JP2003118558A - Estimating device of car body yaw rate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy in estimating a yaw rate. SOLUTION: This estimating device comprises a steering angle sensor 1, wheel speed sensors 5a, 5b, 5c, and 5d, a longitudinal acceleration sensor 4, a lateral acceleration sensor 3, a tire model setting part TM, a real yaw rate variation calculating part ΔYRR, a wheel load calculating part FZmn, a tire slip angle calculating part αmn, a calculating part μ of a road surface friction coefficient, a tire lateral force calculating part CFmn, and a calculating part CFKx of correction coefficient of moment of front and rear wheels. An estimated yaw rate is determined based on a yaw rate correction coefficient and a tire lateral force. Thus, the tire lateral force including the road surface friction coefficient, a tire slip ratio, and the tire slip angle is determined in response to them, thereby determining the estimated yaw rate as a value matching with vehicle motion.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body yaw rate
It is related to a fixing device. [0002] Conventionally, yaw rate has been used in automobiles and the like.
(Yawing speed)
Or cornering force (tire lateral force) and front and rear
It is known what you want from power. [0003] The difference between the right and left wheel speeds is determined.
The tread and conversion coefficient to the difference between the left and right wheel speeds of the driven wheels.
Multiply the arc speed to obtain the result, and calculate the result as yaw rate.
It was done. Also, the cornering force and the front of the vehicle
If you have a need for power,
Moment generated by the difference between the front and rear wheels of the
From the sum of the moment generated by
Things. [0004] However, the above-mentioned problems
The yaw rate calculated from the difference between the left and right wheel speeds.
When running, the wheel speed detection value is uncertain.
Cannot be used for control.
You. Also, the cornering force and the longitudinal force
For cornering force and vehicle body
Characteristics of tire model and mounted tire for estimating rear force
Due to differences in gender, the accuracy of yaw rate (estimated value) decreases
Problem. In this loss of accuracy,
Accelerometer zero point or gain deviation, or outside the vehicle
Disturbances from the road surface and vehicle body
Error due to lip angle error, road surface friction coefficient estimation error, etc.
The accuracy of the "knowledge force"
Something like that. SUMMARY OF THE INVENTION [0005] To solve such a problem.
To improve the accuracy of estimating the yaw rate
Therefore, in the present invention, the steering angle detection for detecting the steering angle is performed.
Sensor (1) and a wheel speed sensor (5a ·
5b, 5c, 5d) and before and after detecting the vehicle longitudinal acceleration
Acceleration sensor (4) and lateral acceleration for detecting vehicle lateral acceleration
Degree sensor (3) and yaw rate sensor for detecting yaw rate
(2) and a tire model with a tire dynamic model
Dell setting unit (TM) and actual yaw based on the yaw rate
Actual yaw rate change amount calculating section (ΔY
RR), the steering angle, the vehicle longitudinal acceleration, and the vehicle body
Tire for calculating tire slip angle based on lateral acceleration
A slip angle calculator (αmn), the steering angle and the wheel speed
Tire slip that determines the tire slip rate based on
Rate calculation unit (SLPmn) and road surface for estimating road surface friction coefficient
Friction coefficient calculating unit (μ), the longitudinal acceleration of the vehicle, and the vehicle
Wheel load based on body lateral acceleration and the tire dynamic model
A wheel load calculation unit (FZmn) for determining the weight,
Tip angle, the tire slip rate, the wheel load, and the road surface
Tire lateral force calculation to find tire lateral force based on friction coefficient
Outlet (CFmn), the actual yaw rate change amount and the tie
Yaw rate correction coefficient based on yaw force
A correction coefficient calculator (CFKx).
Estimated yaw rate based on the site correction coefficient and the tire lateral force
To be asked for. [0006] According to this, the detection by the yaw rate sensor is performed.
Yaw rate based on the issued yaw rate and tire lateral force
The correction coefficient is obtained, and the yaw rate correction coefficient and tire lateral force are calculated.
From the estimated yaw rate based on
Road surface friction coefficient, tire slip rate, tire slip
Horns are included and will be determined accordingly,
Influenced by the deviation of the zero point of the detected value of the yaw rate sensor
Estimated yaw ray as a value that matches the vehicle motion without
Can be asked. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG.
Embodiments of the present invention will be described in detail based on examples.
You. FIG. 1 shows a system of an automobile to which the present invention is applied.
FIG. As shown in the figure, the front wheels FR and F
The steering device for operating the steering of the L
In addition to the provision of the sa 1
Sensor 2, lateral acceleration sensor 3, longitudinal acceleration sensor 4,
Is provided. Front / rear tires FR / FL / RR / R
L is a wheel speed control for detecting the wheel speed of each tire.
Sensors 5a, 5b, 5c and 5d are provided respectively.
You. These sensors are controlled by the control unit 6 and the brake fluid pressure control.
It is connected to the actuator HU. The control device 6
HU (Hydraulic Unit) for controlling braking force
G) and the opening of the throttle valve of the engine.
DBW (Electronic Control Throttle) Controller for Degree Control
Control the injection amount and ignition timing supplied to the engine and the engine
The PGM-FI controller is connected and the HU
The braking force of each wheel is controlled to be distributed. What
A monitor 7 is connected to the control device 6, and the monitor 7 is connected to the monitor 7.
Monitor the normal or abnormal status of this equipment
Can be. FIG. 2 shows that the present invention by the control device 6 is suitable.
FIG. 4 is a block diagram showing an estimation logic of each control value used.
You. In the illustrated example, each of the above sensors 1, 2, 3,.
Using each detection value detected by 4.5a to 5d,
Row control, especially stability and steer-avi
Front-wheel drive control that balances steerability
Applicable to rear-wheel drive and 4-wheel drive vehicles as well as cars
In order to achieve this, each control value is determined.
In executing the above control, the slip of the four wheels is optimally controlled.
Need to be controlled using a four-wheel brake actuator
Mainly for slip control. [0010] In this case, it is necessary to mainly
As shown in FIG.
Lip angle αFR (αFL / αRR / αRL), tire lateral force (co
Nulling Force) CFFR (CFFL / CFRR / CFR)
L), the lateral acceleration LGE of the vehicle body,
Dynamic / driving force FXFR (FXFL / FXRR / FXRL).
Further, the longitudinal acceleration FGE of the vehicle body and the braking / driving force (ta)
It is good to use when calculating tire front-back force) and tire lateral force.
Find the road surface friction coefficient between the ear and the road surface. In each of the above sensors, the steering angle sensor 1
The steering angle STC is detected from each of the wheel speed sensors 5a-5
By d, the front wheel right wheel speed VWFR and the front wheel left wheel speed VWFL
・ Rear wheel right wheel speed VWRR ・ Rear wheel left wheel speed VWRL
And the yaw rate sensor 2 detects the yaw rate Y
AWR is detected, and the lateral acceleration sensor 3 accelerates the vehicle laterally.
The degree LG is detected, and the longitudinal acceleration sensor 4 detects the longitudinal direction of the vehicle.
An acceleration FG is detected. The steering angle STC is calculated by a tire actual steering angle calculating section S.
Input to TAn, and calculate the calculated values for each of the left and right front wheels.
