JPH0355333B2 - - Google Patents

Abstract

PURPOSE:To improve the extent of control accuracy, by making a position, which will not detect another zero position during a while the specified time elapses, after zero position detection, among zero positions situated at every rotation of a rotor rotating in linkage with steering wheel operation, judge as a rotational center position. CONSTITUTION:A rotational position sensor consists of a rotating disc 1 rotating in linkage with steering wheel operation and photointerrupters 2-4 set up as adjoined to a passing position of a slit 1a and a zero position detecting slit 1b installed in a peripheral edge of the said disc 1 at an equiangular interval. Each pulse signal out of these photointerrupters 2 and 3 is inputted into counters 6 and 7 via an UP/DOWN electronic switch 5, while a zero position detecting signal is inputted into AND gates 10 and 12. And, among zero positions situated at every rotation of the rotating disc 1, a zero position, which will not detect another zero position during a while the specified time elapses, after zero position detection, is judged as a rotational center position, for example, each lighting direction of headlights is controlled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is suitable for determining the center position of a rotating body that rotates in conjunction with steering wheel steering of a vehicle, etc. It is about the method.

[Conventional technology]

Conventionally, in vehicles such as automobiles, a plurality of slits are formed at equal angular intervals on a rotating disc that rotates in conjunction with steering wheel steering, and two photo interrupters are placed adjacent to each other at the positions where these slits pass. The system performs various controls linked to the steering wheel.

That is, in conjunction with steering wheel steering, a pulsed electrical signal having the same waveform but with a phase difference of approximately 90° is generated in the first and second photointerrupters;
By counting these electrical signals, the rotational direction and rotational position of the handle are detected.

[Problem that the invention seeks to solve]

However, with such conventional rotational position detectors, if the counter miscounts due to electrical noise, etc., there is no means to correct the error, and as the error accumulates, the system There was a problem that malfunctions occurred.
In addition, if a method is used to cut off the power supply to the rotational position detector after the ignition switch is turned off in order to reduce power consumption, the rotational position of the handle until the next ignition switch is turned on is Changes resulted in errors that were accumulated.

[Means for solving problems]

The present invention has been made in view of the above-mentioned problems, and has a predetermined rotational angle position of a rotating body that rotates clockwise and counterclockwise in conjunction with steering wheel steering as the origin position. Among the origin positions located at , the origin position where no other origin position is detected until a predetermined time has elapsed after the origin position was detected is determined as the rotation center position of the rotating body.

[Effect]

Therefore, according to the present invention, an origin position where no other origin position can be detected until a predetermined time has elapsed after the origin position is detected can be determined as the rotation center position of the rotating body.

〔Example〕

Hereinafter, the method for determining the center position of a rotating body according to the present invention will be explained in detail. FIG. 1 is a block diagram showing an embodiment of this center position determination method. In the same figure, 5 is an UP/DOWN switching circuit which inputs the pulsed electric signal sent out by the rotational position detection sensor (Fig. 2) and sends out processed signals (UP signal and DOWN signal) according to the steering wheel steering, and 6 and 7 are first and second circuits that receive the processed signal sent out from this UP/DOWN switching circuit 5.
UP/DOWN counter, 8 is a decoder that selects an output terminal (not shown) at a position corresponding to the count value counted by counter 6, and sets the level to "L" or "H"; 9 is a decoder of this decoder 8; This is a lamp drive circuit that changes the irradiation direction of a headlamp (not shown) depending on the output state.

The rotational position detection sensor shown in FIG.
and photo interrupters 2 to 4 each having a light-emitting element and a light-receiving element. It is arranged adjacent to the passage position of the slit 1a. Then, as the rotating disk 1 rotates and passes through the slit 1a, a pulsed electrical signal having the same waveform but with a phase shift of approximately 90° is generated in the photointerrupters 2 and 3. The electrical signal is input to the UP/DOWN switching circuit 5. Further, a slit 1b for detecting the origin position is independently provided at a predetermined rotational angle position on the outer peripheral edge surface of the rotating disk 1, and a photo interrupter 4 detects passage through the slit 1b. ing. That is, slit 1b
The rotational position facing the photo interrupter 4 is the origin position of the rotary disk 1, and this origin position is set in correspondence with the steering wheel steering position (hereinafter, this steering position will be referred to as the steering wheel center) when driving straight. ing. In other words, at the handle center, the rotating disk 1 is located at the origin position as shown in the figure (hereinafter, this position will be referred to as the rotation center of the rotating disk), and the handle centering on the handle center. The origin position of the rotating disk 1 changes with each rotation in the clockwise and counterclockwise directions.
It is now detected with a 360° shift. In general, the steering wheel of an automobile can be rotated less than two turns each clockwise (hereinafter referred to as rightward direction) and counterclockwise (hereinafter referred to as leftward direction) around the center of the steering wheel.
Therefore, the photo interrupter 4 detects a total of three origin positions including the rotation center, and when detecting this origin position, an "H" level is output to one of the input terminals of the AND gate 10 in FIG. An origin position detection signal is input.

