JPH0794980B2 - 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, this steering position detecting device is provided on a steering member that is rotated by a steering operation, and has a steering angle detecting means for detecting a steering angle and outputting a steering angle signal, and a steering position corresponding to an actual steering angle zero point. , A predetermined steering range (origin range in the present invention) is detected and a neutral zone detecting means for outputting a steering neutral zone signal, and an average value of the steering angle signal when the steering neutral zone signal is detected are calculated. , And a neutral position calculating means for outputting the average value as a neutral position signal, and by using such a steering position detecting device, the vehicle is irrespective of the maintenance condition of the vehicle or the occupant condition of the vehicle. It is assumed that 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 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. An origin position determination unit that determines the maximum subzone as the origin position is provided, and when updating the determination result of the origin position, the adjacent subzones in the subzone direction in which the integrated time becomes maximum within a predetermined time are set as the origin positions. The judgment is made.

[Action]

Therefore, according to the present invention, when the origin position before the determination and the origin position after the determination are not adjacent to each other, the origin position is shifted to the adjacent subzones one by one, and the true origin position is set for each subzone. It is possible to make it asymptotic.

〔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). The 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 pass through the slit 1a as the rotary disc 1 rotates, so that FIG. Further, as shown in (b) and (b), pulsed electric signals of the same waveform with alternating "1" level and "0" level are generated. That is, 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 N point is rotated counterclockwise. When rotated, an electric signal in the negative direction centering on the N point is generated. 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 °, the origin range detection signal of level "1" (Fig. 3 (c)) can be obtained 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 rising 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 of the OWN counter 6 is input to the decoder 7 and the digital comparators 8 to 10. The decoder 7 selects the output terminal at the position corresponding to the input count value and sets its level to "0". Or "1" is configured to control an external device that operates in conjunction with steering of the steering wheel, such as a cornering lamp system. Although only the output terminal 7a of the decoder 7 is shown in this figure, when the count value of the UP / DOWN counter 6 is ± 0, this output terminal 7a
The output level of 7a is "1".

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 to the comparator 8 as the count value of the UP / DOWN counter 6 as the reference value of right 1 bit or more, and the comparator 10 is set to
As the count value of the UP / DOWN counter 6, -1 is set as the reference value of the left one bit or less. In the comparator 9, ± 0, which is the count value of the UP / DOWN counter 6, is set as the center reference value.
When the count value input via the counter 6 is ± 0, the output level of the comparator 9 is “1”. Further, when the count value input through the UP / DOWN counter 6 is +1 or more (≧ 1), the output level of the comparator 8 becomes “1” and UP / DOW
When the count value input through the N counter 6 is -1 or less (≤1), the output level of the comparator 10 is "1". Then, the "1" level signal sent from the comparators 8 to 10 is the AND gate.
The output of the AND gate 14 is input to the other ends of the AND gates 11 to 13. 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 reference 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 is a resistor
It is composed of R1 to R8, capacitors C1 and C2, diode D1, transistors Q1 and Q2, and comparator CP.
When the vehicle speed is generated based on the vehicle speed signal input via the terminal 102, the output of the comparator CP to the AND gate 14 is set to the "1" level. That is, while the vehicle is stopped, the output of the comparator CP is "0".
It has become a 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. The latch circuits 21 to 23 are loaded 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. And Nand Gate 28 and The output of the AND gate 13 is branched and input to the other end of 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 other ends of the NAND gates 31 and 32 are input. The output of the AND gate 11 is branched and input. The outputs of NAND gates 28 and 29 are fed to NAND gate 47 and NAND gate 47.
The outputs of 30 and 33 go to NAND gate 48 and NAND gate 31.
The outputs of NAND gates 49 and 32 are input to NAND gate 49, the outputs of NAND gates 47 and 49 are input to the set terminals of flip-flops 62 and 63, and the Q outputs of flip-flops 62 and 63 are AND gates 34 and 35. To one end of the OR gates 51 and 50. At the other ends of the AND gates 34 and 35, "1" generated at the output terminal 7a via the decoder 7
A level signal is input, and the outputs of the AND gates 34 and 35 are input to the first and second input ends of the 4-input OR gate 60. Then, the output of the NAND gate 48 goes up / down via the OR gate 61.
It is input to the OWN counter 6 and UP / D is generated by the signal of "1" level passing through this OR gate 61.
The count value in OWN counter 6 is reset ± 0
It is supposed to be returned to.

