JP3412363B2 - Vehicle body speed estimation device and wheel free rotation speed 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 an apparatus for estimating a vehicle body speed and a free wheel rotation speed of a vehicle such as an automobile.

[0002]

2. Description of the Related Art As described in, for example, Japanese Patent Publication No. 5-502836, the specification of a vehicle is made based on the detected wheel speed and yaw rate of a specific wheel within the linear range of the μ-S characteristic when the vehicle is being braked. A technique for obtaining the speed of the position of the vehicle and using this as the vehicle body speed has been conventionally known, and the free rotation speed of each wheel (the rotation speed in the unbraked state is calculated from the vehicle speed and yaw rate calculated in this way). ) Is also known in the art.

According to such a technique, the vehicle body speed and the free rotation speed of each wheel are more accurately compared with the case where the wheel speed of each wheel is detected and the vehicle body speed is simply calculated as an average value of those wheel speeds. Therefore, the control of the vehicle based on these speeds can be performed well.

[0004]

However, in the above technique, it is necessary to confirm whether or not a particular wheel is within the range of the straight line of the μ-S characteristic, and the wheel has the μ-S characteristic. If it is not within the range of the straight line, the braking pressure of the wheel must be reduced, which may hinder the desired braking force control.

The present invention has been made in view of the above-mentioned problems in the conventional device, and the main object of the present invention is to determine the vehicle body speed depending on whether or not the control of the braking force is executed. Whether the wheel is within the range of the straight line of the μ-S characteristic by weighting the speed that is the basis of the calculation and appropriately selecting the speed that is the basis of the vehicle speed calculation according to the acceleration state of the vehicle. In spite of this, the vehicle body speed of the vehicle and the free rotation speed of the wheels are accurately estimated.

[0006]

According to the present invention, a main object as described above is a vehicle body speed estimating device for a vehicle equipped with a braking force control device for controlling the braking force of wheels as necessary. Means for detecting the wheel speed Vwi of each wheel, means for detecting a parameter indicating the turning state of the vehicle, and before and after calculating the wheel speed Vwi and the longitudinal speed Vri of a specific position of the vehicle for each wheel based on the parameters. Based on whether or not the control of the braking force by the speed calculation means and the braking force control device is being executed, the longitudinal velocity Vri of each wheel is calculated.
Of the vehicle body speed estimating apparatus (composition of claim 1), or means for calculating the vehicle body speed Vx based on the longitudinal speed Vri and the weight Wi. A vehicle body speed estimation device having a braking force control device for controlling the braking force of the wheels according to the above, and means for detecting the wheel speed Vwi of each wheel and means for detecting a parameter indicating the turning state of the vehicle. , Dynamic load of each wheel
A means for detecting a change in radius, a front-rear speed calculating means for calculating a front-rear speed Vri at a specific position of the vehicle for each wheel based on the change in the wheel speed Vwi , the parameter and the dynamic load radius, and an acceleration state of the vehicle. Detecting means, selecting means for selecting any one of the longitudinal speed Vri, and vehicle speed V based on the longitudinal speed selected by the selecting means.
and a means for calculating x, wherein the selecting means selects the longitudinal velocity Vri calculated for the wheel with the smallest acceleration slip when the vehicle is in an accelerating state. Thus it is achieved in the section 2 of the configuration).

According to the first aspect of the invention, the front-rear velocity Vri at a specific position of the vehicle is calculated for each wheel based on the wheel speed Vwi of each wheel and the parameter representing the turning state of the vehicle.
Whether the braking force is controlled by the braking force controller
Based on whether, computed weights Wi of longitudinal velocity Vri for each wheel in accordance with the reliability of every case which may be a basis for vehicle speed calculating other words, the vehicle speed Vx is calculated based on longitudinal velocity Vri and weight Wi Therefore, the braking force control device
Vehicle speed of the vehicle is correctly estimated even when the braking force of the wheels that are controlled.

