JP3269088B2 - Yaw rate estimation method - Google Patents

Abstract

PURPOSE:To estimate the yaw rate with high precision independently of the existence of the effective radius difference between the left and right wheels, in the estimation of the yaw rate from the revolution speed difference between the left and right wheels. CONSTITUTION:The yaw rate SVY obtained in the straight advance of a vehicle is considered as the yaw rate error caused by the effective radius difference between the left and right wheels, and accommodated as yaw rate correction value VYC in relation to the car body speed VSO. Further, in turn of the vehicle, the yaw rate correction value VYC corresponding to the car body speed VSO is read as the yaw rate correction value OVYC, (S410-S440), and the final yaw rate VY is obtained by subtracting the proper yaw rate correction value OVYC from the yaw rate SVY obtained at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed of right and left wheels of a vehicle.
The present invention relates to a method of estimating a yaw rate of a vehicle body using a degree difference , and more particularly to a technique of improving the accuracy of obtaining the yaw rate.

[0002]

BACKGROUND ART It may be necessary to obtain the yaw rate of a vehicle body. In this case, it is possible to directly acquire the yaw rate using a special sensor called a yaw rate sensor . Also, utilizing the fact that a difference in rotation speed between the left and right wheels occurs according to the yaw rate of the vehicle body, a method of indirectly obtaining the yaw rate using a rotation sensor that detects the rotation speed of the left and right wheels of the vehicle, i.e., yaw rate estimation There are also methods .

An example of this yaw rate estimation method is disclosed in Japanese Patent Application No. 3-39281 filed by the present applicant .
It is described in a detailed document (JP-A-4-257775) . In this specification, there is provided a vehicle control device that includes a brake on a front wheel that is a non-drive wheel and suppresses the occurrence of spin during turning acceleration of a vehicle whose rear wheel is a drive wheel,
There is described an apparatus including a spin detecting means for detecting occurrence of spin and a front wheel brake control means for operating a front wheel brake upon detecting spin. The spin detecting means obtains the yaw rate of the vehicle body using the above yaw rate estimation method, and determines whether the yaw rate has exceeded a threshold value or whether a differential value of the yaw rate has exceeded a threshold value. Then, it is determined that a spin has occurred.

[0004]

However, studies conducted by the present applicant have revealed that the conventional yaw rate acquisition methods have the following problems. Actually when the vehicle goes straight
Despite having a zero yaw rate,
May not be 0, in which case,
Error in the yaw rate obtained when turning the vehicle
If you cannot get the yaw rate with high accuracy
It turned out that there was a problem. In particular, the yo
-The rate estimation method has the following problems. Sand
Chi, the yaw rate estimation method, for the assumption that the effective radius coincide with each other between the left and right wheels, for example, and since the amount of wear of the tire is different between left and right wheels, is effective radius for the tire pressure is different If they do not match sufficiently, the absolute value of the estimated yaw rate obtained by the yaw rate estimation method does not become 0 even though the vehicle is traveling straight,
For example, as shown in the graph of FIG. 9, the larger the vehicle speed, and the larger the effective radius difference between the right and left wheels, the larger. Thus, this yaw rate estimation method includes:
If the effective radii do not sufficiently match, there is a problem that the yaw rate cannot be accurately estimated.

[0005] Based on this finding, the present invention is a method for obtaining a vehicle body yaw rate, considers the yaw rate obtained when the vehicle straight and yaw rate error, by correcting the yaw rate obtained when the vehicle turns in the yaw rate error, a yaw rate It has been made to acquire with high accuracy.

[0006]

Means for Solving the Problems To solve this problem, the invention according to claim 1 comprises the following steps: (a) obtaining the original yaw rate by using the rotational speed difference between the left and right wheels when the vehicle goes straight ahead, and correcting the original yaw rate by the yaw rate correction; As a value, a yaw rate correction value obtaining step of storing the yaw rate correction value in association with the vehicle speed at which it was obtained, and (b) obtaining the original yaw rate using the rotational speed difference between the left and right wheels at the time of turning the vehicle, and from the original yaw rate. Associated with the same vehicle speed as when it was obtained
A correction yaw rate obtaining step of obtaining a correction yaw rate by subtracting the yaw rate correction value stored in advance.
In the positive value acquisition step, the yaw rate correction value is determined in advance.
Out of multiple vehicle speed ranges
The vehicle speed range to which the vehicle speed at the time the
Acquired in association with the correction yaw rate acquisition process
The vehicle speed when the original yaw rate was acquired during the turn
Turn the yaw rate correction value corresponding to the vehicle speed range to which it belongs
Correction yaw rate by subtracting from the original yaw rate at the time
The site is acquired.