On the other hand, the UP/DOWN switching circuit 5 processes the input pulsed electrical signals and sends out a number of up and down signals corresponding to the amount of right and left steering of the steering wheel. UP／
The DOWN counters 6 and 7 are configured to up-count or down-count their count values by the number of input up signals or down signals. In other words, when the rotating disk is at the rotation center position, the UP/DOWN
The count value in the counter 6 is set to zero, and when the steering wheel is turned to the right, the count value increases sequentially, and when the steering wheel is steered to the left, the count value decreases sequentially. And this
The count value sent by the UP/DOWN counter 6 is input to the decoder 8, and the lamp drive circuit 9 operates based on the output state of the decoder 8, so that the irradiation direction of the headlight is controlled in conjunction with steering wheel steering. It's getting old. It goes without saying that the UP/DOWN counter 7 also sequentially increases its count value by turning the steering wheel to the right, and decreases the count value by turning the steering wheel to the left. When the signal reaches the "H" level, the count value in the counter 7 is reset and returns to zero.

On the other hand, the output of the RS flip-flop circuit 11 is input to the other input terminal of the AND gate 10, and the output of the AND gate 10 is input to the S input of this flip-flop circuit 11 as a set signal. It's becoming like that.
The Q output of the flip-flop circuit 11 is input to one end of AND gates 12 and 13, and the clock pulse signal sent from the reference clock generator 14 is input to the other end of the AND gate 13. It's summery. Further, the origin position detection signal inputted to the AND gate 10 is branched and inputted to the other end of the AND gate 12, and the output of the AND gate 12 is inputted to the enable terminal of the comparator 15. It's becoming like that. Then, the comparator 15 is
When an "H" level signal is input to this enable terminal, the current count value of the UP/DOWN counter 7 is taken in and compared with the standard comparison count value N ₀ = 0, and the taken count value is If the value does not match the reference comparison count value _N0 , a reset signal is sent to the frequency divider 16. The clock pulse signal passing through the AND gate 13 is input to the frequency divider 16, and every time this clock pulse signal is input for 30 seconds or more, it overflows and is loaded into the UP/DOWN counter 6. It is designed to send out signals. And UP/
When this load signal is input, the DOWN counter 6 takes in the count value of the UP/DOWN counter 7 at that time and rewrites the count value. That is,
The count value of UP/DOWN counter 7 is
Transferred to UP/DOWN counter 6, counter 6
The count value is rewritten to the transferred count value. Note that the reset signal sent by the comparator 15 and the frequency divider 1
The load signal sent by 6 is branched to OR gate 1.
7, and or gate 1
The output of the flip-flop circuit 11 is input to the R terminal of the flip-flop circuit 11.

Next, the operation of the device configured in this way will be explained. That is, it is assumed that the automobile is currently traveling straight ahead and that the rotary disk 1, which rotates in conjunction with the steering wheel, is at the rotation center position as shown in FIG. At this time, the count value on the UP/DOWN counter 6 should actually be zero, but it may become less than zero due to the electrical noise mentioned above or the rotation of the handle after the ignition switch is turned off. There may be cases where the count value is shifted. If such a deviated count value is input to the decoder 8, a problem arises in that the variable operation of the illumination direction of the headlamp, which is controlled using the decoder 8, is deviated in accordance with the count value. However, in this embodiment, since the correction operation as described below is quickly performed, it becomes possible to control the illumination direction of the headlight in conjunction with the steering wheel steering without any trouble.

In other words, it is no exaggeration to say that most of the roads a car travels on are straight roads, and the steering wheel is turned once.
It will not be driven for long periods of time with it spinning.
In other words, even if the origin position detection signal is generated at the stone of the rotating disk and the position of one rotation in the left direction, the period of occurrence is short, and the origin position detection signal will be detected at the rotation center position after traveling for a short time. . In the inventor's research based on an actual vehicle, it was found that although the steering wheel may be rotated once while driving on a U-turn road, etc., the time required to return the steering wheel to the steering wheel center was less than 30 seconds. That is, after the origin position detection signal is generated at one rotation position in the right and left directions, the origin position detection signal is always generated at the rotation center position within 30 seconds.
Therefore, if no origin position detection signal is generated at any other origin position until 30 seconds have elapsed, the current origin position may be determined to be the rotation center position.

