JP2005147794A - Steering angle detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering angle detection device allowing the changing of an installation position and retrofitting to a vehicle without it preinstalled. <P>SOLUTION: The device comprises a light-emitting device 2a, a light-receiving device 2b which receives light from the light-emitting device 2a, and a central processing unit 6 which detects and processes received light. A part which rotates during steering is irradiated with light, and its reflected light is measured to detect a steering angle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention belongs to the technical field of steering angle detection means for detecting the steering angle of a vehicle.

A conventional steering angle detecting device is known in which a driven gear with a magnet meshing with a main gear fixed to a steering column shaft is provided on a steering pad, and a change in a magnetic field accompanying rotation of the driven gear is detected by an MR sensor. (For example, refer to Patent Document 1).
JP 2002-213944 A

  However, in the above prior art, the main gear is fixed to the steering shaft, the driven gear and the MR sensor are installed in the steering pad, and the assembly to the vehicle is premised on the manufacturing stage. Therefore, it is difficult to retrofit the steering member, and there is a problem in that an in-vehicle device that requires steering angle information cannot be mounted on the vehicle.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a steering angle detection device that facilitates retrofitting to a steering member and enables mounting of on-vehicle equipment.

  In order to achieve the above-described object, in the steering angle detection device of the present invention, a first steering member, a second steering member that rotates relative to the first steering member during steering, and the first steering member are provided on the first steering member. A light emitting unit that irradiates light to the member, a detected portion that reflects the light output from the light emitting unit, provided to the second steering member so as to face the light emitting unit, and a light detecting unit that are provided integrally with the light emitting unit. A light receiving unit that receives light reflected by the light receiving unit, a movement amount detecting unit that detects a movement amount of the detected unit according to the state of the light input to the light receiving unit, and a detected movement amount of the detected unit And a steering angle detector for detecting the steering angle of the steering.

  In the present invention, the light emitting portion and the light receiving portion are integrally provided on the first steering member, and the detected portion provided on the second member does not require wiring such as a power supply line or a signal line. Assembling work is easy. Therefore, by using the present invention, it is possible to mount an in-vehicle device that requires steering angle information even if the vehicle is not equipped with a steering angle detection device.

  The best mode for carrying out the present invention will be described below based on the first embodiment.

First, the configuration will be described.
FIG. 1 is a side view illustrating an installation example of a steering angle detection device. A steering angle detection device 1 according to the first embodiment includes a detection unit 2 and a detected unit 4.

  The detection unit 2 is installed on the upper surface side of the steering column cover (first steering member) 5 located on the vehicle front side of the steering wheel 3. The detected portion 4 has the same rotating shaft as that of the steering wheel 3 and is fixed to the wheel bottom portion 3a that is the bottom surface of the steering wheel 3 on the steering column cover (second steering member) 5 side. 4 a faces the detection unit 2.

  FIG. 2 is a perspective view of the detection unit 2, and the detection unit 2 is provided with a light emitting element (light emitting unit) 2a and a light receiving lens (light receiving unit) 2b facing the same surface of the casing 2f. The light emitting element 2a irradiates the detected portion 4 with light. In the first embodiment, an LED is used. The light receiving lens 2 b inputs the light of the light emitting element 2 a reflected by the detected portion 4 into the detecting portion 2.

  The detection unit 2 detects the relative movement amount of the detected unit 4 with respect to the detection unit 2 in accordance with the state of light input from the light receiving lens 2b. The detected relative movement amount is output as a relative movement amount data signal to the central processing unit (steering angle detection unit) 6 via the power source / signal harness 7. The central processing unit 6 detects the steering angle of the steering wheel based on the input relative movement amount data, and outputs a steering angle signal to an in-vehicle device (not shown).

FIG. 3 is a front view of the detected portion 4.
The detected portion 4 is formed in an annular shape with a hole in the center, and a neutral position specifying slit 4b is formed. The surface of the portion to be detected 4 is provided so as to reflect the light emitted from the light emitting element 2a, and angle detection lines 4c are engraved at a constant angle. The angle detection line 4c is provided so as not to reflect light as compared with other surfaces.

  Both the slit 4b and the angle detection line 4c are provided on the outer periphery 4a to be detected, and are set to reflect the light from the light emitting element 2a to the light receiving lens 2b when facing the detection unit 2 during steering.

FIG. 4 is a cross-sectional view showing the inside of the casing 2 f in the detection unit 2.
An optical image sensor 2c and a circuit board (movement amount detection unit) 2e are provided inside the casing 2f, and a light emitting element 2a, a light receiving lens 2b, and an optical image sensor 2c are mounted on the circuit board 2e. Yes.

