JP3287712B2 - Wheel condition detection device based on tire uniformity components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for extracting a tire uniformity component (hereinafter, also simply referred to as a uniformity component) from a rotation signal of a vehicle tire and extracting the signal, and a wheel based on the uniformity component. Regarding the device for detecting the state, based on the tire uniformity component, in particular, for example, a standing wave detection device that detects a standing wave of the tire, a tire wear determination device that determines tire wear, and vehicle control using a wheel speed sensor. It is related to a device for performing.

[0002]

2. Description of the Related Art Conventionally, a tire type discriminating device for discriminating the type of a tire based on a tire uniformity component, a tire pressure detecting device for detecting a tire pressure condition, and a standing wave detecting device for detecting occurrence of a standing wave. No report has been made on a tire wear determining device for determining tire wear, and a sensor rotor abnormality detecting device for detecting partial missing of a wheel speed sensor rotor.

It is difficult to directly measure the tire pressure with the tire pressure warning device disclosed in Japanese Patent Application Laid-Open No. 5-133831. Therefore, the information when the tire pressure is normal and the information when the tire pressure drops are obtained from the wheel rotation speed. By comparing with the above, a decrease in air pressure is determined. Therefore, it is necessary to store the normal air pressure information in advance, or to perform initialization judgment at the time of normal air pressure (for example, at the time of refilling air) to obtain normal air pressure information. In this method, the tire pressure is indirectly detected.

[0004]

However, in the above-described tire air pressure warning device, the method of storing the normal air pressure information in advance cannot handle tire replacement or the like, because the information at the time of normal air pressure differs depending on the type of tire and the use condition. Therefore, the method of performing the initialization determination is effective.However, in order to perform the initialization without requiring the accessory components such as the initial switch processing, it is necessary to determine that the tire has been replaced by arithmetic processing and obtain normal air pressure information. There is. In addition, since it is difficult to directly detect a physical quantity of a detection target in a tire type determination device, a tire wear determination device, and the like, similarly, it is described only in a manner in which indirect measurement accuracy cannot be secured.

Accordingly, it is an object of the present invention to obtain and determine necessary state information by arithmetic processing based on a tire uniformity component. That is, (a) a tire pressure detecting device that detects a tire pressure state based on a tire uniformity component is obtained. (b) Based on the tire uniformity component, it is detected that the tire has been replaced by comparing the stored value with the detected value. (c) When a tire burst occurs, the tire is greatly distorted due to air leaks caused by stepping on a nail or the like, and at the same time, a standing wave is generated, and the burst occurs almost instantaneously. Therefore, if the occurrence of the standing wave can be detected, the burst can be avoided.
Therefore, a standing wave is detected based on the tire uniformity component. (d) The degree of tire wear affects tire grip. As the wear of the tire progresses, drainage on a wet road surface deteriorates, so that the grip force is reduced and running performance is deteriorated. In addition, when only a specific wheel is worn, since the grip force of the tire differs depending on the wheel, the traveling performance deteriorates during braking / driving and cornering. Therefore, it is detected that the tire has worn based on the tire uniformity component. (e) If the teeth of the wheel speed sensor rotor, which is the rotation signal generating means, are partially missing, the wheel speed pulse signal is affected, so that accurate wheel speed calculation cannot be performed. Therefore, partial missing teeth of the wheel speed sensor rotor are detected based on the arrangement data of the ratio of the partial rotation signal per one rotation of the wheel, which is a signal including the uniformity component.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a rotation signal output means for outputting a plurality of predetermined signals per one rotation of a vehicle wheel according to the rotation of the wheel. A partial rotation ratio extraction unit for extracting a ratio of a partial rotation signal per one rotation of the wheel from the signal; and removing an error amount based on a shape error inherent to the rotation signal output unit from the ratio sequence data. Component extracting means for extracting a tire uniformity component obtained as described above, and state signal output means for outputting wheel state information using the tire uniformity component. Further, in the configuration of the related invention, the wheel state information is tire replacement determination information, and the state signal output unit outputs the absolute value of a difference between the tire uniformity component of the vehicle stored in the storage unit and the latest tire uniformity component. If the sum of the values is larger than a predetermined value, a means for judging that the tire has been replaced and outputting a signal is provided.

