JPH11287608A - Steering sensor for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an accurate absolute steering angle at early stages. SOLUTION: First and second photointerrupters 8, 9 output signals indicating the amount and direction of rotation according to the rotation of a first rotor 1 which rotates integrally with a steering wheel, and a third photointerrupter 10 outputs a signal indicating the rotary position of the steering wheel during one rotation. Four notched parts 5a-5d for position signals, for indicating the rotary position, and four projecting parts 6a-6d for the position signals are formed on the first rotor 1 at unequal intervals. A second rotor 11 rotates intermittently via an intermittent gear 2 and a gear part 12 for each rotation of the steering wheel, and a variable resistor 14 is rotated accordingly. The variable resistor 14 outputs a signal indicating the ordinal revolutions of the steering wheel. An accurate absolute steering angle can be detected at early stages in accordance with these signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vehicle steering sensor used for detecting an absolute steering angle of a steering wheel.

[0002]

In recent years, in automobiles, a steering sensor has been used in a vehicle stabilit (VSC).
ycontroll) is used as a representative vehicle control system and is considered as an important signal. As a conventional steering sensor, one having the following configuration is generally used.

[0003] That is, the steering sensor is composed of a slit plate provided with a large number of slits, which is provided so as to rotate integrally with the steering wheel, and three sets of photo interrupters provided in a fixed state on the steering column. . Each photo interrupter has a configuration in which a light emitting diode and a light receiving element are opposed to each other, and a slit plate inserted between the light emitting diode and the light receiving element rotates to change between a light shielding state and a light transmitting state. A signal is output from each light receiving element based on the signal.

The first and second photo-interrupters among the three photo-interrupters are for detecting the rotation amount and the rotation direction of the steering wheel (slit plate), and the remaining third photo-interrupters are: Neutral position during one rotation of the steering wheel (reference position)
These output signals are output to the control device of the vehicle.

The range in which the steering wheel can be rotated is not limited to one rotation (360 degrees), but is, for example, two rotations to the left (720 degrees) and two rotations to the right (720 degrees) around the neutral position. 720 degrees)
± 720 degrees. However, even if there is a neutral position signal from the third photo interrupter among the output signals from the steering sensors (first to third photo interrupters), it is not known how many rotations the signal is. Therefore, an accurate absolute steering angle of the steering wheel cannot be detected only by the output signal from the steering sensor.

Therefore, conventionally, an accurate absolute steering angle (an angle based on a true neutral position) is calculated as shown in FIG.
Detection is performed according to the flow shown in FIG. That is, in a state immediately after the ignition switch is turned on, the absolute steering angle cannot be detected. The car runs,
When the neutral edge (neutral position) is detected in the third photo interrupter, the control device performs the following based on the output signal from the third photo interrupter and the output signals from the first and second photo interrupters.
The rotation amount and the rotation direction (relative steering angle) from the neutral position can be detected. However, it is not known how many rotations the neutral position is. Then, the vehicle further travels, and detects an accurate absolute steering angle based on output signals of the first to third photointerrupters and detection signals of the vehicle speed sensor and the yaw rate sensor.
The VSC is put into an operable state.

However, in the above-described conventional configuration, it is necessary to travel to some extent from when the ignition switch is turned on to when an accurate absolute steering angle is detected, and the VSC cannot be on standby until then. Therefore, there is a demand for a steering sensor that can detect an accurate absolute steering angle as soon as possible after turning on an ignition switch.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicular steering sensor capable of detecting an accurate absolute steering angle at an early stage.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a first rotating body which is integrally rotated with a steering wheel capable of rotating one or more rotations. A plurality of signal generating means provided at equal intervals on one rotator, a plurality of position signal generating means provided at unequal intervals on the first rotator, and rotation of the first rotator Based on detecting the signal generation means with
A first detection unit that outputs a signal indicating a rotation amount and a rotation direction of the steering wheel, and based on detecting the position signal generation unit with the rotation of the first rotating body,
Second detecting means for outputting a signal indicating the rotational position of the steering wheel during one rotation; and intermittently rotating the steering wheel in response to the steering wheel being rotated by a maximum amount within a operable range. A second rotating body provided to be intermittently rotated within a range of less than one rotation via a driving means, and a signal indicating the number of rotations of the steering wheel based on the rotating position of the second rotating body. And a third detecting means for outputting.

