JPH08193820A - Steering angle detector - Google Patents

Abstract

(57) [Abstract] [Purpose] Detects the mounting failure of the steering wheel angle sensor based on the detection information of the steering wheel angle sensor. When the detected value of the steering angle on one side by the steering wheel angle sensor 30 exceeds a first predetermined value that is set to a value larger than the value that is normally output, the slit plate 31,
The function of determining the mounting failure of the neutral position detectors such as the neutral point detection plate 34 and the photo interrupter 37, and the second detected steering angle detection value on the other side are set to values within the range that is normally output. The control device has a function of determining that the attachment state of the neutral position detector has returned to the normal state when the predetermined value is exceeded, and the slit plate 31 and the neutral point detection plate 34 are provided using only the steering wheel angle sensor 30. And photo interrupter 37
For example, it detects the mounting failure of the neutral position detector and the elimination of the mounting failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering angle detecting device equipped with a neutral position detector mounted on, for example, a four-wheel steering vehicle, and is intended to detect defective mounting of the neutral position detector.

[0002]

2. Description of the Related Art In a four-wheel steering vehicle, the steerability of the vehicle and the running stability of the vehicle are improved by steering the rear wheels according to the running state of the vehicle. The steering of the rear wheels in a four-wheel steering vehicle is controlled according to the vehicle speed, the steering angle of the steering wheel, the steering angular velocity of the steering wheel, and the like. The steering mechanism of the four-wheel steering vehicle will be described with reference to FIG. FIG. 5 shows a schematic structure of a steering system of a four-wheel steering vehicle.

As shown in the drawing, a front wheel steering mechanism 3 is provided on a steering shaft 2 of a steering wheel 1, and a hydraulic cylinder 4 of a power steering device is connected to the front wheel steering mechanism 3. The tie rods 6 of the front wheels 5L and 5R are coupled to the piston rod of the hydraulic cylinder 4, and the front wheels 5L and 5R are steered by the operation of the hydraulic cylinder 4. Rear wheel 7
A tie rod 8 is provided on each of L and 7R, and a piston rod of a rear power cylinder 9 is connected to the tie rod 8. A hydraulic pump 11 is connected to the hydraulic cylinder 4 and the rear power cylinder 9 via a branch valve 10, and a control valve 12 is provided between the rear power cylinder 9 and the branch valve 10.

The operations of the branch valve 10 and the control valve 12 are controlled by a controller 13, and the controller 13 receives a detection signal from a sensor for detecting the running condition of the vehicle. That is, the steering wheel angle sensor 14 that detects the steering wheel angle θh of the steering wheel 1 and the vehicle speed sensor 15 that detects the vehicle speed V.
A rear wheel steering angle sensor 16 for detecting the steering angle θR of the rear wheels 7L, 7R and a pressure sensor 17 for detecting the operating pressure of the power steering device are connected to the controller 13, respectively.

The controller 13 outputs an operation control signal to the branch valve 10 and the control valve 12 based on the output signals of the steering wheel angle sensor 14, the vehicle speed sensor 15, the rear wheel steering angle sensor 16 and the pressure sensor 17. The operation control of the branch valve 10 controls the supply of hydraulic oil from the hydraulic pump 11 to the hydraulic cylinder 4, and the steering of the steering wheel 1 assists the steering of the left and right front wheels 5L, 5R. Further, the supply of hydraulic oil from the branch valve 10 to the rear power cylinder 9 is controlled by the operation control of the control valve 12, and the left and right rear wheels 7L, 7R are steered corresponding to the front wheel steering. The rear wheels 7L, 7R are steered in the same direction as the front wheels 5L, 5R to improve stability, and the rear wheels 7L, 7R are momentarily steered in the opposite direction to the front wheels 5L, 5R to improve turning performance.

By the way, the steering wheel angle θh detected by the steering wheel angle sensor 14 is detected with reference to the neutral position where the front wheels 5L, 5R are in a straight traveling state. The steering wheel angle sensor 14 will be described with reference to FIG. FIG. 6 shows a perspective view of the steering wheel angle sensor 14.

