JP4891849B2 - Rotation state detection device - Google Patents

Description

  The present invention relates to a rotation state detection device that detects a rotation state based on detection signals of two sensors having different phases converted into a binary signal.

  In order to detect the rotating state of the rotating body, two sensors are arranged at a predetermined interval along the rotating direction of the rotating body, and rotation is performed using each detection signal having a phase difference transmitted by these sensors. A method for detecting the number of rotations and the direction of rotation of a body is known. An example is disclosed in Japanese Patent Application Laid-Open No. 10-332725. A conventional example for detecting the rotational state of the rotating body will be described with reference to FIG.

  Reference numeral 1 denotes a gear whose rotation state is detected, which is made of, for example, a magnetic material. On the outer peripheral portion of the gear 1, a peak portion 1a and a valley portion 1b are formed at predetermined intervals along the rotation direction. . In order to detect the rotation state of the gear 1, for example, two sets of magnetic sensors 21 and 22 made of magnetoresistive elements are opposed to the gear 1 and have a predetermined interval along the rotation direction of the gear 1. Arrange. Each of the magnetic sensors 21 and 22 outputs a binary detection signal according to the crest 1a and trough 1b of the gear 1, respectively.

  As shown in FIG. 28, it is assumed that the case where the gear 1 rotates clockwise is normal rotation, and the reverse case is reverse rotation. In the case of forward rotation, the phase of the detection output 21a of the sensor 21 precedes the detection output 22a of the sensor 22 as shown in FIG. The phase difference between the two detection outputs 21a and 22a can be adjusted by adjusting the interval between the crest 1a and trough 1b of the gear 1 and the interval between the sensors 21 and 22. Here, the phase difference is adjusted to be a quarter cycle. Further, when the gear 1 rotates in the reverse direction, the phase of the detection output 22a of the sensor 22 precedes the detection output 21a of the sensor 21, as shown in FIG.

  The detection output 21 a is connected to the data input of a DFF (D-type flip-flop) 31, and the detection output 22 a is connected to the clock input of the DFF 31. The DFF 31 observes the data input (detection output 21a) when the clock input (detection output 22a) rises, and detects the rotation direction of the gear 1 based on the polarity. That is, as shown in FIG. 29, when the gear 1 is rotating forward, the detection output 21a is always “High” at the times t80, t81, and t82 when the detection output 22a rises. Therefore, the DFF 31 determines that the gear 1 is rotating forward and outputs “High” as the rotation direction detection result output 22r. On the other hand, as shown in FIG. 30, when the gear 1 rotates in the reverse direction, the detection output 21a is always “Low” at the times t83, t84, and t85 when the detection output 22a rises. Therefore, the DFF 31 determines that the gear 1 is rotating in the reverse direction and outputs “Low” as the rotation direction detection result output 22r.

  However, when one of the two sensors 21 and 22 becomes abnormal due to disconnection or failure, the DFF 31 makes an error in detecting the rotational direction, and the rotational direction detection output 22r becomes abnormal. That is, as shown in FIG. 31, when the gear 1 is rotating forward, for example, it is assumed that the sensor 21 has failed after time t87 and its output is always “Low”. The DFF 31 observes the sensor detection output 21a at the rising edge of the sensor detection output 22a and detects the rotation direction of the gear 1 based on the polarity thereof, so that the gear 1 is rotating forward at the timing of time t88. It is determined that reverse rotation has started.

  In order to avoid such erroneous detection, in Japanese Patent Laid-Open No. 10-122903, the detection outputs of two sensors monitor each other, and when an abnormality of one sensor signal is detected, the frequency output is stopped. Yes. FIG. 32 shows a configuration of a rotation detection device according to this publication. 32, four D-type flip-flops (DFF) 111, 113, 115, and 117, AND circuits 119 and 123, and EXOR circuits 121 and 125 are provided, and these constitute an abnormality detection unit.

  The DFF 111 and DFF 113 are used to detect an abnormality of the first position sensor MRR101, and the DFF 115 and DFF 117 are used to detect an abnormality of the second position sensor MRF102. The output of the first position sensor MRR101 is connected to the D terminal of the DFF 111, the D terminal of the DFF 113, and the CK terminal of the DFF 115. The NOT circuit 107 is connected to the output of the first position sensor MRR101, and the output of the NOT circuit 107 is connected to the CK terminal of the DFF 117.

