JPH0758180B2 - Origin position determination device for rotating body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used to determine the origin position (steering neutral position) of a rotating body that rotates in conjunction with steering of a vehicle or the like when traveling straight. The present invention relates to a suitable origin position determining apparatus for a rotating body.

[Conventional technology]

Conventionally, in vehicles such as automobiles, a plurality of slits are provided at equal angular intervals (predetermined angular pitch) on a rotating disk that rotates in conjunction with steering of a steering wheel, and two photo interrupters are adjacent to each other at a position where the slits pass. Various controls that are linked to the steering of the steering wheel are arranged.

That is, in association with steering of the steering wheel, the first and second
The photo interrupter generates a pulse-shaped electric signal (two-phase incremental signal) having the same waveform and a phase difference of approximately 90 °, and counts the incremental signal to detect the steering direction and the steering angle. .

Normally, the origin position cannot be detected only with the above-mentioned two-phase incremental signals. Therefore, an origin slit is provided on the rotating disk to detect the origin position, and the origin slit passes through the third photo interrupter. The origin signal is obtained to have a 3-bit configuration, and a method of detecting the relative position of the rotating disk from the origin position with an incremental signal is adopted.

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, and the misalignment of the wheel alignment, the assembly error is several tens of degrees in the worst case. Therefore, normally, in order to obtain the origin signal, the angular width of the origin slit provided on the rotating disc is expanded, and even if there is a mounting error of several tens of degrees, as long as the vehicle is traveling straight,
It is assumed that the origin signal can be obtained.

As a result, there is 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 detecting device is provided on a steering member that is rotated by a steering operation, detects a steering angle, outputs a steering angle signal, and a steering position corresponding to the actual steering angle zero point. , A predetermined steering range (origin range referred to in the present invention) is detected, and a neutral zone detection means for leaving the steering neutral zone signal and an average value of the steering angle signal when the steering neutral zone signal is detected are calculated. However, it is provided with a neutral position calculating means for outputting this average value as a neutral position signal, by using such a steering position detecting device, regardless of the vehicle maintenance situation or the occupant situation to the vehicle, It is supposed that the steering neutral position can be detected when the vehicle is traveling straight.

[Problems to be Solved by the Invention]

However, according to such a steering position detecting device,
Since the average value is calculated and output as the neutral position signal while the steering neutral zone signal is detected, there is a problem that it takes time to obtain a new neutral position signal to be updated.

Further, 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 calculation makes the circuit configuration complicated.

[Means for Solving the Problems]

The present invention has been made to solve such a problem, and a slit zone provided at a predetermined angular pitch on the 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 clockwise or counterclockwise direction in conjunction with an external operation, a rotational position detecting means for detecting a rotational angular position of the rotating body based on the passage of a slit zone of the rotating body, and this rotating body. 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 the rotation angle position detected by the rotation position detecting means while the origin range is being detected by the origin range detecting means. Based on this, the origin zone is divided into a plurality of sub-zones, and the time contributing to the detection of the origin range of each of the divided sub-zones is added up. The subzones having the largest is obtained a determining origin position determining means as the origin position.

[Action]

Therefore, according to the present invention, in the origin zone, the subzone in which the integrated time contributing to the detection of the origin range is maximized within the predetermined time is defined as the origin position.

〔Example〕

Hereinafter, the origin position determining apparatus for 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 FIG. 5, reference numeral 5 is an UP that receives a pulse-shaped electric signal sent from a rotational position detection sensor (steering angle sensor) 100 (FIG. 2) and sends processing signals (up signal and down signal) according to steering of a steering wheel. A / DOWN switching circuit 6 is an UP / DOWN counter which receives the processing signal sent from the UP / DOWN switching circuit 5.

