WO2015076199A1 - Type recognition device for automobile tires - Google Patents

Abstract

Provided is a type recognition device for automobile tires, capable of detecting information about tire type, during travel, and not requiring a special sensor. The tire type recognition device comprises: a rotation sensor (2) that detects rotation signals from a wheel (1) so as to measure the speed of the automobile; a signal processing unit (3) that extracts fluctuation in rotation speed synchronized to rotation, from the rotation signals detected by this rotation sensor (2), and obtains a rotation speed fluctuation pattern synchronized to the rotation, from the extracted rotation speed fluctuation; a reference pattern storage unit (13) having stored therein either pattern data for rotation speed fluctuation patterns, for each of the plurality of tire (1a) types, or feature parameters related to the tire types; and a tire type determination unit (4) that compares the obtained rotation speed fluctuation pattern to a rotation speed fluctuation pattern recorded in the reference pattern storage unit (13) and estimates the tire (1a) type.

Description

Automotive tire type recognition device Related applications

This application claims the priority of Japanese Patent Application No. 2013-241127 filed on Nov. 21, 2013, which is incorporated herein by reference in its entirety.

The present invention relates to an automobile tire type recognition device that estimates the type of an automobile tire while the automobile is running, and relates to a technology that contributes to a warning about safety and a process of notifying a driver of a difference in tire type.

Patent Document 1 proposes a method of specifying a tire ground contact pattern using an acceleration sensor provided in a rotation mechanism.

Patent Document 2 proposes a method for identifying a tire by obtaining a linear regression coefficient and a correlation coefficient between a tire slip ratio and a vehicle acceleration / deceleration from a measured value of a rotational speed detection device. Yes.

Patent Document 3 proposes a method for calculating the reciprocal of the turning radius and the determination value from the rotation information of the drive wheel, and identifying whether the tire mounted on the drive shaft is a summer tire or a winter tire.

Patent Document 4 proposes a high-resolution rotation detection device provided with a function of multiplying a signal by attaching a rotation detection device to a wheel bearing of an automobile.
Patent Document 5 proposes a rotation detection device capable of detecting an absolute angle by attaching a rotation detection device to a wheel bearing of an automobile.
Patent Document 6 presents a method for estimating a slip ratio and the like from a tire rotation sensor signal, and also presents a method for detecting the rotation synchronization component by averaging the rotation signal of the tire over several rotations.

JP 2006-153832 A Japanese Patent Laid-Open No. 2002-019435 JP 2000-077981 A JP 2011-002357 A JP 2008-232426 A JP 2006-126164 A

If the car tire is a summer tire, it will be easier to slip on a snowy road or a frozen road surface. Moreover, when driving on a dry road surface with a studless tire, ride comfort and driving performance deteriorate.

In order to prevent these, it is recommended that tires be inspected and replaced every season, and that tires suitable for the road surface be fitted. Nevertheless, the driver forgets to temporarily wear a different type of tire (such as an emergency tire) or a studless tire, and the tire type is not appropriate. You may run.

On the other hand, without providing a special sensor, it is possible to detect the type of tire without significantly increasing the cost and to inform the driver that the tire needs to be replaced, which is unsafe. It is desired to prevent accidents caused by running in the state.

An object of the present invention is to provide an automobile tire that can detect information on the type of tire while traveling, does not need a special sensor, and can be mounted on a vehicle without significantly increasing costs. It is to provide a type recognition device.

Hereinafter, in order to facilitate understanding, description will be made with reference to the reference numerals of the embodiments.

A vehicle tire type recognition device according to one configuration of the present invention is configured to rotate from a rotation sensor 2 that detects the rotation of a wheel 1 and a rotation signal detected by the rotation sensor 2 so as to measure the speed of the vehicle. And a signal processing unit 3 for obtaining a rotational speed fluctuation pattern including a rotational speed fluctuation synchronized with the rotation from the extracted rotational speed fluctuation, and a plurality of types of tires 1a. In contrast, the reference pattern storage unit 13 in which the pattern data of the rotational speed variation pattern or the characteristic parameter related to the type of tire is registered, and the acquired rotational speed variation pattern are stored in the reference pattern storage unit 13. Characteristic parameters obtained from registered pattern data or the obtained rotational speed fluctuation pattern are used as the reference pattern. It is compared with a reference pattern consisting of feature parameters registered in the 憶部 13, and a tire type judging unit 4 for estimating (identification) the type of tire 1a.
In addition, the fluctuation | variation of the rotational speed synchronized with rotation arises when the tire 1a rolls on the road surface.

The rotation sensor 2 is installed on a wheel bearing 30 or a drive shaft, and detects the rotation of the wheel 1. The signal processing unit 3 uses the rotation signal detected by the rotation sensor 2 to extract a change in rotational speed synchronized with the rotation of the tire 1a during traveling. The tire type determination unit 4 uses the extracted rotational speed variation pattern as a reference pattern registered in the reference pattern storage unit 13, that is, pattern data of the rotational speed variation pattern, or a characteristic parameter of the tire 1a extracted from the rotational speed variation pattern. And the type of the tire 1a is estimated. The reference pattern storage unit 13 is configured in a database, for example.

Depending on the type of the tire 1a, the shape of the ground contact surface of the tire is different, so the rotational speed variation pattern is also different. That is, this pattern differs depending on the type of the tire 1a, and the type of the tire 1a can be estimated based on the feature. Therefore, the rotational speed fluctuation pattern pattern data or the characteristic parameter extracted from the rotational speed fluctuation pattern is registered in the reference pattern storage unit 13 in advance, and the registered rotational speed fluctuation pattern or characteristic parameter is measured. The type of the tire 1a can be estimated by comparing the acquired rotational speed variation pattern.

