one switching element and the first up edge of a series of outputs of the other switching element; Performs output signal processing,
A vehicle body vibration detection device characterized by comprising a signal processing means for determining the intensity and frequency of vibration.