JP4391353B2 - Apparatus and method for detecting abnormality of rotating body - Google Patents

Description

  The present invention relates to a rotating body abnormality detection apparatus and method for preventing an accident due to a failure of a rotating body (for example, a tire).

  As an apparatus for detecting an abnormality of a rotating body, for example, a tire, an internal pressure abnormality alarm apparatus is known that issues an alarm and warns a driver when the tire internal pressure falls below a certain value. In this apparatus, an internal pressure is measured by an internal pressure sensor attached to a wheel of a tire, and a warning is issued when the pressure falls below a certain internal pressure.

  However, this internal pressure abnormality alarm device cannot detect a failure caused by a cause other than a decrease in internal pressure. For example, as an example of such a failure, separation between the tread and the belt, between the cords constituting the belt, between the side rubber and the carcass ply, breakage of the ply cord or the belt cord, and chunk-out of the tread rubber ( For example, there is a state in which the block land portion provided in the tread is torn off. If the vehicle continues to run in a state where these tire failures occur, a sudden tire burst may occur and the vehicle may become unable to run, and in addition, a serious accident may occur.

As a system for detecting failures other than such internal pressure, an abnormality detection system for a rotating body that knows tire abnormality by measuring tire vibration and sound data and comparing it with normal data obtained in advance is known. (For example, Patent Publication 1). Even with this rotating body abnormality detection system, it is possible to detect a tire abnormality at a sufficient level. However, a rotating body abnormality detection system having a simple configuration and higher performance has been demanded in recent years.
JP 2003-80912 A

  An object of the present invention is to provide an apparatus and a method for detecting an abnormality of a rotating body, in particular, an abnormality detecting apparatus for detecting an abnormality such as a burst of a tire and peeling of a tread at an early stage to prevent an accident. Is.

  The rotating body abnormality detection apparatus of the present invention includes a measuring unit that measures various physical quantities of a rotating rotating body, an extracting unit that extracts a signal synchronized with the rotation of the rotating body from data measured by the measuring unit, and an extracting unit A determination means for determining the state of the rotating body from the signal extracted in step (b), and an abnormality warning means for warning an abnormality when the determination means determines that there is an abnormality. The extraction means includes an adaptive digital filter, In the adaptive digital filter, a signal synchronized with the rotation is extracted, and a signal uncorrelated with the rotation is obtained from the data measured by the measuring means and the signal synchronized with the rotation extracted by the extracting means. It is characterized by optimizing the adaptive digital filter with no signal.

  As a preferred example of the abnormality detection device for a rotating body according to the present invention, various physical quantities of the rotating body measured by the measuring means are vibration, sound, or rotation speed, and a signal synchronized with the rotation is extracted by the extracting means. In using the data obtained by delaying the data measured by the measuring means, the data delay time is a time corresponding to one rotation of the rotating body, and a delay circuit for delaying the data is provided from the measuring means. Comparison between a delay circuit for delaying data and a delay circuit for delaying data to obtain a signal that is not correlated with the rotation of the data input from the measuring means. Have been provided in the signal line to the instrument.

  Furthermore, as another preferred example of the abnormality detection device for a rotating body according to the present invention, when extracting a signal synchronized with rotation by the extraction means, the rotation period is calculated from the rotation information data among the data measured by the measurement means. And the order component generation circuit for generating the order component is provided in the signal line between the rotation information data input unit from the measuring means and the adaptive digital filter. There is.

  Furthermore, as yet another preferred example of the abnormality detection device for a rotating body according to the present invention, in extracting a signal synchronized with rotation by the extracting means, the data measured by the measuring means is selected from the data measured by the measuring means. Variable sampling according to rotational speed information data to make the apparent cycle constant, and a variable sampling circuit for performing variable sampling provided in the data input unit from the measurement means; There is.

  In addition, the abnormality detection method for a rotating body according to the present invention uses the rotating body abnormality detecting device having the above-described configuration to extract and extract a signal synchronized with the rotation of the rotating body from various physical quantities of the rotating rotating body. An abnormality of the rotating body is detected from the signal.

  In the rotating body abnormality detection apparatus and method of the present invention, a signal synchronized with the rotation of the rotating body is extracted by the extracting means from the measured physical quantity such as the measured vibration, sound, or the rotational speed of the ABS, and the abnormality is detected therefrom. By making a determination, abnormalities caused by defects that correlate with the rotation of the rotating body such as a rotating body of the rotating wheel, for example, a burst of a running tire and a tread can be detected at an early stage, and an accident occurs. Can be prevented in advance.

