JP2021088349A - Wheel diameter correction device, correction system and program - Google Patents

Abstract

To accurately correct a wheel diameter of a vehicle by a general-purpose method.SOLUTION: A wheel diameter correction device uses data including right and left wheel angular speeds which are acquired by right and left wheel speed sensors of a vehicle and a vehicle body angular speed at vehicle turning which is acquired by a yaw rate sensor fitted to the vehicle to estimate a wheel diameter of the vehicle on the basis of a simultaneous equation relating to the wheel angular speeds, the vehicle body angular speed and a wheel diameter.SELECTED DRAWING: Figure 3

Description

The present invention relates to a wheel diameter correction device, a correction system, and a program.

In vehicle control, a technique for correcting the wheel diameter and accurately obtaining the vehicle speed is required.

For example, there is a technique for correcting the wheel diameter without depending on the difference between the left and right wheel speeds for straight running and steady turning running (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-213761

In the conventional technique, the actual speed ratio is calculated, and the turning radius is obtained from this value with reference to the speed ratio map prepared in advance and averaged. The speed ratio between the left and right front wheels and the left and right rear wheels is obtained from the average turning radius, and the correction coefficient for each tire is obtained from the speed ratio.

However, when obtaining the turning radius from the actual speed ratio, it is necessary to create a speed ratio map for obtaining the turning radius corresponding to the speed ratio in advance. There is a restriction that the speed ratio map needs to be prepared for each vehicle having various structures such as size. Therefore, there is a problem that it is difficult to utilize it for general-purpose vehicle control.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wheel diameter correction device, a correction system, and a program capable of accurately correcting the wheel diameter of a vehicle by a general-purpose method.

In order to achieve the above object, the wheel diameter correction device according to the present invention has the left and right wheel angle speeds obtained by the left and right wheel speed sensors of the vehicle and the yaw rate sensor attached to the vehicle when the vehicle is turning. It is configured to include a wheel diameter calculation unit that estimates the wheel diameter of the vehicle based on the simultaneous equations relating to the wheel angle speed, the vehicle body angle speed, and the wheel diameter using the data of the vehicle body angle speed in the above. ..

The program according to the present invention uses the data of the left and right wheel angular speeds obtained by the left and right wheel speed sensors of the vehicle and the vehicle body angular speeds when the vehicle is turning, which are obtained by the yaw rate sensor attached to the vehicle. The program is characterized in that a computer is made to execute a process including estimating the wheel diameter of the vehicle based on a simultaneous equation regarding the wheel angle speed, the vehicle body angle speed, and the wheel diameter.

According to the wheel diameter correction device, the correction system, and the program of the present invention, the wheel diameter of the vehicle can be corrected with high accuracy by a general-purpose method.

It is a figure which shows the relationship of each value at the time of turning of the oncoming motorcycle running. It is a figure which shows the relationship of each value at the time of turning of four-wheel running at a low speed. It is a block diagram which shows the structure of the correction system of 1st Embodiment. It is a block diagram which shows the processing structure of a wheel diameter correction device. It is a block diagram which shows the hardware structure of the wheel diameter correction device. It is a sequence which shows the flow of the correction process by the correction system of 1st Embodiment. It is a block diagram which shows the structure of the correction system of 2nd Embodiment. It is a sequence which shows the flow of the correction process by the correction system of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Before explaining the configuration of each embodiment of the present invention (hereinafter, the points common to each embodiment are referred to as the present embodiment), first, the outline and the principle of the method of the present embodiment will be described.

The outline of this embodiment will be described. In this embodiment, it is necessary to obtain the wheel speed by using the values of the left and right wheel speed sensors and the yaw rate sensor during running (mainly turning) without using the speed ratio map that needs to be prepared in advance. It is possible to estimate the wheel diameter online. In the following, when both the wheel speed sensor and the yaw rate sensor are represented, they are simply referred to as sensors.

The yaw rate (hereinafter, also referred to as vehicle body angular velocity) is obtained from the difference between the left and right wheel speeds and the distance between the wheels (hereinafter, also referred to as tread) when the vehicle body turns. It can also be obtained from a sensor attached to the vehicle. The wheel speed can be obtained from the wheel angular velocity and the wheel diameter. The wheel angular velocity can be obtained from the wheel speed sensors of each of the left and right wheels. By summarizing these relationships, a relational expression can be obtained with six variables: yaw rate, left and right wheel angular velocities, left and right wheel diameters, and tread. The relational expression will be described later.