Thus, since the information on the type of the tire 1a can be detected during traveling, it is not necessary to provide a special sensor. Therefore, the type recognition function of the tire 1a can be mounted on the vehicle without significantly increasing the cost. Further, even when the driver forgets the type of the tire 1a that is installed, information on what type of tire 1a is installed can be transmitted to the driver, so that preventive safety can be realized. Even if you forget that you are driving in a state where the type of the tire 1a is different from normal, such as when installing an emergency tire, or if the tire 1a suitable for the road surface condition is not installed, the detection signal Since the vehicle can issue a warning based on this, it is possible to prompt the driver to perform a driving operation such as reducing the speed and to prevent a traffic accident.

In the signal processing by the signal processing unit 3, in order to suppress a noise component and a sensor error component, a filter process is performed by a low-pass filter (LPF) or a high-pass filter (HPF), and the tire is generated from the rotation signal as the rotation speed data. You may make it extract the component resulting from the tread pattern of 1a.

In a preferred embodiment, the reference pattern storage unit 13 further stores an initial state or normal rotation speed fluctuation pattern as a reference pattern, and the rotation speed fluctuation pattern detected by the signal processing unit 3 during traveling is stored. When the reference pattern is changed more than a predetermined change reference, the driver outputs inquiry information to the driver regarding a predetermined possibility including after puncture and tire replacement. A reference pattern re-registration unit 23 may be provided for re-registering the rotation speed fluctuation pattern acquired last as the reference pattern in the reference pattern storage unit 13 when the driver permission information is input.
The “case where the change is greater than the predetermined change reference” refers to a case where the displacement is greater than a predetermined amount, and in particular, a case where the rotational speed variation pattern suddenly changes greatly from the reference pattern.

If there is a sudden difference from the reference pattern registered in the initial stage, there is a high possibility that the tire 1a has changed due to replacement, replacement, puncture, or the like. When the tire 1a is replaced, replaced, punctured, etc., the rotational speed variation pattern changes. Therefore, by re-registering the reference pattern to be registered as a new pattern, the tire after replacement etc. The appropriate tire type can be estimated. In addition, re-registration should be done only after inquiring of the driver and obtaining permission from the driver, and re-registration after confirming that the tire has actually been changed. Therefore, it is possible to avoid the re-registration of the reference pattern unexpectedly, and the reliability of the tire type estimation is ensured.

In a preferred embodiment, the signal processing unit 3 subjects the rotation speed fluctuation pattern synchronized with the rotation to a rotation signal over a plurality of rotations of the rotation sensor 2 by performing an averaging process or an integration process synchronized with the rotation, You may get it.
The rotation signal data for one rotation is affected by road surface irregularities, etc., but the rotation signal for a period of a certain number of rotations is collected and averaged or integrated to extract an arbitrary rotation speed fluctuation pattern. Thus, the influence of road surface unevenness is eliminated.
Further, by extracting the rotation synchronization component by integrating or averaging, it is possible to detect a very slight fluctuation in the rotation speed, and therefore it is possible to accurately estimate and notify the tire type.

In a preferred embodiment, the signal processing unit 3 may perform the process of extracting the fluctuation of the rotational speed synchronized with the rotation in a traveling speed range selected from one or more set traveling speed ranges. . Since the occurrence state of the rotational speed changes depending on the state of the tire 1a, it is affected by the traveling speed. That is, the rotational speed fluctuation component exhibits frequency characteristics due to the transmission characteristics of the tire 1a, and its phase and amplitude vary depending on the traveling speed. Therefore, when extracting the rotational speed variation pattern, it is desirable to process using a signal in a state where the rotational speed is in a specific range.

The signal processing unit 3 performs the extraction process for each of a plurality of travel speed ranges, and the tire type determination unit 4 performs a tire type estimation process for each speed range data, and the plurality of estimations. It is good also as a structure which comprehensively judges the kind of tire 1a from the result of a process. By detecting the rotational speed variation pattern in a plurality of speed regions, it is possible to obtain a comprehensive result based on more travel data compared to the case where only one rotational speed region pattern is acquired and determined. Since determination becomes possible, the precision which estimates the kind of tire 1a improves.

In a preferred embodiment, the tire type determination unit 4 determines the tire 1a from the amount of change or correlation between the autocorrelation of the rotational speed variation pattern detected by the signal processing unit 3 and the autocorrelation of the reference rotational variation pattern. The type may be estimated.
Thus, by discriminating from autocorrelation or the like, the type of the tire 1a can be estimated with higher accuracy.

In a preferred embodiment, the rotation sensor 2 is constituted by a rotation sensor 2 having a zero phase or a rotation sensor 2 having an absolute angle detection function, and the signal processing unit 3 determines the phase of the acquired rotation speed fluctuation pattern. In a combined state, a difference between the rotational speed variation pattern and the reference pattern may be obtained, and the tire type may be estimated based on the magnitude of the difference.
By obtaining the difference by matching the phases, the type of the tire 1a can be easily and accurately estimated from the magnitude of the difference.

In a preferred embodiment, the rotation sensor 2 includes a magnetic sensor 2b and a magnetic encoder 2a having a detected pole detected by the magnetic sensor 2b or a pulsar gear, and outputs fluctuations in magnetic strength due to rotation as an analog signal. It is good also as a structure.

If the analog signal output with rotation is analyzed, the fluctuation of the rotation speed can be extracted from the distortion of the waveform included in the signal, so the same processing as in the case of pulse output is possible. Further, the magnetic sensor 2b is preferably a magnetic sensor as the rotation sensor 2 installed in an environment that is more resistant to temperature changes and dirt than the optical sensor and is easily contaminated.