[0007]

The yaw rate error that occurs because the effective radius differs between the left and right wheels changes according to the vehicle speed. On the other hand, when the vehicle goes straight, the actual yaw rate is 0, so the original yaw rate acquired when the vehicle goes straight is equal to the yaw rate error under the vehicle speed at the time when the vehicle was acquired. It is also equal to the yaw rate error contained in the original yaw rate obtained below. Based on such knowledge, the yaw rate estimating method according to the first aspect of the present invention uses the yaw rate
The correction value is stored in association with the vehicle speed, and the yaw rate correction amount stored in association with the vehicle speed at the time of the acquisition is subtracted from the original yaw rate acquired at the time of turning the vehicle to obtain a yaw rate error from the original yaw rate. except for. Further, a yaw rate estimation method according to the invention of claim 2
The method stores the yaw rate correction value corresponding to the vehicle speed range.
The car at the time the original yaw rate was acquired during the turn
Yaw rate correction corresponding to the body speed range to which the body speed belongs
By subtracting the value from the original yaw rate when turning,
-Excluding late error.

Therefore, according to the present invention, an effect is obtained that the yaw rate can be accurately estimated regardless of whether the effective radius differs between the left and right wheels.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment in which the present invention is applied to a yaw rate estimating method in the vehicle control device will be described in detail with reference to the drawings.

In FIG. 2, reference numeral 10 denotes a brake pedal, and the same pressure is generated in two pressurizing chambers of the master cylinder 12 in response to the depression. The hydraulic pressure generated in one pressurizing chamber is transmitted to the two front wheel cylinders 16 and 18 via the main liquid passage 14, and the hydraulic pressure generated in the other pressurizing chamber is transmitted to the two rear wheel cylinders via the main liquid passage 20. The power is transmitted to the cylinders 22 and 24. The front wheel cylinders 16 and 18 operate the brakes of the left front wheel 26 and the right front wheel 28, respectively, and the rear wheel cylinders 22 and 24 operate the brakes of the left rear wheel 30 and the right rear wheel 32, respectively. The left and right front wheels 26, 28 are steering wheels and non-driving wheels, and the left and right rear wheels 30, 32 are non-steering wheels and driving wheels. A proportioning / bypass valve 34 is provided astride the main fluid passages 14 and 20. When the front wheel system is normal, the fluid pressure of the master cylinder 12 is reduced at a fixed ratio, and the rear wheel cylinders 22 and 24, and is transmitted without pressure reduction when the front wheel system fails.

In addition to the master cylinder 12, the brake device is provided with a hydraulic pressure source 40 for generating hydraulic pressure by power. The hydraulic pressure source 40 includes a pump 44 for pumping brake fluid from a reservoir 42, an accumulator 46 for storing the brake fluid under pressure, a pump motor 48 for driving the pump 44, a relief valve 50, a pressure switch 52, and the like.

The liquid pressure source 40 is connected to the main liquid passage 1 by the liquid passage 60.
The liquid passage 60 is provided with an electromagnetic hydraulic pressure control valve 62 and an electromagnetic opening / closing valve 64. An electromagnetic opening / closing valve 66 is provided at a portion on the master cylinder 12 side of the connection point between the main liquid passage 14 and the liquid passage 60. The electromagnetic on-off valve 64 is a normally closed valve, the electromagnetic on-off valve 66 is a normally open valve, and the master cylinder 12 is always in communication with the front wheel cylinders 16 and 18.
When the solenoids 4 and 66 are excited, the hydraulic pressure source 4
0 is communicated with the front wheel cylinders 16 and 18. The brake device 68 is configured as described above.

