JP4769179B2 - Judging method and judging device of different diameter wheel - Google Patents

Description

  The present invention relates to a different diameter wheel determination method and a determination apparatus for determining a different diameter wheel among wheels mounted on a vehicle.

In a four-wheel vehicle, a different diameter wheel (for example, a temper tire, a small diameter tire) having a diameter different from other wheels may be attached to any of the four wheels. In addition, even when such special tires are not installed, due to the large decrease in air pressure of specific tires, they may behave in the same way as when different diameter wheels are installed. .
In anti-lock brake control (hereinafter referred to as ABS control) of a four-wheel vehicle, in order to execute appropriate ABS control, it is determined whether or not such different-diameter wheels are mounted, and the determination The result needs to be reflected in the ABS control. Moreover, it is not limited to the case of braking control like ABS control, It may be necessary to reflect the information regarding the presence or absence of mounting | wearing of a different diameter wheel with respect to the drive control which drive | works a four-wheel vehicle.

As a conventional method for determining different diameter wheels, “the front wheel left-right speed difference ΔV1 and the rear wheel left-right speed difference ΔV2 are calculated, and if either of the two exceeds the reference value, either the left or right axle difference on the speed difference side that has exceeded A technique is disclosed in which it is determined that different diameter wheels are mounted and the ABS control is interrupted (see, for example, Patent Document 1).
As another method for determining different diameter wheels, “if any one of the four wheels has a high wheel speed (assuming that the different diameter wheels have a small diameter), the wheel is determined to be a different diameter wheel.” A technique is disclosed (for example, see Patent Document 2).
Other methods for determining different diameter wheels include: “the speed ratio of the slower front wheel speed to the front wheel left / right speed difference ΔV1, the speed ratio of the rear wheel speed to the rear wheel left / right speed difference ΔV2, the front / rear wheel speed difference Δ Calculate the speed ratio of the slow front wheel or rear wheel average speed relative to V3 (= difference between the average front wheel speed and the average rear wheel speed. If each speed ratio exceeds the reference value, the corresponding wheel is determined as a different diameter wheel. " A technique is disclosed (for example, see Patent Document 3).
Other different diameter wheel judgment methods include: “Calculate front wheel left / right speed average, rear wheel left / right speed average, left front / rear speed average, right front / rear speed average, left / right speed ratio, front / rear speed ratio, and set each value within the reference range. A technique is disclosed in which it is determined whether or not the wheel is within a range, and one or two wheels with different diameter wheels are determined from a combination of values that are within a reference range (see, for example, Patent Document 4).
JP 59-6163 A JP 2001-39291 A JP 2004-90703 A JP 2004-131010 A

However, the conventional method for determining different diameter wheels has the following problems.
In the above-mentioned Patent Documents 1 and 3, the technology is limited to knowing whether or not different-diameter wheels are mounted, and it is specified in which position of the four wheels the different-diameter wheels are mounted. What can not be done is a problem. Moreover, in the technique of patent documents 1-3, when two or more different diameter wheels are mounted | worn, it is a subject that an incorrect determination may be made.
In the technique of Patent Document 4 described above, the parameter of the set time incorporated in the determination flow plays an extremely important role in preventing erroneous determination. However, this set time is experimentally determined in advance and is considered to be an unstable element whose optimum value greatly varies depending on the vehicle type and the driving environment, and there is a problem that the accuracy of determination of different diameter wheels is lacking in stability.

  The present invention has been developed to solve the above-described problems, and is not limited to the number of different-diameter wheels mounted on the vehicle, and accurately determines the position where the different-diameter wheels are mounted. It is an object of the present invention to provide a method of determining different diameter wheels and a determination device thereof.