In the relational expression, the known value and the unknown value are defined as follows. The yaw rate and the left and right wheel angular velocities are known values by the sensor attached to the vehicle. In addition, the tread becomes a known value depending on the catalog value of the vehicle. Therefore, the relational expression is such that the two left and right wheel diameters have unknown values. From this, the left and right wheel diameters can be estimated by measuring at least two times when the output values of the yaw rate sensor and the wheel speed sensor are different.

The above is the outline of the present embodiment. Next, the principle of the above-mentioned relational expression will be described.

・・・（１） FIG. 1 is a diagram showing the relationship between each value when the two-wheeled vehicle travels on the opposite side during turning. FIG. 2 is a diagram showing the relationship between each value when the four-wheeled vehicle travels at a low speed and turns. When turning with the oncoming two-wheel model (Fig. 1) and the four-wheel model at low speed (Fig. 2), the left and right wheel speeds V _r and V _l are different. The four-wheel model has different rear wheel speeds. Yaw rate ω _c is generated when turning. Assuming that the tread is W, the equation for obtaining the yaw rate is as shown in Eq. (1).

... (1)

・・・（２） Further, the left and right wheel speeds _{can be expressed as equation (2) when the respective wheel angular velocities are ω r} and ω _l and the wheel diameters are d + Δd and d−Δd.

... (2)

・・・（３−１）
式（３−１）について、Ａ＝ω_ｒ−ω_ｌ、Ｂ＝ω_ｒ＋ω_ｌとおくと式（３−２）となる。

・・・（３−２） _{Assuming that ω c} , ω _r, and ω _l are known information by the yaw rate sensor and the wheel speed sensor, the following equations (3-1) and (3) are used using the equations (1) and (2). The relationship of -2) can be obtained.

... (3-1)
For equation (3-1), if A = ω _r −ω _l and B = ω _r + ω _l , then equation (3-2) is obtained.

... (3-2)

・・・（４） From equation (3-2), by performing two turns with different yaw rates, the simultaneous equations shown in equation (4) are obtained.

... (4)

・・・（５） By solving the simultaneous equations of the equation (4), the left and right wheel diameters shown in the equation (5) can be obtained.

... (5)

The above is the explanation of the principle of the relational expression. Based on the above principle, the configuration and operation of the embodiment will be described below.
<Structure and operation of the first embodiment>
FIG. 3 is a block diagram showing the configuration of the correction system of the first embodiment. The correction system 100 of FIG. 3 is assumed to be mounted on a vehicle, and has a configuration in which a sensor, an ECU (Electronic Control Unit), and the like are integrated, and a wheel diameter correction device is mounted so as to cooperate with these. The correction system 100 includes a wheel speed sensor 102, a yaw rate sensor 104, a turning determination unit 106, a wheel diameter storage unit 108, a wheel diameter correction device 110, and an ECU 120. The ECU 120 is an example of a control device. The ECU 120 includes a calculation unit 122 and a drive control unit 124.

FIG. 4 is a block diagram showing a processing configuration of the wheel diameter correction device 110. As shown in FIG. 4, the wheel diameter correction device 110 includes an input unit 112, a wheel diameter calculation unit 114, and an output unit 116.

FIG. 5 is a block diagram showing a hardware configuration of the wheel diameter correction device 110.

As shown in FIG. 5, the wheel diameter correction device 110 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a storage 14, an input unit 15, a display unit 16, and communication. It has an interface (I / F) 17. The configurations are connected to each other via a bus 19 so as to be communicable with each other.

The CPU 11 is a central arithmetic processing unit that executes various programs and controls each part. That is, the CPU 11 reads the program from the ROM 12 or the storage 14, and executes the program using the RAM 13 as a work area. The CPU 11 controls each of the above configurations and performs various arithmetic processes according to the program stored in the ROM 12 or the storage 14. In the present embodiment, the wheel diameter correction program is stored in the ROM 12 or the storage 14.

The ROM 12 stores various programs and various data. The RAM 13 temporarily stores a program or data as a work area. The storage 14 is composed of a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and stores various programs including an operating system and various data.

The input unit 15 includes a pointing device such as a mouse and a keyboard, and is used for performing various inputs.

