JPH0367888B2 - - Google Patents

Abstract

PURPOSE:To improve the extent of control accuracy, by making a position, staying within the specified turning angle range centering on the zero position for more than the specified time, 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, while a zero position detecting signal in inputted into each of AND gates 10 and 12. And, among zero positions situated at every rotation of the rotating disc 1, a zero position, staying within the specified turning angle range centering on the zero position for more than the specified time, is judged as a rotational center position, for example, each lighting direction of headlights is controlled.

Description

[Detailed Description of the Invention] [Field of Industrial Application] 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 disk that rotates in conjunction with steering wheel steering, and two photo interrupters are placed adjacent to each other at the positions where the slits pass. The system performs various controls linked to the steering wheel.

That is, in conjunction with steering wheel steering, the first and second photointerrupters generate pulsed electrical signals having the same waveform but with a phase difference of approximately 90°,
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 that remains within a predetermined rotation angle range that is greater than the wobbling width of the handle about the origin position for a predetermined time or longer after the origin position is detected is determined as the rotation center position of this rotating body. This is how it was done.

[Effect]

Therefore, according to the present invention, among the origin positions located every other revolution of the rotating body, the origin positions that remain within a predetermined rotational angle range around the origin position for a predetermined period of time after detection of the origin position are rotated. It can be determined as the center of rotation of the 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 electric signal 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 an AND gate 12, and the clock pulse signal sent from the reference clock generator 14 is input to the other end of the AND gate 12. There is. The clock pulse signal passing through the AND gate 12 is input to a frequency divider 13, and the frequency divider 13 overflows every time this clock pulse signal is input for 30 seconds or more, and performs an UP/DOWN signal. A load signal is sent to the counter 6. Then, when this load signal is input, the UP/DOWN counter 6 calculates the UP/DOWN value at that point.
The count value of the counter 7 is taken in and the count value is rewritten. That is, the count value of the UP/DOWN counter 7 is transferred to the UP/DOWN counter 6, and the count value of the counter 6 is rewritten to the transferred count value.

On the other hand, the count values of the UP/DOWN counter 7 are compared in a comparator 15, and the comparator 15 contains count values corresponding to rotation angle positions of ±180° with respect to the rotation center of the rotating disk. ±x is set as the comparison reference count value. That is, comparator 15
is adapted to send a reset signal to the frequency divider 13 if the count value input via the UP/DOWN counter 7 is not within the range of ±x counts. The reset signal sent by the comparator 15 and the load signal sent by the frequency divider 13 are branched and input to an OR gate 16, and the output of the OR gate 16 is input to the R terminal of the flip-flop circuit 11. It's becoming like that.

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 one rotation of the steering wheel, the period of occurrence is short;
After running for a short time, the steering wheel returns to the vicinity of the steering wheel center. In the inventor's research based on the actual vehicle,
On a U-turn road, etc., the vehicle may be driven by rotating the steering wheel once, but the time required to return the steering wheel to the vicinity of the steering wheel center was less than 30 seconds. In other words, after the origin position detection signal is generated at the one-turn steering position, the steering wheel is always steered by a rotation angle of 180 degrees or more within 30 seconds. Therefore, if the steering wheel is not turned by 180 degrees or more within 30 seconds after the origin position detection signal is generated, the origin position at that time can be determined to be the rotation center position.