The actual steering angle STAR / STAL of each tire is calculated as the tire slip angle
Input to the outlet αmn. In addition, each wheel speed VWFR / VWF
L / VWRR / VWRL is a tire slip ratio calculation unit S
Input to LPmn, yaw rate YAWR changes in actual yaw rate
The acceleration LG and FG are input to the
Input to the load calculation unit FZmn. In the wheel load calculation unit FZmn, in the illustrated example,
Is a tire model TM with a tire dynamic model
Each wheel load FZFR / FZFL based on acceleration LG / FG
・ Calculate FZRR and FZRL. From wheel load calculator FZmn
Each value output is based on the tire lateral force (corner for
S) Input to the calculation unit CFmn and the tire longitudinal force calculation unit FXmn
I do. The wheel load may be obtained by another method. The front-rear force calculation unit FXmn calculates the wheel load.
Each wheel load from the protruding portion FZmn and the slip ratio calculating portion S
Tire slip ratio SLPFR / SL for each wheel from LPmn
PFL / SLPRR / SLPRL and road surface friction coefficient calculation described later
Based on the road friction coefficient μ calculated at the protrusion μ,
Braking / driving force FXFR / FXFL / FXRR / FX of each wheel
RL is calculated. Exit from the tire longitudinal force calculation unit FXmn
Each value to be input is input to the estimated longitudinal acceleration calculation unit FGE,
The estimated longitudinal acceleration calculation unit FGE calculates the braking / driving force FXFR
Estimated longitudinal acceleration FG based on FXFL / FXRR / FXRL
Find E. The estimated longitudinal acceleration FGE is the estimated longitudinal acceleration
Filter processing is performed by the filter FGEF. That file
Estimated longitudinal acceleration filter value FGEF subjected to filter processing
Is input to the road surface friction coefficient calculating unit μ. The estimated longitudinal acceleration filter FGE
The output of F is also input to the estimated vehicle speed X direction calculation unit VVXβ.
Power. The estimated vehicle speed X direction calculation unit VVXβ
Estimated vehicle speed which is the longitudinal component (X direction) of the vehicle speed
Degree X direction value VVXβ is calculated, and the estimated vehicle speed X direction is calculated.
The value VVXβ is input to the contact point speed X direction calculation unit VCXmn.
You. In this contact point speed X direction calculation unit VCXmn,
Represents the estimated vehicle speed X direction value VVXβ,
Estimated yaw rate from estimated yaw rate calculation unit CFYAWR
Is input to the CFYAWR, and based on those values
Contact point speed X as estimated vehicle speed in the vehicle longitudinal direction of each wheel
Calculate direction value VCXFR, VCXFL, VCXRR, VCXRL
You. Note that the X-direction value of the contact point speed is calculated at the contact point of each wheel
It may correspond to the vehicle speed in the vehicle longitudinal direction. The estimated vehicle speed X direction value VVXβ
And estimated yaw rate CFYAWR are calculated in the Y-direction
Input to the output VCYmn. This contact point speed Y direction calculation unit
In VCYmn, the estimated vehicle speed X direction value VVXβ and
In addition to the estimated yaw rate CFYAWR,
The vehicle slip angle β is input from the slip angle calculation unit β,
Based on each value, the estimated
Contact point speed Y direction value VCYFR / VCYFL / VCYRR / V
CYRL is calculated. Contact point speed Y direction value in this case
Is the vehicle speed in the lateral (width) direction of the vehicle at the contact point of each wheel.
It may respond. Output from the contact point speed X direction calculation unit VCXmn
The calculated values are the tire slip angle calculation unit αmn and the wheel rotation direction speed.
It is input to the degree calculation unit VCmn. Also, the contact point speed Y direction
Each value output from the calculator VCYmn is also a tire slip angle.
It is input to the calculation unit αmn and the wheel rotation direction speed calculation unit VCmn.
In this example, the tire slip angle calculation unit αmn
The actual steering angle STAn, the X-direction value of the contact point speed, and the contact point speed
The tire slip angle αFR for each wheel based on the Y direction value
Calculate αFL ・ αRR ・ αRL, and each value is cornering
Force calculation unit FYmn and wheel rotation direction speed calculation unit VCmn
input. Note that the tire slip angle is determined by another method.
Is also good. In the wheel rotation direction speed calculation section VCmn, the tire speed is calculated.
Each tire slip angle from the lip angle calculation unit αmn and the above
Contact point speed X direction calculation unit VCXmn and contact point speed Y
A wheel for each wheel based on each value from the direction calculation unit VCYmn
Calculate the turning speeds VCFR, VCFL, VCRR, VCRL
You. Each value output from the rotation direction speed calculation unit VCmn
Is input to the slip ratio calculation unit SLPmn, and the slip ratio is calculated.
In the example shown in FIG.
Wheel speeds VWFR, VWFL, VWRR, VWR described
L, and the tire slip ratio SLPFR for each wheel
Calculate SLPFL, SLPRR, and SLPRL. In addition, Thailand
The slip rate may be obtained by another method. Further, the output from the tire slip angle calculation unit αmn is
Forced tire slip angle is calculated by cornering force
Input to the output FYmn. The cornering force calculation
In the section FYmn, the cornering force FYFR
FYFL / FYRR / FYRL are calculated based on each of the above tire slip angles.
It is calculated based on The cornering force calculator FY
Each cornering force output from mn is
It is input to the lateral force calculator CFmn. Each of the above-mentioned codes is included in the tire lateral force calculating section CFmn.
In addition to the nulling force, the slip rate calculator SLPmn
And each wheel load from the wheel load calculator FZmn
And the road friction coefficient μ from the road friction coefficient calculation unit μ
input. Based on them, the tire lateral force CFFR for each wheel
・ CFFL ・ CFRR ・ CFRL is calculated and tire lateral force is calculated
The output of the unit CFmn is input to the estimated lateral acceleration calculation unit LGE.
You. In the estimated lateral acceleration calculation unit LGE, the tire
Estimated lateral force based on each tire lateral force from lateral force calculation unit CFmn
The acceleration LGE is determined. The estimated lateral acceleration LGE is
Filtered by the constant lateral acceleration filter LGEF
You. The estimated lateral acceleration filter processing value LGEF is
Is output to the road surface friction coefficient calculating unit μ. In addition,
The lip force calculation unit TGM calculates the vehicle lateral acceleration LG and the vehicle front-back
Calculate total grip force TGM based on acceleration FG
The total grip force TGM and each acceleration sensor
The values LG and FG are input to the road friction coefficient calculation unit μ. The total grip force TGM is determined by the vehicle body
Route of sum of squares of lateral acceleration LG and longitudinal acceleration FG of vehicle body
(= (FG ² + LG ² ) ^1/2 ). Also, based on the yaw rate sensor value YAWR,
The actual yaw rate change is calculated by the actual yaw rate change calculation unit ΔYRR.
The actual yaw rate change amount ΔYRR is obtained.
RR output to front and rear wheel moment correction coefficient calculation unit CFKx
Is done. Front and rear wheel moment correction coefficient calculation unit CFKx
Is the tire lateral force calculation in addition to the actual yaw rate change amount ΔYRR.
The lateral force of each tire from the section CFmn is input.
Front and rear wheel models as yaw rate correction coefficients based on the
And the correction coefficients CFK1 and CFK2 are calculated. So
These front and rear wheel moment correction coefficients CFK1 and CFK2
Is output to the estimated yaw rate change amount calculation unit ΔYRE. In the estimated yaw rate change amount calculation section ΔYRE,
Is the front wheel / rear wheel moment correction coefficient CFK1 · CF
Each tire lateral force from the tire lateral force calculation unit CFmn in addition to K2
Has been entered and the estimated yaw rate based on those values
The change amount ΔYRE is calculated. Its estimated yaw rate change
The amount ΔYRE is output to the estimated yaw rate calculator CFYAWR
Is done. In the estimated yaw rate calculation unit CFYAWR,
Estimated yaw based on the estimated yaw rate change amount ΔYRE
A late CFYAWR is calculated. Its estimated yaw rate
CFYAWR is the above-mentioned contact point speed X direction calculation unit VC
Xmn and the contact point speed are output to the Y direction calculation unit VCYmn,
It is also output to the vehicle body slip angle change amount calculation section Δβ. The estimated vehicle speed is calculated by an estimated vehicle speed calculator VVβ.
