JP6442316B2 - Wheel speed rotation fluctuation pattern extraction device and its reference pattern setting method - Google Patents

Description

  The present invention relates to a wheel speed rotation fluctuation pattern extraction device that detects a rotation speed fluctuation synchronized with wheel rotation in order to estimate a road surface condition and a tire condition, and a reference pattern setting method thereof. The present invention relates to a technique for accurately correcting an included error.

Conventionally, a speed detection device having a function of correcting a duty ratio and a phase shift in an output signal of a pulse encoder using a correction amount stored in advance has been proposed (for example, Patent Document 2).
Further, a method for estimating a slip ratio and the like from a tire rotation sensor signal is presented, and a method for averaging and detecting a rotation synchronization component from a tire rotation signal over several revolutions is also presented (for example, Patent Document 4). ).

  In addition to this, as shown in FIGS. 13 to 15, a rotation detecting device that outputs a pulse obtained by multiplying the reference signal of the encoder 2 a, and a correction for correcting an error included in the multiplied output by using identification information of the multiplied pulse. The thing provided with the means is shown (for example, patent document 3). FIG. 15 shows the fluctuation of the pulse period before and after the correction.

JP 08-128855 A JP 2002-311040 A JP 2008-249574 A JP 2006-126164 A

  The sensor signal obtained during traveling by the wheel speed sensor includes a signal component specific to the sensor, a signal component due to the drive system (diff or CVJ (constant velocity joint)), and a signal component due to the tire or road surface. It is. The state of the tire can be estimated by analyzing the signal (rotational speed fluctuation) component caused by the tire tread pattern among the signal components caused by the tire and the road surface.

  For this reason, in order to estimate the state of the tire more accurately, it is important to extract the rotational speed fluctuation component caused by the tire tread pattern having a high S / N ratio, and the signal caused by the sensor or the drive system. It is desirable to remove the components.

  It is an object of the present invention to simultaneously correct components caused by a rotation sensor and a drive system, and to extract a rotation speed fluctuation pattern caused by a tire tread pattern having a high S / N ratio. A pattern extraction apparatus and a reference pattern setting method thereof are provided.

The wheel speed rotation variation pattern extraction device of the present invention includes a rotation sensor 2 that detects the rotation speed of the wheel 1 and a signal processing unit 3 that processes a rotation signal output from the rotation sensor 2. A rotation fluctuation pattern extracting means 7 for extracting a rotation speed fluctuation pattern synchronized with the rotation from the rotation signal detected by the rotation sensor 2;
A reference pattern storage memory 9 for storing a reference pattern which is a reference rotational speed variation pattern synchronized with the rotation of the wheel 1 for one rotation;
An error correction processing means 6 for correcting a rotation signal output from the rotation sensor 2 and input to the rotation fluctuation pattern extraction means 7 based on the stored reference pattern;
The reference pattern stored in the reference pattern storage memory 9 was synchronized with the rotation obtained by the rotation sensor 2 using a reference tire which is a tire 1a having no characteristics depending on the rotation position over the entire circumference as the tire of the wheel 1. It is a rotation speed fluctuation pattern.

According to this configuration, the reference pattern generated from the signal running on the reference tire, which is a tire having no features depending on the rotational position over the entire circumference, is stored in the reference pattern storage memory 9 and used as an error correction pattern. The rotation signal output from the rotation sensor 2 and input to the rotation variation pattern extraction means 7 is corrected by the error correction processing means 6. Therefore, components due to the rotation sensor 2 and the drive system can be corrected at the same time, and a rotational speed fluctuation pattern due to a tire tread pattern having a high S / N ratio can be extracted. By analyzing the rotational speed fluctuation component having a high S / N ratio extracted as described above, the state of the tire can be estimated with higher accuracy.
When running with normal tires, the influence of the tread pattern is superimposed on the sensor signal at medium and low speeds. By using the reference tire, a signal that is not affected by the tread pattern of the tire is obtained even when running at medium and low speeds. it can. This makes calibration easier.
The correction is, for example, correction for subtracting a reference pattern from a signal of the rotation sensor 2 that is a wheel speed sensor when the vehicle is running with a normal tire attached. By this correction, it is possible to accurately extract a sensor signal (rotational speed fluctuation) component caused by the tread pattern of the tire that is mounted.

