JPH01250714A - Apparatus for judging origin position of rotary body - Google Patents

Abstract

PURPOSE:To accurately judge a steering neutral position by a simple constitution, by judging sub-zone, which is adjacent in a sub-zone direction wherein the integration time contributing to the detection of an origin position becomes max. within a predetermined time when the judge result of the origin position is renewed, as the origin position. CONSTITUTION:A steering angle sensor 100 is constituted of a rotary disc 1 and photointerrupters 2-4 and slits 1a are opened to the disc 1 at a predetermined angular pitch P and a slit 1b as an origin zone is opened thereto. The rotary position wherein the slit 1b is opposed to the photointerrupter 4 is set to the origin position of the disc 1 and the angle with alpha of the slit 1b is set to the three-angular pitch P of the slits 1a and, when the origin zone is divided into many sub-zones according to the steering angle position detected by the sensor, the origin position can be accurately judged. When this judge result is renewed, the times contributing to the detection of the respective origin ranges of the divided sub-zones are integrated and the sub-zone adjacent in a sub-zone direction wherein said integration time becomes max. within a predetermined time is judged as the origin position. By this method, the origin position, that is, a steering neutral position can be accurately judged.

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 steering wheel steering, and two photoink laminations are placed at the passing positions of the slits. They are placed adjacent to each other and perform various controls linked to steering wheel operation.

In other words, the first and second
A pulsed electrical signal with the same waveform but approximately 90° out of phase (two-phase incremental signal)
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, so in order to detect the origin position, an origin slit is provided in the rotating disk, and this origin slit is connected to the third photo ink club. The system uses a 3-bit configuration in which an origin signal is obtained by passing, 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, when 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 several tens of thousands in the worst case. For this reason, in order to obtain the origin signal, the angular width of the origin slit provided in the rotating disk is usually expanded, and even if there is an assembly error of several 10 @, as long as the vehicle is traveling straight, the origin It is assumed that the signal can be obtained.

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 Based on this, the origin zone is divided into a plurality of subzones, the time that each of the divided subzones contributes to detecting the origin range is accumulated, and the subzone in which this accumulated time is the maximum within a predetermined time is determined to be the origin position. and an origin position determination means, and when updating the determination result of the origin position, the subzone adjacent to the subzone direction in which the accumulated time is the maximum within a predetermined time is determined as the origin position.

[Effect]

Therefore, according to the present invention, if the origin position before determination and the origin position after determination are not adjacent subzones, the origin position is shifted to the adjacent subzones one by one, and the true origin position is adjusted for each subzone. It becomes possible to asymptote.

〔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.
The /DOWN switching circuit 6 is an UP/DOWN counter that receives the processed signal sent out from the UP/DOWN switching circuit 5.

The steering 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). Photointerrupters 2 and 3 are arranged adjacent to each other at the passing position of this slit 1a, and this photointerrupter 2
and 3, by passing through the slit 1a as the rotating disk l rotates, the "
Pulsed electrical signals having the same waveform and alternating 1 and 0 levels are generated. In other words, from the steering condition shown in Figure 2, if you turn the steering wheel clockwise (clockwise in Figure 2), N
When an electrical signal in the positive direction centered at the point rotates counterclockwise, an electrical signal in the negative direction centered at the N point is generated. The electrical signal generated in the photo-interrupter 2 is 90'' in phase ahead of the electrical signal generated in the photo-interrupter 3, and is at the origin position (steering neutral position) of the rotating disk l, which is ideal in design. At point N shown in FIG. 3, the electrical signal generated in the photoinkrater 2 is in the falling or rising period when it changes from the "1" level to the "0" level or from the "0" level to the rlJ level, The electrical signal generated in the photo ink converter 3 is at the "0" level. and,
The electrical signals sent out by the photo ink converters 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 provided independently as an origin zone, and passage through this slit 1b is detected by a photo ink printer 4. That is, slit lb
The rotational position facing the photointerrupter 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 misalignment of the serrations between the steering shaft and the steering wheel, the steering shaft and the steering wheel. The setting is set to exceed the worst-case assembly error, which takes into account installation tolerances with the sensor, poor wheel alignment, etc. In this embodiment, the angular width α of the slit 1b is set to 60'', and the inventor's investigation revealed that the angular width α of the slit 1b is 54° for the above-mentioned assembly error paste case.
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 man power and gate 14. and gate 3
9. rAJ input terminal of decoder 44 and inverter 41
The information is manually input to the AND gate 40 via the . Here, the photo ink club 4 is located at the origin position which is ideal in the design of the rotating disk 1, that is, at the N shown in FIG.
The point is located at the center of the angular width α of the sulin 1-1b. 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 pulsed electric signal and sends out a number of up and down signals according to the amount of right and left steering of the steering wheel. The UP/DOWN counter 6 counts up or down its count value by the number of input amplifier signals or down signals.