Based on the degree X direction value VVXβ and the vehicle body slip angle β.
The constant vehicle speed VVβ is determined. The estimated vehicle speed VV
β, the estimated yaw rate CFYAWR, and the estimated lateral acceleration
The filter processing value LGEF and the vehicle body slip angle change amount calculation unit
Input to Δβ. The vehicle slip angle is calculated based on these values.
The change amount calculating section Δβ calculates the vehicle body slip angle change amount Δβ.
Based on the vehicle body slip angle change Δβ.
The vehicle body slip angle β is determined by the slip angle calculation unit β. What
Note that the vehicle body slip angle may be obtained by another method. In the control device thus configured,
The control procedure of the present invention will be described below with reference to the flowchart of FIG.
Show. First, in the first step ST1, the tire actual steering
The steering angle STC by the steering angle sensor is read by the angle calculation unit STAn.
For example, the gear ratio of the steering gear box
From each design value, the actual steering angle of each front wheel STAR / STAL
Ask for. In the next second step ST2, the yaw rate
Read the yaw rate YAWR by the sensor YAWR,
In the third step ST3, the acceleration sensors LG and FG are
The vehicle lateral acceleration LG and vehicle longitudinal acceleration FG
Then, the process proceeds to the fourth step ST4. In a fourth step ST4, the estimated vehicle speed X
The estimated vehicle speed X direction value VVXβ is calculated by a direction calculation unit VVXβ.
Is calculated. Calculation of this estimated vehicle speed X direction value VVXβ
Is shown in the sub-flowchart shown in FIG.
It may be performed in such a manner. In FIG. 5, in step ST4a, the vehicle body
Absolute value of slip angle (side slip angle) β is more than threshold value βc
It is determined whether or not. Absolute value of body slip angle β is threshold
If it is equal to or greater than the value βc, the process proceeds to step ST4b, where
The vehicle speed change amount VVBG in the vehicle body traveling direction is calculated by the following equation.
Calculated. VVBG = (FGEFcosβ + LGEFsinβ) × KX (1) where KX is a predetermined coefficient based on the vehicle design value. In the next step ST4c, the vehicle body longitudinal direction
Is calculated by the following formula. VVXBG = VVBGcosβ (2) Further, in step ST4a, the vehicle body slip is detected.
If the absolute value of the step angle β is smaller than the threshold βc
Proceeds to ST4d, where the vehicle speed conversion value of the estimated longitudinal acceleration is
It is calculated by the following equation. Vehicle speed conversion value = FGEF × KX (3) Then, step ST4c or step
In step ST4e, which proceeds after ST4d, step S4e is executed.
After passing T4c, the estimated vehicle speed X direction value VVXβ is
Calculated by the following equation: VVXβ (n) = VVXβ (n−1) + VVXBG (n) (4).
The body velocity X direction value VVXβ is calculated by the following equation: VVXβ (n) = VVXβ (n-1) + FGEF × KX (5) Here, (n) shows the current calculation loop.
(N-1) indicates the previous calculation loop. Thus, in the fourth step ST4,
ST4a to ST4e of the subroutine
The estimated vehicle speed X direction value VVXβ is calculated by
Estimated vehicle speed in the estimated vehicle speed X direction calculation unit VVXβ in
Seeking body speed. As shown in FIG. 2, the estimated vehicle speed is calculated.
In the section VVβ, the estimated vehicle speed X direction value VVXβ and the vehicle body slip
Is input. The above subflow (No. 4a
Steps ST4a to 4e shown in step ST4e)
Thus, the estimated vehicle speed X direction value VVXβ is obtained. did
Therefore, when estimating the vehicle speed, the road surface friction coefficient μ,
Body slip angle β, tire slip rate SLPmn, braking
Driving force FXmn, estimated longitudinal acceleration FGE (FGEF),
Each of the ear lateral force CFmn and the estimated lateral acceleration LGE (LGEF)
Values are used, and the vehicle's motion state includes road conditions.
Vehicle model in the form of
Or the effect of using only the longitudinal acceleration sensor.
Noise from the road surface or offset when climbing
The vehicle speed can be eliminated and an accurate estimated vehicle speed can be obtained.
You. As a result, the vehicle slips particularly on turning wheels.
Can determine the exact vehicle speed when
And improve the accuracy of travel control using vehicle speed.
You. In this way, the estimated vehicle speed X direction value VVXβ is calculated.
If issued, proceed to the fifth step ST5. In the fifth step ST5, the reference of each tire
The rotation speed VCFR, VCFL, VCRR, VCRL
calculate. At this time, first, the contact point speed X direction calculation unit VC
Xmn, the estimated vehicle speed X direction value VVXβ as described above
To the estimated yaw rate CFYAWR
You can know the behavior of each wheel. This allows each wheel
Contact point speed X direction value VCXFR / VCXFL / VCXRR / V
Calculate CXRL. Similarly, the contact point speed Y direction calculation unit V
CYmn, the estimated vehicle speed X direction value VVXβ and the estimated yaw rate
And the vehicle slip angle β
, The contact point velocity Y direction value VC for each wheel
Find YFR, VCYFL, VCYRR, VCYRL. But
Therefore, when the vehicle body slip angle β is 0, the contact point speed Y direction value
Becomes 0. Note that the above-mentioned contact point speed X direction value and contact point speed
The degree Y direction value is the X direction component with respect to the tire rolling direction.
Since it becomes the Y-direction component, the contact point speed X-direction calculation unit
VCXmn and the contact point speed Y direction calculation unit VCYmn
A Y-direction wheel speed estimation calculation unit is configured. And the ground point
Speed X direction value VCXmn (when expressed as a value, m is F
Or, R is entered, and n or R is entered. Less than
As well. ) And the contact point speed Y direction value VCYmn,
The wheel rotation direction speed calculation unit VCmn calculates the wheel rotation direction speed V for each wheel.
Find CFR, VCFL, VCRR, and VCRL. In the next sixth step ST6, the touch of each wheel
The ear slip ratio SLPmn is determined. Calculation of this slip ratio
When exiting, the speed based on the rotational speed VCmn is used as a reference.
And the case based on the wheel speed VWmn.
May be. When the rotational speed VCmn is used as a reference,
Is obtained by SLPmn = 100 × (VCmn−VWmn) / VCmn (6). When the wheel speed VWmn is used as a reference, SLPmn = 100 × (VCmn−VWmn) / VWmn (7) In the next seventh step ST7, the tire slip
The tip angle (tire slip angle) αmn is the X-direction value of the contact point speed.
VCXmn and the ground contact point speed Y direction value VCYmn.
Therefore, the process proceeds to the eighth step ST8 shown in FIG. In the eighth step ST8, the braking / driving force
(Tire front-rear force) FXmn, as described above,
Wheel load FZmn input to the force calculation unit FXmn and tire slip
Calculated based on the slip ratio SLPmn and the estimated road friction coefficient μ
I do. It should be noted that FIG.
The estimated road friction coefficient μ is divided into three levels: high, medium and low.
The tire longitudinal force for each tire slip rate
Uses a table (map) for calculating (braking / driving force) coefficients
Good to be. In this case, the coefficient obtained from FIG.