  FIG. 1 is a diagram for explaining an example of a rotating body abnormality detection device of the present invention. In the example shown in FIG. 1, the present invention will be described by taking a tire mounted on a vehicle as an example of a rotating body. However, for the purpose of detecting an abnormality of a rotating body that is rotating, the rotating body other than a tire may be used. It goes without saying that the present invention can be similarly applied.

  In the example shown in FIG. 1, 1 is a tire as a rotating body, 2 is a sensor for measuring vibration or sound attached to each tire 1, and 3 is an abnormality of the tire 1 based on a signal from each sensor 2. Central processing unit. The abnormality detection device for a rotating body of the present invention includes a measuring unit 11 that measures a physical quantity such as vibration or sound by each sensor 2, and an extracting unit 21 that extracts a signal synchronized with the rotation of the tire 1 from data measured by the measuring unit 11. The determination unit 31 determines the state of the tire 1 from the signal extracted by the extraction unit 21 and the abnormality warning unit 41 warns the driver of the abnormality when the determination unit 31 determines that the abnormality is present.

  The measuring means 11 measures sound or vibration around the tire 1 (measured by the sensor 2) or a rotation speed signal such as ABS (sensor 2 is not necessary), and the measured data is output to the extracting means 21 as a digital signal. input. When measuring sound, a microphone or the like is used as the sensor 2. When measuring vibration, an accelerometer, a speedometer, a displacement meter, or the like is used as the sensor 2. In addition, when the vehicle is equipped with an ABS (Anti-lock Brake System), an ABS rotation speed signal can be used. In this case, there is no need to provide the sensor 2, and a simple configuration can be achieved. Besides the ABS, the rotational speed can be measured by another method and the rotational speed signal can be used.

  As the extracting means 21, it is desirable to use means for extracting a periodic component synchronized with the rotation of the tire 1 using an adaptive digital filter. That is, as shown in FIG. 2 as an example of the configuration of the extracting means 21, the extracting means 21 inputs the digital signal X (i) measured by the measuring means 11 and compares it as the input signal (reference signal R (i)). And the signal obtained by delaying the input signal through the delay circuit 22 (directly supplied to the adaptive digital filter 23) is calculated in the adaptive digital filter 23 in real time. A signal correlated with the cycle of the tire 1 is output as the output signal Y (i). Therefore, the output signal Y (i) can be obtained as a signal correlated with the rotation of the tire 1 (periodic signal). The obtained output signal Y (i) is input to the determination means 31.

  The delay time in the delay circuit 22 is preferably set to be equal to or less than the time interval of one rotation of the tire 1, but may be a time interval of two or more rotations, or a time interval having a difference slightly longer than a time of one rotation. There is no problem in obtaining the periodic component synchronized with the rotation by calculation on the characteristics of the adaptive digital filter 23. Further, even when the time interval of one rotation of the tire 1 changes depending on the number of rotations (running speed), it can be dealt with by appropriately setting the sampling frequency and tap length of the adaptive digital filter 23. It can also be realized by previously setting three stages of delay time, low speed, medium speed, and high speed, and changing the delay time of the delay circuit 22 in three stages according to the speed. Of course, it is also conceivable to always measure the speed of the vehicle and change the delay time of the delay circuit 22 in real time according to the speed.

  As the adaptive digital filter 23, a conventionally known configuration can be used. In the example shown in FIG. 2, the reference signal R (i) composed of the digital data X (i) measured by the measuring means 11 and the output Y (i) of the adaptive digital filter are calculated by the comparator 24. A difference between the two is obtained and obtained as an error signal E (i). Therefore, the error signal E (i) can be obtained as a signal (random signal) that is irrelevant to the rotation of the tire 1 and contributes to the road surface or the vehicle body, for example. The obtained error signal E (i) is fed back to the coefficient changing unit of the adaptive digital filter 23, and the coefficient of the adaptive digital filter 23 is dynamically changed in accordance with the error signal E (i). 23 optimization is planned. As a method for optimizing the error signal E (i) by feeding it back to the coefficient changing unit of the adaptive digital filter 23, the LMS (least mean square) method, Newton method, A plunging method can be used.

  As an example of the extracting means 21, as shown in FIG. 2, in addition to the example in which the delay circuit 22 is provided between the input portion of the digital signal X (i) from the measuring means 11 and the adaptive digital filter 23, FIG. As shown in FIG. 2, even if the delay circuit 22 is provided between the input portion of the digital signal X (i) from the measuring means 11 and the comparator 24 and the reference signal R (i) is delayed, it is shown in FIG. The same effect as the present invention can be obtained.