Now, flip-flop circuit 11 and frequency divider 1
3 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 the AND gate 10. Since the output of the flip-flop circuit 11, that is, the "H" level signal has already been input to the other end of the AND gate 10, the origin position detection signal input to one end of the AND gate 10 is
0, the UP/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 the flip-flop circuit 11 is inverted to the "L" level, the gate of the AND gate 10 is closed, but when the Q output is inverted to the "H" level, the gate of the AND gate 12 is 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 13. At this time, the count value of the counter 7 has already become zero due to the origin position detection signal inputted via the AND gate 10, so the comparator 15 does not send out a reset signal and the frequency divider 13 The frequency division operation of the input clock pulse signal is continued. This frequency division operation is
This is performed not only when the count value of the counter 7 is zero, but also continuously within the range of ±X counts. That is, if the steering is within ±180 degrees about the center of the steering wheel, the comparator 15 does not send out a reset signal, and the frequency dividing operation in the frequency divider 13 continues. However,
When 30 seconds pass in this state, the frequency divider 13
At , an overflow of the input clock pulse signal occurs, and a load signal is sent to the UP/DOWN counter 6. Then, the UP/DOWN counter 6 receives this load signal and operates the UP/DOWN counter 6.
The current count value of the DOWN counter 7 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 count value of the UP/DOWN counter 7 is zero, and this count value is transferred, and the count value of the UP/DOWN counter 6 becomes zero. . At this time, if the rotating disk 1 is not at the rotation center position and is rotating (within ±180°), the UP/DOWN counter 7 performs accurate counting with the rotation center position as the zero reference. , this count value will be transferred to the counter 6. In other words, even if the UP/DOWN counter 6 has made a miscount, the UP/DOWN counter 6
An accurate count value based on the rotation center position is taken into the DOWN counter 6, and appropriate correction is performed. The load signal sent from the frequency divider 13 is input to the R terminal of the flip-flop circuit 11 via the OR gate 16, and the flip-flop circuit 11 is reset to prepare for generation of the next home 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, flip-flop circuit 11 and frequency divider 13
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 gate 10 in the same manner as described above, the count value in the UP/DOWN counter 7 becomes zero, and the reference clock generator 14 is input to the frequency divider 13. The clock pulse signal sent by the clock pulse signal begins to be input. At this time, the count value in the UP/DOWN counter 7 is zero, so it is within the range of the comparison reference count value ±X, and therefore the comparator 15 does not send a reset signal to the frequency divider 13.
The frequency dividing operation in the frequency divider 13 continues. However, as described above, the time required to return the steering wheel from the one-turn steering position to the vicinity of the steering wheel center is less than 30 seconds. Therefore, UP/
The count value on the DOWN counter 7 counts 180 degrees or more in terms of the rotation angle of the handle within 30 seconds, and falls outside the range of the comparison reference count value ±X. At this point, the comparator 15 sends out an "H" level signal to reset the frequency divider 13. Here, the timing of the reset signal input to the frequency divider 13 is within 30 seconds after the clock pulse signal begins to be input to the frequency divider 13. Therefore, the frequency divider 13 is reset without waiting for the overflow of its clock pulse signal, and the UP/
No load signal is sent to the 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 this count value is used to calculate the UP/DOWN counter 6. No correction is made to the count value in . The reset signal sent from the comparator 15 is also input to the R terminal of the flip-flop circuit 11 via the OR gate 16, and the flip-flop circuit 11 is put into a reset state in preparation for generation of the next home 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. . In addition, once the origin position detection signal is generated at the rotation center position, even if the steering wheel is turned (within ±180°), the UP/
The correction in the 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, and safety during curve travel is ensured.

In this embodiment, the comparison reference count value ±X in the comparator 15 is set to a value corresponding to ±180° of the rotation angle of the steering wheel. For example, it does not necessarily have to correspond to ±180°. Further, although the frequency division ratio of the frequency divider 13 is set to 30 seconds in terms of time, it is not limited to 30 seconds. That is, it can be set to a value intended by the designer, taking into account the time it takes for the steering wheel to return from the one-turn steering position and the amount of rotation angle thereof.

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.

[Effects of the Invention] As explained above, according to the method for determining the center position of a rotating body according to the present invention, the 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, Of the origin positions that are located every rotation of this rotating body, the origin position that remains within a predetermined rotation angle range that is greater than the wobbling width of the handle with the origin position as the center for a predetermined period of time after detection of the origin position is determined by this rotating body. Since the rotation center position is determined as the rotation center position of the rotating body, among the origin positions that are located every other rotation of the rotating body, the origin position that remains within a predetermined rotation angle range around the origin position for a predetermined period of time after the origin position is detected. is determined as the rotation center position of the rotating body, and for example, when this rotating body is rotated in conjunction with the steering wheel of an automobile, etc., the straight-line steering position can be accurately determined regardless of whether the vehicle is traveling straight or not. This makes it possible to correct the miscount of the counter in the rotational position detector at the time of determining the straight steering position. 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, 13 ... frequency divider, 14 ... reference clock generator, 15 ... comparator.

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. and an origin that remains within a predetermined rotational angle range that is greater than or equal to the wobbling width of the handle around the origin position for a predetermined period of time or more after the origin position is detected, among the origin positions that are located for each rotation of the rotating body. A method for determining a center position of a rotating body, characterized in that the position is determined as a rotation center position of the rotating body in a clockwise direction and a counterclockwise direction.