JPH0799330B2 - 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 arises a problem that the origin position cannot be specified only by the presence or absence of the origin signal, and in order to solve such a problem, as disclosed in JP-A-61-28811. A steering position detecting device has been proposed.
That is, 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 the above, the origin zone is divided into a plurality of subzones, and the time that contributed to the detection of the origin range of each of the divided subzones is added up. And an origin position determining means for determining a subzone that has reached the origin position as the origin position, and when the determination result of the origin position is updated, the subzone adjacent to the subzone in which the integrated time reaches the predetermined time earliest is the origin. The position is determined.

[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 for inputting a 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 bundle steering, and photointerrupters 2 to 4 having a light emitting element and a light receiving element. 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 °, 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. . This "1" level origin range detection signal is sent through its terminal 101 in FIG. 1 via the 3-input AND gate 14, AND gate 23, "A" input terminal of the decoder 26 and the inverter 27. AND gate 24 and 4
It is to be input to the input OR gate 20. Here, the photo interrupter 4 is located at the center of the angular width α of the slit 1b at the origin position that is ideal in designing the rotary disc 1, that is, at the point N shown in FIG. 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 in the UP / DOWN counter 5 is basically set to zero with reference to the ideal origin position in the design of the rotary disk 1, and the count value is right-turned by the steering wheel 2 and the photo interrupter 2 is set to the count value. The output is sequentially increased at each falling edge. In addition, the count value by steering the steering wheel to the left,
The photo interrupter 2 sequentially goes down at each rising edge of the output. That is, in FIG. 3, if the handle is rotated to the right from the N point as the starting point, the count value of the UP / DOWN counter 6 is sequentially increased to +1 at the point a and to +2 at the point b. If you rotate to the left from the point, at point c
The count value of the UP / DOWN counter 6 sequentially decreases to -1 and to -2 at the point d. And
The count value in the UP / DOWN counter 6 is the decoder 7
And the digital comparators 8 to 10, the decoder 7 selects an output terminal at a position corresponding to the input count value, sets the level to "0" or "1", and then operates the steering wheel. It is configured to control an external device, such as a cornering lamp system, which operates in conjunction with each other. In this figure,
Only 7a is shown as the output terminal of the decoder 7, but UP
When the count value of the / DOWN counter 6 is ± 0, the output level of the output terminal 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". 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 reference clock generator 15 is input,
The processed signal is input to the third input terminal via the vehicle speed detection circuit 16. The vehicle speed detection circuit 16 includes resistors R1 to R8, capacitors C1 and C2, a diode D1, transistors Q1 and Q2, and a comparator CP, and 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 at "1" 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 the same as the progress counter 17 to
It is supposed to be input to 19 and this counter 17 to 19
The overflow signal (CARRY signal) is input to the second to fourth input ends of the 4-input OR gate 20. The "1" level output passing through the OR gate 20 is input as a reset signal to the counters 17-19. The CARRY signals sent from the counters 17 and 19 are also input to the set terminals of the flip-flops 31 and 32, and the Q outputs of the flip-flops 31 and 32 are the AND gates 33 and 32.
It is input to one end of 34 and one ends of OR gates 35 and 36. To the other ends of the AND gates 33 and 34, a "1" level signal generated at the output terminal 7a of the AND gates 33 and 34 is input, and the outputs of the AND gates 33 and 34 are 4-input OR gates 28. Is input to the first and second input terminals of the.
The CARRY signal sent by the counter 18 is the OR gate 2
It is to be input to the UP / DOWN counter 6 via 1, and the count value in the UP / DOWN counter 6 is reset and returned to ± 0 by the "1" level signal passing through this OR gate 21. Has become.

On the other hand, to the other ends of the AND gates 23 and 24, the comparison output sent from the comparator 22 is input, and the comparator 22 receives a predetermined voltage at the same time when the power is turned on to the terminal 103, 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 23 is the OR gate 21.
Is input to the other end of AND gate 24
The output of is input to the set terminal of the flip-flop 25,
The Q output of the flip-flop 25 is input to the "B" input terminal of the decoder 26. Decoder 26 “C”
The down signal and the up signal are input to the "D" input terminal through the UP / DOWN switching circuit 5, and the decoder 26 has its input terminals "D", "C",
When the signals "0", "1", "1", "1" are input to "B", "A", the level of the output terminal 26a is set to "1", "1", " When signals of "0", "1", and "1" are input, the level of the output terminal 26b is set to "1".
It is supposed to be. In addition, "D", "C",
When "B" and "A" are combinations other than those in Table 1, the levels of the output terminals 26a and 26b are both "0".