As shown in the figure, the steering shaft 2
(Refer to FIG. 5)
A plurality of steering angle detecting slits 22 are formed at predetermined intervals along the circumference, and the slit plate 21 is for detecting a neutral point at a position radially offset with respect to the steering angle detecting slits 22. The slit 23 is formed. A photo interrupter 24 as a steering angle detector is provided at a position corresponding to the steering angle detecting slit 22 with the slit plate 21 interposed therebetween.
Is provided, and the steering direction and the steering angle are detected by transmitting the light of the light emitting diode of the photo interrupter 24 through the steering angle detection slit 22. Also, the slit plate 2
A photointerrupter 25 as a neutral position detector is disposed at a position corresponding to the neutral point detection slit 23 with 1 interposed therebetween, and the light of the light emitting diode of the photointerrupter 25 is transmitted to the neutral point detection slit 23. Detect the steering neutral position.

That is, the plurality of steering angle detecting slits 22 rotate as the slit plate 21 rotates, and the case where the light of the light emitting diode of the photo interrupter 24 passes through the steering angle detecting slit 22 and the case where it does not pass through is repeated. Be done.
This repetition becomes an ON / OFF signal to detect the steering wheel angle θh and the steering wheel angular velocity. Further, the photo interrupter 2 is rotated only when the neutral point detection slit 23 is rotated with the rotation of the slit plate 21 and the photo interrupter 25 reaches the position of the photo interrupter 25.
The light from the light emitting diode 5 passes through the neutral point detection slit 23, and the neutral position of the handle 1 is detected by the transmitted signal.

Generally, the handle 1 is set to rotate about three and a half rotations from one rotation end to the other rotation end, and the handle 1 is 1.75 rotations (630 deg) each from the neutral position to the left and right. It is supposed to be done. Therefore, when the handle 1 is rotated once in the left-right direction from the neutral point state, the light emitted from the light emitting diode of the photo interrupter 25 passes through the neutral point detection slit 23 and the neutral position of the handle 1 is detected.

In order to avoid such a situation, a second slit plate is rotatably provided between the photo interrupter 25 and the slit plate 21, and the neutral point detection slit 23 is provided only when the handle 1 is in the neutral point state. When the overlapping slits are provided on the second slit plate and the handle 1 is rotated one turn in the left-right direction from the neutral point state, the neutral point detection slit 23 is shielded by the second slit plate and the light emitting diode of the photo interrupter 25. Is prevented from passing through the neutral point detection slit 23 (see Japanese Utility Model Laid-Open No. 6-6163). Further, the difference in rotational speed between the left and right rear wheels 7L and 7R is detected, and when the rotational speed difference is large, the light from the light emitting diode of the photo interrupter 25 causes the neutral point detection slit 2 to be detected.
The actual neutral position of the handle 1 is detected such that the neutral position of the handle 1 is not detected even when the light passes through 3. Further, based on the information of the pressure sensor 17 for detecting the operating pressure of the power steering device, when the operating pressure is large, the steering state is set, and the light of the light emitting diode of the photo interrupter 25 passes through the neutral point detecting slit 23. Handle 1
The actual neutral position of the handle 1 is detected without detecting the neutral position of the steering wheel 1.

As a result, the actual neutral position of the steering wheel 1 is always detected, and the steering control of the rear wheels 7L and 7R in the four-wheel steering vehicle can be performed based on the accurate information of the steering wheel angle θh. .

[0012]

In the steering wheel angle sensor 14 described above, when the front wheels 5L, 5R are in the straight traveling state and the steering wheel 1 is in the neutral state, the light emitted from the light emitting diode of the photo interrupter 25 is used as the neutral point detecting slit 23. Assembly is accurate because the components need to be mounted transparently. In the steering wheel angle sensor 14 provided with the second slit plate, the number of members related to each other is large, and therefore, particularly accurate assembly is required.
However, when the handle 1 is replaced afterwards, the attachment states of the photo interrupter 25, the slit plate 21, the second slit plate, etc. are deviated, and the neutral detection position of the handle 1 changes, and the accurate handle angle θh There is a possibility that information of will not be obtained.

It is conceivable that the mounting failure of the steering wheel angle sensor 14 may be detected by some logic, the status of the mounting failure may be stored in the control device, and the control may be performed while correcting the steering wheel angle θh. , The ignition is O
If the mounting failure is canceled every time the FF is set, it is necessary to detect the mounting failure again when the ignition is turned on again. If the mounting failure is not canceled each time the ignition is turned off, the steering wheel angle sensor 14
It is necessary to detect the normal operation when it is re-installed normally.