In order to solve the above-described problems, the present invention is a method for determining different diameter wheels among four wheels of a vehicle on which four wheels are mounted, each of the four wheels. Detecting a wheel speed for the wheel, calculating a speed ratio of the wheel speeds of the other wheels based on a wheel speed of a reference wheel alternatively selected from the four wheels. Determining whether the speed ratio is out of a specified range based on 1, and if the number of corresponding wheels out of the specified range is 0, it is determined that there are no different diameter wheels. When the number of corresponding wheels out of the specified range is 1, the wheel is specified as the only wheel of different diameter, and when the number of corresponding wheels out of the specified range is 3, Specify the reference wheel as the only wheel of different diameter, and the specified range Conditional speed of the wheel deviates is two, viewed including the steps of two wheels that is not two wheels or corresponding are applicable are specified as being different-diameter wheels, out of the above specified range the When the number of corresponding wheels is two, when the two different diameter wheels are not arranged on the same side of the vehicle, a warning is normally given, and the two different diameter wheels are the same in the vehicle. When it is arranged on the side, a heavy warning is given .
More preferably, the determination as to whether or not the specified range is outside is made by determining that the value obtained by subtracting 1 from the speed ratio exceeds the initially set upper limit threshold and that the specified range is outside the specified range. If the value obtained by subtracting the speed ratio exceeds the initially set lower limit threshold value, it is determined that the value falls outside the specified range.
More preferably, when the number of hits of the wheel determined to exceed the upper limit threshold and deviate from the specified range is two, the two corresponding wheels are identified as different diameter wheels, When the number of hits of the wheels determined to exceed the lower limit threshold and deviate from the specified range is two, it is specified that the two non-corresponding wheels are different diameter wheels. .

By constructing the invention in this way, any one of the four wheels is set as a reference wheel, and a speed ratio between the wheel speed of the reference wheel and the wheel speeds of the other wheels is obtained. Then, whether or not any of the wheels is a different diameter wheel can be determined based on whether or not the speed ratio is included in a predetermined numerical range.
By configuring the invention as described above, when one different-diameter wheel is mounted on the vehicle, the vehicle can specify the position where the different-diameter wheel is mounted.
Even if two different-diameter wheels are mounted on the vehicle, the position where the different-diameter wheels are mounted can be determined by assuming that the different-diameter wheels are generally small-diameter. Can be identified. Further, it can be recognized whether the combination of the positions of the two different-diameter wheels mounted is coaxial, diagonal or on the same side of the four wheels.

The invention further includes a step of determining that the vehicle is traveling straight, and is configured not to determine that the vehicle corresponds to the different diameter wheel when it is determined that the vehicle is not traveling straight. Also good.
By configuring the invention in this way, there is no possibility of erroneous determination of different diameter wheels when the vehicle is turning.

  Further, the invention may be configured such that the step of determining that the vehicle is traveling straight is performed based on the calculated speed ratio.

Further, the invention may be configured such that when the vehicle stops, the determination of the different diameter wheel is executed every time the vehicle starts after stopping.
Further, the invention may be configured such that the determination of the different-diameter wheel is re-executed after the set time has elapsed even if the determination that the different-diameter wheel is absent is made once while the vehicle is running. .
By configuring the invention in this way, the accuracy of determination of different diameter wheels is improved.

  According to the present invention, without being limited to the number of different-diameter wheels mounted on a vehicle, a method for determining a different-diameter wheel that can accurately determine the position where the different-diameter wheel is mounted and its An apparatus is provided.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
First, prior to the description, a vehicle to which the different diameter wheel determination device according to the present invention is applied will be described. As shown in the lower side of FIG. 1, the vehicle c applied to the present invention has four wheels T _i (T _FR , T _FL , T _RR , T _RL ) at four positions on the front, rear, left and right with respect to the traveling direction. Is provided. Among these wheels T _i , the front right side in the traveling direction is the wheel T _FR , the front left side is the wheel T _FL , the rear right side is the wheel T _RR , and the rear left side is the wheel T _RL . Further, in the vicinity of these four wheels T _i (T _FR , T _FL , T _RR , T _RL ), sensors _Si (S _FR , S _FL , S _RR ) for detecting the wheel speed of these wheels T _i are provided. S _RL ).