The output of the second position sensor MRF102 is connected to the CK terminal of the DFF111, the D terminal of the DFF115, and the D terminal of the DFF117. The output of the second position sensor MRF102 is connected to the NOT circuit 109, and the output of the NOT circuit 109 is connected to the CK terminal of the DFF113.
A reset signal 105 is input to each R terminal of the DFFs 111, 113, 115, and 117. The Q output of the DFF 113 is a rotation direction output F / R. The AND circuit 119 takes a logical product of the Q output of the DFF 115 and the inverted output of Q of the DFF 111. The AND circuit 119 outputs “High” at the time of forward rotation of the rotating body, and outputs “Low” at the time of reverse rotation. The AND circuit 123 calculates the logical product of the Q output of the DFF 111 and the inverted output of Q of the DFF 115. The AND circuit 123 outputs “High” when the rotating body rotates backward, and outputs “Low” when rotating forward.

  The EXOR circuit 121 performs an exclusive OR of the Q output of the DFF 111 and the Q output of the DFF 113. The EXOR circuit 125 takes an exclusive OR of the Q output of the DFF 115 and the Q output of the DFF 117. The EXOR circuit 121 outputs “High” when the first position sensor MRR101 is normal, and outputs “Low” when the first position sensor MRR101 is abnormal. The EXOR circuit 125 outputs “High” when the second position sensor MRF102 is normal, and outputs “Low” when the second position sensor MRF102 is abnormal.

The AND circuits 127 and 129 and the DFFs 131, 133, 135, 137, 139, and 141 constitute a rotation direction determination unit.
The AND circuit 127 calculates the logical product of the output of the AND circuit 119 and the reset signal 105. The AND circuit 129 takes the logical product of the output of the AND circuit 123 and the reset signal 105. The DFFs 131, 133, and 135 are cascaded in multiple stages, and the output of the AND circuit 119 is connected to the D terminal of the DFF 131. The R terminals of the DFFs 131, 133, and 135 are connected to the output of the AND circuit 127. The CK terminals of the DFFs 131, 133, and 135 are connected to the output of the MRF 102. The DFFs 137, 139, and 141 are cascaded in multiple stages, and the output of the AND circuit 123 is connected to the D terminal of the DFF 137. Each R terminal of DFF 137, 139, 141 is connected to the output of AND circuit 129. The CK terminals of the DFFs 137, 139, 141 are connected to the output of the first position sensor MRR101.

The AND circuit 143, the AND circuit 145, and the OR circuit 147 constitute a frequency output control unit.
The AND circuit 143 calculates the logical product of the Q output of the DFF 135, the output of the EXOR circuit 121, the output of the EXOR circuit 125, and the first position sensor MRR101. The AND circuit 143 outputs the frequency output of the first position sensor MRR101 during the forward rotation of the rotating body, and becomes “Low” during the reverse rotation.
The AND circuit 145 performs a logical product of the Q output of the DFF 141, the output of the EXOR circuit 121, the output of the EXOR circuit 125, and the second position sensor MRF102. The AND circuit 145 outputs the frequency output of the second position sensor MRF102 when the rotating body rotates backward, and becomes “Low” when rotating forward.
The OR circuit 147 takes the logical sum of the output of the AND circuit 143 and the output of the AND circuit 145, and this logical sum output becomes the frequency output FO.

Hereinafter, an operation in the case where the first position sensor MRR101 fails and becomes “High” during the forward rotation of the rotating body will be described with reference to FIG.
When the first position sensor MRR101 breaks down and becomes “High”, the DFF 111 detects an abnormality at the timing of time t101, resets the DFFs 131, 133, and 135, and the time 3 pulses after returning from the failure. A frequency output is output from t102.

  On the other hand, as shown in FIG. 34, when the first position sensor MRR101 breaks down and becomes “Low”, the rotation direction output F / R is detected to be reverse rotation even though it is rotating forward. At the same time, the frequency output is output immediately after recovery from the failure. In this case, as shown in FIG. 35, if the frequency output is observed by an external circuit, and if the stop of the output is observed, a reset signal (RST) is input, the same as in FIG. After the pulse, the frequency output can be started.

Japanese Patent Laid-Open No. 10-332725 JP-A-10-122903

  However, in the rotation detection device disclosed in Patent Document 2, even when the rotation direction of the rotating body is switched, it is determined that the sensor is abnormal and the output is stopped. In recent years, in a rotational state detection device used in an engine or the like, it is necessary to grasp the rotational position of a rotating body even when the rotation is stopped. In the case of an engine, it is known that when rotation stops, it stops while vibrating for several cycles of sensor detection output. Therefore, the rotation position when the rotating body stops is grasped by repeating the normal rotation and the reverse rotation and counting how many pulses are generated in the normal rotation and how many pulses are generated in the reverse rotation. Therefore, in a device that stops frequency output when the rotation direction is reversed as in the conventional example, the number of pulses cannot be counted when rotation stops, and the rotation position of the rotating body when stopped I can't figure out.

