JPH0245268A - Method for judging original position of rotary body - Google Patents

Abstract

PURPOSE:To improve the accuracy of judgement by dividing an original point zone into a plurality of sub-zones on the basis of the rotational angle position to be detected by a detection means, and judging a sub-zone having contributed for detecting the area of original point continuously over a specified time as the original point position. CONSTITUTION:A steering angle sensor 100 is composed of a rotary disc 1 interlocked with the steering of a handle, photointerruptors (photoelectric sensors) 2 - 4. The photoelectric sensors 2, 3 and 4 are, respectively, closely disposed at slits 1a formed on the outer circumferential face of the disc 1 at an equal angle distance and at a slit 1b formed as an original point zone at an angle width over 2 angle degree pitch larger than that of the slit 1a. When the area of original point is detected, the original point zone is divided into a plurality of sub-zones on the basis of the rotational angle position to be detected by the sensors 2, 3, and a sub-zone among the divided sub-zones having contributed for the detection of the area of original point continuously over a specified time is judged as the original point position.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used to determine the origin position (steering neutral position) of a rotating body that rotates in conjunction with steering wheel steering of a vehicle, etc. when the body is traveling straight ahead. The present invention relates to a suitable origin position determination device for a rotating body.

[Conventional technology]

Conventionally, in vehicles such as automobiles, a plurality of slits are opened at equal angular intervals (predetermined angular pitch) in a rotating disk that rotates in conjunction with the steering wheel, and two photointerrupters are placed adjacent to each other at the passing positions of these slits. It is arranged to perform various controls linked to steering wheel steering.

In other words, the first and second
A pulsed electrical signal (two-phase incremental signal) with the same waveform but with a phase shift of approximately 90″ is applied to the photo incrector.
This incremental signal is counted to detect the steering direction and steering angle.

Normally, it is impossible to detect the origin position using only the two-phase incremental signals mentioned above, so in order to detect the origin position, an origin slit is provided in the rotating disk, and the origin slit is passed through the third photointerrupter. A 3-bit configuration is used to obtain an origin signal, and a method is adopted in which the relative position of the rotating disk from the origin position is detected using an incremental signal.

However, considering misalignment of the serrations between the steering shaft and the steering wheel, mounting tolerances between the steering shaft and steering sensor, poor adjustment of the wheel alignment, etc., the assembly error reaches tens of inches in the worst case. Normally, in order to obtain the origin signal, the angular width of the origin slot 7) provided on the rotating disc is expanded, and even if there is an assembly error of several tens of degrees, as long as the vehicle is traveling straight, the origin signal can be obtained. It is assumed that you can obtain the following.

As a result, a problem arises in that the origin position cannot be specified only by the presence or absence of the origin signal. A steering position detection device has been proposed. That is, this steering position detection device includes a steering angle detection means that is provided on a steering member that rotates by a steering operation, detects a steering angle, and outputs a steering angle signal, and a steering angle detection means that detects a steering angle and outputs a steering angle signal. , a neutral zone detection 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. ,
The system is equipped with a neutral position calculation means that outputs this average value as a neutral position signal, and by using such a steering position detection device, the vehicle can be operated regardless of the maintenance status of the vehicle or the number of occupants in the vehicle. It is assumed that the steering neutral position can be detected in a straight-ahead state.

[Problem to be solved by the invention]

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

In addition, in order to calculate the average value of the steering angle signal when the steering neutral zone signal is detected, a moving average calculation is performed for weighting, and the average value is calculated. Due to the processing calculations, the circuit configuration becomes complicated.

[Means to solve the problem]

The present invention was made to solve such problems, and includes a slit zone provided on the outer peripheral edge surface at a predetermined angular pitch, and an origin zone provided with an angular width wider than the two angular pitches of the slit zone. a rotating body that rotates clockwise and counterclockwise in conjunction with an external operation; a rotational position detection means that detects the rotational angular position of the rotating body based on passage of the rotating body through a slit zone; origin range detection means for detecting the origin range of the rotating body based on passage of the origin zone of the body; and while the origin range is being detected by the origin range detection means, the rotation angle position detected by the rotational position detection means is The apparatus further comprises an origin position determination means for dividing the origin zone into a plurality of subzones based on the origin and determining a subzone that has contributed to the detection of the origin range for a predetermined period of time or more to be the origin position.