In a preferred embodiment, the rotation sensor 2 outputs a magnetic encoder 2a or a pulser gear having a magnetic sensor 2b and a detected pole detected by the magnetic sensor 2b, and a rotation pulse for multiplying a detection signal of the magnetic sensor 2b. A multiplier circuit 2ca may be provided.

In order to accurately detect a rotational speed fluctuation pattern having a specific fluctuation, which is a detection target, a rotation sensor 2 mounted on the wheel 1 having sufficient detection accuracy and sufficient spatial resolution is used. It is desirable. The rotation sensor 2 that combines the magnetic encoder 2a or the pulser gear and the magnetic sensor 2b as described above, and multiplies the detected magnetic field signal to increase the resolution, is resistant to inferior environments such as temperature changes and dirt, and performs, for example, one rotation. Since it has a rotational resolution of 100 pulses or more, it is suitable for this application.
By combining with the high-resolution rotation sensor 2, the rotational fluctuation component in the low-speed running state can be detected with high resolution, so that the detection accuracy of the type of the tire 1a is increased.

In a preferred embodiment, tire type recognition result utilization means 17 may be provided that performs notification to the driver or change of the control state of the vehicle based on the tire type information estimated by the tire type determination unit 4. . The tire type recognition result utilization means 17 is provided in the computer 16 of the vehicle that is higher than the tire type determination unit 4, for example. Specifically, the tire type determination unit 4 has, for example, one of the following functions.

The tire type recognition result utilization unit 17 may cause the notification unit 19 provided in the driver's seat to be notified based on the information on the type of the tire 1a estimated by the tire type determination unit 4. The notification means 19 is, for example, an image display device 19b such as a liquid crystal display device provided on the console of the driver's seat.
The tire type recognition result utilization means 17 may compare the information of, for example, four-wheel tires 1a and issue a warning when a different type of tire 1a is detected.

The tire type recognition result utilization means 17 changes the control parameter of the vehicle control computer such as the vehicle control ECU 22 based on the information on the type of the tire 1a estimated by the tire type determination unit 4, and according to the type of the tire 1a. It may be a means for performing the predetermined safety control.

For example, the parameters of the safety control system 22a such as vehicle attitude control may be changed according to the detected type of the tire 1a, and the safety control system 22a may be adjusted in consideration of the ability of the tire 1a. In addition, for example, in a state where emergency tires are mounted, the vehicle may be controlled so as to limit the traveling speed to avoid a dangerous state.
Thus, since vehicle control in consideration of the type of the tire 1a is possible, appropriate driving assistance and safety control can be performed according to traveling conditions, and traffic accidents can be prevented.

The tire type recognition result utilization means 17 gives a warning at a predetermined weather based on the information on the type of the tire 1a estimated by the tire type determination unit 4 and the weather during driving obtained from the weather information acquisition means 25. The structure which emits may be sufficient.
Depending on the type of tire 1a that is estimated, a warning is not issued in fine weather, but a warning is issued during rainy weather when slipping is likely to occur. You can call attention.

The tire type recognition result utilization means 17 is configured so that the computer 16 mounted on the vehicle uses the communication line 18 to obtain information on the type of the tire 1a based on the information on the type of the tire 1a estimated by the tire type determination unit 4. It may be a means having a function of transmitting to a terminal of a predetermined sales office 20 capable of inspecting or exchanging tires.
For example, information is transmitted through the vehicle communication line 18 at the same time as the notification by displaying a warning lamp or the like, and the inspection and replacement are promoted through the sales office 20 such as a vehicle dealer or a service store as necessary. To do. Thereby, the inventory check of the tire 1a in the sales office 20 is performed at an early stage, and prompt and appropriate inspection and replacement can be expected.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the present invention.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.
1 is a block diagram showing a conceptual configuration of an automobile tire type recognition device according to a first embodiment of the present invention. FIG. It is a block diagram which shows the conceptual structure of the signal processing unit of the tire type recognition apparatus. It is a block diagram which shows the conceptual structure of the tire type determination unit of the tire type recognition apparatus. It is a block diagram which shows the utilization form of the tire type recognition apparatus. It is a conceptual diagram which shows an example of the preparation method of the rotational speed fluctuation pattern synchronized with the rotation over several rotations. (A) And (B) is explanatory drawing which shows an example of the production method of the rotational speed fluctuation pattern synchronized with the rotation over multiple rotations, and (A) is the rotational speed fluctuation synchronized with the rotation over multiple rotations A pattern is shown, (B) shows the rotational speed fluctuation pattern which averaged these some patterns. Explanatory drawing which shows the conceptual structure of the component which acquires tire information from the rotational speed fluctuation pattern or autocorrelation in the tire type recognition device It is a conceptual diagram which compares the autocorrelation in the tire type recognition apparatus. (A)-(c) is a graph which shows the difference in the rotational speed fluctuation pattern by the difference in a tire type. (A)-(c) is a graph which shows the autocorrelation pattern of the rotational speed fluctuation pattern of various tires. It is sectional drawing of an example of the bearing for wheels equipped with the rotation sensor used with the kind recognition apparatus of the tire. It is the figure which looked at the bearing for the wheels from the inboard. It is sectional drawing of the other example of the wheel bearing equipped with the rotation sensor used with the kind recognition apparatus of the tire. It is the figure which looked at the bearing for the wheels from the inboard. It is sectional drawing of the further another example of the wheel bearing equipped with the rotation sensor used with the kind recognition apparatus of the tire. It is the figure which looked at the bearing for the wheels from the inboard. It is sectional drawing which shows the 1st example of the rotation sensor which the kind recognition apparatus of the tire uses. It is a perspective view of the rotation sensor of FIG. 17A. It is sectional drawing which shows the 2nd example of the rotation sensor which the kind recognition apparatus of the tire uses. FIG. 18B is a perspective view of the rotation sensor of FIG. 18A. It is a block diagram which shows an example of the multiplication circuit in a rotation sensor. It is explanatory drawing of the magnetic sensor using the same multiplication circuit. It is composition explanatory drawing which shows the example of the absolute angle rotation sensor used as the rotation sensor. (A)-(E) are explanatory drawings of the magnetic pole arrangement and detection signals of the rotation sensor. (A)-(E) are explanatory drawings of a magnetic pole arrangement and detection signal processing example of the same rotation sensor.

