JP2568901B2 - Rotary body origin position determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an origin position (steering neutral position) when a rotating body rotating in conjunction with steering of a steering wheel of a vehicle or the like travels straight.
The present invention relates to an apparatus for determining the origin position of a rotating body which is suitable for use in determining

[Conventional technology]

2. Description of the Related Art Conventionally, in a vehicle such as an automobile, a plurality of slits are formed at equal angular intervals (predetermined angular pitch) in a rotating disk that rotates in association with steering of a steering wheel, and two photo interrupters are adjacent to a passing position of the slits. And perform various controls linked to the steering of the steering wheel.

That is, a pulse-like electric signal (two-phase incremental signal) having the same waveform and a phase shift of about 90 ° is provided to the first and second photointerrupters in conjunction with the steering of the steering wheel.
The incremental signal is counted and the steering direction and the steering angle are detected.

Normally, since the origin position cannot be detected only by the two-phase incremental signal, an origin slit is provided on the rotating disk to detect the origin position, and the origin slit passes through the third photointerrupter. A three-bit configuration is used to obtain the origin signal, and a method is employed in which the relative position of the rotating disk from the origin position is detected by an incremental signal.

However, considering the deviation of the serration between the steering shaft and the steering wheel, the mounting tolerance between the steering shaft and the steering sensor, the poor adjustment of the wheel alignment, and the like, the mounting error is as large as several tens of degrees in the worst case. For this reason, in order to obtain the origin signal, the angle width of the origin slit where the rotating disk is provided is usually enlarged, and even if there is an assembly error of several tens of degrees, as long as the vehicle is traveling straight, A signal can be obtained.

As a result, there arises a problem that the origin position cannot be specified only by the presence or absence of the origin signal, and in order to solve such a problem, as disclosed in JP-A-61-28811. A steering position detecting device has been proposed. That is, the steering position detection device is provided on a steering member that is rotated by a steering operation, detects a steering angle, outputs a steering angle signal, and detects a steering position corresponding to an actual steering angle zero. Neutral zone detecting means for detecting a predetermined steering range (origin range in the present invention) and outputting a steering neutral zone signal, and calculating an average value of the steering angle signal when the steering neutral zone signal is detected. ,
And a neutral position calculating means for outputting the average value as a neutral position signal.By using such a steering position detecting device, regardless of the maintenance condition of the vehicle or the occupant status of the vehicle, the vehicle position can be controlled. The steering neutral position in the straight traveling state can be detected.

[Problems to be solved by the invention]

However, according to such a steering position detection device, the average value during the detection of the steering neutral zone signal is calculated and output as the neutral position signal. There was a problem that it took time to obtain.

In addition, in order to calculate the average value of the steering angle signal when the steering neutral zone signal is detected, a weighted moving average calculation is performed to calculate the average value. The computation has complicated the circuit configuration.

[Means for solving the problem]

The present invention has been made in order to solve such a problem, and a slit zone provided at a predetermined angular pitch on an outer peripheral surface thereof and an origin zone provided at an angular width wider than two angular pitches of the slit zone. A rotating body that rotates clockwise and counterclockwise in conjunction with an external operation; rotation position detecting means that detects a rotation angle position of the rotating body based on passage of the rotating body through a slit zone; Origin range detecting means for detecting the origin range of the rotating body based on the passage of the origin zone of the body; and, while the origin range is detected by the origin range detecting means, the rotational angle position detected by the rotational position detecting means. The origin zone is divided into a plurality of sub-zones based on the sub-zone, and a sub-zone which has continuously contributed to the detection of the origin range for at least a predetermined time is determined as the origin position. Origin position determining means, and when updating the determination result of the origin position, a sub-zone adjacent to the sub-zone direction which has continuously contributed to the detection of the origin range for the predetermined time or longer is determined as the origin position. It is.

Further, among the divided sub-zones, the vehicle further comprises origin position determining means for determining the sub-zone that has continuously contributed to the detection of the origin range while traveling for a predetermined distance or more as the origin position, and when updating the determination result of the origin position, The sub-zone adjacent in the sub-zone direction that has continuously contributed to the detection of the origin range while traveling for a predetermined distance or more is determined as the origin position.

