JP3155154B2 - Wheel information estimation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel information estimating apparatus for estimating information on a wheel based on the rotational speed of the wheel, and more particularly, to a method for estimating the accuracy of estimation due to a periodic disturbance mixed in a detected value of a wheel speed. The present invention relates to a technique for suppressing the reduction.

[0002]

2. Description of the Related Art The wheel information estimating device generally includes (a) a detecting device for detecting a rotational speed of a wheel, and (b) estimating means for estimating information on a wheel based on a value detected by the detecting device. It is configured as follows.

One type of the wheel information estimating apparatus is disclosed in
-133831. This is to estimate the tire air pressure as information about the wheel based on the frequency of the one whose intensity is substantially maximum within a set frequency range among a plurality of frequency components of the rotational speed detected by the detection device, It is estimated that the lower the frequency, the lower the tire pressure.

[0004]

The present applicant has conducted research on the wheel information estimating apparatus, and as a result, has obtained the following facts. The values detected by the detection device include periodic disturbances based on the tire non-uniformity of the wheels, etc. If the periodic disturbances are left as they are, the effects of the periodic disturbances appear in the estimation values by the estimation means. As a result, the fact that the estimation accuracy may be reduced has been obtained. In order to eliminate the periodic disturbance mixed in the detection value, the present applicant sets the wheel information estimation device including the detection device and the estimating means as a correction target for the detection value and the periodic disturbance mixed in the detection value. It has been proposed to add a detection value correction means for correcting the detection value so as to be removed.

However, the detection value correcting means specifically removes the periodic disturbance by utilizing the periodicity of the periodic disturbance and using the detection values acquired during a plurality of rotations of the wheel. It is. Therefore, there is a problem that it takes time until the correction error by the detection value correction means becomes equal to or less than the allowable value, and during that time, it is inevitable that the estimation accuracy deteriorates due to the periodic disturbance mixed into the detection value.

In view of such circumstances, the invention of claim 1 pays attention to the fact that an estimation error due to a periodic disturbance mixed in a detection value is strongly related to a traveling state of a vehicle, and calculates an estimation value instead of a detection value. An object of the present invention is to make it possible to suppress a decrease in estimation accuracy due to a periodic disturbance even before the operation of the detection value correcting means is completed, by using the estimated value correcting means for correction together with the detection value correcting means.

A second aspect of the present invention is based on the first aspect of the invention, which focuses on the fact that, among the driving conditions of the vehicle, the elements of the vehicle body speed and the degree of road surface irregularity are strongly related to the estimation error due to the periodic disturbance. An object of the present invention is to make it possible to effectively execute an estimated value correction based on a traveling state of a vehicle.

According to a third aspect of the present invention, there is provided a wheel information estimating apparatus in which the estimated value correcting means according to the first or second aspect of the present invention is used in combination with the detected value correcting means. The purpose of this is to avoid the situation of doing so.

[0009]

In order to solve each of the problems, the invention of claim 1 is directed to a wheel information estimating apparatus including the detecting device 1 and the estimating means 2 as conceptually shown in FIG. (A) The value detected by the detection device 1 is
And correct so that the periodic disturbance mixed into the
Detection value correction means 3 to be supplied to the determination means 2, and (b) estimation means
2 is added to the detected value based on the running condition of the vehicle.
The value detected by the detector 1 without being removed by the corrector 3
And an estimated value correcting means 4 for correcting the influence of the periodic disturbance remaining in the estimated value to not appear in the estimated value.

[0010] Incidentally, "estimating means 2" for example, as described in the publication, the maximum intensity is substantially within the set frequency range out of a plurality of frequency components of the rotational speed detected by the detection device 1 The tire pressure of the wheel can be estimated as wheel information based on the frequency of the following.

[0011] "estimated means 2" is also, at least (a),
From a wheel information basic value, which is a basic value of wheel information, and a rotation speed detected by the detection device, a disturbance observer that estimates a disturbance to the wheel, and (b) based on the estimated disturbance,
It is also possible to adopt a form including a wheel information change amount estimating unit that estimates a change amount of the wheel information actual value, which is the actual value of the wheel information, from the wheel information base value. This format will be described in detail in an embodiment.

[0012] It should be noted that, here in the definitive "detection value correcting means 3"
As described above, utilizing the periodicity of the periodic disturbance, it is possible to remove the periodic disturbance by using a detection value obtained during multiple rotations of the wheel, for example, The following embodiment can be adopted. That is, among a plurality of past rotational speeds determined in order based on the periodic signal from the detection device, a rotational speed having a predetermined relationship with the rotational speed determined this time is added to or subtracted from the rotational speed determined this time. Operations that include
A mode in which periodic disturbance mixed in the rotation speed is removed can be adopted.

[0013] In more detail, each time a sampling cycle set in advance has elapsed, at least calculated based on the periodic signal from the detection device during 1
A sample rotation speed calculation unit that calculates the average value of the original rotation speeds as the sample rotation speed, a sample fluctuation rotation speed calculation unit that calculates the fluctuation component of the sample rotation speed calculated this time as the sample fluctuation rotation speed, and An error value representing a periodic change of the power periodic disturbance (which removes the periodic disturbance mixed in the variable rotational speed by adding to the variable rotational speed) is associated with at least one rotation of the wheel and the rotational position of the wheel. One rotation memory for storing,
Every time the sampling period elapses, at least one error value obtained just before one rotation of the wheel from the current sample variation rotation speed is read from the memory for one rotation as an old error value group, and the average of the old error value group is read. The output value calculation unit calculates the sum of the average old error value, which is the current value, and the current sample fluctuation rotation speed to obtain an output value, and outputs the sum of the output value and the fixed component of the sample fluctuation rotation speed to the final rotation. A final rotation speed calculation unit that calculates the speed, and a subtraction of the current output value from an average old error value obtained just before one rotation of the wheel from the current sampling fluctuation rotation speed, thereby obtaining the new error value of the current time. An error value calculator for calculating,
In this case, the rotation memory may include a one-rotation memory updating unit that updates all the values of the old error value group at this time with the calculated new error value.

The "wheel information" here can be selected, for example, from tire pressure, radius, inertia moment, spring constant, damper coefficient, ground contact, cornering power, and the like.

According to a second aspect of the present invention, in the first aspect of the present invention, the estimated value correcting means 4 determines the correction amount of the estimated value by the estimating means 2 to be larger when the vehicle speed as the traveling condition is high and when the vehicle speed is small. And when the road surface unevenness degree as the running condition is low, the determination is made larger when the road surface unevenness degree is high.