In the above configuration, when the steering wheel is rotated, the first rotating body is rotated integrally with the steering wheel, and the second rotating body is rotated intermittently. Along with the rotation of the first rotating body, a signal indicating the amount and direction of rotation of the steering wheel is output from the first detection means,
A signal indicating the rotational position of the steering wheel during one rotation is output from the second detecting means. Also, the second
A signal indicating the number of rotations of the steering wheel is output from the third detection unit based on the rotational position of the rotating body.

[0011] Here, the second rotating body is rotated by a maximum amount within a range in which the steering wheel can be operated to rotate.
Since it is configured to rotate intermittently in a range less than the rotation, the number of rotations of the steering wheel (how many rotations Number of times).

The rotation position of the steering wheel during one rotation can be detected based on the detection signal from the second detection means, and the rotation of the steering wheel can be detected based on the detection signal from the first detection means. Since the amount and rotation direction can be detected, the first and second
And an accurate absolute steering angle can be detected based on the third detection signal. Moreover, since the first rotating body is provided with a plurality of position signal generating means, the rotational position of the first rotating body during one rotation can be detected early, and the accurate absolute steering angle can be quickly determined. Can be detected.

In this case, it is preferable that the third detecting means is constituted by a variable resistor or an optical sensor.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 is a cutaway plan view of a steering sensor portion viewed from above, and FIG. 2 is a side view of the steering sensor portion viewed from the side. 1 and 2, the first rotating body 1 and the intermittent gear 2
It is mounted on the steering shaft 3 so as to rotate integrally with the steering shaft 3 in a vertically stacked state, so that it is integrally rotated with a steering wheel (not shown) attached to the steering shaft 3. Has become.

In this case, the range in which the steering wheel can be rotated includes two rotations to the left (720 degrees) and two rotations to the right (7 degrees) around the neutral position.
20 °), ± 720 °. On the outer peripheral portion of the intermittent gear 2, only one tooth portion 2a is formed.

As shown in FIG. 3, a plurality of signal slits 4 constituting a signal generating means are formed in a circular shape centering on the center of the steering shaft 3 at a position from the outer peripheral portion of the first rotating body 1 as shown in FIG. They are arranged at equal intervals.
Outside the signal slit 4, the four position signal notches 5a to 5c constituting the position signal generating means are provided.
5d and four position signal projections 6a to 6d are formed alternately at unequal intervals. In this case, the angles of the position signal notches 5a, 5b, 5c, and 5d are 40 degrees and 5 degrees, respectively.
The angles are set to 0 degree, 35 degrees, and 25 degrees, and the angles of the position signal projections 6a, 6b, 6c, and 6d are 50 degrees, respectively.
The angles are set to 45 degrees, 60 degrees, and 55 degrees.

An optical sensor mounting base 7 is provided in a fixed state corresponding to the outer peripheral portion of the first rotating body 1. This optical sensor mounting base 7 has a first detecting means
And the second photo-interrupters 8 and 9 as well as the third photo-interrupter 10 constituting the second detection means. Each of the first to third photo interrupters 8, 9, and 10 has a configuration in which a light emitting diode and a light receiving element are opposed to each other.

The first and second photointerrupters 8 and 9 are arranged such that the light emitting diode and the light receiving element sandwich a portion corresponding to the rotation locus of the signal slit 4 in the first rotator 1 from above and below. Low level when it corresponds to the signal slit 4 (in the light transmitting state),
When it does not correspond to the signal slit 4 (when light is blocked)
Output the high-level detection signals Sa and Sb (see FIG. 4). In this case, the arrangement pitch of the signal slits 4 and the first
And the arrangement of the second photointerrupters 8 and 9 is such that the resolution by the detection signals Sa and Sb is 1.125 degrees and the phase is 1
/ 4 cycle is set. Detection signals Sa, Sb of these first and second photointerrupters 8, 9
Is a signal indicating the amount and direction of rotation of the steering wheel (first rotating body 1).