In other words, the currant value in the UP/DOWN counter 6 is basically determined based on the origin position which is ideal in the design of the rotary disk 1, and the count value is changed to the photo in club by the right steering wheel. It is designed to increase sequentially at each falling edge of the output of the data controller 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 photo ink converter 2. That is, in Figure 3,
If you turn the handle clockwise from point N, a
The count value of the UP/DOWN counter 6 increases to +1 at point B, and increases to +2 at point b, and if the rotation is made to the left from point N, the count value of the UP/DOWN counter 6 increases to - at point 0. 1 and then -2 at point d. The count value of the UP/DOWN counter 6 is input to a decoder 7 and digital comparators 8 to 10, and the decoder 7 selects an output terminal at a position corresponding to the input count value and selects the output terminal at a position corresponding to the input count value. The level is set to "O" or "1" to control external equipment, such as a cornering lamp system, which is operated in conjunction with steering wheel steering. Although only the output terminal 7aL of the decoder 7 is shown in this figure, when the count value in the UP/DOWN counter 6 is +0, the output level of this output terminal 7a is "1".
”.

A predetermined comparison reference value is set in each of the comparators 8 to 10, and the comparison reference value and the count value input via the uP/DOWN counter 6 are compared here. That is, the comparator 8 has U
+1 as the count value at P/DOWN counter 6
is set as the right 1-bit reference value, and -1, which is the count value of the UP/DOWN counter 6, is set in the comparator 1o as the left 1-bit reference value. The comparator 9 is set to ±O as a center reference value based on the count value of the UP/DOWN counter 6, and when the count value input via the UP/DOWN counter 6 is +0, the output level of the comparator 9 becomes rlJ. Also, U
When the count value input via the P/DOWN counter 6 is greater than or equal to +1 (≧1), the output level at the comparator 8 becomes “1”, and the count value input via the UP/DOWN counter 6 becomes 11. When the following (≦1) is satisfied, the output level of the comparator IO becomes "1". Then, the signals of the rlJ level sent out from the comparators 8 to 1O are
It is input to one end of the AND gate 1
The output of the AND gate 14 is input to the other ends of the gates 1 to 13. As mentioned above, the origin range detection signal is inputted to the first input terminal of the AND gate 14 via the photo ink converter 4 shown in FIG. has a reference clock generator 15
A clock signal sent out by the vehicle speed detection circuit 16 is input to the third input terminal, and a processed signal thereof is input to the third input terminal via the vehicle speed detection circuit 16. Vehicle speed detection circuit 16
are resistors R1 to R8, capacitors C1 and C2, diode D1, transistors Ql and Q2, and comparator C
P, and when the vehicle speed increases based on the vehicle speed signal input through the terminal 102, the ant game)
The output of comparator CP to 14 is at the "1" level. That is, while the vehicle is stopped, the output of the comparator CP is at the "0" level.