The steering angle sensor 100 includes a rotating disc 1 that rotates in association with steering of a steering wheel and photo interrupters 2 to 4 having light emitting elements and light receiving elements. The slits 1a having the same shape are opened at equal angular intervals (predetermined angular pitch P). Photointerrupters 2 and 3 are arranged adjacent to each other at a position where the slit 1a passes, and the photointerrupters 2 and 3 pass through the slit 1a as the rotary disc 1 rotates, so that the photointerrupters 2 and 3 shown in FIG. ) And (b), pulsed electric signals of the same waveform with alternating "1" level and "0" level are generated. That is, now
When the steering wheel is rotated clockwise (clockwise in FIG. 2) from the steering state as shown in FIG. 2, an electric signal in the positive direction centered on the point N is rotated N counterclockwise. An electric signal is generated in the negative direction around the point. The electrical signal generated in the photo interrupter 2 has a phase advanced by 90 ° with respect to the electrical signal generated in the photo interrupter 3, and the rotating disk 1 which is ideal in design is shown.
At the origin position (steering neutral position), that is, at the N point shown in FIG. 3, the electric signal generated in the photo interrupter 2 changes from “1” level to “0” level or from “0” level to “1” level. The electric signal generated in the photo interrupter 3 is in the "0" level state at the falling or rising timing which changes. Then, the electric signals sent from the photo interrupters 2 and 3 are UP / DOW.
It is input to the N switching circuit 5.

On the other hand, at the predetermined rotation angle position of the outer peripheral surface of the rotary disc 1,
Independently, a slit 1b as an origin zone is provided, and the passage of this slit 1b is detected by the photo interrupter 4. That is, the rotation position where the slit 1b faces the photo interrupter 4 is set to the rotation disk 1
The angle width of this origin range, that is, the angle width α of the slit 1b, is taken into consideration in consideration of 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 misalignment of the wheel alignment. It is set to be larger than the worst case of assembly error. In this embodiment, the angular width α of the slit 1b is set to 60 °, and in the investigation by the inventor, a value of 54 ° was experimentally obtained as the worst case of the above assembly error. If 60 is set to 60 °, it is possible to obtain the origin range detection signal (FIG. 3 (c)) of "1" level as the electric signal sent by the photo interrupter 4 whenever the vehicle is traveling straight ahead. . The origin range detection signal of the "1" level is supplied to the three-input AND gate 14, the AND gate 39, the "A" input terminal of the decoder 44 and the inverter 41 in FIG. It is to be input to the AND gate 40. Here, the photo interrupter 4
Is the ideal origin position for the design of the rotating disk 1,
That is, at point N shown in FIG. 3, the angular width α of the slit 1b is
It is located in the center of. Further, in this embodiment, the angular width α of the slit 1b is set to be slightly wider than three times the angular pitch P of the slit 1a (3 angular pitch).

On the other hand, the UP / DOWN switching circuit 5 processes the input pulse-shaped electric signal and sends out the number of up signals and down signals corresponding to the right steering amount and the left steering amount of the steering wheel, The UP / DOWN counter 6 counts up or down 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 ideal origin position in the design of the rotary disk 1, and the count value of the photo interrupter 2 is determined by steering the steering wheel to the right. It goes up at every falling edge of the output. Further, the left steering of the steering wheel causes the count value to sequentially decrease at each falling edge of the output of the photo interrupter 2. That is, in FIG.
If the handle is rotated to the right starting from point N,
At the point, the count value of UP / DOWN counter 6 is +
It goes up to 1 at 1 and b to +2 at point b. If you rotate it from point N to the left, UP / D at point c
The count value of the OWN counter 6 sequentially decreases to -1 and to -2 at the point d. And UP / D
The count value in the OWN counter 6 is also input to the decoder 7 and the digital comparators 8 to 10. The decoder 7 selects an output terminal (not shown) at a position corresponding to the input count value, The level is set to "0" or "1", and it is configured to control an external device that operates in conjunction with steering of the steering wheel, such as a cornering lamp system.

A predetermined comparison reference value is set in each of the comparators 8 to 10. Here, the comparison reference value and the UP / DOWN counter 6 are set.
Is compared with the count value input via. That is, +1 is set as the count value in the UP / DOWN counter 6 in the comparator 8 as the vertex zone right end reference value, and in the comparator 10,
As the count value of the UP / DOWN counter 6, -1 is set as the origin zone left end reference value. In the comparator 9, ± 0 is set as the count value in the UP / DOWN counter 6 as the origin zone center reference value,
The count value input via the UP / DOWN counter 6 is ±
When it is 0, the output level of the comparator 9 is "1".
Has become. When the count value input via the UP / DOWN counter 6 is +1 the output level of the comparator 8 is "1", and when the count value input via the UP / DOWN counter 6 is -1, The output level of the comparator 10 is "1". The "1" level signal sent from the comparators 8 to 10 is input to one end of the AND gates 11 to 13, and the output of the AND gate 14 is output to the other ends of the AND gates 11 to 13. Is to be entered. As described above, the origin range detection signal is input to the first input end of the AND gate 14 via the photo interrupter 4 shown in FIG. 2, but to the second input end. The clock signal sent from the sampling clock generator 15 is input, and the processed signal is input to the third input end via the vehicle speed detection circuit 16. The vehicle speed detection circuit 16 includes resistors R1 to R8,
It is composed of capacitors C1 and C2, diode D1, transistors Q1 and Q2, and comparator CP, and when the vehicle speed is generated based on the vehicle speed signal input through terminal 102, the output of comparator CP to AND gate 14 is output. "1"
It has become a level. That is, when the vehicle is stopped, the output of the comparator CP is at "0" level.

