JPH1159462A - Steering angle abnormality detecting sensor and vehicle equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate necessity of using two steering angle sensors and reduce costs by detecting an abnormality of the steering angle sensor based on the deviation between a computed steering angle value obtained by integrating a steering angle amount put out by the steering angle sensor and a steering angle value put out by the steering angle sensor. SOLUTION: A steering angle sensor abnormality detection processing routine is executed at an ECU 1. That is, a computed steering angle value is calculated based on a steering angle change amount 'A' from a steering angle sensor 21, and an estimated steering angle value is calculated based on right and left wheel speeds v1 and v2. Then, a computed steering angle integration average value and an estimated steering angle average value are calculated. Moreover, the estimated steering angle integration average value is subtracted from the computed steering angle integration average value so as to integrate a neutral correction value, and the neutral correction value is substracted from the present steering angle value to have a present steering angle value. And, when an absolute value of the difference between a steering angle value θ2 from a steering angle sensor 21 and the computed steering angle value after neutral correction is larger than a predetermined value, it is determined as abnormality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering angle sensor abnormality detecting device used for a vehicle equipped with a steering angle sensor, and a vehicle equipped with the steering angle sensor abnormality detecting device and a rear wheel steering device.

[0002]

2. Description of the Related Art In vehicle control, particularly in rear wheel steering control, a steering angle value obtained by a steering angle sensor is often used as one of control parameters. In such rear wheel turning control, if an abnormality occurs in the output of the steering angle sensor, erroneous rear wheel turning control is naturally performed. Therefore, it is necessary to monitor the state of the steering angle sensor, and to take any measures if there is any abnormality.

A technique for monitoring the state of the output of the steering angle sensor is disclosed in Japanese Patent Application Laid-Open No. 1-229773. This publication discloses an invention of a rear wheel steering device for a vehicle, in which two steering angle sensors are arranged at different positions of a steering system, and the output values of the respective sensors are compared to each other to thereby provide a steering angle sensor. There is disclosed a technique for detecting an abnormality in a vehicle.

[0004]

However, in spite of the fact that a single steering angle sensor is sufficient from the viewpoint of detecting the steering angle, according to this prior art, two steering angle sensors are used. However, there were problems in securing the mounting position and cost.

[0005]

SUMMARY OF THE INVENTION A steering angle sensor abnormality detecting device according to the present invention is provided to solve such a problem, and detects and outputs a steering angle value and a steering angle change amount. A steering angle sensor abnormality detection device for detecting an abnormality of an angle sensor, comprising: a steering angle calculation unit configured to integrate a steering angle change amount output by the steering angle sensor to calculate a calculated steering angle value; Determining means for determining that the steering angle sensor is abnormal when a deviation between the steering angle value and the calculated steering angle value calculated by the steering angle calculating means exceeds a predetermined value;

The steering angle sensor is disposed in the middle of the steering system of a vehicle, generally detects a change in the steering angle, integrates the change to determine a displacement from a reference point, and uses this as a steering angle value. It is configured to output. Therefore,
In addition to the steering angle value, it is also possible to take out the steering angle change amount as its original data to the outside.

In the steering angle calculating means, a calculated steering angle value is calculated by taking in the steering angle change amount from such a steering angle sensor and integrating it, and the determining means directly obtains the calculated steering angle value and the steering angle sensor. Is compared with the set steering angle value. As long as the rudder angle sensor is operating normally, the rudder angle value and the calculated rudder angle value should match. Conversely, when the deviation between the two exceeds a predetermined value, it is determined that the rudder angle sensor is abnormal. be able to.
It is to be noted that the steering angle sensor abnormality by the determination means includes a case where the steering angle sensor itself has an abnormality and a case where the steering angle sensor output temporarily has an abnormality due to a high steering speed.