On the other hand, the outputs of the AND gates 11 to 13 are sent to the counter 17.
~19, and the count value in each counter is one-shot multi-by-break (
The latch circuits 21 to 2
It is now being incorporated into 3. Then, the count values taken into the launch circuits 21, 22 and 23 are
The digital comparators 24 to 26 are manually input to predetermined input terminals. That is, the latch circuit 21
．． If the count values taken into 22 and 23 are α1β and γ, respectively, the count value α sent out from the latch circuit 21 is sent to the non-inverting input terminals of the comparators 24 and 26, and the count value β sent out from the latch circuit 22 is sent to the non-inverting input terminals of the comparators 24 and 26. It is input to the inverting input terminal and the non-inverting input terminal of the comparator 25, and the latch circuit 2
The count value T sent by 3 is the comparator 25 and 2
It is designed to be input to the inverting input terminal of No. 6. The outputs of the comparators 24 to 26 are input to input terminals 27a to 27c of a decoder 27, and the decoder 27 outputs terminals 27d to 27i based on the combination of signals input to the input terminals 27a to 27c. A predetermined terminal is selected from among them, and the output level of that terminal is set to "1". Table 1 shows the truth table of decoder 27.
and are shown separately in Table 2.

That is, depending on the magnitude relationship of the count values α, β, and T taken into the launch circuits 21, 22, and 23, “1” is determined.
” level is determined as shown in Table 2, and output terminals 27d to 27i
The signals sent from the gates are manually inputted to one end of the Nantes gates 28-33. And Nantes Gate 2
8 and Table 1 Table 2 The output of AND gate 13 is branched and inputted to the other end of 29, and Nant gates 30 and 33
The output of the AND gate 12 is branched and inputted to the other end, and the AND gate 1 is input to the other end of the Nant gates 31 and 32.
The output of 1 is branched and inputted. The outputs of the Nante gates 28 and 29 are input to the Nante gate 47, the outputs of the Nante gates 30 and 33 are input to the Nante gate 48, and the outputs of the Nante gates 31 and 32 are input to the Nante gate 49. The outputs of gates 47 and 49 are input to one end of AND gates 34 and 35 and one end of OR gates 51 and 50.

The "1" level signal generated at the output terminal 7a of the AND gates 34 and 35 is inputted via the decoder 7 to the other ends of the AND gates 34 and 35, and the outputs of the AND gates 34 and 35 are connected to the four-man OR gate 60. The signal is input to the first and second input terminals of the. Then, the output of the Nantes gate 48 is UP/DO via the OR gate 61.
It is input to the WN counter 6, and by the rlJ level signal passing through this OR gate 61, the U
The count value in the P/DOWN counter 6 is reset and returned to ±0.

Furthermore, the one-shot 36 is activated based on the one-shot signal sent out by the one-shot 20.
The one-shot signal sent by the one-shot 36 serves as a reset signal for returning the count values of the counters 17 to 19 to zero. The one shot 20 is an overflow signal (CARRY signal) sent by the ring counter 37.
It operates based on the latch circuit 21~
23 is repeatedly sent out at predetermined time intervals. Note that the comparison output of the comparator CP in the vehicle speed detection circuit 16 is stored in the counter 37 as rl.
While at J level, the clock signal sent from the reference clock generator 15 is inputted via the AND gate 38.

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 comparison output is immediately set to the rlJ level, and based on the increase in the charge level to the capacitor C3, the comparison output is set to the rlJ level after a predetermined time delay.
0'' level. and,
The output of the AND gate 39 is input to the other end of the OR gate 61, the output of the AND gate 40 is input to the set terminal of the flip-flop 43, and the Q output of the flip-flop 43 is input to the rBJ input terminal of the decoder 44. It is supposed to be input to . A down signal and an up signal are input to the rCJ and "D" input terminals of the decoder 44 via the UP/DOWN switching circuit 5, and the decoder 44 has 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 The "1" level signals sent from the output terminals 44a and 44b of the decoder 44 are manually inputted to the third and fourth input terminals of the OR gate 60 and the other terminals of the OR gates 51 and 50. , the one-shot 52 is actuated by the rlJ level signal passing through the OR gate 60, and the one-shot signal sent by this one-shot 52 becomes UP/
This signal is input to the DOWN counter 6 as its load signal. When this load signal is input, if an rlJ level signal is input to the encoder 46 after passing through the OR gate 51, the count value in the UP/DOWN counter 6 increases by +1 based on the output state of the encoder 46. It is set to .