The present invention also includes origin position determination means for determining, as the origin position, a subzone that has contributed to the detection of the origin range for m consecutive periods of travel over a predetermined distance among the divided subzones.

[Effect]

Therefore, according to the present invention, in the origin zone, subzones that have contributed to the detection of the origin range for a predetermined period of time or longer are
Further, a subzone that continuously contributes to the detection of the origin range while traveling for a predetermined distance or more is determined as the origin position.

〔Example〕

Hereinafter, the 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 this origin position determining device. In the figure, reference numeral 5 denotes an UP which inputs a pulsed electric signal sent out by a rotational position detection sensor (steering angle sensor) 100 (Fig. 2) and sends out processed signals (up signal and down signal) according to steering wheel steering. /
DOWN switching circuit, 6 is this UP/DOWN switching circuit 5
This is an UP/DOWN counter that receives the processed signal sent out by the UP/DOWN counter.

The drift angle sensor 100 is composed of a rotating disk 1 that rotates in conjunction with steering wheel steering, and photointerrupters 2 to 4 each having a light emitting element and a light receiving element. Slits 1a of the same shape are opened at equal angular intervals (predetermined angular pitch P). Photo-interrupters 2 and 3 are arranged adjacent to each other at the position where the slit 1a passes, and the photo-interrupters 2 and 3 are affected by the passage of the slit la as the rotary disk 1 rotates, as shown in FIG. The cicada is designed to generate pulsed electric signals having the same waveform and alternating "1" level and "0" level as shown in (a) and (b). That is, from the steering state shown in Figure 2, if you turn the steering wheel clockwise (clockwise in Figure 2),
When an electrical signal in the positive direction centered on point N is rotated counterclockwise, an electrical signal in the negative direction centered on point N is generated. The electrical signal generated in the photo-interrupter 2 is 90 degrees ahead of the electrical signal generated in the photo-interrupter 3, and is at the origin position (steering neutral position) of the rotary disk 1, which is ideal in design, that is, at the third position. At point N shown in the figure, the electrical signal generated in the photointerrupter 2 is in the falling or rising period when it changes from the "1" level to the rOJ level or from the "0" level to the "1" level, and the photointerrupter 3
The electrical signal generated at is in the "0" level state. The electrical signals sent from the photointerrupters 2 and 3 are input to the UP/DOWN switching circuit 5.

On the other hand, at a predetermined rotation angle position on the outer peripheral edge surface of the rotating disk 1,
A slit 1b is independently provided as an origin zone, and passage through this slit lb is detected by a photo ink printer 4. That is, slit 1b
The rotational position facing the photo ink club 4 is the origin range of the rotating disk 1, and the angular width of this origin range, that is, the angular width α of the slit 1b, is determined by the deviation of the serrations between the steering shaft and the steering wheel, the steering shaft The setting has been expanded to exceed the worst-case assembly error, taking into account installation tolerances between the steering wheel and steering sensor, poor wheel alignment, etc. In this embodiment, the angular width α of the slit 1b is set to 60°, and according to the inventor's investigation, the worst case of the assembly error is 50＠
Since this value has been experimentally obtained, if the angular width α of the slit 1b is set to 60°, the electric signal sent by the photointerrupter 4 will always be at the "1" level when the vehicle is traveling straight. Origin range detection signal (Fig. 3)
C)) can be obtained. Then, this rlJ level origin range detection signal is transmitted to the terminal 10 in FIG.
1 through 3 person Kaand gate 14. and gate 3
9. rAJ input terminal of decoder 44 and inverter 41
via ANDGATE 40 and 3-person ORGATE 5
It is supplied to the first input terminal of 0.

Here, the photo ink club 4 is located at the center of the angular width α of the slit 1b at the ideal origin position in the design of the rotating disk 1, that is, at the point N shown in FIG. . In addition, in this embodiment, the slit 1
The angle width α of b is three times the angle width P of slit 1a (3
It is set slightly wider than the angular pitch).