Further, the third photo interrupter 10
The light emitting diode and the light receiving element are notch portions 5a to 5d for position signals and convex portions 6a to 6 for position signals in the first rotating body 1.
d is arranged so as to sandwich the portion corresponding to the rotation locus from above and below, and corresponds to the position signal cutouts 5a to 5d (in a light-transmitting state), and has a low level and a position signal protrusion 6.
A high-level detection signal Sc (see FIG. 4) is output when the signals correspond to a to 6d (in a light-shielded state). The detection signal Sc of the third photointerrupter 10 is a signal indicating the rotational position of the steering wheel (the first rotating body 1) during one rotation.

On the other hand, a portion corresponding to the outer peripheral portion of the intermittent gear 2 is provided with a second rotating body 11. A gear portion 12 is formed on a part of the outer peripheral portion of the second rotating body 11, and each time the intermittent gear 2 makes one rotation, the second rotating body 11 The part 12 meshes with the part 12 and is rotated by a predetermined angle. here,
The intermittent gear 2 and the gear portion 12 constitute an intermittent driving means for intermittently rotating the second rotating body 11. Therefore, the second rotating body 11 is set to be rotated within a range of less than one rotation in response to the steering wheel being rotated by the maximum amount (± 720 degrees) within the range in which the rotation operation is possible.

A printed board 13 is fixedly provided below the second rotating body 11 so as to face the second rotating body 11.
Is provided. The operation knob 14 a of the variable resistor 14 is rotated by the second rotating body 11. The resistance of the variable resistor 14 changes according to the rotation position of the second rotating body 11. Then, based on this, a detection signal Sd as shown in FIG. 5 is output. The detection signal Sd has a step shape and is a signal indicating the number of rotations of the steering wheel.

The first to third photo interrupters 8 to
10 and the detection signal Sd from the variable resistor 14, as shown in FIG.
5 is sent. The arithmetic unit 15 includes a microcomputer, and detects an absolute steering angle of the steering wheel based on the signals Sa, Sb, Sc, and Sd and transmits the absolute steering angle to the VSC system 16 as described later. ing.

Next, the operation of the above configuration will be described with reference to FIGS. FIG. 7 is a flowchart when the absolute steering angle is detected by the calculation unit 15, and FIG. 8 is an explanatory diagram for explaining a flow when the absolute steering angle is detected.

When the ignition switch is turned on (step S1), the calculation unit 15 detects the number of rotations X (number of rotations) of the steering wheel based on the detection signal Sd from the variable resistor 14. (Step S2). Here, the absolute steering angle cannot be detected yet.

When the steering wheel is operated to rotate as the vehicle travels, the first rotating body 1 is rotated integrally with the steering shaft 3. With the rotation of the first rotator 1, the detection signals Sa and Sb are output from the first and second photo interrupters 8 and 9, and the detection signal S is output from the third photo interrupter 10.
c is output.

Here, as shown in FIG. 4, when the arithmetic unit 15 detects the first neutral edge Ya (rising or falling of the signal) Ya in the detection signal Sc, it calculates the detection signals Sa and Sb from there. Count the number of each edge. FIG. 4 shows an example in the section of the position signal notch 5a when the first rotating body 1 rotates in the direction of arrow A in FIG. The operation unit 15 detects the detection signal S
By counting the number of edges a and Sb, the amount of rotation from the first neutral edge Ya can be detected, and the direction of rotation can be detected from the phase difference between the detection signals Sa and Sb. Then, based on detecting the second neutral edge Yb in the detection signal Sc, the calculation unit 15
An accurate steering angle A during one rotation of the steering wheel (first rotating body 1) can be detected (steps S3 and S4).

In this case, the position signal notches 5a-5d and the position signal protrusions 6a-6 constituting the position signal generating means.
Since the angle range of d is at most 60 degrees, if the steering wheel (first rotating body 1) is rotated by at most 60 degrees, an accurate steering angle A during one rotation can be detected. Become.

The arithmetic unit 15 detects the absolute steering angle B of the steering wheel based on the number of rotations X obtained in step 2 and the steering angle A during one rotation obtained in step S4. It is determined (step S5) and set as an output value (step S6). This output value is converted to a serial signal and transmitted to the VSC system 16. Thereafter, the relative steering angle α is detected based on the detection signals Sa and Sb, and the absolute steering angle B and the relative steering angle α are added and set as an output value (steps S7 and S7).
8). The VSC system 16 controls the VSC based on the absolute steering angle B + α thus obtained.