As shown in the upper side of FIG. 1, the different diameter wheel determination device 10 according to the present embodiment includes a wheel speed detection unit 20, a speed ratio calculation unit 30, a reference wheel selection unit 35, a storage unit 36, and a different diameter. The determination unit 40 includes a straightness determination unit 50 and a determination display unit 60. The different diameter wheel determination device 10 configured as described above determines the number and positions of the different diameter wheels T _i (T _FR , T _FL , T _RR , T _RL ) among the four wheels of the vehicle c. It is.

The wheel speed detector 20 includes an FL speed detector 21, an RL speed detector 22, an RR speed detector 23, and an FR speed detector 24, which are respectively sensors S _i (S _FR , and outputs _{S FL,} S _RR, the wheel speed ω _i (ω _FR wheel _{T i} in question is connected to the _{S RL), ω FL, ω} RR, the omega _RL).

The speed ratio calculator 30 includes an FL speed ratio calculator 31, an RL speed ratio calculator 32, an RR speed ratio calculator 33, and an FR speed ratio calculator 34. The speed ratio calculation unit 30 then selects the wheel of the reference wheel T ₀ that is alternatively selected from the four wheels T _i (T _FR , T _FL , T _RR , T _RL ) by the reference wheel selection means 35. based on the velocity omega _0, as shown in the following equation (1) is for calculating the speed ratio K _i between the wheel velocity omega _i in the other wheel T _i. Then, the calculated value of the speed ratio K _i is temporarily stored in the storage unit 36. Note that “selectively selected” means that the reference wheel T ₀ may be determined in advance, may be determined randomly, or may be changed in order.

K _i = ω _i / ω ₀ (i = FR, FL, RR, RL) (1)
(Ω ₀ is alternatively selected from ω _FR , ω _FL , ω _RR , and ω _RL )

Illustrates the calculation result of the speed ratio K _i in the velocity ratio calculation unit 30 in FIG. 2. Here, the reference wheel T ₀ shows a case where the rear right wheel T _RR is set. Furthermore, the case where the different diameter wheel with which it is mounted | worn has a diameter about 20% smaller than a normal wheel is shown.
Then, FIG. 2 (a), and if the different-diameter wheel is not mounted (first stage), in order T _FR only from case (second stage of different-diameter wheels on only one wheel of the four wheels is mounted , T _FL only, T _RR only, and T _RL only with different diameter wheels).
The FIG. 2 (b), if the different-diameter wheels is mounted on the two-wheel of four-wheel (in order from the upper _{T FR} and _{T FL, T RR} and _{T RL, T RR} and _{T FL, T FR} and T _{RL, T FR} and _{T RR,} if fitted only _{T FL} and _{T RL)} is shown.

In the calculation result of FIG. 2, when the same diameter wheel is attached to the reference wheel T ₀ (the right rear wheel T _RR ), the speed ratio K _i of the other same diameter wheel is “1”, The speed ratio K _i is “1.25” (in the case of a-2, 3, 5, b-1, 4, 6).
When a different diameter wheel is attached to the reference wheel T ₀ (the right rear wheel T _RR ), the speed ratio K _i of the different diameter wheel is “1”, and the speed ratio K _i of the same diameter wheel is “0”. .8 "(in the case of a-4, b-2, 3, 5).

Returning to FIG. 1, the description will be continued.
The different diameter determination unit 40 includes a threshold setting device 41, a different diameter determination device 42, and a different diameter wheel determination device 43. Then, the different diameter determination unit 40 determines whether the calculated speed ratio K _i (i = FL, RL, RR, FR) is out of a specified range based on 1, whether the four wheels (T _i ; i = Fl, RL, RR, FR), a wheel corresponding to a different diameter wheel is determined.

