JP2956285B2 - Vehicle steering angle abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a steering angle of a vehicle and detecting an abnormality in the steering angle.

[0002]

2. Description of the Related Art Conventionally, various types of vehicular traveling control devices such as an anti-skid control device for a vehicle have been proposed which input a steering angle of a vehicle and perform control in accordance with the steering angle. When the angle is used for the vehicle travel control device, the steering angle requires high accuracy and high reliability.

Therefore, an apparatus for detecting an abnormality in the steering angle based on the correspondence between the steering angle and the wheel speed, in which the speed difference between the left wheel and the right wheel changes according to the steering angle, and improving the reliability of the steering angle (for example, Japanese Patent Application Laid-Open No. No. 2-195224) is known. This device monitors an estimated steering angle obtained from a difference between left and right wheel speeds and a detected steering angle obtained from a steering sensor signal, and detects any abnormality when a state in which the difference between the two is equal to or more than a predetermined value continues for a predetermined time or more. .

[0004]

However, in the above conventional apparatus, when different diameter tires are mounted, since the diameters of the tires are different, a deviation occurs between the left and right wheel speeds, and the estimated steering angle is correctly calculated. Could not. Therefore, in the above-described conventional apparatus, the correspondence between the steering angle and the wheel speed is not established, and there is still a problem in the reliability of the abnormality detection of the steering angle.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and solves the problems of the conventional device, can correctly detect an abnormality in the steering angle, and can improve the reliability of the steering angle. An object of the present invention is to provide an angle abnormality detection device.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned object, a vehicle steering angle abnormality detecting device according to the present invention detects a steering angle of a steering wheel, and detects left and right wheel speeds of the vehicle. Wheel speed detecting means, correcting means for correcting the speed deviation of the left and right wheels of the vehicle based on a predetermined arithmetic expression in order to correct the speed deviation due to the mounting of the different diameter tires, and correcting calculation by at least the correcting means Straight running condition determining means for determining whether the vehicle is in a straight running condition from the magnitude relationship of the corrected speeds of the left and right wheels of the vehicle;
When the traveling state of the vehicle determined by the straight traveling state determination unit and the steering angle detected by the steering angle detection unit do not correspond to each other, a steering angle abnormality detection unit that detects abnormality of the steering angle is provided. It is characterized by having.

The steering angle abnormality detection means includes: when the straight traveling state determination means determines that the vehicle is traveling straight, and when the steering angle detection means detects a steering angle equal to or larger than a predetermined value, and It is determined that the steering angle is abnormal when it is determined by the straight traveling state determination means that the vehicle is not traveling straight and when a steering angle smaller than a predetermined value is detected by the steering angle detection means. .

When the steering angle abnormality is detected by the steering angle abnormality detecting means, the detected steering angle is gradually reduced to zero. Further, when the straight traveling state determining means determines that the vehicle is in a straight traveling state, a neutral position calculating means for calculating an estimated neutral position of the steering based on the steering angle of the steering detected by the steering angle detecting means. A neutral position determining unit that determines whether an estimated neutral position of the steering is calculated by the position calculating unit when the wheel speed abnormality detecting unit detects an abnormality in the wheel speed; and the neutral position determining unit. And stopping means for stopping the calculation of the estimated neutral position of the steering by the neutral position calculating means when it is determined that the estimated neutral position of the steering has been calculated.

[0009]

In the vehicle steering angle abnormality detecting device according to the present invention having the above-described structure, the speed deviation between the left and right wheels of the vehicle is corrected by the correction means based on a predetermined arithmetic expression. by this,
It is possible to correct the speed deviation between the left and right wheels of the vehicle caused by the mounting of the different diameter tires. When the speed deviation of the left and right wheels of the vehicle is corrected by the correction unit, at least from the magnitude relationship of the corrected speeds of the corrected left and right wheels of the vehicle, whether or not the vehicle is in the straight traveling state is determined by the straight traveling state determination unit. Since the determination is made, the traveling state of the vehicle is correctly determined regardless of the presence or absence of the wheel speed deviation. When the traveling state of the vehicle determined by the straight traveling state determination means and the steering angle detected by the steering angle detection means do not correspond to each other, an abnormality in the steering angle is detected by the steering angle abnormality detection means. . Therefore, the problem that the correspondence between the steering angle and the wheel speed is not established is solved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an anti-skid control device, which performs anti-skid control according to a detected steering angle detected from a steering system of a vehicle, corrects a neutral position of the detected steering angle, and adjusts a steering angle. Is performed, and the processing at the time of abnormality is performed.