According to the above-described embodiment, the following effects can be obtained. That is, when the ignition switch is turned on, the detection signal S of the variable resistor 14 is
Based on d, the number of rotations of the steering wheel (the number of rotations) can be detected. And
Based on the detection signals Sa and Sb from the first and second photo-interrupters 8 and 9 and the detection signal Sc from the third photo-interrupter 10, the rotation amount and the rotation direction of the steering wheel can be detected. The rotation position and the steering angle A during one rotation can be detected. Therefore, each of these detection signals S
a, Sb, Sc, Sd, based on the exact absolute steering angle B
Can be detected.

In this case, the first rotating body 1 has a plurality of position signal notches 5a constituting position signal generating means.
5d and the position signal projections 6a to 6d, the rotational position of the first rotating body 1 during one rotation can be detected at an early stage, and the accurate absolute steering angle B can be detected. Can be detected early.

Further, since the arithmetic unit 15 can detect the accurate absolute steering angle B only with the detection signals Sa, Sb, Sc, and Sd from the steering sensor, the accurate absolute steering angle B can be obtained from the vehicle speed sensor and the vehicle speed sensor. There is also an advantage that the detection can be performed without using the detection signal of the yaw rate sensor.

In the first embodiment, the following configuration may be used instead of the variable resistor 14 constituting the third detecting means. That is, a magnet is provided on the lower surface of the second rotating body 11 and a magnetoresistive element is provided on the printed circuit board 13 so as to face the magnet.

In this case, the position of the magnet changes as the rotational position of the second rotating body 11 changes intermittently, and the direction of the magnetic field of the magnet with respect to the magnetoresistive element changes accordingly. Since the resistance value of the resistance element changes, the output signal of this magnetoresistance element is used as a detection signal indicating the number of rotations of the steering wheel.

FIGS. 9 to 12 show a second embodiment of the present invention. The second embodiment differs from the first embodiment in the following points. That is, as shown in FIGS. 9 and 11, two slits 20a and 20b are formed on the outer peripheral portion of the second rotating body 11 at predetermined intervals. The angular width between these two slits 20a and 20b is set to an angle at which the second rotating body 11 is rotated once by the teeth 2a of the intermittent gear 2.

An optical sensor mounting base 21 is fixed to a printed circuit board 22 at a position corresponding to the outer peripheral portion of the second rotating body 11. An optical sensor constituting the detection means, in this case, fourth and fifth photointerrupters 23 and 24 are incorporated.

The fourth and fifth photo interrupters 2
Reference numerals 3 and 24 denote light emitting diodes and light receiving elements, respectively, which are arranged so as to sandwich a portion corresponding to the rotation locus of the slits 20a and 20b in the second rotating body 1 from above and below, and correspond to the signal slits 20a and 20b. Level (when in the light transmitting state), the slits 20a, 20b
And (in a light-shielded state), it outputs high-level detection signals Se and Sf (see FIG. 12). In this case, the interval between the slits 20a and 20b and the interval between the fourth and fifth photo interrupters 23 and 24 are set to be the same.

When the steering wheel is in the first rotation, as shown in FIG. 11, the fourth photo interrupter 23 corresponds to the slit 20a, and the fifth photo interrupter 24 corresponds to both slits 20a, 20b. It is out of the position. As shown in FIG. 12, the detection signals Se and Sf in this case are low for Se and high for Sf. When the second rotating body 11 is rotated once in the direction of arrow A in FIG. 11 with the second rotation of the steering wheel, the fourth photo-interrupter 23 corresponds to the slit 20b, and the fifth Of the photo interrupter 24 correspond to the slit 20a. In this case, the detection signals Se and Sf are both low.

Similarly, as the rotation of the steering wheel becomes the third rotation, the second rotating body 11
When the first photointerrupter 23 is further rotated one time in the direction indicated by the arrow a in FIG.
Of the photo interrupter 24 correspond to the slit 20b. As the detection signals Se and Sf in this case,
Se goes high and Sf goes low. Then, with the fourth rotation of the steering wheel, when the second rotating body 11 is further rotated one time in the direction of arrow A in FIG. 11, the fourth and fifth photo interrupters 23 and 24 become Both come off the slit 20b. In this case, the detection signals Se and Sf are both high.