A tire type recognition device according to a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, this type of automobile tire type recognition device 5 is a rotation sensor 2 for detecting the rotational speed of a wheel 1 having a tire 1a to be type-recognized, and is a wheel bearing or a drive shaft outer ring. And a signal processing unit 3 for processing the output rotation signal. The vehicle tire type recognition device 5 also includes a tire type determination unit 4 that estimates the type of the tire 1 a using the output of the signal processing unit 3.

The signal processing unit 3 is a means for extracting the fluctuation of the rotation speed synchronized with the rotation from the rotation signal detected by the rotation sensor 3 and extracting the rotation speed fluctuation pattern synchronized with the rotation from the extracted fluctuation of the rotation speed. Depending on the type of the tire 1a, the pattern of the ground contact surface of the tire is different, so that the state of occurrence of rotational speed variation is different. This is detected by the tire type determination unit 4 and information on the type of the tire 1a is output. The signal processing unit 3 and the tire type determination unit 4 constitute a type determination device main body 15. The type determination device main body 15 may be an independent ECU, or may be provided as a part of an ECU that controls the entire vehicle. FIG. 11 to FIG. 16 illustrate wheel bearings with rotation sensors, which will be described later.

FIG. 2 shows a conceptual configuration of the signal processing unit 3. In the signal processing unit 3, the rotational speed of the running wheel 1 is measured by the rotational speed discriminating unit 5a using the rotational signal detected by the rotational sensor 2, and the fluctuation of the rotational speed synchronized with the rotation of the wheel 1, that is, one revolution. The rotation fluctuation pattern for each rotation is extracted by the rotation fluctuation pattern extraction unit 6.
Here, a detection target such as a magnetic encoder used for the rotation sensor 2 includes a pitch error due to manufacturing variations. Therefore, the rotation speed fluctuation pattern in the normal state in the initial state is stored in the reference speed pattern storage unit 7 as the reference speed pattern P0, and a minute error component superimposed on the rotation signal of the rotation sensor 2 is corrected for error. The correction is performed by the unit 8.

In the signal processing by the rotation variation pattern extraction unit 6, in order to suppress noise components and sensor error components, filter processing is performed by a low-pass filter (LPF) or a high-pass filter (HPF) (both not shown), Components derived from the shape and tread pattern of the tire 1a are extracted. In addition, in order to eliminate the influence of road surface unevenness, rotation signals for a period of a certain number of rotations are collected and averaged or integrated to extract an arbitrary rotation speed fluctuation pattern. For example, the rotation synchronization component is averaged and detected from the rotation signal of the wheel 1 over several rotations. By applying an averaging process or an integration process to the extraction process, the influence of random rotation fluctuations that are not effectively synchronized with the rotation of the wheel 1 is effectively eliminated.

The extraction of the rotation variation pattern will be described.
Since the occurrence state of the rotational speed changes depending on the state of the tire 1a, it is affected by the traveling speed. That is, the rotational speed fluctuation component exhibits frequency characteristics due to the transmission characteristics of the tire 1a, and its phase and amplitude vary depending on the traveling speed. Therefore, when extracting the rotational speed variation pattern, it is desirable to perform processing using a signal in a state where the rotational speed is in a specific range. The signal processing unit 3 is provided with a rotational speed discriminating unit 5a, so A speed discrimination function is provided.

Preferably, in the rotational speed discrimination process by the rotational speed discriminating unit 5a, the rotational speed fluctuation patterns are classified by a plurality of rotational speed regions (rotational speed levels). That is, a configuration is adopted in which a rotational speed variation pattern is extracted for each rotational speed region, the type of the tire 1a is determined in each region, and a comprehensive determination is made from the result. By detecting the rotational speed variation pattern in a plurality of speed regions, compared to the case of extracting and discriminating only the rotational speed region pattern limited to one, it is comprehensive based on more travel data Since determination becomes possible, the precision which estimates the kind of tire 1a improves.

A specific example of the averaging process will be described with reference to FIGS. 5 and 6A and 6B. In this example, as shown in FIGS. 17A and 17B, the rotation sensor 2 is composed of a magnetic encoder 2a and a magnetic sensor 2b, and the magnetic encoder 2a has N and S magnetic poles 2aa which are detected portions alternately. It is applied when it is a sensor. The same applies to the case of using a pulser gear (not shown) instead of the magnetic encoder 2a as in the case of the magnetic encoder 2a. The rotation sensor 2 will be specifically described later.

As shown in FIG. 5, the output of the rotation sensor 2 is rotated by the rotation speed of the detected portion (the magnetic pole 2aa or the individual teeth of the detection gear) or the required time for the rotation of the tire for one rotation of the tire. An averaging unit 6a of the fluctuation pattern extraction unit 6 averages and a rotation speed fluctuation pattern that becomes tire characteristics is obtained by the extraction unit 6b. Not only taking a simple average but also taking a weighted average that puts more weight on the previous value than the past value, you can always get the latest tire characteristics and follow the tire characteristics over time .