The vehicle of the present invention utilizes the output result of such a steering angle sensor abnormality detection device for rear wheel steering drive control, and detects and outputs a front wheel steering angle value and a front wheel steering angle change amount. A steering angle sensor, steering angle calculating means for integrating the front wheel steering angle change amount output from the steering angle sensor to calculate a calculated front wheel steering angle value, and front wheel steering angle value and steering angle calculating means for outputting from the steering angle sensor A steering angle sensor abnormality detecting device having a determination means for determining that the steering angle sensor is abnormal when a deviation from the calculated front wheel steering angle value exceeds a predetermined value, and an output of the steering angle sensor as one of the control parameters. A rear wheel steering device that performs rear wheel steering control and performs rear wheel steering control based on information other than the output of the steering angle sensor when the steering angle sensor abnormality detection device determines that the steering angle sensor is abnormal. Features.

In a rear wheel steering apparatus, a rear wheel target steering angle is generally calculated based on a front wheel steering angle value from a steering angle sensor and a yaw rate from a yaw rate sensor, and the actual rear wheel steering angle is used as the rear wheel target steering angle. The rear wheel steering control is performed so as to match. According to the vehicle of the present invention, when the steering angle sensor abnormality detecting device determines that the steering angle sensor is abnormal, the rear wheel steering device performs rear wheel steering control without using the front wheel steering angle value output by the steering angle sensor. .
Since the wrong front wheel steering angle value is not used for the rear wheel steering control, the accuracy of the rear wheel steering control may be lower than when the steering angle sensor is normal, but no malfunction occurs.

Further, when the rear wheels are steered based on the steering angle value from the steering angle sensor when the steering speed is high, the behavior becomes too large, and the driver may feel uncomfortable.
In this vehicle, even in the case of a temporary steering angle sensor output value abnormality due to high-speed steering, the rear wheel turning control is performed without using the front wheel steering angle value output by the steering angle sensor. Can be reduced.

[0011]

FIG. 1 is a system diagram of a vehicle equipped with a rear wheel steering device provided with a steering angle sensor abnormality detecting device according to an embodiment of the present invention. In this vehicle, a front wheel steering angle value detected by a steering angle sensor is used as one of parameters of rear wheel turning control, and a steering angle sensor abnormality detection device is mounted to detect abnormality of the steering angle sensor. ing.

First, a system of the whole vehicle will be described. The vehicle 2 includes front wheels 4 and 5 attached to a body 3.
And rear wheels 6 and 7. The front wheels 4, 5 are mechanically connected to a front steering gear box 12 via knuckle arms 8, 9 and tie rods 10, 11, respectively.

The gearbox 12 is connected to a steering wheel 14 via a shaft 13 rotatable about its axis. When the shaft 13 rotates about its axis, the rack in the gearbox 12 moves along its longitudinal direction with the assistance of a motor, a hydraulic mechanism or the like in accordance with the rotation of the shaft 13, and engages with the rack. The tie rods 10 and 11 move along the longitudinal direction.

The shaft 13 is connected to the steering wheel 1
4, the tie rods 10, 11 connected to the knuckle arms 8, 9 via hinges move along the longitudinal direction of the front wheels 4, 4 by steering the steering wheel 14. 5 is steered.

The rear wheels 6, 7 are provided with knuckle arms 15, 1
6, connected to both ends of a rear wheel drive shaft 100a of a rear wheel steering actuator 100 via tie rods 17 and 18. The actuator 100 (drive means) has a reduction mechanism internally connected to the motor body 101, and the rear wheel drive shaft 100 linked to this reduction mechanism.
As a moves along its longitudinal direction (indicated by arrow C), the rear wheels 6, 7 are steered in the direction indicated by arrow θ, similarly to the front wheels 4, 5.

The actuator 100 includes a motor body 101
And a rotation position sensor 102 comprising three magnetic pole sensors provided on the motor body 101 and outputting a rotation position signal し た corresponding to the rotor rotation position of the motor body 101, and an actual steering angle δr of the rear wheels 6, 7 being neutral. Neutral sensor 1 that outputs a discrimination signal D indicating that it is on the right or left side of the steering angle δr ₀
03.