[Action]

Therefore, according to the present invention, when the origin position before the determination and the origin position after the determination are not subzones adjacent to each other, it is possible to gradually approach the true origin position for each subzone while shifting the origin position one by one. It becomes possible.

〔Example〕

Hereinafter, an apparatus for determining the origin position of a rotating body according to the present invention will be described in detail.

FIG. 1 is a block diagram showing an embodiment of the origin position determining device. In the figure, reference numeral 5 denotes an input which receives a pulse-like electric signal transmitted from a rotational position detecting sensor (steering angle sensor) 100 (FIG. 2) and transmits a processing signal (an up signal and a down signal) in accordance with steering of the steering wheel. / DOWN
The switching circuit 6 is an UP / DOWN counter that receives a processing signal sent from the UP / DOWN switching circuit 5 as an input.

The steering angle sensor 100 includes a rotating disk (rotating body) 1 that rotates in association with steering of a steering wheel, and photointerrupters 2 to 4 having a light emitting element and a light receiving element. Slits (slit zones) 1a of the same shape are formed at equal angular intervals (predetermined angular pitch P) on the outer peripheral surface. The photo interrupters 2 and 3 are arranged adjacent to each other at a position where the slit 1a passes.
Fig. 3 (a) by the passage of the slit 1a accompanying the rotation of
And (b), a pulse-like electric signal having the same waveform alternately having the "1" level and the "0" level is generated. That is, when the steering wheel is now rotated clockwise (rightward rotation in FIG. 2) from the steering state as shown in FIG. 2, an electric signal in the positive direction centering on the point N is counterclockwise. When rotated, an electric signal is generated in the negative direction about the point N. The electric signal generated in the photo-interrupter 2 has a phase 90 ° ahead of the electric signal generated in the photo-interrupter 3, and the electric signal generated at the origin position (steering neutral position) of the rotating disk 1 which is ideal in design, At the point N shown in the figure, the electric signal generated in the photo interrupter 2 is at the falling or rising timing at which the level changes from "1" level to "0" level or from "0" level to "1" level. The electric signal generated at 3 is "0"
You are in a level state. And this photo interrupter 2
And 3 are input to the UP / DOWN switching circuit 5.

On the other hand, a slit 1b as an origin zone is independently provided at a predetermined rotation angle position on the outer peripheral surface of the rotating disk 1, and the passage of the slit 1b is detected by the photo interrupter 4. That is, the rotational position where the slit 1b faces the photo interrupter 4 is defined as the origin range of the rotating disk 1.
(Origin range detecting means) detects the angular width of the origin range, that is, the angular width α of the slit 1b, to determine the deviation of the serration between the steering shaft and the steering wheel, the mounting tolerance between the steering shaft and the steering sensor, and the poor alignment of the wheel alignment. It is set to be larger than the worst case of the considered assembly error. In the present embodiment, the angle width α of the slit 1b is set to 60 °, and a value of 50 ° is experimentally obtained as a worst case of the assembling error in the investigation of the inventor. Is set to 60 °, a "1" level origin range detection signal (FIG. 3 (c)) can be obtained as an electric signal transmitted by the photointerrupter 4 whenever the vehicle is traveling straight. . Then, the "1" level origin range detection signal is transmitted through its terminal 101 in FIG.
The signal is supplied to one end of an AND gate 7 and a first input terminal of a three-input OR gate 9 via an inverter 8.

Here, the photo interrupter 4 is located at the center of the angular width α of the slit 1b at the origin position which is ideal in design of the rotating disk 1, that is, at the point N shown in FIG. In the present embodiment, the slit 1b
Is set to be slightly wider than three times the angle pitch P of the slit 1a (three angle pitches).