On the other hand, the outputs of the AND gates 11 to 13 are input to the counters 17 to 19, and the count value of each counter is the one sent by the one-shot multivibrator (hereinafter, simply referred to as one-shot) 20. It is adapted to be taken into the atch circuits 21 to 23 at each falling edge of the shot signal. And the latch circuits 21, 22 and 2
The count value taken in 3 is input to predetermined input terminals of the digital comparators 24 to 26. That is, assuming that the count values taken into the latch circuits 21, 22 and 23 are α, β and γ, respectively, the count value α sent from the latch circuit 21 is sent to the non-inverting input terminals of the comparators 24 and 26 by the latch circuit 22. The count value β to be input is input to the inverting input terminal of the comparator 24 and the non-inverting input terminal of the comparator 25, and the count value γ output from the latch circuit 23 is input to the inverting input terminals of the comparators 25 and 26. It has become so. The outputs of the comparators 24 to 26 are input to the input terminals 27a to 27c of the decoder 27.
Selects a predetermined terminal among the output terminals 27d to 27i based on the combination of signals input to the input terminals 27a to 27c, and sets the output level of the terminal to "1".
The truth table of the decoder 27 is shown separately in Table 1 and Table 2.

That is, the selected position of the output terminal at the "1" level is determined as shown in Table 2 according to the magnitude relationship between the count values α, β and γ captured in the latch circuits 21, 22 and 23. The signals sent from the output terminals 27d to 27i are input to one ends of the NAND gates 28 to 33. The output of the AND gate 13 is branched to the other ends of the NAND gates 28 and 29. The output of the AND gate 12 is branched and input to the other ends of the NAND gates 30 and 33, and the output of the AND gate 11 is branched and input to the other ends of the NAND gates 31 and 32. It has become so. Then, the outputs of the NAND gates 28 to 33 are input to the one-shot 34, and the one-shot 34 operates at the falling edge of the input signal.
The one-shot signal sent from the OR gate 35 passes through the OR gate 35 and becomes a reset signal for returning the count value of the UP / DOWN counter 6 to ± 0. The one-shot signal sent from the one-shot 34 is also branched and input to the latch circuits 21 to 23, and the latch data in the latch circuits 21 to 23 is also reset.

In addition, the one-shot 36 is activated based on the one-shot signal sent by the one-shot 20, and the one-shot signal sent by the one-shot 36 is counted.
The reset signal returns the count value in 17 to 19 to zero. The one-shot 20 operates based on the overflow signal (CARRY signal) sent from the counter 37, and repeatedly sends the one-shot signal to the latch circuits 21 to 23 every predetermined time. The counter 37 includes a comparator CP in the vehicle speed detection circuit 16.
While the comparison output of is at "1" level, the clock signal sent from the sampling block generator 15 is
It is supposed to be input via 38. The count operation of the counter 37 is set by the one-shot signal sent by the one-shot 36.