Further, the present invention is also directed to the various tires, wherein the wheel state information is tire type determination information, and the state signal output means measures the tire uniformity component pattern in advance and stores it in a storage means. A means for outputting a tire type discrimination signal for identifying a tire type having a pattern with the best matching with the smallest matching difference in pattern matching with the uniformity component pattern of the wheel, The state information is tire pressure information, the state signal output means, from the tire uniformity component and the wheel speed value, characterized in that it is a means for outputting a tire pressure value according to a predetermined map, or The wheel state information is a standing wave occurrence determination signal, and the state signal is output. The means is for obtaining a difference between the maximum value and the minimum value of the tire uniformity component, determining that a standing wave is generated when the difference is equal to or more than a predetermined value, and outputting a standing wave generation signal. .

[0008] The present invention is further characterized in that the wheel state information is a tire wear determination signal, and the state signal output means is provided when the change from the initial tire uniformity component stored in the storage means exceeds a predetermined value. It is determined that the wear of the tire has occurred, characterized in that it is a means for outputting a wear state signal, or the wheel state information is a tire one wheel uneven wear determination signal, the state signal output means,
For each of the four wheels, regarding the total value of the deviation obtained by subtracting the standard value from the standardized tire uniformity component, when the difference between the tire of interest and the average value of the remaining tires is equal to or more than a predetermined value, the above-mentioned attention is paid. A means for outputting a signal by determining that the tire is unevenly worn, or
When the wheel state information is a tire uneven wear determination signal and the state signal output means determines that uneven wear has occurred in the tire when the sum of absolute values of the high frequency components of the tire uniformity component is equal to or greater than a predetermined value. And outputs a signal.

[0009] configuration of another invention, one revolution per wheel in accordance with the rotation of the wheels of the vehicle, and the wheel speed sensor rotor toothed for outputting a predetermined plurality of signals, from the signal, of the wheel A partial rotation ratio extracting means for extracting a ratio of a partial rotation signal per rotation, and data on one tooth of the wheel speed sensor rotor of the arrangement data of the ratio for obtaining a tire uniformity component; If the absolute value of the difference from the data of the tooth is equal to or larger than a predetermined value, the wheel speed sensor rotor determines that the tooth missing has occurred and outputs a signal.

[0010]

The uniformity component obtained from the rotation signal generating means including the signal rotor and the wheel speed sensor can be roughly divided into a relatively low-order uniformity component such as a tire uniformity and a relatively higher order component due to sensor processing. There is a uniformity component of In the present invention, the uniformity signal obtained from the wheel speed sensor is filtered, the higher-order component is determined by sensor processing, and the lower-order component is distinguished from the component due to the tire uniformity. ) To (5) (and from the sensor processing components
Extract the information shown in (6)).

(1) The tire is replaced by comparing the stored value of the tire uniformity component with the inspection value, for example, before the ignition is turned off (IG-OFF) and after the ignition is turned on (IG-ON). Is determined. (2) Integrated value of tire uniformity component and wheel speed V
The state of the tire pressure is detected from the relationship. (3) The occurrence of a standing wave is detected by detecting a large fluctuation amount of the tire uniformity component. (4) Tire wear is determined by comparing the tire uniformity of a new tire with the latest tire uniformity. By comparing the integrated value of the tire uniformity component of each wheel with the average value of the integrated values of the tire uniformity components of the other three wheels, it is detected that only one tire is unevenly worn. (5) By detecting the difference in uniformity between adjacent teeth, a partial missing tooth of the wheel speed sensor rotor is detected.

As a method of processing the sensor rotor constituting the rotation signal generating means, there is known a method of processing by rotating a cutting tool against a rotor. The cutting tool to be processed varies depending on the number of teeth of the sensor rotor, but is usually processed for every 1 to 5 teeth (an image of rotor processing is shown in the schematic diagram of FIG. 15). Therefore, the order of the uniformity component due to sensor processing is ((number of teeth in one round / working) Number of teeth), which can be distinguished from components of the tire uniformity generated at relatively low orders (1st to 9th orders).

