JP3255108B2 - Failure determination device for yaw rate sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yaw rate sensor for detecting a yaw rate of a vehicle such as an automobile, and more particularly, to a failure determination device for a yaw rate sensor.

[0002]

2. Description of the Related Art As one type of failure determination device for a yaw rate sensor mounted on a vehicle such as an automobile, for example, as disclosed in Japanese Patent Application Laid-Open No. 63-207772 filed by the present applicant, a yaw rate sensor is used. A yaw rate sensor failure determination device that determines that a yaw rate sensor has failed when a change in the detected yaw rate is abnormally large has already been proposed.

[0003]

In general, the range of the rate of change of the detected yaw rate generated as the vehicle travels and the range of the rate of change of the yaw rate indicated by the yaw rate sensor when the yaw rate sensor fails are partially overlapped. Therefore, even if a large change in the detected yaw rate occurs, it cannot be distinguished whether the change is a phenomenon caused by a sudden change in the behavior of the vehicle due to disturbance or a phenomenon caused by a failure of the yaw rate sensor. Therefore, in the above-described conventional failure determination device, the reference value of the failure determination of the yaw rate sensor must be set to a high value. Therefore, the failure is determined even though the yaw rate sensor has actually failed. May not be possible.

[0004] Further, there is already known a failure determination device which calculates an estimated yaw rate based on a difference between left and right wheel speeds and determines that a yaw rate sensor has failed when a deviation between the estimated yaw rate and the detected yaw rate is large. However, even if the yaw rate sensor does not fail, the deviation between the estimated yaw rate and the detected yaw rate may increase depending on the turning situation of the vehicle. Must be set high, and therefore a failure of the yaw rate sensor cannot be detected until the deviation between the estimated yaw rate and the detected yaw rate becomes very large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems in the conventional yaw rate sensor failure determination apparatus, and the main object of the present invention is not only the change rate of the detected yaw rate but also the detected yaw rate. The purpose of the present invention is to determine the failure of the yaw rate sensor early and surely by considering the size and the like.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a yaw rate sensor for detecting a yaw rate of a vehicle, which calculates a change rate of a yaw rate detected by the yaw rate sensor. Means, means for calculating an estimated yaw rate based on parameters other than the yaw rate of the vehicle, means for comparing the rate of change of the detected yaw rate with a first threshold value, and comparing the detected yaw rate with a second threshold value Means for comparing the estimated yaw rate with a third threshold, and the magnitude of the detected yaw rate within a predetermined time from the time when the magnitude of the rate of change of the detected yaw rate is equal to or greater than the first threshold. Is greater than or equal to the second threshold and if the magnitude of the estimated yaw rate is less than the third threshold, it is determined that the yaw rate sensor has failed. A yaw rate sensor failure determination device having a failure determination means (the configuration of claim 1) or a yaw rate sensor failure determination device that detects a yaw rate of a vehicle calculates a reference yaw rate of the vehicle based at least on a steering angle and a vehicle speed. Means for calculating the rate of change of the detected yaw rate of the yaw rate sensor, means for calculating the estimated yaw rate based on parameters other than the yaw rate of the vehicle, and comparing the rate of change of the detected yaw rate with a first threshold. Means for comparing a first deviation between the detected yaw rate and the reference yaw rate with a second threshold value, and comparing a second deviation between the estimated yaw rate and the reference yaw rate with a third threshold value Means for performing the detection within a predetermined time from the time when the magnitude of the change rate of the detected yaw rate becomes equal to or greater than the first threshold value. Failure determination means for determining that the yaw rate sensor has failed when the magnitude of the first deviation is greater than or equal to the second threshold and the magnitude of the second deviation is less than the third threshold. This is achieved by a failure determination device for a yaw rate sensor having the above configuration.

In general, even if the rate of change of the detected yaw rate is large, it is due to a sudden change in the behavior of the vehicle due to a disturbance. If the yaw rate sensor is normal, the detected yaw rate and the estimated yaw rate are changed. The magnitude instantaneously increases and then decreases. However, if the magnitude of the change rate of the detected yaw rate increases due to the failure of the yaw rate sensor, the magnitude of the detected yaw rate increases instantaneously and remains large, whereas the magnitude of the estimated yaw rate increases. The size is not so large.