A third aspect of the present invention is the invention according to the first or second aspect, further comprising a detection step as conceptually shown in FIG.
By the detection device 1 without being removed by the output value correction means 3
Estimated value correction permitting / prohibiting means 5 for permitting the correction by the estimated value correcting means 4 while the periodic disturbance remaining in the detected value is larger than the allowable value, and prohibiting the correction when the periodic disturbance is less than the allowable value is provided. I do.

[0017]

In the wheel information estimating apparatus according to the first aspect of the present invention,
TheThe detection value correction means 3 converts the detection value into the
Correction to eliminate periodic disturbances,Detection value
Estimation errors due to mixed periodic disturbances may cause
Paying attention to the fact that they are strongly related,4
Calculates the estimated value by the estimating means 2 based on the traveling state of the vehicle.
Correct,Periodic outflow mixed with the value detected by the detection device 1
Estimate the effect of disturbanceNot to appear inI do.

According to the research of the present applicant, it has
In the state where the periodic disturbance is not sufficiently removed from the detected value
The higher the vehicle speed, the greater the estimation error.
Also, the lower the road surface roughness, the greater the estimation error
Turned out to be prone. The higher the vehicle speed, the better
In addition, the lower the degree of unevenness of the road surface, the more the periodic disturbance
Therefore, the ratio of the error value due to is increased. There
In the wheel information estimating device according to the second aspect of the present invention,
Is the estimated value correction means4Is the complement of the estimated value by the estimating means 2.
When the vehicle speed is high with the positive amount as the driving situation
Deciding bigger when small and running
When the road surface roughness is low or high
Make at least one of
U.

Since the "estimated value correcting means 4 " in the first or second aspect of the present invention is generally adapted to correct the estimated value based on the running condition of the vehicle in an open loop manner, the correction speed (correction error is corrected). This is advantageous in that it is easy to improve the correction accuracy (equivalent to the time required to reduce the value to the allowable value), but has the disadvantage that it is difficult to sufficiently increase the correction accuracy. On the other hand, the detection value correction means 3 uses, for example, the periodicity of a periodic disturbance,
In the case of removing the periodic disturbance by using the detection value obtained during the rotation of the wheel a plurality of times,
There is an advantage that it is easy to sufficiently increase the correction accuracy, but there is a disadvantage that it is difficult to improve the correction speed. In short, the estimated value correcting means 4 and the detected value correcting means 3 have a relationship in which one of the disadvantages is used as the other advantage. , It is possible to sufficiently increase the correction accuracy while suppressing the decrease.

However, when both correction means 3 and 4 are used together, the following problem occurs. That is, if the estimated value correcting means 4 may operate even after the operation of the detected value correcting means 3 is completed, the estimating means 2 based on the detected value from which the periodic disturbance has been sufficiently removed by the detected value correcting means 3 .
Value correction means for the estimated value estimated by
4 acts, and the operation of the detection value correction means 3 and the operation of the estimation value correction means 4 interfere with each other, and the estimation accuracy is rather reduced.

In order to solve this problem, the invention of claim 3 has been made for a wheel information estimating apparatus of a type using both the detected value correcting means 3 and the estimated value correcting means 4. In the information estimation device, the estimation value correction permission / prohibition unit 5 is not removed by the detection value correction unit 3.
The periodic disturbance remaining in the value detected by the detection device 1
That is, while the correction error is larger than the allowable value, the estimated value correcting means 4
Is permitted, and is prohibited after the value becomes equal to or less than the allowable value.

[0022]

As is apparent from the above description, according to the first aspect of the present invention, the detection value correcting means and the estimated value correcting means
Are used together, so the disadvantages of one of them are the advantages of the other.
Compensation, thereby compensating while suppressing a decrease in compensation speed.
The effect is obtained that the accuracy can be sufficiently increased .

According to the second aspect of the present invention, the estimated value is corrected on the basis of at least one of the vehicle speed and the degree of road surface unevenness, which are factors strongly related to the estimation error due to the periodic disturbance in the running condition of the vehicle. Therefore, it is possible to effectively execute correction of the estimated value based on the traveling state of the vehicle.

According to the third aspect of the present invention, the detection value correcting means and the estimated value correcting means are used in combination.
Therefore, the mutual interference between the two correction means is avoided, and the effect of ensuring the appropriate correction is obtained.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on the illustrated embodiments. In FIG. 2, reference numeral 10 denotes a rotor, and 12 denotes an electromagnetic pickup. The rotor 10 is a wheel 14 shown in FIG.
, And has a number of teeth 16 on the outer circumference. The electromagnetic pickup 12 generates a voltage that changes periodically as the teeth 16 pass. This voltage is shaped into a rectangular wave by the waveform shaper 18 and supplied to the I / O port 22 of the computer 20. Wheel 14 is 4
And each electromagnetic pickup 1 provided on them.
2 are all connected to a computer 20 via a waveform shaper 18, but only one set is typically shown in FIG.

The wheel 14 is, as shown in FIG.
4 is a tire-equipped wheel having a tire 26 mounted on the outer periphery thereof. As shown in FIG. 4, it is considered that a rim side portion 28 and a belt side portion 30 that are relatively rotatable are connected by a torsion spring 32. Can be. Since the rotor 10 is mounted so as to rotate integrally with the wheel 24, the electromagnetic pickup 12 detects the angular velocity of the rim side portion 28 strictly.

As shown in FIG. 2, the computer 20 has a CPU 40 as a processing device and a ROM as a first storage device.
1 and a RAM 44 serving as a second storage device. The ROM 42 stores various control programs including a rotational speed calculation / correction routine shown in the flowchart of FIG. The side rotation speed calculation / correction unit 45 is configured. This computer 20 is connected to another computer 47. The computer 47 includes a CPU 48 as a processing device, a ROM 49 as a first storage device, a RAM 50 as a second storage device, and an I / O port 51 as an input / output device.
The ROM 49 stores various control programs such as an estimated value correction routine shown in the flowchart of FIG. 18 so that the disturbance observer 52, the correlation calculator 54, and the normalizer shown in FIG. 56, a spring constant change rate estimating unit 58, an estimated value correcting unit 60, and an abnormality determining unit 62.

A display device 66 is connected to the I / O port 51 of the computer 47 to notify the driver of the result of the determination made by the abnormality determining section 62. The display device 66 is a liquid crystal display in the present embodiment, but it is also possible to use another display device such as a lighted or flashing lamp, and various forms including a voice notification device that notifies the driver by voice. It is possible to employ a notification device.

The I / O port 51 of the computer 47 is further provided with a driving / braking torque for detecting a driving / braking torque applied to the wheel 24 (rim side portion 28) by a strain gauge or the like attached to a shaft of the wheel 24. The detection device 68 is connected.