[0013]

According to the present invention, by processing the tire uniformity component obtained from the rotation signals of the wheels of the vehicle , the condition of the tire can be characterized, various wheel conditions can be determined, and various controls can be performed. There are advantages that can be applied to According to the configuration of claim 1, since the wheel state is determined based on the tire uniformity component, there is an effect that a reliable detection device can be provided. Claim 2
In the configuration of (1), there is an advantage that the tire replacement can be automatically detected, and in the configuration of claim 3, various controls according to the tire type can be performed. Further, according to the configuration of claim 4, the tire pressure state can be detected, and various controls can be performed in accordance with the tire pressure. According to the configuration of claim 5, the occurrence of a dangerous standing wave is promptly notified, and the danger is anticipated. There is an advantage that can be prevented. Further, according to the configuration of claim 6, it is possible to automatically warn of deterioration of riding comfort such as shimmy and flutter, and tire wear leading to slip, tire burst, and the like.
It is possible to promptly warn of tire wear of any of the four wheels for safety. In the configuration of the eighth aspect, the danger can be prevented beforehand by notifying the instability due to the wear of the abnormal part. According to the configuration of the ninth aspect, the wheel rotation signal itself often used for control of the anti-skid control device or the like becomes abnormal, so that unstable control due to tooth missing can be prevented.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific embodiments and drawings. FIG. 1 shows the configuration of the wheel speed detection mechanism. Since the wheel speed detection mechanism 11 usually needs to detect the rotation state of each of the four wheels, it is almost always mounted on all the wheels, but the detection mechanism is the same. One is shown as a representative.

The wheel speed detecting mechanism 11 includes a signal rotor 12 (hereinafter, referred to as a rotor) that rotates with the wheels.
The rotor 12 is configured as a gear having a large number (for example, 96) of teeth made of a magnetic material at regular intervals. Then, the electromagnetic pickup 13 is brought close to the outer periphery of the rotor 12.
Is fixedly installed. This electromagnetic pickup 13
A change in the magnetic field caused by the passage of one tooth of the rotor 12 rotating with the wheel is detected, and for example, one sine wave detection signal is output each time one tooth passes.

That is, when the rotor 12 rotates with the wheels, the electromagnetic pickup 13 moves the rotor 12
With the passage of each tooth, a sine wave signal for counting the teeth is output. The sine wave pickup signal is input to the electronic control unit (ECU) 14.

The ECU 14 includes a waveform shaping circuit 141 to which a sine wave pickup signal is input, and a microcomputer 142 to which a pulse signal output from the waveform shaping circuit 141 is input. The rise of the rectangular wave signal from the waveform shaping circuit 141 obtained by shaping the wavy pickup signal is used as an interrupt signal.

From the rotation signal obtained from the rotor 12 serving as the rotation signal generating means, an amount indicating the uniformity of the tire is obtained. Such quantities have not been particularly defined so far, and have only been analyzed for tire noise due to, for example, variations in the force on the tires that affect uniformity. Therefore, it is sufficient that this amount is such as to generate a signal when the uniformity of the tire collapses. In the present invention, the value is set to 0 in an ideal tire uniform state as follows. The quantity is defined as the tire uniformity component.

FIG. 2 shows an example in which the uniformity component is detected to obtain the data, and the data is used to determine the tire replacement. FIG. 2 shows a flowchart of a tire replacement determination including a process for extracting a uniformity component by the microcomputer 142 from the detected rotation signal.

Hereinafter, the flowchart of FIG. 2 will be described. (1) First, in step 50, the waveform shaping circuit 141 of FIG.
, The time interval (Δtn) of each pulse signal input to the microcomputer 142 is detected. Where n is
Of the rotor 12 (rotor tooth No.), 1 to N
(N is the number of rotor teeth). FIG. 3 (a) shows this state, in which the horizontal axis indicates the rotor tooth number and the vertical axis indicates Δtn. Note that the horizontal line indicating the data of each tooth represents only one data point. (2) In step 60, the average value of the pulse intervals Δt _{1 to} Δt _N for one rotation of the rotor 12 ((ΣΔt _n ) / N = Δt)
_M ) is calculated. (3) In step 100, Δθ is obtained from Expression 1 and Expression 2.
(n) is detected. Here, Δθ (n) is obtained by adding processing error information Δθ of the rotor 12 to the tire uniformity component Δθ _u (n).
_The value to which _r (n) is added, and means a value obtained from a wheel speed sensor signal for each tooth of the rotor 12. In Equation 1,
(Wheel rotation time for each rotor tooth / wheel one rotation time)
Is detected for each rotation of the wheel. The obtained Δθ ′ (n) is obtained for M wheel rotation speeds (FIG. 3 (b)), and Δθ ′ (n) for M times obtained by Expression 1 in Expression 2 is averaged to obtain ΔΔ ′ (n).
θ (n) is calculated (FIG. 3 (c)). Therefore, steps 50 to 110 are repeated M times as step processing. (A ratio averaging means for calculating an average value of the ratio per the M rotations of the wheel (M: a positive number).)... Either included in the partial rotation ratio extraction means or measured for M rotations at a time Would.