FIG. 1 is a block diagram of this embodiment. As shown in FIG. 1, an anti-skid control device 1 detects a steering angle of a vehicle and outputs a detection signal, a steering angle sensor 2, counts the detection signals of the steering angle sensor 2, and outputs a steering angle signal. 3, each wheel 4a, 5a, 6a, 7a of the vehicle
Wheel speed sensors 4, 5, 6, 7 for detecting the rotational speed of the vehicle and outputting speed signals, an electronic control unit (hereinafter referred to as "ECU") 8 for inputting signals from these, and depression of a brake pedal 9a. A master cylinder 9 for generating a hydraulic pressure corresponding to the amount, a brake hydraulic actuator 10 for adjusting the hydraulic pressure of the master cylinder 9 under the control of the ECU 8, and a supply and discharge of the adjusted hydraulic pressure to each of the wheels 4a, 5a, 6a, 7a. Wheel cylinders 4b, 5b, 6b, which apply a braking force to
7b.

Further, the anti-skid control device 1 has, as detectors, a brake switch 11 for detecting operation of the brake pedal 9a and a vehicle speed sensor 12 for detecting vehicle speed.

As shown in FIG. 2, the steering angle sensor 2 includes a slit plate 2a press-fitted into the steering shaft 20,
It is composed of two sets of photo interrupts 2b and 2c arranged at positions sandwiching the slit plate 2a. When the slit plate 2a blocks and transmits the optical paths of the photo interrupts 2b and 2c with the rotation of the steering shaft 20, the steering angle sensor detects a phase shift by a phase difference determined according to the disposition position of the photo interrupts 2b and 2c. A signal is output. Therefore, the steering direction and the steering amount can be detected by the transition of the output state of the steering angle sensor first detection signal SS1 from the photo interrupt 2b and the steering angle sensor second detection signal SS2 from the photo interrupt 2c.

The steering angle sensor first detection signal SS1 and the steering angle sensor second detection signal SS2 are input to the counter 3 shown in FIG. The ECU 8 includes a CPU 8a, a ROM 8
b, the RAM 8c, and the backup RAM 8d are configured as a logical operation circuit, and input / output via the common bus 8e. The wheel speed signals detected by the wheel speed sensors 4, 5, 6, and 7 are transmitted through the waveform shaping circuit 8h and the input / output unit 8f, and the transmission signal of the counter 3 and the detection signal of the vehicle speed sensor 12 are transmitted through the input / output unit 8f. Are input to the CPU 8a. On the other hand, it outputs a control signal to the brake hydraulic actuator 10 via the output unit 8g and the drive circuit 8i.

Next, the operation of the apparatus shown in FIG. 1 will be described. The description of the operation related to the anti-skid control is omitted, and the neutral correction processing of the steering angle, the abnormality determination of the steering angle, and the processing at the time of the abnormality are described.

The apparatus shown in FIG. 1 starts operation when power is supplied, and ends operation when power is cut off. When power is supplied to the device, the counter 3 counts a change in the steering angle from a count value 0 based on a signal from the steering angle sensor 2 and outputs the count value to the ECU 8 as a transmission signal. For this reason, the steering position at the start of power supply is set to the neutral position, and a process of correcting the neutral steering angle after the start of power supply is required.

FIG. 3 is a flowchart showing a steering angle calculation process executed by the ECU 8. When power is supplied to the ECU 8 and the process reaches step 100, registers and memories for subsequent arithmetic processing are initialized.

In step 200, a count value indicating the steering angle is input from the counter 3. In step 300, a steering angle calculation process for converting the count value input from the counter 3 into a steering angle θ is performed to obtain a detected steering angle θ (n).

The detected steering angle θ (n) is obtained by converting the count value C of the counter 3 from the following equation (1) to the previous detected steering angle θ (n−1) (C (n) −C (n−1)). ).