Now, flip-flop circuit 11 and frequency divider 1
6 is in the initial reset state and the origin position detection signal is generated at the rotation center position of the rotary disk, that is, at the straight-ahead steering position. At this time, an "H" level origin position detection signal is input to AND gate 10 and AND gate 12. A flip-flop circuit 11 is connected to the other end of the AND gate 10.
Since the output of , that is, the "H" level signal has already been input, the origin position detection signal input to one end passes through the AND gate 10 and is output to UP/
The DOWN counter 7 is reset and the flip-flop circuit 11 is set. As a result, the count value in the UP/DOWN counter 7 becomes zero, and the flip-flop circuit 11 sets its Q output and output levels to "H" and "L". When the output of flip-flop circuit 11 is inverted to "L" level, the gate of AND gate 10 is closed, but when its Q output is inverted to "H" level, the gates of AND gates 12 and 13 are opened. Therefore, the clock pulse signal sent from the reference clock generator 14 passes through the AND gate 13 and begins to be input to the frequency divider 16, and at the same time, the origin position detection signal passes through the AND gate 12. This and gate 12
The comparator 15 is activated by the origin position detection signal that passes through the UP/DWON counter 7, and takes in the current count value of the UP/DWON counter 7 to obtain the reference comparison count value.
Compare with N ₀ . At this time, the count value of the counter 7 has already become zero due to the origin position detection signal inputted through the AND gate 10.
It matches the reference comparison count value N ₀ =0. Therefore, comparator 15 does not send a reset signal to frequency divider 16, and frequency divider 16 continues to divide the frequency of the input clock pulse signal. This frequency dividing operation in the frequency divider 16 continues not only during the period when the origin position detection signal is generated at the rotation center position, but also during the period when the origin position detection signal is no longer generated. That is,
In general, even when an automobile is traveling straight ahead, it actually performs fine steering, and therefore an origin position detection signal may or may not be generated around the rotation center. Needless to say, when the origin position detection signal is generated, as a result of the comparison operation performed by the comparator 15 as described above, the reset signal is not sent to the frequency divider 16. When the origin position detection signal is no longer generated, the comparison operation itself in the comparator 15 is not performed, so no reset signal is sent to the frequency divider 16. In other words,
Once the origin position detection signal is generated at the rotation center position, the frequency dividing operation in the frequency divider 16 continues even if the origin position detection signal is no longer generated. And in this state
When 30 seconds have elapsed, an overflow of the input clock pulse signal occurs in the frequency divider 16, and a load signal is sent to the UP/DOWN counter 6. However, the UP/DOWN counter 6 is
Upon receiving this load signal, the UP/DOWN counter 7
The current count value of is taken in and the count value is rewritten. That is, if the rotating disk 1 is at the rotation center position at this point, the UP/
The count value in DOWN counter 7 is zero, and this count value is transferred to UP/DOWN.
The count value of the counter 6 becomes zero. Also, at this time, the rotating disk 1 is not at the rotation center position and rotates (±
(within one revolution), accurate counting is performed in the UP/DOWN counter 7 with the rotation center position as a zero reference, and this count value is transferred to the counter 6. In other words, even if the UP/DOWN counter 6 makes a miscount, the UP/DOWN counter 6 receives an accurate count value based on the rotation center position and performs appropriate correction. Note that the load signal sent from the frequency divider 16 is
The signal is also input to the R terminal of the flip-flop circuit 11 via the flip-flop circuit 7, and the flip-flop circuit 11 is reset to prepare for generation of the next origin position detection signal.