The display unit 16 is, for example, a liquid crystal display and displays various types of information. The display unit 16 may adopt a touch panel method and function as an input unit 15.

The communication interface 17 is an interface for communicating with other devices such as terminals, and for example, standards such as Ethernet (registered trademark), FDDI, and Wi-Fi (registered trademark) are used. The turning determination unit 106 and the prevention determination unit 210, which will be described later in the second embodiment, may be realized by the same hardware configuration as the wheel diameter correction device 110 or a microcontroller.

Next, each functional configuration of the wheel diameter correction device 110 will be described. Each functional configuration is realized by the CPU 11 reading out the wheel diameter correction program stored in the ROM 12 or the storage 14, deploying it in the RAM 13, and executing it.

The input unit 112 receives data on the left and right wheel angular velocities obtained by the left and right wheel speed sensors 102 and the vehicle body angular velocity determined by the turning determination unit 106 among the vehicle body angular velocities obtained by the yaw rate sensor 104. The input unit 112 receives the data of the vehicle body angular velocity at the time of turning at least twice, and performs the following processing of the wheel diameter calculation unit 114.

The wheel diameter calculation unit 114 solves the simultaneous equations of the above equation (4) regarding the wheel angular velocity, the vehicle body angular velocity, and the wheel diameter, and estimates the wheel diameter of the vehicle from d and Δd shown in the equation (5). .. The wheel diameter calculation unit 114 uses the data for at least two times during turning, and for each of the data, the relationship between the sum and difference of the left and right wheel angular velocities obtained from the wheel speed sensor and the vehicle body angular velocity during turning. _{The calculation result 2 Wω c} obtained by calculating the equation (the above equation (3-1)) is obtained. Then, the wheel diameter calculation unit 114 solves the simultaneous equations (the above equation (4)) as shown in the equation (5) by using the difference between the calculation results of the data acquired twice, and the left and right wheels of the vehicle. Estimate the diameter. As described in the above principle, the right and left wheel diameters are obtained as d + Δd and d−Δd, respectively.

The output unit 116 stores the estimated left and right wheel diameters of the vehicle in the wheel diameter storage unit 108. The above processing by the wheel diameter correction device 110 may be repeated.

Next, other processing of the correction system will be described.

The calculation unit 122 of the ECU 120 corrects the vehicle speed of the vehicle based on the wheel diameter of the vehicle stored in the wheel diameter storage unit 108 and the left and right wheel angular velocities. When the wheel diameter correction process by the wheel diameter correction device 110 is performed a plurality of times and the wheel diameter estimated a plurality of times is obtained, the estimated average wheel diameter is used. The vehicle speed is obtained by vehicle speed = wheel angular velocity x wheel diameter. The ECU 120 performs drive control by the drive control unit 124 according to the corrected vehicle speed.

The turning determination unit 106 estimates the yaw rate threshold value from the wheel diameter of the vehicle stored in the wheel diameter storage unit 108, makes a turning determination at the time of turning using the yaw rate threshold value, and transmits the result of the turning determination to the wheel diameter correction device 110. Output. In the estimation of the yaw rate threshold value, the wheel diameter of the vehicle is applied by the above equation (2), and V _r and V _l of the above equation (1) can be calculated. The yaw rate threshold value may be set so as to be determined based on the value of the _{yaw rate ω c} obtained by the equation (1) obtained by this. When the process by the wheel diameter correction device 110 is repeated, the yaw rate threshold value may be set to be corrected by using a moving average of the values of the _{yaw rate ω c or the like.} In the initial state, the yaw rate threshold value may be set to an initial value.

Next, the operation of the correction system 100 according to the first embodiment of the present invention will be described. The following will be described by taking the case of four-wheel driving as an example.

FIG. 6 is a sequence showing the flow of correction processing by the correction system 100 of the first embodiment. In the wheel diameter correction device 110, the wheel diameter correction process is performed by the CPU 11 reading the wheel diameter correction program from the ROM 12 or the storage 14, deploying the program in the RAM 13 and executing the program. The correction process of this sequence by the correction system 100 is repeated.

In step S100, the wheel speed sensor 102 acquires the left and right wheel angular velocities of the vehicle, and the yaw rate sensor 104 acquires the vehicle body angular velocity. The wheel angular velocity is output to the turning determination unit 106, the wheel diameter correction device 110, and the ECU 120. The vehicle body angular velocity is output to the turning determination unit 106. The process is repeated.