On the other hand, the UP/DOWN switching circuit 5 processes the input pulsed electric signal and sends out a number of up and down signals from its output terminals 5a and 5b according to the amount of right and left steering of the steering wheel. However, the UP/DOWN counter 6 counts up or down its count value by the number of input up signals or down signals. That is, rotating disk 1
[IP/D
The count value in the OWN counter 6 is basically set to zero, and by turning the steering wheel to the right, the count value changes.
The signal is sequentially increased at each falling edge of the output of the photointerrupter 2. Further, by turning the steering wheel to the left, the count value is sequentially decreased at each rising edge of the output of the photointerrupter 2. That is, in Fig. 3, if the handle is rotated to the right from point N, UP/D will be achieved at point a.
The count value in the OWN counter 6 increases sequentially to +1 and +2 at point b, and if the rotation is made to the left from point N, the count value in the UP/DOWN counter 6 increases to -1 at point C and d. -2 at point
It will gradually go down. And UP/DOW
The count value in the N counter 6 is given to the decoder 7, and the decoder 7 selects an output terminal (not shown) at a position corresponding to the supplied count value, and sets the level to rOJ or "1". The controller is configured to control external equipment, such as a cornering lamp system, which is operated in conjunction with steering wheel steering.

As described above, the origin range detection signal is input to the first input end of the three-person gate 14 via the photo ink converter 4 shown in FIG.
The clock signal sent out from the reference clock generator 15 is input to the input terminal of the controller, and the processed signal thereof is input to the third input terminal via the vehicle speed detection circuit 16. There is. The vehicle speed detection circuit 16 includes resistors R1 to R
8, capacitor CI, C2, diode D1, transistor Q1. Q2 and comparator CP. Based on the vehicle speed signal input through terminal 102, when the vehicle speed increases, the processed signal to AND gate 14 via comparator CP is set to rlJ level. That is, while the vehicle is stopped, the output of the comparator CP is at the "0" level. And this and gate 1
4 is supplied to the counter 37, and by its count-up operation based on this supplied clock signal, the counter 37 sends out an overflow signal (CARRY signal) of the "1" level, and this The CARRY signal at the "1" level is applied to the UP/DOWN counter 6 via the OR gate 35 as a reset signal.

On the other hand, the comparison output sent out by the comparator 42 is input to the other ends of the AND gates 39 and 40, and when a predetermined voltage is applied to the terminal 103 at the same time as the power is turned on, the comparator 42 The comparative output is set to the "1" level immediately, and based on the increase in the charge level to the capacitor C3, the comparative output is set to the "1" level after a predetermined delay.
0'' level. and,
The output of the AND gate 39 is input to the other end of the OR gate 35, the output of the AND gate 40 is input to the set terminal of the flip-flop 430, and the Q output of the flip-flop 43 is input to the rBJ input terminal of the decoder 44. It has become a given. A down signal and an up signal are input to the "C" and rDJ input terminals of the decoder 44 via the UP/DOWN switching circuit 5, and the decoder 44 has its input terminals rDJ, rCJ.
, rBJ.

When the rOJ, rlJ, rlJ, and rlJ signals are input to rAJ, the level of the output terminal 44a is set to "
1", and when the rlJ, rOJ, rlJ, rlJ signals are input, the level of the output terminal 44b is set to "1".
It is said that When a "1" level signal is sent from the output terminal 44a of the decoder 44, this signal is input as a load signal to the UP/DOWN counter 6 via the OR gate 45, and the output state of the decoder 44 at this time is changed. Based on the encoder 46, tl
The count value in the P/DOWN counter 6 is set to +1. Further, when a signal of "1" level is sent from the output terminal 44b of the decoder 44,
This signal is input as a load signal to the UP/DOWN counter 6 via the OR gate 45, and based on the output state of the decoder 44 at this time, it is sent to the UP/DOWN counter 6 via the encoder 46.
The count value in the lP/DOWN counter 6 is set to -1.

Further, the up signal and down signal sent out by the U P / D OW N switching circuit 5 are also input to a one-shot multivibrator (hereinafter simply referred to as one-shot) 49 via an OR gate 48. ,
The one-shot signal sent out from the one-shot 49 in response to the input up signal and down signal is
It is applied to the second input terminal of the three-input OR gate 50. The comparison output of the comparator 42 is given to the third input terminal of the 3-input OR gate 50, and the "1" level signal passing through the 3-input OR gate 50 is provided to the counter 37 as its reset signal. It has become a thing.