The above-mentioned pump motor 48, electromagnetic hydraulic pressure control valve 6
2. The electromagnetic switching valves 64 and 66 are connected to the output processing circuit 72 of the control device 70. The control device 70 includes a CPU 74,
The computer mainly includes a ROM 76, a RAM 78, and the like, and various sensors are connected to the computer via an input processing circuit 80. The pressure switch 52, a brake switch 82 for detecting depression of the brake pedal 10, a steering angle sensor 84 for detecting an operation angle of a steering wheel, front left and right wheels 26 and 28.
And rotation sensors 90, 92, 94, 96 for detecting the rotation speeds of the left and right rear wheels 30, 32, respectively. The control device 70 controls the electromagnetic hydraulic pressure control valve 62 and the like based on signals from the respective sensors to suppress the generation of spin. For this purpose, the ROM 76 stores a spin suppression program represented by the flowchart of FIG.

The operation of the vehicle control device will be described below with reference to the flowchart of FIG. When the ignition key of the vehicle is turned on, initial settings (not shown) are performed at the same time, and the electromagnetic hydraulic pressure control valve 62 and the electromagnetic on-off valve 6
4, 66 are in a non-excited state. If the brake pedal 10 is depressed in this state, the hydraulic pressure generated in the master cylinder 12 is supplied to the wheel cylinders 16, 18, 22, and 24 to brake the vehicle.

While the ignition key is in the ON state, the spin suppression program shown in the flowchart of FIG. First, in step S100 (hereinafter abbreviated as S100; the same applies to other steps), the left and right rear wheels 30,
The maximum wheel speed VW which is the larger of the 32 rotation speeds
RMX is calculated. Specifically, left and right rear wheels 30, 32
Are read, and it is determined which of them is larger, and the larger one is set as the maximum wheel speed VWRMX.

Next, in S110, the left and right rear wheels 30,
32, the slip amount VS of the one with the higher rotation speed
LP is calculated. Specifically, the maximum wheel speed VW
RMX and the vehicle speed VSO (the average value of the rotational speeds of the left and right front wheels 26 and 28 detected by the rotation sensors 90 and 92) are read, and then the vehicle speed VSO is subtracted from the maximum wheel speed VWRMX, and the resulting value is set to 0. If this is the case, the slip amount VSLP is itself set, but if it is smaller than 0, 0 is set as the slip amount VSLP.

Subsequently, in S120, the yaw rate differential D
Threshold values KDVY and KVY between VY and yaw rate VY are determined. These threshold values are used later in S600 to determine whether or not to start the operation of the portions of the brake device 68 related to the left and right front wheels 26, 28 (hereinafter abbreviated as front wheel brake control). Specifically, the slip amount VSLP is read, and the threshold value is determined accordingly. The threshold value KDVY of the yaw rate derivative is also the threshold value KV of the yaw rate VY.
Y also has a large value in a region where the slip amount VSLP is small,
In a region where the slip amount VSLP is large, a small value is determined.

In S200, it is determined whether or not a correction value for yaw rate VY can be calculated, that is, whether or not a yaw rate correction value can be calculated. Left and right front wheels 2
It is determined whether the brakes 6 and 28 are not operated and the vehicle is in a straight running state. If so, the calculation of the yaw rate correction value is permitted, and if not, the calculation is prohibited. Specifically, first, in S205 of FIG. 4, the steering angle Θ is read as the steering angle ΘNEW, and thereafter, in S210, S215, and S220,
Since the brake pedal 10 is not depressed, the signal XBSW of the brake switch 82 is OFF, and
Whether the target hydraulic pressure BBPF related to the front wheel brake control is 0, whether the absolute value of the steering angle ΘNEW is smaller than a positive constant K1, and the differential value of the steering angle ΘNEW (the steering angle ΘNE
It is determined whether or not the absolute value of (W-steering angle ΘOLD) is smaller than a positive constant K2. If any one of the determinations is NO, the yaw rate correction value calculation is performed in a state where it is reset to 0 in S225. The yaw rate correction permission flag XYC indicating that prohibition is set and permission is set when set to 1 is reset to 0, and preparation for the next yaw rate correction value calculation availability determination is performed in S230. On the other hand, if all the determinations are YES, S23
5, the vehicle speed VSO is read, and in S240, it is determined whether the vehicle speed VSO is equal to or higher than 10 km / h.
If S, the yaw rate correction permission flag XYC is set to 1 in S245, and the flow shifts to S230.