The present invention has been made in view of the above circumstances, and provides a steering angle detection device capable of determining a mounting failure of the steering angle detector based on the detection information of the steering angle detector itself. With the goal.

[0015]

The structure of the first invention for achieving the above object is provided with a slit plate which rotates following the rotation of the steering shaft, and a predetermined interval is provided along the circumference of the slit plate. To form a plurality of steering angle detection slits, a neutral point detection slit is formed in the slit plate at a position biased in the radial direction with respect to the steering angle detection slit, and the steering angle detection slit is formed. A steering angle detector that detects a steering direction and a steering angle by transmitting light is disposed with the slit plate sandwiched therebetween, and a neutral position that detects the steering neutral position by transmitting light to the neutral point detection slit. In a steering angle detection device in which a position detector is arranged with the slit plate sandwiched between the steering angle detector and the steering angle detector, the steering angle detector detects the steering neutral position. Characterized by comprising a control device having a function of determining trims failure of the neutral position detector when the detected value of the steering angle of the side exceeds a first predetermined value.

Further, the structure of the second invention for attaining the above object is provided with a slit plate which rotates following the rotation of the steering shaft, and a plurality of slit plates are provided at predetermined intervals along the circumference of the slit plate. A slit for steering angle detection is formed, a slit for neutral point detection is formed in the slit plate at a position that is radially offset with respect to the slit for steering angle detection, and light is transmitted to the slit for steering angle detection. A steering angle detector that detects the steering direction and steering angle is disposed with the slit plate sandwiched therebetween, while a neutral position detector that detects the steering neutral position by transmitting light to the neutral point detection slit is provided. In the steering angle detecting device arranged with the slit plate sandwiched, one side steering by the steering angle detector after the steering neutral position is detected by the neutral position detector. Has a function of determining a mounting failure of the neutral position detector when the detected value of 1 exceeds a first predetermined value, and the other by the steering angle detector after determining the mounting failure of the neutral position detector. A control device having a function of determining that the mounting state of the neutral position detector is returned to normal when the detected value of the steering angle on the side exceeds a second predetermined value is provided.

In the first aspect of the invention, the first predetermined value is set to a value that exceeds the value of the steering angle output during normal steering. Further, in the second invention, the first predetermined value is set to a value that exceeds a value of a steering angle that is output during normal steering, and the second predetermined value is a steering wheel that is output during normal steering. It is characterized in that it is set in the range of the angle value. In the first and second inventions, the control device is mounted on a four-wheel steering vehicle, and the control device prohibits the control of the rear wheel steering when it is determined that the neutral position detector is not properly mounted. And a function of releasing the control prohibition of the rear wheel steering when it is determined that the mounting state of the neutral position detector is returned to normal.

[0018]

According to the first invention, the slit plate rotates following the rotation of the steering shaft, and the steering angle and the steering angle are detected by transmitting light to the steering angle detecting slit by the steering angle detector. The steering neutral position is detected by transmitting light to the neutral point detection slit by the neutral position detector. After the steering neutral position is detected, if the detected value of the steering angle on one side by the steering angle detector exceeds the first predetermined value which is the value of the steering angle that is not detected during normal steering, the neutral position is detected by the control device. The installation failure of the container is judged.

According to the second aspect of the invention, the slit plate rotates following the rotation of the steering shaft, and the steering angle and the steering angle are detected by transmitting light to the steering angle detecting slit by the steering angle detector. The steering neutral position is detected by transmitting light to the neutral point detection slit by the neutral position detector. After the steering neutral position is detected, if the detected value of the steering angle on one side by the steering angle detector exceeds the first predetermined value which is the value of the steering angle that is not detected during normal steering, the neutral position is detected by the control device. The neutral position is determined when the mounting failure of the device is determined and, after the mounting failure is determined, the detected value of the steering angle on the other side exceeds the second predetermined value in the range detected during normal steering. It is determined that the mounting state of the detector has returned to normal.

The control device is mounted on a four-wheel steering vehicle, and when the mounting failure of the neutral position detector is determined, the control of the rear wheel steering is prohibited and the mounting position of the neutral position detector is When it is determined that the steering wheel has been returned to the normal state, the control prohibition of the rear wheel steering is released.

