JPH0614067B2 - Rotation detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotation detecting device used for a vehicle speed sensor of an automobile, for example.

(Prior Art) Recently, the speed of introduction of electronics technology in the field of automobile technology is remarkable, and not only in the fields of engine systems such as electronic fuel injection control systems for engines and vehicle constant-speed travel control systems and normal travel systems, but also for steering control and It has come to be applied to the field of secondary traveling systems such as suspension control.

In any of these control systems, the speed of the vehicle has a very important position as a control input element, and the accuracy and reliability of the detection device also determine the superiority or inferiority of the performance of the control system itself.

As a means for detecting such a vehicle speed, a through hole is formed in the circumferential direction of a rotating disk in a generally used one, and a light emitting body such as an LED and a light receiving body such as a phototransistor are formed through the through hole. In such a way that the pulse signal output corresponding to the rotation speed is obtained in a light-receiving / light-shielding cycle that changes depending on the rotation of the rotating disk.

However, in that case, if the through holes are formed in a single row and the light emitter and the light receiver are in a single set, if the rotation sensor of the single set fails, it cannot be detected at all. When the column itself is a single column, an error is likely to occur in the detection signal. Therefore, the through holes are formed in two columns on the concentric circles by mutually changing the phases, and the rotation sensor is also associated with them. There is a structure in which the detection accuracy is improved by providing a pair of rotation sensors and the remaining rotation sensors maintain a minimum detection function even if one rotation sensor fails (for example, see Japanese Utility Model Laid-Open No. 55-172856). .

However, in such a configuration, even if one set of rotation sensors fails, only the rotation speed (or rotation speed) can be detected, and the rotation direction cannot be detected at all. Moreover, there is a drawback that it is not always easy to form two rows of through holes with high accuracy by concentrically changing the phases on the same rotating disk.

(Object of the Invention) The present invention has been made in order to improve the above-mentioned drawbacks, and at least three sets of rotation detecting means are provided to be offset from each other in the same phase with respect to the rotating disk, and at least three sets are provided. A combination of at least two detection outputs, which are different from each other, is formed into a logical value signal for forward rotation determination and a reverse rotation determination indicating a phase shift direction. By detecting the rotation speed and the rotation direction from the combination of two kinds of logical value signals, even if one phase fails, the detection accuracy is not lowered, and further, both the rotation speed and the rotation direction are detected. An object of the present invention is to provide a rotation detection device capable of detection.

(Means for Achieving the Object) In order to achieve the above object, the present invention provides a rotating disc connected to a rotating shaft and a constant pitch in the circumferential direction over the entire circumference of the rotating disc. A plurality of detected parts and a plurality of detected parts provided on the rotation locus of the plurality of detected parts at regular intervals in the circumferential direction, and a predetermined cycle corresponding to each of the plurality of detected parts. And at least three rotation detecting means for generating three sets of binary signals which are continuous with each other and have the same phase difference from each other, and the first to third rotation detecting means. Two different binary detection signals from among the first to third three binary detection signals are input, and a forward rotation direction determination and a reverse rotation direction are performed based on a combination of the binary detection signals of each of the two sets. Phase determining means for forming three sets of logical value signals for determination and relatively determining the phase shift direction; The first set of the normal direction of the rotating disk is input from the logical sum of the three sets of logical value signals for the normal direction determination of the phase determining means.
Rotation direction determining means and second rotation direction determining means for determining the reverse rotation direction of the rotating disk from the logical sum of the three logical value signals for determining the reverse rotation direction of the phase determining means. Be prepared.

(Operation) According to the above means, first, the binary output signals are located on the rotation loci of the plurality of detected parts of the rotating disk provided with the plurality of detected parts at a constant pitch over the entire circumference. Are provided at predetermined intervals so that they are output with the same phase shifted by the same phase, at least three sets of rotation detecting means are provided. Then, by the phase determination means, at least two sets of rotation detection means which are mutually different from each other are used.
The logical value of the value output is taken, and the direction of phase shift is discriminated by the three sets of logical value signals each formed in the normal direction and the reverse direction. After that, the normal direction 3 of the phase discrimination means
1st, 2nd to which each logic value signal of the group
The rotation speed and the rotation direction are detected from the comparison of the respective logical sum signals. Therefore, even if one of the rotation detecting means fails, the rotation speed and the rotation direction can be detected regardless of the detection accuracy.