On the other hand, the UP / DOWN switching circuit 5 processes the input pulsed electric signal and sends out up signals and down signals corresponding to the right steering amount and the left steering amount of the steering wheel from its output terminals 5a and 5b. The UP / DOWN counter 6 counts up or down the count value by the number of input up signals or down signals. That is, the count value of the UP / DOWN counter 6 is basically set to zero with reference to the origin position which is ideal in design of the rotating disk 1, and the count value of the photo-interrupter 2 is increased by right steering of the steering wheel. The output is sequentially increased every falling edge of the output. Further, the count value is sequentially decreased at each rising edge of the output of the photo interrupter 2 by the left steering of the steering wheel. That is, in FIG. 3, if the steering wheel is rotated rightward starting from the point N, the count value of the UP / DOWN counter 6 at the point a is sequentially increased to +1 and at the point b to +2. If it is rotated from the point to the left, the count value of the UP / DOWN counter 6 at the point c becomes −1,
At the point d, it sequentially goes down to -2. this
The rotation angle position (including the rotation direction) of the rotating disk 1, that is, the steering angle (including the steering direction) can be known from the count value of the UP / DOWN counter 6. In this embodiment, the photo interrupters 2 and 3, the UP / DOWN switching circuit 5, and the UP / DOWN counter 6 constitute a steering angle detecting means (rotational position detecting means).

The count value of the UP / DOWN counter 6 is given to the decoder 10. The decoder 10 selects an output terminal at a position corresponding to the provided count value, and sets its level to "0" or "1". ”Is configured to control an external device that operates in conjunction with steering wheel steering, for example, a cornering lamp system. In this figure, the output terminal 10a of the decoder 10
However, when the count value of the UP / DOWN counter 6 is ± 0, the output level of the output terminal 10a is “1”.

An output terminal generated at the output terminal 10a of the decoder 10 is provided as an “D” input of the D flip-flop 13 via one end of the AND gate 11 and the inverter 12, and the “D” input of the D flip-flop 13 The "Q" output is input to one ends of AND gates 14 and 15. The "Q" and "Q bar" outputs of the D flip-flop 16 are applied to the other ends of the AND gates 14 and 15, and the "0" level is output via the UP / DOWN counter 6 when the count value is positive. , The “Q _D ” output which becomes “1” level when negative is applied as the “D” input of the D flip-flop 16. The outputs of the AND gates 14 and 15 are connected to the first input terminal 17 of the encoder 17.
a and a second input terminal 17b, and a third input terminal 17c of the encoder 17 is provided with an AND gate 1
Outputs of 4 and 15 are input via an OR gate 18 and an inverter 25.

On the other hand, the other end of the AND gate 7 is supplied with a clock signal sent from the reference clock generator 20. The counter performs a count-up operation based on the clock signal input through the AND gate 7. A "1" level overflow signal (CARRY signal) is transmitted from 21. The "1" level CARRY signal is supplied as "CP" input of D flip-flops 13 and 16, and
It is provided to the RS flip-flop 22 as its "S" input. Then, the "Q" output of the RS flip-flop 22 is given to the other end of the AND gate 11, and prompted by a "1" level output signal input through the AND gate 11 to cause the one-shot multivibrator ( (Hereinafter, this is simply called a one-shot.) A one-shot signal is transmitted from 23, and this one-shot signal is given to the UP / DOWN counter 6 as its load signal. When this load signal is input to the UP / DOWN counter 6, "1" is input to the input terminal 17a of the encoder 17.
When the level signal is set, the count value of the UP / DOWN counter 6 is set to +1 based on the output state of the encoder 17 at this time.
When a load signal is input to the UP / DOWN counter 6 and a signal of “1” level is set to the input terminal 17 b of the encoder 17, based on the output state of the encoder 17 at this time, UP / DOWN is performed. The count value of the counter 6 is set to −1, and the encoder 17
If a "1" level signal is set to the input terminal 17c, the count value of the UP / DOWN counter 6 is set to ± 0.

The one-shot 24 operates at the falling edge of the one-shot signal transmitted by the one-shot 23, and the RS flip-flop 22 is reset by the one-shot signal transmitted by the one-shot 24. It has become. An up signal and a down signal sent from the UP / DOWN switching circuit 5 are input to the second and third input terminals of the three-input OR gate 9, and are input through the OR gate 9. The one-shot signal is sent from the one-shot 25 in response to the "1" level signal, and the one-shot signal is supplied to the counter 21 as a reset signal.

 Next, the operation of the device configured as described above will be described.

