JP6396188B2 - Vehicle body speed estimation device - Google Patents

Description

  The present invention relates to a vehicle body speed estimation device, for example, a technique for estimating a vehicle body speed required when performing traction control and antilock brake control.

  In the traction control device and the antilock brake control device, the vehicle body speed is required when the slip ratio control is performed. In vehicles equipped with braking force generation means on all wheels, when estimating the vehicle speed from the wheel speed, all wheels may slip in the locking direction with respect to the road surface, and the drive wheels also slip in the spin direction. Therefore, it is necessary to determine the wheel with the smallest slip.

For example, the following conventional examples are known as conventional vehicle body speed calculation devices.
In this conventional example, the wheel speeds of all the wheels are individually detected by the wheel speed sensor, and when the antilock brake control is not commanded, the lowest value among the wheel speeds is estimated as the vehicle body speed, An antilock brake control device is disclosed in which when the antilock brake control is commanded, the highest value among the wheel speeds is estimated as the vehicle body speed (Patent Document 1).

Japanese Laid-Open Patent Publication No. 1-218953

In the conventional example, when all the wheels tend to be locked or spin, the vehicle body speed is estimated from the wheel speed of the most gripped wheel, and a vehicle body speed close to the actual vehicle body speed is obtained.
However, when driving torque is applied to one wheel or a plurality of wheels and braking torque is applied to another wheel or a plurality of other wheels, and a wheel having a tendency to lock and a wheel having a tendency to spin are mixed, the conventional example has the highest value or the lowest value. Since the value is estimated as the vehicle speed, the estimated vehicle speed may be far from the actual vehicle speed.

  An object of the present invention is a vehicle capable of accurately estimating the vehicle body speed from the wheel speed in a vehicle capable of generating a braking force on at least one other wheel when a driving force is generated on at least one wheel. A vehicle speed estimation device is provided.

The vehicle body speed estimation device 5 of the present invention includes a braking / driving force generating means 6 capable of generating a driving force and a braking force for all the wheels 1 to 4. From the wheel speeds of the wheels 1 to 4, A vehicle speed estimation device for estimating a vehicle speed,
A determination means 20 for determining whether or not the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than a threshold and whether the positive / negative values are mixed for the braking / driving forces of all the wheels 1 to 4;
When it is determined by the determination means 20 that the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than the threshold value, and the braking / driving forces of all the wheels 1 to 4 are mixed, the braking / driving force is determined. The wheel with the lowest wheel speed among the positive wheels and the wheel with the highest wheel speed among the wheels with the negative braking / driving force are extracted, and the wheel angular acceleration and the norm for the two extracted wheels i are extracted. Deviation calculating means 21 for calculating a deviation from the wheel angular acceleration;
Vehicle body speed estimation means 22 for estimating the vehicle body speed according to a standard determined from the wheel speed of the wheel i having the smaller absolute value among the deviations calculated by the deviation calculation means 21;
Is provided.
The “driving force and braking force” are collectively referred to as “braking / driving force”.
The threshold value and the determined standard are determined by results of tests, simulations, and the like.
The reference wheel angular acceleration is an ideal wheel angular acceleration when there is no slip calculated from the longitudinal acceleration generated in the vehicle body by the sum of braking / driving forces acting on each wheel.

  According to this configuration, the vehicle body speed estimation device 5 for this vehicle estimates the vehicle body speed from the wheel speeds of the wheels 1 to 4 as follows. The determination means 20 determines whether or not the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than the threshold value and whether the positive / negative values are mixed for the braking / driving forces of all the wheels 1 to 4. That is, the determination means 20 determines whether a wheel having a lock tendency and a wheel having a spin tendency are mixed for all the wheels 1 to 4.