According to the second aspect of the invention , the wheel speed Vwi of each wheel, the parameter indicating the turning state of the vehicle, and each wheel
For each wheel on the basis of the change in the dynamic load radius is longitudinal speed Vri is operational at a particular position of the vehicle, any one of the previous post-speed Vri is selected as the vehicle speed Vx, the acceleration slip, especially when the vehicle is in the accelerating state Since the longitudinal velocity Vri calculated for the smallest wheel is selected , turning of the vehicle
And during acceleration and deceleration
Front-rear velocity Vri without being affected by changes in dynamic load radius
Is calculated and the vehicle body speed of the vehicle is accurately estimated as compared with the case where the longitudinal speed Vri is selected without considering whether or not the vehicle is in an accelerated state.

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

Generally, in controlling a vehicle, the speed at the center of gravity of the vehicle is important as the speed of the vehicle, and the speed at other positions of the vehicle is the speed at the center of gravity of the vehicle. Can be obtained relatively easily. Therefore, in the above-mentioned structure of claim 1 or 2, the longitudinal speed Vri
Is configured to be calculated as the longitudinal velocity of the center of gravity of the vehicle.

When the radius of each wheel in the stationary state is significantly different from the standard state due to the difference in tire air pressure or the static support load of each wheel, etc., the vehicle speed and the free rotation of each wheel are different. The speed cannot be calculated accurately. Therefore, in the above-mentioned structure of claim 2 , there is provided a means for obtaining a static correction coefficient for the radius of each wheel in a stationary state of the vehicle,
The longitudinal speed calculation means is configured to calculate the longitudinal speed Vri based on the wheel speed Vwi, the parameter, the change in the dynamic load radius, and the static correction coefficient.

Further, in a vehicle equipped with a braking force control device for controlling the turning behavior of the vehicle and the acceleration / deceleration slip of the wheels, the braking force control device controls the braking force of each wheel as necessary. Therefore whether or not the control of the braking force of the above-described in the braking force control device to the first aspect is running Ru is determined based on information from the brake force control apparatus.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing a first embodiment of an estimation device according to the present invention applied to a vehicle equipped with a behavior control device for controlling the braking force of each wheel to stabilize the turning behavior of the vehicle. It is (A) and a block diagram (B).

In FIG. 1A, the wheel speed Vwi (i = fr, fl, rr, rl) of the wheels corresponding to the right front wheel 10fr, the left front wheel 10fl, the right rear wheel 10rr, and the left rear wheel 10rl, respectively. Wheel speed sensors 12fr, 12fl, 12r
r and 12rl are provided, and a signal indicating the wheel speed Vwi is input to the estimation device 14. Further, the estimation device 14 has a signal indicating the steering angle θ from the steering angle sensor 16, a signal indicating the longitudinal acceleration Gx of the vehicle body from the longitudinal acceleration sensor 18 provided substantially at the center of gravity of the vehicle, and a lateral acceleration sensor 20 indicating the lateral direction of the vehicle body. A signal indicating the acceleration Gy and a signal indicating the yaw rate γ of the vehicle are input from the yaw rate sensor 22. The longitudinal acceleration sensor 18 detects the longitudinal acceleration with the forward direction of the vehicle as positive, and the lateral acceleration sensor 20 etc. detects the lateral acceleration with the left turning direction of the vehicle as positive.

Although not shown in detail in FIG. 1, the estimation device 14 includes a central processing unit (CPU), a read only memory (ROM), and a random access memory (RA).
M) and an input / output port device, which have a general configuration in which these are connected to each other by a bidirectional common bus, and an estimation routine described later based on the parameters detected by the various sensors described above. The vehicle body speed Vb of the vehicle and the free rotation speed Vri of the wheels are calculated by performing various calculations in accordance with the above, and the vehicle body speed Vb and the vehicle body speed Vb of the vehicle body speed Vb A signal indicating the free rotation speed Vri is output.