[0021]

1 is a plan view of a main portion of a steering angle detecting device according to an embodiment of the present invention, FIG. 2 is a block diagram of a control device, FIG. The concept of the mounting state of the neutral position detector is shown. The following examples correspond to claims 2, 4, and 5 of the second invention. Further, the illustrated steering angle detecting device is applied as the steering angle detecting device of the four-wheel steering vehicle shown in FIG. 5, and the same members of the steering system of the four-wheel steering vehicle are designated by the same reference numerals and duplicated. The description is omitted.

As shown in FIG. 1, the steering angle sensor 30 as a steering angle detector includes a steering shaft 2
A slit plate 31 that rotates following (see FIG. 5) is provided, and the slit plate 31 is formed with a plurality of steering angle detection slits 32 at predetermined intervals along the circumference. Further, the slit plate 31 is formed with a neutral point detection slit 33 at a position that is offset in the radial direction with respect to the steering angle detection slit 32. A neutral point detection plate 34 is provided adjacent to the slit plate 31, and the neutral point detection plate 3 is provided.
In FIG. 4, a slit 35 is formed at a position aligned with the neutral point detection slit 33 of the slit plate 31 in the true neutral state. The neutral point detection plate 34 is rotated following a slit plate 31 at a predetermined rotation ratio by a gear mechanism (not shown).

A photo interrupter 36 as a steering angle detector is arranged at a position corresponding to the steering angle detecting slit 32 with the slit plate 31 interposed therebetween, and the steering angle detecting slit 32 is provided with a light of a light emitting diode of the photo interrupter 36. To detect the steering direction and the steering angle.
Further, a photo interrupter 37 is arranged at a position corresponding to the neutral point detection slit 33 and the slit 35 with the slit plate 31 and the neutral point detection plate 34 interposed therebetween, and when the neutral point detection slit 33 and the slit 35 are aligned with each other. The steering neutral position is detected by transmitting the light of the light emitting diode of the photo interrupter 37 to the neutral point detection slit 33 and the slit 35. That is, the neutral position detector includes the neutral point detection slit 33, the neutral point detection plate 34, and the photo interrupter 37.

In the steering wheel angle sensor 30 described above, when the plurality of steering angle detecting slits 32 rotate as the slit plate 31 rotates, and the light of the light emitting diode of the photo interrupter 36 passes through the steering angle detecting slit 32. And the case of not transmitting is repeated. This repetition becomes an ON / OFF signal to detect the steering wheel angle θh and the steering wheel angular velocity (steering direction). In addition, as the slit plate 31 rotates, the neutral point detection slit 33
And the slit 35 rotates as the neutral point detection plate 34 rotates. Only when the neutral point detection slit 33 and the slit 35 are aligned at the position of the photo interrupter 37, the light of the light emitting diode of the photo interrupter 37 passes through the neutral point detection slit 33 and the slit 35,
The neutral position of the handle 1 is detected by this transmission signal. When the handle 1 makes one rotation to the left or right from the neutral state, the neutral point detection slit 33 and the slit 35
Do not match, so the neutral point of the handle 1 will not be erroneously detected.

As shown in FIG. 2, the steering wheel angle sensor 30
The detection information of the controller 38 (see FIG.
(Corresponding to the controller 13 shown in FIG. 2), and the controller 38 controls the steering wheel angle sensor 30 and the vehicle speed sensor 1
The steering wheel angular velocity, the steering wheel angle θh, and the vehicle speed V are calculated based on the information of 5 (see FIG. 5). The rear wheel steering angle θR is calculated from the calculated calculation result, and the control valve 12
A rear wheel steering command corresponding to the rear wheel steering angle θR is output (see FIG. 5) (4WS control).

By the way, when the neutral point detection plate 34, which is the neutral position detector, or the photo interrupter 37 is defective in attachment, the controller 38 is provided with a function of determining the defective attachment. For example, as shown in FIG. 4, when the position S where the neutral point detection slit 33 and the slit 35 of the neutral point detection plate 34 are aligned is deviated to the left with respect to the neutral point C of the handle 1 by α, the controller 38 Then, it is determined that the mounting state is deviated, the command circuit of the 4WS control is cut off, the 4WS control is prohibited, and the warning light is turned on.