Here, the internal structure of the actuator 100 will be described with reference to FIG. FIG.
0 is a sectional view taken along the longitudinal direction of the shaft 100a. The actuator 100 includes a metal cylindrical housing 104, a resin material 105 fixed to an inner wall of the housing 104, a stator 106 fixed to the inner wall of the housing 104 by the resin material 105, and a rotor arranged inside the stator 106. An inner rotor type motor body 101 composed of
7, a speed reduction mechanism 108 for reducing the rotation speed of the motor 7 and transmitting a rotational driving force, and converting the rotational movement of the speed reduction mechanism 108 into a linear movement along the longitudinal direction C to convert the driving force to the drive shaft 100a.
And a conversion mechanism 109 for transmitting the data to the

When the rotor 107 rotates, this driving force is transmitted to the drive shaft 100a via the speed reduction mechanism 108 and the conversion mechanism 109, and the drive shaft 100a moves in the longitudinal direction C. Actuator-side ends 17 of tie rods 17, 18 are provided at both ends of drive shaft 100a.
When the rotor 107 is rotated, the rear wheels 6, 7 are steered because the a and 18a are connected by a ball joint.

The speed reduction mechanism 108 includes a sun gear 108 fixed to the tip of the rotor 107 using the rotor 107 as a driving shaft.
a, a fixed internal gear 108b formed of a resin fixed to the inner surface of the housing 104, and a sun gear 108a
And a plurality of planetary gears 108c interposed between the fixed internal gear 108b and a plurality of planetary gears 108c.

The reduction mechanism 108 includes a fixed internal gear 108b common to the first planetary gear mechanism, a sun gear 108e serving as a driving shaft coaxially arranged with the sun gear 108a of the first planetary gear mechanism, and a sun gear 108e and fixed internal gear 1
And a second planetary gear mechanism including a plurality of planetary gears 108f interposed between the second planetary gears 08b and 08b.

The rotating shaft of the planetary gear 108c of the first planetary gear mechanism is rotatably supported by the tip of an arm 108d fixed to the driving shaft 108e of the second planetary gear mechanism. The drive shaft 108e of the mechanism constitutes a driven shaft of the first planetary gear mechanism. When the sun gear 108a of the first planetary gear mechanism is rotated by rotating the rotor 107, the planet gear 108c meshed with the sun gear 108a and the fixed internal gear 108b revolves around the sun gear 108a, and the planet gear 108c is rotated. The driving shaft 108e of the second planetary gear mechanism fixed to the base end of the arm 108d that supports the shaft rotates coaxially with the sun gear 108a. When the driving shaft 108e of the second planetary gear mechanism rotates, similarly to the first planetary gear mechanism, the nut 109a of the conversion mechanism 109 serving as the driven shaft rotates coaxially with the driving shaft 108e.

The conversion mechanism 109 includes a nut 109a having a screw groove formed on an inner surface thereof, and a screw 10 meshed with the screw groove.
9b. The cylindrical member 104a fixed and communicated with the housing 104 has a ridge 104b extending on the inner surface along the longitudinal direction C, and one end of the drive shaft 100a located inside the cylindrical member 104a has a longitudinal direction. It has a groove 100b extending along C.

The groove 100b of the drive shaft 100a and the ridge 104b of the cylindrical member 104a mesh with each other to form a spline, and restrict rotation about the axis of the drive shaft 100a. Also, the rotor 107 and the nut 109a
Are supported in the housing 104 by a ball bearing B and can rotate with respect to the housing 104. The drive shaft 100a includes a right-end cylindrical member 104a, a nut 109a, sun gears 108e and 10e.
8a, the rotor 107 and the hollow end of the support member 104d fixed to the inner surface of the left end cylindrical member 104c, and can move in the longitudinal direction C with respect to the housing 104.