According to the configuration of the first aspect, the magnitude of the detected yaw rate is equal to or greater than the second threshold within a predetermined time from the time when the magnitude of the change rate of the detected yaw rate is equal to or greater than the first threshold. When the magnitude of the estimated yaw rate is less than the third threshold, it is determined that the yaw rate sensor has failed. Therefore, immediately after the failure of the yaw rate sensor, the failure of the yaw rate sensor is reliably determined.

In general, when the rate of change of the detected yaw rate increases due to a failure of the yaw rate sensor, the magnitude of the detected yaw rate increases instantaneously and then remains large. On the other hand, since the magnitude of the estimated yaw rate changes substantially corresponding to the reference yaw rate, the magnitude of the deviation between the detected yaw rate and the reference yaw rate becomes large after the magnitude of the detected yaw rate sharply changes. On the other hand, the magnitude of the deviation between the estimated yaw rate and the reference yaw rate is a small value.

According to the configuration of the second aspect, the deviation between the detected yaw rate and the reference yaw rate is defined as a first deviation, and the deviation between the estimated yaw rate and the reference yaw rate is defined as a second deviation. When the magnitude of the first deviation is greater than or equal to the second threshold and the magnitude of the second deviation is less than the third threshold within a predetermined time from the time when In this configuration, if the yaw rate sensor fails, the failure of the yaw rate sensor is reliably determined immediately after that, and the failure of the yaw rate sensor is determined during the turning of the vehicle. Becomes possible.

[0011]

According to a preferred aspect of the present invention, in the configuration of the first aspect, the failure determining means determines that the rate of change of the detected yaw rate is greater than or equal to a first threshold value. If the situation where the magnitude of the detected yaw rate is equal to or greater than the second threshold value and the magnitude of the estimated yaw rate is less than the third threshold value continues for a reference time or more within a predetermined time from the reference time, it is determined that the yaw rate sensor has failed. (Preferred embodiment 1).

According to another preferred aspect of the present invention, in the configuration according to the second aspect, the failure determination means is configured to perform the determination from the time when the magnitude of the change rate of the detected yaw rate becomes equal to or greater than the first threshold value. If the situation where the magnitude of the first deviation is greater than or equal to the second threshold and the magnitude of the second deviation is less than the third threshold within a predetermined time continues for a reference time or more, a failure of the yaw rate sensor will occur. It is configured to determine (preferred mode 2).

According to another preferred aspect of the present invention, in the configuration of the first aspect, the failure determining means includes:
The magnitude of the detected yaw rate is greater than or equal to the second threshold and the magnitude of the estimated yaw rate within a predetermined time immediately after the reference time has elapsed from the time when the magnitude of the change rate of the detected yaw rate is greater than or equal to the first threshold. Is determined to be a failure of the yaw rate sensor when is smaller than a third threshold (preferred mode 3).

According to another preferred embodiment of the present invention, in the configuration of claim 2 described above, the failure determining means includes:
The magnitude of the first deviation is greater than or equal to the second threshold and within a predetermined time immediately after the reference time has elapsed from the time when the magnitude of the change rate of the detected yaw rate is greater than or equal to the first threshold, and When the magnitude of the deviation is less than the third threshold, it is determined that the yaw rate sensor has failed (preferred mode 4).

According to another preferred aspect of the present invention, in the configuration of the first aspect, the means for calculating the estimated yaw rate is based on the estimated yaw rate based on the wheel speed of the steered wheels and the lateral acceleration of the vehicle. The estimated yaw rate is calculated, and the failure determination means is configured to determine whether both the estimated yaw rate based on the wheel speed of the steered wheels and the estimated yaw rate based on the lateral acceleration of the vehicle are respectively less than a corresponding third threshold. (Preferred embodiment 5).

According to another preferred aspect of the present invention, in the configuration of the second aspect, the means for calculating the estimated yaw rate is based on the estimated yaw rate based on the wheel speed of the steered wheels and the lateral acceleration of the vehicle. An estimated yaw rate is calculated, and the failure determination means calculates a third yaw rate corresponding to both the deviation between the estimated yaw rate based on the wheel speed of the steered wheels and the reference yaw rate and the deviation between the estimated yaw rate based on the lateral acceleration of the vehicle and the reference yaw rate. It is configured to determine whether the difference is less than the threshold (preferred mode 6).

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the accompanying drawings, in which several preferred embodiments are shown.