A reference pattern setting method for a wheel speed rotation variation pattern extracting apparatus according to the present invention includes a rotation sensor 2 that detects a rotation speed of a wheel, and a signal processing unit 3 that processes a rotation signal output from the rotation sensor 2. The signal processing unit 3 includes a rotation fluctuation pattern extracting means 7 for extracting a rotation speed fluctuation pattern synchronized with the rotation from the rotation signal detected by the rotation sensor 2, and a reference rotation synchronized with the rotation of the wheel for one rotation. A reference pattern storage memory 9 that stores a reference pattern that is a speed variation pattern, and a rotation signal that is output from the rotation sensor 2 and input to the rotation variation pattern extraction means 7 is corrected by the stored reference pattern. In the wheel speed rotation fluctuation pattern extraction device having the error correction processing means 6, the reference pattern is obtained and the reference pattern is obtained. A method of storing a over emissions storage memory 9,
Using a reference tire, which is a tire with no features depending on the rotation position over the entire circumference, a rotation speed fluctuation pattern synchronized with the rotation is obtained from the rotation signal output from the rotation sensor, and the obtained rotation speed fluctuation pattern is used as the reference pattern. It is stored in the reference pattern storage memory.

According to this method, by running with the reference tire mounted, the signal component due to the tire and road surface other than the signal component due to the tread pattern, the signal component specific to the sensor and the signal component due to the drive system are included. Sensor signals can be acquired simultaneously. Using this, a reference pattern for error correction is created. When running with normal tires, the influence of the tread pattern is superimposed on the sensor signal at medium and low speeds. By using the reference tire, a signal that is not affected by the tread pattern of the tire is obtained even when running at medium and low speeds. it can. This makes calibration easier.
By subtracting the reference pattern from the signal of the wheel speed sensor when running with a normal tire mounted, the sensor signal (rotational speed fluctuation) component resulting from the tread pattern of the tire being mounted is accurately extracted. be able to.
By analyzing the rotational speed fluctuation component having a high S / N ratio extracted as described above, the state of the tire can be estimated with higher accuracy.

In the method of the present invention, the reference tire may be a buffed tire over the entire circumference, depending on the rotational position over the entire circumference as a tire having no irregularities on the tire tread surface, or as a concave portion on the outer circumferential surface. A tire having only a recess having no feature may be used.
Any of these buffed tires, tires that do not have irregularities on the tire tread surface, and tires that have only recesses that are not characterized by the rotational position over the entire circumference, have no characteristics due to the rotational position over the entire circumference. In addition, sensor signals including signal components derived from tires and road surfaces other than signal components derived from tread patterns, signal components unique to sensors, and signal components derived from drive systems can be simultaneously acquired.

In the method of the present invention, in the state where the reference tire is used and the wheel is rotating under an arbitrary speed condition, the period T (1) to T (N) of each rotation pulse during one rotation is set to several rotations, respectively. Measuring and recording over several tens of revolutions;
The average period of each rotation pulse is calculated from the recorded pulse period data for a plurality of rotations, and the obtained data is normalized with an average value to obtain an average period fluctuation pattern for one rotation. Obtaining a reference pattern which is a reference rotational speed variation pattern synchronized with the rotation of the wheel for one rotation,
A process of storing the obtained reference pattern in the reference pattern storage memory 9 may be included.
Thereby, the influence of a random disturbance is suppressed and the appropriate reference pattern of rotation synchronization is obtained.

