JPH0754246B2 - Center position determination method for rotating body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is suitable for determining the center position of a rotating body that is used to determine the rotational center position of a rotating body that rotates in association with steering of a vehicle or the like. It is about the method.

[Conventional technology]

2. Description of the Related Art Conventionally, in vehicles such as automobiles, a plurality of slits are provided at equal angular intervals in a rotating disk that rotates in association with steering of a steering wheel, and two photo interrupters are arranged adjacent to each other at the position where the slits pass. , Performs various controls linked to steering.

That is, in association with steering of the steering wheel, the first and second
The photo interrupter generates a pulse-shaped electric signal having the same waveform and a phase difference of approximately 90 °, and the electric signal is counted to detect the rotation direction and the rotation position of the handle.

[Problems to be Solved by the Invention]

However, according to such a conventional rotational position detector, in the case where the counter causes a miscount due to electric noise or the like, there is no means for correcting the error, and therefore the system is accumulated due to the error accumulation. There was a problem that malfunction occurred.

Also, in order to reduce power consumption, if the power supply to the rotational position detector is cut off after the ignition switch is turned off, the rotational position change of the steering wheel until the next ignition switch is turned on will cause an error. ,
It was something that was accumulated.

[Means for Solving the Problems]

The present invention has been made to solve such a problem, and sets a predetermined rotation angle position of a rotating body that rotates in a clockwise direction and a counterclockwise direction in conjunction with steering of a steering wheel as an origin position,
Among the origin positions that are located for each rotation of the rotor, the origin position that does not detect other origin positions after the origin position is detected and before traveling a predetermined distance is determined as the rotation center position of the rotor. It is a thing.

[Action]

Therefore, according to the present invention, among the origin positions that are positioned every other rotation of the rotating body, the origin position that cannot detect another origin position after the origin position is detected and before traveling for a predetermined distance is set to the origin position of the rotating body. It can be defined as the rotation center position.

〔Example〕

Hereinafter, the method for determining the center position of the rotating body according to the present invention will be described in detail. FIG. 1 is a block diagram showing an embodiment of the center position determining method. In the figure, 5 is an UP / DOWN switching circuit that receives a pulse-shaped electric signal sent from a rotational position detection sensor (Fig. 2) and sends processing signals (up signal and down signal) according to steering of the steering wheel, 6 Reference numerals 7 and 7 denote first and second UP / DOWN counters to which the processing signal sent by the UP / DOWN switching circuit 5 is input, and 8 an output terminal (not shown) at a position corresponding to the count value counted by the counter 6. ) Is selected and its level is set to "L" or "H", and 9 is a lamp drive circuit that changes the irradiation direction of the headlight (not shown) according to the output state of the decoder 8.

The rotational position detection sensor shown in FIG. 2 is composed of a rotating disc 1 that rotates in association with steering of a vehicle steering wheel, and photo interrupters 2 to 4 having a light emitting element and a light receiving element. Photo interrupters 2 and 3 are
It is arranged adjacent to the passage position of the slits 1a of the same shape opened at equal angular intervals on the outer peripheral surface of the rotary disc 1.
The photointerrupters 2 and 3 are adapted to generate a pulse-shaped electric signal having the same waveform and a phase difference of approximately 90 ° by passing through the slit 1a as the rotary disc 1 rotates. The electrical signal is input to the UP / DOWN switching circuit 5. Also, the rotating disk 1
A slit 1b for detecting the origin position is independently provided at a predetermined rotation angle position on the outer peripheral surface of the slit.
The passage of 1b is detected by the photo interrupter 4. That is, the slit 1b is the photo interrupter 4
Is set as the origin position of the rotary disc 1, and this origin position is set in correspondence with the steering position of the steering wheel (hereinafter, this steering position is referred to as the steering wheel center) during straight traveling. That is, in the handle center, the rotary disc 1 is located at the origin position as shown in the figure (hereinafter, this position is referred to as the rotary center of the rotary disc), and the handle centered on the handle center The origin position of the rotary disc 1 is detected to be deviated by 360 ° for each rotation in the clockwise direction and the counterclockwise direction. Generally, a steering wheel of an automobile can rotate less than two rotations in a clockwise direction (hereinafter, rightward direction) and a counterclockwise direction (hereinafter, leftward direction) about a steering wheel center. The photo interrupter 4 detects the total of three origin positions including the rotation center, and at the time of detecting the origin position, one of the input ends of the AND gate 10 in FIG. A signal is input.