Further, the one-shot 36 is operated based on the one-shot signal sent by the one-shot 20, and the one-shot signal sent by the one-shot 36 is a counter.
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 ring counter 37, and repeatedly sends the one-shot signals to the latch circuits 21 to 23 every predetermined time. In addition,
While the comparison output of the comparator CP in the vehicle speed detection circuit 16 is at "1" level, the counter 37 receives the clock signal sent from the reference clock generator 15 as the AND gate 38.
It is supposed to be input via.

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 61, and the output of the AND gate 40 is the flip-flop 43.
Of the flip-flop 43, and the Q output of the flip-flop 43 is input to the “B” input terminal of the decoder 44. UP / D at the “C” and “D” inputs of decoder 44
The down signal and the up signal are inputted through the OWN switching circuit 5, and the decoder 44 has "0", "0", at its input terminals "D", "C", "B", "A".
When a signal of "1", "1", "1" is input, the level of the output terminal 44a is set to "1", "1",
When the signals of "0", "1" and "1" are input, the level of the output terminal 44b is set to "1". When "D", "C", "B", and "A" are combinations other than those in Table 3, the levels of the output terminals 44a and 44b are both "0".

The "1" level signals sent from the output terminals 44a and 44b of the decoder 44 are input to the third and fourth input ends of the OR gate 60 and the other ends of the OR gates 51 and 50. , The one-shot 52 is activated by the passage of the “1” level signal through the OR gate 60, and the one-shot signal transmitted by the one-shot 52 is
The load signal is input to the UP / DOWN counter 6. Then, when this load signal is input and the “1” level signal is input to the encoder 46 after passing through the OR gate 51, the outputs Q _{A to} Q _D of the encoder 46 at this time are captured. , UP / D
The counter value in the OWN counter 6 is set to +1. When the load signal is input and the “1” level signal is input to the encoder 46 through the OR gate 50, the encoder 46 at this time is
By taking in the outputs Q _{A to} Q _D of, the count value of the UP / DOWN counter 6 is set to -1.

The one-shot 53 is activated at the falling edge of the one-shot signal transmitted by the one-shot 52, and the one-shot signal transmitted by the one-shot 53 causes the flip-flops 43, 62, 63 and the latch circuit 21.
The latch data in ~ 23 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 or more, the comparator 8 sends out a signal of "1" level and UP.
When the count value of the / DOWN counter 6 is -1 or less, the comparator 10 outputs a "1" level signal.
Further, when the count value of the UP / DOWN counter 6 is ± 0, the comparator 9 sends a signal of "1" level. Then, based on the "1" level signal sent from the comparators 8-10, the reference clock generator 15 passing through the AND gate 14 while the "1" level origin range detection signal is being input through the terminal 101. The clock signal from
It passes through AND gates 11 to 13 and is input to counters 17 to 19. That is, when the count value of the UP / DOWN counter 6 is +1 or more, the count value of the counter 17 is integrated and increases, and when the count value of the UP / DOWN counter 6 is -1 or less, the count value of the counter 19 is integrated. Been up and up. Also, UP / DOWN counter 6
When the count value at is 0, the counter value at the counter 18 is integrated and increased. The count value in each counter is determined by the latch circuit by the falling edge of the one-shot signal sent by the one-shot 20.
It will be taken in by 21-23. On the other hand, the counters 17 to 19 after the count value is captured are one-shot
It is reset by the one-shot signal sent by 36, its count value is returned to zero, and the clock signal to be input next is prepared for counting. That is, the counters 17 to 19 count clock signals input within a predetermined time (in this embodiment, 1 minute) determined by the output cycle of the CARRY signal transmitted by the counter 37,
The latch circuits 21 to 23 hold the count values counted by the counts 17 to 19 within this predetermined time.