  The wheel speed rotation fluctuation pattern extracting apparatus of the present invention includes a rotation sensor that detects a rotation speed of a wheel, and a signal processing unit that processes a rotation signal output from the rotation sensor, and the signal processing unit includes the rotation sensor. A rotation speed fluctuation pattern extracting means for extracting a rotation speed fluctuation pattern synchronized with the rotation from the detected rotation signal, and a reference pattern which is a reference rotation speed fluctuation pattern synchronized with the rotation of one rotation of the wheel. A reference pattern storage memory; and an error correction processing unit that corrects a rotation signal output from the rotation sensor and input to the rotation variation pattern extraction unit based on the stored reference pattern. The reference pattern stored in the memory is a tire having no characteristics due to the rotational position over the entire circumference of the wheel tire. Since the rotation speed fluctuation pattern is synchronized with the rotation acquired by the rotation sensor using a reference tire that is a tire, a component caused by the rotation sensor and the drive system can be corrected simultaneously, and the tire has a high S / N ratio. The rotational speed fluctuation pattern resulting from the tread pattern can be extracted.

  According to the reference pattern setting method of the wheel speed rotation fluctuation pattern extraction device of the present invention, the rotation synchronized with the rotation from the rotation signal output from the rotation sensor using the reference tire which is a tire having no feature by the rotation position over the entire circumference. In order to obtain the speed fluctuation pattern and store the obtained rotational speed fluctuation pattern as the reference pattern in the reference pattern storage memory, the signal component due to the tire and road surface other than the signal component due to the tread pattern, the signal specific to the sensor Since the sensor signal including the component and the signal component due to the drive system can be acquired at the same time, and the reference pattern for error correction is created using this, the wheel speed when driving with normal tires attached From the sensor signal, the sensor signal (rotational speed fluctuation) component caused by the tread pattern of the tires It is possible to improve the extraction time.

It is a block diagram which shows the conceptual structure of the wheel speed rotation fluctuation pattern extraction apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the conceptual structure of the example of development which added the tire state estimation unit to the wheel speed rotation fluctuation pattern extraction device. It is an image figure of the signal component contained in the rotation signal detected with the rotation sensor. It is a graph which shows an example of the rotational speed fluctuation pattern in a state without error correction. It is a graph which shows an example of the rotational speed fluctuation pattern when drive | working with the reference | standard tire. It is a graph which shows an example of the rotational speed fluctuation pattern when error correction is carried out with the reference tire. It is a fracture front view of an example of a wheel bearing equipped with a rotation sensor to which the wheel speed rotation variation pattern extracting device is applied. It is the side view of an example which looked at the bearing for the wheels from the inboard side. It is a fracture front view showing other examples of a wheel bearing equipped with the rotation sensor. It is the side view of an example which looked at the bearing for the wheels from the inboard side. It is a fracture | rupture front view which shows the further another example of the wheel bearing equipped with the rotation sensor. It is the side view of an example which looked at the bearing for the wheels from the inboard side. It is the fragmentary sectional view and perspective view which show an example of the rotation sensor to which the same wheel speed rotation fluctuation pattern extracting device is applied. It is the fragmentary sectional view and perspective view which show the other example of the rotation sensor to which the same wheel speed rotation fluctuation pattern extracting device is applied. It is a graph which shows the example of the conventional correction | amendment.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a wheel speed rotation fluctuation pattern extraction device according to an embodiment of the present invention, and FIG. 2 shows a development example in which a tire condition estimation unit is added thereto.

  In FIG. 2, a rotation sensor 2 for detecting the rotation speed of a wheel 1 having a tire 1a that is a target for extracting a rotation speed variation pattern is installed on a wheel bearing or a drive shaft. A signal processing unit 3 for processing a rotation signal output from the rotation sensor 2 is provided. For example, as shown in FIG. 13 or FIG. 14, the rotation sensor 2 includes a magnetic encoder 2 a and a magnetic sensor 2 b, and the magnetic encoder 2 a has N and S magnetic poles 2 aa as detection parts alternately. Instead of the magnetic encoder 2a, a detection gear (not shown) may be used. From the magnetic sensor 2b, a voltage signal in the form of a sine wave or cosine wave is output as a rotation signal that is a rotation speed signal detected by the rotation sensor 2 by the rotation of the magnetic encoder 2a. A specific example of the rotation sensor 2 will be described later.