On the other hand, to the other ends of the AND gates 39 and 40, the comparison output sent from the comparator 42 is input, and the comparator 42 applies a predetermined voltage to the terminal 103 at the same time when the power is turned on, The comparison output is immediately set to the "1" level, and the comparison output is returned to the "0" level with a delay of a predetermined time based on the increase in the charging level of the capacitor C3. The output of the AND gate 39 is input to the other end of the OR gate 35, the output of the OR gate 40 is input to the set terminal of the flip-flop 43, and the Q output of the flip-flop 43 is input to the “B” of the decoder 44. It is supposed to be input to the input end. UP / DOW at "C" and "D" inputs of decoder 44
The down signal and the up signal are input through the N switching circuit 5, and the decoder 44 has "0", "0", and "0" at its input terminals "D", "C", "B", and "A". "1",
When the "1" or "1" signal is input, its output terminal
44a level is "1", "1", "0",
When the "1" or "1" signal is input, its output terminal
The level of 44b is set to "1". Then, when a signal of "1" level is sent from the output terminal 44a of the decoder 44, this signal is UP / D'ed via the OR gate 45.
The load signal is input to the OWN counter 6 and the decoder 4
Based on the output state of 4, the count value of the UP / DOWN counter 6 is set to +1 via the encoder 46. When a signal of "1" level is transmitted from the output terminal 44b of the decoder 444, this signal is input as a load signal to the UP / DOWN counter 6 via the OR gate 45, and the encoder 46 based on the output state of the decoder 44.
Via the UP / DOWN counter 6
It is set to 1. In addition, OR gate
The load signal output from 45 is also input to the one-shot 47, and the one-shot 47 operates at the falling edge of this input load signal, and the one-shot signal transmitted by this one-shot 47. By this, the flip-flop 43 is reset.

Next, the operation of the apparatus thus configured will be described. That is, assuming that the automobile is now traveling straight ahead and the rotary disc 1 is located at the true original steering position at the original design ideal position as shown in FIG.
While the origin range detection signal of “1” level is input via 101, the period in which the count value of the UP / DOWN counter 6 is ± 0 becomes long. That is, UP / DOWN
The count value of the counter 6 is input to the decoder 7 and also to the comparators 8 to 10 at the same time, and is compared with each reference value in the comparators 8 to 10. UP / D
When the count value of the OWN counter 6 is +1, the comparator 8 sends a signal of "1" level, and UP / DOWN
When the count value of the counter 6 is -1, the comparator 10 sends out a signal of "1" level. Also UP / D
When the count value of the OWN counter 6 is ± 0, the comparator 9 sends a signal of "1" level. And
Based on the "1" level signal sent from the comparators 8 to 10, while the "1" level origin range detection signal is being input through the terminal 101, the sampling clock generator 15 passing through the AND gate 14 The clock signal passes through the AND gates 11 to 13 and is input to the counters 17 to 19. That is, when the count value in the UP / DOWN counter 6 is +1 the count value in the counter 17 is integrated and increases, and when the count value in the UP / DOWN counter 6 is -1, the count value in counter 19 is integrated. Up. When the count value of the UP / DOWN counter 6 is ± 0, the count value of the counter 18 is integrated and increased. Then, the count value of each counter is taken in by the latch circuits 21 to 23 at the falling edge of the one-shot signal sent by the one-shot 20. On the other hand, the counters 17 to 19 after the count value has been fetched are reset by the one-shot signal sent by the one-shot 36, the count value is returned to zero, and the count of the clock signal to be input next is prepared. . That is, the counters 17 to 19 count the clock signals input within a predetermined time (in this embodiment, 1 minute) determined by the output cycle of the CARRY signal sent by the counter 37, and latch the clock signals. The circuits 21 to 23 have counters 17 to 19 within this predetermined time.
The count value counted in is retained.

Thus, the count values (α, β and γ) fetched by the latch circuits 21, 22 and 23 are compared by using the comparators 24 to 26. In this case, since the count value in the UP / DOWN counter 6 is ± 0 for a long period of time, the count value β held by the latch circuit 22 of the latch circuits 21 to 23 becomes the maximum, and the decoder 27 causes the latch circuit
Depending on the magnitude relation of the count values at 21, 22 and 23, a signal of "1" level is transmitted from the output terminal 27f or 27i. In such a state, if the AND gate 12 passes the clock signal sent from the sampling clock generator 15, the other ends of the NAND gates 30 and 33 become "1" level, and the signal sent to the one-shot 34 falls, UP. A reset signal is input to the / DOWN counter 6 via the OR gate 35, and the count value is ± 0.
Becomes That is, the UP / DOWN counter 6 is reset when the clock signal is input to the counter 18 that performs the maximum counting within the predetermined time period via the AND gate 12. In this case, the count value of the UP / DOWN counter 6 is already ± 0, so that the count value of the UP / DOWN counter 6 continues to maintain ± 0.