Since the nut 109a can rotate relative to the drive shaft 100a due to the restriction by the spline, when the nut 109a rotates about the axis of the drive shaft 100a by the rotation of the rotor 107,
The screw 109b of the conversion mechanism 109 forming a part of the drive shaft 100a moves along the longitudinal direction C of the drive shaft 100a, and the rear wheels 6, 7 are steered.

The rotor 107 has a magnet 107a surrounding the outer surface in the circumferential direction. The stator 106 surrounding the rotor 107 is composed of a laminated core 106a of an iron core and the magnet 107a.
10 wound around the laminated core 106a at a position facing the
6b. The control signal P from the ECU 1
6b, the rotor 1
07 rotates. The stator 106 is at least partially buried in the resin material 105 containing glass fiber.

The rotational position of the rotor 107 is detected by a rotational position sensor 102 comprising a magnet 102a fixed to one end of the rotor and a Hall element 102b.
That is, the magnet 102a and the Hall element 102b are arranged in a non-contact manner so that the output signal differs depending on the rotational position of the rotor 107. ECU based on rotation position information of rotor 107 detected by rotation position sensor 102
1 supplies a control signal P to the stator 106 and
7 is rotated. That is, the motor used in the present actuator 100 is a rotating field type DC brushless motor that detects the rotational position of the rotor 107 in a non-contact manner and supplies the control signal P to the stator 106.

The approximate position of the drive shaft 100a in the longitudinal direction C is detected by the neutral sensor 103. That is, the neutral sensor 103 includes an N-pole region 103a and an S-pole region 103b formed by magnetizing a part of the surface of the rear wheel drive shaft 100a, and the magnetized regions 103a and 103b.
Hall element 103 fixed at a position facing 103b
c. N pole region 103a and S pole region 1
03b is aligned along the movement direction C of the rear wheel drive shaft 100a, that is, the longitudinal direction C of the rear wheel drive shaft 100a.

The rear wheels 6, 7 steered by the actuator 100 are driven by the driving force of an engine 19 disposed in the body 3, and are driven by a differential gear 20. Are transmitted to the rear wheels 6 and 7 via the. The engine 19 is started by turning on an ignition switch IG provided in the body 3.

The vehicle 2 has a steering shaft 13
And a wheel speed signal v corresponding to the wheel speed of the front wheels 4 and 5, which detects and outputs a front wheel steering angle value attached to the vehicle.
Wheel speed sensors 22 and 23 for outputting 1 and v2, respectively;
The vehicle includes a speed sensor 24 that outputs a wheel speed signal v3 corresponding to the wheel speeds of the drive wheels 6 and 7, and a yaw rate sensor 25 that outputs a yaw rate γ corresponding to the angular velocity in the vehicle yaw direction.

The steering angle sensor 21 constantly detects the steering angle variation A, and increases or decreases the counter value of a built-in steering angle counter in accordance with the steering angle variation A. The value of this steering angle counter is the front wheel steering angle value θs2. The ECU 1 always calculates the steering wheel angle value θs1 before calculation by taking in the steering angle change amount A and integrating it. Further, the front wheel steering angle value θs1 is corrected using the correction value Δθ calculated by a neutral correction process described later in the ECU 1 so as to match the actual steering angle.

The vehicle speed v of the vehicle 2 is represented by wheel speed signals v1, v2, v
Any one of the three, the average value, or each signal v1, v2, v3
Is weighted as the vehicle speed.

The electronic circuit unit (E) mounted on the vehicle 2
CU) 1 includes the sensors 21 to 25, 102,
The ECU 103 drives the actuator 100 according to the input vehicle state information and controls the turning of the rear wheels 6 and 7 based on the output of the output 103 and the vehicle state information including the ON / OFF information of the ignition switch IG.

That is, the rear wheel steering angle control device provides sensors 21 to 25, 102, 1 for providing vehicle state information to the ECU 1.
03, and an ECU 1 that controls the actuator 100 in accordance with information input from each of these sensors.
CU1 calculates a wheel target steering angle [delta] r ^* After be steered rear wheels 6 and 7 in accordance with the vehicle state information is input, the rear wheels 6 and 7 to the wheel target steering angle [delta] r ^* after the operation The actuator 100 is controlled so that the actual steering angle δr matches.