  The signal processing unit 3 is means for extracting a rotation speed fluctuation pattern synchronized with the rotation from the rotation signal output from the rotation sensor 2. A tire state estimation unit that obtains one or more information of a decrease in the air pressure of the tire 1a, wear of the tire 1a, abnormality in the tread of the tire 1a, and discrimination of the type of the tire 1a using the extracted rotational speed fluctuation pattern. 4 is provided. The rotational speed fluctuation pattern synchronized with the rotation includes information generated by a decrease in tire air pressure, tire wear, tread abnormality, and tire type, and the tire condition estimation unit 4 includes Any of the above information is extracted, and the air pressure drop or the like is estimated from the extracted information.

  The signal processing unit 3 and the tire condition estimation unit 4 constitute an electronic processing device 5. The electronic processing device 5 may be an independent ECU (electronic control unit) or may be provided as a part of an ECU that controls the entire vehicle. In other words, the rotation sensor 2 is a wheel speed sensor. 7 to 12 illustrate wheel bearings with a rotation sensor, which will be described later.

In FIG. 1, the signal processing unit 3 includes an error correction processing unit 6, a rotation variation pattern extraction unit 7, a reference pattern storage memory 9, and a rotation speed determination unit 8.
The rotation fluctuation pattern extraction unit 7 extracts a rotation speed fluctuation pattern synchronized with the rotation from the rotation signal detected by the rotation sensor 2. In this case, the rotation fluctuation pattern extraction means 7 extracts a rotation speed fluctuation pattern synchronized with the rotation from a rotation signal over a plurality of rotations detected by the rotation sensor 2 during traveling. The rotation fluctuation pattern extraction means 7 collects rotation signals for a period of a sufficient number of rotations and averages them in rotation synchronization in order to eliminate the influence of rotation asynchronous disturbance caused by road surface irregularities included in the rotation signals. Alternatively, an integration process is performed to extract a rotationally synchronized speed fluctuation pattern.

  The reference pattern storage memory 9 stores a reference pattern which is a reference rotational speed variation pattern synchronized with the rotation of one wheel. The error correction processing unit 6 corrects the rotation signal output from the rotation sensor 2 and input to the rotation variation pattern extraction unit 7 based on the reference pattern stored in the reference pattern storage memory.

The rotational speed discriminating means 8 uses the rotational signal output from the rotational sensor 2 to measure the rotational speed of the wheel during traveling, and a speed region (for example, 0 to 40 km / h) in which the rotational speed of the wheel (tire) is set. And the rotation signal within the set speed region is extracted. The determination as to whether or not the vehicle is in the set speed region may be made as to whether or not the rotation speed region is equal to or less than a set speed threshold value. The speed threshold is, for example, a wheel rotation speed of 40 km / h. The information on the rotation speed region determined by the rotation speed determination means 8 is used by, for example, the processing by the error correction processing means 6 and the rotation fluctuation pattern extraction means 7, and is output from the signal processing unit to output the lower information processing means (FIG. (Not shown). As the use of the processing by the error correction processing means 6, a sensor-specific component (such as an encoder magnetization error) included in the rotation signal extracted by the rotational speed discrimination means 8, a component caused by the drive system, etc. are corrected ( Remove.
Note that the processing by the rotational speed discriminating means 8 only determines whether or not the rotational speed of the wheel is within the set speed region, and outputs information of the determination result whether or not it is within the speed region,
The processing for extracting the rotation signal in the set speed region may be performed using information that the error correction processing means 6 is in the speed region output from the rotational speed determination means 8.

  The reference pattern stored in the reference pattern storage memory 9 is a rotational speed synchronized with the rotation obtained by the rotation sensor 2 using a reference tire which is a tire having no characteristics depending on the rotation position over the entire circumference as the tire 1a of the wheel 1. Change pattern.