The deviation calculating means 21 determines that the wheel speed is the lowest among the wheels with positive braking / driving force and the wheel with the highest wheel speed among the wheels with negative braking / driving force. And the deviation between the wheel angular acceleration and the reference wheel angular acceleration is calculated for the two extracted wheels i. This is because, from the two wheels i, a wheel i having a wheel angular acceleration approximating a reference wheel angular acceleration that is an ideal wheel angular acceleration when there is no slip, that is, a wheel i having the smallest slip is found. The vehicle body speed estimating means 22 estimates the vehicle body speed from the wheel speed of the wheel i having the smaller absolute value of the deviation.
Thus, even when all of the wheels 1 to 4 have large slips and a mixture of wheels with a tendency to lock and a tendency to spin, the vehicle body speed is estimated from the wheel speed of the wheel i with the smallest slip, so that it is more accurate than the conventional example. The vehicle speed can be estimated.

  The determination means 20 has a function of determining whether or not there is a wheel i having an absolute value of braking / driving force less than a threshold. The wheel i having an absolute value of braking / driving force less than the threshold is determined by the determination means 20. When it is determined that the vehicle speed exists, the vehicle body speed estimation means 22 may estimate the vehicle body speed according to a standard determined from the wheel speed of the wheel i less than the threshold. In this case, when the determination means 20 determines that there is a wheel i whose absolute value of the braking / driving force is less than the threshold, that is, there is a gripping wheel i, the vehicle body speed estimation means 22 performs the grip. The vehicle body speed is estimated from the wheel speed of the existing wheel i. Therefore, it is possible to prevent the estimated vehicle body speed from deviating from the actual vehicle body speed.

  The determination means 20 has a function of determining whether or not the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than a threshold value and whether the braking / driving forces of all the wheels 1 to 4 are negative. When the determination means 20 determines that the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than the threshold value and the braking / driving forces of all the wheels 1 to 4 are negative, The vehicle body speed estimation means 22 may estimate the vehicle body speed in accordance with a reference determined from the wheel speed of the wheel i having the highest wheel speed.

  When the absolute value of the braking / driving force of all the wheels 1 to 4 is equal to or greater than the threshold and the braking / driving force of all the wheels 1 to 4 is negative, that is, when all the wheels 1 to 4 are in a lock tendency. By selecting the wheel i having the highest wheel speed from these wheels 1 to 4, it is possible to find the wheel i that is most gripped. The vehicle body speed can be estimated from the wheel speed of the most gripping wheel i. Therefore, it is possible to prevent the estimated vehicle body speed from deviating from the actual vehicle body speed.

  The determination means 20 has a function of determining whether or not the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than a threshold value and the braking / driving forces of all the wheels 1 to 4 are positive. When the determination means 20 determines that the absolute values of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than the threshold value and the braking / driving forces of all the wheels 1 to 4 are positive, The vehicle body speed estimation means 22 may estimate the vehicle body speed according to a standard determined from the wheel speed of the wheel i having the lowest wheel speed.

  When the absolute value of the braking / driving force of all the wheels 1 to 4 is equal to or greater than the threshold value and the braking / driving force of all the wheels 1 to 4 is positive, that is, all the wheels 1 to 4 are in a spin tendency. By selecting the wheel i having the lowest wheel speed from these wheels 1 to 4, it is possible to find the wheel i that is most gripped. The vehicle body speed can be estimated from the wheel speed of the most gripping wheel i. Therefore, it is possible to prevent the estimated vehicle body speed from deviating from the actual vehicle body speed.

  The deviation calculating means 21 may calculate the reference wheel angular acceleration based on a value obtained by dividing the sum of braking / driving forces of all the wheels 1 to 4 by the vehicle weight. In this case, for example, the number of parts can be reduced and the cost can be reduced as compared to calculating the reference wheel angular acceleration based on the value detected by the longitudinal acceleration sensor 24.

  A longitudinal acceleration sensor 24 for detecting the longitudinal acceleration of the vehicle may be provided, and the deviation calculating means 21 may calculate the reference wheel angular acceleration based on the longitudinal acceleration detected by the longitudinal acceleration sensor 24.

  The vehicle includes a motor 6 as the braking / driving force generation means. The motor 6 is an in-wheel motor that is partially or entirely disposed in a wheel and includes the motor 6, a wheel bearing 16, and a speed reducer 15. The drive device IWM may be configured.