In S300, a yaw rate correction value is calculated. Specifically, first, in S302 of FIG. 5, the rotational speeds VWFL, VWFR and the steering angle の of the left and right front wheels 26, 28 are read, and in S304, the current original yaw rate RVYNEW (the current original yaw rate at the present moment) is expressed by the equation RVYNEW = It is calculated by (VWFR−VWFL) / [2 · L · cos (Θ / GS)]. 2 · L, Θ, and GS are the front wheel tread, the steering angle, and the steering gear ratio, respectively, and as shown in FIG. 8, the actual steering angle Θ / GS of each of the left and right front wheels 26, 28.
Are assumed to be equal to each other, and the length 2 · L · cos (Θ / G) of the front tread 2 · L in a direction perpendicular to the center plane of the front wheel tire is considered.
S) and the rotational speed difference VWFR-VW between the left and right front wheels 26, 28.
The original yaw rate RVYNEW of this time is calculated from FL. And this ex-Yaw rate RVYN
The EW is smoothed by the smoothing amount N1 in S306 to be the current smoothed source yaw rate SVY, and preparation for the next smoothed original yaw rate SVY is prepared in S308.

Thereafter, in S312, it is determined whether or not the yaw rate correction permission flag XYC is set to 1. If the determination is NO, S314 and subsequent steps are skipped. If YES, S314, S316, S31
8, S320 and S322, respectively, the vehicle speed V
Whether the SO is 20 km / h or more, 40 km / h or more, 60 km / h or more, 80 km / h or more, 100 km / h or more Are determined, and if those determinations are NO, respectively, S324 and S32
6, S328, S330, and S332, the yaw rate correction value VYC20 (10 km / h ≦ vehicle speed VSO
<Yaw rate correction value in case of 20 km / h), VYC4
0 (yaw rate correction value when 20 km / h ≦ body speed VSO <40 km / h), VYC60 (yaw rate correction value when 40 km / h ≦ body speed VSO <60 km / h), V
YC80 (60 km / h ≦ Yaw rate correction value when vehicle speed VSO <80 km / h), VYC100 (80 km / h ≦
The yaw rate correction value when the vehicle speed VSO <100 km / h is read, and the old yaw rate correction value VYCOLD
On the other hand, if all the determinations are YES, the yaw rate correction value VYC120 (1) is determined in S334.
(Yaw rate correction value when 00 km / h ≦ body speed VSO) is read and set as the old yaw rate correction value VYCOLD. In S336, this smoothing original yaw rate S
VY is read, and in S338, this is smoothed by using the old yaw rate correction value VYCOLD and by the smoothing amount N2, and the resulting value is converted to the new yaw rate correction value VYCNE.
W.

S340, S342, S344, S34
6 and S348, the vehicle speed VSO is 20
km / h or more, 40 km / h or more, 6
0 km / h or more, 80 km / h or more,
It is determined whether the speed is 100 km / h or more. If the determinations are NO, S350, S352, S35
In steps S4, S356, and S358, the new yaw rate correction value VYCNEW is set to the new yaw rate correction value VYC2.
0, VYC40, VYC60, VYC80, VYC10
On the other hand, if all the determinations are YES, the new yaw rate correction value VYCNEW is determined in S360.
Is a new yaw rate correction value VYC120. In short, the yaw rate correction values VYC20, 40, 60,
80, 100, and 120 are the original Yurate SVs
It is updated using Y.

After the execution of S300, in S400, the yaw rate VY and the yaw rate differential DVY are calculated. That is, as shown in FIG.
420, S422, S424, S426, S428, respectively, whether the vehicle speed VSO is 10 km / h or more, 20 km / h or more, 40 km / h or more, 60 km / h or more Is determined, whether or not the speed is 80 km / h or more, or whether or not the speed is 100 km / h or more.
0, 0 in S432, S434, S436, and S438, respectively, the yaw rate correction values VYC20, VYC4
0, VYC60, VYC80, and VYC100 are set as the appropriate yaw rate correction values OVYC. On the other hand, if all the determinations are YES, the yaw rate correction value VYC120 is set as the appropriate yaw rate correction value OVYC in S440.