FIG. 1 is a schematic configuration diagram showing a first embodiment of a failure determination device for a yaw rate sensor according to the present invention.

In FIG. 1, reference numeral 10 denotes an estimated yaw rate calculation block. Estimated yaw rate calculation block 1
To 0, signals indicating the wheel speeds Vwfl and Vwfr of the front left and right wheels are input from wheel speed sensors 12FL and 12FR that detect the wheel speeds of the front left and right wheels that are the steered wheels. The estimated yaw rate calculation block 10 calculates the estimated yaw rate γa of the vehicle based on the wheel speeds Vwfl and Vwfr of the left and right front wheels as described later.

In FIG. 1, reference numerals 14 to 20 denote a detected yaw rate change rate calculation block and first to third comparison blocks, respectively. The detected yaw rate change rate calculation block 14 calculates a detected yaw rate change rate γd based on a signal indicating the detected yaw rate γ input from the yaw rate sensor 22. A first comparison block 16 compares the rate of change γd of the detected yaw rate with a first threshold γdc, a second comparison block 18 compares the detected yaw rate γ with a second threshold γc, and a third comparison block. 20 compares the estimated yaw rate γa with the third threshold γac.

Further, in FIG. 1, reference numeral 24 denotes a failure determination block. The failure determination block 24 receives signals indicating the respective comparison results from the first to third comparison blocks 16 to 20, and determines whether or not the yaw rate sensor 22 has failed based on those signals, as described later. Output the judgment result.

Incidentally, the failure determination device actually has a CPU, a ROM, a RAM, and an input / output port device, for example, and may be a microcomputer having a general configuration connected to each other by a bidirectional common bus. . The yaw rate sensor 22 and a lateral acceleration sensor 26 to be described later detect the yaw rate γ and the lateral acceleration Gy of the vehicle as positive when the vehicle turns left.

Next, a failure determination routine of the yaw rate sensor according to the first embodiment will be described with reference to a flowchart shown in FIG.

First, in step 10, a signal indicating the detected yaw rate γ detected by the yaw rate sensor 22 is read, and in step 20, the affirmative determination is made in step 50 described later. It is determined whether or not the count value T1 of the timer for managing the elapsed time is positive, that is, whether or not the timer has already been started. If a negative determination is made, the process proceeds to step 50, If a positive determination is made, step 3
Go to 0.

In step 30, it is determined whether or not the count value T1 of the timer is equal to or greater than a reference value T1c (positive constant). If a negative determination is made, step 60 is executed.
When the affirmative determination is made, the count value T1 of the timer is reset to 0 in step 40, and then the process proceeds to step 120.

In step 50, the change rate γd of the detected yaw rate is calculated according to the following equation (1) using γf as the previous detected yaw rate γ, and the absolute value of the change rate γd of the detected yaw rate is set to the reference value γdc (positive value). It is determined whether or not the value is equal to or more than a constant. If the determination is negative, the process proceeds to step 120, and if the determination is affirmative, the count value T1 of the timer is set to ΔT in step 60 (see FIG. 2).
(Positive constant equal to the cycle time of the control flow shown in FIG. 7).

## EQU1 ## γd = γ−γf

In step 70, the detected yaw rate γ
Is determined whether or not the absolute value of is greater than or equal to a reference value γc (positive constant).
If the determination is affirmative, step 80 is reached.
The estimated yaw rate γvw based on the wheel speed is calculated according to the following equation 2 based on the wheel speeds Vwfl and Vwfr of the front left and right wheels and the tread Tf of the front wheel.

## EQU2 ## γvw = (Vwfr−Vwfl) / Tf

In step 90, it is determined whether or not the absolute value of the estimated yaw rate γvw based on the wheel speed is smaller than a reference value γvwc (positive constant). If a negative determination is made, the process proceeds to step 120. When an affirmative determination is made, the following number is calculated in step 100 based on the lateral acceleration Gy of the vehicle detected by the lateral acceleration sensor 26 (not shown in FIG. 1) and the vehicle speed V detected by the vehicle speed sensor 28. After the estimated yaw rate γgy based on the lateral acceleration is calculated according to 3, the routine proceeds to step 110.