The function of the controller 38 for determining a mounting failure will be described in detail with reference to FIG.

In step S1, the steering wheel angle θh is calculated, and in steps S2 and S3, it is determined whether the position S deviates to the left or right, that is, the flag LFAIL and the position S when the position S deviates to the left. The state of the flag RFAIL (whether LFAIL = 1 and RFAIL = 1 or not) when is shifted to the right is determined. Since both flags are 0 in the initial state, it is determined in step S4 whether the steering wheel angle θh is within the range of values (first predetermined value) Lθh1 and Rθh1 that are not normally output. If the steering wheel angle θh is within the range of the first predetermined values Lθh1 and Rθh1, the position S is determined to be normal with respect to the neutral point C of the steering wheel 4 and 4WS.
Continue control.

As shown in FIG. 4, the position S is the handle 1
When the handle 1 is rotated rightward in this state when the handle 1 is deviated by α to the left with respect to the neutral point C, step S
In step 4, it is determined that the steering wheel angle θh exceeds the first predetermined value Rθh1 which is not normally output when the steering wheel is steered to the right. That is, since the handle 1 is rotated 1.75 rotations (630 deg) to the right from the neutral state, the first predetermined value R
By setting the value of θh1 to 650 deg, when the position S is shifted to the left with respect to the neutral point C of the steering wheel 1 by α, when the steering wheel 1 is rotated rightward, the steering wheel angle θ
It is determined that h becomes 630 deg + α (value exceeding 650 deg) and exceeds the first predetermined value Rθh1 which is not output in the normal state. In step S4, the steering wheel angle θh is the first predetermined value Rθh.
If it is determined that the value exceeds 1, the flag LFAIL when the position S is displaced to the left is set to 1 in step S5, and an attachment failure is determined. Thereafter, the 4WS control is prohibited in step S6, and the warning light is turned on in step S7.

In this state, LFAIL = 1 in step S2, so the process proceeds to step S8. In step S8, the steering wheel angle θh when the steering wheel 1 is rotated in the left direction, which is the direction opposite to the direction in which the attachment failure is determined, is set to a value set in the range that is normally output (second predetermined value). Value) Lθh
It is determined whether the number exceeds 2. That is, since the position S is left shifted with respect to the neutral point C of the steering wheel 1 when the mounting failure is not eliminated, the steering wheel angle θh when the steering wheel 1 is rotated leftward is −630 deg− (-
α) (for example, a value that does not fall below −300 deg, that is, does not exceed). Second set to the range that is output under normal conditions
By setting the predetermined value Lθh2 to −300 deg, for example, in this case, the steering wheel angle θh is set to the second value in step S8.
It is determined that the value is equal to or greater than the predetermined value Lθh2 (a value that does not fall below −300 deg), and it is determined that the mounting failure has not been resolved.

When the position S is made to coincide with the neutral point C of the handle 1 (when the mounting state of the neutral position detector is returned to normal), the handle angle θh when the handle 1 is rotated leftward is − 630deg, and in step S8 the steering wheel angle θ
A value of h exceeding the second predetermined value Lθh2 (second predetermined value Lθh
It is determined that the value is less than 2), the flag LFAIL when the position S is displaced to the left side is set to 0 in step S10, and it is determined that the mounting failure is eliminated. Then, step S11
In step S12, the 4WS control prohibition is released, and in step S12, the warning light is turned off.

When the position S is displaced to the right with respect to the neutral point C of the steering wheel 1 as opposed to FIG. 4, if the steering wheel 1 is rotated leftward in this state, the steering wheel angle θh is changed to the left side in step S4. Is less than the first predetermined value Lθh1 that is not output during normal steering (first predetermined value Lθh
It is judged to be less than 1, that is, exceeded. That is, the handle 1 is rotated 1.75 to the left from the neutral state (-630 deg).
Therefore, by setting the value of the first predetermined value Lθh1 to −650 deg, the position S is set to the steering wheel 1
When it is deviated to the right of the neutral point C (deviation amount α)
When the handle 1 is rotated to the left, the handle angle θh
Is −630 deg + (− α) (a value exceeding −650 deg) and is determined to be less than the first predetermined value Lθh1 that is not output in the normal state. When it is determined in step S4 that the steering wheel angle θh is less than the first predetermined value Lθh1, step S1
When the position S is shifted to the right in step 2, the flag RFAIL is set to 1 and the mounting failure is determined. Then, step S13
The 4WS control is prohibited in step S4 and the warning lamp is turned on in step S14.