Thereafter, in S442, a proper yaw rate correction value OVYC is subtracted from the present smoothing source yaw rate SVY to calculate a yaw rate VY (this is one mode of the corrected yaw rate in the present invention).
At 444, the yaw rate differential DVY is obtained by subtracting the previous yaw rate BVY from the yaw rate VY.
Is calculated, and preparation for the next yaw rate differentiation is performed in S446.

Therefore, when the program shown in the figure is executed when the vehicle is traveling straight ahead, even if there is an effective radius difference between the left and right front wheels 26, 28, only the current original yaw rate SVY
And the proper yaw rate correction value OVYC substantially match, and the yaw rate VY becomes substantially zero. On the other hand, when the program shown in the figure is executed at the time of turning the vehicle, the yaw rate correction value VYC stored in association with the vehicle speed VSO at the time of acquisition of the current yaw rate correction value VYC from the current original yaw rate SVY. Yaw rate VY by being deducted
Is calculated, the yaw rate VY becomes a value sufficiently close to the actual yaw rate even if there is an effective radius difference between the left and right front wheels 26, 28.

In S500, the acceleration GVSO of the vehicle body
Is calculated. Specifically, the vehicle speed V between this time and the previous time
SO and BVSO are read, and a vehicle acceleration GVSO is calculated as a difference between the two.

In S600, the start and end of the front wheel brake control is determined. It is determined whether or not the start condition of the front wheel brake control is satisfied and whether or not the end condition is satisfied, and the ON / OFF of the front wheel brake control flag XCFB is performed based on the determination result. The front wheel brake control is started when a spin occurs,
The determination as to whether the start condition of the front wheel brake control is satisfied is detection of the occurrence of spin.

At S610 in FIG. 6, it is determined whether or not the front wheel brake control is being performed based on whether or not the front wheel brake control flag XCFB is ON. If the determination is NO, it is determined at S615, S620, S625, and S630, respectively. Whether the vehicle speed VSO is equal to or lower than a threshold value KVSO, whether the brake pedal 10 is depressed and the signal XBSW of the brake switch 82 is ON, and whether the slip amount VSLP is equal to or lower than the threshold value KVSLP. It is determined whether the vehicle body acceleration GVSO is equal to or greater than the threshold value KGVSO.
If it is S, the determination after the determination is not performed.

If all the above determinations are NO, S635
In step S640, the absolute value of the yaw rate differential DVY and the absolute value of the yaw rate
It is determined whether or not VY, KVY or more, and if either determination is YES, the front wheel brake control flag XCFB is turned ON in S645. In S650, the turning direction of the vehicle is determined based on whether the steering angle Θ is positive or negative,
Based on the determination, the turning direction flag XSTA is set to S65.
5, set to OFF or ON in S660. On the other hand, if the determinations in S635 and S640 are both NO, S645 and subsequent steps are skipped.

On the other hand, if the determination in S610 is YES, it is determined in S665 and thereafter whether or not the termination condition is satisfied. In S665, it is determined whether or not the brake pedal 10 is depressed based on whether or not the brake switch 82 is ON. In S670, it is determined whether or not the direction of the current steering angle Θ is the same as the direction indicated by the steering direction flag XSTA. It is determined whether or not the steering direction has been reversed (whether or not the steering position of the steering wheel has changed beyond the neutral position), and if any determination is YES, the front wheel brake control flag XCFB is determined in S680.
Is turned off. If the determinations in S665 and S670 are both NO, in S675, the acceleration GVWRMX of the larger one (maximum wheel speed VWRMX) of the rotational speeds of the right and left rear wheels 30, 32 is the threshold value KKGW. It is determined whether or not the following is true.
If ES, the front wheel brake control flag XCFB is turned off in S680, and if NO, S680 is skipped.