Further, the rotation speed can be detected by the last one set of rotation detecting means even if the two sets of rotation detecting means fail.

(Embodiment) FIGS. 1 to 4 show a rotation detection device according to an embodiment of the present invention.

First, FIG. 1 is a perspective view showing a configuration of a sensor portion of the rotation detecting device, and reference numeral 1 is a predetermined (constant) in the circumferential direction.
It is a rotating disk in which a plurality of through holes (corresponding to a detected portion in the claims) 2, 2 ... Are formed at intervals. This rotary disc 1 is connected to a rotary shaft 3 such as a wheel drive shaft,
The rotary shaft 3 rotates according to the rotation of the rotary shaft 3.

On the other hand, reference numerals S _{1 to} S ₃ correspond to the through holes 2, 2 ... Part of the rotating disc 1, and the first to third three sets installed on the rotation loci thereof. Rotation sensors (corresponding to the rotation detecting means in the claims), which are located at intervals of 120 ° from each other, and each have, for example, a light emitting diode (LED) as a light emitting portion on the upper side and a light emitting diode (LED) on the lower side. It is composed of a U-shaped body provided with a phototransistor as a light receiving portion, and each output signal thereof is also shifted and output in the same phase with respect to the rotation direction of the rotating disk 1.

Each of the first to third rotation sensors S _{1 to} S ₃ generates and outputs a rotation detection pulse, which is a high / low binarized signal, at a cycle corresponding to the rotation speed of the rotating disk 1. ,
As shown in FIG. 2, each of these pulse outputs is first
First to sixth after being amplified by the third amplifiers A _{1 to} A ₃
Of the D-type (delay type) flip-flop circuits F _{1 to} F ₆ are supplied as data or clock inputs.

The respective data and clock input terminals of the _first to _sixth flip-flop circuits F _{1 to} F ₆ are connected as shown in the drawing, and the output (FIG. 3a) of the first amplifier A ₁ is the first. , The data input to the second flip-flop circuits F ₁ and F ₂ , and the clock input to the fifth and sixth flip-flop circuits F ₅ and F ₆ . The output of the second amplifier A ₂ (FIG. 3b) is the output of the third and fourth flip-flop circuits F ₃ ,
It becomes the data input of F ₄ and the clock input of the first and second flip-flop circuits F ₁ and F ₂ . Furthermore, the output of the third amplifier A ₃ (FIG. 3c) is the data input of the fifth and sixth flip-flop circuits F ₅ and F ₆ , and the third and fourth flip-flop circuits F ₃ and F _4. It becomes the clock input of.

Therefore, the first and second flip-flop circuits F ₁ and F ₂
Captures the output of the first amplifier A ₁ at the timing of the output of the second amplifier A ₂ (FIG. 3b) (however, the clock edges of F ₁ and F ₂ are different) and inputs the next clock. The time corresponding to the output of the first amplifier A ₁ is maintained until Q is supplied. Further, the other third flip-flop circuit F ₃ and fourth flip-flop circuit F ₄ , and the fifth flip-flop circuit F ₅ and sixth flip-flop circuit F ₆ also operate in the same relationship.

On the other hand, the first to sixth flip-flop circuits F _{1 to} F
Each Q output terminal of _6, the first to sixth respectively corresponding 2
While being connected to one of the input terminals of the input AND circuits Y _{1 to} Y ₆ , the first flip-flop circuit F ₁ and the second flip-flop circuit F ₂ and the third flip-flop circuit F ₃ and the fourth flip-flop circuit F ₃ are connected. Flip-flop circuit F ₄ , fifth flip-flop circuit F ₅ and sixth flip-flop circuit F
₆ , first and second AND circuits Y ₁ and Y ₂ , whose output terminals correspond to each other, and third and fourth AND circuits Y
It is connected to the cascade of the input terminals on the other side of each of the ₃ · Y ₄ , the fifth and the sixth AND circuits Y ₅ · Y ₆ .