Incidentally, the above operation has been described with respect to the operation after the origin position detection signal is generated at the straight-ahead steering position, but while the automobile is running, the origin position detection signal is also generated at the one-turn steering position.
Now, the flip-flop circuit 11 and the frequency divider 16
It is assumed that the motor is in the initial reset state and the origin position detection signal is generated at one rotation steering position. At this time, the "H" level origin position detection signal is input to the AND gates 10 and 12 in the same manner as described above, the count value in the UP/DOWN counter 7 becomes zero, and the reference clock is generated in the frequency divider 16. The clock pulse signal sent by the device 14 begins to be input. At this time, the comparator 15 takes in the count value of the counter 7 and compares it with the reference comparison count value N ₀ , but since the count value of the counter 7 has already reached zero at this point, it matches the reference comparison value N ₀ =0. Therefore, the frequency divider 16 continues to perform the frequency division operation without being reset. However, as mentioned above, the time required to return the steering wheel from the steering position once to the steering wheel center is less than 30 seconds. Therefore, in ANDGATE 12
Within 30 seconds, the origin position detection signal generated at the rotation center position comes to be input, and the comparator 15 performs the comparison operation again at the time when this origin position detection signal is generated. At this time, comparator 1
The count value of counter 7 taken into 5 is 1
This is a count value for one rotation with the rotational steering position as a zero reference, and does not match the reference comparison count value N ₀ =0. Therefore, the comparator 15 sends out an "H" level signal at this point, and the frequency divider 16
Reset. Here, the timing of the reset signal input to the frequency divider 16 is within 30 seconds after the clock pulse signal begins to be input to the frequency divider 16. Therefore, the frequency divider 16 is reset without waiting for the overflow of its clock pulse signal, and no load signal is sent to the UP/DOWN counter 6. In other words, the count value on the counter 7 at this time is the count value when the position of one rotation in the right or left direction of the rotating disk is set as the temporary rotation center position, and using this count value,
The count value of the UP/DOWN counter 6 is not corrected. Then, the reset signal sent by the comparator 15 is sent to the OR gate 17.
The signal is also input to the R terminal of the flip-flop circuit 11 via the flip-flop circuit 11, and the flip-flop circuit 11 is reset to prepare for generation of the next origin position detection signal.

As explained above, according to the device according to this embodiment, the UP/DOWN counter 7 performs counting with each origin position set as a temporary rotation center position, but the count value transferred to the UP/DOWN counter 6 is a count value that corresponds to the true rotation center position, and accurate and appropriate correction is performed using this count value, making it possible to control the illumination direction of the headlight without any problems in conjunction with steering wheel steering. . Furthermore, once the origin position detection signal is generated at the rotation center position, even if the steering wheel is subsequently steered (within ±1 rotation),
The correction in the UP/DOWN counter 6 is performed appropriately, and even when the vehicle is traveling on a curve, the correction of the variable operation of the illumination direction of the headlight is reliably performed, thereby ensuring safety when traveling on a curve.

In this embodiment, the frequency division ratio of the frequency divider 16 is set to 30 seconds in terms of time, but it is not necessarily limited to 30 seconds, and the time is not limited to 30 seconds until the steering wheel reliably returns from one rotation steering position to the steering wheel center. It goes without saying that any value may be set as long as the time is longer than .

Furthermore, in this embodiment, the correction operation of the counter in a so-called cornering lamp system that changes the illumination direction of the headlight in conjunction with steering wheel steering has been explained. The counter in the system may be corrected. In addition, the present invention is not limited to such counter correction; it is also possible to determine the rotation center of a rotating body that rotates in conjunction with an external operation, and perform various controls based on the determined rotation center. Its utility value is extremely high.

〔Effect of the invention〕

As explained above, according to the method for determining the center position of a rotating body according to the present invention, a predetermined rotation angle position of the rotating body that rotates clockwise and counterclockwise in conjunction with steering wheel steering is set as the origin position, and one of the rotating bodies Among the origin positions that are located for each rotation, the origin position where no other origin position is detected until a predetermined time elapses after the origin position is detected is determined as the rotation center position of this rotating body. Among the origin positions that are located every other revolution, the origin position where no other origin position can be detected until a predetermined period of time has elapsed is determined as the rotation center position of the rotating body. When rotating in conjunction with steering, it is possible to accurately determine the straight steering system regardless of whether or not the vehicle is traveling straight, and the counter error in the rotation position detector can be detected at the time of determining the straight steering position. It becomes possible to correct the count. In other words, even when the vehicle is running on a curve, it is possible to reliably correct the variable operation of the headlight illumination direction based on the count value of the counter, thereby ensuring safety when running on a curve. .

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of the method for determining the center position of a rotating body according to the present invention, and FIG. 2 is a schematic configuration diagram showing a rotational position detection sensor used in this method for determining the center position. 1...Rotating disk, 1b...Slit for detecting origin position, 2-4...Photo interrupter, 6, 7...
...UP/DOWN counter, 11...RS flip-flop circuit, 14...Reference clock generator, 1
5... Comparator, 16... Frequency divider.

Claims (1)

[Claims] 1. A rotating body that rotates clockwise and counterclockwise in conjunction with steering wheel steering, and origin position detection that detects the origin position of this rotating body every rotation, with a predetermined rotation angle position of this rotating body as the origin position. Among the origin positions located every rotation of the rotating body, the origin position where no other origin position is detected until a predetermined time elapses after the detection of the origin position is detected in the clockwise and counterclockwise directions of the rotating body. A method for determining the center position of a rotating body, characterized in that the center position of a rotating body is determined as a rotation center position in a clockwise direction.