[0020]

(1) θ (n) = θ (n−1) + α · (C (n) −C (n−1)) where α is a coefficient.

In step 400, wheel speed signals are input from the wheel speed sensors 4, 5, 6, and 7, and in step 5
At 00, the uncorrected wheel speed V _Xi (i = L, R) is obtained. V
_XL is the left wheel speed before correction, and V _XR is the right wheel speed before correction. Then, a corrected wheel speed V _Wi described later is calculated by multiplying the uncorrected wheel speed V _Xi by a correction coefficient K _S calculated in step 630 described later. In this embodiment, only the left wheel speed is corrected, and the right wheel speed is not corrected. Therefore, by multiplying the correction coefficient K _S before correction left wheel speed V _XL, calculates the correction left wheel speed V _WL as follows.

[0022]

[Number 2] V _WL = K _S · V _XL However, when the correction coefficient K _S has not been calculated, the correction coefficient K _S = 1.

Further, since the right wheel speed is not corrected, the right wheel speed before correction V _XR = the corrected right wheel speed V _WR .

[0024]

## _EQU3 ## V _WR = V _XR Then, the corrected wheel speed is filtered and sampled from the following equation.

[0025]

V _WR ^* (n) = _kVW · _VWR (n) + (1− _kVW ) · _VWR ^* (n−1)

[0026]

V _WL ^* (n) = k _VW · V _WL (n) + (1−k _VW ) · V _WL ^* (n-1) where k _VW = 1/32, V _WR ^* (n) , V _WR ^* (n−
1) the previous value and the current value of ^{_{V WR *, V WL * (}} n), V WL *
(N-1) is the previous value and current value of V _WL ^* , and V _WR (n) is V
The current value of _WR , V _WL (n), is the current value of V _WL .

In step 600, step 300 and step 300 are executed.
Steering angle θ and wheel speed V obtained in step 500_WiSteering from
Angle neutral position θ_CIs calculated. Done in step 600
Steering angle neutral position θ_CIs shown in FIG.
In FIG. 4, first, in step 610, step 50 is executed.
Wheel speed V obtained at 0 _WiJudgment of wheel slip condition from
I do. Here, the slip state is one of the following conditions
Is true.

That is, (1) the change rate d of the wheel speed V _Wi
V _Wi is greater than or equal to a predetermined value A, and the vehicle is in an acceleration / deceleration state.

[0029]

[6] | wheel speed V _Wi rate of change |> A (2) the absolute value of the difference between the left and right wheel speed the rate of change | dV _WR -dV
_WL | is greater than or equal to the predetermined value B, and the acceleration / deceleration states of the left and right wheels are different.

[0030]

| V _WR change rate−V _WL change rate |> B where A and B are predetermined values.

If any of the above conditions (1) and (2) is satisfied, it is determined that the wheel is slipping, and the slip determination flag is turned on. On the other hand, if neither (1) nor (2) is established, the slip determination flag is turned off. In order to prevent the flag from fluttering (hunting), a predetermined delay time t is provided in the above (1) and (2). That is, in this flowchart, FIG.
As shown in the above, once the flag is turned on, even if none of the above conditions (1) and (2) are satisfied,
The flag is kept on until a predetermined delay time t elapses from the time when it is determined that these conditions are not satisfied.

After performing the slip determination processing, step 6
Proceeding to 20, it is determined whether permission conditions for speed deviation correction of the left and right wheels are satisfied. The correction of the speed deviation between the left and right wheels is a process for correcting the occurrence of a deviation in the ratio between the left and right wheel speeds when the vehicle can be regarded as traveling substantially straight when different-diameter tires are mounted. In this embodiment, the left wheel speed is corrected.

The condition for permitting the correction of the speed deviation of the left and right wheels, that is, the condition under which the vehicle can be regarded as substantially in a straight running state, is that the following conditions (3) to (6) are satisfied. That is,
(3) The wheel speed _VWi must be equal to or higher than a predetermined value C because it is easy to make an erroneous determination during low-speed running.

[0034]

## EQU8 ## Wheel speed V _Wi ≧ C (4) The slip determination flag is off and the wheels are not slipping.

[0035]

(9) The absolute value of the change rate of the steering angle θ is equal to or less than the predetermined value D, and the vehicle is not in a sharp turning state.

