JP2008134110A - Tracking analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tracking analyzer which is improved in analysis accuracy based on rotational speed information acquired from a communication line for failure diagnosis provided in a vehicle compartment. <P>SOLUTION: This tracking analyzer has: a vibration detection means 1 for detecting vibration generated from a measuring object; a buffer means 4 for storing vibration data outputted from the vibration detection means; a vibration data analysis means 5 for analyzing the vibration data stored in the buffer means; and a rotational speed signal output means 6 for outputting a rotational speed signal from the measuring object. The analyzer has a characteristic wherein an output from the buffer means is synchronized with the rotational speed of the measuring object by delaying a sampling timing relative to analysis processing of the vibration data stored in the buffer means corresponding to a conversion time of a conversion means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tracking analysis apparatus for analyzing a frequency component, a vibration level, and the like of vibration at a specific rotation speed.

  In order to investigate the cause of vehicle vibration and noise, frequency analysis is performed by fast Fourier transform (FFT). At this time, the rotation signal of a rotating body such as a wheel or engine is regarded as a tracking signal, and the vibration is synchronized with this. It is common to analyze the frequency component and vibration level (see Patent Document 1).

  Therefore, in order to increase the analysis accuracy, it is necessary that the reference rotation signal is highly accurate and that it is possible to create a highly accurate sampling timing.

In order to collect such vibration and noise data during actual driving, it is necessary to bring a microphone or accelerometer, a recorder, etc. into the vehicle interior, and it is also necessary to capture wheel or engine rotation signals in the vehicle interior. .
Japanese Patent Publication No. 2-47688

  However, in general mass-produced vehicles for commercial use, the wheel or engine rotation signal is not configured to be taken directly into the passenger compartment, so the signal line is branched from the harness and an amplifier is connected to the signal line. Therefore, it is necessary to consider so as not to hinder the driving of the original vehicle, and the preparation work tends to be troublesome.

  On the other hand, with the spread of computer control, it has become common to provide a communication line coupler (coupler for external diagnostic equipment) under the steering column that can be connected to an external diagnostic equipment for diagnosis when an electronic control device fails. The inventors of the present application have paid attention to the fact that information relating to the rotational speed of the wheel or engine can be obtained from the communication line.

  However, since this rotational speed signal is a result obtained by calculation by an ECU (electronic control unit) based on, for example, a pulse transmitter signal that captures the rotation of the crankshaft, the rotational signal input and rotational speed signal output During this period, the time delay required for the calculation is intervening. Therefore, when this is used for tracking analysis, there is a problem that desired accuracy cannot be obtained.

  The present invention has been devised to eliminate such disadvantages of the prior art, and its main purpose is based on rotational speed information obtained from a communication line for failure diagnosis provided in the passenger compartment. An object of the present invention is to provide a tracking analysis apparatus capable of improving the analysis accuracy.

In order to achieve such an object, claim 1 of the present invention includes a vibration detecting means 1 for detecting vibrations generated by a measured object, a buffer means 4 for storing vibration data output from the vibration detecting means, and the buffer. In a tracking analyzer having vibration data analysis means 5 for analyzing vibration data stored in the means and rotation speed signal output means 6 for outputting a rotation speed signal of the object to be measured, the conversion time of the conversion means Accordingly, the output from the buffer means is synchronized with the rotational speed of the object to be measured by delaying the sampling timing related to the analysis processing of the vibration data stored in the buffer means.
According to a second aspect of the present invention, the rotational speed signal is input from a communication coupler provided in a vehicle interior so as to be connected to a failure diagnosis machine of a vehicle electronic control device.

According to the configuration of the first aspect of the present invention as described above, the frequency component and vibration level data are also obtained even in the driving situation with acceleration / deceleration by delaying the sampling timing of the vibration data by the time required for calculating the rotational speed. Since the synchronization error between the analysis timing and the rotation period is reduced, a great effect can be obtained in improving the analysis accuracy.
According to the second aspect of the present invention, since rotation information is obtained from an existing communication line for an external diagnostic machine provided in the vehicle interior, branching work from a harness and use of an amplifier become unnecessary. This makes it easier to analyze and diagnose vibration and noise at repair shops, and to reduce the amount of extra preparatory work.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram relating to a tracking analysis apparatus to which the present invention is applied. This apparatus includes a detector 1 such as a microphone or an accelerometer that collects a vibration signal including a sound signal, an amplifier 2 that removes noise or adjusts a level from an analog signal collected by the detector 1, and an amplifier 2 A / D converter 3 that converts an analog signal that has passed through a digital signal with a predetermined sampling period (a constant sampling clock), and a buffer memory as a buffer means that temporarily stores the digital signal output from the A / D converter 4, a fast Fourier transformer 5 as vibration data analysis means for analyzing data stored in the buffer memory 4, and a serial communication line 6 as rotation speed signal output means provided with a coupler connected to an external diagnostic machine A rotation speed detector 7 for acquiring a rotation speed signal of the engine or wheels from the serial communication line 6, and a rotation speed It comprises a timing generator 8 that generates sampling timing (synchronized with the rotational speed) when the data stored in the buffer memory 4 is analyzed by the fast Fourier transformer 5 based on the rotational speed signal acquired by the detector 7. ing.

  In this apparatus, the analog data acquired by the detector 1 is stored in the buffer memory 4 together with the time marker as digital data sampled at the first predetermined period, and the rotational speed signal for the diagnostic machine obtained from the serial communication line 6 is stored. A second predetermined period for tracking analysis is generated from the digital data stored in the buffer memory 4 (FIG. 2).

  In this way, the data stored in the buffer memory 4 with the delay corresponding to the time required to convert the rotational speed of the pulse sensor attached to the rotating body such as the crankshaft or the axle to the rotational speed is converted into a fast Fourier transform. By adding to the sampling timing at the time of analysis in 5, accurate tracking analysis can be performed.

  Since the delay time here has a shorter sampling timing cycle as the rotational speed increases, a characteristic that has an inversely proportional relationship to the rotational speed value obtained from the serial communication line should be set in advance. (Fig. 3)

  Note that even if the rotation pulse is directly detected, a slight time delay occurs in order to count the number of pulses per unit time, but the present invention can also be applied to a case where the rotation pulse is directly used for sampling timing.

It is a block diagram which shows the structure of the analyzer to which this invention is applied. It is explanatory drawing which shows the process sequence of this invention. It is a notional characteristic diagram of delay time.

Explanation of symbols

1 Detector 4 Buffer Memory 5 Fourier Transformer 6 Serial Communication Line 8 Timing Generator

Claims (2)

Vibration detecting means for detecting vibrations generated by the measurement object; buffer means for storing vibration data output from the vibration detecting means; vibration data analyzing means for analyzing vibration data stored in the buffer means; A rotational speed signal output means for outputting a rotational speed signal of the measuring body, and a tracking analysis device comprising:
The output from the buffer means is synchronized with the rotation speed of the measured object by delaying the sampling timing related to the analysis processing of the vibration data stored in the buffer means according to the calculation time of the rotational speed of the measured object. A tracking analysis device characterized in that   2. The tracking analysis device according to claim 1, wherein the rotational speed signal is input from a communication coupler provided in a vehicle interior so as to be connected to a failure diagnosis device of a vehicle electronic control device.

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