Threshold setter 41, the threshold value m (upper limit threshold value m ₁ to determine whether the wheel on the basis of the speed ratio K _i with different diameter determiner 42 to be described later corresponds to any of the different-diameter wheel or the same diameter _wheel, the lower threshold m ₂ ) is set. In this embodiment, the threshold value set by the threshold value setter 41 is set so that m (m ₁ , m ₂ ) takes a positive value (0 <m), but there is no particular limitation, and the speed ratio Any value can be used as long as the upper and lower limits of the numerical value range of K _i can be defined. Further, the upper limit threshold m ₁ and the lower limit threshold m ₂ may be different from each other or the same number.

The different diameter determiner 42 substitutes the speed ratio K _i output from the speed ratio calculation unit 30 into an inequality as shown in equations (2) and (3), and based on whether this inequality is satisfied, the speed ratio It is determined whether or not K _i is out of a specified range based on 1.
That is, if the value obtained by subtracting 1 from the speed ratio K _i exceeds the initially set upper limit threshold value m ₁ (when the expression (2) is satisfied), it is determined that the value falls outside the specified range. . The value obtained by subtracting the speed ratio K _i from 1 is a lower threshold m _2, which is initially set (if they meet the equation (3)) if it exceeds also determines that outside the specified range.
When the upper limit threshold m ₁ and the lower limit threshold m ₂ are set to the same number m, the absolute value of the value obtained by subtracting 1 from the calculated speed ratio K _i exceeds the initially set threshold value m ( (If the expression (4) is satisfied), it is determined that the value falls outside the specified range.

For example, in FIG. 2, the formula (4) is applied, the threshold value m (m ₁ , m ₂ ) is set so that m = 0.1, and the calculation range of the speed ratio K _i is a specified range based on 1. When the deviating numerical value is enclosed by an ellipse, it is determined that the wheel corresponding to the enclosed speed ratio K _i has a different diameter from the reference wheel T ₀ (T _RR ).
The different diameter determiner 42 is for determining whether other wheels have different diameters or the same diameter with respect to the reference wheel T ₀ (T _RR ).

m ₁ <K _i −1 (2)
m ₂ <1-K _i (3)
m <| K _i -1 | (4)

The different diameter wheel determination unit 43 is based on the information transmitted from the different diameter determination unit 42 that each wheel has a different diameter (small diameter or large diameter) or the same diameter with respect to the reference wheel T ₀ (T _RR ). Thus, which wheel (T _FR , T _FL , T _RR , T _RL ) corresponds to the different diameter wheel, that is, the position of the different diameter wheel is determined.

That different-diameter wheels determiner 43, the range of speed ratio _{K i} defined one by a threshold _{m (m} 1, _{m 2)} as a reference, the wheel outside the specified range as Equation (2) to (4) If the number of hits in (T) is 0, it is determined that there are no different diameter wheels (a-1). If the number of hits is one, the corresponding wheel is the only different diameter wheel. identified (a-2,3,5), wherein if the number of hits is three specified as is the reference wheel T ₀ is the only different-diameter wheel (a-4), the corresponding number of two In some cases, two applicable wheels (b-1, 4, 6) or two non-applicable wheels (b-2, 3, 5) are identified as different diameter wheels.

Furthermore, different-diameter wheels if limited to a small diameter, such as a temper tires and air leakage tire, in a case where the number of hits is determined to be two, is out of the specified range exceeds the upper threshold m ₁ If, when two wheels are true is identified as different diameter wheel (b-1, 4, 6), is out of the specified range than the lower limit threshold value m ₂ is not applicable Two wheels that are not present are identified as different diameter wheels (b-2, 3, 5).

Returning to FIG. 1, the description will be continued.
The straight traveling determination unit 50 determines whether or not the vehicle c travels straight. Specifically, the straight traveling determination unit 50 is based on information such as a steering angle sensor or a lateral G sensor (not shown), or based on the speed ratio K _i calculated by the speed ratio calculation unit 30. Or something. When it is determined by the straight travel determination unit 50 that the vehicle is not traveling straight, the different diameter wheel determination by the different diameter determination unit 40 is not performed. The reason is that the accuracy of the determination by the straight traveling determination unit 50 is higher when the vehicle is traveling straight.