The I / O port 51 is further connected to a vehicle speed sensor 70 and a road surface unevenness sensor 72, respectively. The vehicle speed sensor 70 may be, for example, a Doppler system that detects the ground vehicle speed using the Doppler effect of waves or a rotation speed utilization system that estimates the vehicle speed based on four rotation speeds v. Road surface unevenness sensor 7
2, for example, reads a signal affected by the road surface unevenness R and detects the PP value thereof as the road surface unevenness R, or detects the frequency characteristic of the rotation speed signal as the road surface unevenness R. can do. As a signal affected by the road surface unevenness R, for example, a signal representing the road surface unevenness R indirectly, such as a rotation speed signal, a vertical acceleration signal of a vehicle spring upper portion, a vertical acceleration signal of a vehicle lower spring portion, or the like, is selected. It is possible to select a signal that directly indicates the road surface unevenness R, such as a reflected signal.

The rim side rotational speed calculating / correcting unit 45 is based on rectangular wave signals (hereinafter also referred to as pulse signals) supplied from the electromagnetic pickups 12 and the waveform shaper 18 corresponding to the four wheels 14. The rotation speed of each wheel 14 is calculated, and the rotation speed of each wheel 14 is corrected by a signal delay / superposition process described later. Manufacturing and assembly errors are present in each wheel 14 and rotor 10, and periodic errors in rotational speed occur due to these errors and the like.
The rotation speed excluding the inherent rotation speed error unique to each wheel 14 is obtained. FIG. 6 shows that the vehicle speed V is 120
[Km / h], an example of frequency characteristics (relation between frequency and power spectrum) of a rotation speed signal acquired under a running condition in which a tire radius is about 330 [mm] and a tire air pressure is 0.2 [MPa]. Is represented by a graph. As is clear from the graph, a plurality of harmonics having a fundamental frequency of about 16 [Hz] are generated, which is a natural rotational speed error of the wheel 14, that is, a periodic disturbance. The correction is made. That is, in the present embodiment, the inherent rotational speed error of the wheel 14 is a periodic disturbance to be removed.

The rotational speed of the wheel 14 is calculated from the peripheral speed. For this, a substantial radius of the tire 26 (the distance from the road surface to the center of the wheel 14 when the tire is deformed by the load) is required. Which depends on the air pressure of the tire 26. Therefore, at first, the normal radius when the air pressure is normal is used. However, if the air pressure change of the tire 26 is found by the processing described later, the air pressure change is obtained from the tire diameter table stored in the ROM 42 in advance. Is read and used. When the rotational speed is calculated based on the angular velocity, the tire diameter table is not required.

The function of the rim side rotation speed calculation / correction section 45 is fulfilled by executing the rotation speed calculation / correction routine shown in FIG. 5. First, the principle will be described. The disturbance entering the rotation speed has a periodicity of making one rotation with the wheel 14. Therefore, by utilizing this periodicity, the periodic disturbance is removed by delaying the preceding portion of the temporal change in the rotational speed by exactly one cycle and superimposing it on the subsequent portion. The transfer function of the signal delay / superposition process can be represented by the block diagram of FIG. 7, and the state equation in this case is obtained by using the z variable.

[0034]

(Equation 1)

## EQU1 ## Here, V: body speed as input v: rotation speed as input y: rotation speed as output L: delay amount described in units of sampling period T of rotation speed v

In the figure, the delay calculating section delays the old error value e ₂ by the delay amount L (L sampling cycles T), adds it to the input error value e (= V−y), and By obtaining the error value e ₁ , the function of extracting the variable component is obtained by relatively emphasizing the variable component (that is, the periodic disturbance to be removed) at the input v.

Transfer function H from input v to output y
₁ (z) is

[0038]

(Equation 2)

## EQU1 ## Here, in order to obtain the frequency response H ₁ (ω) of the transfer function H ₁ (z), z ⁻¹ = e ^−jwn is set. Here, j: imaginary unit ω _n : normalized angular frequency Note that the normalized angular frequency ω _n is not the actual angular frequency ω _A described in units of 1 second, but the angular frequency described in units of the sampling period T. It is. Therefore, the normalized angular frequency omega _n is expressed by ω _n = ω _A T.

As a result, the frequency response H ₁ (ω) becomes

[0041]

(Equation 3)

Is obtained as follows. This frequency response H
The square of the absolute value of ₁ (ω) is

[0043]

(Equation 4)

Is as follows. As is clear from this equation, cos
ω_nL = 1, that is, ω_nL = 2nπ (n: integer)
Frequency response H₁(Ω) is 0, that is, input v is output
It is in a state that does not appear at all in y. Also, the frequency response H
₁Multiple angular frequencies ω where (ω) is 0 _nNext to each other
The median value of two touching objects (ω_nEach ward where L ≠ 2nπ
Input point v at the output y
, For example, ω_nL = (2n
+1) Frequency response H at π₁The absolute value of (ω) is 1
Must use the input v as it is
Then

[0045]

(Equation 5)

## EQU1 ## Therefore, instead of having to utilize the input v, it | 1-g / 2 | and the use of consisting adjustment gain as a value v ₁ obtained by multiplication.

As described above, the transfer function H from the input v to the output y is
_{Although 1} (z) has been described, the output y is affected not only by the input v but also by the input V. Then, output y
In order to evaluate the effect of the input V in the above, the transfer function H ₂ (z) from the input V to the output y is also determined. This transfer function H ₂ (z) is obtained in the same manner as the transfer function H ₁ (z),

[0048]

(Equation 6)

Is as follows. The frequency response H ₂ (ω) of this is

[0050]

(Equation 7)

The square of the absolute value of the frequency response H ₂ (ω) is

[0052]

(Equation 8)

Is as follows. As is clear from this equation, ω _n
When L = 2nπ, the absolute value of the frequency response H ₂ (ω) is 1
And consequently V = y. That is, the output y can be approximately expressed by the following equation: y = H ₁ (z) v ₁ + H ₂ (z) V. When ω _n L ≠ 2nπ, y = v ₁ and ω _n L = When 2nπ, y = V. Here, when the input v ₁ is considered as being separated into a fixed component (also referred to as an offset value) v ₀ which is the center of the temporal variation and a variation component Δv, the offset v ₀ should originally match the input V. Therefore, when ω _n L ≠ 2nπ, y = v ₀ + Δv ₁ , and when ω _n L = 2nπ, y = v ₀ .

Therefore, assuming that the fixed component v ₀ is 0,
If the fluctuation component Δv is used as the input v _{1 and} 0 is used as the input V, the output y becomes Δv, which is a physical quantity representing the temporal change of the periodic disturbance to be obtained. Also after
As described in [0073], the period
If the fixed component v _0, ie, the offset value, is added to the output y, ie, the fluctuation component Δv, from which the target disturbance has been removed, the rotation speed v, from which the periodic disturbance has been removed, is obtained.