[0036]

| Change rate of steering angle θ | <D (6) The absolute value of the final steering angle θ _S (to be calculated later) is equal to or smaller than a predetermined value E, and the vehicle is not in a large turning state.

[0037]

| Final steering angle θ _S | ≦ E where C, D, and E are predetermined values and final steering angle θ
_S is a steering angle obtained in step 700 described later.

When all of the above conditions (3) to (6) are satisfied, it is determined that the right and left wheel speed deviation correction permission condition is satisfied, and the routine proceeds to step 630. If any one of the above conditions (3) to (6) is not satisfied, the process proceeds to step 640 without performing step 630.

In step 630, the speed deviation of the left and right wheels is corrected. First, in the timing chart shown in FIG. 6, at the timing when it is determined in step 620 that the speed deviation correction permission condition is satisfied (indicated by a circle in FIG. 6), the pre-correction wheel speed V _Xi is filter-sampled. _O , a correction coefficient K _S is calculated.

[0040]

(Equation 12) Here, V _XR ^* and V _XL ^* are the right wheel speed before correction and the left wheel speed before correction, which are sampled by filter, and are calculated by the following equations.

[0041]

V _XR ^* (n) = k _O · V _XR (n) + (1−k _O ) · V _XR ^* (n−1)

[0042]

V _XL ^* (n) = k _O · V _XL (n) + (1−k _O ) · V _XL ^* (n−1) where k _O = 1/64, V _XR ^* (n) , V _XR ^* (n−
1) is the current and previous values of V _XR ^* , V _XL ^* (n), V _XL ^*
(N-1) is the current value and the previous value of V _XL ^* , and V _XR (n) is V
The current value of _XR , V _XL (n), is the current value of V _XL .

The correction coefficient K _S is calculated by the following equation.

[0044]

K _s (n) = k ₁ · K _O + (1−k ₁ ) · K _S · (n−1) where k ₁ = １ ／.

Thereafter, the process proceeds to step 640, where it is determined from the following conditions whether or not the vehicle is actually traveling straight.
This condition is the condition in step 620. (3) Wheel speed V _Wi ≧ C (4) Slip determination flag is off (5) | Change rate of steering angle θ <D and corrected left wheel speed after filter sampling The ratio between V _WL ^* and the corrected right wheel speed V _WR ^* is equal to or less than a predetermined value K. That is, (7) the right and left wheel speeds are almost the same.

[0046]

[Expression 16] MAX (V _WL ^* , V _WR ^* ) <K · MIN (V _WL ^* , V _WR ^* ) If all the above conditions are satisfied, it is determined that the vehicle is actually running straight regardless of the diameter of the tire. Then, the straight traveling determination flag is turned on. If at least one of the above conditions is not satisfied, the straight traveling determination flag is turned off.

In step 640, it is determined whether the vehicle is actually turning. This determination condition is, in addition to the above determination conditions (3) and (5),
(8) Corrected left wheel speed V after filter sampling
The ratio between _WL ^* and the corrected right wheel speed _VWR ^* is equal to or greater than a predetermined value K '.

[0048]

MAX (V _WL ^* , V _WR ^* )> K ′ · MIN (V _WL ^* , V _WR ^* ) Note that K <K ′.

When all of the above conditions are satisfied, it is determined that the vehicle is actually turning, regardless of the diameter of the tire, and the turning determination flag is turned on. If at least one of the above conditions is not satisfied, the turning determination flag is turned off.

If it is determined in step 640 that the straight traveling determination flag is on, the process proceeds to step 650. On the other hand, if the straight traveling determination flag is off, the process proceeds to step 660 without performing the process of step 650.

In step 650, the steering angle θ obtained in step 300 is sampled, and the integrated value Σθ of the sampled steering angle is obtained, and the routine proceeds to step 660. In step 660, it is determined whether the steering angle sampled in step 650 has reached a predetermined number n (= 128). When it is determined that the predetermined number n (= 128) has been reached,
Proceed to step 670. On the other hand, a predetermined number n (= 128)
If it is determined that the current time has not reached, the present routine is terminated.