Then, the "1" level signals sent from the output terminals 26a and 26b of the decoder 26 are input to the third and fourth input terminals of the OR gate 28 and the other ends of the OR gates 36 and 35. The one-shot multivibrator (hereinafter simply referred to as "one-shot") 37 is activated by passing a signal of "1" level through the OR gate 28, and the one-shot signal transmitted by the one-shot 37 is UP / DOWN counter. 6 is input as the load signal. When the load signal is input and the “1” level signal is input to the encoder 29 through the OR gate 36, the outputs Q _{A to} Q _D of the encoder 29 at this time are captured. ,
The count value of the UP / DOWN counter 6 is set to +1. Further, when the load signal is input and the “1” level signal is input to the encoder 29 through the OR gate 35, the outputs Q _{A to} Q _D of the encoder 29 at this time are captured, UP / DOWN
The count value of the counter 6 is set to -1.

Note that the one-shot 30 is activated at the falling edge of the one-shot signal sent by the one-shot 37, and the one-shot signal sent by the one-shot 30 resets the flip-flops 25, 31, and 32. It has become a thing.

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 count value at counter 18 is integrated and goes up. In this case, UP / DOWN
Since the count value in the counter 6 has a long period of ± 0, the counter 18 out of the counters 17 to 19 overflows the earliest and sends out a CARRY signal of "1" level, and this CARRY signal causes the OR gate 21 to pass. It passes through and is input to the UP / DOWN counter 6, and the UP / DOWN counter 6 is reset to set the count value to ± 0. In this case, UP / DOWN
The count value of the 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 upper ideal origin position, the correction operation that is a feature of the present embodiment is promptly performed as follows, and the external device (for example, the irradiation direction of the headlight) can be smoothly operated. The variable cornering lamp system) can be controlled in conjunction with steering of the steering wheel.

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 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). ), 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 counter 17
The counter 17 overflows earliest out of 19 and sets the flip-flop 31 to the set state. The “1” level Q output sent from the flip-flop 31 is set in the encoder 29 via the OR gate 35. As a result, the outputs Q _{A to} Q _D of the encoder 29 are -1 (count value).
Is output (see Table 2). 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 33 is set to the flip-flop 31 ". The 1 ”level Q output passes, and the“ 1 ”level Q output passes through the OR gate 28 to activate the one shot 37, and the one shot signal sent by the one shot 37 is sent to the UP / DOWN counter 6. It is input as a load signal. The input of this load signal causes UP / DOWN6 to output the encoder 29 at this time.
Captures the Q _A to Q _D, sets changed to -1 to indicate the count value from ± 0 of Q _A to Q _D. As a result, the count value of the UP / DOWN counter 6 is -1 in the first subzone,
The second sub-zone becomes ± 0, the second sub-zone is quickly determined as the origin position, and the count value in the UP / DOWN counter 6 is corrected quickly.

Further, when the integration time in which the count value of the UP / DOWN counter 6 becomes -1 in the third subzone becomes long, the counter 19 out of the counters 17 to 19 overflows earliest, and the flip-flop 32 is set. . And
The "1" level Q output sent from the flip-flop 32 is set to the encoder 29 via the OR gate 36. As a result, the outputs Q _{A to} Q _D of the encoder 29 are +1.
The output state indicating (count value) is set (see Table 2). 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 34 and the flip-flop 32 " The 1 ”level Q output passes, and the“ 1 ”level Q output passes through the OR gate 28 to activate the one shot 37, and the one shot signal sent by the one shot 37 is sent to the UP / DOWN counter 6. It is input 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 29 at this time, and changes the count value from ± 0 to +1 which Q _{A to} Q _D indicates. To do. As a result, the count value in the UP / DOWN counter 6 becomes the first
+1 in the subzone and ± 0 in the third subzone,
Quickly determine the 3rd subzone as the origin position, and perform UP / DOW
The correction of the count value in the N counter 6 is promptly performed.

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 3) 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
Based on the comparison result of the comparator 8 that the count value in the counter is +1 or more, the counter 17 out of the counters 17 to 19 overflows earliest, and the flip-flop 31
Is set. And this flip-flop 31
The Q output of "1" level sent by is set to the encoder 29 via the OR gate 35. This allows the encoder
The outputs Q _{A to} Q _D of 29 are in an output state indicating -1 (count value) (see Table 2). 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, the count value of the UP / DOWN counter 6 is ±.
When it becomes 0, the "1" level Q output of the flip-flop 31 passes through the AND gate 33, and the "1" level Q output is generated.
The one-shot 37 is operated by the output passing through the OR gate 28, and the one-shot signal sent by the one-shot 37 is input to the UP / DOWN counter 6 as a load signal. Then, by inputting this load signal, UP / D
The OWN counter 6 outputs the outputs Q _{A to} Q _D of the encoder 29 at this time.
Uptake, indicating the count value from ± 0 of Q _A to Q _D -
Change the setting to 1. As a result, the UP / DOWN counter 6
The value of is −1 in the third subzone, ± 0 in the first subzone, and +1 in the second subzone (see Table 3).
After this, the flip-flop 31 is the one-shot 30
It is set by the one-shot signal sent by the.