In step S102, the turning determination unit 106 determines whether or not the vehicle is turning at a low speed. When the conditions are satisfied, that is, when it is determined that the vehicle is turning at a low speed, the vehicle body angular velocity at the time of turning is output to the wheel diameter correction device 110. If the conditions are not met, the process is repeated without outputting anything. The process of this step is repeated every time the vehicle body angular velocity is accepted. To determine the low speed, the low speed threshold value of the vehicle may be set in advance with respect to the wheel angular velocity or the vehicle body angular velocity. The determination during turning may be made based on whether or not the degree of change in the vehicle body angular velocity acquired in step S100 is equal to or greater than the yaw rate threshold value. In addition, it may be managed by a flag when turning or not turning. Further, in this case, since it is a case of four-wheel driving, a low speed is set as a condition, but in a case of two-wheel running, the low speed may not be included in the condition. The low speed may be determined by the wheel diameter correction device 110.

In step S104, the input unit 112 of the wheel diameter correction device 110 receives data of the left and right wheel angular velocities obtained by the left and right wheel speed sensors 102 and the vehicle body angular velocity determined to be during turning by the turning determination unit 106.

In step S106, the wheel diameter calculation unit 114 calculated the relational expression regarding the sum and difference of the left and right wheel angular velocities obtained from the wheel speed sensor 102 and the vehicle body angular velocity during turning with respect to the data received in step S104. To get.

In step S108, it is determined in step S106 whether or not the data for two or more times has been calculated. If the data has been calculated, the process proceeds to step S110. If not, the process returns to step S104 and repeats the process. ..

In step S110, the wheel diameter calculation unit 114 solves the simultaneous equations (the above equation (4)) as shown in the equation (5) using the difference between the calculation results of the data acquired twice, and the left and right of the vehicle. Estimate the wheel diameter of. The right and left wheel diameters are obtained as d + Δd and d−Δd, respectively.

In step S112, the output unit 116 stores the estimated left and right wheel diameters of the vehicle in the wheel diameter storage unit 108.

In step S114, the calculation unit 122 of the ECU 120 corrects the vehicle speed of the vehicle based on the average wheel diameter estimated by the wheel diameter correction device 110 and the left and right wheel angular velocities.

In step S116, the turning determination unit 106 estimates the yaw rate threshold value from the wheel diameter of the vehicle stored in the wheel diameter storage unit 108. When this sequence is repeated, the yaw rate threshold value estimated in this step is reflected in the yaw rate threshold value of the process in step S102. The above processing of this sequence is repeated as appropriate to correct the wheel diameter. This is because the wheel diameter changes due to deformation, wear, and the like.

As described above, according to the correction system according to the first embodiment of the present invention, the wheel diameter of the vehicle can be corrected with high accuracy by a general-purpose method.

<Structure and operation of the second embodiment>
Next, the second embodiment will be described. In the second embodiment, assuming a case where slip occurs in a bad environment or the like, when slip occurs, the wheel diameter is estimated using an erroneous estimation result, and the prevention determination is made so as not to correct the vehicle speed. Do.

Here, the problem of prevention determination in the prior art will be described. In the prior art, there is a method of determining slip by obtaining the average wheel speed of the front wheels (left and right) and the average wheel speed of the rear wheels (left and right), respectively, and comparing the difference value with the threshold value. There is also a method of calculating the wheel acceleration (differential value of the wheel speed) from the wheel speed sensor of each wheel and determining slip when the acceleration exceeds a predetermined threshold value. However, there is a problem that it is difficult to determine slip detection under specific conditions. For example, when the slip is judged by the method using the average wheel speed, even if either the front and rear wheels on the left side or the front and rear wheels on the right side slip, only the calculated average value of the wheel speed can be referred to, so an appropriate judgment can be made. There is a problem that it cannot be done. In addition, when the slip is judged by the method using acceleration, the judgment can be made where the value of the road surface μ changes, but if the slipped state continues, the change in acceleration cannot be grasped, so that the judgment cannot be made. There is. Therefore, in the method using the average wheel speed, an appropriate prevention determination may not be possible depending on the conditions of the left and right wheels. In the method using acceleration, it may not be possible to make an appropriate prevention judgment depending on the situation, such as when slipping continues for a certain period of time and the acceleration becomes constant. As described above, there is a problem in the prevention determination using unique information such as the average wheel speed or the acceleration. On the other hand, in the method of the second embodiment of the present invention, since the prevention determination is performed by combining the information of the wheel speed sensor and the yaw rate sensor, there is an advantage that an appropriate prevention determination can be robustly performed even in the above-mentioned situations. ..