In this state, since RFAIL = 1 in step S3, the process proceeds to step S15. In step S15, the steering wheel angle θh when the steering wheel 1 is rotated to the right, which is the direction opposite to the direction in which the attachment failure is determined, is
Value set in the range that is output during normal operation (second predetermined value)
It is determined whether or not Rθh2 is exceeded. That is, when the mounting failure is not eliminated, the position S remains displaced to the right with respect to the neutral point C of the steering wheel 1, and therefore the steering wheel angle θh when the steering wheel 1 is rotated rightward is 630 deg−α.
(For example, a value that does not exceed 300 deg). The second predetermined value Rθh2 set in the range output during normal operation is set to, for example, 300d.
By setting eg, in this case, it is determined in step S15 that the steering wheel angle θh is equal to or less than the second predetermined value Rθh2, and it is determined that the mounting failure has not been resolved.

When the position S coincides with the neutral point C of the handle 1 (when the mounting state of the neutral position detector is returned to normal), the handle angle θh when the handle 1 is rotated rightward is 630 deg. Then, in step S15, the steering wheel angle θ
Flag RFAIL when h is judged to be a value exceeding the second predetermined value Rθh2 and the position S is displaced to the right in step S16
Is set to 0 and it is determined that the mounting defect has been resolved. Thereafter, the 4WS control prohibition is released in step S13, and the warning lamp is turned off in step S14.

As described above, if the steering angle on one side is detected and the steering angle exceeds the first predetermined value, the neutral position detector is determined to be defective in mounting, and after the defective mounting is determined, When the steering angle on the other side exceeds the second predetermined value, it is determined that the attachment state of the neutral position detector has returned to normal. A function of determining that the steering angle on the other side exceeds the second predetermined value after the attachment failure is determined and determining that the attachment state of the neutral position detector is returned to normal (step S8) It is equivalent to the first invention that steps S11 and S15 to S18) are omitted.

According to the steering angle detecting device described above, the steering wheel angle sensor 30 alone is used to detect the mounting failure of the neutral position detectors such as the slit plate 31, the neutral point detecting plate 34 and the photo interrupter 37 to detect the neutral position. It is possible to prohibit the 4WS control until the device is reattached to the normal state. For this reason, it is possible to improve the reliability of the 4WS control in the four-wheel steering vehicle without providing a sensor or the like for detecting a mounting failure.

In the above embodiment, the steering wheel angle sensor 30 for determining the true neutral point using the neutral point detection plate 34 is used. However, the steering wheel angle sensor to which the present invention is applied is:
It is also possible to apply a mechanism that determines the neutral point by combining the rear wheel steering angle and the steering wheel angle θh, or a mechanism that determines the neutral point by combining the operating hydraulic pressure of the power steering and the steering wheel angle θh. Further, in the above-described embodiment, the example in which the steering angle detection device is mounted on the four-wheel steering vehicle to perform the 4WS control has been described. However, the vehicle to which the present invention is applied performs all controls based on the steering wheel angle information. It is possible to apply to the detection of the mounting failure of the neutral position detector in the vehicle.

[0038]

According to the steering angle detecting device of the first aspect of the present invention, after the steering neutral position is detected by the neutral position detector, the detected value of the steering angle on one side by the steering angle detector is a value which is output at the normal time. Since the control device is provided with a function of determining a mounting failure of the neutral position detector when the first predetermined value set to a value larger than the first predetermined value is exceeded, the detected value of the steering angle detector is set to the first value.
When the value exceeds the predetermined value, the mounting failure of the neutral position detector can be detected. As a result, it becomes possible to detect the mounting failure of the steering angle detector based on the detection information of the steering angle detector itself.