Furthermore, when the load signal is input, if a signal at the rlJ level is input to the encoder 46 after passing through the OR gate 50, based on the output state of the encoder 46,
The count value in the DOWN counter 6 is set to -1. In addition, one shot 52
The one-shot 53 is activated at the falling edge of the one-shot I signal sent by the one-shot I signal, and the one-shot signal sent by the one-shot 53 resets the latch data in the flip-flop 43 and the latch circuits 21 to 23. It has become something that

Next, the operation of the device configured in this way will be explained. That is, if the car is now traveling straight and the rotating disc l is located at the ideal design origin position as shown in FIG. 2 in the true straight steering position, then While the origin range detection signal at the "1" level is being input, the period in which the count value in the 11'/DOWN counter 6 is +0 becomes long. That is, the count value in the IIP/DOWN counter 6 is
At the same time as input to decoder 7, comparators 8 to lO
It is also input to the comparators 8 to 1O and compared with each reference value. When the count value in the UP/DOWN counter 6 is +1 or more, the comparator 8
When a J level signal is sent and the count value in the UP/DOWN counter 6 is less than 11, the comparator l
O sends out a "1" level signal.

Further, when the count value in the UP/DOWN counter 6 is +0, the comparator 9 sends out a signal at the rlJ level. Then, rl sent from comparator 8 to IO
Based on the J level signal, while the rlJ level origin range detection signal is input through the terminal 101, the clock signal from the reference clock generator 15 that passes through the AND gate 14 passes through the AND gates 11 to 13. and input to counters 17-19. That is, UP/DOWN
When the count value in the counter 6 is +1 or more, the count value in the counter 17 is integrated and incremented, and U
When the count value in the P/DOWN counter 6 is less than 11, the count value in the counter 19 is integrated and incremented. Further, when the count value in the UP/DOWN counter 6 is +0, the count value in the counter 18 is integrated and incremented. The count value in each counter is determined by the launch circuit 21 due to the falling edge of the one-shot signal sent by the one-shot 20.
~23. On the other hand, after the count value has been taken in, the counters 17 to 19 are reset by the one-shot signal sent by the one-shot 36, and the count value is returned to zero, in preparation for counting the next input clock signal. . In other words, counter 17~
19 counts clock signals input within a predetermined time (in this embodiment, this time is 1 minute) determined by the output cycle of the CARRY signal sent out by the counter 37, and sends the count to the launch circuits 21 to 23. The count values counted by the counters 17 to 19 within this predetermined time are held.

Thus, the count values (α, β and T) taken into the launch circuits 21, 22 and 23 are sent to the comparators 24 to 23.
26 will be used for comparison. In this case, UP/
Since the count value in the DOWN counter 6 remains +0 for a long period of time, the count value β held by the launch circuit 22 among the launch circuits 21 to 23 becomes the maximum, and the decoder 27 uses the count value in the latch circuits 21, 22 and 23. Depending on the magnitude of the value, the output terminal 27f
Alternatively, the ``1'' level signal will be transmitted from 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 Nant gates 30 and 33 become "1" level, and the output level of the Nant gate 48 becomes rlJ. Then, a reset signal is input to the UP/DOWN counter 6 via the OR game 61, and the count value becomes +0. That is, the IIP/DOWN counter 6 is reset at the time when the clock signal is inputted via the AND gate 12 to the counter 18 that performs the maximum count within a predetermined time. In this case, the count value in the UP/DOWN counter 6 is already +0, so the count value in the IIP/DOWN counter 6 is +0.
It will continue to be 0.