  The optical image sensor 2c is installed between the light receiving lens 2b and the circuit board 2e, detects the light collected by the light receiving lens 2b, and outputs it to the circuit board 2e. A light receiving plate 2d is installed on the light receiving surface of the optical image sensor 2c.

FIG. 5 is a control block diagram of the steering angle detection device 1.
The light output from the light emitting element 2a is reflected by the surface of the detected portion 4, condensed on the light receiving lens 2b, and input to the optical image sensor 2c. As described above, the intensity of the reflected light accompanying the rotation of the detected portion 4 is input at every fixed rotation angle.

  The optical image sensor 2c detects the amount of movement of the detected portion 4 based on the input light. This movement amount is not an absolute movement amount from the neutral position, but a relative movement amount from the movement start position. The detected relative movement amount data is input to the central processing unit 6.

  The central processing unit 6 includes a movement amount sampling processing unit 6a, a zero point detection processing unit 6b, a movement amount accumulation processing unit 6c, a conversion constant unit 6d, a movement amount → steering angle conversion unit 6e, and steering angle averaging. And a processing unit 6f.

  The movement amount sampling processing unit 6a samples the relative movement amount data, and outputs the sampling result to the zero point detection processing unit 6b and the movement amount accumulation processing unit 6c. Sampling refers to digitizing an analog signal through a sampler, a sampling card, a scanner, or the like at a constant interval of time or coordinates, and converting it to a numerical value with a finite number of digits. By this processing, the relative movement amount data that is an analog signal is converted to enable digital processing.

  The zero point detection processing unit 6b executes zero point detection processing for detecting the neutral position of the detected unit 4 based on the sampled data, and outputs the zero point detection result to the movement amount accumulation processing unit 6c.

  The movement amount accumulation processing unit 6c calculates an absolute movement amount that is an accumulated movement amount from the zero point based on the detected zero point and the sampled data, and calculates the calculation result as a movement amount → steering angle conversion processing unit. Output to 6f.

  The conversion constant unit 6d stores a conversion constant for converting the movement amount into the steering angle.

  The movement amount → steering angle conversion processing unit 6e executes a process of converting the calculated absolute movement amount into a steering angle with reference to the conversion constant stored in the conversion constant unit 6d, and averages the conversion result to the steering angle. The data is output to the processing unit 6f.

  The steering angle averaging processing unit 6f averages the obtained absolute steering angle and outputs a steering angle signal to various applications of the in-vehicle device.

Next, the operation will be described.
[Steering angle detection]
When the steering wheel 3 is neutral, the light from the light emitting element 2 a passes through the slit 4 b of the detected portion 4. When the driver starts steering, the steering wheel 3 rotates, and the detected portion 4 also rotates in conjunction with this.

  Along with the rotation of the steering wheel 3, the light that has passed through the slit 4b at the neutral position is reflected by the surface of the rotating detected portion 4, condensed by the light receiving lens 2b, and passed through the light receiving plate 2d to the optical image sensor 2c. Entered.

  With the rotation of the detected part 4, the reflection surface of the light from the light emitting element 2 a rotates on the detected part 4 and crosses the angle detection line 4 c provided on the surface of the detected part 4.

  On the angle detection line 4c, the light is less likely to be reflected than the other surfaces of the other detection target parts 4, so that the reflected light is weakened when the light from the light emitting element 2a crosses the angle detection line 4c. In this way, the intensity of the reflected light changes each time the light from the light emitting element 2 a crosses the angle detection line 4 c, which is detected by the optical image sensor 2 c, and the central processing unit 6 rotates the rotation angle of the detected portion 4. And the steering angle of the steering wheel 3 is measured.

[Assembling to steering]
FIG. 6 is a perspective view showing a method of assembling the steering angle detection device 1 to the steering. At the time of assembly, the steering wheel 3 is first removed from the steering column shaft 8.

  Subsequently, the casing 2f of the detection unit 2 is fixed to the center of the upper surface of the steering column cover 5, and the light emitting element 2a and the light receiving lens 2b are fixed toward the steering wheel 3 side. As a fixing method, any method such as a bolt, an adhesive, and a seal may be used.

  Next, the detected portion 4 is sandwiched between the steering column cover 5 and the steering wheel 3 with the neutral position being matched, and the steering wheel 3 is attached to the steering column shaft 8.

Next, the effect will be described.
In the steering angle detection device 1 according to the first embodiment, the following effects can be obtained.

  (1) After fixing the casing 2f of the detection unit 2 to the steering column cover 5, the mounting to the steering is completed simply by fixing the detected portion 4 between the steering column cover 5 and the steering wheel 3. Assembly work can be performed easily. Therefore, even a vehicle that is not equipped with a steering angle detection device can be mounted with an in-vehicle device that requires steering angle information.