In the steering angle detecting device according to the second aspect of the present invention, after the steering neutral position is detected by the neutral position detector, the detected value of the steering angle on one side by the steering angle detector is higher than the value normally output. A function of determining a mounting failure of the neutral position detector when the first predetermined value set to a large value is exceeded, and a function of determining the mounting angle of the other side by the steering angle detector after determining the mounting failure of the neutral position detector. Controls the function of determining that the neutral position detector has returned to the normal state when the detected value of the steering angle exceeds a second predetermined value set to a value output in a normal state. Since the device is provided, when the steering angle detector detection value exceeds the first predetermined value, it is possible to detect the mounting failure of the neutral position detector, and the steering angle on the other side exceeds the second predetermined value. When the neutral position detector is installed, the mounting state is returned to normal. It is possible to detect the theft. As a result, it becomes possible to detect the mounting failure of the steering angle detector and the elimination of the mounting failure based on the detection information of the steering angle detector itself.

By mounting the steering angle detecting device of the present invention on a four-wheel steering vehicle, a mounting failure of the steering angle detector is detected based on the detection information of the steering angle detector itself, and a mounting failure occurs. During this time, it becomes possible to prohibit the control of the four-wheel steering until the steering angle detector is reattached to the normal state. As a result, it is possible to significantly improve the reliability of the four-wheel steering control in the four-wheel steering vehicle without adding a sensor member for specially detecting the mounting failure.

[Brief description of drawings]

FIG. 1 is a plan view of a main portion of a steering angle detection device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control device.

FIG. 3 is a flowchart of defective mounting detection.

FIG. 4 is a conceptual diagram of an attachment state of a neutral position detector.

FIG. 5 is a schematic configuration diagram of a steering system of a four-wheel steering vehicle.

FIG. 6 is a perspective view showing a configuration of a steering wheel angle sensor.

[Explanation of symbols]

 30 steering wheel angle sensor 31 slit plate 32 steering angle detection slit 33 neutral point detection slit 34 neutral point detection plate 35 slit 36, 37 photo interrupter 38 controller

Claims (5)

[Claims] 1. A slit plate that rotates following the rotation of a steering shaft, wherein a plurality of slits for steering angle detection are formed at predetermined intervals along the circumference of the slit plate to detect the steering angle. A steering angle detector for detecting a steering direction and a steering angle by forming a neutral point detection slit in the slit plate at a position deviated in the radial direction with respect to the steering slit and transmitting light to the steering angle detection slit. In the steering angle detecting device in which the neutral position detector for detecting the steering neutral position by transmitting light to the neutral point detection slit is arranged while sandwiching the slit plate, If the detected value of the steering angle on one side by the steering angle detector exceeds a first predetermined value after the steering neutral position is detected by the neutral position detector, the neutral position Steering angle detection apparatus characterized by comprising a control device having a function of determining the trims defect detector. 2. A steering plate is provided with a slit plate that rotates following the rotation of a steering shaft, and a plurality of steering angle detecting slits are formed along the circumference of the slit plate at predetermined intervals to detect the steering angle. A steering angle detector for detecting a steering direction and a steering angle by forming a neutral point detection slit in the slit plate at a position deviated in the radial direction with respect to the steering slit and transmitting light to the steering angle detection slit. In the steering angle detecting device in which the neutral position detector for detecting the steering neutral position by transmitting light to the neutral point detection slit is arranged while sandwiching the slit plate, If the detected value of the steering angle on one side by the steering angle detector exceeds a first predetermined value after the steering neutral position is detected by the neutral position detector, the neutral position When the steering angle detector has a function of determining a mounting failure of the detector and the steering angle detector detects the steering angle of the other side after determining the mounting failure of the neutral position detector, the steering angle detector exceeds a second predetermined value. The steering angle detecting device further comprises a control device having a function of determining that the mounting state of the neutral position detector has returned to normal. 3. The steering angle detecting device according to claim 1, wherein the first predetermined value is set to a value exceeding a value of a steering angle output during normal steering. 4. The first predetermined value is set to a value exceeding a value of a steering angle output during normal steering, and
The steering angle detection device according to claim 2, wherein the second predetermined value is set within a range of a value of a steering amount output during normal steering. 5. The control device is mounted on a four-wheel steering vehicle,
The control device has a function of prohibiting the control of the rear wheel steering when the attachment failure of the neutral position detector is determined, and the attachment state of the neutral position detector is returned to normal. The steering angle detecting device according to claim 2 or 4, wherein the steering angle detecting device has a function of canceling the control prohibition of the rear wheel steering when it is determined that the steering angle is determined to be 0.