Now, assuming that the automobile is traveling straight, and the rotating disk 1 is located at the original origin position which is ideal in design as shown in FIG. While the "1" level origin range detection signal is being input, the count value of the UP / DOWN counter 6 is much longer in the case where ± 0 is continued than in the case where +1 and -1 are continued. That is, while the “1” level origin range detection signal is being input via the terminal 101,
The clock signal transmitted from the reference clock generator 20 passes through the AND gate 7 and is supplied to the counter 21. When a predetermined time elapses while the count value of the UP / DOWN counter 6 is maintained at ± 0, that is, when a predetermined time elapses without sending an up signal or a down signal from the UP / DOWN switching circuit 5, the supplied clock signal , The counter 21 sends a "1" level CARRY signal from the counter 21. This "1" level CARRY signal is input to the "CP" inputs of the D flip-flops 13 and 16 and the "RS flip-flop 22". S "input. At this time, UP / DOW
Since the count value of the N counter 6 maintains ± 0, the level of the output terminal 10a of the decoder 10 is “1”, and therefore the “Q” output of the D flip-flop 13 has its “CP” input set to “1”. Level, the "0" level is maintained, the outputs of the AND gates 14 and 15 maintain the "0" level state, and the encoder 17 receives a "1" level signal at its input terminal 17c. Will continue to be. That is, when the RS flip-flop 22 is set by the “1” level CARRY signal sent from the counter 21, the “1” level “Q” output passes through the AND gate 11. This allows one shot 23
The load signal is supplied to the UP / DOWN counter 6, and based on the output state of the encoder 17 at this time, that is, the setting state of the “1” level signal to the input terminal 17c, U
The count value in the P / DOWN counter 6 is set to ± 0. In this case, the count value of the UP / DOWN counter 6 is already ± 0, and based on such operation, the count value of the UP / DOWN counter 6 keeps ± 0 at the straight steering position.

That is, by appropriately setting the count-up number until the input clock signal to the counter 21 overflows, the counter is not counted for a short time in the UP / DOWN counter 6 in which the count value continues +1 and -1. The count operation of the clock signal at 21 is set to UP / D
The reset is performed based on the up signal and the down signal via the OWN switching circuit 5.

On the other hand, when the rotating disk 1 is deviated from the origin position which is ideal in design due to the assembling error, the correcting operation which is a feature of the present embodiment is promptly performed as follows. Therefore, the external device can be controlled in conjunction with the steering of the steering wheel without any trouble.

That is, when the rotating disk 1 is at the origin position which is ideal in design, the Z1 (d) shown in FIG.
Assuming that the range up to the point is the origin zone in the slit 1b, within a region from the point c to the point a which divides the origin zone (hereinafter, this region is referred to as a first sub-zone), while traveling straight, UP / The count value of the DOWN counter 6 is ±
0 continues for a longer time. However, in the case where the rotating disk 1 is deviated from an ideal origin position in design due to the assembling error, the count value of the UP / DOWN counter 6 becomes +1 or -1 during straight running. The time to continue is longer. That is, a that divides the origin zone
UP / DOW in a region from point to point b (hereinafter, this region is referred to as a second sub-zone) or in a region from point c to point d (hereinafter, this region is referred to as a third sub-zone)
The time during which the count value of the N counter 6 continues +1 or -1 is much longer than the time during which ± 0 continues in the first sub-zone.

If the time during which the count value of the UP / DOWN counter 6 continues +1 in the second sub-zone increases, the UP / DOWN
When the count value of the counter 6 is +1, that is, when the second sub-zone is detected from the three sub-zones, the counter 21 sends a "1" level CARRY signal. At this time, the output terminal of the decoder 10
The level of 10a is "0", so that the "Q" output of the D flip-flop 13 is at "1" level. Also, D
The "Q" output of flip-flop 16 remains at the "1" level, which causes the
A "1" level signal is set to the 17 input terminals 17b. On the other hand, the CARRY of “1” level from the counter 21
When the signal is transmitted, the "Q" output of the RS flip-flop 22 becomes "1" level. The "1" level "Q" output of the RS flip-flop 22 is
When the level of the output terminal 10a becomes "1", that is, UP /
When the count value of the DOWN counter 6 is returned to ± 0 due to the steering of the steering wheel, it passes through the AND gate 11, and the “1” level “Q” output passing through the AND gate 11 causes the output to go through the one-shot 23. A load signal is supplied to the UP / DOWN counter 6. The input of the load signal causes the count value of the UP / DOWN counter 6 to change from ± 0 to −1 based on the output state of the encoder 17 at this time, that is, the setting state of the “1” level signal to the input terminal 17b. And the setting will be changed. In other words, the count value of the UP / DOWN counter 6 becomes −1 in the first sub-zone and ± 0 in the second sub-zone. The correction of the value is performed promptly.