[Equation 1]

[Equation 2]

Here, the processing error information Δθ of the rotor 12
_r (n), for each vehicle a known value, the rotation angle theta _n of the rotor each tooth, the average value of the rotation angle of total teeth N (2π / N)
It is expressed by the rotation angle ratio divided by (see Expression 3). This value is stored in the microcomputer 142 as measurement data.

[Equation 3] Δθ _r (n) = θ _n / (2π / N) (θ _n : rotation angle of each tooth of the rotor)

In step 110, Δθ _u (n) for all teeth of each rotor tooth, which is a tire uniformity component
Is detected by the following two means. These two means are complementary, and may be obtained by either of them, or both may be obtained and averaged.

(A) The value of Δθ _r (n) of an m-tooth machining rotor in which m-tooth (2 ≦ m ≦ 5) are simultaneously machined is a value having a high-frequency component of the m-tooth period. Therefore, in the first means,
A high-frequency component of rotor machining accuracy information of m-tooth machining is removed from Δθ (n) by a Butterworth second-order low-pass filter shown in Expression 4, and a tire uniformity component Δθ
_u (n) is obtained (see FIG. 3 (d)). In this case,
Applicable when formula is not required or not required. In the configuration shown in FIG. 1, the low-pass filter is obtained by the operation of the microcomputer 142. However, the low-pass filter can be obtained by processing the filter by using hardware.

[Equation 4] Δθ _u (n) = L1 * Δθ (n) + L2 * Δθ (n−
1) + L3 * Δθ (n-2) + L4 * Δθ _u (n-1) + L5 * Δθ _u (n
-2) [However, Δθ (0) = Δθ (N), Δθ (-1) = Δθ (N-1)
, Δθ _u (0) = Δθ _u (-1) = 0, L1, L2, L3, L4, L5
Is a constant, * is a multiplication symbol]

(B) Since Δθ (n) is a value obtained by combining the tire uniformity and the rotor processing accuracy information, the second means obtains Δθ _u (n) from equation (5).

## EQU5 ## (Δθ _u (n) −1) = (Δθ (n) −1) −
(Δθ _r (n) −1) That is, the microcomputer 142 performs arithmetic processing using the previously obtained data of Δθ _r (n) to obtain a uniformity component Δθ _u (n). In addition, the fact that 1 is subtracted from all terms in Equation 5 is for the sake of simplicity in data processing, and each term is indicated only by a deviation from a standard value (= 1). It is.

The uniformity component Δ thus obtained
θ _u (n) is a normalized data sequence Δ as shown in FIG.
θ _u (n), which has characteristics in accordance with the condition of the tire, and various determinations can be made by grasping the characteristics of the uniformity component. The uniformity component detection device is similar in appearance to the wheel speed detection device, but differs in data processing, and is characterized by having a means for extracting the uniformity component. By obtaining the uniformity component, a great advantage that various wheel states can be detected is produced. Hereinafter, a wheel state detection device that detects various characteristics using a uniformity component will be described.

(Tire Replacement Determination) After extracting the uniformity components, a tire replacement determination is made in step 120. Tire uniformity naturally depends on the type of tire and usage. Therefore, the tire uniformity information Δθ _u (n) ₁ of each tire before IG-OFF is stored in the microcomputer 142, and Δθ _u obtained after IG-ON is stored.
(n) If Equation 6 is satisfied as compared with ₂ , it is determined that the tire has been replaced, and a determination signal is output. Where Equation 6
The equation performs pattern matching (correlation) between Δθ _u (n) ₁ and Δθ _u (n) ₂ and calculates the Δ
θ _u (n) ₁ and Δθ _u (n) _{2 determine} that the rotor tooth numbers match, and the integrated value of the difference between Δθ _u (n) ₁ and Δθ _u (n) ₂ for that pattern Is compared with the tire replacement determination value a to determine the tire replacement.