  The vehicle body speed estimation device for a vehicle according to the present invention is a vehicle speed estimation device that estimates the vehicle body speed from the wheel speed of each wheel in a vehicle having braking / driving force generation means capable of generating a driving force and a braking force on all wheels. A determination means for determining whether the absolute value of the braking / driving force of all the wheels is equal to or greater than a threshold value and whether the positive / negative is mixed for the braking / driving force of all the wheels, and the determination means, When it is determined that the absolute value of the braking / driving force of all the wheels is equal to or greater than the threshold value, and the braking / driving force of all the wheels is a mixture of positive and negative, the wheel speed is the lowest of the wheels with positive braking / driving force. Deviation calculating means for extracting a wheel and a wheel having the highest wheel speed out of wheels having a negative braking / driving force, and calculating a deviation between the wheel angular acceleration and the reference wheel angular acceleration for each of the extracted two wheels; , Each of these deviation calculation means Of the deviations, it provided a vehicle body speed estimating means for estimating a vehicle speed according to the criteria defined by the absolute value smaller wheel speed of the wheels. For this reason, when driving force is generated on at least one wheel, the vehicle body speed can be accurately estimated from the wheel speed in a vehicle capable of generating braking force on at least one other wheel.

1 is a diagram schematically illustrating a system configuration of a vehicle body speed estimation device according to an embodiment of the present invention in a plan view. It is sectional drawing of the in-wheel motor drive device of the vehicle. It is a block diagram of a control system of the vehicle body speed estimation device. It is a figure which shows the example which estimates vehicle body speed according to the braking / driving force of the vehicle. It is a flowchart of estimation of the vehicle body speed estimation apparatus. It is a figure which shows schematically the system configuration | structure of the vehicle body speed estimation apparatus of the vehicle which concerns on other embodiment of this invention by planar view.

A vehicle body speed estimation apparatus according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram schematically showing the system configuration of the vehicle body speed estimation device 5 of this vehicle in plan view. The vehicle body speed estimation device 5 is a device that estimates the vehicle body speed from the wheel speed of each wheel. In this embodiment, as a vehicle on which the vehicle body speed estimation device 5 is mounted, the left and right front wheels 1 and 2 and the rear wheels 3 and 4 are each independently driven by a motor 6 that is a braking / driving force generating means. Independent drive vehicles are applied. Each wheel 1 to 4 includes a motor 6 and a wheel speed sensor 7 that detects the rotational speed of the wheel. Each motor 6 constitutes an in-wheel motor drive device IWM described later.

  The vehicle control system includes an ECU 8 that includes a vehicle body speed estimation device 5, a host ECU 9 that is a higher-level control means than the ECU 8, and an inverter device 10. The ECU 8 and the host ECU 9 are each composed of a computer, a program executed by the computer, various electronic circuits, and the like. The host ECU 9 is, for example, an electric control unit that performs cooperative control and overall control of the entire vehicle, and is provided with torque distribution means 9a.

  The torque distribution means 9a receives an acceleration command from the accelerator operation means 11 and a deceleration command from the brake operation means 12, and sends a braking / driving command corresponding to the difference between the acceleration command and the deceleration command to the ECU 8 and each inverter. Distribute to device 10. The braking / driving command is, for example, a torque command.

  The inverter device 10 includes a power circuit unit 10a provided for each motor 6 and a motor control unit 10b that controls the power circuit unit 10a. Each power circuit unit 10a can be independently controlled so that the motor torque is different from each other. The motor control unit 10b has a function of outputting information such as detection values and control values related to the in-wheel motor drive device IWM to the ECU 8, for example.

  The motor control unit 10b converts it into a current command according to the braking / driving torque command value given from the ECU 8, and gives the current command to the PWM driver of the power circuit unit 10a. The inverter devices 10 and 10 corresponding to the left and right front wheel driving motors 6 and 6 are accommodated in, for example, one housing on the vehicle body 13. The same applies to the inverter devices 10 and 10 corresponding to the motors 6 and 6 for driving the left and right rear wheels.