The braking / driving force FXmn can be obtained by multiplying the weight
You. The estimated road surface friction coefficient μ as shown in FIG.
By using a 3D map according to the difference
Accuracy can be improved. Note that when creating a map,
As shown in the example, three or more steps (high μ, medium μ, low μ)
Desirably on top. In the next ninth step ST9, the eighth step ST9 is executed.
From the braking / driving force FXmn calculated in step ST8.
Find the speed FGE. This calculation formula is the following formula.
No. FGE = (FXFR + FXFL + FXRR + FXRL) / (gross vehicle weight) (8) In the next tenth step ST10, the estimated longitudinal acceleration FG
E is filtered by the estimated longitudinal acceleration filter FGEF.
Manage. In this case, the estimated longitudinal acceleration FGE
The noise may be removed by a filter. In the next eleventh step ST11, the sixth step ST11 is executed.
Tire slip ratio SLP for each wheel determined in step ST6
mn, wheel load FZmn and cornering force FYmn
Calculate tire lateral force CFmn based on road friction coefficient μ
You. In this case, FIG.
As shown, the estimated road surface friction coefficient μ has three levels, high, medium and low.
Separately for each tire slip (side slip) angle
Using a table (map) for determining the tire lateral force coefficient
You. Then, by multiplying the coefficient obtained from FIG. 8 by the wheel load,
The tire lateral force CFmn when the slip ratio is 0 is obtained. Further, a table (map) shown in FIG.
The tire lateral force coefficient is determined by using (p). FIG.
Estimated road friction coefficient μ in three stages of high, medium and low as in 7.8
Divide the tire width for each tire slip rate
This is to determine the force reduction coefficient. From this 3D map
Obtain the obtained lateral force reduction coefficient according to the tire slip rate,
The tire power is multiplied by the tire lateral force CFmn obtained by setting the slip ratio to 0.
To obtain a highly accurate tire lateral force CFmn. In the next twelfth step ST12, the tire
Estimated lateral load based on each tire lateral force from lateral force calculation unit CFmn
The estimated lateral acceleration LGE is calculated by the following equation using the speed calculation unit LGE.
calculate. LGE = (CFFR + CFFL + CFRR + CFRL) / (gross vehicle weight) (9) Here, the eleventh step ST11 and the eleventh step ST11 are executed.
Estimated yaw rate CFY between step 12 and ST12
AWR should be obtained. The estimated yaw rate calculation subflag
The flowchart is shown in FIG. In the 21st step ST21 of FIG.
Calculate the moment MOMFX generated by the ear longitudinal force
You. The calculation formula may be the following formula. MOMFX = (FXFR−FXFL) × TRDF + (FXRR−FXRL) × TRDR (10) where TRDF and TRDR are front wheel tread and rear wheel tread.
Red (see FIG. 3). In the next 22nd step ST22, the front and rear wheels
In the moment (yaw rate correction coefficient) calculation unit CFKx,
Using the MOMFX of equation (10), the front wheel
The CPU correction coefficient CFK1 is obtained. CFK1 = [LSR × (CFFR + CFFL + CFRR + CFRL) + (ΔYRR / KD YR) + MOMFX] / (LSF + LSR) / (CFFR + CFFL) (11) LSF is the length from the center of gravity of the vehicle to the front wheel axis.
LSR is the distance from the center of gravity of the vehicle to the rear wheel axle.
(See FIG. 3), KDYR is the actual yaw rate change amount ΔYRR
Is converted into a moment. In the next 23rd step ST23, the above
Similarly, the rear wheel moment correction coefficient CFK2 is calculated by the following equation.
Ask for. CFK2 = [LSF × (CFFR + CFFL + CFRR + CFRL) + (ΔYRR / KD YR) + MOMFX] / (LSF + LSR) / (CFRR + CFRL) (12) In the next 24th step ST24,
Using CFK1 and CFK2 obtained in step, estimate
-Estimated yaw rate change amount by rate change amount calculation unit ΔYRE
(Estimated yaw moment) ΔYRE is obtained by the following equation. ΔYRE = (LSF × CFK1 × (FFR + CFFL) −LSR × CFK2 × (CFRR + CFRL) −MOMFX) × KDYR (13) This estimated yaw rate change amount (estimated yaw moment) ΔY
When integrating RE, the estimated yaw rate (body estimated yaw in
Speed). In the twenty-fifth step ST25, the estimated yaw
The calculation unit CFYAWR estimates the current routine.
The constant yaw rate CFYAWR (n) is obtained by the following equation. CFYAWR (n) = CFYAWR (n−1) + ΔYRE (n) × Tr (14) where CFYAWR (n−1) is the value of the previous subroutine.
The estimated yaw rate is obtained, and Tr performs this operation.
Loop time. Thus, the estimated yaw rate CFYA
By determining the WR, it is possible to achieve a stable driving control especially when turning.
The accuracy of the yaw rate used for control can be increased. For example, from the difference between the left and right wheel speeds,
In the case of finding the speed (yawing speed), braking
Sometimes trying to control the yaw moment
Since the value jumps, use that value for yaw moment control.
Could not be used. Also, tire lateral force
For those seeking yaw rate from power, those Thailand
Tire dynamics model for estimating tire lateral force and longitudinal force
Differences in characteristics from tires or out of the road outside the vehicle
Turbulence, and the body slip angle, which is indispensable for vehicle motion control.
Error, estimation error of road surface friction coefficient, etc.
The estimation accuracy of was reduced. As a result, the estimated yaw
In some cases, the accuracy of the data may be reduced. On the other hand, the yaw rate sensor YAWR
Just use the yaw rate YAWR detected by
Tire slip rate SLPmn and tire slip angle αmn
And the road friction coefficient μ, and the corresponding tire force
Calculate the tire front-rear force FXmn from the physical model and calculate the tire lateral force.
For example, FYmn, tire front-rear force FXmn, and yaw rate YAWR
The yaw rate correction coefficient (CFK1 · CFK2) is obtained from
Then, the tire lateral force FYmn, the tire longitudinal force FXmn, and the yaw
Calculated based on the late correction coefficient (CFK1 / CFK2)
Estimated yaw using the estimated yaw moment ΔYRE
I want CFYAWR. This gives the estimated yaw
Late CFYAWR is calculated as a value that matches the vehicle motion
The accuracy of the conventional estimated yaw rate
Can be solved. In addition, tires with different specifications and out of the road surface
Due to disturbances, errors occur in the estimation of tire lateral force FYmn
Also calculates the yaw rate correction coefficient (CFK1 / CFK2)
By using it, tire lateral force FYmn and lateral acceleration LGE
Error can be eliminated and the tire dynamics model
Adaptability can be improved. The vehicle body slip angle (side slip angle) β
The vehicle acceleration is determined by the lateral acceleration, the vehicle speed, and the yaw rate.
Calculate the slip angle change amount and calculate the vehicle body slip angle change amount.
By integrating, the body slip angle can be determined.
You. However, such prior art devices do not
-When the zero point of the late sensor is offset
Is the vehicle slip angle (body lateral acceleration / body speed-yaw
Rate), so it is always off at the vehicle slip angle
Since the set amount is included, the exact body slip angle is calculated.
I can't do it. On the other hand, the yaw rate sensor YAWR
Instead of using the detected value of
(LGEF), body speed VVβ and estimated yaw rate CFY
The vehicle body slip angle change amount Δβ is obtained based on the AWR and
Changes in the vehicle body slip angle β (n-1)
The vehicle body slip angle β is obtained by adding the amount Δβ. this
Causes the yaw rate sensor to have a zero-point offset.