The reference tire may be a tire buffed over the entire circumference, and a tire having no irregularities on the tire tread surface, or a concave portion having no feature depending on the rotational position over the entire circumference as a concave portion on the outer circumferential surface. (For example, a tire having only a longitudinal groove continuous over the entire circumference of the tire).
Any of these buffed tires, tires that do not have irregularities on the tire tread surface, and tires that have only recesses that are not characterized by the rotational position over the entire circumference, have no characteristics due to the rotational position over the entire circumference. In addition, sensor signals including signal components derived from tires and road surfaces other than signal components derived from tread patterns, signal components unique to sensors, and signal components derived from drive systems can be simultaneously acquired.

  The method for obtaining and storing the reference pattern is, for example, the following method. In this method, a cycle T (1) to T (N) of each rotation pulse during one rotation is set to several rotations to several tens of times in a state where the reference tire is used and the wheel 1 rotates at an arbitrary speed condition. The process of measuring and recording over the rotation, and the average period of each rotation pulse is calculated from the recorded pulse period data for multiple rotations, and the obtained data is normalized with the average value to change the average period for one rotation. The process includes obtaining a pattern, obtaining a reference pattern that is the rotationally synchronized speed fluctuation pattern from the average period fluctuation pattern, and storing the obtained reference pattern in the reference pattern storage memory 9.

  The components of the rotation signal shown in FIG. 3 are shown in FIG. 3 by traveling with the reference tire as described above. The signal component attributed to the tire and road surface other than the signal component attributed to the tread pattern, and the signal specific to the sensor Sensor signals including signal components resulting from components and drive systems can be acquired simultaneously. Using this, a reference pattern for error correction is created.

  A sensor signal resulting from the tread pattern of the tire 1a that is mounted by performing a correction that subtracts the reference pattern from the rotation signal of the rotation sensor 2 that is a wheel speed sensor when traveling with the normal tire 1a mounted. The component of the rotation speed fluctuation of (rotation signal) can be extracted with high accuracy. By analyzing the rotational speed fluctuation component having a high S / N ratio extracted as described above, the state of the tire can be estimated with higher accuracy.

  The reference pattern may be created by a computer or the like provided separately from the wheel speed rotation fluctuation pattern extraction device and stored in the reference pattern storage memory 9, or the signal processing unit 3 of the wheel speed rotation fluctuation pattern extraction device. A reference pattern generation unit (not shown) may be provided in the inside, and the reference pattern generation unit may generate the reference pattern generation unit.

Further, the rotation fluctuation pattern extraction means 7 may extract the rotation speed fluctuation pattern using only the rotation signal when it is determined that the vehicle is traveling within the speed region set by the rotation speed determination means 8. .
For example, the rotational speed discriminating means 8 discriminates whether the rotational speed of the wheel is in the set speed area, extracts a rotation signal in the set speed area, and the rotation fluctuation pattern extracting means 7 extracts the rotation thus extracted. A rotational speed fluctuation pattern is extracted using the signal.

  The operation of the above configuration will be described. In the signal processing unit 3 shown in FIG. 1, the rotational speed of the running tire 1a is measured using the rotation signal of the rotation sensor 2, and corrected by the error correction processing means 6 using a reference pattern stored in advance. Processing is performed, and the rotational speed variation pattern synchronized with the rotation of the tire 1 a is extracted by the rotational variation pattern extraction means 7 using the corrected rotational signal. The extracted rotation speed fluctuation pattern is output from the signal processing unit 3.

A detection target such as a magnetic encoder 2a (see FIGS. 13 and 14) used for the rotation sensor 2 that is a wheel speed sensor includes a pitch error unique to the sensor due to manufacturing variations. Therefore, in order to extract rotational speed information with a high S / N ratio, an error included in the magnetic encoder 2a is stored in advance as a reference pattern, and a minute error component superimposed on the rotation signal of the rotation sensor 2 is corrected. There is a need to.
However, since the speed fluctuation component due to the drive system is also superimposed on the running rotation signal, in order to extract the component that depends on the tread of the tire 1a with high accuracy, a reference pattern including these error components is created. There is a need to.