  The judging means 31 uses the value of the output signal Y (i) of the adaptive digital filter 23 of the extracting means 21 to compare with the value of the normal state in each tire 1 or two wheels (front and rear, Left and right) or a method of comparing the values of the four wheels, the tire 1 showing an abnormal value is determined to be abnormal. For this purpose, it is preferable to include a computer having a database section in which data at the time of normality of the tire 1 is recorded, and means for comparing the extracted data of the two wheels or four wheels and determining an abnormality from those differences.

  The abnormality warning unit 41 gives a warning to the driver when the determination unit 31 determines that there is an abnormality. As the abnormality warning means 41, it is preferable to use a warning light or a warning alarm.

  In the abnormality detection device for a rotating body according to the present invention having the above-described configuration, only a signal correlated with the rotation of the tire 1 can be output as an output signal simply and effectively without an accurate tire rotation number signal. It can be extracted as Y (i). That is, only a signal that is correlated with the rotation of the tire 1 such as a burst is included in the output signal Y (i), and a signal that is not correlated with the rotation of the tire 1 in a single event such as climbing to the curb is an output signal. It is not included in Y (i). Therefore, accurate abnormality determination can be performed.

  In the example described above, an example is described in which the vibration and sound signals measured by the sensor 2 are used as the input signal X (i). In addition, the present invention can be similarly applied when an ABS rotation speed signal is used as the input signal X (i). That is, for example, a rotation speed signal composed of a sine wave having a predetermined period includes a signal when the signal is lifted up on a burst and a curb as described above. Even in such a case, the output signal Y (i) including only a signal correlated with the rotation of the tire 1 can be obtained by passing the rotation number signal as the input signal X (i) through the extraction means 21. .

  Next, actual waveforms in the rotating body abnormality detection apparatus of the present invention will be described. As shown in FIGS. 4A and 4B, a vehicle including a front wheel (left) 1-1, a front wheel (right) 1-2, a rear wheel (left) 1-3, and a rear wheel (right) 1-4. Assuming that the burst portion 51 is generated at the shoulder portion of the front wheel (left) 1-1, the input signal X at the initial generation of the burst portion 51 (because the entire tire is damaged over time) (I) Measure the vibration acceleration of each tire signal waveform of the output signal Y (i) and the error signal E (i) with a sensor provided at the knuckle portion of the tire against a good road and a rough road surface. I asked for it.

  FIG. 5 is a diagram showing an example of an input signal X (i), an output signal Y (i), and an error signal E (i) for each tire on a good road, and FIG. 6 is an input signal X for each tire on a rough road surface. It is a figure which shows an example of (i), the output signal Y (i), and the error signal E (i). From the results of FIG. 5 and FIG. 6, as the input signal X (i), a signal correlated with tire rotation (a signal caused by the burst portion) 51 and a signal uncorrelated with tire rotation (road surface unevenness, etc.) Signal), a periodic signal indicating a burst appears only in the output signal Y (i) of the front wheel (left) 1-1 having the burst portion 51, and other normal wheels It can be seen that no signal appears in the output signal Y (i) and the burst can be determined accurately.

  Further, from the result of FIG. 6, there is a signal (a signal caused by a rough road surface) having a larger amplitude than a signal correlated with the rotation of the tire to be measured (a signal caused by the burst unit 51) in the input signal X (i). Even if included, according to the present invention, a periodic signal indicating a burst appears only in the output signal Y (i) of the front wheel (left) 1-1 having the burst portion 51, as in the case of the good road, and the others. It can be seen that no signal appears in the output signals Y (i) of the normal wheels 1-2 to 1-4 and the burst determination can be made accurately. In the example shown in FIGS. 5 and 6, the error signal E (i) is a signal that constantly changes, and the coefficient of the adaptive digital filter 23 is changed according to the change in the signal. It can be seen that the characteristics change accordingly.

  The above-described abnormality detection device for a rotating body of the present invention is an example, and the configuration thereof is not limited to the above-described example. For example, the following configuration can be adopted as a modification of the extraction means 21 shown in FIGS.

  FIG. 7 is a block diagram for explaining another example of the extracting means 21 in the present invention. In the example shown in FIG. 7, the same members as those in the examples shown in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 7, when the component that is not synchronized with the rotation of the tire (the influence of the road surface, the vehicle body, etc.) is larger than the signal that is synchronized with the rotation of the tire, or the component that is synchronized with the rotation of the tire Is small, it can be extracted more accurately by connecting a plurality of digital filters 23 (here, three digital filters 23-1 to 23-3) in series than using one adaptive digital filter 23. it can. That is, in the example shown in FIG. 7, a signal of vibration, sound, or rotation speed is input to the input X (i), and the output Y1 (i) obtained from the filter 23-1 of the first stage (ADF1) is two stages. By repeating the process of inputting to the filter 23-2 of the eye (ADF2), the extraction accuracy can be further improved. There is no limit on the number of filters to be connected.