As described above, since the relationship of ω _n L = 2nπ holds for the delay amount L, the delay amount L is represented by L = (2nπ) / ω _n . Here, if n = 1, then L = (2π) / ω _n , and, as described above, the relationship of ω _n = ω _A T is established. The fundamental frequency f _1, which is the frequency of the fundamental wave of the periodic disturbance to be removed, is represented by 1 / f ₁ = (2π) / ω _A. Here, f ₁ = V / (2πR). Therefore, the delay amount L is represented by L = (1 / f ₁ ) / T.

This equation is physically expressed as "the delay amount L is the number of times the rotation speed v is sampled while the periodic disturbance to be removed advances one cycle, that is, while the wheel 14 makes one rotation. Is equal to ”.

The tire radius R is about 330 [mm], and the vehicle speed is
When V is 120 [km / h], the fundamental frequency f₁But
Approximately 16 [Hz], and the sampling period T is 5
[Ms], the delay amount L in this case is about 12 [sample
Ring cycle]. FIG. 8 shows that L = 12 and g = 0.4.
Transfer function H₁Graph of frequency characteristics of (z)
Represent. In this graph, the vertical axis represents the frequency response H₁(Ω) is dB
Frequency response H₁(Ω) is 1
That is represented by 0 in the graph, and the frequency response H
₁The fact that (ω) is 0 is represented by -∞ in the graph.
And Therefore, as is clear from the graph, 1
6 [Hz] is the fundamental frequency f₁Multiple harmonics occur
Frequency response H at each frequency position₁(Ω) is enough
And the frequency response at each other position
H₁(Ω) is sufficiently close to 1.

Next, a description will be given of a specific technique for implementing a rotational speed calculation / correction technique using a computer according to this principle.

First, a brief description will be given. Each time each pulse (each unit wave constituting a series of rectangular signals, which is a rectangular wave) is supplied from the electromagnetic pickup 12, the original rotational speed v is sequentially calculated based on the time interval between each pulse. As the time interval of each pulse, for example, a rising interval time, a falling interval time, and a pulse midpoint interval time of each pulse can be selected.

Every time one sampling period T elapses, an average value of at least one original rotation speed v input and calculated during that period is calculated as a sample rotation speed v. Further, the average value is calculated from the sample rotation speed v calculated in the past and the current sample rotation speed v. This average value is used as the offset value, and the offset value is subtracted from the current sample rotation speed v to obtain the sample variation rotation speed Δv (“v” in FIG. 7).
Is required).

The RAM 44 is provided with a memory for one rotation. The memory for one rotation stores an error value E (corresponding to “e (= V−y)” in FIG. 7) in association with each tooth of the rotor 10. The error value E is a value representing a periodic disturbance to be removed, that is, a state in which the disturbance caused by the non-uniformity of the wheels changes with the rotation of the rotor 10 in this embodiment. Will be described. The memory for one rotation is provided with the same number of storage addresses as the number of pulses output from the electromagnetic pickup 12 during one rotation of the rotor 10, that is, the number of teeth of the rotor 10, and each error value E is assigned to each storage address. Are sequentially stored.

FIG. 9 conceptually shows the structure of the memory for one rotation, taking as an example the case where the rotor 10 has eight teeth. In the figure, “1-1” indicates an error value E calculated first during the first rotation, and “1-2” indicates an error value E calculated second during the first rotation. , "2-1" indicates the error value E calculated first during the second rotation, and the left-hand number of the two numbers connected by a hyphen indicates the number of rotations of the wheel 14 , And the number on the right side indicates the number of each pulse in each rotation.

Every time the sampling period T elapses, the error value E is read from the memory for one rotation. At least one error value E already stored in the memory for one rotation
Among them, the error value group E in which each of the at least one variable rotational speed Δv relating to the current sample variable rotational speed Δv and the pulse generation rotational position of the rotor 10 are common is read.
That is, the error value group E obtained just before the rotation of the rotor by one rotation from the current sample fluctuation rotation speed Δv is read as the old error value group E. An average value is obtained for the read old error value group E, and the average old error value E _MEAN is obtained.
(Corresponding to “e ₂ ” of the delay calculation unit in FIG. 7).

For example, referring to the example of FIG. 9, assuming that two variable rotation speeds Δv can be obtained in each sampling, as shown in FIG.
“1-1” and “1-2” in FIG. 9 are “1-”,
That is, the first old error value group E during the first rotation
And the average value of the two old error values E respectively indicated by “1-1” and “1-2” is set as the average old error value E _MEAN indicated by “1-”. Further, assuming that four variable rotation speeds Δv are obtained in each sampling, for example, as shown in FIG.
"1" to "1-4" constitute "1-", that is, a first old error value group E at the time of the first rotation, and "1-1".
The average value of the four old error values E respectively indicated by .about. "1-4" is defined as the average old error value _E.sub.MEAN indicated by "1-".

The product of the current average old error value E _MEAN thus obtained and the gain g is obtained.
The current sample fluctuation rotation speed Δv and the adjustment gain | 1
Product with −g / 2 | (corresponding to “v ₁ ” in FIG. 7)
Is also required. Further, the sum of the two products is calculated, and the result is taken as the output y in FIG. That is, the output y
Is obtained as old E _MEAN · g + sample Δv · | 1-g / 2 |. By adding the offset value to the output y, the final rotational speed v is obtained.

The current output y and the current average old error value E _MEAN
From the new error value E (“e ₁ ” of the delay calculation unit in FIG. 7)
Is required). That is, the new error value E is e + e ₂ = (V−y) + e ₂ = (0−y) + e ₂ = −y
+ It is required as an old E _MEAN .

When the new error value E is obtained, the error value E is updated in the memory for one rotation. That is,
Each of the old error values E constituting the current old error value group E is rewritten to the same new error value E.

With reference to the example of FIG. 9, for example,
When the new error value E corresponding to “2-” is calculated, “1” constituting the old error value group E indicated by “1-”
The old error values E indicated by “−1” and “1-2” are both rewritten to the same new error value E.

However, the error value E stored in the memory for one rotation is obtained by repeating the above processing many times.
, Accurately reflects the periodic disturbance to be removed, the output y becomes 0, and the new error value E becomes the old error value E. Therefore, the error value E is rewritten at this stage. In this case, the error value E is substantially fixed.

Here, the relationship between the memory for one rotation and the delay amount L will be described. In the present embodiment, the calculation of the original rotation speed v is performed every time each pulse is generated. However, the calculation of the sample fluctuation rotation speed Δv, the calculation of the average error value E _MEAN ,
The calculation of the output y and the calculation of the final rotational speed v are performed not every pulse but every time the sampling period T elapses. Therefore, the memory for one rotation has substantially the same number of error values E (four in the example of FIG. 10 and two in the example of FIG. 11) as the number of pulses sampled during one rotation of the wheel 14. It can be said that it is a memory to be stored.