  FIG. 2 is a cross-sectional view of the in-wheel motor drive device IWM. Each in-wheel motor drive unit IWM includes a motor 6, a speed reducer 15, and a wheel bearing 16, and a part or all of these are arranged in the wheel. The rotation of the motor 6 is transmitted to the wheels 1 (2-4) via the speed reducer 15 and the wheel bearing 16. A brake rotor 17 is fixed to the flange portion of the hub wheel 16a of the wheel bearing 16, and the brake rotor 17 rotates integrally with the wheels 1, (2 to 4). The motor 6 is, for example, an embedded magnet type synchronous motor in which a permanent magnet is built in the core portion of the rotor 6a. The motor 6 is a motor in which a radial gap is provided between a stator 6 b fixed to a housing 18 and a rotor 6 a attached to the rotation output shaft 19.

  FIG. 3 is a block diagram of a control system of the vehicle body speed estimation device 5. Hereinafter, description will be made with reference to FIG. 1 as appropriate. The ECU 8 is provided with a vehicle body speed estimation device 5, and the vehicle body speed estimation device 5 includes a determination unit 20, a deviation calculation unit 21, a vehicle body speed estimation unit 22, and a storage unit 23. The determination means 20 estimates the braking / driving force acting on each wheel, and determines whether the absolute values of these braking / driving forces are each equal to or greater than a threshold value. Furthermore, the determination means 20 determines the positive / negative of the braking / driving force of each wheel. In the wheel, the braking / driving force is determined as “positive” when the driving force is generated, and the braking / driving force is determined as “negative” when the braking force is generated.

ただし、Ｉは車輪の慣性モーメント、ｒはタイヤ半径であり、ｉは車輪番号（ｉ＝１，…，４）である。モータコントロール部１０ｂは、例えば、電流検出手段Ｓａから得られるモータ電流値を得て、各車輪のモータトルクＴ_ｉを推定する。モータトルクＴ_ｉはモータ電流と比例関係にあるからである。 From the wheel speed ω _i of each wheel and the torque T _{i applied} to each wheel, the braking / driving force F _i acting on each wheel is estimated by the following equation (1). Each wheel speed ω _i is obtained from each wheel speed sensor 7.

Here, I is the inertia moment of the wheel, r is the tire radius, and i is the wheel number (i = 1,..., 4). Motor control unit 10b, for example, with the motor current value obtained from the current detection means Sa, estimates the motor torque T _i of each wheel. This is because the motor torque _Ti is proportional to the motor current.

The judging means 20, when the absolute value of the longitudinal force F _i is determined to wheel less than the threshold value A is present, determines that the wheel is less than the threshold A is gripping, vehicle speed estimating means 22, the The vehicle body speed V is estimated from the wheel speed ω _i of the wheel according to the following equation (2). The threshold value A is determined by, for example, a result of a test or simulation, and is stored in the storage unit 23 so as to be rewritable.
V = rω _i (2)

When the determination means 20 determines that the absolute value of the braking / driving force F _i of all the wheels is equal to or greater than the threshold value A and the braking / driving force F _i of all these wheels is “negative”, all the wheels Is determined to have a locking tendency. In this case, the vehicle body speed estimation means 22 multiplies the wheel speed ω _max (= Max (ω _i )) of the wheel having the highest wheel speed closest to the grip state by the tire radius r of the wheel to obtain the vehicle body speed V Is estimated.

When the determination means 20 determines that the absolute values of the braking / driving forces F _i of all the wheels are equal to or greater than the threshold value A and the braking / driving forces F _i of all the wheels are “positive”, all the wheels Is determined to have a spin tendency. In this case, the vehicle body speed estimation means 22 multiplies the wheel speed ω _min (= Min (ω _i )) of the wheel having the lowest wheel speed closest to the grip state by the tire radius r of the wheel to obtain the vehicle body speed V Is estimated.

If the determination means 20 determines that the absolute value of the braking / driving force F _i of all the wheels is greater than or equal to the threshold value A and “positive / negative” is mixed for the braking / driving force F _i of all the wheels, the lock tendency Judge that wheels and wheels with a spin tendency are mixed. In this case, the deviation calculating means 21, the longitudinal force F _i and the wheel of the wheel speed of the wheels of the "positive" is a minimum value, the longitudinal force F _i is the maximum value of the wheel speed of the wheels of the "negative" Extract the wheels.