Therefore, the first AND circuit Y ₁ respectively inputs the Q output of the _first flip-flop circuit F ₁ and the output of the second flip-flop circuit F ₂ and outputs the logical product output (third output)
2d), the second AND circuit Y ₂ inputs the Q output of the _second flip-flop circuit F ₂ and the output of the first flip-flop circuit F ₁ respectively, and outputs the logical product output (FIG. 3).
e), the third AND circuit Y ₃ outputs the Q output of the _third flip-flop circuit F ₃ and the fourth flip-flop circuit F 3.
_{4 and} the output of ₄ respectively and the logical product output (Fig. 3
d), the fourth AND circuit Y ₄ outputs the Q output of the _fourth flip-flop circuit F ₄ and the third flip-flop circuit F 4.
₃ output and the logical product output (Fig. 3
e), the fifth AND circuit Y ₅ outputs the Q output of the _fifth flip-flop circuit F ₅ and the sixth flip-flop circuit F 5.
₆ output and the logical product output (Fig. 3
d), the sixth AND circuit Y ₆ outputs the Q output of the _sixth flip-flop circuit F ₆ and the fifth flip-flop circuit F 6.
_And the output of FIG.
e) are output respectively. The first to sixth flip-flop circuits F _{1 to} F ₆ and the first to sixth AND circuits Y
_{1 to} Y ₆ form the phase determining means in the claims.

Then, the first, third, and fifth AND circuits Y ₁ ,
The outputs of Y ₃ and Y ₅ (Fig. 3d) are 3 for the normal direction determination.
The inputs of the first OR circuit O ₁ and the outputs of the second, fourth, and sixth AND circuits Y ₂ , Y ₄ , and Y ₆ are also three-input second OR circuit O ₂ for determining the reverse direction. Are respectively input to and the respective logical sums are taken. These first and second OR
Outputs of respective logical sums of the circuits O ₁ and O ₂ (corresponding to first and second rotation direction determining means in claims) (f, g in FIG. 3)
Are the first, second and third rotation sensors S ₁ , S ₂ , S ₃
The rotation direction detection signal is a combination of the three-phase outputs.

As a result, when the output of the first OR circuit O ₁ becomes H (high level) from the time charts of FIGS. 3 (a) to 3 (g), the rotary disk 1 is the first rotation sensor. When the rotation direction from S ₁ to the third rotation sensor S ₃ (S ₁ → S ₃ ) is in the normal rotation direction, while the output of the second OR circuit O ₂ is H (high level), It is shown that the rotating disc 1 is in the rotation direction (S ₃ → S ₁ ) from the _third rotation sensor S ₃ to the first rotation sensor S ₁ , that is, in the reverse direction. On the other hand, when the output of the first OR circuit O ₁ is L (low level), it is indicated that the forward / reverse direction is unknown or the reverse direction, and at least not the forward direction.
Further, when the output of the second OR circuit O ₂ is L, it is indicated that the forward / reverse direction is unknown or the normal rotation direction, and at least it is not the reverse rotation direction. Therefore, for example, in the above state, one of the rotation sensors, for example, the third sensor
Assuming that the rotation sensor S ₃ of Fig. 4 fails, Figs. 4 (a) to (k)
As shown in the time chart of FIG.
The output of ₃ itself does not generate the correct rotation pulse,
The input states of the _fifth and _sixth flip-flop circuits F ₅ and F _{6 which} receive the output of the third rotation sensor S ₃ as data input change as shown in FIG. 4c. On the other hand, its clock input does not change. Therefore, the fifth flip-flop circuit F ₅ reads the input of FIG. 4c at the clock input of FIG. 3a (FIG. 4a) and outputs the Q output corresponding to the data input during the clock cycle. It produces an inverted output. On the other hand, the data input to the sixth flip-flop circuit F ₆ also changes.

Furthermore, the above results, the third rotation sensor S 3 to the clock input the output of the _third and fourth flip-flop circuit F _3, F ₄ Q, also changes output. Therefore, as a result of the above, the output of the _third AND circuit ₃ changes as shown in FIG. 4f, and the output of the _fifth AND circuit Y ₅ changes as shown in FIG. 4h. However, in this case, the outputs (e, g, i in FIG. 4) of the second, fourth, and sixth AND circuits Y ₂ , Y ₄ , Y ₆ for determining the reverse rotation direction do not change. Therefore, the output of the second OR circuit O ₂ remains L.