Also, if the time during which the count value of the UP / DOWN counter 6 continues to be -1 in the third sub-zone becomes longer,
When the count value of the / DOWN counter 6 is -1, that is, when the third sub-zone of the three sub-zones is detected, the counter 21 outputs a "1" level CARRY signal. Become. At this time, the level of the output terminal 10a of the decoder 10 is "0", so that the "Q" output of the D flip-flop 13 is at the "1" level. The "Q" output of the D flip-flop 16 also becomes "1" level.
A "1" level signal is set to the 17 input terminals 17a. On the other hand, the CARRY of “1” level from the counter 21
When the signal is transmitted, the "Q" output of the RS flip-flop 22 becomes "1" level. The “Q” output of the “1” level of the RS flip-flop 22 indicates that the count value of the UP / DOWN counter 6 is ± 0 with the steering of the steering wheel.
At the time of returning to the above, the signal passes through the AND gate 11, and the "1" level "Q" output passing through the AND gate 11 provides a load signal to the UP / DOWN counter 6 via the one-shot 23. . When the load signal is input, the count value of the UP / DOWN counter 6 is set to ± 0 based on the output state of the encoder 17 at this time, that is, the setting state of the “1” level signal to the input terminal 17a.
The setting is changed from +1 to +1. That is, UP / D
The count value in the OWN counter 6 becomes +1 in the first sub-zone and ± 0 in the third sub-zone.
The correction of the count value in the / DOWN counter 6 is promptly performed.

Furthermore, in the present embodiment, in consideration of a special traveling state such as traveling on a road surface that is greatly inclined left and right, in this case, the update of the determination result of the origin position is not suddenly performed between distant subzones. For this purpose, the following correction of the count value in the UP / DOWN counter 6 with one cushion is performed.

That is, for example, assuming that the determination result that the origin position is present in the third sub-zone is obtained, the count value of the UP / DOWN counter 6 is ± 0 in the third sub-zone in accordance with the steering operation, and + In the first subzone
1, +2 in the second sub-zone. In such a state, based on the above-mentioned special traveling state, the UP / DOWN counter 6
If it is assumed that the time during which the count value continues to be +2 becomes longer, the count value of the UP / DOWN counter 6 becomes +
When the number is 2, that is, when the second sub-zone is detected from the three sub-zones, the CARRY signal of the "1" level is transmitted from the counter 21. That is, a "1" level signal is set at the input terminal 17b of the encoder 17 based on the "1" level CARRY signal, and the count value of the UP / DOWN counter 6 is returned to ± 0 with the steering of the steering wheel. At this point, the count value of the UP / DOWN counter 6 is changed from ± 0 to −1 based on the output state of the encoder 17 at this time, that is, the setting state of the “1” level signal to the input terminal 17b. Become like That is, the count value of the UP / DOWN counter 6 is -1 in the third sub-zone, ± 0 in the first sub-zone, and +1 in the second sub-zone.

As a result, during the period in which the "1" level origin range detection signal is generated, the time during which the count value of the UP / DOWN counter 6 continues +1 becomes longer, and the count value of the UP / DOWN counter 6 is +1. At the time, that is, at the time when the second sub-zone of the three sub-zones is detected,
The counter 21 sends a "1" level CARRY signal. That is, based on the “1” level CARRY signal, “1” is continuously input to the input terminal 17b of the encoder 17.
When the level signal is set and the count value of the UP / DOWN counter 6 is returned to ± 0 due to the steering of the steering wheel, the output state of the encoder 17 at this time, that is, “1” to the input terminal 17b thereof The count value of the UP / DOWN counter 6 is ±
The setting is changed from 0 to -1. In other words, UP
The count value of the / DOWN counter 6 is -2 in the third sub-zone, -1 in the first sub-zone, and ± 0 in the second sub-zone. Thereafter, during the generation period of the “1” level origin range detection signal, the time during which the count value of the UP / DOWN counter 6 continues ± 0 becomes longer, and the count value of the UP / DOWN counter 6 becomes ± 0. At the time, that is, at the time when the second sub-zone among the three sub-zones is detected, the CARRY signal of the "1" level is transmitted from the counter 21. In this manner, the determination result of the origin position is determined by the first. The third sub-zone is updated via the first sub-zone to the second sub-zone.