The rear wheel target steering angle δr ^* is obtained based on the following equation.

Δr ^* = K1 · θs1 + K2 · γ (1) Here, K1 and K2 are coefficients that change according to the vehicle speed (vehicle speed), and the relationship with the vehicle speed is shown in FIGS. 3 and 4, respectively.

The rear wheel target steering angle δr ^* is the yaw rate sensor 2
5 is determined based on the following equation (2), and when the front wheel steering angle sensor 21 is abnormal, the determination is performed based on the equation (3).

Δr ^* = K1 ′ · δf (2) δr ^* = K2 ′ · γ (3) Similarly to K1 and K2, K1 ′ and K2 ′ are coefficients that change according to the vehicle speed (vehicle speed). The relationship with the vehicle speed is shown in FIGS. 5 and 6, respectively.

Next, a description will be given of a steering angle sensor abnormality detecting device according to this embodiment. The function of the steering angle sensor abnormality detection device is one function of the ECU 1 and is achieved by the ECU 1 executing the flowchart shown in FIG. FIG. 7 is a flowchart for detecting an abnormality of the steering angle sensor, and also includes a neutral correction process of the front wheel steering angle value.

The routine for detecting abnormality of the steering angle sensor shown in FIG. 7 is executed by the ECU 1 every 24 ms.

First, in step 201, a calculated steering angle value θs1 and an estimated steering angle value θsa1 of the front wheels are obtained. The calculated steering angle value θs1 is calculated based on the steering angle change amount A from the steering angle sensor 21, and the estimated steering angle value θsa1 is calculated from the following equation (4) based on the left and right wheel speeds v1 and v2.

[0041]

(Equation 1)

Next, the routine proceeds to step 202, where the calculated steering angle integrated average value θms1 and the estimated steering angle integrated average value θmsa
1 is calculated. Here, for the calculated steering angle value θs1 and the estimated steering angle value θsa1, data of the past several hundred times when the vehicle is running at a vehicle speed equal to or higher than a predetermined value are integrated, and the average is obtained. Therefore, steps 201 and 202 are repeatedly executed from when the ignition switch is turned on to IG-ON until the first calculated steering angle integrated average value θms1 and the estimated steering angle integrated average value θmsa1 are calculated.

Once the calculated steering angle integrated average value θms1 and the estimated steering angle integrated average value θmsa1 are once calculated,
By taking in the latest data of the calculated steering angle value θs1 and the estimated steering angle value θsa1 and discarding the oldest data at the same time, each time this routine is executed, the latest calculated steering angle integrated average value θms1 and estimated steering angle integrated average value θmsa1 are calculated. Can be calculated.

In step 202, the calculated steering angle integrated average value θm
When s1 and the estimated steering angle integrated average value θmsa1 are obtained, the routine proceeds to step 203, where the estimated steering angle integrated average value θmsa1 is subtracted from the calculated steering angle integrated average value θms1 to calculate the neutral correction value Δθ. Then, the process further proceeds to step 204, and a value obtained by subtracting the neutral correction value Δθ from the calculated steering angle value θs1 is set as the current calculated steering angle value θs1.

In the neutral correction process, the estimated steering angle value θsa1 calculated based on the left and right wheel speeds is calculated based on the calculated steering angle value θ calculated based on the steering angle change amount A from the steering angle sensor.
It is based on the idea that the steering angle is more accurate than s1 on average.

Next, a steering angle sensor abnormality detection process is performed.
First, a first abnormality determination is performed in step 205. It is determined whether the absolute value of the difference between the steering angle value θs2 from the steering angle sensor 21 and the neutralized corrected steering angle value θs1 is greater than a predetermined value, here 5 deg. In the case of affirmative, it is determined that there is an abnormality, and the routine proceeds to step 206, where the first abnormality flag F1 is set to 1, and
If the result is negative, the process proceeds to step 207 as normal, and the first abnormal flag F1 is set to 0.