In step 670, an average steering angle ave θ _C is calculated from the integrated value of the steering angles Δθ sampled in step 650 and the sampled number n every predetermined number of samplings, based on the following equation.

[0053]

(Equation 18) Then, the steering angle neutral position θ _C is calculated from the following equation.

[0054]

Equation 19 _{θ C (i) = K B} · ave θ C (i) + (1-K B) · θ C (i-1) _{However, θ C (i), θ} C (i-1) is , is the current value and the previous value of the steering angle neutral position θ _C. The K _B is a weighting factor, a K _B = 1/2.

When the routine for calculating the steering angle neutral position θ _C is completed, the routine proceeds to step 700. Step 700
In calculates a final steering angle theta _S from the difference between the steering angle neutral position theta _C from the steering angle and wheel speed calculated in step _{600 (= θ-θ C)} .

When the processing in step 700 is completed, the flow advances to step 800. In step 800, a process for determining an abnormality in the steering angle and the wheel speed based on the final steering angle θ _S and the left and right wheel speeds V _WL and V _WR is performed. FIG. 7 shows an abnormality determination routine performed in step 800.

In FIG. 7, first, at step 810, it is determined whether the steering angle is abnormal. The steering angle is determined to be abnormal, the following conditions, the number 20 is the time which satisfies a predetermined time T _1.

[0058]

(Equation 20) That is, the condition in step 620 (3) the wheel speed V _Wi ≧ C (4) In addition to the fact that both of the slip determination flags are OFF, (9) the final steering angle θ despite the determination that the vehicle is traveling straight ahead _S exceeds a predetermined value G. (10) The final steering angle θ _S is equal to or smaller than the predetermined value H even though it is determined that the vehicle is turning.

When the above (9) or (10) is satisfied, it is determined that the steering angle is abnormal, and the routine proceeds to step 820, where the steering angle abnormality flag is turned on. On the other hand, when Expression 20 is not established, it is determined that the steering angle is not abnormal, and Step 83
The program proceeds to 0 and the steering angle abnormality flag is turned off.

In step 840, the abnormality of the wheel speed (vehicle
One wheel disconnection of the wheel speed sensor) is determined. Wheel speed is abnormal
Is determined when the following condition is satisfied and the expression 21 is a predetermined value.
Interval T _TwoIt is time to hold between.

[0061]

(Equation 21) That is, (11) it is easy to make an erroneous determination at low speeds
The larger one of the wheel speeds V _Wi is equal to or higher than the predetermined value I. (12) The smaller one of the wheel speeds V _Wi is the larger one.
/ 8. That is, the speed difference between the inner wheel and the outer wheel which is considered in a turning state or the like is larger than the speed difference.

When the above equation (21) is satisfied, that is, (1
When 1) and that (12) is satisfied for a predetermined time T _2, determines that the wheel speed error (one wheel disconnection of wheel speed sensors), and turns on the wheel speed abnormality flag proceeds to step 850.

When Formula 21 is not satisfied, it is determined that the wheel speed is not abnormal (there is no disconnection of one wheel of the wheel speed sensor), and
Proceeding to step 860, the wheel speed abnormality flag is turned off. When the processing of steps 850 and 860 is completed, the present routine ends.

[0064] Then, the process proceeds to step 900, processing by performing in accordance with the presence or absence of the steering angle and wheel speed abnormality determination in step 800, calculates an estimated steering angle theta _X.
The calculated estimated steering angle theta _X is used in anti-skid control apparatus. 8 and 9 show the abnormality processing routine performed in step 900. In the abnormality processing routine is performed and the estimated steering angle theta _X calculation processing in FIG. 8, a vehicle speed V _b calculation processing in FIG.

First, in step 910, it is determined whether the steering angle abnormality flag determined in step 800 is on or off.
If the steering angle abnormality flag is off, the process proceeds to step 915. On the other hand, if the steering angle abnormality flag is on, the process proceeds to step 940. In step 940, an estimated steering angle process when the steering angle is abnormal is performed. Specifically, a process of reducing the estimated steering angle θ _X calculated later by a predetermined angle Δθ and gradually returning to 0 is performed. Thereafter, the flow proceeds to step 945, and outputs a steering angle abnormality signal.