[Equation 6] [I: Takes a value from 0 to N-1 (n + i)% N: Remainder of dividing n + i by N MIN (): Represents the minimum value in () when the value of i is changed Δθ _u (n) ₁ : Tire uniformity information before IG-OFF Δθ _u (n) ₂ : Tire uniformity information after IG-ON a: Tire replacement judgment value]

(Second Embodiment) The flowchart shown in FIG. 4 is for obtaining the tire air pressure. The flowchart shown here also includes a process of extracting a tire uniformity component, as in the first embodiment. Therefore step 5
Steps 0 to 110 are the same as in the first embodiment.

At step 130 after the extraction of the uniformity component, the state of the tire pressure is detected from the uniformity component Δθ _u (n). The tire uniformity also changes depending on the tire pressure P, and has characteristics as shown in FIG. 5 in the range of use (see Equation 7). In this region, the value of S decreases as the air pressures P ₁ , P ₂ , P ₃ (P ₁ <P ₂ <P ₃ ).

[Equation 7] [S: Dispersion index] The meaning of this S is -1 and 0 because Δθ _u (n) is 1 when uniform. Therefore, a value appearing at 出 る means that the non-uniformity is large, and therefore means dispersion.
This S depends on speed and pressure as shown in FIG.
From the wheel speeds V and S, the state of the tire air pressure can be detected from equation (8) (map).

P = P _map (S, V) [P: tire pressure P _map : air pressure judgment map]

(Third Embodiment) When a standing wave is generated while the vehicle is running, the shape of the tire, that is, the tire uniformity greatly changes, so that the tire uniformity component Δθ _u (n) is compared with a normal value. It shows a big change. As shown in FIG. 6, the tire uniformity component has a large temporal variation as soon as a standing wave occurs. FIG. 6 shows the Δ of one tooth.
This shows how the value of θ _u (n) changes with time t. Of course, a similar course is shown for Δθ _u (n) for different teeth. This large temporal variation does not always occur in the uniformity component of each of the teeth 1 to N at the same time. Therefore, a large variation also occurs in the arrangement of the teeth, that is, in the uniformity component of one rotation. Taking advantage of this point, the standing wave is detected by the following two methods.

(I) First, as a first method, a variation within the uniformity component Δθ _u (n) is determined and used as a standing wave determination criterion. In the flowchart shown in FIG.
In step 140 after the extraction of the uniformity component, a change in the uniformity component is represented by a difference between a maximum value and a minimum value represented by Expression 9, and this difference is determined by a predetermined determination value b _1.
In this case, it is determined that a standing wave has occurred.

[Equation 9] Δθ _u (n) _max − Δθ _u (n) _min ≧ b ₁

Alternatively, using a storage means, the temporal change of the uniformity component of one tooth over time is determined by a predetermined value b.
_In the case of _two or more, a standing wave may be generated.

| Δθ _u (n) _t − Δθ _u (n) _t-1 | ≧
b ₂ [t-1: previous measurement (memory value) t: current measurement]

(II) As can be seen from the large change in FIG. 6, the S value represented by the equation (7) naturally increases. Therefore, this S
Seeking value, it determines that the standing wave occurs when a larger than a predetermined judgment value b _3.

Therefore, at step 140, a standing wave occurrence determination process is performed using one or both of these two methods.

(Fourth Embodiment) Next, an example in which a tire wear state is determined after extracting a tire uniformity component will be described. As shown in the flowchart of FIG. 8, in step 150 after the extraction of the uniformity component, the processing of tire wear detection is performed.

If the block shape of the tread of the tire is abnormally worn, the portion will fluctuate when the tire rotates, and the uniformity component will be different from that of a new tire. Therefore, the difference is detected and it is determined that partial wear has occurred. However, since this difference is a minute change and is difficult to detect, the following method is used.