Γgy = Gy / V

In step 110, it is determined whether or not the absolute value of the estimated yaw rate γgy based on the lateral acceleration is smaller than a reference value γgyc (positive constant). If a negative determination is made, the process proceeds to step 120. After the count value T2 of the timer is reset to 0 in step 130, it is determined in step 130 that the yaw rate sensor 22 is normal.
When an affirmative determination is made, the process proceeds to step 150 after the count value T2 of the timer is counted up by ΔT in step 140.

In step 150, it is determined whether or not the count value T2 of the timer is equal to or greater than a reference value T2c (a positive constant equal to or less than T1). If a negative determination is made, the process proceeds to step 130; When an affirmative determination is made, a determination is made in step 160 that the yaw rate sensor 22 is out of order, and a signal indicating this is provided by a signal indicating that the yaw rate sensor 22 is malfunctioning, such as a vehicle behavior control device using the detection result of the yaw rate sensor 22. Output to the control device.

In general, even if the rate of change γd of the detected yaw rate γ is large in a situation where the yaw rate sensor 22 is normal, if the change is due to a sudden change in the behavior of the vehicle due to disturbance, the detected yaw rate and The magnitudes of the estimated yaw rate γvw based on the wheel speed and the estimated yaw rate γgy based on the lateral acceleration become small after instantaneously increasing. However, if a failure such as a disconnection or a short circuit occurs in the yaw rate sensor and the magnitude of the rate of change of the detected yaw rate becomes large due to this, the magnitude of the detected yaw rate becomes large after momentarily increasing. In contrast to the value, the magnitude of the estimated yaw rate is not so large.

According to the first embodiment, it is determined in step 50 whether or not the absolute value of the rate of change γd of the detected yaw rate has become equal to or greater than the reference value γdc. A predetermined time T1c from the time when the absolute value of the rate of change γd of the detected yaw rate becomes equal to or more than the reference value γdc.
Within the absolute value of the detected yaw rate γ is equal to or greater than the reference value γc, the absolute value of the estimated yaw rate γvw based on the wheel speed is less than the reference value γvwc, and the absolute value of the estimated yaw rate γgy based on the lateral acceleration is less than the reference value γgyc. It is determined whether or not a certain situation has continued for the reference time Tc2 or more, and when an affirmative determination is made, it is determined that the yaw rate sensor 22 has failed.

Therefore, according to the first embodiment shown in the drawings, it is determined that the yaw rate sensor 22 is faulty despite the fact that it is normal, or that the yaw rate sensor 22 is faulty even though it is faulty. The failure of the yaw rate sensor 22 can be accurately and reliably determined without making a determination, and the failure of the yaw rate sensor 22 can be determined immediately after the failure of the yaw rate sensor 22.

In particular, according to the illustrated first embodiment, the absolute value of the detected yaw rate γ is changed to the reference value γc within a predetermined time T1c after the absolute value of the rate of change γd of the detected yaw rate becomes equal to or more than the reference value γdc. Whether or not the situation where the absolute value of the estimated yaw rate γvw based on the wheel speed is less than the reference value γvwc and the absolute value of the estimated yaw rate γgy based on the lateral acceleration is less than the reference value γgyc has continued for the reference time Tc2 or more Is determined, the absolute value of the detected yaw rate γ is equal to or larger than the reference value γc within a predetermined time T1c, and the absolute value of the estimated yaw rate γvw based on the wheel speed is set to the reference value γvw.
less than c and an estimated yaw rate γgy based on the lateral acceleration
Of the yaw rate sensor 22 compared to the case where it is determined whether or not a situation has occurred in which the absolute value of
It is possible to accurately and reliably determine whether or not the device has failed.

Further, the estimated yaw rate based on the wheel speed as the estimated yaw rate is excellent in followability to the actual yaw rate of the vehicle, but is likely to include an error due to the slipping of the wheel in braking / driving. On the other hand, the estimated yaw rate based on the lateral acceleration of the vehicle has no problem due to the error caused by the braking / driving slip of the wheels, but has poor followability with respect to the actual yaw rate of the vehicle.