The above-mentioned operation has been explained assuming that when the automobile is traveling straight, the rotary disk 1 is located at the ideal origin position in its design at the true straight-ahead steering position, but due to the assembly error, the rotary disk 1 is In the case where the origin position is deviated from the ideal position, the correction operation, which is a feature of this embodiment, is quickly performed as described below, and the external equipment can be controlled in conjunction with the steering wheel steering without any trouble. It becomes something you get.

That is, when the rotating disk 1 is at the original position which is ideal in terms of design, 1. 22(
b) When the range up to the point is taken as the origin zone in the slit 1b, within the region from point 0 to point a that divides this origin zone (hereinafter, this region is referred to as the first subzone), while traveling straight, The time period during which the count value in the UP/DOWN counter 6 maintains +0 becomes longer. However, if the rotating disk 1 deviates from the ideal design origin position due to assembly errors, while traveling straight,
The period during which the count value of the UP/DOWN counter 6 maintains +1 or =1 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 cumulative time for which the count value in the UP/DOWN counter 6 becomes +1 or -1 becomes longer.

When the cumulative time during which the count value in the UP/DOWN counter 6 becomes +1 within the second subzone becomes longer, the count value α held by the latch circuit 21 among the launch circuits 21 to 23 becomes the maximum, and the output terminal 27g of the decoder 27
From 27h onwards, a "1" level signal is transmitted. 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 Nant gates 31 and 32 become rlJ level, and the Nant gate 49
When the output level of the output terminal 7a of the decoder 7 becomes "1", this "L" level output is set to the encoder 46 via the OR gate 50, and the level of the output terminal 7a of the decoder 7 becomes "1", that is, the UP/ When the count value in the DOWN counter 6 becomes +0, the "1" level output of the Nants gate 49 passes through the AND gate 35, and this "1" level output passes through the OR gate 60 by 1ltl, resulting in a one-shot 52. As a result of this operation, a load signal is input to the UP/DOWN counter 6. Then, by inputting this load signal, the encoder 4 at this time
Based on the output state of UP/DOWN counter 6, the count value of UP/DOWN counter 6 is changed from +0 to -1. That is, the count value in the tlP/DOWN counter 6 becomes -1 in the first subzone and +0 in the second subzone, the second subzone is quickly determined as the origin position, and the count value in the UP/DOWN counter 6 is corrected. will be carried out promptly.

Furthermore, as the cumulative time during which the count value in the UP/DOWN counter 6 becomes -1 within the third subzone becomes longer, the count value T held by the launch circuit 23 among the launch circuits 21 to 23 becomes the maximum, and the decoder 27 output terminals 27d and 27e begin to output "L" level signals. Then, when the clock signal passes through the AND gate 13, that is, when the third subzone among the three subzones is detected, the other ends of the Nant gates 28 and 29 become rlJ level, and the Nant gate 47 reaches the rlJ level. When the output level becomes "1", this "1" level output is set to the encoder 46 via the OR gate 51, and when the count value in the UP/DOWN counter 6 becomes +0, the AND gate 34 is changed to a Nants gate. The rlJ level output of 47 passes through, and the rN level output passes through the OR gate 60 to activate the one shot 52, so that a load signal is input to the UP/DOWN counter 6. By inputting this load signal, the count value in the UP/DOWN counter 6 is changed from +0 to +1 based on the output state of the encoder 46 at this time. That is, the count value in the UP/DOWN counter 6 is +1 in the first subzone and ± in the third subzone.
0, the third subzone is quickly determined to be the origin position, and the count value in the UP/DOWN counter 6 is quickly corrected.