For example, as shown in FIG. 6 (A), when the output of the rotation sensor 2 is given, the passing speed or the passing time of the detected portion (the individual teeth of the magnetic pole 2aa or the detection gear) for a plurality of rotations. When the values are averaged, the rotational speed fluctuation pattern which is the tire characteristic shown in FIG. 6B is obtained. In FIGS. 6A and 6B, the vertical axis represents the passing speed or the time required for passing through each detected part, and the horizontal axis represents the time (corresponding to each detected part).

A method for estimating the tire type (tire type) from the rotational speed variation pattern will be described.
When the type of the tire 1a is changed, the pattern shape of the tire ground contact surface is changed, thereby changing the state of occurrence of the rotational speed fluctuation. This is detected by the tire type determination unit 4 and information relating to the type of the tire 1a is output.

In this case, the tire type determination unit 4 sets a reference for the rotation sensor 2 so that the rotational phase of the traveling speed pattern can be matched, and can detect a change in the rotational speed fluctuation pattern directly. good. The tire type determination unit 4 takes the difference between the detected rotational speed fluctuation pattern and the rotational speed fluctuation pattern as the reference pattern in a state where the rotational phases are matched, and compares the difference with a predetermined threshold value. Alternatively, it may be determined by taking a change amount or correlation between the detected speed fluctuation pattern and the reference rotation speed fluctuation pattern.

In order to facilitate the determination of the rotation phase, a sensor having a Z-phase (zero-phase) signal may be used for the rotation sensor 2, or a resolver or other absolute angle sensor may be used.

As shown in FIG. 7, the tire type determination unit 4 stores, in the reference pattern storage unit 13, a plurality of reference patterns and autocorrelations of tires according to various road surface conditions, and features of each pattern (number and position of peaks, output). Level) is stored, and the type of tire is estimated by comparing with which data the detected rotational speed fluctuation pattern and autocorrelation match. The tire type determination unit 4 includes a reference pattern storage unit 13 including a storage unit that stores reference patterns for a plurality of conditions, and a processing block 4a that compares and searches corresponding patterns from the memory contents of the reference pattern storage unit 13. . In the example of FIG. 7, the reference pattern storage unit 13 has reference patterns for various tire types A, B, C,... For three road surface conditions of dry (Dry), frozen (Ice), and others (Other). It is remembered. The reference pattern storage unit 13 is a database.

If a rotational speed fluctuation pattern that is too different from the reference pattern registered in the initial stage is detected, tire replacement (including low tension) or puncture may be considered, so a warning is issued to the tire type determination unit 4. Warning output means 27 may be provided. The warning output means 27 may be provided as a partial function of the tire type estimation unit 11. Further, the tire type determination unit 4 compares the tire information of the four wheels, and when only one different type of tire is detected, the warning output means 27 or another warning output means (not shown). ) May issue a warning. The outputs of the warning output means 27 are transmitted to a tire type recognition result utilization means 17 provided in the host computer 16 of the vehicle, which will be described later with reference to FIG. 4, and the driver can recognize the tire type recognition result utilization means 17. It outputs to the notification means 19.

If the type of tire that is running is known and a reference pattern corresponding to the road surface is registered in the reference pattern storage unit 13, this method is used to estimate which road surface is close to. Can do.

If the reference pattern data stored in the reference pattern storage unit 13 and the detected rotational speed variation pattern do not match, the tire 1a may have been replaced or some abnormality may have occurred, It can be output. In addition, the state of the traveling road surface can be used by receiving information from the host vehicle computer 16 (FIG. 4). In this case, the condition of the corresponding condition among the reference patterns stored in the reference pattern storage unit 13 is used. It will be compared with the pattern.

A specific example of a method for estimating the tire type by the tire type determination unit 4 will be described.
As shown in FIG. 8, the autocorrelation of the reference pattern is compared with the autocorrelation of the detected rotational speed fluctuation pattern. The autocorrelation pattern shows the characteristics of the tire 1a and has less noise than the rotational speed fluctuation pattern itself, and is therefore suitable for comparison to identify the tire 1a.

In order to evaluate the degree of coincidence, the autocorrelation pattern of the reference pattern is compared with the autocorrelation pattern obtained from the detected rotation signal, and the difference or correlation value between the two is calculated. The sum of squares of the differences may be obtained, and it may be determined that the values match if the value is smaller than a predetermined threshold value. Alternatively, it may be determined that they match when the calculated correlation value exceeds a preset threshold value.
Alternatively, the inner product of the detected autocorrelation of the rotational speed fluctuation pattern and the autocorrelation of the reference pattern may be calculated and judged based on the value.

If an initial rotational speed variation pattern (at the time when there is almost no wear or abnormality immediately after tire replacement) is stored as the reference pattern, an inherent error pattern of the rotation sensor 2, an unbalance of the tire 1a, etc. The amount of change from the initial state including this information can be detected, and the detection sensitivity can be further increased.

When the tire type determination unit 4 detects a pattern having a large deviation from the reference pattern, that is, when the rotational speed variation pattern changes more than the change reference set for the reference pattern, the tire type determination unit 4 When 1a is replaced, warning information is output, and candidate tire types are estimated (identified) with reference to the reference pattern storage unit 13. At the same time, the phase difference from the reference pattern is also investigated, and if the reference pattern shifted in phase matches the detection pattern, it is determined that “the phase has changed when the tire is remounted”. If the phase shift is the wheel nut interval, it is determined that the mounting angle is different. In the case of puncture, it is determined that the tire is not appropriate.

However, if it is determined that the reference pattern has changed, the tire type determination unit 4 presents the detected information to the driver through the vehicle interface (screen display device or the like), and the driver responds to the presented information. When it is confirmed that the current situation is normal because the predetermined input is obtained, it is desirable to update the initial pattern and newly register it. An inquiry to the driver is, for example, a display on the screen such as “Did you change the tire?” Or “Is there any abnormality such as puncture in the right front tire?” Prompt to check the status of

Determination of the candidate tire type, prompting the driver to confirm the state of the tire 1a by presenting information to the driver, and updating and initial registration of the initial pattern by a predetermined input by the driver for the presented information are performed. As a means, the tire type determination unit 4 has a reference pattern re-registration means 23.