The behavior control device 24 estimates the turning behavior of the vehicle based on the vehicle speed Vb and the free rotation speed Vri when the vehicle speed Vb is equal to or higher than a reference value Vc such as 15 km / h, and the turning behavior is a spin state. When the vehicle is on, braking force is applied to the turning outer wheels to give an anti-spin moment to the vehicle to stabilize the behavior of the vehicle, and when the turning behavior is drifting out, braking force is applied to the left and right rear wheels to decelerate the vehicle. In addition, the lateral force of the rear wheels is reduced and a turning assist moment is applied to the vehicle to stabilize the behavior of the vehicle.

Next, the outline of the routine for estimating and calculating the vehicle body speed and the free wheel rotation speed in the first embodiment will be described with reference to the flow charts shown in FIGS. The estimation calculation according to the flowcharts shown in FIGS. 2 and 3 is started by closing an ignition switch (not shown) and is repeatedly executed at predetermined time intervals.

First, at step 10, a signal indicating the wheel speed Vwi detected by the wheel speed sensors 12fl to 12rr is read, and at step 20, with T as the tread, the yaw rate is calculated according to the following equation 1. A speed difference Vyr between the speed at the wheel position and the speed at the center of gravity of the vehicle is calculated.

[Formula 1] Vyr = γ * (T / 2) * 3.6 * π / 180

In step 30, the steering angle δ of the front wheels is calculated according to the following equation 2 using Nsg as the steering gear ratio.

[Equation 2] δ = θ / Nsg

In step 40, W is the weight of the vehicle, H is the height of the center of gravity of the vehicle, and L is the wheel base, and the load movement amount ΔWgx of each wheel due to the longitudinal acceleration Gx is calculated according to the following equation (3).

[Formula 3] ΔWgx = Gx * W * H / L / 2

In step 50, the load movement amounts ΔWgyf and ΔWgyr of the front and rear wheels due to the lateral acceleration Gy are calculated according to the following equation 4 by using Gpf and Gpr as roll rigidity distributions on the front wheel side and the rear wheel side, respectively.

## EQU4 ## ΔWgyf = (Gy * W * H / T) * Gpf ΔWgyr = (Gy * W * H / T) * Gpr

In step 60, K is the tire stiffness and Rt is the tire radius, and the dynamic correction coefficient Kdi of the tire radius of each wheel due to load movement is calculated according to the following equation (5).

## EQU00005 ## Kdfr = 1 + {-. DELTA.Wgx + .DELTA.Wgyf} * 9.8
/ K / Rt Kdfl = 1 + {-ΔWgx-ΔWgyf} * 9.8 / K / R
t Kdrr = 1 + {ΔWgx + ΔWgyf} * 9.8 / K / Rt Kdrl = 1 + {ΔWgx−ΔWgyf} * 9.8 / K / Rt

In step 70, the longitudinal velocity V of the vehicle body at the center of gravity of the vehicle for each wheel is calculated according to the following equation 6.
ri is calculated.

[Equation 6] Vrfr = Kdfr * Vwfr * cos δ-Vyr Vrfl = Kdfl * Vwfl * cos δ + Vyr Vrrr = Kdrr * Vwrr-Vyr Vrrl = Kdrl * Vwrl + Vyr

In step 80, it is determined whether or not the longitudinal acceleration Gx of the vehicle is positive, that is, whether or not the vehicle is in an accelerating state, and if a positive determination is made, step 90 is entered. In this case, the minimum value of the longitudinal velocity Vri of the vehicle body is selected as the longitudinal velocity Vws, and when a negative determination is made, the maximum value of the longitudinal velocity Vri of the vehicle body is selected as the longitudinal velocity Vws in step 100.

In step 110, Vxf is the vehicle body speed obtained in step 110 one cycle before, and α1 and α2 are positive constants.
The vehicle speed Vx is calculated in accordance with the above. In the following expression 7, MED means selecting an intermediate value of the three numerical values in parentheses.