Furthermore, in this embodiment, special driving conditions such as driving on a road surface with a large slope to the left or right are taken into account, and in this case, the determination result of the origin position is updated rapidly between distant subzones. In order to prevent this, the count value of the UP/DOWN counter 6 is corrected as follows. In other words, for example, if we have now obtained a determination result that the origin position is within the third subzone, then as the steering wheel is turned, the UP/
The count value in the DOWN counter 6 is +0 in the third subzone, +1 in the first subzone, and +2 in the second subzone. In such a state, based on the above-mentioned special running state, it is assumed that the cumulative time during which the count value of the UP/DOWN counter 6 becomes +2 becomes longer during the generation period of the origin range detection signal of the "1" level. The count value in UP/DOWN counter 6 is +
Based on the comparison result of the comparator 8, which is 1 or more, the count value α held in the launch circuit 21 among the latch circuits 21 to 23 becomes the maximum, and the Nant gate 49
The output becomes "1" level. Based on the “1” level signal passing through this Nantes gate 49, the UP/
When the count value in the input counter 6 reaches ±O, the count value is changed to -l. As a result, the value of IJP/DOWN counter 6 is -11 in the third subzone, +0 in the first subzone, and +0 in the second subzone.
+1 in the subzone.

As a result, during the generation period of the rlJ level origin range detection signal, the cumulative time for the count value of the UP/DOWN counter 6 to reach +1 becomes longer, and based on the comparison result of the comparator 8, the latch circuit is again The count value α held at 21 reaches the maximum, and the output of the Nant gate 49 becomes the "1" level again. Then, based on the rlJ level signal passing through the Nantes gate 49, the count value in the UP/DOWN counter 6 increases to +0.
At the point in time, the count value is set to -1. As a result, the value of the leaf/DOWN counter 6 is -2 in the third subzone and -1 in the first subzone.
, +0 in the second subzone. Thereafter, during the generation period of the origin range detection signal at the "1" level, the cumulative time for the count value of the UP/DOWN counter 6 to reach +0 becomes longer, and the count value β held by the launch circuit 22 reaches the maximum. In this way, the determination result of the origin position is updated from the third subzone to the first subzone to the second subzone. That is, the third
If the origin position is updated all at once from the sub-zone to the second sub-zone, the variable position of the headlight irradiation direction based on the count value of the UP/DOWN counter 6 will change rapidly, causing the driver to This results in confusion. In contrast, in this embodiment, if the origin position before the determination and the origin position after the determination are not in adjacent subzones, the origin position is updated in one step. A sudden change in the irradiation direction of the light does not occur.

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 that the clock signal from the reference clock generator 15 can pass through the AND gate 14 and the origin position. Part 1~
The time contributing to the detection of the origin range of the third subzone is
The counters 17 to 19 do not integrate.

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, so when the power is turned on while the origin range detection signal of the rlJ level is input through the terminal 101, the comparison output of the “1” level sent out by the comparator 42 passes through the AND gate 39. Or Gate 61
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 The comparison output of the comparator 42 which passes through the analogue 40 causes the flip-flop 43 to enter the cent state. As a result, the rlJ level Q output of the flip-flop 43 is set to the rBJ input terminal of the decoder 44. Then, when the origin range detection signal of the "1" level is inputted via the terminal 101 by subsequent steering wheel steering, this "1" level
The level origin range detection signal is set to the "A" input terminal of the decoder 44. Now, suppose that the origin range detection signal of level "1" is generated due to the clockwise rotation of the rotary disk l accompanying the right steering.
At this point, the output terminal 44b of the decoder 44 becomes ``1'' level due to the setting to the rDJ input terminal of the decoder 44, and the UP/DOWN counter 6 The count value at −
1, and the third subzone among the three subzones is set as the initial origin position. Furthermore, if it is assumed that the origin range detection signal of the "1" level is generated due to the left rotation of the rotary disk l accompanying the left steering, then the [
By setting the down signal of level 11 from the IP/DOWN switching circuit 5 to the rCJ input terminal of the decoder 44, the level of the output terminal 44a of the decoder 44 becomes "1" at this point.
” level, the count value in the IP/DOWN counter 6 is set to +1, and the second subzone among the three subzones is set as the initial origin position.

