JPH0337131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration analysis device for a vehicle, and particularly to an improvement in a device for analyzing transient vibrations generated when a vehicle passes a protrusion.

[Prior Art] In order to evaluate the vibration system of a vehicle, protrusions are provided at predetermined intervals on a test course, and the vibrations generated when the vehicle passes these protrusions are analyzed. There is.

An example of such a test course is shown in FIG. It is formed to generate transient vibrations as shown in FIG. 4B. Then, a vibration sensor is provided in the vehicle 14, and the vehicle 1
The characteristics of the vibration system of the vehicle 14 are evaluated by analyzing the transient vibration 100 that occurs when the front and rear wheels of the vehicle 14 pass the protrusion 12 for a predetermined period of time, for example, about 0.2 seconds.

Incidentally, in order to perform such a vibration analysis, it is necessary to apply a trigger signal accurately at the time when the vehicle 14 starts passing the protrusion and to measure the transient phenomenon of the vehicle vibration that occurs.

Conventionally, two types of vibration analyzers are known: one that uses an external trigger signal and one that uses an internal trigger signal.

A vibration analysis device using an external trigger signal requires a detector, such as a photo sensor, to be installed outside the device, such as on the vehicle 14 or the test course 10, to detect when the front or rear wheels of the vehicle 14 pass the protrusion 12. However, there was a problem in that the installation and adjustment of such a detector took time and effort, resulting in poor work efficiency.

In addition, in an analyzer using an internal trigger signal, a predetermined vibration reference level T is set in advance as shown in FIG. It is configured to output a pre-trigger signal when the level T is exceeded.

In FIG. 4, C is the transient vibration 100 shown in B.
is shown enlarged in the time axis direction, and as is clear from the figure, at the time the transient vibration waveform exceeds the reference level T, that is, at the time t ₀ when the pre-trigger signal is output, the transient has already occurred. vibration 100
is understood to have started.

For this reason, such a vibration analyzer always stores data before a predetermined time, and when the pre-trigger signal is output, data t ₁ from a predetermined short period before the trigger signal output time t ₀ is stored. The analysis of the transient vibration 100 is started tracing back to the beginning.

In the embodiment shown in FIG. 4C, the transient vibration occurs for about 0.2 seconds from time _{t1, which is 0.05 seconds before time t0 when} the pre-trigger signal is output, that is, between _t1 and _t2 . We are conducting 100 analyses.

[Problems to be Solved by the Invention] Incidentally, in such an internal trigger type vibration analyzer, in order to accurately output a pre-trigger signal, the reference level T is set to be larger than the maximum value of 200% of the noise vibration. It is necessary to set the value to a value smaller than the maximum value of the transient vibration 100. Therefore, in conventional internal trigger type vibration analyzers, the standard level is set by running the vehicle 14 on a test course 10. was.

However, in conventional vibration analyzers, the standard level was set by a trial-and-error method that relied on the five senses of the person performing the measurement.
It is difficult to accurately set the reference level T by just driving on the top once, and it is necessary to repeat many trial runs to set the reference level.

In particular, noise vibrations 200 and transient vibrations 100 generated when the vehicle 14 runs on the test course 10
The maximum value of T varies depending on the type of vehicle 14 and driving conditions, so with conventional internal trigger type vibration analyzers, it is necessary to repeat trial runs many times to set the reference level T. However, there was a problem in that it took too much time and effort to prepare for vibration analysis.

Purpose of the Invention The present invention has been made in view of such conventional problems, and its purpose is to improve the vibration of a vehicle by making it possible to reliably set a reference level for outputting a pre-trigger signal in a single trial run. Our objective is to provide analytical equipment.

[Means for Solving the Problems] In order to achieve the above object, the device of the present invention includes: a vibration sensor that detects vibrations of a vehicle running on a test course where protrusions are provided at predetermined intervals; A reference level setter that sets a reference level to detect when the vehicle passes a protrusion based on the output, and a pre-trigger signal that compares the output of the vibration sensor with the reference level and outputs a pre-trigger signal when the output of the vibration sensor exceeds the reference level. When the vehicle is running on a test course, the output of the vibration sensor is directed to the reference level setting device, and when the vehicle is actually running on the test course for vibration analysis, the output of the vibration sensor is output to the reference level setting device. a changeover switch that directs and outputs the output of the vibration sensor to a comparator; The vibration analyzer is a vibration analyzer, and the reference level setter includes: a maximum value detection unit that detects the maximum value of vehicle vibration output by the vibration sensor while the vehicle is running on a test course; and a maximum value of the detected vehicle vibration. and a level calculation unit that calculates a value smaller than the maximum value as a reference level based on the value, and is characterized in that the reference level is automatically set when the vehicle runs on a test course once.