In the rotation detection device according to the conventional example, an operation when the rotation direction is reversed from the normal rotation to the reverse rotation will be described with reference to FIG.
When the rotating body reverses from forward rotation to reverse rotation at time t103, the first position sensor signal MRR101 and the second position sensor signal MRF102 are, as shown, the second position sensor signal MRF102 before time t103. However, the phase advances with respect to the first position sensor signal MRR101, and after the time t103, the phase of the first position sensor signal MRR101 advances.

In DFFs 111, 113, 115, and 117, the polarities are inverted after time t103, so that the DFFs 131, 133, and 135 are reset, and the frequency output is stopped. Thereafter, the DFFs 137, 139, and 141 are released from the reset state, and the frequency output is resumed after a delay of three pulses.
As described above, when the rotation direction of the rotating body is reversed, the rotation detection device determines that there is an abnormality and stops frequency output.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a rotation state detection device capable of outputting an abnormality detection signal only in the case of an abnormality in a rotation detection signal of a rotating body. To do.

In order to achieve the above object, the present invention is configured as follows.
In other words, the rotational state detection device according to the first aspect of the present invention is arranged to face the rotating body, and outputs a binary detection signal in the form of two rectangular waves having different phases according to the rotation of the rotating body. 1 sensor and 2nd sensor, the 1st-4th rotation direction detection part, and the abnormality detection part were provided. The first rotation direction detection unit detects the rotation direction of the rotating body by observing the detection signal of the second sensor when the detection signal from the first sensor rises. The second rotation direction detection unit detects the rotation direction of the rotating body by observing the detection signal of the second sensor when the detection signal from the first sensor falls. The third rotation direction detection unit detects the rotation direction of the rotating body by observing the detection signal of the first sensor when the detection signal from the second sensor rises. The fourth rotation direction detection unit observes the detection signal of the first sensor when the detection signal from the second sensor falls, and detects the rotation direction of the rotating body. The abnormality detection unit is configured to detect the first sensor and the second sensor when the mismatch of the rotation direction detection results obtained from the first to fourth rotation direction detection units continues beyond a half cycle of the detection signal. It is determined that at least one of the abnormalities is detected, and an abnormality detection signal is output.

  According to the rotation state detection device of the first aspect of the present invention, the first to fourth rotation direction detection units and the abnormality detection unit are provided, and the detection results of the first to fourth rotation direction detection units are inconsistent. If it is detected, it is determined that at least one of the first sensor and the second sensor is abnormal. Therefore, when the rotation direction of the rotating body is switched, it is not determined that the sensor is abnormal, and the abnormality detection signal can be output only when the detection signal of at least one of the first sensor and the second sensor is abnormal.

  A rotation state detection apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In each figure, the same or similar components are denoted by the same reference numerals.

Embodiment 1 FIG.
The rotation state detection device of the present embodiment will be described below with reference to FIGS.
FIG. 1 is a configuration diagram of a rotation state detection device 701 according to the first embodiment.
The rotation state detection device 701 is a device that includes the first sensor 21, the second sensor 22, the rotation direction detection unit 3, and the abnormality detection unit 5 and detects the rotation state of the rotating body 1. The rotating body 1 is formed of, for example, a magnetic disk, and convex ridges 1a and concave valleys 1b are alternately formed on the outer peripheral surface thereof at predetermined intervals along the rotation direction. ing. Thus, the rotary body 1 has a gear shape as an example.

  The first sensor 21 and the second sensor 22 are sensors composed of, for example, a magnetoresistive element in order to detect the rotation state of the rotating body 1. In the present embodiment, the sensor that detects the rotation state of the rotating body 1 is, for example, two sets of sensors such as the first sensor 21 and the second sensor 22, and the first sensor 21 and the second sensor 22 are Opposing to the outer peripheral surface of the rotating body 1, the rotating body 1 is arranged at a predetermined interval along the rotating direction of the rotating body 1. Such first sensor 21 and second sensor 22 output binary detection signals 21 a and 22 a according to the crest 1 a and trough 1 b of the rotating body 1 as the rotating body 1 rotates. As shown in FIG. 1, the case where the rotating body 1 rotates clockwise is defined as forward rotation, and the case where it rotates in the opposite direction is defined as reverse rotation.