The vehicle body slip angle β
Accuracy can be improved. In the above-described main control, the road surface
The coefficient of force in the longitudinal direction of the vehicle according to the friction coefficient μ
A map for calculating the directional force coefficient and the body lateral force reduction coefficient
Use multiple (three high, medium and low in the example shown)
You. This allows tire models to respond to differences in road friction coefficient.
Will be prepared in the same way, using each tire model
Cornering force and longitudinal force (tire lateral force,
Tire front-rear force).
To reflect road surface changes (especially road surface friction coefficient)
More accurate body with less errors
The slip angle β can be obtained. The estimated yaw rate CFYAWR is
Because it can be used as a late,
The estimated yaw rate C is used for the yaw rate used for the traveling control.
It is good to use FYAWR. In the next thirteenth step ST13, the road surface
An estimated road surface friction coefficient μ is obtained as a friction coefficient. This estimated path
The surface friction coefficient μ is the estimated lateral acceleration filter processing value LGEF
And the estimated longitudinal acceleration filter processing value FGEF,
It can be obtained based on the lug grip force TG. This suggestion
In calculating the constant road friction coefficient μ, the sub road shown in FIG.
It is performed as shown in the flowchart.
good. In FIG. 11, step ST13a
Now, the estimated road friction coefficient μ is converted to tire grip force
Determine whether it is smaller than the value. Its tire grip
The converted value is based on the total grip force TGM.
It can be expressed as a value (TGM / TIRGRP). Where TI
RGRP is the total grip force TGM is the road surface friction coefficient
It is a conversion value for adjusting to the dimension of. The estimated road surface
The initial value of the friction coefficient μ is 1, which corresponds to the dry road,
No. In step ST13a, the current estimated road surface friction
When the coefficient μ is greater than or equal to the tire grip force conversion value
Is to start the process of obtaining the estimated road friction coefficient μ.
It proceeds to step ST13b. In step ST13b,
The wheel slip angle αRR / αRL is the threshold value MUSLP
It is determined whether it is greater than or equal to. Where the absolute value
The reason for this is that one of the left and right
That's because. When the rear wheel has a large tire slip angle
Is to estimate the coefficient of road friction in the lateral direction.
(Less than or equal to the threshold), estimate the road surface friction coefficient in the front-rear direction.
The process proceeds to step ST13c to perform the setting. In the next steps ST13c to ST13e
Is an estimation condition for estimating the road surface friction coefficient in the longitudinal direction.
Conditions include vehicle speed, tire slip rate, and steering angle.
It is determined whether or not all conditions are satisfied. Therefore, in step ST13c, the estimated vehicle
Whether body velocity X direction value VVXβ is equal to or greater than threshold value VVFBGT
It is determined whether or not the value is equal to or larger than the threshold value.
Proceeds to 3d, and if less than the threshold, this subflow processing
This routine ends. In step ST13d
Means that at least one tire has a tire slip rate SLPmn
Is determined to be equal to or greater than the threshold value SLPBT,
If not, the process proceeds to step ST13e, and if it is less than the threshold,
Ends the current routine of this subflow process. S
In step ST13e, the steering angle STC is set to the threshold value BTS
It is determined whether or not the value is equal to or greater than TC.
Proceed to step ST13f, and if the
This routine of the flow processing ends. In step ST13f, the estimated longitudinal acceleration
Whether FGE is equal to or greater than the vehicle body longitudinal acceleration FG detected by the sensor
Is determined, and if the vehicle body longitudinal acceleration FG or more, it is estimated
In order to perform a process of reducing the road surface friction coefficient μ, FIG.
Proceeds to step ST13g shown in FIG.
If it is less than FG, the process of increasing the estimated road friction coefficient μ
Process. Thus, the road surface friction coefficient
Can be obtained, but may be obtained by another method. As shown in FIG. 12, step ST1
At 3g, the vehicle is detected by the sensor based on the estimated longitudinal acceleration FGE.
The difference obtained by subtracting the longitudinal acceleration FG exceeds the threshold value BTFG
And if it exceeds the threshold,
Proceed to step ST13h. In step ST13h,
The state exceeding the threshold determined in step ST13g
Determines whether or not it has continued for a certain period of time
Jump (a large change in the road surface friction coefficient)
Assuming, proceed to step ST13i, not μ jump
In this case, the process proceeds to step ST13j. Then, in step ST13j, the current
A constant value (for example, 0.0078) is calculated from the constant road friction coefficient μ.
By subtracting, the estimated road friction coefficient μ is reduced, and step S
Proceed to T13k. In step ST13k, the estimated road surface friction
Prevents friction coefficient μ from becoming unsuitable for control
Therefore, the upper and lower limits must be set so that they fall within a certain range.
Mitter processing is performed, and this subroutine processing is performed this time.
End In step ST13i, the step
The number of times determined to be a μ jump in ST13h is the specified number of times.
It is determined whether or not the number has reached
Proceed to step ST13j, and if the specified number of times has been reached, step
Proceed to ST131. In step ST131, the estimation
The tire friction force conversion value (TGM / T
IRGRP) and proceeds to step ST13k. What
In the above step ST13g, is the estimated longitudinal acceleration FGE
Difference between the vehicle longitudinal acceleration FG and the threshold value BTFG
If it is determined to be below, the process proceeds to step ST13k.
No. In step ST13a, the current estimation is performed.
Constant road friction coefficient μ is smaller than tire grip force conversion value
If it is determined that this is the case, the process proceeds to step ST13m. Stay
In step ST13m, the estimated road surface friction coefficient μ is
As a force conversion value (TGM / TIRGRP)
Proceed to ST13k. Further, before and after the estimation in step ST13f,
If the acceleration FGE is greater than the longitudinal acceleration FG of the vehicle
If it is determined that there is, step ST13n in FIG.
Proceed to. In step ST13n, the front of the vehicle
The difference is calculated by subtracting the estimated longitudinal acceleration FGE from the rear acceleration FG.
It is determined whether or not the threshold value BTFG has been exceeded.
In the following cases, the process proceeds to step ST13k, where the threshold value is
If it exceeds, the process proceeds to step ST13o. Step
In step ST13o, the current estimated road surface friction coefficient μ is set to a fixed value.
(For example, 0.0078) to add the estimated road surface friction coefficient
is lifted, and the process proceeds to step ST13k. Next, at step ST13b, the rear tires
It is determined that the slip angle is large, and the road surface friction
When estimating the number, step ST13p in FIG.
Proceed to. In this step ST13p, the actual yaw momen
It is determined whether or not the threshold has exceeded the threshold. This judgment
Although not shown in FIG. 2, for example, the yaw rate sensor 2
Of road surface friction coefficient using yaw rate YAWR detection value
Section μ, and the road surface friction coefficient calculation section μ
No. If the actual yaw moment is below the threshold,
This routine of the flow processing ends. In this step ST13p, actual yaw momen
If it is determined that the threshold has exceeded the threshold,
The process proceeds to step ST13q. In step ST13q, the estimated horizontal
The acceleration LGE (LGEF) is the lateral acceleration of the vehicle detected by the sensor.
LG is determined to be equal to or greater than the vehicle lateral acceleration LG.