The method for determining the straightness of the vehicle and the speed ratio K _i based on described with reference to FIG.
That is, the four-wheel wheels mounted on the vehicle are classified into either a group of the same-diameter wheels or a group of different-diameter wheels, and in each of the classified groups, the speed ratio _Ki is in a predetermined range. If it is within, the vehicle is going straight.
Incidentally, when the number of wheels that are classified in one of the groups is one wheel, since the speed ratio K _i to be compared in this group does not exist, in this case, the speed ratio Ki is a predetermined range in the other groups If it is within the range, it can be said that the vehicle c is traveling straight.
Specifically, the minimum value minK _i and the maximum value maxK _i are taken out of the speed ratios K _i of the wheels of each group according to the following equation (5), and the absolute value of the difference between the two is equal to or less than a specified value n. It can be determined that the values do not vary.

| MinK _i −maxK _i | <n (5)

Returning to FIG. 1, the description will be continued.
The determination display unit 60 displays information based on the determination result of the different diameter determination unit 40. Specifically, the determination display unit 60 is a display panel of a navigation system or voice guidance. Information to be displayed may indicate that different-diameter wheels are mounted on the vehicle, or may be the positions of wheels corresponding to the different-diameter wheels. In addition, when two different-diameter wheels are mounted on one side as shown in FIG. 2 (b-5, 6), it can be said that the running vehicle is in an unstable state. A display is also made.

Next, referring to FIG. 3 (appropriately FIG. 1), an execution routine of the different diameter wheel determination method according to the embodiment of the present invention will be described based on a flowchart.
First, the reference wheel selection means 35 selectively selects the reference wheel T ₀ from the four wheels T _i (T _FL , T _RL , T _RR , T _FR ) of the vehicle c (step 11 (hereinafter referred to as “step 11”). (Describe as S11)). Next, a threshold value setter 41 sets a threshold value m (m ₁ , m ₂ ) for different diameter discrimination (S12). Next, the wheel speed detection unit 20 detects the wheel speed ω _i for each of the four wheels T _i (T _FL , T _RL , T _RR , T _FR ) (S13). The next reference wheel speed omega ₀ of the reference wheel T ₀ which is selected for calculating the speed ratio K _i of wheel speed omega _i in the other wheel T _i (S14). Next, the calculated speed ratio _Ki is stored in the storage unit 36 (S15). Information of the stored speed ratio K _i is also used in the vehicle which will be described later linearity determined (S18).

Next, in the different diameter determination unit 40, whether or not the speed ratio K _i is outside the specified range based on 1 is executed for each wheel based on the inequalities exemplified in the expressions (2) and (3). and performs different diameters determined for the reference wheel _{T 0} (S16A, S16B). Note here that the order respectively the judgment upper threshold _{m 1} (S16A) and determination lower threshold _{m 2} (S16B) may be reversed.

When it is determined that “the wheels with different diameters” are present (S16A, S16B: Yes), a flag is set for the corresponding wheel (S17). At this stage, it is only determined whether or not the reference wheel T ₀ has a different diameter, and it cannot be determined whether or not the corresponding wheel is a different diameter wheel.
On the other hand, when the number of wheels whose speed ratio K _i is out of the specified range based on 1 is 0 (see formulas (2) and (3)), it is determined that “the wheel of different diameter does not exist”. (S16A, S16B: No), the process proceeds to a vehicle travel flowchart (S53: No) shown in FIG.

Returning to FIG. 3 (appropriately FIG. 1), the description will be continued.
Next, the straightness determination unit 50 determines the straightness of the vehicle c (S18). Note that the straightness determination may be performed using information such as a steering angle sensor or a lateral G sensor provided for another purpose in the vehicle, but the speed ratio K _i stored in step S15 described above is used. Sometimes it is done. Subroutine (S18) performing the straightness determined using the speed ratio K _i, with reference to FIG. 4 will be described in detail later.