The above-described operation has been described assuming that the rotating disc 1 is located at the ideal origin position in the design at the true straight-ahead steering position when the vehicle travels straight, but the rotating disc 1 is designed due to the assembly error. In the case of deviation from the ideal origin position, etc., the correction operation, which is a feature of this embodiment, is promptly performed as follows, and the external device can be controlled in conjunction with the steering wheel without any trouble. You will get it.

That is, when the rotating disk 1 is at the origin position that is ideal in design, when the range from the Z1 (d) point to the Z2 (b) point shown in FIG. Within the area from point c to point a that divides this origin zone (hereinafter, this area is referred to as the first subzone), while the vehicle is traveling straight, the count value of the UP / DOWN counter 6 is ±
The time to maintain 0 becomes long. However, when the rotating disc 1 is displaced from the ideal origin position in design due to the assembly error, the count value of the UP / DOWN counter 6 is +1 or -1 during straight traveling. Will be maintained for a longer period. That is, within the area from point a to point b (hereinafter, this area is referred to as a second subzone) dividing the origin zone, or from area c to d (hereinafter, this area is referred to as a third subzone). ), The integration time for the count value of the UP / DOWN counter 6 to become +1 or -1 becomes longer.

If the integration time for which the count value of the UP / DOWN counter 6 becomes +1 in the second subzone becomes long, the latch circuit
The count value α held by the latch circuits 21 of 21 to 23 becomes the maximum, and the "1" level signal is transmitted from the output terminals 27a and 27h of the decoder 27. Then, when the clock signal passes through the AND gate 11, that is, when the second subzone among the three subzones is detected, the other ends of the NAND gates 31 and 32 become "1" level, and UP / DOWN. The counter 6 is reset and the count value is set to ± 0. That is, the second subzone is quickly determined as the origin position, and the count value in the UP / DOWN counter 6 is corrected.

Further, when the integration time in which the count value in the UP / DOWN counter 6 becomes -1 in the third subzone becomes long, the count value γ held by the latch circuit 23 of the latch circuits 21 to 23 becomes the maximum, and the output of the decoder 27 is output. A signal of "1" level is transmitted from the terminals 27d and 27e. And
When the clock signal passes through the AND gate 13, that is, when the third subzone among the three subzones is detected, the other ends of the NAND gates 28 and 29 become the "1" level, and the UP / DOWN counter 6 Is reset and the count value is set to ± 0. That is, the third subzone is quickly determined to be the origin position, and the count value in the UP / DOWN counter 6 is corrected.

When the vehicle is stopped, the output of the comparator CP in the vehicle speed detection circuit 16 becomes "0" level, so that the clock signal from the sampling clock generator 15 cannot pass through the AND gate 14 and the origin position. In that first
The time that contributes to the transmission of the origin range of the third subzone is
The counters 17 to 19 do not integrate.

Immediately after the power supply to this device is turned on, the comparison output sent from the comparator 42 continues to be "1" for a predetermined time.
When the power is turned on when the “1” level origin range detection signal is input through the terminal 101, the comparison output of the “1” level sent from the comparator 42 outputs the AND gate 39. Pass and UP via ORGATE 35
The count value of the / DOWN counter 6 is forcibly set to ± 0, whereby the subzone detected immediately after power-on is set as the initial origin position.

When the power is turned on when the “1” level origin range detection signal is not input via the terminal 101, the “1” level signal is output via the inverter 41 to the AND gate 40.
The flip-flop 43 is brought into the set state by the "1" level comparison output sent from the comparator 42 which is input to the AND gate 40 and is sent to the AND gate 40. As a result, the "1" level Q output of the flip-flop 43 is set to the "B" input terminal of the decoder 44. Then, when the steering wheel is subsequently operated to input the "1" level origin range detection signal through the terminal 101, the "1" level origin range detection signal is supplied to the decoder 44 as "A".
It will be set at the input end. Now, assuming that a "1" level origin range detection signal is generated by the right rotation of the rotating disk 1 associated with the right steering, the "1" level up signal from the UP / DOWN switching circuit 5 associated with this right steering. The decoder of 44
Depending on the setting of the “D” input terminal of the
The output terminal 44b level becomes "1" level and UP / DOWN
The count value of the counter 6 is set to -1, and the third subzone of the three subzones is set as the initial origin position. Further, if it is assumed that a "1" level origin range detection signal is generated by the left rotation of the rotating disk 1 associated with left steering, a "1" level down signal from the UP / DOWN switching circuit 5 associated with this left steering. Depending on the setting of the “C” input terminal of the decoder 44, the output terminal of the decoder 44 at this point
44a level becomes "1" level and UP / DOWN counter 6
Is set to +1 and the second subzone of the three subzones is set as the initial origin position.