According to the first embodiment shown, the estimated yaw rate γvw based on the wheel speed is used as the estimated yaw rate γa.
And an estimated yaw rate γgy based on the lateral acceleration is calculated,
The absolute value of the detected yaw rate γ is equal to or more than the reference value γc within a predetermined time T1c, the absolute value of the estimated yaw rate γvw based on the wheel speed is less than the reference value γvwc, and the absolute value of the estimated yaw rate γgy based on the lateral acceleration is the reference value. If the situation in which the value is less than the value γgyc continues for the reference time Tc2 or more, it is determined that the yaw rate sensor 22 has failed. Therefore, the estimated yaw rate γ based on the wheel speed is determined as the estimated yaw rate γa.
Compared to the case where only one of the estimated yaw rate γgy based on vw or the lateral acceleration is calculated, it is possible to accurately and reliably determine whether or not the yaw rate sensor 22 is out of order.

FIG. 3 is a schematic configuration diagram showing a second embodiment of the yaw rate sensor failure judging device according to the present invention.
In FIG. 3, the same components as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG.

In this embodiment, a reference yaw rate calculation block 32 is provided. The reference yaw rate calculation block 32 receives a signal indicating the vehicle speed V from the vehicle speed sensor 28, and detects a steering angle θ. Angle sensor 3
From 0, a signal indicating the steering angle θ is input. The reference yaw rate calculation block 32 calculates a reference yaw rate γt of the vehicle based on the vehicle speed V and the steering angle θ as described later.

In this embodiment, a first deviation calculation block 34 and a second deviation calculation block 36 are provided. The first deviation calculation block 34 calculates a first deviation Δγ1 between the detected yaw rate γ input from the yaw rate sensor 22 and the reference yaw rate γt, and the second deviation calculation block 36 calculates an estimated yaw rate calculation block 10
Estimated yaw rate γa and reference yaw rate γ
A second deviation Δγ2 from t is calculated.

Further, the second comparison block 18 in this embodiment compares the first deviation Δγ1 with the second threshold value Δγ1c, and the third comparison block 20 compares the second deviation Δγ2 with the third threshold value Δγ2c, and the results of these comparisons are input to the failure determination block 24 as in the first embodiment.

Next, a failure determination routine of the yaw rate sensor according to the second embodiment will be described with reference to a flowchart shown in FIG. In FIG. 4, the same steps as those shown in FIG. 2 are denoted by the same step numbers as those shown in FIG.

In this embodiment, steps 10 to 10
60 and steps 120 to 160 are executed in the same manner as in the first embodiment. In step 82 executed after step 60, the actual steering angle δ of the front wheels is calculated based on the steering angle θ, Using H as a wheel base and Kh as a stability factor, a target yaw rate γe is calculated according to the following equation 4, and a reference yaw rate γt is calculated according to the following equation 5 using T as a time constant and s as a Laplace operator. The target yaw rate γe may be calculated in consideration of the dynamic yaw rate by taking into account the lateral acceleration Gy of the vehicle.

[0043]

Γe = V * δ / (1 + Kh * V ² ) * H

Γt = γe / (1 + T * s)

In step 84, the first deviation Δγ1 is calculated according to the following equation (6). In step 86, it is determined whether the absolute value of the first deviation Δγ1 is greater than or equal to the reference value Δγ1c (positive constant). If a negative determination is made, the process proceeds to step 120, and if an affirmative determination is made, the wheel speeds Vwfl and Vwfr of the left and right front wheels and the front wheel Estimated yaw rate γ based on tread Tf according to the following equation (7)
a is calculated.

[0045]

## EQU6 ## Δγ1 = γ−γt

Γa = (Vwfr−Vwfl) / Tf

In step 104, the second deviation Δγ2 is calculated according to the following equation (8). In step 106, it is determined whether the absolute value of the second deviation Δγ2 is smaller than the reference value Δγ2c (positive constant). If a negative determination is made, the process proceeds to step 120 if a negative determination is made, and the process proceeds to step 140 if a positive determination is made.

[Equation 8] Δγ2 = γa−γt

Generally, the yaw rate sensor 22 fails,
When the rate of change γd of the detected yaw rate γ increases due to this, the magnitude of the detected yaw rate increases instantaneously and remains large, whereas the magnitude of the estimated yaw rate γa increases. Is substantially changed corresponding to the reference yaw rate γt, so that the magnitude of the first deviation Δγ1, which is the deviation between the detected yaw rate and the reference yaw rate, becomes large after the magnitude of the detected yaw rate sharply changes. On the other hand, the magnitude of the second deviation Δγ2, which is the deviation between the estimated yaw rate and the reference yaw rate, is a small value.