  Tires without lateral grooves (tires having no irregularities on the tire tread surface, tires having only concave portions with no rotation feature on the entire circumference as concave portions on the outer circumferential surface, tires buffed over the entire circumference, etc.) 1a Since the sensor signal (rotation signal) when the vehicle is mounted and traveled does not include a component due to the tread pattern of the tire 1a, a component due to the rotation sensor 2 (encoder 2a) and a component due to the drive system are selected. Extracted. The extracted pattern at this time is stored in the reference pattern storage memory 9 as a reference pattern.

  When correction processing is performed using this reference pattern, components other than the tread pattern of the tire 1a are excluded, a rotational speed fluctuation pattern having a high S / N ratio can be extracted, and the state of the tire 1a being mounted is accurately estimated. be able to

  In the process of extracting the rotational speed fluctuation pattern by the rotational fluctuation pattern extracting means 7, a filter (not shown) such as LPF (low-pass filter or HPF (high-pass filter)) is used to suppress noise components and sensor error components. To extract the components caused by the tire tread pattern from the rotation speed data, which is the rotation signal, and a period over a sufficient number of rotations to eliminate the influence of rotation asynchronous disturbance due to road surface irregularities, etc. The rotation signal is collected and averaged or integrated to extract a specific rotational speed fluctuation pattern.By applying the averaging process and the integration process to the extraction process, random that does not effectively synchronize with the rotation of the tire 1a The effect of the rotational fluctuation is eliminated.

  An actual rotational speed fluctuation pattern is illustrated. FIG. 4 shows a rotational speed fluctuation pattern (Pref) of the drive wheel when a winter tire is mounted as the tire 1a and the vehicle travels on an asphalt road surface. Since the error correction is not performed, all signal components resulting from the rotation sensor 2, the drive system, the tire 1a, and the road surface are included.

  FIG. 5 shows the rotational speed fluctuation pattern (Pstd) of the drive wheels when the reference tire is mounted and the vehicle travels on the asphalt road surface. This includes only the signal components resulting from the rotation sensor 2 and the drive system, the tire (which does not depend on the tread pattern) and the road surface.

  FIG. 6 shows the rotational speed fluctuation pattern (Pcorr) when the rotational speed fluctuation pattern (Pref) of the winter tire is error-corrected with the rotational speed fluctuation pattern (Pstd) of the reference tire. The signal component due to the sensor and the drive system is removed, and only the signal component due to the tread pattern and the road surface of the tire 1a is extracted.

In this way, since the reference (for error correction) pattern generated from the signal running on the reference tire is used, components caused by the rotation sensor 2 and the drive system can be corrected simultaneously, and the tire has a high S / N ratio. The rotational speed fluctuation pattern resulting from the tread pattern can be extracted.
When running with normal tires, the influence of the tread pattern is superimposed on the sensor signal at medium and low speeds, but by using the reference tire, a signal that is not affected by the tread pattern of the tire can be acquired even when running at medium and low speeds. So calibration becomes easy.

  FIG. 13 shows a specific example of the rotation sensor 2. The rotation sensor 2 is a radial type magnetic type, and includes an annular magnetic encoder 2a that is a target, and a magnetic sensor 2b that faces the outer peripheral surface of the magnetic encoder 2a and detects the magnetism of the magnetic encoder 2a. . The magnetic encoder 2a has N and S magnetic poles 2aa alternately, and outputs a sine wave rotation signal from the magnetic sensor 2b. This sinusoidal rotation signal is shaped into a rectangle by the signal processing means 2c and output as a rectangular wave pulse signal. The signal processing means 2c may have a multiplication circuit 2ca, and in that case, outputs a multiplied high-resolution rotation signal.