In addition, in this 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 integral multiple of this minimum resolution. Furthermore, when the subzones are set to an integral multiple of the minimum resolution, each subzone may have a mutually overlapping portion.

Furthermore, in this embodiment, the angular width α of the slit 1b is
is set to be slightly wider than the 3-angle pitch of the support slit la, but the angular width may be set at least wider than the 2-angle pitch of the slit 1a.By doing this, the steering angle detected by the steering angle sensor Based on location
The origin zone can be divided into multiple subzones,
It becomes possible to accurately determine the origin position within the origin zone whose width has been expanded.

Furthermore, in this embodiment, the origin zone is divided into three parts, but it may be divided into even smaller parts. By determining the subzone adjacent to the maximum subzone direction within time as the temporary origin position, the origin position is shifted to adjacent subzones one by one, and asymptotically approaches the true origin position for each l subzone. It goes without saying that it can be done.

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) filed by the present applicant. is narrow, so the purpose of this embodiment cannot be achieved.

In addition, in this embodiment, the determination of the neutral steering position in a vehicle was explained as an example, but this is not limited to vehicles only, and can be applied to determination of the origin position of various rotating bodies that rotate in conjunction with external operations. It is suitable for application, and it is possible to perform various controls based on this determined origin position,
Its utility value is extremely high. Furthermore, in the above embodiment, the device for determining the origin position of the rotating body is configured in 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. .

〔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; an 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 a rotation angle detected by the rotational position detection means while the origin range is being detected by the origin range detection means. The origin zone is divided into a plurality of subzones based on the position, the time that each of the divided subzones contributes to the detection of the origin range is accumulated, and the subzone in which this accumulated time is the maximum within a predetermined time is determined as the origin position. When updating the determination result of the origin position, the subzone adjacent to the subzone direction in which the accumulated time is the maximum within a predetermined time is determined as the origin position, so that the If the origin position and the determined origin position are not adjacent subzones, it is possible to shift the origin position one by one to the adjacent subzones and asymptotically approach the true origin position for each l subzone. When the rotating body is rotated in conjunction with the vehicle's steering wheel operation,
It becomes possible to accurately and quickly determine the steering neutral position with a simple circuit configuration.

[BRIEF DESCRIPTION OF THE DRAWINGS] 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, and Fig. 2 is a schematic configuration diagram showing a steering angle sensor used in this device. FIG. 3 is an output waveform diagram of this steering angle sensor. 1... Rotating disk, 1a... Slit, tb... Slit, 2, 3.4... Photo ink club, 5...
- Kano/DOWN switching circuit, 6... Kano ZDOWN counter, 8-10... Comparator, 15... Reference clock generator, 17-19... Counter, 21-23
... Launch circuit, 24-26 ... Comparator, 2
7...Decoder, 37...Ring counter. Patent applicant: Koito Manufacturing Co., Ltd.

Claims (1)

[Claims] It has a slit zone provided at a predetermined angular pitch on its outer peripheral surface and an origin zone provided with an angular width wider than the two angular pitches of this slit zone, and rotates clockwise and counterclockwise in conjunction with external operation. a rotational body that detects a rotational angular position of the rotational body based on the passage of the rotational body through a slit zone, and a rotational position detection means that detects the rotational angular position of the rotational body based on the passage of the rotational body through the origin zone; an origin range detection means; and while the origin range is being detected by the origin range detection means, the origin zone is divided into a plurality of subzones based on the rotational angle position detected by the rotational position detection means; and an origin position determining means for accumulating the time contributed to the detection of each origin range and determining the subzone where the accumulated time is the maximum within a predetermined time as the origin position, and when updating the determination result of the origin position. An apparatus for determining an origin position of a rotating body, characterized in that a subzone adjacent to the subzone in the subzone direction in which the accumulated time is maximum within a predetermined time is determined as the origin position.