[Equation 7] Vx = MED [V w s, Vxf + α1, Vxf-α2]

In step 120, it is judged whether or not the vehicle speed Vx is less than the reference value Vc for behavior control. If a negative judgment is made, the routine proceeds to step 140, and if a positive judgment is made. In step 130, the vehicle body speed Vx is selected as the reference speed Vwsb for calculating the free rotation speed Vbi of each wheel.

In step 140, the behavior controller 2
In step 150, it is determined whether only the outer wheel on the turning side is being braked in order to reduce spin. When a positive determination is made, the vehicle body speed Vri of the front wheel on the turning inner wheel side is selected as the reference speed Vwsb in step 150. If a negative determination is made, the process proceeds to step 160. In step 160, the behavior control device 24 determines whether or not only the rear wheels are being braked in order to reduce drift-out. When a negative determination is made, the routine proceeds to step 130, where an affirmative determination is made. In step 170, the larger one of the vehicle speeds Vfr and Vrfl of the front wheels is selected as the reference speed Vwsb.

In step 180, step 13
Reference speed Vws selected at 0, 150 or 170
Free rotation speed Vbi of each wheel according to the following equation 8 based on b
Is calculated. In the following expression 8, MAX means selecting the larger value of the two values in the parentheses.

## EQU8 ## Vbfr = MAX [(Vwsb + Vyr) * cosδ *
Kdfr, 0] Vbfl = MAX [(Vwsb-Vyr) * cosδ * Kdfl,
0] Vbrr = MAX [(Vwsb + Vyr) * Kdrr, 0] Vbrl = MAX [(Vwsb-Vyr) * Kdrl, 0]

In step 190, the signals indicating the vehicle body speed Vx and the free wheel rotation speed Vbi calculated in steps 110 and 180 are the behavior control device 2.
4 is output.

Thus, in the first embodiment, the speed difference Vyr between the speed at the wheel position and the speed at the center of gravity of the vehicle due to the yaw rate is calculated in step 20, and in step 30. The steering angle δ of the front wheels is calculated,
In step 40, the load movement amount ΔWgx of each wheel due to the longitudinal acceleration Gx is calculated, and in step 50, the load movement amount ΔWgyf and Δ of the front and rear wheels due to the lateral acceleration Gy.
Wgyr is calculated, the dynamic correction coefficient Kdi of the tire radius of each wheel due to load movement is calculated in step 60, and in step 70, the wheel speed Vwi of each wheel and the turning state of the vehicle are set as parameters. Based on this, the longitudinal velocity Vri of the vehicle body at the center of gravity of the vehicle for each wheel is calculated.

Then, in step 80, it is judged whether or not the vehicle is in the accelerating state, and when the vehicle is in the accelerating state, in steps 90 and 110, the calculation is made for the wheel with 0 or the smallest acceleration slip. The longitudinal speed of the vehicle body is selected, and the vehicle speed V is determined based on the longitudinal speed.
x is obtained, and when the vehicle is not in an accelerating state, the longitudinal velocity of the vehicle body calculated in steps 100 and 110 for the wheel having zero deceleration slip or the smallest is selected.
At the same time , the vehicle body speed V x is obtained based on the longitudinal speed .

Therefore, according to the first embodiment, when the vehicle is in an accelerating state, the longitudinal velocity Vri calculated for the wheel that has not undergone the acceleration slip or the wheel with the smallest acceleration slip is selected and set as the longitudinal velocity. Based on vehicle speed
Is calculated , the vehicle body speed of the vehicle can be accurately estimated even when the vehicle is in an accelerating state.

According to the first embodiment, step 4
In 0 to 60, the dynamic correction coefficient Kdi of the tire radius of each wheel due to load movement is calculated, and in the calculation of the vehicle body longitudinal velocity Vri in step 70, the dynamic correction coefficient Kdi is considered. Therefore, as compared with the case where the change in tire radius of each wheel due to load movement is not taken into consideration, the front-rear velocity Vri of the vehicle body at the center of gravity of the vehicle is accurately calculated, and thereby the vehicle body speed Vx is accurately estimated. You can

According to the first embodiment, step 1
Vehicle In 20,140,160 is made determination of whether it is the behavior control, each wheel on the basis of the free wheel velocity Vri or vehicle speed V x the influence of the braking force control by the behavior control based on the determination result Since the free rotation speed Vbi of is calculated, the free rotation speed of each wheel can be accurately estimated even when the braking force of the wheel is controlled by the behavior control device.