That is, when the origin position is updated at once from the third sub-zone to the second sub-zone, the variable position of the irradiation direction of the headlight based on the count value of the UP / DOWN counter 6 suddenly changes. As a result, the driver is confused. On the other hand, in the present embodiment, when the origin position before the determination and the origin position after the determination are not sub zones adjacent to each other, the update of the origin position is performed in one cushion, so that the cornering lamp system is used. A sudden change in the irradiation direction of the headlight does not occur.

In the present embodiment, the clock signal transmitted from the reference clock generator 20 is input to the counter 21 via the AND gate 7, but instead of the clock signal transmitted from the reference clock generator 20, You may comprise so that the pulse signal (distance signal) according to a distance may be input. That is, when the traveling distance exceeds a predetermined value based on the distance signal passing through the AND gate 7, the counter 21 sends a "1" level CARRY signal, and the UP / DOWN counter 6 receives the CARRY signal based on the CARRY signal. May be corrected. That is, a configuration may be adopted in which the sub-zone which has continuously contributed to the detection of the origin range among the three sub-zones while traveling for a predetermined distance or more is determined as the origin position, and the count value of the UP / DOWN counter 6 is corrected. Good. With this configuration, the origin position can be determined more quickly as the traveling speed increases.

In the above-described embodiment, when the origin zone is divided into a plurality of sub-zones, the division is performed with the minimum resolution of the steering angle sensor. However, the setting of these sub-zones is not necessarily the minimum resolution of the steering angle sensor. Not,
It may be an integral multiple of this minimum resolution. When the sub-zone is set to an integral multiple of the minimum resolution, each sub-zone may have a portion overlapping each other.

Further, in the above-described embodiment, the angle width α of the slit 1b is set to be slightly wider than the three angle pitch of the slit 1a. However, the angle width α may be at least wider than the two angle pitch of the slit 1a. By doing so, the origin zone can be divided into a plurality of sub-zones based on the steering angle position detected by the steering angle sensor, and it is possible to accurately determine the origin position within the origin zone whose width is enlarged. Become.

Further, in the above-described embodiment, the origin zone is divided into three. However, the origin zone may be divided more finely. By continuously determining the sub-zones adjacent to the sub-zone direction that contributed to the detection of the origin range as the temporary origin position while traveling, the origin positions are shifted one by one to the adjacent sub-zones, and each sub-zone is shifted one by one. It goes without saying that it can be made to approach the true origin position.

Further, in the above-described embodiment, the determination of the steering neutral position in the vehicle has been described as an example. However, the present invention is not limited to the vehicle alone, and the determination of the origin positions of various rotating bodies that rotate in conjunction with an external operation is performed. The present invention is suitable for application to various types of control, and various controls can be performed based on the determined origin position, and its utility value is extremely high. Further, in the embodiment, the apparatus for determining the origin position of the rotating body is constituted by a specific circuit as hardware, but it is needless to say that it can be realized by a shift technique using a microcomputer or the like. .

As an example showing the basics of the present embodiment, there is Japanese Patent Application No. 63-78530 (rotational body origin position determination device) by the present applicant. In the case of this device, the origin range of each of the divided sub-zones is determined. A large number of memory areas are required to store the accumulated time that contributed to the detection. On the other hand, in the case of the origin position determining apparatus as in this embodiment, the memory area can be saved, the circuit configuration can be simplified, and the cost can be reduced, as compared with the method of storing the integrated time. It becomes possible.