The tire uniformity component Δθ _u (n) ₃ when the tire is new is stored by the initial switch function or the like, and is always compared with the latest detected value uniformity component Δθ _u (n) ₄ to obtain the equation (11). When the expression is satisfied, it is determined that the tire has unevenly worn. Here, equation 11 is ΔΔ
Pattern matching between θ _u (n) ₃ and Δθ _u (n) ₄ is performed, and Δθ _u (n) ₃ and Δθ
_u (n) _{4 determines} that the rotor tooth numbers match, and the product sum of the differences between Δθ _u (n) ₃ and Δθ _u (n) ₄ in that pattern is greater than a predetermined determination value c. If it is larger, it is determined that the wear is uneven.

[Equation 11] [I: Takes a value from 0 to N-1 (n + i)% N: Remainder of dividing n + i by N MIN (): Represents the minimum value in () when the value of i is changed Δθ _u (n) ₃ : new tire uniformity information Δθ _u (n) ₄ : latest detected tire uniformity information c: tire wear determination value]

(Fifth Embodiment) In the fourth embodiment described above, it was detected that the tread block of the tire was worn abnormally for only one wheel. Normally, there are four tires, so uneven wear can be detected by comparing with other tires. Therefore, as shown in the flowchart of FIG. 9, it is detected that one of the four wheels has been unevenly worn.

After the step of extracting the uniformity component is performed in the first half, similarly to the above-described flowchart, in step 160, it is determined that one wheel is unevenly worn. Here, as a configuration, usually all four wheels are provided with a rotor 12 as a rotation speed detecting means, and each wheel has the system shown in FIG. A system for performing signal processing may be used.

The S values of Equation 7 obtained from the uniformity components of each tire are represented by S1, S2, S3,
S4. Here, the S value of a particular notable wheel is represented by S
The other three wheels are designated as S2, S3, and S4.
At this time, if the tire of interest is unevenly worn,
This S1 naturally takes a large value and the others are small.
The condition shown in Equation 2 holds, and it is determined that one of the wheels is partially worn. Of course, focusing on other tires, Equation 12
The formula is determined and a determination is made for each wheel.

[Equation 12] S1 − {(S2 + S3 + S4) / 3} ≧ d [d: one-wheel uneven wear determination value]

(Sixth Embodiment) In the fourth embodiment, the wear over the entire circumference of the tire is detected. This time, the detection is performed when a part of the circumference of the tire is abnormally worn. The tire is in a locked state at the time of sudden braking, and a portion in contact with the road surface is worn, so that only a part of the circumference is worn and a flat spot is formed. Therefore, when the vehicle runs on the tire, abnormal vibration may occur. Alternatively, when parking, the ground contact portion of the tire may be dented by receiving pressure, and a flat spot may be temporarily formed. The latter flat spot does not become abnormal, and the tires are homogenized and the flat spot disappears as the vehicle starts running. Therefore, what is abnormal is the former flat spot,
The detection is performed as follows. That is, since the flat spot due to parking disappears after a certain period of time after the vehicle starts running, it is desirable to perform this detection after a certain period of time after the vehicle starts running.

In the flowchart shown in FIG. 10, the first step is to extract the uniformity component. Then, in step 170, Δθ ′ _u shown in Expression 13
Find (n). This is a high frequency component of the uniformity component Δθ _u (n) of the worn portion, and is obtained by using a Butterworth second-order high-pass filter.

[Expression 13] Δθ ′ _u (n) = H1 * Δθ _u (n) + H2 * Δθ _u
(n-1) + H3 * Δθ _u (n-2) + H4 * Δθ ' _u (n-1) + H5 *
Δθ ' _u (n-2) [However, Δθ _u (0) = Δθ _u (N), Δθ _u (-1) = Δθ
_u (N-1), Δθ ' _u (0) = Δθ' _u (-1) = 0, H1, H2,
H3, H4, H5 are constants * is a multiplication symbol

The high-frequency component Δθ ′ _u (n) means a variation of the uniformity component caused by the flat spot, and does not mean a high-frequency component excluded by Equation 4 when obtaining the uniformity component. . That is,
The high-frequency component indicates a component amount deviating from a normal uniformity component (although there is a possibility that a part of the component may be excluded by Expression 4). Therefore, if there is no fluctuation due to a partial flat spot, this high-frequency component Δ
θ ′ _u (n) is 0 in most regions. When the fluctuation due to the flat spot occurs, only the tooth corresponding to that part has a value. This is shown in FIG.
FIG. 11 (a) shows a state in which a component due to a flat spot is generated in the uniformity component, and FIG. 11 (b) shows a state in which only the high-frequency component is extracted by Expression 13. In this figure, for simplicity, the data strings 1 to N are shown as an analog continuous graph.