FIG. 4 shows the present invention applied to a vehicle equipped with a behavior control device for controlling the braking force of each wheel to stabilize the turning behavior of the vehicle and an ABS device for controlling the braking force of each wheel so as not to lock. FIG. 2 is a schematic configuration diagram (A) and a block diagram (B) showing a second embodiment of the estimation device according to the present invention.

The estimation device 14 of this embodiment performs various calculations according to an estimation routine to be described later based on the parameters detected by various sensors as in the estimation device of the first embodiment. calculates the free rotation speed V b i speed Vb and the wheel, as well as outputs a signal indicating a vehicle speed Vb and the free rotational speed V b i to the behavior control device 24, a control so as not to lock the braking force of each wheel The vehicle body speed Vb and the free rotation speed V
It outputs a signal indicating b i.

Next, the outline of the routine for estimating and calculating the vehicle body speed and the free wheel rotation speed in the second embodiment will be described with reference to the flow chart shown in FIG. The estimation calculation according to the flow chart shown in FIG. 5 is also started by closing an ignition switch (not shown) and is repeatedly executed at predetermined time intervals.

First, at step 210, a signal indicating the wheel speed Vwi detected by the wheel speed sensors 12fl to 12rr is read, and at step 220, the steering angle δ of the front wheels is calculated according to the above equation 2. With A as the Ackermann ratio, T as the tread, and H as the height of the center of gravity of the vehicle, the steering angles δl and δr of the left front wheel and the right front wheel are calculated according to the following equation 9.

[Equation 9] δl = [1 + A {1+ (T * δ) / (2 * H)}] * δ δr = [1-A {1- (T * δ) / (2 * H)}] * δ

In step 230, the load movement amount ΔWgx of each wheel due to the longitudinal acceleration Gx is calculated according to the above equation 3, and in step 240, the load movement amount of the front wheel and the rear wheel due to the lateral acceleration Gy according to the above equation 4. ΔWgyf and ΔWgyr are calculated, and in step 250, the dynamic correction coefficient Kdi of the tire radius of each wheel due to the load movement is calculated according to the equation (5).

In step 260, the lateral acceleration Gy and the vehicle body speed Vx calculated in step 280 described later.
And the deviation of the yaw rate γ from the product Vx * γ Gy -Vx * γ
Is the deviation of the lateral acceleration, that is, the lateral slip acceleration of the vehicle Vyd
Is calculated, and the lateral slip velocity Vy of the vehicle body is calculated by integrating the deviation Vyd of the lateral acceleration, and the ratio Vy / Vx of the lateral slip velocity Vy of the vehicle body to the vehicle body speed Vx is calculated.
The slip angle β of the vehicle body at the center of gravity of the vehicle is calculated as

In step 270, the vehicle body speed Vri at the center of gravity of the vehicle for each wheel is calculated in accordance with the following equation 10 using Lf as the distance between the center of gravity and the axle of the front wheel. In Expression 10, Ksi is a static correction coefficient of the tire radius of each wheel calculated by the routine shown in FIG. 6 described later.

[Equation 10] Vrfr = {Ksfr * Kdfr * Vwfr + (T /
2) * γ * cos δr −Lf * γ * sin δr} / cos (β
−δr) Vrfl = {Ksfl * Kdfl * Vwfl + (T / 2) * γ *
cos δl −Lf * γ * sin δl} / cos (β−δl) Vrrr = {Ksrr * Kdrr * Vwrr + (T / 2) * γ}
/ Cos β Vrrl = {Ksrl * Kdrl * Vwrl + (T / 2) * γ}
/ Cos β

In step 280, the vehicle body speed Vx is calculated according to the following equation 11 based on the weight Wi of each wheel and the vehicle body speed Vri of each wheel calculated by the routine shown in FIG.