In the case of, processing to reduce the estimated road surface friction coefficient μ is performed
Therefore, the process proceeds to step ST13r, and the vehicle body lateral acceleration LG
If the value is less than
Proceed to the steps to be performed. At step ST13r, the estimated lateral acceleration L
From the GE (LGEF), the vehicle body lateral acceleration LG
Determine whether the subtracted difference exceeds the threshold value BTLG
If the threshold is exceeded, step ST13s
Proceed to. At step ST13s, at step ST1
The state exceeding the threshold determined in 3r is longer than a certain time
It is determined whether it has continued or not.
Proceed to step ST13t assuming that it is a jump
If not, the process proceeds to step ST13u. Then, in step ST13u, the current
A constant value (for example, 0.0078) is calculated from the constant road friction coefficient μ.
By subtracting, the estimated road friction coefficient μ is reduced, and step S
Proceed to T13v. In step ST13v, the estimated road surface
Prevents friction coefficient μ from becoming unsuitable for control
Therefore, the upper and lower limits must be set so that they fall within a certain range.
Mitter processing is performed, and this subroutine processing is performed this time.
End In step ST13t, the step
The number of times determined to be a μ jump in ST13s is the specified number of times
It is determined whether or not the number has reached
Proceed to step ST13u, and if the specified number of times has been reached, step
Proceed to ST13w. In that step ST13w,
The tire friction force conversion value (TGM / T
IRGRP) and proceeds to step ST13v. What
From the estimated lateral acceleration LGE in step ST13r,
When the difference obtained by subtracting the vehicle body lateral acceleration LG is less than or equal to the threshold value BTLG
If it is determined that there is, the process proceeds to step ST13v. In step ST13q, the estimated horizontal
The speed LGE (LGEF) is the vehicle lateral acceleration L detected by the sensor.
If it is determined that the value is equal to or larger than G, step ST13x
Proceed to. In step ST13x, the side of the vehicle
Subtract estimated lateral acceleration LGE (LGEF) from acceleration LG
Determine whether the difference exceeds the threshold value BTLG,
If it is equal to or smaller than the threshold, the process proceeds to step ST13v, and
If the threshold is exceeded, proceed to step ST13y.
No. In step ST13y, the current estimated road surface friction coefficient
A constant value (for example, 0.0078) is added to μ to obtain an estimated path.
The surface friction coefficient μ is raised, and the process proceeds to step ST13v. Thus, the estimated road surface friction coefficient μ is obtained.
Therefore, it is possible to improve the estimation accuracy of the road surface friction coefficient.
Wear. Relying solely on the tire slip ratio SLPmn with conventional technology
If the tire slip rate is small on snowy or frozen roads
Problem that the road surface friction coefficient is estimated high
However, according to the logic for obtaining the estimated road friction coefficient μ,
If such a problem does not occur. That is, the vehicle longitudinal acceleration and the vehicle lateral acceleration
Using the degrees, it is possible to perform estimation according to
And by judging μ jump,
Prevents constant road friction coefficient μ from becoming a large value.
And always estimate a value that matches or is close to the actual road friction coefficient.
can do. In addition, tire slip angle αmn
Tire data to determine tire lateral force and tire longitudinal force
From front to back, lateral acceleration and yaw
As well as their estimates and
Correction of estimated road friction coefficient μ from comparison with each sensor detection value
(The process of lowering or raising μ
Management). Also, based on the corrected estimated road friction coefficient μ,
To adjust the tire data map gain.
(In the example shown, it is adapted to high, medium and low μ). In this way, during acceleration / deceleration, turning, etc.
Highly accurate road surface friction coefficient
Can be estimated. The estimated road surface friction coefficient μ
The target accuracy is the target accuracy of the tire slip angle αmn of 0.5 degrees.
Then, it can be set to 0.05. In the next fourteenth step ST14, the vehicle body
The lip angle change (side slip angle rate) Δβ is calculated by the following formula.
It is determined by the body slip angle change amount calculation section Δβ. Δβ = KLGVXD × (LGE / VVβ) −CFYAWR (15) where KLGVXD is the estimated lateral acceleration LGE (LGE
F) and the estimated vehicle speed VVβ
This is a coefficient for matching the dimension with the size CFYAWR.
The product of this vehicle body slip angle change amount (side slip angle rate) Δβ
When it is divided, it becomes the vehicle body slip angle (side slip angle). Then, in the fifteenth step ST15, the vehicle
The body slip angle (side slip angle) β is calculated using the following equation.
It is obtained by the lip angle calculation unit β. β (n) = β (n−1) + Δβ (n) (16) where n is a value calculated in the current routine, and n−1 is a value calculated in the previous routine.
The calculated value of the routine is shown. That is, the vehicle slip angle β
In the calculation, the vehicle body slip angle β (n
-1) is obtained in the fourteenth step ST14 of this routine.
It is obtained by adding the vehicle body slip angle change amount Δβ. To determine the vehicle body slip angle β,
As described above, the difference in the estimated road friction coefficient μ (in the illustrated example,
Consider the tire longitudinal force and tire lateral force according to (high, middle, low)
You can use the tire model
Of tire lateral force and tire longitudinal force (braking / driving force)
Estimated value errors can be reduced, and more accurate
The vehicle body slip angle β can be obtained. The control device configured as described above
Stability and steerability (s
teerability) can be controlled.
One example is oversteer / understeer control.
The control is shown below. Conventionally, each sensor value of steering angle and yaw rate
The control amount is calculated by
The moment in each case
Some are controlled by rake force. It is the steering angle
Norm and yaw rate sensor
The deviation from the output value is used as the control amount.
Adds braking force to the two outer wheels, and understeer
Applies braking force to the two inner wheels,
It controls the moment generated in the vehicle body according to the state.
You. However, in this yaw rate control,
By directly monitoring and controlling the grip state of each tire of the four wheels
Is not available, so moment control is possible,
You cannot control the trace. For example, the running trajectory turns
Swelling outward (drift out)
You. On the other hand, vehicle operation using this control device
In the dynamic control, the vehicle speed VVβ, the road surface friction coefficient μ,
Body slip angle β and tire slip angle αmn
At the time of oversteer, three
The wheels are controlled with the braking force corresponding to the vehicle body slip angle β,
-When steering, adjust both rear wheels according to the amount of understeer.
It can be controlled by the braking force. This makes Momen
Control the kinetic energy of the vehicle,
Thus, drift-out of the vehicle can be suppressed. At the time of this oversteer / understeer,
A specific example of the control is shown in the flowcharts of FIGS.
7 is shown below with reference to a control logic block diagram. Figure
As shown in the fourteenth 31st step ST31,
Instead, it is determined whether or not the momentum reduction control is being performed. This is
As noted, the system for oversteer / understeer
Do you want to control braking at least on both rear wheels?
To determine whether the braking control of both rear wheels is currently being performed.
It is. If it is under control, the
32. Go to step ST32, and if the control is being performed,
33rd step S for executing the flow of the reduction control end condition
Proceed to T33. In the thirty-second step ST32, the exercise amount is reduced.
To determine whether the control start condition is satisfied, the estimated vehicle speed VV
β is greater than or equal to a threshold value VVALST (for example, 20 km / h)
Is determined, and if it is equal to or greater than the threshold value VVALST,
The process proceeds to the 34th step ST34. The 34th step S
At T34, the front wheel and rear wheel
The rear wheel tire slip angle αRn
Determines whether the absolute value is greater than or equal to threshold value ALFIN
If the value is equal to or more than the threshold value ALFIN, the 35th step
Proceed to ST35. Thus, the start condition of the momentum reduction control is
The determination is made based on the vehicle speed and the tire slip angle of the rear wheels. Each
If the values are less than the threshold value in steps ST32 and ST33,
In this case, the current routine ends. In the 35th step ST35, the vehicle is decelerated.