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
Counters 17 to 19 based on the comparison result in
17 overflows earliest and puts flip-flop 31 in the reset state. Then, based on the "1" level Q output sent from the flip-flop 31, at the time when the count value in the UP / DOWN counter 6 becomes ± 0, the count value is changed to -1. Will be done. As a result, the value of the UP / DOWN counter 6 is -2 in the third subzone, -1 in the first subzone, and the second in the second subzone.
It becomes ± 0 in the subzone (see Table 3).

After that, during the generation period of the origin range detection signal of "1" level,
The integration time at which the count value becomes ± 0 in the UP / DOWN counter 6 becomes long, and in this way, the determination result of the origin position is updated from the third subzone to the second subzone via the first subzone. Become so.

That is, when the origin position is updated all at once from the third sub-zone to the second sub-zone, the variable position in the irradiation direction of the headlamp based on the count value of the UP / DOWN counter 6 also suddenly changes. 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 in the sub-zone, 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 22 continues to be "1" for a predetermined time.
When the power is turned on while the “1” level origin range detection signal is being input via the terminal 101, the “1” level comparison output sent from the comparator 22 causes the AND gate 23 to output. Pass and UP via ORGATE 21
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 24 via the inverter 27, and the "1" level comparison output of the comparator 22 passing through the AND gate 24 causes Flip flop 25
Is set. As a result, the “B” of the decoder 26
The "1" level Q output of the flip-flop 25 is set to the input terminal. When the "1" level origin range detection signal is input via the terminal 101 by the subsequent steering of the steering wheel, this "1" level origin range detection signal is input to the "A" input terminal of the decoder 26. Will be set. 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 / DOW associated with the right steering is performed.
By setting the "1" level up signal from the N switching circuit 5 to the "D" input terminal of the decoder 26, "D", "C",
"B" and "A" become "1", "0", "1", "1", and the level of the output terminal 26b of the decoder 26 becomes "1" level (see Table 1). The "1" level signal from the output terminal 26b of the decoder 26 is UP / DOWed via the OR gate 28.
It is given to the N counter 6 as a load signal. Upon receiving this load signal, the UP / DOWN counter 6 receives the encoder 29
Capture the outputs Q _{A to} Q _D of. At this time, the output of encoder 29
Q _A to Q _D, the output terminal 26a of the decoder 26 is "0", because 26b is "1" level, that is, the output of the OR gate 36 is "0", the output of the OR gate 35 is "1" level , -1 (count value) are shown (see Table 2). As a result, the count value of the UP / DOWN counter 6 is −
It is set to 1, that is, −1 in the third subzone, ± 0 in the first subzone, and +1 in the second subzone, and the first subzone of 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 26 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 26a of the decoder 26 becomes "1" level (see Table 1). The "1" level signal from the output terminal 26a of the decoder 26 is given to the UP / DOWN counter 6 as a load signal via the OR gate 28. Upon receiving this load signal, the UP / DOWN counter 6 takes in the outputs Q _{A to} Q _D of the encoder 29. At this time, the encoder output Q _A ~
In Q _D , output terminal 26a of decoder 26 is "1", 26b is "0"
Since it is the level, that is, the output of the OR gate 36 is "1" and the output of the OR gate 35 is "0" level, +1 (count value) is shown (see Table 2). 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 the present embodiment, when the origin zone is divided into a plurality of sub-zones, the decomposition is performed with 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 with such a fine division, the integrated time that contributes to the detection of the origin range is By determining the sub-zones adjacent to each other in the sub-zone direction that reach the predetermined time as the tentative origin position, it is possible to shift the origin position one by one to the adjacent sub-zones and gradually approach the true origin position for each sub-zone. 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 needless to say, it can be realized by a software technique using a microcomputer light. 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 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 that contributed to the detection of the origin range of each of the divided sub-zones is added up. An origin position determining means for determining a subzone that has reached a predetermined time as an origin position is provided, and when updating the determination result of the origin position, the integrated time is adjacent to the subzone direction that reaches the predetermined time earliest. Since it is determined as the origin position of the sub-zone, if the origin position before the determination and the origin position after the determination are not adjacent to each other, shifting the origin position one by one to the adjacent sub-zone It becomes possible to asymptotically approach the true origin position. For example, when this rotating body is rotated in conjunction with the vehicle steering wheel operation, 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, 31,32
……flip flop.

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 rotation position detecting means that detects a rotation angle 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 sub-zones is integrated, and the sub-zone that reaches the predetermined time as soon as this integrated time is determined as the origin position. Point position determining means, and when the determination result of the origin position is updated, a subzone adjacent to the subzone direction in which the integrated time reaches a predetermined time earliest is determined as the origin position. A device for determining the origin position of a rotating body.