Once a flat spot occurs,
Since the worn tire does not recover, the uniformity high-frequency component in that portion continues to have a value. Then, while observing the progress of this amount by integration according to Equation 14, if it exceeds a predetermined determination value e, it is determined that partial wear has occurred to the extent that abnormalities occur. Of course, the determination of the progress is not limited to equation (14).

[Equation 14] [E: Partial wear judgment value]

(Seventh Embodiment) Next, in the rotor 12 which is a rotation signal generating means, if the rotor itself is chipped, the signal fluctuates to change Δθ (n) (Equation 2). As shown in FIG. 13, the missing tooth of the rotor 12 means that a part of the tooth is lost for some reason. This change also becomes abnormal as a rotation signal, and it is necessary to generate some signal. Therefore, the missing tooth detection of the rotor is performed by using the equation (2).

When the rotor 12 has a missing tooth, the electromagnetic pickup 13 of the sensor for detecting the rotation signal generates a signal different from that of the other teeth, and as a result, as shown in FIG. Before the extraction, a sharp impulse-like or spike-like component is generated in the sequence data of the ratio including the machining error of the tooth. Since the components are characteristic as described above, FIG.
As shown in the flowchart of FIG. 7, in step 180 when extracting the uniformity component, the spike-like feature is detected and it is determined that tooth missing has occurred. Here, since the value of Expression 2 between the tooth having a missing tooth and the adjacent tooth is greatly different, the comparison shown in Expression 15 is performed, and when the value becomes equal to or more than the predetermined tooth missing determination value f. Is determined to be missing.

| Δθ (n) −Δθ (n-1) | ≧ f [f: rotor tooth missing determination value]

By detecting the missing tooth of the rotor 12 in this way, it is possible to prevent malfunction due to missing tooth in a system that controls by a wheel speed sensor signal such as an anti-skid control device or a tire pressure alarm device. it can.

In each of the embodiments described above, various wheel states are determined using the same uniformity component. Since the manner of the tire uniformity components for various tire states is unique to each other, and the data processing or function used for each is also independent, each is detected independently. Therefore, it is possible to prevent one of the determinations from being mingled with another determination. Of course, a plurality of determination results are output for states that are simultaneously established. Therefore, when all the determinations are performed at the same time, one of the respective determinations is prioritized, and it is possible to avoid a situation in which the determination is always hidden and not determined.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a wheel speed detection mechanism to which the present invention is applied.

FIG. 2 is a flowchart showing signal processing for performing tire replacement determination.

FIG. 3 is an explanatory diagram of a process of extracting a uniformity component by processing a signal from a rotation signal generating unit.

FIG. 4 is a flowchart showing signal processing for detecting a tire pressure state.

FIG. 5 is a characteristic diagram showing a wheel speed and a pressure dependency of an S value represented by Expression 7;

FIG. 6 is a characteristic diagram of a uniformity component when a standing wave occurs.

FIG. 7 is a flowchart showing signal processing for detecting occurrence of a standing wave.

FIG. 8 is a flowchart showing signal processing for detecting uneven tire wear.

FIG. 9 is a flowchart showing signal processing for detecting tire wheel wear.

FIG. 10 is a flowchart showing signal processing for detecting partial wear of a tire.

FIG. 11 is a characteristic diagram showing a uniformity component generated by partial wear of a tire and a signal component of an abnormal part extracted by Expression 13.

FIG. 12 is a flowchart showing signal processing for detecting rotor tooth missing.

FIG. 13 is a schematic explanatory view of a rotor tooth chipping.

FIG. 14 is a characteristic diagram of alignment data including a uniformity component when a rotor tooth is missing.