FIG. 7 is a configuration diagram of the correction system 200 of the second embodiment. As shown in FIG. 7, the sensor outputs of the wheel speed sensor 102 and the yaw rate sensor 104 are determined by providing the prevention determination unit 210, and then the process proceeds to the wheel diameter correction device 110. The wheel diameter correction device 110 stores the calculated wheel diameters d and Δd in the wheel diameter storage unit 108.

The prevention determination unit 210 indicates a predetermined driving condition based on the wheel diameter stored in the wheel diameter storage unit 108 in advance, the left and right wheel angular velocities obtained by the wheel speed sensor, and the vehicle body angular velocity obtained by the yaw rate sensor 104. Find the value α. The prevention determination unit 210 compares the determination threshold value β predetermined for the yaw rate sensor 104 with the predetermined value α to determine whether or not to estimate the wheel diameter.

・・・（６）
所定の値αの計算では、走行開始時、つまり補正ができていない状態の車輪径には、初期値ｄ＝定数（タイヤの直径）、Δｄ＝０を設定する。所定の値αを求めるための変数としては、車輪径に対応するｄ及びΔｄ、ヨーレートセンサ１０４のヨーレートω_ｃ、車輪速センサ１０２の車輪角速度ω_ｒ及びω_ｌ、並びにトレッドＷを用いる。車輪径に対応するｄ及びΔｄは、αの計算の際に最新の値を車輪径記憶部１０８から取得する。判定閾値βはヨーレートセンサ１０４の性能に応じて定めればよい。 The prevention determination unit 210 obtains a predetermined value α by the following equation (6), and determines whether or not the predetermined value α is larger than the determination threshold value β.

... (6)
In the calculation of the predetermined value α, the initial value d = constant (tire diameter) and Δd = 0 are set for the wheel diameter at the start of traveling, that is, in the state where the correction has not been performed. As variables for obtaining a predetermined value α, d and Δd corresponding to the wheel diameter, the yaw rate ω _c of the yaw rate sensor 104, the wheel angular velocities ω _r and ω _{l of} the wheel speed sensor 102, and the tread W are used. The latest values of d and Δd corresponding to the wheel diameters are acquired from the wheel diameter storage unit 108 when calculating α. The determination threshold value β may be determined according to the performance of the yaw rate sensor 104.

In the correction system 200, the left and right wheel angular velocities are monitored by the wheel speed sensor 102, and when a yaw rate is generated, the yaw rate can be calculated by the equation (1) by paying attention to the difference between these values. However, there is a possibility that the wheel diameter may be erroneously estimated in situations such as understeer or oversteer due to the influence of a bad environment such as tire slippage, or when an abnormal value is input from the yaw rate sensor 104. In the case where the above can occur, comparing the yaw rate (second term) obtained from the known wheel diameter and the left and right wheel angular velocities ω _r and ω _{l with the value ω c} (first term) obtained by the yaw rate sensor 104. , The difference is expected to be large. Therefore, the determination threshold value β is set to have a width according to the performance of the yaw rate sensor 104. A predetermined value α can be obtained according to the equation (6) from the wheel diameters d and Δd obtained in advance, the left and right wheel angular velocities ω _r and ω _l, and the value ω _{c of the yaw rate sensor.} By comparing the magnitude of the predetermined value α with the determination threshold value β, it can be determined whether or not the tire is slipping due to the influence of a bad environment such as slipping, and if it is determined that the tire is slipping, the turning is performed. By not estimating the wheel diameter in, it is possible to prevent erroneous wheel speed correction.

FIG. 8 is a sequence showing the flow of correction processing by the correction system 200 of the second embodiment. In the second embodiment, the prevention determination unit 210 determines the determination result before outputting the sensor data of the wheel speed sensor 102 and the yaw rate sensor 104 in step S100 to the turning determination unit 106 and the wheel diameter correction device 110. Controls whether or not to output accordingly. In this way, in the correction system 200, by controlling the sensor output by the prevention determination unit 210, it is possible to control whether the wheel diameter correction device 110 estimates the wheel diameter after preventing erroneous estimation. It should be noted that the output may be performed in the same manner as in the first embodiment, and it may be controlled whether or not the wheel diameter correction device 110 processes the signal according to the signal from the prevention determination unit 210.