After execution of S600, control of the hydraulic pressure source 40 is performed in S700. Specifically, first, it is determined whether or not the pressure switch 52 is ON. If the pressure switch 52 is ON, the pump motor 48 is started, and if it is OFF, the pump motor 48 is stopped. Since hysteresis is given to ON and OFF of the pressure switch 52, the brake fluid is stored in the accumulator 46 at a certain range of pressure.

Finally, in S800, hydraulic control of the front wheel cylinders 16, 18 is performed. First, FIG.
In S810, ON / OFF of the front wheel brake control flag XCFB is determined. If the front wheel brake control flag XCFB is ON in the determination routine of S600, the control current IBP of the electromagnetic hydraulic pressure control valve 62 is determined to be a value corresponding to the predetermined instruction hydraulic pressure KBPF in S815, and in S820 An initial hydraulic pressure KDPF for pressure reduction control at the end of the control is set as a target hydraulic pressure BBPF. Also, in S825, the electromagnetic on-off valve 6
4 and 66 are switched so that the front wheel cylinders 16 and 18 are disconnected from the master cylinder 12 and communicate with the hydraulic pressure source 40, and the pump motor 48 is started. Then, in S830, the control current IBP is output, and a hydraulic pressure having a height corresponding to the control current IBP is supplied to the front wheel cylinders 16 and 18. Since the control current IBP is determined to have a magnitude corresponding to the predetermined instruction pressure KBPF in S815, the front wheel cylinders 16 and 18 are supplied with the instruction liquid pressure KBPF. As a result, the left and right front wheels 26, 28 are locked, and their cornering forces are substantially balanced with those of the left and right rear wheels 30, 32, thereby suppressing spin.

On the other hand, if the determination in S810 is NO, the control current I
Whether the BP is greater than the control current corresponding to the initial hydraulic pressure KDPF is used to determine whether the pressure reduction control is the first time. If the determination is YES, the control current IBP is set to the pressure reduction initial value corresponding to the initial hydraulic pressure KDPF in S840, which is output in S830. Therefore, when S835 is executed next, the determination becomes NO, and in S845, the target value BBPF of the hydraulic pressure control is reduced by the fixed amount KDDPF. The determination in S835 is N
When S845 is executed for the first time after reaching O, since the initial hydraulic pressure KDPF has been set in S840,
The target hydraulic pressure BBPF is reduced by a fixed amount KDDPF from the initial hydraulic pressure. Thereafter, it is determined whether or not the target hydraulic pressure BBPF is equal to or greater than 0 in S850, but initially YES is determined, and S855 and S860 are skipped and S
865 and S830 are executed. In S865, the control current IBP corresponding to the target hydraulic pressure BBPF is determined, and is output in S830. By repeating the above, the hydraulic pressure of the front wheel cylinders 16 and 18 is gradually reduced from the initial hydraulic pressure KDPF.

Thereafter, if the target hydraulic pressure BBPF becomes smaller than 0, the determination in S850 becomes NO, the target hydraulic pressure BBPF is set to 0 in S855, and the electromagnetic on-off valves 64, 66 are set to the front wheel cylinders 16, 18 in S860.
Is connected to the master cylinder 12, and the pump motor 48 is stopped. Then, in S865, the control current I corresponding to the target hydraulic pressure 0
Since the BP is determined and output at S830, the hydraulic pressure of the front wheel cylinders 16, 18 becomes zero.
Thereafter, since the determination in S850 is NO, the electromagnetic hydraulic control valve 62 is maintained in a state where the hydraulic pressure is maintained at 0 until the front wheel brake control flag XCFB is turned ON again.

When the spin determination is performed using the smoothed original yaw rate SVY without correcting it, if the effective radii between the left and right wheels 26 and 28 do not sufficiently match, spin actually occurs. It is not detected even though it is present, or incorrect determination is made that spin is occurring even though spin is not actually occurring, and the turning performance improvement effect is not obtained as planned The problem arises. However, in this embodiment, the spin determination is performed by correcting the smoothed original yaw rate SVY.
The actual yaw rate can be accurately estimated, and the spin determination can be accurately performed, so that the effect of improving the reliability of the vehicle control device can be obtained.