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 reference clock generator 15, the other ends of the NAND gates 30 and 33 become "1" level, and the output level of the NAND gate 48 becomes "1". A reset signal is input to the UP / DOWN counter 6 via the OR gate 61, and the count value becomes ± 0. 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 rotary disc 1 is at the origin position which is ideal in design, when the range from the point Z1 (d) to Z2 (b) shown in FIG. 3 is set as the origin zone in the slit 1b,
Within the area from point c to point a that divides this origin zone (hereinafter this area is called the first subzone), the time during which the UP / DOWN counter 6 keeps the count value of ± 0 during straight traveling. become longer. However, when the rotary 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 becomes +1 or -1 during straight traveling. The maintenance period becomes longer. 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). ), UP
The counter value in the / DOWN counter 6 is +1 or-
The integration time of 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
Of 21 to 23, the count value α held by the latch circuit 21 becomes the maximum, and a signal of “1” level is transmitted from the output terminal 27g or 27h of the decoder 27. And
At the time 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 the output level of the NAND gate 49. Becomes "1" and the flip-flop 63 is set. The "1" level Q output sent from the flip-flop 63 is set in the encoder 46 via the OR gate 50. As a result, the outputs Q _{A to} Q _D of the encoder 46 are −1.
An output state indicating (count value) is set (see Table 4). Under these circumstances, when the level of the output terminal 7a of the decoder 7 becomes "1", that is, when the counter value of the UP / DOWN counter 6 becomes ± 0 as the steering wheel is steered, the AND gate 35 and the flip-flop 63 " The one-shot level Q output passes, and the one-shot 52 operates by the Q-output of the "1" level passing through the OR gate 60, and the one-shot signal sent by the one-shot 52 is sent to the UP / DOWN counter 6. It is input as a load signal. Then, by the input of the load signal, the UP / DOWN counter 6 takes in the outputs Q _{A to} Q _D of the encoder 46 at this time and sets the count value from ± 0 to −1 indicated by Q _{A to} Q _D. change. As a result, the count value in the UP / DOWN counter 6 becomes the first
-1 in the sub-zone and ± 0 in the second sub-zone,
The second subzone is quickly determined as the origin position and UP / DOW
The correction of the count value in the N counter 6 is promptly performed.

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 counter value γ held by the latch circuit 23 among the latch circuits 21 to 23 becomes the maximum, and the decoder 27 Output terminal 27d or 27e
As a result, a "1" level signal is transmitted. Then, when the clock signal passes through the AND gate 13,
That is, at the time when the third subzone is detected among the three subzones, the other ends of the NAND gates 28 and 29 become the "1" level, the output level of the NAND gate 47 becomes the "1", and the flip-flop 62 is turned on. Set to the set state. Then, "1" sent from the flip-flop 62
The Q output of the level is set to the encoder 46 via the OR gate 51. This allows encoder 46 outputs Q _{A to} Q
_D becomes an output state indicating +1 (count value) (Table 4
reference). Under these circumstances, when the level of the output terminal 7a of the decoder 7 becomes "1" as the steering wheel is steered, that is, UP
When the count value of the / DOWN counter 6 becomes ± 0,
The "1" level Q output of the flip-flop 62 passes through the AND gate 34, and the "1" level Q output passes through the OR gate 60 to activate the one-shot 52.
The one-shot signal sent by this one-shot 52 is UP / D
It is input to the OWN counter 6 as a load signal. Then, by the input of this load signal, the UP / DOWN counter 6 takes in the outputs Q _{A to} Q _D of the encoder 46 at this time,
The count value is changed from ± 0 to +1 indicated by Q _{A to} Q _D. As a result, the count value in the UP / DOWN counter 6 becomes +1 in the first subzone and ± 0 in the third subzone, the third subzone is quickly determined as the origin position, and the count value in the UP / DOWN counter 6 The correction will be performed promptly.