A rear wheel basic target wheel speed VIRn required for control is calculated. This
The rear basic wheel speed VIRn of the rear wheel is as shown in FIG.
The reference yaw rate MYRN calculated from the steering angle STC
O and the target wheel speed change rate RU from the yaw rate YAWR
DVR is calculated and the estimated vehicle speed X direction value VVXβ
Calculate the wheel rotation direction speed VCmn from these and change those target wheel speeds.
Rate RUDVR and the rotational speed VCmn.
It is. The process proceeds to the 33rd step ST33.
In such a case, it is determined whether the vehicle speed condition is satisfied.
The lower limit vehicle speed (for example, 10 km /
h), and when the vehicle speed is lower than the lower limit vehicle speed, the termination condition
This routine is terminated when the condition is satisfied, and otherwise
It is determined that the condition is satisfied, and the process proceeds to the 36th step ST36. sand
In other words, the control does not start unless the user is in a certain state of motion.
Once they start, they don't stop immediately. No.
In step ST36, the vehicle body slip angle condition is satisfied.
Is determined by comparing with the lower limit vehicle body slip angle.
If it is equal to or larger than the vehicle body slip angle, a 37th step ST37
Proceed to. This is because the vehicle body slip angle is large during rear wheel control.
If it becomes too hard, the vehicle will continue
Is unstable (oversteer or spin)
If the vehicle body slip angle increases to a certain extent,
It is to complete. At the 37th step ST37, the tire slip is
Whether the slip angle condition is satisfied is determined by the lower limit tire slip angle.
(A value that can be judged to have returned to a stable state)
If it is not less than the lower limit tire slip angle, the 38th step S
Proceed to T38. In the 38th step ST38, the lateral acceleration
Whether the condition is satisfied or not is compared with the lower limit lateral acceleration,
If it is equal to or smaller than the lower limit lateral acceleration, go to the 39th step ST39.
If it is not less than the lower limit lateral acceleration, the momentum
In order to continue the reduction control, go to the above-mentioned 35th step ST35.
move on. Note that the vehicle body slip angle is determined in the 36th step ST36.
If the condition is satisfied, the tire is turned on in the 37th step ST37.
If the slip angle condition is satisfied,
Proceed to step ST39. Then, in the thirty-ninth step ST39,
Delay time as a good time to end the momentum reduction control
(For example, 200 ms) is completed, and
If the ray time has not expired, continue the momentum reduction control.
Proceed to the 35th step ST35 to execute
If so, this routine ends. When proceeding to the 35th step ST35
In the next 40th step ST40, understeer
Is determined (oversteer). In this judgment
The norm yaw rate MYRNO and yaw rate YAWR
(O / U). Soshi
In the case of understeer, the 41st step ST41
And in the case of oversteering, the 42nd step ST
Proceed to 42. In the forty-first step ST41, an unders
Target wheel speed change amount (target vehicle speed) calculated according to the amount of tare
The wheel speed change rate (RUDVR) is used as a reference target wheel speed (rotational direction speed).
From the control target wheel speed (vehicle momentum low).
Decrease control target vehicle speed) VIRn is obtained. Next step 43
In ST43 (see FIG. 15), the target control amount of the inner wheel is
In a forty-fourth step ST44, the target control amount of the outer wheel is
The corresponding rear wheel speed (VWRR / VWRL) and control target
Calculated from the deviation from the wheel speed VIRn (VERR / VER
L). In the next forty-fifth step ST45, the turning
Side limiter value (ILIN) and tire lateral force CFmn
Obtained based on the tire longitudinal force FXmn and the road surface friction coefficient μ
(Refer to FIG. 17).
To determine the limiter value (ILOUT) outside the turn. Also, as described above, oversteer is performed.
If the process proceeds to the 42nd step ST42,
The wheel control amount (target control amount) is calculated. First, the reference target car
Wheel speed (rotational direction speed VCmn) is controlled.
(Motor amount reduction control target vehicle speed) VIRn, and then the control target
Wheel speed VIRn and both rear wheel speed detection values VWRR / VWRL
From the target control amounts VERn of the left and right rear wheels, respectively.
Is calculated. In the next forty-seventh step ST47, the above a
As in the case of understeer, the limiter value (ILTO
T), and the process proceeds to a forty-eighth step ST48. Also on
From the 46th step ST46 to the 48th step ST4
Proceed to 8. In the forty-eighth step ST48, the forty-sixth step is performed.
Calculated in step ST46 or the 47th step ST47
The upper limit of the rear wheel control amount is regulated using the limiter value.
The rear wheel control amount (vehicle operation
(Moving amount reduction control amount) ITRn is obtained. From the next forty-ninth step ST49, the
Mohme calculated from body slip angle β in the case of burstair
Suppresses moment control when controlling using
Calculate the control amount. First, in a forty-ninth step ST49, the home
Control (β angle) control is determined. This is a body slide
It can be determined by the magnitude of the flip angle β. During moment control
If so, proceed to the 50th step ST50 to control the moment.
Start from the flow of the start condition.
Proceeding to a 51st step ST51, the moment control end condition is reached.
Execute the flow. When the process proceeds to the 50th step ST50,
Indicates whether the estimation process of the steering angle STC has been completed or not.
Is determined, and when the processing is completed, the process proceeds to step 52, ST52.
The routine proceeds, and if not completed, this routine is terminated.
In the 52nd step ST52, the estimated vehicle speed VVβ
Whether the threshold value is VVALST (for example, 20 km / h) or more
Is determined, and if it is equal to or greater than the threshold value VVALST, the
It proceeds to step ST53. The 53rd step ST53
Now, the satisfaction of the condition of the tire slip angle αRn
The absolute value of the lip angle αRn is greater than or equal to the threshold value ROTIN1.
And the tire slip angle change rate Dα (degree / s)
Value DROTIN or more, or tire slip angle α
If the absolute value of Rn is equal to the threshold value ROTIN2 (> ROT)
In the case of IN1), it is determined whether or not the condition is satisfied.
Goes to the 54th step ST54 (FIG. 16). In the fifty-fourth step ST54, the vehicle body slip is detected.
And the vehicle slip angle change amount Δβ is satisfied.
Is determined. Also in this case, the vehicle body slip angle β
Is greater than or equal to the threshold value β1, and the vehicle body slip angle change rate
When Dβ (degrees / s) is greater than or equal to threshold value Dβ,
The condition is satisfied when the lip angle β is the threshold value β2 (> β1).
Is determined, and if it is equal to or larger than the threshold value, the 55th step is performed.
The process proceeds to step ST55. The 50th step ST50 and the 52nd step
Steps ST52 to 54.
Judge whether the start control start condition is satisfied and
If not established in each step (NO), this routine
End Also, the process proceeds to the 51st step ST51.
In this case, the vehicle speed termination condition (for example, 10 km /
It is determined whether or not h) holds. Vehicle speed lower limit car
If the speed is less than or equal to the speed, the end condition is satisfied and this routine ends.
Otherwise, it is determined to be unsatisfied and the
Proceed to step ST56. In the 56th step ST56, the vehicle
Whether the signs of body slip angle and yaw rate are the same
Is determined, and if they are the same, a 57th step ST57
Proceed to. In the fifty-seventh step ST57, the tire slip is
Top angle condition (value that can be judged to have returned to a stable state) is satisfied
It is determined whether or not it is performed. If the tire slip angle condition is met
If it is standing, it proceeds to the 58th step ST58,
If the condition is satisfied, the process proceeds to the 55th step ST55. Ma
In the 56th step ST56, the vehicle body slip angle and
58th step even if the sign of the rate is different
Proceed to ST58. In the fifty-eighth step ST58, the vehicle body slip is detected.