In this embodiment, when the previously calculated original rotational speed v is delayed by one rotation of the rotor and then superimposed on the original calculated rotational speed v, the delay amount is 1
The number is equal to the number of error value groups E stored in the rotation memory (that is, the number of sample fluctuation rotation speeds Δv).

In the description of the above theory, the amount of delay L is represented by L = 2πR / V / T using the sampling period T as a unit, and the sampling period T is unchanged. Therefore, in order to remove the periodic disturbance using its periodicity, it is necessary to change the delay amount L according to the vehicle speed V, that is, the rotation speed v. On the other hand, in the present embodiment, as described above, the number of memories for one rotation is the same as the number of teeth of the rotor 10, and the memory is always the latest
The error value E for the rotation is stored. Moreover,
Each time the sampling period T elapses, the average value of at least one error value E calculated during the sampling period T is obtained and used as the only representative value. Sampling period T
The division is performed in accordance with the number of the original rotational speeds v obtained each time. As a result, the division number is equal to the delay amount L. Therefore, in the present embodiment, the delay amount L can be automatically changed according to the rotation speed v by one delay calculation unit without providing a delay operation unit having a different delay amount L for each rotation speed v. become.

After the output y from which the periodic disturbance has been removed is calculated as described above, the final rotational speed v from which the periodic disturbance has been removed can be obtained by adding the offset value to the output y. Is calculated.

FIG. 12 is a graph showing two examples of the temporal change of the variable rotation speed Δv. The upper graph shows an example of a temporal change when the rotation speed v is slow, and the lower graph shows an example of a temporal change when the rotation speed v is fast. Comparing these graphs, as the rotation speed v increases, the number of variable rotation speeds Δv stored in the memory for one rotation during one sampling (in FIG.
It is also found that the number of the variable rotation speed groups Δv corresponding to one delay amount L decreases as the rotation speed v increases.

The contents of the rotation speed calculation / correction technique have been described briefly above. Next, the rotation speed calculation / correction routine of FIG. 5 will be specifically described.

First, in step S51 (hereinafter simply referred to as S51
Expressed by In the other steps as well, the value of the integer i is initialized to 1, and then, in S52, a state of waiting for the start of the current sampling cycle is set.
If the current sampling cycle has started, it is determined in S53 whether or not the current sampling cycle has ended. Since this time has just been started, the determination is NO, and the flow waits for the electromagnetic pickup 12 to output the i-th pulse in S54. If so, the determination is YES, the duration of the pulse is measured in S55, and the i-th original rotational speed v _(i) is calculated based on the duration in S56. That is, the part that executes S56 of the computer 20 constitutes the “original rotational speed calculation unit”. The calculated value is stored in the memory for one sampling of the RAM 44.

Thereafter, in S57, the value of the integer i is 1
It is increased, in S58, the current value of the integer i whether exceeds the maximum value i _MAX is determined. Since the maximum value _iMAX is set to the same value as the number of teeth of the rotor 10, this determination is eventually YES every time the original rotation speed v _{(i) for} one rotation is obtained. This time, if it is assumed that the current value of the integer i does not exceed the maximum value i _MAX , the determination is N
The result is O, and the process immediately returns to S53. However, if the value is exceeded, the determination becomes YES, and the process returns to S53 after the value of the integer i is reset to 1 in S66.

Thereafter, if the current sampling period ends while the execution of S53 to S58 and S66 is repeated, the determination in S53 becomes YES, and the process proceeds to S59 and subsequent steps.

In S59, the average value of the original rotational speed v obtained during the current sampling period and stored in the memory for one sampling is calculated, and is set as the sample rotational speed v. That is, this S of the computer 20
That is, the “sample rotation speed calculation unit” is constituted by the part that executes step 59.

In S60, the average value is calculated from the sample rotation speed v obtained in the past and the current sample rotation speed v, and this is set as the offset value. further,
By subtracting this average value from the current sample rotation speed v, the current sample rotation speed is calculated as Δv. That is, the portion that executes S60 of the computer 20 constitutes a “sample variation rotation speed calculation unit”.

It is to be noted that the sample fluctuation rotation speed calculating section may be constituted as high-pass filter means having a cutoff frequency of about 1 [Hz], for example, and the sample rotation speed v may be supplied to the high-pass filter means. Δv can be obtained. When the cutoff frequency is 1
The offset value can also be obtained by supplying the sample rotation speed v to a low-pass filter means of about [Hz].

At S61, the old error value E which has been stored in the memory for one rotation and whose storage address matches the current variable rotation speed group Δv is read out.
That is, the old error value group E obtained just one rotation before the rotor is read. Further, the average value of the old error value group E this time is calculated as the average old error value E _MEAN . Furthermore, the current sample variation speed Δv adjustment gain | 1-g / 2 | and the product of the average old error value E _MEAN
The sum of the product of the gain and the gain g is calculated as the output y. That is, the “output value calculation unit” is configured by the part of the computer 20 that executes S61.

In step S62, the offset value is added to the output y, whereby the current final rotational speed v, that is, the rotational speed v from which the periodic disturbance has been removed, is obtained.
Is required. That is, the “final rotation speed calculation unit” is configured by the part of the computer 20 that executes S62.

In S62, the signal delay and
The periodic disturbance removal state by the superimposition process is determined. Specifically, it is determined whether or not the final rotation speed v is substantially stable in time, and when it is stabilized, it is determined that the removal of the periodic disturbance is substantially completed. . Further, when it is determined that the removal of the periodic disturbance is substantially completed, it indicates that the removal of the periodic disturbance is substantially completed in the ON state, and it is determined that the removal of the periodic disturbance is not substantially completed in the OFF state. When the periodic disturbance removal completion flag (provided in the RAM 44) is turned on, and it is determined that the removal of the periodic disturbance has not been substantially completed, the periodic disturbance removal completion flag is set. It is also turned off. Here, “determination of whether or not the final rotation speed v is substantially stable in time” is performed, for example, every time the rotor 10 makes one rotation, the final rotation speed corresponding to each tooth 16 of the rotor 10 The sum of the absolute values of the values obtained by subtracting the current value from the previous value of v is obtained as the variation δ of the rotation speed v. If the variation δ is equal to or less than the reference value δ ₀ , the final rotation speed v is It can be determined that the time is almost stable.

In S63, the current output y is subtracted from the average old error value E _MEAN to obtain the current new error value E. That is, the “error value calculation unit” is configured by the part of the computer 20 that executes S63.