Furthermore, in the present embodiment, considering a special traveling state such as when traveling on a road surface that is greatly inclined to the left and right, in this case, the determination result of the origin position is rapidly updated between distant subzones. In order to prevent this, the following one-cushion UP / DOWN counter 6 corrects the count value. That is, for example, assuming that the determination result that the origin position is in the third subzone is now obtained, the count value in the UP / DOWN counter 6 is ± 0 in the third subzone due to steering of the steering wheel.
+1 in the first subzone and +2 in the second subzone (see Table 5) In such a state, based on the special traveling state described above, UP occurs during the generation period of the origin range detection signal of "1" level.
Assuming that the integration time when the count value of the / DOWN counter 6 becomes +2 becomes long, the UP / DOWN counter 6
The count value α held in the latch circuit 21 among the latch circuits 21 to 23 becomes the maximum, based on the comparison result in the comparator 8 that the count value in is greater than or equal to +1.
The output terminal 27g or 27h of the decoder 27 becomes "1" level, and when the clock passes through the AND gate 11, the output of the NAND gate 49 becomes "1" level and the flip-flop 63 is set. The "1" level Q output sent from the flip-flop 63 is the OR gate.
It is set to the encoder 46 via 50. As a result, the outputs Q _{A to} Q _D of the encoder 46 enter an output state indicating -1 (count value) (see Table 4). Under such a circumstance, when the level of the output terminal 7a of the decoder 7 becomes "1", that is, when the count value of the UP / DOWN counter 6 becomes ± 0 as the steering wheel is steered, the AND gate 35 is set to "1" of the flip-flop 63. The "Q" output of "" level passes, and the Q output of "1" level passes through the OR gate 60 to activate the one-shot 52, and the one-shot signal sent by the one-shot 52 is loaded to the UP / DOWN counter 6. It is input as a signal. Then, by the input of this load signal, the UP / DOWN counter 6 takes in the outputs Q _{A to} Q _D of the encoder 46 at this time and changes the count value from ± 0 to Q _{A to} Q _D.
Change the setting to -1. As a result, the value of the UP / DOWN counter 6 becomes −1 in the third subzone, ± 0 in the first subzone, and +1 in the second subzone (Table 5
reference). After that, the flip-flop 63 is reset by the one-shot signal sent from the one-shot 53.

As a result, this time, during the generation period of the origin range detection signal of "1" level, the integration time for which the count value becomes +1 in the UP / DOWN counter 6 becomes long, and the comparator 8
Based on the result of the comparison, the count value α held in the latch circuit 21 becomes maximum again, and the flip-flop 63 is reset when the clock passes through the AND gate 11. Then, based on the "1" level Q output sent from the flip-flop 63, UP is performed in the same manner as described above.
When the count value of the / DOWN counter 6 becomes ± 0, the count value is changed to -1. As a result, the value of the UP / DOWN counter 6 becomes −2 in the third subzone, −1 in the first subzone, and ± 0 in the second subzone (see Table 5).

After that, during the generation period of the origin range detection signal of "1" level,
In the UP / DOWN counter 6, the integration time for which the count value becomes ± 0 becomes long, and the count value β held in the latch circuit 22 becomes maximum. In this way, the determination result of the origin position becomes the third value. The subzone is updated to the second subzone through the first subzone. That is, when the origin position is updated all at once from the third subzone to the second subzone, the variable position in the irradiation direction of the headlight based on the count value of the UP / DOWN counter 6 changes abruptly. As a result, the driver may be 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 adjacent to each other, the origin position is updated in one cushion, so the cornering lamp system is used. There is no sudden change in the irradiation direction of the headlight.

When the vehicle is stopped, the output of the comparator CP in the vehicle speed detection circuit 16 becomes "0" level, so the clock signal from the reference clock generator 15 is AND gate.
The time that cannot pass through 14 and contributes to the detection of the origin range of the first to third subzones at the origin position is the counter.
It is not accumulated in 17 to 19.

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 OR gate 61
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.