Note that the load signal output from the OR gate 45 is also input manually to the one shot 47, and the one shot 47 is activated at the falling edge of this input load signal, and the one shot 47 is sent out. The flip-flop 43 is reset by the one-shot signal.

Next, the operation of the device configured in this way will be explained.

Now, if the car is traveling straight and the rotary disk 1 is in the true straight-ahead steering position, it is assumed that it is located at the ideal design origin position as shown in FIG. While the origin range detection signal at the "1" level is being input, the count value in the tlP/DOWN counter 6 is warmly longer for the time period in which it continues to be +0 than the time period in which it continues to be +1 and -1. That is, terminal 10
While the origin range detection signal at the "1" level is being inputted via the reference clock generator 15, the clock signal sent from the reference clock generator 15 passes through the AND gate 14 and is supplied to the counter 37. When a predetermined period of time has elapsed with the count value in the UP/DOWN counter 6 maintaining ±O, that is, the UP/DOWN
When a predetermined period of time has elapsed without either an up signal or a down signal being sent from the /DOWN switching circuit 5, a CARRY signal of rlJ level is sent out from the counter 37 by a count-up operation based on the supplied clock signal, and this "1"
” level CARRY signal passes through the OR gate 35 to the U
It is given to the P/DOWN counter 6. As a result, t
The count value in the lP/DOWN counter 6 is returned to +0. In this case, the count value in the IIP/DOWN counter 6 is already +0, and in this way, the count value in the UP/DOWN counter 6 will always maintain +0 at the straight-ahead steering position.

In other words, by appropriately determining the number of increments until the manual clock signal overflows to the counter 37, the counter can be The counting operation of the clock signal in 37 is reset based on the amplifier signal and down signal via the UP/DOWN switching circuit 5.

On the other hand, in cases where the rotating disk 1 is deviated from the ideal design origin position due to assembly errors, the correction operation that is a feature of this embodiment can be quickly performed as follows. This makes it possible to control external devices in conjunction with the steering wheel without any problems.

In other words, when the rotating disk 1 is at the original position ideally designed, 22 (
When the range up to point b) is defined as the origin zone at lb), the vehicle is traveling straight within the region from point 0 to point a that divides this origin zone (hereinafter, this region is referred to as the first subzone). , the count value in the tlP/DOWN counter 6 continues to be ±0 for a longer time. but,
If the rotating disk 1 deviates from the ideal design origin position due to the assembly error, the count value on the UP/DOWN counter 6 will increase by +1 while driving straight.
Alternatively, the time it takes to continue -l becomes longer. That is, within the area from point a to point b (hereinafter referred to as the second subzone) that divides the origin zone, or within the area from point 0 to point d (hereinafter referred to as the third subzone). ), the time during which the count value in the LIP/DOWN counter 6 continues to be +1 or -1 is the first
This is much longer than the time it takes to continue ±O within the subzone.

The longer the count value in the UP/DOWN counter 6 continues to be +1 in the second subzone, the more
When the count value of the /DOWN counter 6 is +1, that is, when the second subzone among the three subzones is detected, the counter 37 indicates that the C level is "1".
The ARRY signal will be sent, and this will cause the UP
/DOWN The count value in counter 6 is returned to +0. That is, the second subzone is quickly determined to be the origin position, and the count value in the UP/DOWN counter 6 is corrected.

Also, in the third subzone, UP/DOWN counter 6
When the count value of the UP/DOWN counter 6 is -1 for a longer period of time, that is, when the third subzone of the three subzones is being detected, the counter 37, a CARRY signal of "1" level is sent out, and as a result, the count value in the IP/DOWN counter 6 becomes +
Returned 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.

Note that while the vehicle is stopped, the output of the comparator CP in the vehicle speed detection circuit 16 is at the "0" level, so the clock signal sent from the reference clock generator 15 can pass through the AND gate 14. The duration that contributes to the detection of the origin range of the first to third subzones is not accumulated by the counter 37.