At step 915, it is determined whether the wheel speed abnormality flag determined at step 800 is on or off.
Wheel speed abnormality flag proceeds to step 920 if it is off, to calculate the final steering angle theta _S as the estimated steering angle theta _X.

On the other hand, if the wheel speed abnormality flag is ON in step 915, the process proceeds to step 925,
It determines whether the steering angle neutral position theta _c is calculated at 70. Here, to stop the steering angle neutral position theta _c is determined to be calculated, the calculation of the steering angle neutral position theta _c at step 600 proceeds to step 930.
That, and abnormality occurs in the wheel speed, the abnormality determined as wheel speed value was also calculated by calculating the steering angle neutral position theta _c with since there is no reliable steering angle neutral position theta _c as well as stop the calculation, calculates an estimated steering angle theta _X using a steering angle neutral position theta _c which is previously calculated.

Meanwhile, when the steering angle neutral position theta _c is determined not to be calculated in step 925, step 93
Proceed to 5, processing for calculating the filtered estimated steering angle from the value theta _X a steering angle of the steering every predetermined distance as disclosed in JP-B-63-2802. The running distance at this time is calculated by accumulating pulse signals from a normal wheel speed sensor (a wheel speed sensor that can be regarded as having not broken one wheel).

When the estimated steering angle θ _X calculation process in FIG. 8 is completed, in step 950 in FIG. 9, the on / off state of the wheel speed abnormality flag determined in step 800 is determined again. If the wheel speed abnormality flag is on, the process proceeds to step 960. If the wheel speed abnormality flag is off, the routine proceeds to step 955. In step 955, the vehicle speed _Vb is calculated from the following equation.

[0070]

_Vb = ( _VWL ^* + _VWR ^* ) / 2 After the vehicle speed _Vb is calculated in step 955, this routine is terminated.

If the wheel speed abnormality flag is off at step 950, the process proceeds to step 960. At step 960, the vehicle speed V _b is calculated from the wheel speed of the larger left and right wheel speed (the wheel speed sensor can be regarded as not disconnected).
Is calculated. Then, the process proceeds to a step 965, and after outputting a wheel speed abnormality signal, the present routine is terminated.

As described above, in the present embodiment, step 62
At 0,630, a speed deviation correction process is performed, a straight running determination is made using the corrected wheel speed, and an abnormality in the steering angle is determined by using the straight running determination result. An abnormality can be reliably determined without erroneously determining an abnormality between the steering angle and the wheel speed when the wheel speed is disturbed.

In this embodiment, the steering angle sensor 2 and the counter 3 correspond to the steering angle detecting means, and the wheel speed sensors 4, 5, 6, and 7 correspond to the wheel speed detecting means. Step 630 shown in FIG. Corresponds to the correction means, and step 640
Corresponds to the straight traveling state determination means, and step 810 shown in FIG. 7 corresponds to the steering angle abnormality detection means.
Corresponds to wheel speed abnormality detecting means, step 670 shown in FIG. 5 corresponds to neutral position calculating means, step 925 shown in FIG. 8 corresponds to neutral position determining means, and step 930
Corresponds to the stopping means.

The vehicle steering angle abnormality detecting device of the present invention is not limited to the above-described embodiment, but can be variously modified as described below, for example. The abnormality determination of the steering angle in step 810 may be performed by comparing the determined estimated steering angle θ _XA estimated from the left and right wheel speeds with a predetermined value _Kb in a state where the steering angle is fixed (almost does not move).

First, the maximum value ΔV _W of the speed difference between the left and right wheels (=
V _WR −V _WL ) and the estimated steering angle θ _XA from the following equation:
Is calculated.

[0076]

_XXA = K ・ ΔV _W / V _b where K = (wheel base) ・ (steering gear ratio) / (tread), and V _b is the vehicle speed calculated from Equation 22.

Then, the abnormality of the steering angle is determined based on the following conditions.

[0078]

(Equation 24) Here, _Kb is a predetermined value.

If all of the above conditions are satisfied a predetermined number of times (for example, 20 times) or more, it is determined that the steering angle is abnormal. That is, in addition to the condition in step 620, (3) the wheel speed V _Wi ≧ C (4) the slip determination flag is both off, (13) the steering angle θ is equal to or less than the predetermined value J, and Not in the state. (14) The fluctuation range of the judgment estimated steering angle θ _XA is larger than a predetermined value _Kb . That is, it is estimated that the steering is largely performed.