On the other hand, the UP / DOWN switching circuit 5 processes the inputted 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 counters 6 and 7 are adapted to count up or count down the count value by the number of input up signals or down signals. That is, the count value of the UP / DOWN counter 6 is set to zero with reference to the time when the rotating disk is at the rotation center, and the count value is sequentially increased by steering the steering wheel to the right, and the count value is incremented by steering to the left. Are going down sequentially. And this
The count value sent by the UP / DOWN counter 6 is the decoder 8
The lamp driving 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 of the steering wheel. Also UP
In the same manner, the / DOWN counter 7 is configured such that the count value is sequentially increased by steering the steering wheel to the right, and the count value is sequentially reduced by steering the steering wheel to the left. When the level is reached, the count value of the counter 7 is reset and returns to zero.

On the other hand, the Q-bar 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 set to the S input of the flip-flop circuit 11. Is entered as. The Q output of the flip-flop circuit 11 is input to one end of the AND gates 12 and 13, and a pulse signal (distance signal) corresponding to the traveling distance is input to the other end of the AND gate 13. It is like this.
The origin position detection signal input to the AND gate 10 is branched and input to the other end of the AND gate 12, and the output of the AND gate 12 is input to the enable terminal of the comparator 15. It is like this. Then, when the "H" level signal is input to the enable terminal, the comparator 15 takes in the count value of the UP / DOWN counter 7 at the present time and outputs the reference comparison count value.
It is designed to compare with N ₀ = 0, and if the fetched count value does not match the reference comparison count value N ₀ = 0,
A reset signal is sent to the frequency divider 16.
A distance signal passing through the AND gate 13 is input to the frequency divider 16, and overflow / up / down occurs each time this distance signal is input as a travel distance of 200 m or more.
A load signal is sent to the counter 6.
Then, when the load signal is input, the UP / 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 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. The reset signal sent by the comparator 15 and the load signal sent by the frequency divider 16 are branched and input to the OR gate 17, and the output of the OR gate 17 is input to the R terminal of the flip-flop circuit 11. It has become so.

Next, the operation of the apparatus thus configured will be described. That is, it is assumed that the vehicle is traveling straight ahead and the rotating disc 1 that rotates in association with steering of the steering wheel is at the rotation center position as shown in FIG. At this time, UP / DOWN
The count value of the counter 6 should actually be zero, but it is a count value deviated from zero due to the above-mentioned electric noise or the handle rotation after the ignition switch is turned off. There are cases. When such a deviated count value is input to the decoder 8, there occurs a problem that the irradiation direction variable operation of the headlight controlled by the decoder 8 deviates corresponding to the count value. However, in the present embodiment, since the correction operation as described below is performed promptly, it becomes possible to control the irradiation direction of the headlight in conjunction with steering of the steering wheel without any trouble.

That is, it is no exaggeration to say that most of the roads of automobiles are straight roads, and the vehicle will not travel a long distance with the steering wheel rotated once. That is, even if the origin position detection signal is generated at the one-turn steering position of the steering wheel, its generation period is short, and the steering wheel returns to the vicinity of the steering wheel center after traveling a short distance. In a study based on the inventor's actual vehicle, the vehicle sometimes travels on the U-turn road with one rotation, but the traveling distance before returning the steering wheel to the vicinity of the steering wheel center is less than 200 m. In other words, after the origin position detection signal is generated at the 1-turn steering position, the rotation angle must be 18
Steering is performed at 0 ° or more. Therefore, after the origin position detection signal is generated, 18
If the steering wheel is not steered by 0 ° or more, the origin position at that time may be determined as the rotation center position.