Immediately after the power is turned on to this device, the comparison output sent out by the comparator 42 continues for a predetermined period of time.
” level. Therefore, when the power is turned on while the origin range detection signal of the “1” level is input through the terminal 101, the comparison output of the “1” level sent by the comparator 42 is output to the AND gate 39. Pass through and Or Gate 35
The count value in the UP/DOWN counter 6 is forcibly set to +0 via the UP/DOWN counter 6, and as a result, the subzone that was detected immediately after the power was turned on is set as the initial origin position.

Further, when the power is turned on when the origin range detection signal of the "1" level is not inputted via the terminal 101, a signal of the "1" level is inputted to the AND gate 40 via the inverter 41, and this Passing through AND Gate 40
1'' level comparison output causes the flip-flop 43 to
becomes the cent state. As a result, rB of the decoder 44
The "1" level Q output of the flip-flop 43 is now set to the J input terminal. Then, when the origin range detection signal at the "1" level is inputted through the terminal 101 due to subsequent steering wheel steering, this origin range detection signal at the "1" level is set to the rAJ input terminal of the decoder 44. Become so.

Now, suppose that a "1" level origin range detection signal is generated due to clockwise rotation of the rotary disk 1 due to right steering, then a "1" level amplifier signal is generated from the tlP/DOWN switching circuit 5 due to this right steering. Due to the setting to the "D" input terminal of the decoder 44, the level of the output terminal 44b of the decoder 44 becomes "1" level at this point, and the count value in the UP/DOWN counter 6 becomes -1 in the third subzone.
, and the first subzone among the three subzones is set as the initial origin position. Also,
Assuming that a "1" level origin range detection signal is generated due to counterclockwise rotation of the rotary disk 1 due to left steering, a decoder for a "1" level down signal from the UP/DOWN switching circuit 5 due to left steering is generated. 44 to the rCJ input terminal, at this point the level of the output terminal 44a of the decoder 44 is set to "1" level, the count value in the UP/DOWN counter 6 is set to +1 in the second subzone, and the three subzones are The first subzone is set as the initial origin position.

FIG. 4 is a block diagram showing another embodiment of the origin position determining device according to the present invention. In this figure, the same reference numerals as in FIG. 1 indicate the same constituent elements, and the explanation thereof will be omitted. In this embodiment, an origin range detection signal via a terminal 101 is input to an AND gate 14'', while a pulse signal (distance signal) corresponding to the travel distance is input via a terminal 104 to the other end of this AND gate 14''. It is assumed to be input.

Then, the distance signal passing through the AND gate 14 is provided to the counter 37, and when the distance traveled exceeds a predetermined value based on this distance signal, the counter 37 sends rl
It is assumed that a J level CARRY signal is sent.

That is, among the three subzones, the subzone that continuously contributed to the detection of the origin range while traveling for a predetermined distance or more is determined to be the origin position, and the count value in the UP/DOWN counter 6 is set to +0 in this determined subzone.
It is assumed that it will be returned to . With this configuration, the vehicle speed detection circuit 16 shown in FIG. 1 becomes unnecessary, that is, there is no need to deal with the detection of the origin range while the vehicle is stopped.
In addition, the faster the traveling speed, the faster the origin position can be determined.

In addition, in the above-described embodiment, when dividing the origin zone into a plurality of subzones, the division is performed using the minimum resolution of the steering angle sensor, but the setting of these subzones does not necessarily have to be the minimum resolution of the steering angle sensor. Instead, it may be an integer multiple of this minimum resolution. Further, when the subzones are set to an integral multiple of the minimum resolution, each subzone may have a mutually overlapping portion.

Furthermore, in the above-described embodiment, the angular width α of the slit ib is set to be slightly wider than the 3-angle pitch of the slit 1a, but it may be set to an angular width wider than at least the 2-angle pitch of the slit 1a. By doing this, the origin zone can be divided into multiple subzones based on the steering angle position detected by the steering angle sensor, and the origin position can be accurately determined within the expanded origin zone. Become.

In addition, in the above-mentioned embodiment, the determination of the neutral steering position in a vehicle was explained as an example, but the determination is not limited to vehicles only, and the determination of the origin position of various rotating bodies that rotate in conjunction with external operations is described. This method is suitable for application to various controls based on the determined origin position, and has extremely high utility value. In addition, in the embodiment, the device for determining the origin position of the rotating body is configured as hardware using a specific circuit, but it goes without saying that it is also possible to implement it using software technology using a microcomputer, etc. .