  The magnetic encoder 2a may include a magnetic pole 2ab for detecting the Z phase (zero phase) in one place on the circumference, aligned in the axial direction with the magnetic pole 2aa. In this case, the magnetic sensor 2b In addition to the sensor unit 2ba for detecting the N and S alternating magnetic poles 2aa, a sensor unit 2bb for detecting the magnetic pole 2ab for detecting the Z phase is provided. This sensor unit 2bb outputs a Z-phase (zero-phase) signal once in one rotation.

  FIG. 14 shows another example of the rotation sensor 2. The rotation sensor 2 is an axial magnetic type, and an annular magnetic encoder 2a and a magnetic sensor 2b face each other in the axial direction. The magnetic encoder 2a is attached to a flange portion of a sensor attachment ring 2d having an L-shaped cross section. Other configurations are the same as those of the radial type rotation sensor 2 shown in FIG. Although not shown in the example of FIG. 14, the radial type rotation sensor 2 may also be provided with a zero-phase magnetic pole, a sensor unit, and a multiplier circuit as described above.

13 and 14 both show the rotation sensor 2 having the magnetic encoder 2a. The rotation sensor 2 is a pulsar ring (not shown) whose target is made of a gear-type magnetic material, a so-called detection gear. May be. In that case, the magnetic sensor detects the teeth of the pulsar ring and outputs a rotation signal.
The magnetic rotation sensor 2 using the magnetic encoder 2a and the gear-type pulsar ring is resistant to inferior environments such as temperature changes and dirt. In the case of the magnetic type, it is difficult to provide the magnetic poles more finely than in the optical type. However, if the multiplication circuit 2ca is provided, a rotation signal having a resolution necessary for detecting the rotation speed fluctuation pattern can be obtained.

  FIGS. 7-12 shows each example of the wheel bearing in which the said rotation sensor 2 is provided. The wheel bearing 30 shown in FIGS. 7 and 8 is a third generation type inner ring rotating type and for driving wheel support, and shows an example in which the rotation sensor 2 is provided in the center of the double row. The wheel bearing 30 includes an outer member 31 having a double row rolling surface 33 formed on the inner periphery, an inner member 32 having a rolling surface 34 opposed to each of the rolling surfaces 33, and these outer members. The rolling member 35 of the double row interposed between the rolling surfaces 33 and 34 of the direction member 31 and the inward member 32 is provided, and a wheel is rotatably supported with respect to a vehicle body. The wheel bearing 30 is a double-row outward angular ball bearing type, and the rolling elements 35 are formed of balls and are held by a cage 36 for each row. The inner member 32 includes a hub wheel 32a and an inner ring 32b fitted to the outer periphery of the inboard side end of the hub wheel 32a. The rolling surface 34 is provided on the outer periphery of each wheel 32a, 32b. . Both ends of the bearing space between the outer member 31 and the inner member 32 are sealed by seals 37 and 38, respectively.

  In the wheel bearing 30, the encoder 2 a of the rotation sensor 2 is provided on the outer periphery between the rolling surfaces 34 of the inner member 32, and the magnetic sensor 2 b facing the encoder 2 a is provided on the outer member 31. It is installed in the provided sensor mounting hole 40 in the radial direction. The rotation sensor 2 is of the radial type described above with reference to FIG.

  The wheel bearing 30 shown in FIG. 9 and FIG. 10 is a third generation type inner ring rotation type and is for driving wheel support, and shows an example in which the rotation sensor 2 is provided at the inboard side end. In this example, the rotation sensor 2 is of the axial type described above with reference to FIG. Specifically, the slinger that is press-fitted and fixed to the outer peripheral surface of the inner member 32 in the seal 38 at the inboard side end also serves as the sensor support ring 2d in the example of FIG. The magnetic sensor 2 b is resin-molded in a ring-shaped metal case 39 and fixed to the outer member 31 via the metal case 39. Other configurations are the same as those of the example shown in FIGS.

  The wheel bearing 30 shown in FIGS. 11 and 12 is a third generation inner ring rotating type and is for supporting a driven wheel, and shows an example in which the rotation sensor 2 is provided at the inboard side end. In this example, the end face opening at the inboard side end portion of the outer member 31 is covered with a cover 29, and the magnetic sensor 2 b of the rotation sensor 2 is attached to the cover 29. Other configurations and operational effects are the same as those of the example shown in FIGS.