  If it is determined that the vehicle is not traveling straight ahead (S19: No) in the subroutine (S18) for determining straightness, the flag is reset (S20), and any stage from the start to step S13 is performed. Return to. That is, the determination that one of the four wheels corresponds to a different diameter wheel is withdrawn. When the vehicle is turning, the determination accuracy of the different-diameter wheels is lowered, so this case is excluded.

If it is determined in the subroutine (S18) for determining the straight traveling performance that the vehicle is traveling straight (S19: Yes), the wheel corresponding to the different diameter wheel is determined by the different diameter wheel determination unit 43 based on the number of flags. (S21, S24, S26A, S26B).
That is, when the number of corresponding wheels whose speed ratio _Ki is out of the specified range based on 1 is 1 (see equations (2) and (3)), that is, when the number of flags is 1. (S21: Yes), it is specified that the wheel is the only different diameter wheel (S22).
Further, when the number of corresponding wheels out of the specified range with the speed ratio K _i being 1 is 3, that is, when the number of flags is 3 (S24: Yes), the reference wheel T ₀ is It is specified that it is the only different diameter wheel (S25).

And when the number of corresponding wheels out of the specified range with the speed ratio K _i as a reference is 2, that is, when the number of flags is two (S26A, S26B: Yes), it corresponds. It is determined that any one of the two wheels or the two wheels that are not applicable is a different diameter wheel (S27A, S27B).

Furthermore, if the different diameter wheels are limited to those having a small diameter such as a temper tire or an air leak tire, the positions of the two different diameter wheels can be specified.
In other words, if the number of hits of the wheel whose speed ratio K _i is out of the specified range based on 1 is 2, and it is determined that these are outside the upper limit threshold m ₁ ( S26A: Yes), it is specified that the two corresponding wheels are different diameter wheels (S27A).
In addition, when it is determined that the number of hits of the wheel whose speed ratio K _i is out of the specified range based on 1 is 2, and it is determined that these are outside the lower limit threshold m ₂ ( S26B: Yes), two wheels that are not applicable are identified as different diameter wheels (S27B).

  When the judgment flow in steps S26A and S26B is verified with reference to FIG. 2B, in the case of (b-1), (b-4), and (b-6) in the case of step S26A; Yes → S27A If step S26B; Yes → S27B, then (b-2), (b-3), and (b-5) apply.

The wheels determined to be different diameter wheels are displayed on the determination display unit 60 and a warning is given (S23).
Further, when there are two different diameter wheels, it is determined whether or not the two different diameter wheels are arranged on the same side of the vehicle c (S28). If the different-diameter wheels are not arranged on the same side, that is, if they are arranged on a diagonal line, a normal warning is given (S23). If the wheels with different diameters are arranged on the same side (S28: no), a heavy warning is displayed on the determination display unit 60 because the vehicle is in an unstable state where it is curved even if the vehicle is controlled to go straight. It is displayed (S29). This is the end of the different diameter wheel determination routine.

Next, with reference to FIG. 4, the subroutine for determining whether or not the vehicle is traveling straight at step S18 in FIG. 3 will be described. Wherein the vehicle straightness determination is conceptually and magnitude of the speed ratio K _i, which is calculated with reference to the matrix shown in FIG. 2 is based on whether they have a predetermined relationship, It is determined whether the vehicle is traveling straight or turning. Specifically, the flow is as follows.

First, a prescribed value n for straightness determination is set (S31). Next, the speed ratio K _i of the wheel with the flag set or not set among the four wheels of the vehicle is acquired from the storage unit 36 (S32). Then, flag calculates the maximum difference among the speed ratio K _i included in one of the group of the group of wheels is not a group or set of wheels is set (S33). Then the maximum difference of the computed speed ratio K _i with the relationship between the specified value n (Equation (5)), the straightness of the judgment of the vehicle is made (S34). Then, it is determined whether the vehicle is traveling straight or turning, and the process returns to the different diameter wheel determination routine (FIG. 3: S18) (S35, S36).