Further, when the origin range detection signal of "1" level is not input through the terminal 101 (the origin range detection signal is "0").
When the power is turned on (in the case of the level), a "1" level signal is input to the AND gate 40 via the inverter 41, and the flip-flop 43 is set by the comparison output of the comparator 42 passing through the AND gate 40. It becomes a state. 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, by steering the steering wheel thereafter, the terminal 101
When the "1" level origin range detection signal is input via the, the "1" level origin range detection signal is set to the "A" input terminal of the decoder 44.
Now, if it is assumed that the origin range detection signal of "1" level is generated by the right rotation of the rotating disk 1 associated with the right steering (see FIG. 4 (a)), the UP / DOWN switching circuit 5 associated with the right steering. The "D" input signal from the decoder 44 is set to the "D" input terminal of the up signal of "1" level from "D", "C", "B", "A".
Becomes "1", "0", "1", "1", and the decoder 44
The level of the output terminal 44b of this becomes "1" level (see Table 3). The "1" level signal from the output terminal 44b of the decoder 44 is given to the UP / DOWN counter 6 via the OR gate 60 as a load signal. Upon receiving this load signal, the UP / DOWN counter 6 outputs the encoder 46 outputs Q _{A to} Q _D.
Take in. At this time, since the outputs Q _{A to} Q _D of the encoder 46 are “0” at the output terminal 44 a of the decoder 44 and “1” level at 44 b, that is, the output of the OR gate 51 is “0” and the output of the OR gate 50 is Since the level is "1", it indicates -1 (count value) (see Table 4). This allows UP / D
The count value in the OWN counter 6 is set to -1,
That is, -1 in the third subzone and ± in the first subzone.
0, set to +1 in the second subzone, and the first subzone among the three subzones is set as the initial origin position.

Further, it is assumed that the origin range detection signal of "1" level is generated by the left rotation of the rotary disc 1 accompanying the left steering (fourth
Fig. (B)), UP / DOWN switching circuit 5 associated with this left steering
"C" of decoder 44 for "1" level down signal from
Depending on the setting at the input end, "D", "C", "B",
"A" becomes "0", "1", "1", "1", and the level of the output terminal 44a of the decoder 44 becomes "1" level (see Table 3). The "1" level signal from the output terminal 44a of the decoder 44 is given to the UP / DOWN counter 6 via the OR gate 60 as a load signal. Upon receiving this load signal, the UP / DOWN counter 6 takes in the outputs Q _{A to} Q _D of the encoder 46. At this time, the encoder output Q _A ~
In Q _D , output terminal 44a of decoder 44 is "1", 44b is "0"
Since it is at the level, that is, the output of the OR gate 51 is at "1" and the output of the OR gate 50 is at "0", +1 (count value) is shown (see Table 4). As a result, the count value of the UP / DOWN counter 6 is +
1, that is, +2 in the second subzone, ± 0 in the first subzone, -1 in the third subzone, and the first 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. .

Further, in the present embodiment, the origin zone is divided into three, but it may be divided into smaller ones. Even in such a fine division, the integration time contributing to the detection of the origin range is predetermined. By determining the sub-zones adjacent to each other in the direction of the maximum sub-zone in time as tentative origin positions, the origin positions are shifted one by one to the adjacent sub-zones so that each sub-zone gradually approaches the true origin position. It goes without saying that you can do it.

As an example showing the basics of this embodiment, there is Japanese Patent Application No. 60-298018 (method for determining the center position of a rotating body) by the present applicant. In this method, the angular width of the slit for detecting the origin position is used. Is narrow, the purpose of this embodiment cannot be achieved.

Further, 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 only the vehicle, and it is possible to determine the origin 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 determination device for the rotating body is configured 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. .

〔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 edge surface thereof at a predetermined angular pitch and the origin provided at an angular width wider than the 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 sub-zones, and the time contributing to the detection of the origin range of each of the divided sub-zones is integrated. An origin position determining means for determining the largest subzone within the origin position, and when updating the determination result of the origin position, the adjacent subzone in the subzone direction where the accumulated time becomes maximum within a predetermined time is the origin. Since the position is determined as the position, if the origin position before the determination and the origin position after the determination are not adjacent subzones, the true origin is calculated for each subzone while shifting the origin position one by one to the adjacent subzones. It becomes possible to asymptotically approach the position. For example, when this rotating body is rotated in conjunction with the steering wheel 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. FIG. 4 is a diagram showing an output waveform of the steering angle sensor, and FIG. 4 is a diagram showing a situation where the slit 1b in the rotating disc 1 of the steering angle sensor and the photo interrupter 4 face each other. 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
...... Reference clock generator, 17 to 19 …… Counter, 21 to 23
...... Latch circuit, 24-26 …… Comparator, 27 …… Decoder, 37 …… Ring 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. Point position determining means, and when updating the determination result of the origin position, a subzone adjacent in the subzone direction in which the integrated time becomes maximum within a predetermined time is determined as the origin position. Device for determining the origin position of a rotating body.