When all of the above conditions are satisfied, the small steering angle θ is calculated based on the signal from the steering angle sensor despite the fact that it is estimated that the steering is largely performed. And turns on the steering angle abnormality flag.

[0081] In the process of calculating the steering angle neutral position theta _c at step 935, if the rate of change of the steering angle (or change width) is less continuously for a predetermined time, the average value of the steering angle sampled within the prescribed time Steering angle neutral position θ _c
It is good.

The steering angle abnormality detecting device of the present invention can be employed not only in the anti-skid control device but also in other control devices using the steering angle. For example, a suspension for controlling the roll of the vehicle in accordance with the steering angle. It can be used for a control device.

[0083] When the steering angle neutral position theta _c at step 925 is determined not to be calculated, the steering angle neutral position theta _c
, The estimated steering angle θ _X may be gradually returned to 0 as in step 940.

[0084]

As described above in detail, in the vehicular steering angle abnormality detecting apparatus according to the present invention, the correcting means performs the correction calculation of the speed deviation between the left and right wheels of the vehicle, so that the speed deviation caused by the mounting of the different diameter tires. Can be corrected, the abnormality of the steering angle can be reliably detected even when the tires with different diameters are mounted, and there is an excellent effect that the reliability of the steering angle can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram in an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a steering angle sensor 2.

FIG. 3 is a flowchart showing a steering angle calculation process executed by an electronic control unit 8;

FIG. 4 is a flowchart illustrating a steering angle neutral position calculation process.

FIG. 5 is an explanatory diagram illustrating slip state determination.

FIG. 6 is an explanatory diagram for explaining timing for performing speed deviation correction.

FIG. 7 is a flowchart illustrating an abnormality determination process.

FIG. 8 is a flowchart showing a process at the time of abnormality.

FIG. 9 is a flowchart showing a process at the time of abnormality.

[Explanation of symbols]

 2 steering angle sensor 4 wheel speed sensor 5 wheel speed sensor 6 wheel speed sensor 7 wheel speed sensor 8 electronic control unit

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriyuki Nakajima 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-2-195224 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) G01B 21/00-21/32

Claims (4)

(57) [Claims] 1. A steering angle detecting means for detecting a steering angle of a steering, a wheel speed detecting means for detecting left and right wheel speeds of a vehicle, and a predetermined arithmetic expression for correcting a speed deviation caused by mounting different diameter tires. Correction means for performing a correction calculation of the speed deviation of the left and right wheels of the vehicle based on the relationship between at least the correction speed of the left and right wheels of the vehicle calculated and corrected by the correction means; When the traveling state of the vehicle determined by the straight traveling state determination means does not correspond to the steering angle detected by the steering angle detection means, the abnormality of the steering angle is detected. And a steering angle abnormality detecting device for detecting the steering angle abnormality. 2. The steering angle abnormality detection means, when the straight traveling state determination means determines that the vehicle is traveling straight, and when the steering angle detection means detects a steering angle equal to or greater than a predetermined value; and It is determined that the steering angle is abnormal when it is determined by the straight traveling state determination means that the vehicle is not traveling straight and when a steering angle smaller than a predetermined value is detected by the steering angle detection means. The vehicle steering angle abnormality detection device according to claim 1. 3. The vehicle according to claim 1, wherein when a steering angle abnormality is detected by the steering angle abnormality detecting means, a process of gradually decreasing the detected steering angle to zero is performed. For detecting abnormal steering angle. 4. When the straight traveling state determination means determines that the vehicle is in a straight traveling state, a neutral steering position is calculated based on the steering angle of the steering detected by the steering angle detection means. A position calculating unit; a neutral position determining unit that determines whether an estimated neutral position of the steering is calculated by the position calculating unit when an abnormality in the wheel speed is detected by the wheel speed abnormality detecting unit; 2. A stopping means for stopping the calculation of the estimated neutral position of the steering by the neutral position calculating means when the position determining means determines that the estimated neutral position of the steering is calculated. 4. The vehicle steering angle abnormality detection device according to claim 1.