図４は、この車両の制駆動力に応じて車体速度を推定する例を示す図である。同図４において、車輪１〜４に付した矢印のうち、前向きの矢印は駆動力（制駆動力は「正」）を表し、後向きの矢印は制動力（制駆動力は「負」）を表す。図３も参照しつつ説明する。図４（ａ）に示すように、判定手段２０により、全ての車輪１〜４の制駆動力の絶対値が閾値以上で、且つ、これら全ての車輪１〜４の制駆動力につき正負が混在すると判定されたとき、偏差算出手段２１により算出対象となる二つの車輪を抽出する。

FIG. 4 is a diagram illustrating an example of estimating the vehicle body speed according to the braking / driving force of the vehicle. In FIG. 4, among the arrows attached to the wheels 1 to 4, a forward arrow indicates a driving force (braking / braking force is “positive”), and a rearward arrow indicates a braking force (braking / braking force is “negative”). Represent. This will be described with reference to FIG. As shown in FIG. 4A, the absolute value of the braking / driving force of all the wheels 1 to 4 is greater than or equal to the threshold value, and the positive / negative is mixed for the braking / driving force of all the wheels 1 to 4 as shown in FIG. Then, when it is determined, the deviation calculating means 21 extracts two wheels to be calculated.

  The deviation calculating means 21 includes a wheel 3 (for example, the left rear wheel) having the lowest wheel speed among the wheels 1 and 3 having a positive braking / driving force (the left front wheel and the left rear wheel in FIG. 4A), and the braking / driving force. Of the wheels 2 and 4 having a negative driving force (the right front wheel and the right rear wheel in FIG. 4A), the wheel 2 having the highest wheel speed (for example, the right front wheel) is extracted. The deviation calculating means 21 calculates the deviation for each of the extracted two wheels 3 and 2 by the above-described equation (3). The vehicle body speed estimation means 22 estimates the vehicle body speed V from the wheel speeds of the wheels 3 and (2) having the smaller absolute value among the calculated deviations according to the equation (2).

  As shown in FIG. 4B, when the determination means 20 determines that there is a wheel 2 (for example, the right front wheel) whose absolute value of braking / driving force is less than the threshold, the vehicle body speed estimation means 22 The vehicle body speed V is estimated from the wheel speed according to the equation (2).

  As shown in FIG.4 (c), the absolute value of the braking / driving force of all the wheels 1-4 is more than a threshold value by the determination means 20, and the braking / driving force of all these wheels 1-4 is negative. Is determined, the vehicle body speed estimation means 22 estimates the vehicle body speed V from the wheel speed of the wheel 1 (for example, the left front wheel) having the highest wheel speed according to the equation (2).

As shown in FIG.4 (d), the absolute value of the braking / driving force of all the wheels 1-4 is more than a threshold value by the determination means 20, and the braking / driving force of all these wheels 1-4 is positive. Is determined, the vehicle body speed estimation means 22 estimates the vehicle body speed V from the wheel speed of the wheel 4 (for example, the right rear wheel) having the lowest wheel speed according to the equation (2).
Using the vehicle body speed estimated as described above, for example, in the traction control device and the antilock brake control device, the slip ratio control can be performed with high accuracy.

FIG. 5 is an estimation flowchart of the vehicle body speed estimation apparatus. This will be described with reference to FIGS. For example, this process starts after the main power of the vehicle is turned on, and the determination means 20 obtains the motor torque T _i of each wheel 1 to 4 estimated from each current detection means Sa and each wheel speed sensor 7. The obtained wheel speed ω _i is read (step S1). Next, the determination means 20 estimates the braking / driving force F _i acting on each of the wheels 1 to 4 using the equation (1) (step S2). These braking / driving forces F _i are temporarily stored in the storage means 23, for example.