It is now assumed that the flip-flop circuit 11 and the frequency divider 16 are in the initial set state, and the origin position detection signal is generated at the rotation center position of the rotating disk, that is, the straight steering position. At this time, the origin position detection signal of "H" level is input to the AND gates 10 and 12. Since the Q-bar 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 passes through the AND gate 10. , 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 outputs its Q output and Q
The bar output levels are “H” and “L”. The gate of the AND gate 10 is closed by inverting the Q-bar output of the flip-flop circuit 11 to the “L” level, but the gates of the AND gates 12 and 13 are opened by the Q output thereof being turned to the “H” level. . Therefore, the distance signal passes through the AND gate 13 and starts to be input to the frequency divider 16, and the origin position detection signal passes through the AND gate 12. The origin position detection signal passing through the AND gate 12 activates the comparator 15 to fetch the current count value of the UP / DOWN counter 7 and compare it with the reference comparison count value N ₀ . At this time, the count value of the counter 7 has already become zero due to the origin position detection signal input via the AND gate 10, and therefore coincides with the reference comparison count value N ₀ = 0. Therefore, the comparator 15 does not send the reset signal to the frequency divider 16, and the frequency divider 16 continues the frequency division operation of the input distance signal. This divider 16
The frequency dividing operation is continuously performed 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 not generated. That is, in general, an automobile actually performs fine steering even if it is traveling straight, and therefore an origin position detection signal is generated or not generated around the rotation center. Needless to say, when the origin position detection signal is generated, as described above, as a result of the comparison operation being performed in the comparator 15, the reset signal is not sent to the frequency divider 16. When the origin position detection signal is not generated, the reset operation is not sent to the frequency divider 16 because the comparison operation itself in the comparator 15 is not performed. That is, once the origin position detection signal is generated at the rotation center position, the frequency dividing operation of the frequency divider 16 is continuously performed even if the origin position detection signal is not generated. When the vehicle travels 200 m or more in such a state, the frequency divider 16 overflows the input distance signal, and the load signal is sent to the UP / DOWN counter 6. Upon receiving the load signal, the UP / DOWN counter 6 takes in the current count value of the UP / DOWN counter 7 and rewrites the count value. That is, at this time, the rotating disc 1
Is in the rotation center position, the count value in the UP / DOWN counter 7 is zero, and this count value is transferred, and the count value in the UP / DOWN counter 6 becomes zero. At this time, if the rotary disc 1 is not in the rotation center position and is rotating (within ± 1 rotation), the UP / DOWN counter 7 performs accurate counting with the rotation center position as the zero reference. Therefore, 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
An accurate count value based on the rotation center position is fetched in and corrective correction is performed. The load signal sent from the frequency divider 16 is input to the R terminal of the flip-flop circuit 11 via the OR gate 17, and the flip-flop circuit 11 is reset to prepare for the next origin position detection signal.

By the way, in the above operation, the operation after the origin position detection signal is generated at the straight-ahead steering position has been described, but the origin position detection signal is generated even at the one-turn steering position while the vehicle is traveling. Now, it is assumed that the flip-flop circuit 11 and the frequency divider 16 are in the initial set state and the origin position detection signal is generated at the one-turn steering position. At this time, the origin position detection signal of "H" level is input to the AND gates 10 and 12 in the same manner as described above, and the UP / D
When the count value of the OWN counter 7 becomes zero,
The distance signal starts to be input to the frequency divider 16. At this time, the comparator 15 fetches the count value of the counter 7 and compares it with the reference comparison count value N _0. However, since the count value of the counter 7 is already zero at this point, the reference comparison value N ₀ =
Since it matches 0, the frequency divider 16 continuously performs the frequency division operation without being reset. However, as described above, the travel distance from returning the steering wheel from the one-turn steering position to near the steering wheel center is less than 200 m. Therefore and gate
The origin position detection signal generated at the rotation center position will be input to 12 until it travels 200 m.
The comparator 15 performs the comparison operation again when the origin position detection signal is generated. At this time, the count value of the counter 7 fetched by the comparator 15 is a count value for one rotation with the one-turn steering position as the zero reference, and does not match the reference comparison count value N ₀ = 0. Therefore, the comparator
At this point, 15 sends out an “H” level signal, and the frequency divider
16 is reset. Here, the timing of the reset signal input to the frequency divider 16 is from when the distance signal starts to be input to the frequency divider 16 until when the vehicle travels 200 m. Therefore, the frequency divider 16 is reset without waiting for the overflow of the distance signal, and the load signal is not sent to the UP / DOWN counter 6. That is, the count value in the counter 7 at this time is the count value when the one rotation position in the right or left direction of the rotating disk is determined as the temporary rotation center position, and the UP / DOWN counter 6 is used by using this count value. There is no correction of 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 17, and the flip-flop circuit 11 is reset to prepare for the next origin position detection signal.