[Equation 11] Vx = (Wfr * Vrfr + Wfl * Vrfl + Wrr
* Vrrr + Wrl * Vrrl) / (Wfr + Wfl + Wrr + Wr
l)

In step 290, the free rotation speed Vbi of each wheel is calculated according to the following equation 12 based on the vehicle speed Vx.

## EQU12 ## Vbfr = Vx * cos (β-δr)-(T /
2) * γ * cos δr + Lf * γ * sin δr Vbfl = Vx * cos (β-δl) + (T / 2) * γ * co
s δl-Lf * γ * sin δr Vbrr = Vx * cos β- (T / 2) * γ Vbrl = Vx * cos β + (T / 2) * γ

In step 300, the signals indicating the vehicle body speed Vx and the free rotation speed Vbi of each wheel calculated in steps 280 and 290 are the behavior control device 2.
4 and the ABS device 26.

Next, the routine for calculating the weight Wi of each wheel and the static correction coefficient Ksi of the tire radius of each wheel will be described with reference to the flow chart shown in FIG. The routine shown in FIG. 6 is also repeatedly executed at predetermined time intervals, and steps 410 to 450 are executed for each wheel in a time series order, for example, the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel.

First, at step 410, it is determined whether or not the wheel is under the behavior control by the behavior control device 24, that is, whether or not the braking force control for the behavior control is being executed. When a negative determination is made, the routine proceeds to step 430, and when a positive determination is made, the weight Wi is set to Rvsc in step 420.

In step 430, the wheel is AB
Whether or not the S control is being performed, that is, whether or not the braking force control by the ABS device 26 is being performed,
When a positive determination is made, the weight Wi is set to Rabs in step 440, and when a negative determination is made, the weight Wi is set to Rnor in step 450. Rvsc, Rabs, and Rnor are constants that satisfy the following Expression 13.

[Equation 13] Rnor> Rabs> Rvsc = 0

In step 460, the weight Wi of each wheel is calculated according to the following equation 14 using Rf and Rr as coefficients (positive constants) for the front wheel and the rear wheel, respectively.
The coefficients Rf and Rr are Rf when the vehicle is a rear-wheel drive vehicle.
> Rr, and in the case of a front-wheel drive vehicle, Rf <Rr.

[Equation 14] Wfr = Wfr * Rf Wfl = Wfl * Rf Wrr = Wrr * Rr Wrl = Wrl * Rr

In step 470, the static correction coefficient Ksi of the tire radius of each wheel is calculated according to the following equation 15. In addition, R is a filter coefficient, and Ts is a sampling time, and Tr is Ts / Tr, where Tr is a positive constant of about several seconds. Vbi is the free rotation speed of each wheel calculated in step 290, and the static correction coefficient Ksi is set to 1 when this routine is first executed.

[Expression 15] Ksi = (1-R) * Ksi + R * Vbi / Vwi

Thus, in the second embodiment, the steering angles δr and δl of the front wheels are calculated in step 220, and the load movement amount ΔWgx of each wheel due to the longitudinal acceleration Gx is calculated in step 230. In step 240, the load movement amount ΔWgy of the front and rear wheels due to the lateral acceleration Gy
f and ΔWgyr are calculated, and in step 250, the dynamic correction coefficient Kdi of the tire radius of each wheel caused by the load movement is calculated.
Is calculated, and the slip angle β of the vehicle body is calculated in step 260, and in step 270, the vehicle body at the center of gravity of the vehicle for each wheel is calculated based on the wheel speed Vwi of each wheel and the parameter indicating the turning state of the vehicle. The front-rear velocity Vri of V is calculated.