DESCRIPTION OF SYMBOLS 1 ... Wheel 1a ... Tire 2 ... Rotation sensor 2a ... Magnetic encoder 2b ... Magnetic sensor 2c ... Multiplication means 3 ... Signal processing unit 5 ... Electronic processing device 6 ... Error correction processing means 7 ... Rotation fluctuation pattern extraction means 9 ... Reference pattern storage memory

Claims (6)

A rotation sensor for detecting the rotation speed of the wheel, and a signal processing unit for processing a rotation signal output from the rotation sensor;
The signal processing unit includes a rotation fluctuation pattern extraction unit that extracts a rotation speed fluctuation pattern synchronized with rotation from the rotation signal detected by the rotation sensor;
A reference pattern storage memory for storing a reference pattern which is a rotation speed variation pattern serving as a reference synchronized with the rotation of the wheel for one rotation;
An error correction processing unit that corrects a rotation signal output from the rotation sensor and input to the rotation variation pattern extraction unit based on the stored reference pattern;
The reference pattern stored in the reference pattern storage memory is a rotational speed fluctuation pattern synchronized with the rotation acquired by the rotation sensor using a reference tire that is a tire having no characteristics depending on the rotational position over the entire circumference as the wheel tire. It is characterized by
Wheel speed rotation fluctuation pattern extraction device. A rotation sensor that detects a rotation speed of the wheel; and a signal processing unit that processes a rotation signal output from the rotation sensor. The signal processing unit is a rotation speed synchronized with the rotation from the rotation signal detected by the rotation sensor. Rotation variation pattern extracting means for extracting a variation pattern, a reference pattern storage memory for storing a reference pattern that is a reference rotational speed variation pattern synchronized with the rotation of the wheel for one rotation, and the stored reference pattern The wheel speed rotation variation pattern extracting apparatus includes an error correction processing unit that corrects a rotation signal output from the rotation sensor and input to the rotation variation pattern extraction unit, and obtains the reference pattern to store the reference pattern. A method of storing in a memory,
Using a reference tire, which is a tire with no features depending on the rotation position over the entire circumference, a rotation speed fluctuation pattern synchronized with the rotation is obtained from the rotation signal output from the rotation sensor, and the obtained rotation speed fluctuation pattern is used as the reference pattern. A reference pattern setting method for a wheel speed rotation variation pattern extracting apparatus, wherein the reference pattern storage memory stores the reference pattern storage memory.   The reference pattern setting method of the wheel speed rotation fluctuation pattern extraction device according to claim 2, wherein the reference tire is a tire buffed over the entire circumference.   The reference pattern setting method of the wheel speed rotation fluctuation pattern extraction device according to claim 2, wherein the reference tire is a tire having no irregularities on a tire tread surface.   3. The reference speed setting method of the wheel speed rotation variation pattern extraction device according to claim 2, wherein the reference tire is a tire having only a concave portion having no feature depending on a rotational position over the entire circumference as a concave portion of the outer peripheral surface. A reference pattern setting method for a rotational fluctuation pattern extraction device. In the reference | standard pattern setting method of the wheel speed rotation fluctuation pattern extraction apparatus of any one of Claim 2 thru | or 5,
Using the reference tire, the period T (1) to T (N) of each rotation pulse during one rotation is several rotations to several tens of rotations in a state where the wheels are rotating at an arbitrary speed condition. The process of measuring and recording,
The average period of each rotation pulse is calculated from the recorded pulse period data for a plurality of rotations, and the obtained data is normalized with an average value to obtain an average period fluctuation pattern for one rotation. Obtaining a reference pattern which is a reference rotational speed variation pattern synchronized with the rotation of the wheel for one rotation,
Storing the determined reference pattern in the reference pattern storage memory,
A reference pattern setting method for a wheel speed rotation variation pattern extraction device.

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