  8 shows an input signal X (i), an output signal Y (i) (here, three output signals are shown), and an error signal E (i) (here, three error signals are shown) in the extracting means 21 shown in FIG. It is a figure which shows an example. As shown in FIG. 8, the output signal Y (i) has three stages from the first stage output signal Y1 (i) to the second stage output signal Y2 (i) and the second stage output signal Y2 (i). It can be seen that the defect can be extracted more accurately as the output signal Y3 (i) of the eye is obtained.

  FIG. 9 is a block diagram for explaining still another example of the extracting means 21 in the present invention. In the example shown in FIG. 9, the same members as those in the examples shown in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted. As described above, all the periodic signals can be extracted according to the logic (multi-stage etc.) by the adaptive digital filter. However, on the other hand, the signal (( In addition to the periodic signal, when the disturbance is periodic, the influence of the disturbance is extracted. Therefore, as shown in FIG. 9, the order component generation circuit 25 is provided between the input portion of the rotation signal P (i), which is the rotation information from the measuring means 11, and the adaptive digital filter 23, and the rotation information of the rotating body. By generating an order component to be extracted from (for example, rotation information from a wheel speed sensor in the case of a vehicle) and using the adaptive digital filter 23 from the signal, only the component to be extracted can be extracted. The generated order component may be an arbitrary order, and the number is not particularly limited.

  FIGS. 10A and 10B are block diagrams for explaining still another example of the extracting means 21 in the present invention. In the example shown in FIGS. 10A and 10B, the same members as those in the examples shown in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted. In the above-described embodiments shown in FIGS. 2, 3, 7, and 9, the adaptive digital filter 23 may not be sufficiently applied when the rotational speed of the rotating body (vehicle speed in the case of a vehicle) changes. Therefore, as shown in FIGS. 10A and 10B, a variable sampling circuit 26 for performing variable sampling is provided in the data input section from the measuring means, and rotation information of the rotating body (in the case of a vehicle). (ABS wheel speed signal, etc.) is used to change the sampling so that the input signal data has a certain normalized rotation speed (cycle), and the processing in the adaptive digital filter 23 is performed with a constant apparent cycle. By using the logic that enables it, it is possible to sufficiently cope with the speed change of the rotating body.

  In the invention of FIGS. 9 and 10 (a) and 10 (b), this may be a single unit, and a plurality of units may be connected in series. In this case, the extraction accuracy can be further improved. Further, in the example shown in FIG. 10A, the variable sampling circuit 26 is used for the example using the delay circuit 22, and in the example shown in FIG. 10B, the example using the order component generation circuit 25. However, it is also effective for other examples, for example, a combination of adaptive digital filters 23 as shown in FIG. In the example using the order component generation circuit 25 shown in FIG. 10B, the order component is generated by the rotation number (cycle) normalized by the variable sampling circuit 26, and an adaptive filter is used for the signal and the input signal. Thus, only the component to be extracted can be extracted. In FIG. 10A, the delay circuit 22 is arranged between the variable sampling circuit 26 and the determination unit 31, but may be arranged between the variable sampling circuit 26 and the adaptive digital filter 23.

  As another example of the determination means 31, frequency analysis is performed on the output signal Y (i) output from the adaptive digital filter 23, and an arbitrary rotation order component of the rotating body is tracked and extracted from the rotation signal. It is also possible to determine the abnormal time by comparing the result of adding the sizes with the normal time. Furthermore, when the adaptive digital filter 23 provided with the variable sampling circuit 26 is used, since it is normalized with an arbitrary period, the normal time and the abnormal time are compared by adding the frequencies of the fixed arbitrary order components. It becomes possible to do. The order component may be an arbitrary plurality of orders. Further, without performing frequency analysis, a filter of an arbitrary order component may be applied to compare the magnitudes of time signals.