FIG. 15 is a schematic explanatory view of processing a rotor tooth.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Wheel speed detection mechanism 12 Signal rotor 12'Signal rotor being processed 13 Electronic pickup 14 Electronic control unit (ECU) 141 Waveform shaping circuit 142 Microcomputer 20 Bit for tooth processing

──────────────────────────────────────────────────続 き Continuing on the front page (72) Nobuyoshi Onoki, 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (72) Hideki Ohashi 1, Toyota-cho, Toyota-shi, Aichi, Toyota Toyota Motor Corporation (72) Inventor Hiroyuki Kawai 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hiroyoshi Kojima 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Koji Umeno 41 Toyota Chuo R & D Co., Ltd. in Toyota Central Research Laboratory Co., Ltd. (72) Inventor Katsuhiro Asano, 41-Cho Chu-Cho Yokomichi, Nagakute-cho Aichi-gun Aichi-gun Toyota Central Research Laboratory Co., Ltd. (56) References JP-A-5-138331 (JP, A) JP-A-63-287608 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B60C 23/00-23/08

Claims (9)

(57) [Claims] 1. A rotation signal output means for outputting a plurality of predetermined signals per rotation of a wheel according to rotation of a wheel of a vehicle, and a ratio of a partial rotation signal per rotation of the wheel based on the signal. A partial rotation ratio extraction unit that extracts a tire uniformity component obtained by removing an error amount based on a shape error unique to the rotation signal output unit from the sequence data of the ratio; A wheel state detecting device based on a tire uniformity component, comprising: a state signal output unit that outputs wheel state information using a tire uniformity component. 2. The vehicle according to claim 1, wherein said wheel state information is tire replacement determination information, and said state signal output means outputs an absolute value of a difference between a vehicle tire uniformity component stored in a storage means and a latest tire uniformity component. 2. The wheel state detecting device according to claim 1, wherein the unit is configured to determine that the tire has been replaced and output a signal when the sum is greater than a predetermined value. 3. The tire condition information is tire type determination information, and the state signal output means measures the tire uniformity component pattern in advance and measures the uniformity components of various tires stored in a storage means. 2. The tire uniformity according to claim 1, wherein the means for outputting a tire type discrimination signal for identifying a tire type having a pattern that matches the pattern with the smallest matching difference in the pattern matching with the pattern. Wheel state detection device by component. 4. The apparatus according to claim 1, wherein the wheel state information is tire pressure information, and the state signal output means is means for outputting a tire pressure value according to a predetermined map from the tire uniformity component and the wheel speed value. The wheel state detecting device according to claim 1, wherein the tire uniformity component is used. 5. The wheel state information is a standing wave occurrence determination signal, wherein the state signal output means obtains a difference between a maximum value and a minimum value of the tire uniformity component, and when the difference is equal to or more than a predetermined value, 2. A wheel state detecting device based on a tire uniformity component according to claim 1, further comprising means for judging occurrence of a standing wave and outputting a standing wave occurrence signal. 6. The tire condition information output means is a tire wear determination signal, and the state signal output means outputs a signal to the tire when the change from the initial tire uniformity component stored in the storage means exceeds a predetermined value. 2. A means for determining that wear has occurred and outputting a wear state signal.
A wheel state detecting device using the tire uniformity component described in the above. 7. The wheel condition information is a tire one wheel uneven wear determination signal, and the condition signal output means sums deviations obtained by subtracting a standard value from a standardized tire uniformity component of each of the four wheels. 2. The method according to claim 1, wherein when the difference between the tire of interest and the average value of the remaining tires is equal to or greater than a predetermined value, the tire is determined to have unevenly worn and outputs a signal. A wheel condition detection device based on the tire uniformity component. 8. The tire according to claim 1, wherein the wheel state information is a tire uneven wear determination signal, and the state signal output means determines that the tire has uneven wear when the sum of absolute values of high frequency components of the tire uniformity component is equal to or greater than a predetermined value. 2. A wheel state detecting device based on a tire uniformity component according to claim 1, further comprising means for judging that the occurrence has occurred and outputting a signal. 9. A wheel-shaped wheel speed sensor rotor for outputting a plurality of predetermined signals per rotation of a wheel according to rotation of a wheel of a vehicle, and a partial rotation per rotation of the wheel based on the signal. A partial rotation ratio extracting means for extracting a ratio of signals; and a sequence data of the ratio for obtaining a tire uniformity component, data on one tooth of the wheel speed sensor rotor, and data on teeth before and after the tooth. And a state signal output means for outputting a signal when the absolute value of the difference is equal to or more than a predetermined value and determining that the tooth loss of the wheel speed sensor rotor has occurred. Detection device.