In this embodiment, the left and right wheels 2
Rather than immediately calculating the original yaw rate RVYNEW, OLD from the difference between the rotational speeds VWFL, VWFR of the left and right wheels 26, 28, the change in the distance between the tire center planes of the left and right wheels 26, 28 due to the change in the steering angle Θ is taken into account. Former Yaw Rate RVYN
Since EW and OLD are calculated, an effect is obtained that the actual yaw rate can be accurately estimated regardless of the presence or absence of the effective radius difference between the left and right wheels 26 and 28 and the magnitude of the steering angle Θ. However, estimating the actual yaw rate in consideration of the change in the steering angle Θ is not essential for implementing the present invention.

As is clear from the above description, all the steps in FIG. 5 correspond to the yaw rate correction value acquiring step, and S410 to 442 in FIG. 1 and S302 to 308 in FIG. 5 correspond to the corrected yaw rate acquiring step. It is. Also, times
The rotation sensors 90 and 92 and the steering angle sensor 84 are
It is equivalent to a sensor.

In the present embodiment, the yaw rate is estimated from the difference between the rotational speeds of the left and right front wheels 26 and 28, which are the steering wheel and the non-drive wheel.
Estimating the yaw rate from the rotational speed difference between the left and right rear wheels 30, 32, which are non-steering wheels and driving wheels, can also be used to estimate the yaw rate of the left and right non-steering wheels and non-driving wheels like the left and right rear wheels of a front wheel drive type vehicle. It is also possible to estimate the yaw rate from the rotation speed difference.

Although the embodiment of the present invention has been described above, the present invention can be implemented in various modified and improved embodiments based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a flowchart showing details of a part of a spin suppression program in a vehicle control device using a yaw rate estimation method according to one embodiment of the present invention.

FIG. 2 is a system diagram showing the vehicle control device.

FIG. 3 is a flowchart showing the entire spin suppression program.

FIG. 4 is a flowchart showing details of a part of the spin suppression program.

FIG. 5 is a flowchart showing details of a part of the spin suppression program.

FIG. 6 is a flowchart showing details of a part of the spin suppression program.

FIG. 7 is a flowchart showing details of a part of the spin suppression program.

FIG. 8 is a diagram for explaining calculation of a yaw rate in FIG. 5;

FIG. 9 is a graph showing an example of a relationship between a vehicle speed, an effective radius difference between left and right wheels, and an estimated yaw rate.

[Explanation of symbols]

 26 front left wheel 28 front right wheel 70 control device 84 steering angle sensor 90 rotation sensor 92 rotation sensor 94 rotation sensor 96 rotation sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B60T 8/00 B60T 8/24 B60T 8/58 G01C 21/00

Claims (2)

(57) [Claims] 1. A method for estimating a yaw rate of a vehicle body using a rotational speed difference between wheels provided on right and left sides of a vehicle body, wherein an original yaw rate is acquired using the rotational speed difference between the right and left wheels when the vehicle goes straight. the former yaw rate which is the taken as the yaw rate correction value, and the vehicle speed at which it was acquired
A yaw rate correction value obtaining step of storing the yaw rate correction value in association with the vehicle speed, obtaining an original yaw rate using the rotational speed difference between the left and right wheels when the vehicle turns, and from the original yaw rate , the same vehicle speed as the vehicle speed at the time when it was obtained. Associated and stored
Yaw rate estimating method characterized by comprising a correction yaw rate obtaining step of obtaining a correction yaw rate by subtracting the a yaw rate correction value. 2. In the yaw rate correction value obtaining step,
The yaw rate correction value is determined for a plurality of predetermined vehicles.
Former yaw rate is obtained when going straight ahead within the body speed range
To the vehicle speed range to which the vehicle speed at the time of
Acquired, and in the corrected yaw rate acquiring step,
The vehicle speed at the time when the original yaw rate was acquired during turning belongs to
The yaw rate correction value corresponding to the vehicle speed range
Correction yaw rate by subtracting from the original yaw rate at the time
2. The yaw rate estimation method according to claim 1, wherein a site is acquired.
Law.