As described above, according to the device of this embodiment, the UP / D
The OWN counter 7 counts each origin position as a provisional rotation center position, but the count value transferred to the UP / DOWN counter 6 is the count value corresponding to the true rotation center position. Accurate and appropriate correction using the value is performed, and the irradiation direction of the headlight can be controlled without any trouble in conjunction with steering of the steering wheel. In addition, once the origin position detection signal is generated at the rotation center position, the UP / DOWN counter 6 is properly corrected even if the steering wheel is being steered thereafter (within ± 1 rotation), and the curve is traveling. Even if there is, the correction of the irradiation direction variable operation of the headlight is reliably performed.

In the present embodiment, the frequency division ratio of the frequency divider 16 is set to 200 m as the travel distance, but the distance is not necessarily limited to 200 m, and it is possible to reliably return the steering wheel from the one-turn steering position to the steering wheel center. It goes without saying that any value may be set as long as it is equal to or longer than the time.

Further, in the present embodiment, the correction operation of the counter in the so-called cornering lamp system in which the irradiation direction of the headlight is changed in association with the steering of the steering wheel has been described, but the movement is controlled in conjunction with the steering of the steering wheel. The counter in the system may be corrected.
Further, the correction is not limited to such a counter,
It is possible to determine a rotation center of a rotating body that rotates in association with an external operation, and various controls can be performed with the determined rotation center as a reference, and its utility value is extremely high.

〔The invention's effect〕

As described 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 in the clockwise direction and the counterclockwise direction in association with the steering of the steering wheel is set as the origin position, and 1 of this rotating body is used. Among the origin positions that are located for each rotation, the origin position that does not detect other origin positions after the origin position is detected and before traveling for a predetermined distance is determined as the rotation center position of this rotor. Of the origin positions located every other rotation, the origin position that cannot detect other origin positions after the origin position is detected and before traveling a predetermined distance can be set as the rotation center position of the rotating body. When this rotating body is rotated in association with steering of the steering wheel of an automobile or the like, it becomes possible to accurately determine the straight-ahead steering position, and at the time of determining the straight-ahead steering position, the rotational position detector It is possible to correct the definitive counter miscount of become.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a method for determining a center position of a rotating body according to the present invention, and FIG. 2 is a schematic diagram showing a rotational position detection sensor used in this center position determining method. 1 ... Rotating disk, 1b ... Origin position detection slit, 2
4 …… Photo interrupter, 6,7 …… UP / DOWN counter,
11 ... RS flip-flop circuit, 15 ... comparator,
16 ... Divider.

Claims (1)

[Claims] 1. A rotating body which rotates in a clockwise direction and a counterclockwise direction in association with steering of a steering wheel, and a predetermined rotation angle position of this rotating body as an origin position, and the origin position where this rotating body is positioned for each rotation is detected. And an origin position detecting means for detecting the origin position of the rotator, which does not detect another origin position of the rotator for each rotation of the rotator until it travels a predetermined distance after the origin position is detected. A method for determining a center position of a rotating body, characterized in that it is determined as a rotational center position in a clockwise direction and a counterclockwise direction.