In S64, all the values of the old error value group E at this time are rewritten to the new error value E in the memory for one rotation. That is, this S in the computer 20
64 performs "one rotation memory update unit"
Is configured. Then, the process returns to S52.

The rotation speed calculation / correction technique has been described in detail above. One example of the effect of implementing this technique is shown in FIG.
3 shows a graph. In this graph, the frequency characteristic of the rotational speed v after the implementation of this technique is shown by a solid line, and for comparison with this, the frequency characteristic of the rotational speed v before the implementation of this technique, that is, FIG. The same thing as a graph is shown by the broken line. As is apparent from these graphs, the implementation of this technique effectively removes the periodic disturbance inherent in the wheels 14.

Next, the disturbance observer 52 will be described. The disturbance observer 52 is configured based on the model of the wheel 14 shown in FIG. Hereinafter, the configuration of the disturbance observer 52 will be described. The wheels 14, when modeled as being connected by a torsion spring 32 of the belt side 30 Togabane constant K of inertia J _R of the rim 28 and moment of inertia _{J B, (2) ~ (} 4) Is established, which constitutes a linear system. _{J R ω R '= -Kθ RB} + T 1 ··· (2) J B ω B' = Kθ RB -T d ··· (3) θ RB '= ω R -ω B ··· (4) provided that , Ω _R : angular velocity of rim side 28 ω _R ': angular acceleration of rim side 28 ω _B : angular velocity of belt side 30 ω _B ': angular acceleration of belt side 30 θ _RB : rim side 28 and belt Torsion angle with side 30 T ₁ : Driving / braking torque detected by driving / braking torque detecting device 68 T _d : Disturbance torque from road surface

Although a damper actually exists between the rim side portion 28 and the belt side portion 30, its influence is relatively small, and therefore its existence is neglected in this embodiment.

If the above state equation is expressed using a vector and a matrix, the following equation (5) is obtained.

[0091]

(Equation 9)

Here, the air pressure of the tire 26 changes, and the spring constant of the torsion spring 32 changes from K, which is a normal value, to K + ΔK.
The movement of the wheel 14 when the state changes to is expressed by equation (6).

[0093]

(Equation 10)

That is, the change of the spring constant K by ΔK is equivalent to the addition of a disturbance represented by the last term on the right side of the equation (6) to the normal tire 26. Since this disturbance includes information on the change amount ΔK of the spring constant K, and the spring constant K changes according to the air pressure of the tire 26,
By estimating the disturbance, the amount of change in the tire air pressure can be estimated. The disturbance observer is used for the estimation of the disturbance. If the torque _Td from the road surface is also treated as a disturbance, the disturbance w to be estimated is expressed by the following equation (7).

[0095]

[Equation 11]

However, theoretically, only one element of the disturbance [w] can be estimated, so that the second element w ₂ is estimated. By defining the disturbance w ₂ in (8), for the state equation of the wheel 14 is made to equation (9), constitutes a disturbance observer based on the equation (9). w ₂ = (− 1 / J _B ) T _d + (ΔK / J _B ) θ _RB (8)

[0097]

(Equation 12)

The disturbance observer estimates disturbance as one of the state variables of the system. Therefore, (8) for inclusion in the state of the disturbance w ₂ system equation to approximate the disturbance dynamics to be estimated by equation (10). w ₂ ′ = 0 (10) This means that the continuously changing disturbance is approximated stepwise (zero order approximation) as shown in FIG. 14, and the disturbance estimation speed of the disturbance observer 52 is estimated. This approximation is well tolerated if it is fast enough compared to the change in disturbance to be made. (10) from the equation, the inclusion of the disturbance w ₂ to the state of the system (11) extension system is constructed.

[0099]

(Equation 13)

In equation (11), [ω _B θ _RB w ₂ ] ^T cannot be detected. Therefore, if the disturbance observer 52 is configured based on this system,
The disturbance w ₂ and the state variables ω _B and θ _RB that cannot be measured originally can be estimated. In order to simplify the description, the vectors and matrices in equation (11) are decomposed and expressed as follows.

[0101]

[Equation 14]

At this time, the state [z] = [ω _B θ _RB w
₂ ] The configuration of the minimum dimension observer for estimating ^T is expressed by equation (12). [Z _p ′] = [A ₂₁ ] [x _a ] + [A ₂₂ ] [z _p ] + [B ₂ ] [u] + [G] ｛[x _a ′] − ([A ₁₁ ] [x _a ] + [A ₁₂ ] [z _p ] + [B ₁ ] [u])｝ = ([A ₂₁ ] − [G] [A ₁₁ ]) [x _a ] + ([A ₂₂ ] − [G] [ _{A 12]) [z p]} + [G] [x a '] + ([B 2] - [G] [B 1]) [u] ··· (12) However, [z _p]: [z ] [Z _p ']: change rate of the estimated value [z _p ] [G]: gain that determines the estimated speed of the disturbance observer 52 This equation is represented in a block diagram as shown in FIG. In the figure, [I] is a unit matrix, and s is a Laplace operator. If the error [e] between the true value [z] and the estimated value [z _p ] is [e] = [z] − [z _p ], and the rate of change of the error [e] is [e ′]. , (13) are obtained. [E '] = ([A 22] - [G] [A 12]) [e] ··· (13) which represents the estimated property of the disturbance observer 52, the matrix ([A _22] - [G [A ₁₂ ]) is the pole of the disturbance observer 52. Therefore, the estimated speed of the disturbance observer 52 increases as the eigenvalue moves away from the origin on the left half surface of the s-plane. The observer gain [G] may be determined so as to achieve a desired estimated speed.

A correlation operation is performed in the correlation operation section 54 using the disturbance estimation value w _2p and the torsion angle estimation value θ _RBp , and normalization is performed in the normalization section 56.
Of the spring constant K is determined.

First, in the correlation calculating section 54, a correlation calculation routine for acquiring a change in spring constant shown in the flowchart of FIG. 16 is executed. In the initial setting of S21, the integer i is reset to 1, and the disturbance w represented by the above equation (8) is obtained.
₂ between the estimated value w _2p and the estimated torsion angle θ _RBp C
Autocorrelation C between (w _2p , θ _RBp ) and estimated torsion angle θ _RBp
(Θ _RBp , θ _RBp ) are reset to 0. RAM5
The contents of the zero cross-correlation memory and the auto-correlation memory are set to zero.