In step S200, the prevention determination unit 210 calculates a predetermined value α according to the above equation (6). As variables for obtaining a predetermined value α, d and Δd corresponding to the wheel diameter, the yaw rate ω _c of the e-rate sensor 104, the wheel angular velocities ω _r and ω _{l of} the wheel speed sensor 102, and the tread W are used. The latest values of d and Δd corresponding to the wheel diameters are acquired from the wheel diameter storage unit 108 when calculating α.

In step S202, the prevention determination unit 210 determines whether or not a predetermined value α> determination threshold value β. If α> β, the process proceeds to step S204 assuming that no slip has occurred, and if α> β, the process proceeds to step S206 assuming that slip has occurred.

In step S204, the prevention determination unit 210 outputs sensor data (wheel angular velocity and vehicle body angular velocity) to the turning determination unit 106 and the wheel diameter correction device 110.

In step S206, the prevention determination unit 210 ends the process without outputting the sensor data.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the gist of the present invention.

For example, in the above-described first embodiment, the case where the difference between the calculation results of the data acquired twice has been used as an example has been described, but the present invention is not limited to this. For example, data is acquired three times or more, and the simultaneous equation is solved using the difference between the calculation result of the first data and the calculation result of arbitrary data after the third time, and the calculation result of the first and second data is used. The wheel diameter may be estimated in comparison with the case of the difference between the two. The data for which the difference is to be obtained may be arbitrary data. This is expected to reduce the estimation error.

100, 200 Correction system 102 Wheel speed sensor 104 Yaw rate sensor 106 Turning judgment unit 108 Wheel diameter storage unit 110 Wheel diameter correction device 112 Input unit 114 Wheel diameter calculation unit 116 Output unit 122 Calculation unit 124 Drive control unit 210 Prevention judgment unit

Claims (6)

The wheel angle speed and the vehicle body angle speed are used by using the data of the left and right wheel angle speeds obtained by the left and right wheel speed sensors of the vehicle and the vehicle body angle speed when the vehicle is turning, which is obtained by the yaw rate sensor attached to the vehicle. And the wheel diameter calculation unit that estimates the wheel diameter of the vehicle based on the simultaneous equations with respect to the wheel diameter.
Wheel diameter correction device including. The data at the time of the turning is acquired a plurality of times, and the data is acquired.
The wheel diameter calculation unit
For each of the above data, the calculation result of calculating the relational expression regarding the sum and difference of the left and right wheel angular velocities obtained from the wheel speed sensor and the vehicle body angular velocity was obtained.
The wheel diameter correction device according to claim 1, wherein the simultaneous equations are solved by using the difference between the calculation results of the data acquired a plurality of times to estimate the left and right wheel diameters of the vehicle. A correction system including the wheel diameter correction device according to claim 1 or 2, and a control device including a calculation unit.
The wheel diameter calculation unit of the wheel diameter correction device estimates the average wheel diameter of the left and right wheel diameters, and determines the average wheel diameter.
The calculation unit of the control device is a correction system that corrects the vehicle speed of the vehicle based on the estimated average wheel diameter and the left and right wheel angular velocities. Including the turning judgment unit
The correction system according to claim 3, wherein the turning determination unit estimates a yaw rate threshold value from the estimated wheel diameter of the vehicle, and makes a turning determination at the time of turning using the yaw rate threshold value. Including the prevention judgment part
The prevention determination unit indicates a predetermined operating state based on the left and right wheel diameters stored in advance, the left and right wheel angular velocities obtained by the wheel speed sensor, and the vehicle body angular velocity obtained by the yaw rate sensor. The correction system according to claim 3 or 4, wherein the value of the wheel diameter is obtained, and the determination threshold value determined in advance for the yaw rate sensor is compared with the predetermined value to determine whether or not to estimate the wheel diameter. .. Using the data of the left and right wheel angular velocities obtained by the left and right wheel speed sensors and the vehicle body angular velocity obtained by the yaw rate sensor attached to the vehicle when the vehicle is turning, the wheel angular velocity, the vehicle body angular velocity, and the wheels Estimate the wheel diameter of the vehicle based on the simultaneous equations with respect to the diameter.
A program characterized by having a computer execute a process including the above.

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