The arithmetic unit 15 can detect the number of rotations of the steering wheel (the number of rotations) based on the detection signals Se and Sf of the fourth and fifth photo interrupters 23 and 24. . Therefore, also in the second embodiment, the detection signals Se and Sf of the fourth and fifth photointerrupters 23 and 24 and
Detection signal S of third photo interrupter 8, 9, 10
Based on a, Sb, and Sc, an accurate absolute steering angle can be detected early as in the first embodiment.

[0040]

As is clear from the above description, according to the present invention, the following effects can be obtained. Claim 1
According to the vehicle steering sensor of the first aspect, the first detection means for outputting a signal indicating the rotation amount and the rotation direction of the steering wheel based on the rotation of the first rotating body rotated integrally with the steering wheel, Second detecting means for outputting a signal indicating the rotational position of the steering wheel during one rotation based on the rotation of the rotating body, and being provided so that the rotation of the steering wheel is intermittently rotated within a range of less than one rotation. Third detection means for outputting a signal indicating the number of rotations of the steering wheel based on the rotation position of the second rotating body, and a plurality of position signal generating means provided at the first rotating body at non-equal intervals. With this configuration, it is possible to detect an accurate absolute steering angle at an early stage.

According to the vehicle steering sensor of the second and third aspects, the number of rotations of the steering wheel can be detected satisfactorily.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a cutaway plan view of a steering sensor portion viewed from above.

FIG. 2 is a side view of the same part viewed from the side.

FIG. 3 is a plan view of a first rotating body.

FIG. 4 is a diagram showing detection signals of first to third photo interrupters;

FIG. 5 is a diagram showing a relationship between a detection signal of a variable resistor and the number of rotations of a steering wheel.

FIG. 6 is a block diagram showing an electrical configuration.

FIG. 7 is a flowchart of a calculation unit when detecting an absolute steering angle.

FIG. 8 is an explanatory diagram for explaining a flow when detecting an absolute steering angle.

FIG. 9 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 10 is a diagram corresponding to FIG. 2;

FIG. 11 is a plan view of a second rotating body.

FIG. 12 is a diagram showing detection signals of fourth and fifth photo interrupters.

FIG. 13 is an explanatory diagram for explaining a flow when detecting a conventional absolute steering angle.

[Explanation of symbols]

1 is a first rotating body, 2 is an intermittent gear (intermittent driving means), 3
Is a steering shaft, 4 is a signal slit (signal generation means), 5a to 5d are position signal notches (position signal generation means), 6a to 6d are position signal projections (position signal generation means), and 8 is 1 is a photointerrupter (first detecting means), 9 is a second photointerrupter (first detecting means), 10 is a third photointerrupter (second detecting means), 11 is a second rotating body, 12 is a gear section (intermittent driving means), 14 is a variable resistor (third detecting means), 15 is an arithmetic section, 20a and 20b are slits, and 23 is a fourth photo interrupter (third detecting means, optical sensor ), 24 are fifth photo interrupters (third detection means, optical sensors)
Is shown.

Claims (3)

[Claims] 1. A first rotating body integrally rotated with a steering wheel capable of rotating one or more rotations, and a plurality of signal generating means provided at equal intervals on the first rotating body. A plurality of position signal generating means provided on the first rotating body at unequal intervals; and a rotation of the steering wheel based on detecting the signal generating means with the rotation of the first rotating body. A first detection unit that outputs a signal indicating an amount and a rotation direction; and a rotation position during one rotation of the steering wheel, based on detecting the position signal generation unit with the rotation of the first rotator. A second detecting means for outputting a signal indicating that the steering wheel is rotated by a maximum amount within a operable range, and the rotation of the steering wheel is less than one rotation via an intermittent driving means. A second rotating body provided so as to be intermittently rotated in the range of: and a third detecting means for outputting a signal indicating the number of rotations of the steering wheel based on the rotating position of the second rotating body; A steering sensor for a vehicle, comprising: 2. A vehicle steering sensor according to claim 1, wherein said third detecting means comprises a variable resistor. 3. The vehicle steering sensor according to claim 1, wherein the third detecting means comprises an optical sensor.