In this embodiment, when the origin zone is divided into a plurality of sub-zones, the division is performed by the minimum resolution of the steering angle sensor, but the setting of these sub-zones does not necessarily have to be the minimum resolution of the steering angle sensor. Alternatively, it may be an integral multiple of this minimum resolution. Further, when the sub-zones are set to an integral multiple of the minimum resolution, each sub-zone may have a portion overlapping each other.

Further, in this embodiment, the angular width α of the slit 1b is set to be slightly wider than the three angular pitch of the slit 1a, but the angular width may be wider than at least the two angular 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 the origin position can be accurately determined within the origin zone whose width is expanded. . As an example showing the basics of the present embodiment, Japanese Patent Application No. 60-298018 (Japanese Patent Publication No. 4-33374) filed by the present applicant.
(There is a method for determining the center position of the rotating body), but in this method, the angular width of the slit for detecting the origin position is narrow,
The purpose of this embodiment cannot be achieved.

In addition, in the present embodiment, the determination of the steering neutral position in the vehicle has been described as an example, but the present invention is not limited to the vehicle, and it is possible to determine the apex position of various rotating bodies that rotate in conjunction with an external operation. It is suitable to apply, it is possible to perform various controls based on the determined origin position,
Its utility value is extremely high. Further, in the above embodiment, the origin position determining device for the rotating body is constituted by a concrete circuit in hardware, but it goes without saying that it can be realized by a software technique using a microcomputer or the like. Yes.

〔The invention's effect〕

As described above, according to the origin position determining apparatus for a rotating body according to the present invention, the slit zones provided on the outer peripheral surface thereof at a predetermined angle pitch and the origin provided at a wide angular width of two angular pitches of the slit zones. A rotating body having a zone that rotates in a clockwise or counterclockwise direction in conjunction with an external operation; a rotational position detecting means for detecting a rotational angular position of the rotating body based on passage of a slit zone of the rotating body; Origin range detecting means for detecting an origin range of the rotating body based on passage of the origin zone of the rotating body, and a rotational angle position detected by the rotating position detecting means while the origin range is being detected by the origin range detecting means. Based on the above, the origin zone is divided into a plurality of subzones, and the time contributing to the detection of the origin range of each of the divided subzones is integrated. In the origin zone, it is possible to set the origin position to the subzone in which the integrated time that has contributed to the detection of the origin range is the maximum within a predetermined time. For example, when the rotating body is rotated in association with the steering operation of the vehicle, the steering neutral position can be accurately and quickly determined with a simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a rotary body origin position determining device according to the present invention, FIG. 2 is a schematic diagram showing a steering angle sensor used in this device, and FIG. 3 is this steering angle sensor. 3 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, 8-10 …… Comparator, 15
…… Sampling clock generator, 17 to 19 …… Counter, 21 to 23 …… Latch circuit, 24 to 26 …… Comparator,
27 …… decoder, 37 …… counter.

Claims (1)

[Claims] 1. A timepiece having a slit zone provided at a predetermined angular pitch on the outer peripheral surface thereof and an origin zone provided at an angular width wider than the two angular pitches of the slit zone, in cooperation with an external operation. A rotating body that rotates counterclockwise, a rotational position detecting means that detects a rotational angular position of the rotating body based on passage of a slit zone of the rotating body, and a rotating body of the rotating body based on passage of an origin zone of the rotating body. Origin range detection means for detecting the origin range, and while the origin range is being detected by this origin range detection means, the origin zone is divided into a plurality of subzones based on the rotation angle position detected by the rotation position detection means, The time that contributed to the detection of the origin range of each of the divided subzones is integrated, and the subzone in which this integrated time is the maximum within the predetermined time is determined as the origin position. Origin position determination device of the rotating body formed by a point position determining means.