Then, in steps 410 to 460, the weight Wi is calculated according to the braking state of the wheels, and step 2
Vehicle speed V x on the basis of the longitudinal velocity Vri and the weight Wi of the vehicle body at 80 is calculated, the free rotational speed Vbi of each wheel based on the vehicle speed V x is calculated.

[0059] Therefore, according to this second embodiment, the weights Wi are calculated as the reliability of the time if that may be a basis of the vehicle speed calculated based on the braking state of the wheel, as the weight average of the longitudinal velocity Vri-based weight Wi Since the vehicle body speed Vx is calculated, the vehicle body speed of the vehicle and the free rotation speed of each wheel can be accurately estimated even when the braking force of the wheel is controlled by the behavior control or the ABS control .

Further, according to the second embodiment, in addition to the dynamic correction coefficient Kdi of the tire radius of each wheel due to the load movement, the static correction coefficient Ksi of the tire radius of each wheel is calculated in step 470. Since both the dynamic correction coefficient Kdi and the static correction coefficient Ksi are taken into consideration in the calculation of the vehicle body front-rear speed Vri in step 270, each wheel is affected by a change in tire air pressure or the like. Even when the tire radius is different from the standard state, the longitudinal velocity Vri of the vehicle body at the center of gravity of the vehicle is calculated more accurately than in the case of the first embodiment, whereby the vehicle body velocity Vx and the freedom of each wheel are calculated. The rotation speed can be accurately estimated.

Further, according to the second embodiment, the Ackermann ratio A is taken into consideration when calculating the steering angle of the front wheels, and the steering angles of the left and right front wheels are accurately calculated. Compared with the case, the front-rear velocity Vri of the vehicle body at the center of gravity of the vehicle is accurately calculated, and the vehicle body velocity Vx and
The free rotation speed of each wheel can be accurately estimated.

The above-described first embodiment is an embodiment applied to a vehicle in which only the behavior control device is installed, but is applied to a vehicle in which an ABS control device or a TRC device is installed in addition to the behavior control device. If so, step 16
If a negative determination is made at 0, it is determined whether ABS control or TRC control is in progress, and the ABS control
When it is determined that the control is being performed, the maximum of Vri of the wheels that are not under ABS control is selected as Vwsb, and when it is determined that the TRC control is being performed, T
The minimum value of Vri of wheels that are not RC controlled is Vws
If b is selected and neither ABS control nor TRC control is executed, the process may proceed to step 130.

In the second embodiment described above, the free rotation speed Vbi of each wheel is calculated in step 290 based on the vehicle body speed Vx calculated in step 280. However, even in this embodiment, the free rotation speed of each wheel is determined by the step 12 in the first embodiment.
It may be calculated according to the same routine as 0 to 180.

Although the present invention has been described above in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are also possible within the scope of the present invention. It will be apparent to those skilled in the art that

[0065]

As is apparent from the above description, according to the configuration of claim 1 of the present invention, the specific position of the vehicle for each wheel is determined based on the wheel speed Vwi of each wheel and the parameter indicating the turning state of the vehicle. before and after speed Vri is calculated, the braking force system
Reliability based on whether or not the control of the braking force by the control device is executed , in other words, the basis of vehicle speed calculation
Time for each wheel in accordance with the case that the weight Wi of the longitudinal velocity Vri is calculated, and since the vehicle speed Vx based on longitudinal velocity Vri and weight Wi is calculated, control of the wheel by the braking force control unit
It is possible to accurately estimate the vehicle body speed of the vehicle even when the power is that is controlled.

According to the second aspect of the invention , the wheel speed Vwi of each wheel, the parameter indicating the turning state of the vehicle, and the wheel
The front-rear velocity Vri at a specific position of the vehicle is calculated for each wheel based on the change in the dynamic load radius, and when the vehicle is in an accelerating state, the front-rear velocity Vri calculated for the wheel with the smallest acceleration slip is selected. is any one the selection of Vri, since the vehicle speed Vx based on the longitudinal velocity that is selected is calculated, which is also the time of turning and acceleration of the vehicle
Of the dynamic load radius of the wheel due to the load transfer caused by
The front-rear velocity Vri can be calculated without being affected.
In addition, the vehicle body speed of the vehicle can be accurately estimated as compared with the case where the longitudinal speed Vri is selected without considering whether or not the vehicle is in the accelerated state.