On the other hand, the output of the _first AND circuit Y ₁ is because the first and second rotation sensors S ₁ and S ₂ are normal.
The H output (Figs. 3d and 4d) is maintained as in normal operation. Therefore, the output of the first OR circuit O ₁ is eventually H, and it is determined that the normal direction is the normal direction.

(Effects of the Invention) As described above, the present invention provides a rotating disk connected to a rotating shaft and a plurality of detected objects provided at a constant pitch in the circumferential direction over the entire circumference of the rotating disk. And a plurality of parts to be detected, which are provided at regular intervals in the circumferential direction on the rotation loci of the parts to be detected, are continuous in a predetermined cycle in correspondence with each of the plurality of parts to be detected, and The first to third at least three rotation detecting means for generating three sets of binary signals having the same phase difference to each other, and the first to third rotation detecting means by the first to third rotation detecting means. Of the two sets of binary detection signals, mutually different two sets of binary detection signals are input, and from the combinations of the two sets of binary detection signals, three sets for forward rotation direction determination and three sets for reverse rotation direction determination are input. Phase discriminating means for forming a logical value signal to discriminate the relative phase shift direction; and the positive discriminating means of the phase discriminating means. Three sets of logical value signals for determining the direction of rotation are input, and first rotation direction determining means for determining the forward direction of the rotating disk based on the logical sum of those signals, and 3 for determining the reverse direction of the phase determining means.
It is provided with a second rotation direction judging means for inputting a set of logical value signals and judging the reverse direction of the rotating disk from the logical sum of them.

That is, according to the present invention, first, the respective binary output signals are located on the rotation loci of the plurality of detected parts of the rotating disk provided with the plurality of detected parts at a constant pitch over the entire circumference. There are provided at least three sets of rotation detecting means, which are first to third, at predetermined intervals so as to be output with the same phase shifted. Then, the phase discriminating means takes the logical value of the binary output of the rotation detecting means for at least every two sets different from each other, and by the logical value signals of the respective three sets of the normal direction and the reverse direction formed as a result. Determine the phase shift direction. After that, the first and second logical value signals of the three sets of normal rotation directions and the three reverse rotation directions of the phase determination means correspond to
The rotation speed and the rotation direction are detected from the comparison of the respective OR signals input to the second rotation direction determination means. Therefore, even if one of the rotation detecting means fails, the rotation speed and the rotation direction can be detected regardless of the detection accuracy.

Further, the rotation speed can be detected by the last one set of rotation detecting means even if the two sets of rotation detecting means fail.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a rotation sensor unit of a rotation detecting device according to an embodiment of the present invention, FIG. 2 is an electric circuit diagram of the rotation detecting device, FIG. 3 and FIG. It is a time chart which shows circuit operation. 1 ...... rotating disk 3 ...... rotary shaft S ₁ to S ₃ ...... first to third rotation sensors F ₁ to F ₆ ...... first to sixth flip-flop circuit of the Y ₁ to Y ₆ ...... first 1st to 6th AND circuits O ₁ , O ₂ ... First and second OR circuits

Claims (1)

[Claims] 1. A rotary disk connected to a rotary shaft, a plurality of detected parts provided at a constant pitch in a circumferential direction over the entire circumference of the rotary disk, and rotation of the plurality of detected parts. Three sets of three sets are provided on the trajectory at regular intervals in the circumferential direction, are continuous in a predetermined cycle corresponding to each of the plurality of detected parts, and have the same phase difference from each other. At least three first to third rotation detecting means for generating a binary signal and one of the first to third three sets of binary detection signals by the first to third rotation detecting means are mutually mutually Binary detection signals of two different sets are input, and from each combination of the two sets of binary detection signals, three sets of logical value signals for forward rotation direction determination and reverse rotation direction determination are formed, and relative phase is formed. Of the phase discriminating means for discriminating the deviation direction of the input signal and three sets of logical value signals for discriminating the normal direction of the phase discriminating means , The first rotation direction determining means for determining the forward rotation direction of the rotating disk from the logical sum of these, and the three sets of logical value signals for determining the reverse direction of the phase determining means are input, and from the logical sum of them A rotation detection device comprising a second rotation direction determination means for determining the reverse rotation direction of the rotating disk.