〔The invention's effect〕

As described above, according to the rotating body origin position determining apparatus according to the present invention, the slit zone provided on the outer peripheral surface at a predetermined angular pitch and the origin provided with an angular width wider than two angular pitches of the slit zone are provided. A rotating body having a zone and rotating in a clockwise and counterclockwise direction in conjunction with an external operation; a rotating position detecting means for detecting a rotating angle position of the rotating body based on passage of the rotating body through a slit zone;
Origin range detecting means for detecting an origin range of the rotating body based on passage of the rotating body through the origin zone; and a rotation angle detected by the rotational position detecting means while the origin range is detected by the origin range detecting means. Origin position determining means for dividing the origin zone into a plurality of sub-zones based on a position, and determining, from the divided sub-zones, a sub-zone which has continued to detect an origin range continuously for a predetermined time or more as an origin position; When updating the position determination result, the sub-zone adjacent to the sub-zone direction which has contributed to the detection of the origin range continuously for the predetermined time or longer is determined as the origin position. The origin zone position determining means for continuously determining the sub-zone that has contributed to the detection of the origin range as the origin position. When updating the determination result of, the sub-zone adjacent in the sub-zone direction that has contributed to the detection of the origin range is continuously determined as the origin position while the vehicle travels for the predetermined distance or more. If the origin positions of the sub-zones are not adjacent to each other, it is possible to gradually approach the true origin position for each sub-zone while shifting the origin position one by one. When rotated, the steering neutral position can be accurately and quickly determined with a simple circuit configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a device for determining the origin of a rotating body according to the present invention, FIG. 2 is a schematic diagram showing a steering angle sensor used in the device, and FIG. FIG. 4 is an output waveform diagram of FIG. 1 ... rotating disk, 1a ... slit, 1b ... slit, 2,
3,4 …… photo interrupter, 5 …… UP / DOWN switching circuit,
6 UP / DOWN counter, 7 AND gate, 9
3 input OR gate, 10 decoder, 13, 16 D flip-flop, 17 encoder, 20 reference clock generator, 21 counter, 22 RS flip-flop, 23, 25 one-shot.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Soichi Tajima 500 Kitawaki, Shimizu City, Shizuoka Prefecture Inside the Koito Manufacturing Shizuoka Plant (72) Inventor Kazuki Takahashi 500 Kitawaki, Shimizu City, Shizuoka Prefecture Koito Manufacturing Shizuoka Co., Ltd. In-plant (72) Inventor Shinzo Yokoyama 500 Kitawaki, Shimizu-shi, Shizuoka Prefecture Koito Manufacturing Co., Ltd.Shizuoka Plant (72) Inventor Akihiro Matsumoto 500, Kitawaki, Shimizu-shi, Shizuoka Prefecture Koito Manufacturing Shizuoka Plant (72) Inventor Takashi Kurita 500 Kitawaki, Shimizu City, Shizuoka Pref. Koito Manufacturing Co., Ltd. Shizuoka Plant (56) References JP-A-61-28811 (JP, A) Real-life Sho 62-158302 (JP, U)

Claims (2)

(57) [Claims] 1. A timepiece having a slit zone provided at a predetermined angular pitch on an outer peripheral surface thereof and an origin zone provided at an angular width wider than two angular pitches of the slit zone. A rotating body that rotates in a counterclockwise direction, rotation position detecting means that detects a rotation angle position of the rotating body based on passage of the rotating body through a slit zone, and a rotating body that rotates based on the passage of the rotating body through an origin zone. Origin range detection means for detecting the origin range, and while the origin range is detected by the origin range detection means, divides the origin zone into a plurality of sub-zones based on the rotation angle position detected by the rotation position detection means, Origin position determining means for determining, as the origin position, a sub-zone which has continuously contributed to detection of the origin range for a predetermined time or more among the divided sub-zones; Determination when updating the result, the rotation of the origin position determination apparatus characterized by adjacent subzone was to determine the position of origin contributed to subzone direction detection of the origin range continuously the predetermined time or more. 2. A timepiece having a slit zone provided at a predetermined angular pitch on an outer peripheral surface thereof and an origin zone provided at an angular width wider than the two angular pitches of the slit zone. A rotating body that rotates in a counterclockwise direction, rotation position detecting means that detects a rotation angle position of the rotating body based on passage of the rotating body through a slit zone, and a rotating body that rotates based on the passage of the rotating body through an origin zone. Origin range detection means for detecting the origin range, and while the origin range is detected by the origin range detection means, divides the origin zone into a plurality of sub-zones based on the rotation angle position detected by the rotation position detection means, Origin position determination means for determining the sub-zone which has contributed to the detection of the origin range continuously while traveling for a predetermined distance or more in the divided sub-zones as the origin position. When the determination result of the origin position is updated, a sub-zone adjacent in the sub-zone direction that has continuously contributed to detection of the origin range while traveling for the predetermined distance or more is determined as the origin position. Origin position determination device.