According to the second embodiment, it is determined in step 50 whether or not the absolute value of the change rate γd of the detected yaw rate has become equal to or greater than the reference value γdc. A predetermined time T1c from the time when the absolute value of the rate of change γd of the detected yaw rate becomes equal to or more than the reference value γdc.
The absolute value of the first deviation Δγ1 between the detected yaw rate γ and the reference yaw rate γt is equal to or greater than the reference value Δγ1c, and the absolute value of the second deviation Δγ2 between the estimated yaw rate γa and the reference yaw rate γt is less than the reference value Δγ2c. It is determined whether or not a certain situation has continued for the reference time Tc2 or more, and when an affirmative determination is made, it is determined in step 160 that the yaw rate sensor 22 has failed.

Therefore, according to the second embodiment shown in the drawing, similarly to the case of the above-described first embodiment, the yaw rate sensor 2
2 can be accurately and reliably determined, and the failure of the yaw rate sensor can be determined immediately after the failure of the yaw rate sensor 22.

In the case of the first embodiment described above, when the vehicle is in a turning state in which the magnitudes of the estimated yaw rates γvw and γgy exceed the corresponding reference values γvwc and γgyc, respectively, the yaw rate sensor fails. However, in the second embodiment, the magnitudes of the first and second deviations Δγ1 and Δγ2 using the reference yaw rate γt as the reference amount correspond to the corresponding reference values. Since the comparison is made, the failure of the yaw rate sensor can be reliably determined even when the vehicle is in the turning traveling state as described above.

In particular, according to the second embodiment shown in the drawing, within a predetermined time T1c from the time when the absolute value of the rate of change γd of the detected yaw rate becomes equal to or greater than the reference value γdc, the first yaw rate γt and the reference yaw rate γt The absolute value of one deviation Δγ1 is equal to or greater than the reference value Δγ1, and the absolute value of the second deviation Δγ2 between the estimated yaw rate γa and the reference yaw rate γt is the reference value Δ
Since it is determined whether or not the situation that is less than γ2c has continued for the reference time Tc2 or more, the absolute value of the first deviation Δγ1 is equal to or more than the reference value Δγ1 and the second deviation Δγ2 within the predetermined time T1c. It is possible to accurately and reliably determine whether or not the yaw rate sensor 22 has failed, as compared to a case where it is determined whether or not a situation where the absolute value is less than the reference value Δγ2c has occurred.

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

For example, in the first embodiment described above,
In step 80, the estimated yaw rate γvw based on the wheel speed is calculated. In step 90, it is determined whether or not the absolute value of the estimated yaw rate γvw is less than the reference value γvwc. The estimated yaw rate γgy based on the lateral acceleration is calculated, and
At zero, the absolute value of the estimated yaw rate γgy is equal to the reference value γgyc.
It is determined whether the number is less than or equal to
The process proceeds to step 140 only when an affirmative determination is made in both of steps 10 and 10. However, when an affirmative determination is made in either step 90 or 110, the process is modified to proceed to step 140. And one of steps 80 and 90 or steps 100 and 110 may be omitted.

In the second embodiment, only the estimated yaw rate based on the wheel speed is calculated in step 102 as the estimated yaw rate γa.
04, the deviation between the estimated yaw rate γa based on the wheel speed and the reference yaw rate γt is calculated as the second deviation Δγ2, but the wheel speed is calculated as the estimated yaw rate as in the first embodiment. Both the estimated yaw rate γvw based on the estimated yaw rate and the estimated yaw rate γgy based on the lateral acceleration of the vehicle are calculated, the deviation between these estimated yaw rate and the reference yaw rate is calculated as the second deviation, and the same determination as in step 106 is performed for each deviation. It may be modified to do so.

Further, in each of the above-described embodiments, when the affirmative determination is made in step 50, the steps after step 60 are immediately executed. For example, as shown in FIGS. As described above, when T1o is set to a positive constant smaller than T1c and the affirmative determination is made in step 20, it is determined in step 26 whether T1 is equal to or greater than T1o, and the negative determination is made. Is performed, the process proceeds to step 120 after T1 is incremented by .DELTA.T in step 28, and the process may proceed to step 30 if a positive determination is made. In this case, steps 120, 140, and 150 may be omitted.