In order to accurately detect a rotational speed fluctuation pattern having a specific fluctuation that is a detection target, the rotation sensor 2 mounted on the wheel 1 has sufficient detection accuracy and sufficient spatial resolution. desirable. For example, it has an accuracy capable of detecting at least 0.5% rotation speed variation, and the number of pulses per rotation is 40 or more. In order to acquire sufficient data at the time of low-speed rotation including a higher-order rotation fluctuation component, it is desirable to further increase the resolution of the rotation sensor 2. Considering the structure such as the block size of the tire 1a, it is desirable that the number of output pulses per rotation of the rotation sensor 2 be at least 100 or more so as to ensure a resolution with a contact length of about 20 mm.

Note that the output of the rotation sensor 2 is not necessarily a pulse output, and may be an analog signal. If an analog signal output with rotation is analyzed, fluctuations in the rotation speed can be extracted from the distortion of the waveform included in the signal, so that the same processing as in the case of pulse output is possible. In particular, when the resolution (multiplication capability) of the rotation pulse is low, it is desirable to execute signal processing with high resolution by actively using analog signals.

The example of the data tested about the kind of several tire 1a is demonstrated.
Rotational speed data was collected at a resolution of 960 times per revolution by changing the type of tire 1a. If the type of the tire 1a is different, the force acting on the tire contact surface changes due to the difference in the shape of the tire contact surface, the flexibility of the rubber, etc., and the rotational speed variation pattern also changes. FIGS. 9A to 9C show the rotational speed fluctuation patterns of the summer tire, the studless tire, and the sports tire, respectively.
It can be seen that the rotational speed variation pattern changes depending on the type of the tire 1a.

FIGS. 10A to 10C show autocorrelation patterns of rotational speed fluctuation patterns of summer tires, studless tires, and sports tires, respectively. The characteristics of each tire appear in the autocorrelation pattern. Since the same autocorrelation pattern is obtained for the same type of tire, the tire type can be estimated.

A method of using the estimated type information of the tire 1a will be described with reference to FIG.
As shown in the figure, tire type recognition result utilization means 17 is provided for informing the driver or changing the control state of the vehicle based on the tire type information estimated by the tire type determination unit 4. The tire type recognition result utilization means 17 is provided in the computer 16 of the vehicle that is higher than the tire type determination unit 4, for example. Specifically, the tire type determination unit 4 has, for example, one of the following functions.

Information on the detected tire type is transmitted from the signal processing unit 3 (FIG. 1) to the host computer 16 (FIG. 4) of the vehicle, and the tire type recognition result utilization means 17 determines the tire type (summer, studless, etc. Depending on the type, etc., a lamp or the like is turned on to display information on the type of tire that is mounted to the driver.

Further, when only one of the estimated types of tires 1a is different, or when a tire suitable for the road surface condition during traveling is not worn, the tire type recognition result utilization means 17 Notification by the notification means 19, for example, lighting of a display lamp 19a such as a warning lamp or display of a caution display by an image display device 19b such as a liquid crystal display device is performed to prompt the driver to check or replace the tire 1a.

At the same time, the tire type recognition result utilization means 17 transmits information through the vehicle communication line 18, and if necessary, adjustment and inspection are promoted through the sales office 20 such as a vehicle dealer or a service store.

In addition, depending on the type of tire 1a being detected, a warning is not issued when the weather is fine, but a warning is issued during driving during snowfall or rain. It can also be urged. For example, the tire type recognition result utilization unit 17 warns at the time of a predetermined weather based on the information on the type of the tire 1 a estimated by the tire type determination unit 4 and the weather during traveling obtained from the weather information acquisition unit 25. To emit. If it is determined that the state is particularly dangerous, a function of automatically limiting the traveling speed may be provided. The weather information acquisition means 25 is a means for obtaining input from a radio, television, or other weather information communication means mounted on the vehicle, or a sensor (not shown) for detecting the weather.

Further, the parameters of the safety control system 22a such as the vehicle attitude control provided in the vehicle control computer such as the vehicle control ECU 22 that controls the operation of the vehicle are changed according to the detected type of the tire 1a, and the capability of the tire 1a is changed. The safety control system 22a may be adjusted in consideration of the above.

The effects of the tire type recognition device according to the above embodiment are summarized below.
-Since the information on the type of the tire 1a can be detected during traveling, it is not necessary to provide a special sensor. Therefore, it can be mounted on a vehicle without significantly increasing the cost.
Even when the driver forgets the type of the tire 1a that is installed, information on what type of tire 1a is installed can be transmitted to the driver, so that preventive safety can be realized.
-Even when the driver forgets that the driver is forgetting that the type of the tire 1a is not appropriate, such as when an emergency tire is mounted, or when the tire 1a suitable for the road surface condition is not mounted. Since the vehicle can issue a warning by the detection signal, it is possible to perform a driving operation such as reducing the speed and to prevent a traffic accident.
-Since vehicle control in consideration of the type of tire 1a is possible, appropriate driving assistance and safety control can be performed according to driving conditions, and traffic accidents can be prevented.
-By integrating and averaging and extracting the rotation synchronization component, it is possible to detect a rotation fluctuation pattern having a very slight fluctuation, so that the type of the tire 1a can be accurately detected and notified.
-By combining with the rotation sensor 2 having a higher resolution, the rotational fluctuation component in the low-speed traveling state can be detected with a high resolution, so that the detection accuracy of the type of the tire 1a is increased.