Subsequently, in S22, the current estimated disturbance value w
_{2p (i)} and the estimated torsion angle θ _{RBp (i)} are read and S
At 23, the product of the disturbance estimation value w _{2p (i)} and the torsion angle estimation value θ _{RBp (i)} is calculated and added to the cross-correlation C (w _2p , θ _RBp ). However, when S23 is first executed, the cross-correlation C (w _2p , θ _RBp ) is 0, and therefore, the estimated disturbance w _{2p (i)} and the estimated torsion angle θ _{RBp (i) are} stored in the cross-correlation memory. Is merely stored. Similarly, the square of the estimated torsion angle θ _{RBp (i)} is calculated in _S24 and added to the autocorrelation C (θ _RBp , θ _RBp ) in the autocorrelation memory.

At S25, it is determined whether or not the integer i has become equal to or greater than the predetermined integer M. Since the determination is initially NO, the integer i is incremented by 1 at S26, and S22 to S24 are repeated. Be executed. When this execution is repeated M times, the determination in S25 becomes YES, and one execution of the correlation calculation routine for acquiring a spring constant change ends.

In the correlation calculation section 54, the cross-correlation C (w _2p , θ _RBp ) and the auto-correlation C (θ _RBp , θ
_RBp ), the L _K value is calculated by the normalization unit 56 according to the equation (21) and stored in the L _K value memory of the RAM 50. L _k = C (w _2p , θ _RBp ) / C (θ _RBp , θ _RBp ) (21) This L _K value is expressed by equation (22) based on equation (8). L _k = (− 1 / J _B ) C ₀ + ΔK / J _B (22) where C ₀ is C (T _dp , θ _RBp ) / C (θ _RBp , θ
_RBp ), which is independent of the change in the spring constant K, and can be compensated for by _obtaining the tire pressure in a normal state in advance. Also, C (T
_dp , θ _RBp ) is the estimated value of the disturbance torque T _d and the torsion angle θ _RB
Represents the cross-correlation with the estimated value.

In the spring constant change rate estimating section 58, L _K = C (w _2p , θ _RBp ) / C (θ _RBp , θ _RBp ) obtained as described above and stored in each L value memory. Is used to estimate the spring constant change amount ΔK of the torsion spring 32. As described above, since L _K is represented by L _K = (− 1 / J _B ) C ₀ + ΔK / J _B , the relationship between L _K and ΔK is stored in advance in the ROM 49 as a spring constant change table. The spring constant change amount ΔK is estimated based on this table. Further, the spring constant change rate γ is obtained by dividing the spring constant change amount ΔK by the normal value K.

In the estimated value correcting section 60, the estimated value γ is corrected so that the influence of the periodic disturbance mixed in the detected value of the rotational speed v is removed from the estimated value of the spring constant change rate γ. As described above, the periodic disturbance mixed in the detected value of the rotational speed v itself can be removed by the signal superimposition process by the rim side rotational speed calculation / correction unit 45, but the periodic disturbance is substantially completely eliminated. It takes time to be removed,
In the meantime, the influence of the periodic disturbance remaining on the detected value of the rotational speed v appears in the estimated value γ. On the other hand, tire 2
In a state in which the periodic disturbance caused by the non-uniformity of No. 6 is mixed with the rotational speed v and is not removed from the rotational speed v, the spring constant changes in a high-speed running state in which the vehicle body speed V is large even if the road surface roughness R is the same. The estimated value of the rate γ tends to be smaller than the true value, and the estimated value of the spring constant change rate γ becomes smaller than the true value in a flat road running state where the road surface unevenness R is low even when the vehicle speed V is the same. Tend. When the vehicle speed V is high or the road surface unevenness R is low, the ratio of the error value due to the periodic disturbance due to the unevenness of the tire 26 to the estimated value γ increases, and the influence of the periodic disturbance is strong to the estimated value γ. Because it will appear. Therefore, the estimated value correction unit 60 controls the vehicle speed until the periodic disturbance is sufficiently removed by the signal delay / superposition process, that is, until the periodic disturbance removal completion flag is turned on. The estimated value γ is corrected based on V and the road surface unevenness R.

Specifically, the correction value Δ is added to the estimated value γ.
The correction of the estimated value γ is performed by
The correction value Δ is conceptually represented by a graph in FIG.
As shown in FIG._S(For example, 10
0 (km / h)) at high speeds greater than α (eg
0.1), reference value V_SThe following low-speed driving conditions
Is determined to be 0, and the α is determined as shown in FIG.
As shown in the figure, the road surface roughness R is equal to the reference value R._SLess than
Α on a flat road₁, Reference value R _SHigher
Α when driving on uneven roads_Two(<Α₁)
It is determined.

The function of the estimated value correcting section 60 is fulfilled by the computer 47 executing the estimated value correcting routine of FIG. First, in step S111, a periodic disturbance removal completion flag is read from the computer 20. Next, in S112, it is determined whether or not the periodic disturbance removal completion flag is in the ON state, that is, whether or not the removal of the periodic disturbance is completed. If it is not completed this time, the determination is NO and S1
Go to step 13 and below.

In S113, vehicle speed sensor 70
From the vehicle speed V is read, then, in S114, whether the vehicle speed V is greater than the reference value V _S, that is, whether the vehicle is in a high-speed running state is determined. This time, if it is assumed that the vehicle is traveling at high speed, the determination is YE
In S115, the road surface unevenness degree R is read from the road surface unevenness sensor 72 in S115. Subsequently, in S116, the correction value Δ is determined. The correction value Δ is alpha ₁ of this time when the road asperity R is less than the reference value R _S, is higher than the reference value R _S is being determined in alpha _2. Then, in S117, the latest estimated value of the spring constant change rate γ is read from the RAM 50, and in S118,
The estimated value γ is corrected by adding the determined correction value Δ to the estimated value γ. The corrected estimated value γ is R
Returned to AM50. Then, the process returns to S111.

On the other hand, if the vehicle speed V is equal to or lower than the reference value V _S and the vehicle is running at a low speed, S114
Is NO, the steps after S115 are skipped, and the correction of the estimated value γ is omitted. This is because, when the vehicle is in the low-speed running state, the accuracy of the estimated value γ does not decrease so much, and the benefit of performing the correction is poor.

If the periodic disturbance elimination flag is in the ON state and the elimination of the periodic disturbance is completed, the process goes to S11.
The determination of 2 is YES, and the steps of S113 and subsequent steps are skipped, so that the correction of the estimated value γ is prohibited. Correcting the estimated value γ after the removal of the periodic disturbance means performing unnecessary correction on the estimated value γ that does not need to be corrected because the influence of the periodic disturbance no longer appears. On the contrary, the accuracy of the estimated value γ decreases.

[0115] In the abnormality determining unit 62, when the absolute value of the estimated values supplied from the estimated value correction section 60 gamma is determined whether or not the reference value gamma ₀ or is the reference value gamma ₀ or more tire pressure 26 is determined to be abnormal, when the reference value gamma ₀ is smaller than it is determined that the air pressure is normal. If it is determined that the air pressure is abnormal, the driver is notified by the display device 66 to that effect.