Next, with reference to FIG. 5, the positioning of the different diameter wheel determination routine S52 (see FIG. 3) in the main routine of vehicle traveling from when the ignition is turned on (IG-ON) to when the ignition is turned off (IG-OFF) will be described. To do.
First, the ignition is turned on (S51), and after the vehicle starts to travel, a different diameter wheel determination routine is entered after a while (see S52, FIG. 3). Here, if it is determined that wheels with different diameters are present (S53: Yes), the vehicle control mode is changed (S54). Specifically, the antilock brake control is released or other automatic travel control systems are released. The vehicle control mode change state is continued until the ignition is turned off (S55). That is, if the vehicle engine is stopped and the wheels with different diameters are replaced with normal wheels, thereafter, traveling in the normal vehicle control mode becomes possible.

By the way, even if it is determined that the different-diameter wheels are not present (S53: No), after stopping with the foot brake (S56: Yes), if the vehicle runs again without turning off the ignition (S57: No). The different diameter wheel determination routine (S52) is executed again. As a result, every time the vehicle starts after stopping, the determination of the different-diameter wheel is performed again.
Even if the running vehicle continues to run for a long time without stopping (S56: No), if the set time t has elapsed from the previous determination of the different-diameter wheel (S52), the different-diameter wheel determination routine (S52). ) Will be executed. As a result, for example, when traveling continuously for a long distance, it is possible to detect the situation even if air leakage from the wheels occurs.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the summary of this invention.

It is a block diagram which shows the structure of the different diameter wheel determination apparatus which concerns on embodiment of this invention. (A) is a table showing a case one wheel of the four wheels are different-diameter wheel, the speed ratio K _i of the wheel speed of each wheel, (b) the two wheels of the four wheels are different diameter when it is a wheel, a table showing speed ratio K _i of the wheel speed of each wheel. It is a flowchart which shows the execution routine of the determination method of the different diameter wheel which concerns on embodiment of this invention. It is a flowchart which shows the subroutine of the straight-advancing determination step of the vehicle in the different diameter wheel determination method which concerns on this embodiment. It is a flowchart which shows the positioning of the execution routine of the determination method of the different diameter wheel which concerns on this embodiment in the main routine of driving | running | working of a vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Different diameter wheel determination apparatus 20 Wheel speed detection part 30 Speed ratio calculation part 35 Reference | standard wheel selection means 36 Memory | storage part 40 Different diameter determination part 41 Threshold setting device 42 Different diameter determination device 43 Different diameter wheel determination device 50 Straightness determination part 50 60 judgment display section _{K i (K FL, K RL} , K RR, K FR) speed ratio _{S i (S FL, S RL} , S RR, S FR) sensor T ₀ reference wheel _{T i (T FL, T RL} , _{T RR,} T _FR) wheel c vehicle _m, m _1, m ₂ threshold n specified value

Claims (12)