As an example showing the basis of this embodiment, there is Japanese Patent Application No. 1983-78529 (device for determining the origin position of a rotating body) filed by the present applicant. A large number of memory areas are required to store the cumulative time that contributed to the detection. On the other hand, if the origin position determination device of this embodiment is used, the memory area can be saved, the circuit configuration can be simplified, and costs can be reduced compared to the method of storing the cumulative time described above. It becomes possible.

〔Effect of the invention〕

As explained above, according to the device for determining the origin position of a rotating body according to the present invention, there are slit zones provided at a predetermined angular pitch on the outer peripheral surface thereof and an origin provided with an angular width wider than the two angular pitches of the slit zones. a rotating body having a zone and rotating clockwise and counterclockwise in conjunction with an external operation; a rotational position detection means for detecting the rotational angular position of the rotating body based on passage of the rotating body through a slit zone; origin range detection means for detecting the origin range of the rotating body based on passage of the origin zone of the rotating body; and while the origin range is detected by the origin range detection means, the rotational angular position detected by the rotational position detection means; The present invention also includes an origin position determining means for dividing the origin zone into a plurality of subzones based on the above, and determining a subzone that has contributed to the detection of the origin range for a predetermined period of time or more to be the origin position. Since we are equipped with an origin position determination means that determines as the origin position a subzone that continuously contributes to the detection of the origin range while traveling for a predetermined distance or more, out of the divided subzones, it is possible to detect a subzone that continuously contributes to the detection of the origin range while traveling for a predetermined time or more during the origin zone! ! Subsequently, the subzone that contributed to the detection of the origin range, or the subzone that continuously contributed to the detection of the origin range while driving for a predetermined distance or more, can be determined as the origin position.For example, this rotating body can be used to operate the steering wheel of the vehicle. When the wheels are rotated in conjunction with each other, the neutral steering position can be determined accurately and quickly with a simple circuit configuration.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing an embodiment of the origin position determining device for a rotating body according to the present invention, FIG. 2 is a schematic configuration diagram showing a steering angle sensor used in this device, and FIG. 3 is a block configuration diagram showing this steering angle sensor. FIG. 4 is a block diagram showing another embodiment of this origin position determining device. 1... Rotating disk, 1a... Slit, 1b... Slit, 2, 3.4... Photo interrupter, 5...
・UP/DOWN switching circuit, 6...UP/DOWN counter, 14...3 person gate, 14'
...And gate, 15...Reference clock generator, 3
7... Counter, 48... Or gate, 49...
One shot, 50...3 man power or gate. Patent applicant: Koito Manufacturing Co., Ltd.

Claims (2)

[Claims] (1) It has a slit zone provided at a predetermined angular pitch on its outer peripheral edge surface and an origin zone provided with an angular width wider than the two angular pitches of this slit zone, and can be used as a clock or counterclockwise in conjunction with external operation. a rotating body that rotates in a direction, a rotational position detection means for detecting a rotational angular position of the rotating body based on the passage of the slit zone of the rotating body, and an origin range of the rotating body based on the passing of the origin zone of the rotating body. and, while the origin range is being detected by the origin range detection means, dividing the origin zone into a plurality of subzones based on the rotation angle position detected by the rotational position detection means; An origin position determining device for a rotating body, comprising: an origin position determination means for determining a subzone that has contributed to the detection of an origin range for a predetermined period of time or longer to be an origin position. (2) It has a slit zone provided at a predetermined angular pitch on its outer peripheral edge surface and an origin zone provided with an angular width wider than the two angular pitches of this slit zone, and can be used to clock or counterclockwise in conjunction with external operation. a rotating body that rotates in a direction, a rotational position detection means for detecting a rotational angular position of the rotating body based on the passage of the slit zone of the rotating body, and an origin range of the rotating body based on the passing of the origin zone of the rotating body. and, while the origin range is being detected by the origin range detection means, dividing the origin zone into a plurality of subzones based on the rotation angle position detected by the rotational position detection means; An apparatus for determining an origin position of a rotating body, comprising an origin position determination means for determining, as an origin position, a subzone that continuously contributes to the detection of an origin range while traveling a predetermined distance or more.