Next, the determination unit 20 compares the relationship between the absolute value | F _i | of all braking / driving forces and the threshold value A (step S3). When it is determined that there is a wheel 1, (2-4) whose absolute value | F _i | of the braking / driving force is less than the threshold A (step S3: Yes), the vehicle body speed estimation means 22 determines that the wheel 1, (2-2) The vehicle body speed is estimated from the wheel speed ω _{i of} 4) (step S4). Thereafter, this process is terminated.

It is determined that the absolute value | F _i | of the braking / driving force of all the wheels 1 to 4 is equal to or greater than the threshold A (step S3: No), and the braking / driving force F _i of all the wheels 1 to 4 is “negative” Is determined (step S5: Yes), the vehicle body speed estimation means 22 estimates the vehicle body speed from the wheel speed ω _max (= Max (ω _i )) of the wheel having the highest wheel speed (steps S6, S7). ). Thereafter, this process is terminated.

If it is determined that the absolute values | F _i | of the braking / driving forces of all the wheels 1 to 4 are equal to or greater than the threshold A and the braking / driving forces F _i of all the wheels 1 to 4 are “positive” (step) (S8: Yes), the vehicle body speed estimation means 22 estimates the vehicle body speed from the wheel speed ω _min (= Min (ω _i )) of the wheel having the lowest wheel speed (steps S9, S10). Thereafter, this process is terminated.

When it is determined that “positive / negative” is mixed for the braking / driving forces F _i of all the wheels 1 to 4 (step S8: No), the deviation calculating unit 21 determines the wheel speed for the wheel i satisfying the braking / driving force F _i > 0. Wheel speed ω _min (= Min (ω _i )) of the wheel having the lowest value is extracted (step S11), and the wheel speed ω _max of the wheel having the highest wheel speed for the wheel i satisfying the braking / driving force F _i <0 is extracted. (= Max (ω _i )) is extracted (step S12).

  Next, the deviation calculating means 21 calculates a reference wheel angular acceleration (step S13), and calculates a deviation between the wheel angular acceleration and the reference wheel angular acceleration for each of the extracted two wheels (step S14). Next, the deviation calculating means 21 estimates the vehicle body speed from the wheel speed of the wheel i having the smaller absolute value among the calculated deviations (step S15). Thereafter, this process is terminated.

The effect will be described.
In the control of the present embodiment, the grip, lock tendency or spin tendency of the wheels 1 to 4 is determined using the braking / driving force. Therefore, even in a transient state where the rotational angular acceleration of the wheels 1 to 4 is large, The grip, lock tendency or spin tendency can be accurately determined. When there is a gripping wheel i among all the wheels 1 to 4, the vehicle body speed is estimated from the wheel speed. When slipping of all the wheels 1 to 4 is large and tends to be locked or spin, the vehicle body speed is estimated from the wheel i closest to the grip state.

Even in the case where a wheel having a rock tendency and a wheel having a spin tendency are mixed, by estimating the vehicle body speed from the wheel speed of the wheel i having a small deviation from the reference wheel angular acceleration, the wheel i having the highest possibility of the smallest slip. The vehicle speed can be estimated from the wheel speed.
As described above, the vehicle body speed is estimated from the wheel speed of the wheel with the smallest slip even when grip, lock tendency, and spin tendency wheels coexist, so that the vehicle body speed can be estimated with higher accuracy than the conventional example.

Another embodiment will be described.
In the following description, the same reference numerals are given to the portions corresponding to the matters described in the preceding forms in each embodiment, and the overlapping description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in advance unless otherwise specified. The same effect is obtained from the same configuration. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  The in-wheel motor drive device IWM is a so-called direct motor type in which a cycloid reducer, a planetary reducer, a two-axis parallel reducer, and other reducers can be applied. Also good.