The determination in step 205 is based on the premise that the vehicle is traveling normally. In this embodiment, the additional condition is that the vehicle speed is 30 km / h or more.

If an abnormality is determined in step 205, the process proceeds to step 208, where a second abnormality determination is performed to determine whether or not the altitude is abnormal. Here, the absolute value of the difference between the steering angle value θs2 and the calculated steering angle value θs1 is 10 de.
It is determined whether it is greater than g. If affirmative, the process proceeds to step 209, where it is determined that the altitude is abnormal, and the second abnormal flag F
2 is set to 1; if not, the process proceeds to step 210, and it is determined that the altitude is not abnormal, and the second abnormal flag F2 is set to 0.

When the first and second abnormality determinations are completed, it is first determined in step 211 whether the first abnormality flag F1 is 0. If F1 = 1, the flow advances to step 212 to proceed to the fail counter CNT. Is the maximum value of 1
It is set to 0, and further proceeds to step 215 to execute alternative control according to the above equation (3) for rear wheel steering drive control.

If F1 is 0 in step 211, the process proceeds to step 213 to replace the value of the fail counter CNT with a value obtained by subtracting 1 from the previous value. However, the possible value of the fail counter CNT is 0 to 10, and when the previous value is 0, the value is only maintained at 0.

If the processing result of step 213 is not 0, the process proceeds from step 214 to step 215 to execute the alternative control according to the formula (3) for the rear wheel steering drive control. The normal control according to the equation (1) is executed.

If the normal control is selected for the rear wheel turning drive control, it is determined whether or not the second abnormal flag F2 is 1 in step 217, that is, the state has shifted from the second abnormal state to the normal state. Is determined. F
If 2 is 1, the process proceeds to step 218 to calculate the steering angle integrated average value θms1 for calculating the neutral correction value Δθ and the calculated steering angle for several hundred times as basic data of the estimated steering angle integrated average value θmsa1. Value θs1 and estimated steering angle value θsa1
Is cleared, and then the process proceeds to step 219 to replace the second abnormal flag F2 with 0.

If F2 = 0 in decision step 217,
The routine returns to the start without clearing the calculated steering angle value θs1 and the estimated steering angle value θsa1.

As can be understood from the above description, in the present embodiment, when the steering angle sensor is determined to be the first abnormality, the value of the fail counter CNT is set to 10 which is the maximum value, and the rear wheel steering control is performed. After the abnormality determination, the control returns to the normal control only when the normality determination of the steering angle sensor is continuously performed ten times.

The abnormality determination is made when the steering angle sensor itself is abnormal or when the steering angle sensor output is temporarily abnormal due to a high steering speed.
There is one. Therefore, in the latter case, if the normality determination is performed after the abnormality determination, the control returns to the normal control. However, switching between normal control and alternative control many times in a short time is not preferable in terms of control stability.
Even if the normality determination is made after the abnormality determination, the control is not immediately returned to the normal control, but is restored only when the normality determination is continued to some extent.

In the second abnormal state in which the degree of abnormality of the steering angle sensor is large, the calculated steering angle integrated average value θms1 and the estimated steering angle integrated average value θmsa1 for calculating the neutral correction value Δθ are used. Clear all data and start importing basic data from the beginning. In this case, until the calculation of the neutral correction value Δθ is completed, the rear wheel turning control based on the output of the steering angle sensor is temporarily stopped and replaced with the alternative control.

FIG. 8 is a diagram showing an operation of the fail counter CNT and a control state of the rear wheel turning control accompanying the operation of the fail counter CNT when the abnormality detecting device for the steering angle sensor according to the present embodiment is implemented.