In the present invention, the trigger level calculation section includes:
A value obtained by multiplying the maximum vibration level by a reference magnification set in advance to a predetermined value of 1 or less can be output as the reference level.

In addition to this, in the present invention, the maximum value detection section detects the maximum noise vibration value Nmax during normal driving of the vehicle and the maximum transient vibration value Smax when passing a projection based on the output of the vibration sensor, and calculates the level. The section may be formed to calculate the reference level T based on the formula T=1/A(Smax-Nmax)+Nmax using a constant A set in advance to a value larger than 1 and the maximum values Nmax and Nmax. It is possible.

[Example] The present invention consists of the above configuration, and its operation will be explained next.

When a vehicle vibration analysis is to be performed using the apparatus of the present invention, the vehicle 14 is first run on a trial run on the test course 10 shown in FIG. 4A.

At this time, in the present invention, the output of the vibration sensor is inputted to the reference level setter via the changeover switch, and the reference level setter is configured to input the maximum value of vehicle vibration generated when driving on the test course 10. Detect.

Then, based on the detected maximum value of vehicle vibration, the level calculating section automatically calculates a value smaller than this maximum value of vehicle vibration as the reference level T.

In this way, according to the present invention, the reference level T can be automatically set by simply driving the vehicle once on a test course.

After the setting of the reference level T is completed, the vehicle is then driven on a test course for vibration analysis.

At this time, the output of the vibration sensor is input to the comparator via the changeover switch, and the comparator outputs a pre-trigger signal when the output of the vibration sensor V exceeds the reference level T.

When the pre-trigger signal is output, the device of the present invention analyzes the transient vibration of the vehicle output from the vibration sensor for a certain period of time from time t ₁ , which is a predetermined short time before the pre-trigger signal output time t ₀ .

In this manner, according to the present invention, the reference level T can be automatically set by simply running the vehicle on a test course once, and vibration analysis of the vehicle can be quickly and accurately performed. becomes possible.

[Example] Next, a preferred example of the present invention will be described based on the drawings.

First Embodiment FIG. 1 shows a preferred first embodiment of the vehicle vibration analyzer according to the present invention, and the vibration analyzer of the embodiment is mounted on a vehicle 14 shown in FIG. 4A.
The structure is such that vibration analysis can be performed while the vehicle 14 is running on the test course 10.

In an embodiment, this vibration analyzer is installed on a vehicle 14.
The vehicle has a vibration sensor 20 that is attached to the floor surface or the like to detect vehicle vibration, and the detection output of this vibration sensor 20 is input to a changeover switch 22.

The changeover switch 22 switches the vibration sensor 20 when the vehicle 14 is making a trial run on the test course 10.
The output of the vibration sensor 20 is directed to the reference level setter 24, and when the vehicle 14 is actually running on the test course 10 for vibration analysis, the output of the vibration sensor 20 is directed to the comparator 26 and the vibration analyzer 28. Output.

The reference level setter 24 is connected to the vehicle 1.
Based on the signal output from the vibration sensor 20 while the vehicle 14 is making a trial run on the test course 10,
A reference level for detecting the point in time when the object passes over the protrusion 12 is automatically set.

The characteristic feature of the present invention is that when the vehicle 14 runs on the test course 10 once, the maximum value of the noise vibration 200 is greater than the maximum value of the noise vibration 200 after the vehicle 14 normally runs, and the transient vibration 100 at the time of passing the protrusion 12 is
This is because the reference level T can be automatically set to a value smaller than the maximum value of .

For this reason, the reference level setter 24 of the present invention:
A maximum value detection unit 30 detects the maximum value of vehicle vibration output by the vibration sensor 20 while the vehicle 14 is running on the test course 10, and a value smaller than the maximum vehicle vibration value is set as a reference based on this maximum vehicle vibration value. It includes a level calculation unit 32 that calculates the level T.

In the embodiment, the maximum value detection section 30 is formed to hold the maximum value of the vibration waveform during the trial run, that is, the maximum value of the transient vibration 100, as a peak value, and the detected maximum value is used as the level calculation section 32. It is outputting to.

In the embodiment, the level calculation unit 32 includes a magnification setter 36 that sets a reference magnification, and a multiplier 38 that multiplies this reference magnification by the output of the maximum value detection unit 30.
The multiplied value is latched as a reference level T and outputted to the comparator 26.