In each of the above embodiments, when a negative determination is made in step 106, step 120 is executed.
Although the count value T2 of the timer is reset to 0 in step (1), step 120 may be omitted, and the count value T2 may be reset to 0 in step 40. In this case, step 7 occurs due to noise or the like.
A negative determination is made at 0, 90, 110 or steps 86, 106, thereby preventing the count value T2 from being reset.

Further, in each of the above-described embodiments, the reference yaw rate γt is calculated based on the steering angle θ and the vehicle speed V according to the above equation (4).
The reference yaw rate γt may be calculated in any manner as long as the reference yaw rate γt is calculated based on the vehicle motion parameters other than the detected yaw rate γd.

For example, the target yaw rate γe may be calculated according to the following equation 9 using K as a positive coefficient. Further, the target yaw rate γ calculated according to the above equation 4 or the following equation 9
e may be corrected by -Ks * Gy * V using Ks as a positive coefficient, thereby eliminating the influence of cant on the road surface.

Γe = K * V * δ

[0059]

As is apparent from the above description, according to the first and second aspects of the present invention, the failure of the yaw rate sensor can be accurately and reliably determined, and the failure of the yaw rate sensor has occurred. Immediately thereafter, the failure of the yaw rate sensor can be determined, and in particular, according to the configuration of the second aspect, the failure of the yaw rate sensor can be accurately and reliably determined even when the vehicle is in a turning state.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a failure determination device for a yaw rate sensor according to the present invention.

FIG. 2 is a flowchart illustrating a failure determination routine of a yaw rate sensor according to the first embodiment.

FIG. 3 is a schematic configuration diagram showing a second embodiment of a failure determination device for a yaw rate sensor according to the present invention.

FIG. 4 is a flowchart illustrating a failure determination routine of a yaw rate sensor according to a second embodiment.

FIG. 5 is a flowchart illustrating a failure determination routine of a yaw rate sensor according to a modification of the first embodiment.

FIG. 6 is a flowchart illustrating a failure determination routine of a yaw rate sensor in a modification of the second embodiment.

[Explanation of symbols]

 10 Estimated yaw rate calculation block 12FL and 12FR Wheel speed sensor 14 Detected yaw rate change rate calculation block 16 First comparison block 18 Second comparison block 20 Third comparison block 22 Yaw rate sensor 24 Failure Discrimination block 26 ... lateral acceleration sensor 28 ... vehicle speed sensor 30 ... steering angle sensor 32 ... reference yaw rate calculation block 34 ... first deviation calculation block 36 ... second deviation calculation block

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI B62D 137: 00 G01P 15/00 Z (58) Field of investigation (Int.Cl. ⁷ , DB name) G01P 21/00 B62D 6 / 00 G01P 15/00

Claims (2)

(57) [Claims] An apparatus for determining a failure of a yaw rate sensor for detecting a yaw rate of a vehicle, means for calculating a change rate of a yaw rate detected by the yaw rate sensor, and means for calculating an estimated yaw rate based on parameters other than the yaw rate of the vehicle. Means for comparing the rate of change of the detected yaw rate with a first threshold, means for comparing the detected yaw rate with a second threshold, and means for comparing the estimated yaw rate with a third threshold, The magnitude of the detected yaw rate is greater than or equal to the second threshold and the magnitude of the estimated yaw rate is less than or equal to the second threshold within a predetermined time from the time when the magnitude of the change rate of the detected yaw rate is greater than or equal to the first threshold. A failure determination device for a yaw rate sensor, comprising: failure determination means for determining that the yaw rate sensor has failed when the value is less than a third threshold value. 2. A device for determining a failure of a yaw rate sensor for detecting a yaw rate of a vehicle, wherein a means for calculating a reference yaw rate of the vehicle based on at least a steering angle and a vehicle speed;
Means for calculating the rate of change of the detected yaw rate of the yaw rate sensor, means for calculating the estimated yaw rate based on parameters other than the yaw rate of the vehicle, means for comparing the rate of change of the detected yaw rate with a first threshold, Means for comparing a first deviation between the detected yaw rate and the reference yaw rate and a second threshold, and means for comparing a second deviation and a third threshold between the estimated yaw rate and the reference yaw rate, The magnitude of the first deviation is greater than or equal to the second threshold within a predetermined time from when the magnitude of the change rate of the detected yaw rate becomes greater than or equal to the first threshold, and A failure determination unit that determines that the yaw rate sensor has failed when the magnitude is less than the third threshold value.