FIGS. 17A and 17B show a first 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.

18A and 18B show a second 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 FIGS. 17A and 17B. Although not shown in the examples of FIGS. 18A and 18B, the radial type rotation sensor 2 may also be provided with a zero-phase magnetic pole and a sensor unit, and a multiplier circuit as described above.

17A and 17B and FIGS. 18A and 18B all show the rotation sensor 2 having the magnetic encoder 2a. The rotation sensor 2 is a so-called pulsar ring (not shown) whose target is made of a gear-type magnetic material. It may be a detection gear. 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.

FIG. 19 shows an example of the multiplier circuit 2ca. As shown in FIG. 20, the multiplication circuit 2ca has a phase difference of 90 degrees (λ / 4) when the pitch λ of one magnetic pole pair of the magnetic encoder 2ba is one cycle, as shown in FIG. Using two magnetic sensor elements 2baa and 2bab such as Hall elements arranged apart from each other in the arrangement direction of the magnetic poles, a phase in the magnetic pole ( The calculation is made by multiplying φ = tan-1 (sinφ / cos φ)).

As shown in FIG. 19, this multiplication circuit 2ca includes a signal generating means 41, a fan-shaped detecting means 42, a multiplexer means 43, and a fine interpolation means 44.

The signal generating means 41 has the same amplitude A0 and the same average value C0 from the two-phase signals sinφ and cosφ which are the outputs of the magnetic sensor elements 2baa and 2bab of the magnetic sensor 2b, and m is n The following positive integer, i is a means for generating 2 ^m-1 signals si having phases shifted by 2π / 2 ^{m-1 from} each other, where i is a positive integer of 1 to 2 ^m-1 .

The sector detection means 42 generates m digital signals bn-m + 1, bn-m + 2, ..., bn-1, bnｂ encoded to define 2m equal sector Pi 等 し い. This is means for detecting 2m sector Pi delimited by 2m-1 signals si.

The multiplexer means 43 is controlled by the m digital signals bn-m + 1, bn-m + 2,..., Bn-1, bn generated from the sector detecting means 42, and is generated from the signal generating means 41. 2m-1 of the above-mentioned signals si are processed, and the amplitude is constituted by a portion of the series of 2m-1 of the signals si between the average value C0 and the first threshold value L1. By a portion of one signal A between the first threshold L1 of the series of 2 ^m-1 signals si and the second threshold L2 higher than this threshold. This is an analog means for generating the other signal B to be constructed.

The fine interpolation means 44 is coded to subdivide each of the 2 ^m sectors Pi at an angle 2π / 2 ^m into 2 ^nm identical subsectors at an angle 2π / 2n to obtain the desired resolution. The (n−m) digital signals b1, b2,..., Bn-m−1, bn-m (here b1, b2,..., B8, b9) are multiplied by rotation pulses.

FIG. 21, FIG. 22 (A) to (E) and FIG. 23 (A) to (E) show an example in which the rotation sensor 2 is an absolute angle detection type. In this example, the magnetic encoder 2a is provided with two magnetic pole rows 2aA and 2aB, the number of magnetic pole pairs of one magnetic pole row 2aA is P, and the number of magnetic pole pairs of the other magnetic pole row 2aB is P + n. Therefore, there is a phase difference of n magnetic pole pairs per rotation between the magnetic pole arrays 2aA and 2aB, and the phases of the detection signals of the magnetic sensors 2ba and 2bb corresponding to these magnetic magnetic pole arrays 2aA and 2aB are It coincides with every 360 / n degrees of rotation.

The phase difference detection means 2cb constituting the signal processing means 2c outputs a phase difference signal as shown in FIG. 22 (E) based on the detection signals of the magnetic sensors 2ba and 2bb. The angle calculation means 2cc provided in the subsequent stage corrects the phase difference obtained by the phase difference detection means 2cb and then performs a process of converting into an absolute angle according to a preset calculation parameter.

22A and 22B show examples of magnetic pole patterns of both magnetic pole arrays 2aA and 2aB. FIGS. 22C and 22D show waveforms of detection signals of the magnetic sensors 2ba and 2bb corresponding to the magnetic pole arrays 2aA and 2aB. In the illustrated example, two magnetic pole pairs of the magnetic pole array 2aB correspond to three magnetic pole pairs of the magnetic pole array 2aA, and the absolute position within this section can be detected. FIG. 23E shows a waveform diagram of a phase difference output signal obtained by the phase difference detecting means 2cb of FIG. 21 based on the detection signals of FIGS. 22C and 22D.

Since the phase difference signals detected by the phase difference detecting means 2cb (FIGS. 22E and 23E) are affected by the magnetic interference and noise of the magnetic pole arrays 2aA and 2aB, they are actually distorted. A waveform with Therefore, the angle calculation means 2cc corrects the angle correction means 2cca to calculate an absolute angle with high detection accuracy.

11 to 16 show examples of wheel bearings provided with the rotation sensor 2. The wheel bearing 30 shown in FIGS. 11 and 12 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 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, for example, the radial type described above with reference to FIG.

The wheel bearing 30 shown in FIG. 13 and FIG. 14 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 FIGS. 18A and 18B. 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 FIGS. 18A and 18B. 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.

15 and 16 show an example in which the wheel bearing 30 is a third generation inner ring rotating type and is for supporting a driven wheel, and 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.

It should be noted that this automobile tire type recognition device can be applied widely from small cars such as passenger cars and taxis to large cars such as trucks, trailers and buses. The most preferable form is application to large vehicles such as trucks, trailers and buses. These automobiles require passengers and cargo to be transported safely and efficiently, so it is important to always keep the vehicle in a normal state. In addition to daily pre-service inspections, tire type information is detected during traveling, so that inspection errors and unavoidable circumstances prevent tires 1a suitable for road conditions from being worn. Even so, the driver can recognize the fact and take measures such as driving the vehicle according to the type of tire before the operation is affected, and the vehicle can be transported safely and efficiently.