  In this embodiment, the four-wheel drive vehicle provided with the motor 6 on each of the wheels 1 to 4 has been described as the vehicle, but is not limited to this example. For example, as a vehicle, a two-wheel drive vehicle provided with a motor 6 on each of the left and right of the front wheels 1 and 2 or the rear wheels 3 and 4, or as shown in FIG. This control can also be applied to a so-called three-motor four-wheel drive vehicle in which both left and right wheels are driven by one motor 6 and one motor 6 is provided for each of the other left and right wheels 3 and 4. Further, the vehicle may be applied not only to a four-wheeled vehicle but also to a three-wheeled vehicle, and the left and right two wheels or all the wheels in the three-wheeled vehicle may be driven independently.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1-4 ... wheel 5 ... body speed estimation device 6 ... motor (braking / driving force generating means)
DESCRIPTION OF SYMBOLS 15 ... Reducer 16 ... Wheel bearing 20 ... Determination means 21 ... Deviation calculation means 22 ... Vehicle body speed estimation means 24 ... Longitudinal acceleration sensor IWM ... In-wheel motor drive device

Claims (7)

In a vehicle having braking / driving force generating means capable of generating a driving force and a braking force on all wheels, a vehicle body speed estimating device for estimating a vehicle body speed from a wheel speed of each wheel,
A determination means for determining whether the absolute value of the braking / driving force of all the wheels is equal to or greater than a threshold value and whether the positive / negative is mixed for the braking / driving force of all the wheels;
When it is determined by this determination means that the absolute value of the braking / driving force of all the wheels is equal to or greater than the threshold value and the positive / negative is mixed for the braking / driving force of all the wheels, the wheel of the positive / negative braking force is the wheel The wheel with the lowest speed and the wheel with the highest wheel speed out of the wheels with negative braking / driving force are extracted, and the difference between the wheel angular acceleration and the reference wheel angular acceleration is calculated for each of the two extracted wheels. Deviation calculating means for
Vehicle body speed estimating means for estimating the vehicle body speed according to a standard determined from the wheel speed of the wheel having the smaller absolute value among the deviations calculated by the deviation calculating means;
A vehicle body speed estimation device characterized by comprising:   The vehicle body speed estimation device according to claim 1, wherein the determination unit has a function of determining whether or not there is a wheel having an absolute value of braking / driving force less than a threshold value. When it is determined that there is a wheel whose absolute value of driving force is less than the threshold, the vehicle body speed estimation means estimates the vehicle body speed according to a standard determined from the wheel speed of the wheel less than the threshold. .   3. The vehicle body speed estimation device according to claim 1 or 2, wherein the determination means has an absolute value of braking / driving force of all wheels equal to or greater than a threshold value and negative braking / driving force of all the wheels. The determination means determines that the absolute value of the braking / driving force of all the wheels is greater than or equal to the threshold value, and that the braking / driving force of all these wheels is negative. Then, the vehicle body speed estimation means estimates the vehicle body speed according to a reference determined from the wheel speed of the wheel having the highest wheel speed.   The vehicle body speed estimation device according to any one of claims 1 to 3, wherein the determination means has an absolute value of braking / driving force of all wheels equal to or greater than a threshold value, and all of the wheels. A function for determining whether the braking / driving force is positive or not, and the determination means determines that the absolute value of the braking / driving force of all the wheels is equal to or greater than a threshold value, and that the braking / driving force of all the wheels is positive. When it is determined that the vehicle body speed is estimated, the vehicle body speed estimation means estimates the vehicle body speed according to a reference determined from the wheel speed of the wheel having the lowest wheel speed.   The vehicle body speed estimation device according to any one of claims 1 to 4, wherein the deviation calculating means is configured to calculate the norm based on a value obtained by dividing a sum of braking / driving forces of all wheels by a vehicle weight. A vehicle body speed estimation device for calculating wheel angular acceleration.   5. The vehicle body speed estimation device according to claim 1, further comprising a longitudinal acceleration sensor that detects longitudinal acceleration of the vehicle, wherein the deviation calculating means is detected by the longitudinal acceleration sensor. A vehicle body speed estimation device for calculating the reference wheel angular acceleration based on longitudinal acceleration. The vehicle body speed estimation device according to any one of claims 1 to 6, wherein the vehicle includes a motor as the braking / driving force generation means, and the motor is partially or entirely in the wheel. A vehicle body speed estimation device that is disposed and constitutes an in-wheel motor drive device including the motor, a wheel bearing, and a reduction gear.

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