When an abnormality is determined at time t1 from a state in which normal control is performed for the rear wheel steering control without any abnormality in the various sensors, the counter value of the fail counter CNT immediately becomes 10, and the rear wheel steering is performed. Control is (3)
The control is switched to the alternative control according to the formula. Thereafter, if the normality determination continues until immediately before time t2, the count value of the fail counter CNT decreases by one each time the normality determination is made, but since the count value does not reach 0, the alternative control is maintained.

At time t2, the abnormality is determined again, and the count value of the fail counter CNT returns to 10. Thereafter, the normality determination continues until immediately before time t3, so that the value of the fail counter CNT decreases. Since the abnormality determination is continuously performed from the time t3 to the time t4, the failure counter C
NT is maintained at 10. After time t4, the normality determination continues, and the count value of fail counter CNT becomes time t5.
And becomes 0. When the fail counter CNT becomes 0, the control state returns to the normal control.

[0060]

As described above, according to the steering angle sensor abnormality detecting device of the present invention, it is not necessary to provide another steering angle sensor for detecting an abnormality of the steering angle sensor. Angle sensor abnormality can be detected.

Further, according to the vehicle of the present invention, when the steering angle sensor itself becomes abnormal or when the steering angle sensor output temporarily becomes abnormal due to a high steering speed, it is determined based on the output of the steering angle sensor. Wheel turning control is stopped. Therefore, erroneous rear-wheel steering or rear-wheel steering that gives a sense of incongruity to the driver can be suppressed.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a vehicle including a steering angle sensor abnormality detection device according to an embodiment of the present invention.

FIG. 2 is a rear-wheel steering drive unit 1 used for rear-wheel steering angle control.
Sectional view showing the structure of 00.

FIG. 3 is a graph showing a constant K1 in a target steering angle calculation formula used for rear wheel steering angle control.

FIG. 4 is a graph showing a constant K2 in a target steering angle calculation formula used for rear wheel steering angle control.

FIG. 5 is a graph showing a constant K1 ′ in a target steering angle calculation formula used for rear wheel steering angle control.

FIG. 6 is a graph showing a constant K2 ′ in a target steering angle calculation formula used for rear wheel steering angle control.

FIG. 7 is a flowchart showing a steering angle sensor abnormality detection process by the ECU 1.

FIG. 8 is a diagram showing an operation of a fail counter CNT and a control state of a rear wheel turning control accompanying the operation of the fail counter CNT when the steering angle sensor abnormality detecting device of the embodiment is implemented.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... ECU, 2 ... vehicle, 6,7 ... rear wheel, 21 ... steering angle sensor, 22,23 ... wheel speed sensor, 25 ... yaw rate sensor, 100 ... rear wheel steering drive means.

Claims (2)

[Claims] A steering angle sensor abnormality detection device for detecting an abnormality of a steering angle sensor that detects and outputs a steering angle value and a steering angle change amount, wherein the steering angle change amount output by the steering angle sensor is integrated. Steering angle calculating means for calculating a calculated steering angle value by using a steering angle when a deviation between the steering angle value output by the steering angle sensor and the calculated steering angle value calculated by the steering angle calculating means exceeds a predetermined value. A rudder angle sensor abnormality detection device comprising: a determination unit that determines that the sensor is abnormal. 2. A steering angle sensor for detecting and outputting a front wheel steering angle value and a front wheel steering angle change amount, and calculating a front wheel steering angle value by integrating the front wheel steering angle change amount output by the steering angle sensor. It is determined that the steering angle sensor is abnormal when the deviation between the front wheel steering angle value output by the steering angle calculating means and the steering angle sensor and the calculated front wheel steering angle value calculated by the steering angle calculating means exceeds a predetermined value. A steering angle sensor abnormality detecting device having determining means, and performing rear wheel turning control using the output of the steering angle sensor as one of the control parameters, and when the steering angle sensor abnormality detecting device determines that the steering angle sensor is abnormal. And a rear wheel steering device that performs rear wheel steering control based on information other than the steering angle sensor output.