Here, by setting the reference magnification set by the magnification setting device 36 to a predetermined value of 1 or less, the reference level T is automatically set to a value smaller than the maximum value of the transient vibration 100 and larger than the maximum value of the noise vibration. It is possible to set it to .

In this manner, according to the present invention, it is possible to automatically set the reference level T to an appropriate value by driving the vehicle 14 just once on the test course 10.

Further, after the reference level T is set in this way, when the vehicle 14 is actually driven on the test course 10 in order to perform vibration analysis, the vibration sensor 20
As described above, the outputs are input to the comparator 26 and the vibration analyzer 28 via the changeover switch 22, respectively.

Here, the comparator 26 compares the output V of the vibration sensor 20 with the reference level T output from the level calculation unit 32, and as shown in FIG. 4C, the output V of the vibration sensor 20 exceeds the reference level T. At the same time (at time t ₀ ), a pre-trigger signal is output to the vibration analyzer 28 .

The vibration analyzer 28 performs the following actions during the time from time _{t 1} to t ₂ , which is a predetermined short time (0.05 seconds in the embodiment) before the time t 0 when this pre-trigger signal is output.
The transient vibration 100 output by the vibration sensor 20 is analyzed.

In the embodiment, the vibration analyzer 28 includes a data recording section 40 and a vibration analysis section 42, and the data recording section 40 is formed using a memory that stores the output of the vibration sensor 20 for a certain period of time. .

Furthermore, when the pre-trigger signal is input from the comparator 26, the vibration analysis section 42 detects the transient vibration between t ₁ and t ₂ that is written and stored in the data recording section 40, as shown in FIG. 4C. Perform 100 analyses.

Here, to analyze the vibration waveform, the vibration energy E generated when the vehicle 14 passes over the protrusion 12 is calculated based on, for example, the following equation, and the vibration energy E is analyzed.

E=∫ ^t2 _t1 V ² dt ...(1) In addition to this, for example, if the vehicle 14 hits a protrusion 1
2, that is, between _t1 and _t2, the maximum value of the vibration peak _t0 peak is detected, and the quality of the vibration system is analyzed and evaluated based on this maximum value.

The present embodiment has the above configuration, and its operation will be explained next.

First, in the vibration analyzer of the embodiment, when setting the reference level, the changeover switch 22 is reset to the trial run side, and the test track 10 set for vibration analysis is set as shown in FIG. 4A. The vehicle 14 is made to run on a trial basis.

At this time, the maximum value of vibrations that occur while the vehicle 14 runs on the test course 10, that is, the maximum value of the transient vibration 100, is detected by the maximum value detection section 30, and a predetermined value of 1 or less is detected with respect to this maximum value. The reference level T is automatically calculated by multiplying the value by the set reference magnification.

At this time, by setting the early reference magnification factor to an appropriate value, such as 0.8, taking into account the noise and vibration level during normal driving of the vehicle 14, the vehicle 14 is run on the test course 10 just once. The reference level T can be automatically set to a value larger than the maximum value of the noise vibration 200 and smaller than the maximum value of the transient vibration 100.

After performing a trial run of the vehicle 14 once and setting the reference level T in this way, the selector switch 22 is then set to the actual running side, and the vehicle 14 is actually run on the test course 10 for vibration analysis. let

At this time, from the comparator 26, the vibration sensor 20
Each time the output V exceeds the reference level T, a pre-trigger signal is output, and it is detected that the vehicle 14 has passed over the protrusion 12.

Each time the pre-trigger signal is output in this way, the vibration analyzer 28 detects the transient signal 100 output between _t1 and _t2 , as shown in FIG. 4C.
can be analyzed.

In this way, according to the present embodiment, the reference level can be automatically set to an appropriate value by just one trial run of the vehicle 14 on the test course 10, and preparation for vibration analysis of the vehicle can be performed. can be done quickly.

Second Embodiment FIG. 2 shows a second preferred embodiment of the vibration analyzer according to the present invention. Note that the same reference numerals are given to the members corresponding to those in the first embodiment, and the explanation thereof will be omitted.

In the device of the embodiment, the reference level setter 24
includes a sample waveform hold section 50, a maximum value detection section 30, and a level calculation section 32, and the output of the vibration sensor 20 input via the changeover switch 22 is sequentially sampled and held in the sample waveform hold section 50, and the maximum value is It is output toward the value detection section 30.