DESCRIPTION OF SYMBOLS 1 ... Wheel 1a ... Tire 2 ... Rotation sensor 3 ... Signal processing unit 4 ... Tire type judgment unit

Claims (14)

1. A device for recognizing the type of automobile tire,
   A rotation sensor for detecting a rotation signal of a wheel so as to measure the speed of the automobile;
   Signal processing for extracting a rotational speed fluctuation synchronized with the rotation from the rotational signal detected by the rotational sensor, and obtaining a rotational speed fluctuation pattern including the rotational speed fluctuation synchronized with the rotation from the extracted rotational speed fluctuation Unit,
   For each of a plurality of tire types, pattern data of a rotational speed variation pattern, or a reference pattern storage unit in which characteristic parameters related to the tire type are registered,
   The acquired rotational speed variation pattern is compared with the pattern data registered in the reference pattern storage unit, or the characteristic parameter obtained from the acquired rotational speed variation pattern is registered in the reference pattern storage unit. A tire type recognition device including a tire type determination unit that estimates a tire type in comparison with a characteristic parameter.
2. 2. The automobile tire type recognition device according to claim 1, further comprising storing, as a reference pattern, an initial state or a normal rotation speed fluctuation pattern or a characteristic parameter obtained from the rotation speed pattern in the reference pattern storage unit. In addition, when the rotational speed fluctuation pattern acquired by the signal processing unit during traveling changes more greatly than a predetermined change reference from the reference pattern, this includes after puncture and tire replacement. When the inquiry information is output to the driver about the predetermined possibility and the driver permission information is input for the inquiry information, the rotation speed variation pattern acquired last is stored as the reference pattern as the reference pattern storage. An automobile tire type recognition device provided with a reference pattern re-registration means for re-registering with a section.
3. 3. The automobile tire type recognition device according to claim 1, wherein the signal processing unit synchronizes the rotation speed fluctuation pattern synchronized with the rotation with a rotation signal over a plurality of rotations of the rotation sensor. A type recognition device for an automobile tire that is obtained by performing the averaging process or the integration process.
4. 4. The automobile tire type recognition device according to claim 1, wherein the signal processing unit is configured to perform one or more setting processes for extracting fluctuations in rotational speed synchronized with the rotation. 5. An automobile tire type recognition device that is implemented in a travel speed range selected from the travel speed range.
5. 5. The vehicle tire type recognition apparatus according to claim 4, wherein the signal processing unit performs the extraction process for each of a plurality of travel speed ranges, and the tire type determination unit includes the signal processing unit that performs the extraction. An automobile tire type recognition device that performs estimation processing of a tire type for each speed range data to be processed, and comprehensively determines the tire type from the results of the plurality of estimation processes.
6. 6. The vehicle tire type recognition device according to claim 1, wherein the tire type determination unit includes an autocorrelation of a rotational speed variation pattern acquired by the signal processing unit and the reference. A tire type recognition device for a vehicle that discriminates the type of a tire from the amount of change with the autocorrelation of a reference rotation variation pattern stored in a pattern storage unit.
7. 7. The automobile tire type recognition device according to claim 1, wherein the rotation sensor is constituted by a rotation sensor having a zero phase or a rotation sensor having an absolute angle detection function, The signal processing unit obtains a difference between the rotational speed fluctuation pattern and the reference pattern in a state where the phases of the acquired speed fluctuation patterns are matched, and estimates a tire type based on the magnitude of the difference. Type recognition device.
8. 7. The automobile tire type recognition device according to claim 1, wherein the rotation sensor includes a magnetic sensor and a magnetic encoder or a pulser gear having a detected pole detected by the magnetic sensor. An automotive tire type recognition device configured to output a variation in magnetic strength due to rotation as an analog signal.
9. 7. The automobile tire type recognition device according to claim 1, wherein the rotation sensor includes a magnetic sensor and a magnetic encoder or pulser gear having a detected pole detected by the magnetic sensor, An automobile tire type recognition device comprising a multiplication circuit for outputting a rotation pulse for multiplying a detection signal of the magnetic sensor.
10. The vehicle tire type recognition device according to any one of claims 1 to 9, wherein, based on the tire type information estimated by the tire type determination unit, notification to a driver or control of the vehicle. An automobile tire type recognition device comprising tire type recognition result utilization means for changing a state.
11. 11. The vehicle tire type recognition device according to claim 10, wherein the tire type recognition result utilization means is a notification means provided in a driver's seat based on tire type information estimated by the tire type determination unit. A device for recognizing the type of an automobile tire to be notified.
12. 11. The vehicle tire type recognition apparatus according to claim 10, wherein the tire type recognition result utilization unit changes a control parameter of a vehicle control computer based on tire type information estimated by the tire type determination unit. An automobile tire type recognition device for performing safety control determined according to the type of tire.
13. 11. The vehicle tire type recognition device according to claim 10, wherein the tire type recognition result utilization means includes information on a tire type estimated by the tire type determination unit and weather during driving obtained from a weather information acquisition means. Based on the above, a tire tire type recognition device that issues a warning at a predetermined weather.
14. 11. The tire type recognition device for an automobile according to claim 10, wherein the tire type recognition result utilization unit is configured such that a computer mounted on the vehicle is a communication line based on tire type information estimated by the tire type determination unit. A tire tire type recognition device having a function of transmitting tire type information to a terminal of a predetermined sales office where vehicle inspection or tire replacement is possible.

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