  (2) Since the detection unit 2 detects the amount of movement of the detected unit 4 at the time of steering in a non-contact manner, there is no need for the wiring of a power source, a signal, etc. on the detected unit 4 side, and the degree of freedom of the mounting position Is expensive. Moreover, even when retrofitted to a vehicle, the beauty around the steering wheel is not impaired.

  (3) Since the amount of movement of the detected portion 4 is detected using the optical image sensor 2c, the reflected light can be accurately measured. Therefore, high resolution can be obtained without being affected by the processing accuracy.

  (4) Since the light emitting element 2a, the light receiving lens 2b, and the optical image sensor 2c are mounted on the circuit board 6e provided in the casing 2f, the assembling work can be performed with a few steps (effect corresponding to claim 2). ).

  (5) Since the detection unit 2 is fixed to the upper surface of the steering column cover 5 and the detected unit 4 is fixed to the wheel bottom 3a of the steering wheel 3, the power source / signal harness 7 for connecting the detection unit 2 and the central processing unit 6 However, it does not interfere with driving by moving during steering (effect corresponding to claim 2).

(Other examples)
Although the best mode for carrying out the present invention has been described based on the first embodiment, the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the present invention. Any changes in the design of the range are included in the present invention.

  For example, in the first embodiment, the angle detection line 4c is provided on the surface of the detected part 4. However, by increasing the resolution of the optical image sensor, the surface of the detected part 4 is provided without providing the angle detection line 4c. The angle may be detected by scanning.

  Further, in the first embodiment, the detection unit 2 is installed on the upper surface of the steering column cover 5, and the disc-shaped detected unit 4 is installed in the gap between the steering wheel 3 and the steering column cover 5, but FIG. As shown to a) and (b), the to-be-detected part 9 is made into a hollow cylinder, the outer peripheral part is made into the to-be-detected surface 9a, and the detecting part 20 is installed in the steering column cover 5 facing this to-be-detected surface 9a. May be.

  Further, as shown in FIG. 8A, the wheel bottom 3a itself is used as a detected portion, the detecting portion 30 is installed in the steering column cover 5, and a hole 5a is formed on the side surface of the steering column cover 5 on the steering wheel 3 side. And rotation of the wheel bottom 3a may be detected.

  Further, as shown in FIG. 8B, the steering angle detection device 1 may be provided in the steering column cover 5, and the outer peripheral surface 8a of the steering column shaft 8 may be used as the detected portion.

  Further, as shown in FIG. 8 (c), the steering angle detection device 1 for detecting the rotation of the wheel bottom 3a from the hole 5a has a bolt hole 12a on the detection surface side as shown in FIG. 8 (c). It will be fixed using the formed flange 12.

It is a side view which shows the example of installation of a steering angle detection apparatus. It is a perspective view of a steering angle detection device. It is a front view of a detected part. It is sectional drawing which shows the inside of a casing in a detection part. It is a control block diagram of a steering angle detection device. It is a perspective view which shows the assembly | attachment method to the steering of a steering angle detection apparatus. It is another example of installation of a steering angle detection apparatus. It is another example of installation of a steering angle detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering angle detection apparatus 2 Detection part 2a Light emitting element 2b Light receiving lens 2c Optical image sensor 2d Light receiving plate 2e Circuit board 2f Casing 3 Steering wheel 3a Wheel bottom part 4 Detected part 4a Detected part outer periphery 4b Slit 4c Angle detection line 5 Steering Column cover 6 Central processing unit 6a Movement amount sampling processing unit 6b Zero point detection processing unit 6c Movement amount accumulation processing unit 6d Conversion constant unit 6e Movement amount → steering angle conversion processing unit 6f Steering angle averaging processing unit 7 Harness 8 Steering column shaft

Claims (3)

A first steering member;
A second steering member that rotates relative to the first steering member during steering;
A light emitting unit provided on the first steering member and irradiating light on the second steering member;
A second detection member provided on the second steering member so as to face the light emitting unit, and a detected unit that reflects light output from the light emitting unit;
A light receiving unit that is provided integrally with the light emitting unit and that receives light reflected by the detected unit;
In accordance with the state of the light input to the light receiving unit, a movement amount detection unit that detects the movement amount of the detected unit;
A steering angle detector that detects a steering angle of the steering based on the detected movement amount of the detected part;
A steering angle detection device comprising: In the steering angle detection device according to claim 1,
A circuit board provided with the movement amount detection unit is provided,
A steering angle detecting device, wherein the light emitting unit and the light receiving unit are mounted on a substrate. In the steering angle detection device according to claim 1 or 2,
The light emitting part and the light receiving part are fixed to the outside of the steering column cover,
A steering angle detecting device, wherein the detected portion is formed in an annular shape and fixed to a steering pad.

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