[0067]

[0068]

[0069]

[0070]

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an estimation device according to the present invention applied to a vehicle equipped with a behavior control device for controlling a braking force of each wheel and stabilizing a turning behavior of the vehicle (A). ) And a block diagram (B).

FIG. 2 is a flowchart showing a first half of an estimation calculation routine of a vehicle body speed and a free wheel rotation speed in the first embodiment.

FIG. 3 is a flowchart showing a latter half of a routine for estimating and calculating a vehicle body speed and a free wheel rotation speed in the first embodiment.

FIG. 4 is an estimation according to the present invention applied to a vehicle equipped with a behavior control device that controls the braking force of each wheel to stabilize the turning behavior of the vehicle and an ABS device that controls so that the braking force of each wheel is not locked. It is the schematic block diagram (A) and block diagram (B) which show 2nd embodiment of an apparatus.

FIG. 5 is a flowchart showing a routine for estimating and calculating a vehicle body speed and a free wheel rotation speed in the second embodiment.

FIG. 6 is a flow chart showing a calculation routine of a dynamic correction coefficient Kdi and a static correction coefficient Ksi of a tire radius of each wheel in the second embodiment.

[Explanation of symbols]

12fr, 12fl, 12rr, 12rl ... Wheel speed sensor 14 ... Estimating device 16 ... Steering angle sensor 18 ... longitudinal acceleration sensor 20 ... Lateral acceleration sensor 22 ... Yaw rate sensor 24. Behavior control device 26 ... ABS device

Continuation of the front page (56) References JP-A-2-70945 (JP, A) JP-A-1-254463 (JP, A) JP-A-1-202565 (JP, A) JP-A-5-105056 (JP , A) JP-A-6-321085 (JP, A) JP-A-2-303963 (JP, A) JP-A-4-201658 (JP, A) JP-A-62-125944 (JP, A) JP-A- 61-71265 (JP, A) JP-A-4-50068 (JP, A) JP-A-2-310157 (JP, A) JP-A-56-90754 (JP, A) JP-A-4-143158 (JP, A) Special table HEI 5-502836 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60T 8/66 B60T 8/24 B60T 8/58

Claims (2)

(57) [Claims] 1. A vehicle body speed estimating device equipped with a braking force control device for controlling the braking force of wheels as necessary, and means for detecting the wheel speed Vwi of each wheel, and a turning state of the vehicle. A parameter detecting means, a front-rear speed calculating means for calculating a front-rear speed Vri at a specific position of the vehicle for each wheel based on the wheel speed Vwi and the parameter, and a braking force control by the braking force control device are executed. The weight W of the front-rear speed Vri for each wheel based on whether
means for calculating i, the longitudinal velocity Vri and the weight W
and a means for calculating a vehicle speed Vx based on i. 2. A vehicle body speed estimating device equipped with a braking force control device for controlling braking force of wheels as required, and means for detecting a wheel velocity Vwi of each wheel, and a turning state of the vehicle. The means to detect the parameters and the dynamic load radius of each wheel
Means for detecting a change , front-rear speed calculating means for calculating a front-rear speed Vri at a specific position of the vehicle for each wheel based on the change in the wheel speed Vwi , the parameter and the dynamic load radius, and an acceleration state of the vehicle are detected. Means for selecting one of the longitudinal speeds Vri, and means for calculating the vehicle body speed Vx based on the longitudinal speeds selected by the selecting means. The selecting means accelerates the vehicle. A vehicle body speed estimation device for a vehicle, characterized in that when the vehicle is in a state, the longitudinal speed Vri calculated for the wheel with the smallest acceleration slip is selected.