  The rotating body abnormality detection apparatus of the present invention includes a measuring unit that measures various physical quantities of a rotating rotating body, an extracting unit that extracts a signal synchronized with the rotation of the rotating body from data measured by the measuring unit, and an extracting unit Is constituted by a determination means for determining the state of the rotating body from the signal extracted in step (b), and an abnormality warning means for warning the abnormality when the determination means determines that there is an abnormality. In particular, it can be regarded as a periodic signal), and in particular, it can detect abnormalities such as tire bursts and tread peeling at an early stage, and it can be applied to all applications that prevent accidents based on abnormalities in rotating bodies. be able to.

It is a figure for demonstrating an example of the abnormality detection apparatus of the rotary body of this invention. It is a block diagram for demonstrating an example of the extraction means in this invention. It is a block diagram for demonstrating the other example of the extraction means in this invention. (A), (b) is a figure which shows the state of the vehicle at the time of calculating | requiring an actual waveform, respectively. It is a figure which shows an example of the input signal X (i) of each tire on a good road, the output signal Y (i), and the error signal E (i). It is a figure which shows an example of the input signal X (i) of each tire in the rough road surface, the output signal Y (i), and the error signal E (i). It is a block diagram for demonstrating the further another example of the extraction means in this invention. 7 is a diagram illustrating an example of an input signal X (i), an output signal Y (i) (here, 3 output signals are shown), and an error signal E (i) (here, 3 error signals are shown) in the extracting unit shown in FIG. It is. It is a block diagram for demonstrating the further another example of the extraction means in this invention. (A), (b) is a block diagram for demonstrating the further another example of the extraction means in this invention, respectively.

Explanation of symbols

1 Tire 1-1 Front wheel (left)
1-2 Front wheel (right)
1-3 Rear wheel (left)
1-4 Rear wheel (right)
2 Sensor 3 Central processing unit 11 Measuring means 21 Extracting means 22, 22-1, 22-2, 22-3 Delay circuit 23, 23-1, 23-2, 23-3 Adaptive digital filter 24, 24-1, 24 -2, 24-3 Comparator 25 Order component generation circuit 26 Variable sampling circuit 31 Determination means 41 Abnormality warning means 51 Burst section

Claims (11)

  Measuring means for measuring various physical quantities of the rotating rotating body, extracting means for extracting a signal synchronized with the rotation of the rotating body from the data measured by the measuring means, and the state of the rotating body from the signal extracted by the extracting means A determination means for determining, and an abnormality warning means for warning an abnormality when determined to be abnormal by the determination means. The extraction means includes an adaptive digital filter, and the adaptive digital filter outputs a signal synchronized with rotation. Extracting and obtaining a signal uncorrelated with the rotation from the data measured by the measuring means and the signal synchronized with the rotation extracted by the extracting means, and optimizing the adaptive digital filter by the signal not correlated with the obtained rotation An apparatus for detecting an abnormality of a rotating body.   The abnormality detection device for a rotating body according to claim 1, wherein the various physical quantities of the rotating body measured by the measuring means are vibration, sound, or rotation speed.   The abnormality detection device for a rotating body according to claim 1 or 2, wherein data obtained by delaying data measured by the measuring means is used in extracting a signal synchronized with rotation by the extracting means.   4. The rotating body abnormality detection device according to claim 3, wherein the data delay time is a time corresponding to one rotation of the rotating body.   5. The abnormality detection device for a rotating body according to claim 3, wherein a delay circuit for delaying data is provided in a signal line between a data input section from the measuring means and the adaptive digital filter.   5. The rotating body according to claim 3, wherein a delay circuit for delaying data is provided in a signal line between a data input section from the measuring means and a comparator for obtaining a signal having no correlation with rotation. Anomaly detection device.   3. The rotating body according to claim 1, wherein an order component generated by calculating a rotation period from rotation information data among data measured by the measurement means is used when extracting the signal synchronized with rotation by the extraction means. Anomaly detection device.   8. The abnormality detection device for a rotating body according to claim 7, wherein an order component generation circuit for generating an order component is provided in a signal line between an input unit of rotation information data from the measuring means and the adaptive digital filter.   When extracting the signal synchronized with the rotation by the extracting means, the data measured by the measuring means is variably sampled according to the rotational speed information data among the data measured by the measuring means, and the apparent cycle is made constant. The abnormality detection apparatus of the rotary body of any one of Claims 1-8.   The rotating body abnormality detection device according to claim 9, wherein a variable sampling circuit for executing variable sampling is provided in a data input unit from the measuring means. Using the rotating body abnormality detection device according to any one of claims 1 to 10, a signal synchronized with the rotation of the rotating body is extracted from various physical quantities of the rotating rotating body, and the rotating body is extracted from the extracted signal. An abnormality detection method for a rotating body, characterized by detecting an abnormality in the rotating body.

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