As is apparent from the above description, in the present embodiment, the electromagnetic pickup 12, the waveform shaper 18, and the computer 20 of S55 and S56 of FIG.
Performs the function of the disturbance observer 52, the correlation calculation unit 54, the normalization unit 56, and the spring constant change rate estimation unit 58 of the computer 47. The part that fulfills constitutes the “estimating means” in the invention of each claim, and the part of the computer 47 that fulfills the function of the estimated value correction unit 60 cooperates with the vehicle body speed sensor 70 and the road surface unevenness sensor 72 to It constitutes "estimated value correcting means" in the claimed invention. Further, in the computer 20, S5 in FIG.
The part executing steps 9 to S64 constitutes "detection value correcting means" in the invention of each claim . further,
A part of the computer 47 that executes S112 of FIG.
In the invention of claim 3, "Estimated value correction permission / prohibition
It constitutes "means".

In this embodiment, the estimated value of the spring constant change rate γ is corrected only when the vehicle speed V is greater than the reference value V _S , and the correction value is obtained when the road surface roughness R is equal to or less than the reference value R _S. Depending on whether or not there is, there are two stages, α ₁ and α _2. However, as shown in FIGS. 21 (a) and 21 (b), as the vehicle speed V increases, the road surface roughness R increases. It is also possible that the smaller the value, the larger the correction value Δ is determined. For example, the provisional correction value determined according to the vehicle speed V is multiplied by a correction coefficient that varies according to the road surface roughness R to obtain a final correction value, or the ROM 49 stores the vehicle speed V and the road surface roughness R respectively. A table is provided which is divided into a plurality of areas and one correction value is assigned for each combination of these areas, and the correction value Δ at each time is determined based on this table. In the former case, the correction value Δ changes continuously, and in the latter case, it changes stepwise. In any of these cases, it is possible to provide a region where correction is performed and a region where correction is not performed in at least one of the vehicle body speed V and the road surface roughness R, and a plurality of regions (or equivalent regions). It is also possible that the correction value Δ is determined to be the same value for a wide area). Further, the correction value can be changed stepwise for one of the vehicle speed V and the road surface unevenness R, and continuously for the other. Although not specifically exemplified, the invention of each claim can be embodied with various improvements and modifications.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a wheel information estimation device according to an embodiment of the present invention.

FIG. 2 is a configuration block diagram of the wheel information estimation device.

FIG. 3 is a sectional view showing a part of a wheel whose disturbance is detected by the wheel information estimating device.

FIG. 4 is a diagram showing a dynamic model of the wheel.

FIG. 5 is a flowchart showing a control program stored in a ROM of a computer which is a component of the wheel information estimation device.

FIG. 6 is a graph showing an example of a frequency characteristic of a wheel rotation speed signal.

FIG. 7 is a functional block diagram of a periodic disturbance remover (signal delay / superposition processor) in the wheel information estimating device.

FIG. 8 is a graph showing an example of a characteristic of the periodic disturbance removing unit.

FIG. 9 is a diagram conceptually showing a configuration of a memory for one rotation, which is a component of the wheel information estimation device, and a method of using the same.

FIG. 10 is a diagram for explaining the relationship between the contents stored in the memory for one rotation and the sampling period.

FIG. 11 is another diagram for explaining the relationship between the contents stored in the one-rotation memory and the sampling period.

FIG. 12 is a graph conceptually showing the principle of the periodic disturbance removing unit.

FIG. 13 is a graph showing an example of the effect of the periodic disturbance removing unit.

FIG. 14 is a graph for explaining approximation of disturbance dynamics in the wheel information estimation device.

FIG. 15 is a block diagram showing a disturbance observer in the wheel information estimation device.

FIG. 16 is a flowchart showing a control program stored in a ROM of a computer which is a component of the wheel information estimating apparatus.

FIG. 17 is a graph conceptually showing an example of correction of an estimated value in the wheel information estimating device.

FIG. 18 is a flowchart showing a control program stored in a ROM of a computer which is a component of the wheel information estimation device.

FIG. 19 is a block diagram conceptually showing the configuration of each of the first and second aspects of the present invention.

FIG. 20 is a block diagram conceptually showing a configuration of the invention of claim 3;

FIG. 21 is a graph conceptually showing another example of the correction of the estimated value in the wheel information estimating device.

[Explanation of symbols]

 Reference Signs List 10 rotor 12 electromagnetic pickup 14 wheels (wheels with tires) 20 computer 26 tires 47 computer 52 disturbance observer 58 spring constant change rate estimating unit 60 estimated value correcting unit 70 vehicle speed sensor 72 road surface unevenness sensor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Kawai 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hiroyoshi Kojima 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 72) Inventor Koji Umeno 41 Toyota Chuo R & D Laboratories Co., Ltd. at 41, Chuchu-ji, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture (72) Inventor Katsuhiro Asano 41 Co., Ltd. Inside the Central Research Laboratory (72) Inventor Shunji Naito 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Inside Denso Co., Ltd. (72) Inventor Nobuyoshi Onoki 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Corporation (56 ) References JP-A-5-294119 (JP, A) JP-A-5-213018 (JP, A) JP-A-5-133831 (JP, A) JP-A-7-172121 (JP, A) JP-A-6-320923 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60C 23/00-23/08 G01L 17 / 00 B60T 8/00-8/96

Claims (3)

(57) [Claims] 1. A wheel information estimating device comprising: a detecting device for detecting a rotational speed of a wheel; and estimating means for estimating information on the wheel based on a detected value by the detecting device. , Periodic out mixed with it
Correction is made so that disturbance is removed and supplied to the estimating means.
A detection value correction unit configured to detect the value estimated by the estimation unit without being removed by the detection value correction unit based on a traveling state of the vehicle;
Estimated value of the effect of periodic disturbance remaining in the value detected by the device
Wheel information estimating apparatus is characterized by providing an estimated value correction means for correcting so as not to appear in. 2. The wheel information estimating device according to claim 1, wherein the estimated value correcting means determines whether or not the amount of correction of the estimated value by the estimating means is small when the vehicle speed as the traveling condition is large. A wheel information estimating device that performs at least one of determining a larger value and determining a larger value when the road surface unevenness degree as the traveling condition is low and high. 3. The wheel information estimating device according to claim 1, further comprising:
The estimated value correction permitting / prohibiting means for permitting the correction by the estimated value correcting means while the periodic disturbance remaining in the detected value by the detecting device is larger than the permissible value, and prohibiting the correction after the value becomes equal to or less than the permissible value. Including wheel information estimation device.