Set a good time (for example, 200 ms) for ending the angle control.
Determines whether all delay times have expired
If the time is not over, continue the vehicle body slip angle control.
Proceed to the 55th step ST55 to execute
If so, this routine ends. When proceeding to a fifty-fifth step ST55,
Indicates that the vehicle body slip angle control condition is satisfied.
Therefore, the target vehicle body slip angle RO for performing the control is
TA is calculated based on the road friction coefficient μ as shown in FIG.
And calculate. In the next 59th step ST59, the target vehicle
From the deviation between body slip angle ROTA and body slip angle β
Moment control amount (VEβ · dVEβ · d ² VEβ)
calculate. Here, VEβ is the estimated vehicle body slip angle β.
Minus the target vehicle body slip angle β (ROTALM)
Yes, it is the deviation from the target vehicle body slip angle (limit angle),
dVEβ is the amount of change in the deviation (differential value,
If the body slip angle β is a fixed value, the yaw rate equivalent value)
Yes, d ² VEβ is the change amount of the change amount (the second order of the deviation).
If the target vehicle body slip angle β is a fixed value,
−equivalent change rate). Next 60th step S
At T60, based on the road friction coefficient μ and the wheel load FZmn,
Calculate the limit value of the control amount (ROTLH / ROTTLL)
Put out. Then, in the 61st step ST61, the moment
Control amount (VEβ · dVEβ · d ² VEβ) limiter
Value (ROTLH / ROTLL)
The side front wheel control amount ROTTOTTL is determined, and this routine ends.
Complete. Then, the rear wheel control amount ITRn and the turning outer front wheel
The target in the braking control according to the control amount ROTTOTTL
Set the hydraulic pressure Pmn. This target oil pressure Pmn is set for each wheel.
Set (PFR, PFL, PRR, PRL) and braked accordingly
Control the power. This allows for moment control
Along with reducing the kinetic energy of the vehicle, the vehicle drifts
Out can be suppressed. For example, as shown in FIG.
The neutral trajectory in the round running is indicated by the solid arrow N in the figure.
In case of understeer
Looks like the dashed arrow US in the figure and oversteer
In such a case, as indicated by the imaginary line arrow OS in the figure.
You. In the case of understeer US,
Determined as described above according to the moving condition and road surface conditions
Braking force on both rear wheels RR and RL with the target oil pressure PRR and PRL
Apply FXRR / FXRL. This makes the vehicle neutral
It can run on a simple turning locus. Obers
In the case of the tare OS, the target oil pressure PRR
Apply braking force FXRR / FXRL to both rear wheels RR / RL by PRL
The front wheel turning outside (right front wheel F in the illustrated example)
R) is applied with the braking force FXFR by the target oil pressure PFR. this
Allows the vehicle to travel on a neutral turning locus
be able to. In the illustrated example, the control based on the braking force is used.
Although shown above, control by driving force is also possible. That
In this case, the driving force can be distributed arbitrarily for each wheel.
What is necessary is just to provide a distribution device. As described above, according to the present invention, the yaw rate
Based on the yaw rate detected by the sensor and the tire lateral force
The yaw rate correction coefficient, and calculate the yaw rate correction factor.
Determining estimated yaw rate based on number and tire lateral force
From the tire lateral force, the road surface friction coefficient, tire slip rate,
Tire slip angles are included and determined accordingly
The estimated yaw rate as a value that matches the vehicle motion.
Site can be obtained with high accuracy. [0117] The difference in tire type and the
Even if there is an error in tire lateral force due to disturbance,
By using the yaw rate correction coefficient, the tire lateral force and
It is possible to eliminate errors when estimating the vehicle lateral acceleration.
In some cases, the adaptation effect of the tire dynamic model may be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram of an automobile to which the present invention is applied. FIG. 2 is a block diagram showing an estimation logic of each control value to which the present invention is applied. FIG. 3 is a diagram showing a tire slip angle, a tire lateral force, a lateral acceleration of a vehicle body, a tire longitudinal force, and a yawing in a vehicle at the time of turning. FIG. 4 is a flowchart showing a control procedure. FIG. 5 is a sub-flowchart for calculating an estimated vehicle speed. FIG. 6 is a flowchart following FIG. 4; FIG. 7 is a map for obtaining a tire longitudinal force coefficient. FIG. 8 is a map for obtaining a tire lateral force coefficient. FIG. 9 is a map for obtaining a tire lateral force reduction coefficient. FIG. 10 is a sub-flowchart for calculating an estimated yaw rate. FIG. 11 is a sub flowchart for estimating a road surface friction coefficient; FIG. 12 is a flowchart following FIG. 11; FIG. 13 is a flowchart following FIG. 11; FIG. 14 is a flowchart for calculating a vehicle motion control control amount. FIG. 15 is a flowchart following FIG. 14; FIG. 16 is a flowchart following FIG. 15; FIG. 17 is a block diagram showing an estimation logic of each control value in the vehicle motion control. . FIG. 18 is an explanatory diagram showing a control procedure at the time of understeer / oversteer. [Description of Signs] 1 steering angle sensor 2 yaw rate sensor 3 lateral acceleration sensor 4 longitudinal acceleration sensor 5a, 5b, 5c, 5d wheel speed sensor TM tire model setting unit ΔYRR actual yaw rate change amount calculation unit FZmn wheel load calculation unit αmn tire slip Angle calculator μ Road friction coefficient calculator CFmn Tire lateral force calculator CFKx Front and rear wheel moment correction coefficient calculator (yaw rate correction coefficient calculator)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) B62D 103: 00 B62D 111: 00 111: 00 113: 00 113: 00 137: 00 137: 00 G01P 15/00 J (72) Inventor Hiroyuki Urabe 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3D032 CC30 DA03 DA24 DA25 DA29 DA39 DA40 DA46 DA82 DC02 DC08 DC11 DC29 DC33 DC34 DD02 DD06 EA01 FF01 FF05 FF07 GG01 3D046 BB25 GG10 HH08 HH25 HH26 HH36

Claims (1)

Claims: 1. A steering angle sensor for detecting a steering angle, a wheel speed sensor for detecting a wheel speed, a longitudinal acceleration sensor for detecting a longitudinal acceleration of a vehicle body, and a lateral acceleration for detecting a lateral acceleration of the vehicle body. A sensor, a yaw rate sensor that detects a yaw rate, a tire model setting unit that sets a dynamic model of a tire, an actual yaw rate change amount calculating unit that obtains an actual yaw rate change amount based on the yaw rate, the steering angle and the vehicle body longitudinal acceleration. A tire slip angle calculator for calculating a tire slip angle based on the vehicle body lateral acceleration, a tire slip ratio calculator for calculating a tire slip ratio based on the steering angle and the wheel speed, and estimating a road surface friction coefficient. A road friction coefficient calculating unit, and calculating a wheel load based on the vehicle longitudinal acceleration, the vehicle lateral acceleration, and the tire dynamic model. A wheel load calculating unit, a tire lateral force calculating unit that determines a tire lateral force based on the tire slip angle, the tire slip ratio, the wheel load, and the road surface friction coefficient; and an actual yaw rate change amount and the tire. A vehicle body yaw rate estimating apparatus comprising: a yaw rate correction coefficient calculating unit that calculates a yaw rate correction coefficient based on a lateral force; and calculating an estimated yaw rate based on the yaw rate correction coefficient and the tire lateral force.