A method for determining different diameter wheels for determining wheels of different diameters among four wheels of a vehicle equipped with four wheels,
Detecting wheel speed for each said wheel of four wheels;
Calculating a speed ratio of wheel speeds in other wheels based on a wheel speed of a reference wheel that is alternatively selected from the four wheels;
Determining whether the calculated speed ratio is outside a specified range based on 1;
When the number of applicable wheels out of the specified range is 0, it is determined that there are no different diameter wheels,
If the number of corresponding wheels out of the specified range is 1, specify that the wheel is the only wheel of different diameter,
If the number of hits outside the specified range is three, specify that the reference wheel is the only wheel of different diameter,
Conditional speed of the wheel deviates the specified range is two, the step of two wheels that is not two wheels or corresponding are applicable are specified as being different-diameter wheel seen including,
When the number of the wheels out of the specified range is two, when the two different diameter wheels are not arranged on the same side of the vehicle, a warning is normally given and the two different diameters are provided. A method for determining different diameter wheels, wherein a heavy warning is given when the wheels are arranged on the same side of the vehicle . The method for determining different diameter wheels according to claim 1, wherein the determination of whether or not out of the specified range is:
When a value obtained by subtracting 1 from the speed ratio exceeds an initially set upper limit threshold, it is determined that the value falls outside the specified range;
A method for determining a different-diameter wheel, wherein a value obtained by subtracting the speed ratio from 1 exceeds a predetermined lower limit threshold, and is determined to be out of the specified range. In the determination method of the different diameter wheel of Claim 2,
If the number of hits of the wheel determined to exceed the upper limit threshold and deviate from the specified range is two, specify that the two corresponding wheels are different diameter wheels,
When the number of hits of the wheels determined to exceed the lower limit threshold and deviate from the specified range is two, it is specified that the two non-corresponding wheels are different diameter wheels. Judgment method for different diameter wheels. In the determination method of the different diameter wheel of any one of Claims 1-3,
Further comprising determining whether the vehicle is traveling straight;
When it is determined that the vehicle is not traveling straight, the determination of the different-diameter wheel is not executed. In the determination method of the different diameter wheel of Claim 4,
The step of determining that the vehicle is traveling straight is performed based on the calculated speed ratio. In the determination method of the different diameter wheel of any one of Claims 1-5,
When the vehicle stops, determination of different diameter wheels is executed every time the vehicle starts after stopping. In the determination method of the different diameter wheel of any one of Claims 1-6,
Even if it is determined that the different-diameter wheel is not present during the running of the vehicle, the determination of the different-diameter wheel is performed again after a set time has elapsed. . It is a different diameter wheel determination device for determining different diameter wheels among four wheels of a vehicle equipped with four wheels,
A wheel speed detector for detecting a wheel speed for each of the four wheels;
A speed ratio calculation unit that calculates a speed ratio of wheel speeds in other wheels based on a wheel speed of a reference wheel that is alternatively selected from the four wheels;
A different diameter judging device for judging whether or not the calculated speed ratio is out of a specified range based on 1.
If the number of applicable wheels out of the specified range is zero, it is determined that there are no different diameter wheels, and if the number of applicable wheels out of the specified range is one, that wheel is the only different wheel. If the number of corresponding wheels out of the specified range is specified as three wheels having a diameter, the reference wheel is specified as the only different diameter wheel, and the number of corresponding wheels out of the specified range is specified. If the number of wheels is two, the different diameter wheel discriminator for identifying that the two corresponding wheels or the two not corresponding wheels are different diameter wheels,
When the number of the wheels out of the specified range is two, when the two different diameter wheels are not arranged on the same side of the vehicle, a warning is normally given and the two different diameters are provided. A determination display unit for determining whether or not a wheel is located on the same side of the vehicle, and a determination display unit for performing a heavy warning . The determination as to whether or not the specified range in the different diameter determiner of the different diameter wheel determination device according to claim 8 is,
If the value obtained by subtracting 1 from the speed ratio is larger than the initially set upper limit threshold, it is determined that the value falls outside the specified range.
An apparatus for determining different-diameter wheels, wherein when the value obtained by subtracting the speed ratio from 1 is larger than an initially set lower limit threshold, it is determined that the value falls outside the specified range. The different diameter wheel determination device of the different diameter wheel determination device according to claim 9,
If the number of hits of the wheel determined to exceed the upper limit threshold and deviate from the specified range is two, specify that the two corresponding wheels are different diameter wheels,
When the number of hits of the wheels determined to exceed the lower limit threshold and deviate from the specified range is two, it is specified that the two non-corresponding wheels are different diameter wheels. Judgment device for different diameter wheels. In the different diameter wheel determination apparatus according to claim 9 or 10,
If the vehicle further includes a straightness determination unit that determines whether the vehicle is traveling straight, and the straightness determination unit determines that the vehicle is not traveling straight, the determination by the different-diameter wheel determination unit is executed. An apparatus for determining different-diameter wheels, characterized by not being performed. In the different diameter wheel determination apparatus according to claim 11,
The straight-ahead determining unit makes a determination based on the speed ratio calculated by the speed ratio calculating unit.

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