The maximum value detection unit 30 determines the maximum value Nmax of the noise vibration 200 and the maximum value Smax of the transient vibration 100 that occur while the vehicle 14 is running on the test course 10 from the sampling hold waveform input in this way. The detection value is output to the level calculation section 32.

T=1/A(Smax-Nmax)+Nmax...(2) In the embodiment, this level calculation section 32
Constant setter 52 that sets the above value as constant A
The arithmetic circuit 54 calculates the reference level T based on the constant A input from the constant setter 52 and Smax and Nmax input from the maximum value detector 30 based on the following equation.

Here, since A is set to a value of 1 or more as described above, the reference level T calculated by the second formula definitely satisfies the following condition, Smax>T>Nmax ...(3 ) The reference level T is the maximum value Nmax of noise vibration 200
It becomes possible to reliably set the value to be larger and smaller than the maximum value Smax of the transient vibration 100.

In addition, in the embodiment, the vibration analyzer 28
has been described using an example in which the data recording section 40 and the vibration analysis section 42 are configured, but the present invention is not limited to this. For example, as shown in FIG. 3, a delay circuit 56 may be used instead of the data recording section 40. , the signal output from the vibration sensor 20 is shown in FIG. 4C (t ₀
-t ₁ ) time and may be input to the vibration analysis section 42. By doing so, the pre-trigger signal is output from the comparator 26, thereby making it possible to automatically analyze the transient vibration 100 between _t1 and _t2 .

[Effects of the Invention] As explained above, according to the present invention, by just one trial run of the vehicle on the test course,
It becomes possible to automatically set the reference level to an appropriate value, and it becomes possible to perform vehicle vibration analysis tests quickly and accurately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first preferred embodiment of the vehicle vibration analysis device according to the present invention, FIG. 2 is a block diagram showing a second preferred embodiment of the present invention, and FIG. 3 is a block diagram showing the present embodiment. 4 is a block diagram showing another embodiment of a vibration analyzer used in the present invention, and FIG.
A is a schematic explanatory diagram of the test course where the vibration analysis test is conducted, B is an explanatory diagram of the vibration waveform that occurs when a vehicle runs on the test course, and C is a transient vibration waveform that occurs when the vehicle passes over a protrusion. FIG. 10...Test course, 12...Protrusion, 14
... Vehicle, 20 ... Vibration sensor, 22 ... Selector switch, 24 ... Reference level setter, 26 ... Comparator, 28 ... Vibration analyzer, 30 ... Maximum value detection section, 32 ... Level calculation 36... Multiplier, 38... Multiplier, 50... Sample waveform holding unit, 52... Constant setter, 54... Arithmetic circuit.

Claims (1)

[Scope of Claims] 1. A vibration sensor that detects vibrations of a vehicle running on a test course where protrusions are provided at predetermined intervals, and a reference level that detects when a vehicle passes the protrusions based on the output of the vibration sensor. A comparator that compares the output of the vibration sensor with the reference level and outputs a pre-trigger signal when the output of the vibration sensor exceeds the reference level, and a comparator that outputs a pre-trigger signal when the vehicle is running on a test course. a changeover switch that directs the output of the vibration sensor to a reference level setter and outputs the output of the vibration sensor to a comparator when the vehicle is actually running on a test course for vibration analysis; A vehicle vibration analysis device that analyzes transient vibrations of a vehicle output by a vibration sensor during a predetermined period of time from a predetermined short time before the output of a pre-trigger signal, the reference level setting device comprising: A maximum value detection unit that detects the maximum value of vehicle vibration output by the vibration sensor during a trial run on a test course, and a level that calculates a value smaller than this maximum value as a reference level based on the maximum value of detected vehicle vibration. 1. A vibration analysis device for a vehicle, comprising: a calculation unit; and automatically setting a reference level when the vehicle runs on a test course once. 2. The device according to claim 1, wherein the level calculation section outputs a multiplication value of a reference magnification set in advance to a predetermined value of 1 or less and a maximum value of vehicle vibration as the reference level. Vibration analyzer. 3. In the device according to claim 1, the maximum value detection section detects the maximum noise vibration value Nmax during normal driving of the vehicle and the maximum transient vibration value Smax when passing a protrusion based on the output of the vibration sensor, and determines the level. The calculation unit is characterized in that it calculates the reference level T based on the calculation formula T=1/A(Smax−Nmax)+Nmax using a constant A set in advance to a value larger than 1 and the maximum values Nmax and Smax. Vehicle vibration analysis equipment.