  The rotation direction detection unit 3 includes rotation direction detection results 21r and 21f indicating the rotation direction of the rotating body 1 at the rising and falling points in the detection signals 21a and 22a sent from the first sensor 21 and the second sensor 22, respectively. , 22r, 22f are output.

  FIG. 2 shows an example of the configuration of the rotation direction detection unit 3, and the rotation direction detection unit 3 includes four DFF (D-type flip-flop) circuits 31, 32, 33, and 34. Also, in the figure, the circles shown in the clock input sections of the DFF circuits 32 and 34 indicate inverted inputs, meaning that each holds data at the falling edge of the clock, and the output Qn was observed. This means outputting the inversion of the data input.

The DFF circuit 31 uses the detection signal 21a transmitted from the first sensor 21 as a data input and the detection signal 22a transmitted from the second sensor 22 as a clock input, and outputs a rotation direction detection result 22r at the rising edge of the detection signal 22a. . The DFF circuit 31 corresponds to an example of a third rotation direction detection unit.
The DFF circuit 32 uses the detection signal 21a sent from the first sensor 21 as a data input, and uses the inversion of the detection signal 22a sent from the second sensor 22 as a clock input, and the rotation direction detection result 22f at the falling edge of the detection signal 22a. Is output. The DFF circuit 32 corresponds to an example of a fourth rotation direction detection unit.

The DFF circuit 33 uses the detection signal 22a sent from the second sensor 22 as a data input and the detection signal 21a sent from the first sensor 21 as a clock input, and outputs a rotation direction detection result 21r when the detection signal 21a rises. . The DFF circuit 33 corresponds to an example of a first rotation direction detection unit.
The DFF circuit 34 uses the detection signal 22a sent from the second sensor 22 as a data input, and uses the inversion of the detection signal 21a sent out from the first sensor 21 as a clock input to detect the rotation direction detection result 21f when the detection signal 21a falls. Is output. The DFF circuit 34 corresponds to an example of a second rotation direction detection unit.

  Based on the rotation direction detection results 21r, 21f, 22r, and 22f sent from the rotation direction detection unit 3, the abnormality detection unit 5 determines whether the abnormality detection signal 5a and the detection signal 21a are abnormal, in other words, the first sensor. An abnormality detection signal 21e indicating whether 21 is abnormal and an abnormality detection signal 22e indicating whether the detection signal 22a is abnormal, in other words, whether the second sensor 22 is abnormal are output. The abnormality detection signal 21e and the abnormality detection signal 22e correspond to the individual abnormality detection signals of the first sensor 21 and the second sensor 22, respectively. Further, as described below, the abnormality detection signal 5a is a signal indicating an abnormality when at least one of the abnormality detection signal 21e and the abnormality detection signal 22e indicates an abnormality.

  FIG. 3 shows an example of the configuration of the abnormality detection unit 5. The abnormality detection unit 5 receives the detection signals 21a and 22a and the rotation direction detection results 21r, 21f, 22r, and 22f as inputs, and the rotation direction detection results 21r and 21f at the rising and falling edges of the detection signals 21a and 22a, respectively. , 22r, 22f are observed, and when the mismatch continues, it is determined that there is an abnormality, and the abnormality detection signal 5a and the abnormality detection signals 21e, 22e of the first sensor 21 and the second sensor 22 are output. Below, the specific structure of the abnormality detection part 5 is demonstrated.

The EXOR circuit 501 performs an exclusive OR of the rotation direction detection results 22r and 22f, detects a mismatch between the rotation direction detection results 22r and 22f at the rise and fall of the detection signal 22a, and “High” when there is a mismatch. Is output.
The EXOR circuit 502 takes an exclusive OR of the rotation direction detection results 21r and 21f and detects a mismatch between the rotation direction detection results 21r and 21f at the rise and fall of the detection signal 21a. Is output.

The DFF 503 uses the output of the EXOR circuit 501 as a data input, the detection signal 22a of the second sensor 22 as a clock input, and whether or not the discrepancy between the rotation direction detection results 22r and 22f at the rise and fall of the detection signal 22a continues. Is determined.
The DFF 504 uses the output of the EXOR circuit 501 as a data input and the inversion of the detection signal 22a of the second sensor 22 as a clock input, and the discrepancy between the rotation direction detection results 22r and 22f at the rise and fall of the detection signal 22a continues. It is determined whether or not.

The DFF 505 receives the output of the EXOR circuit 502 as a data input, receives the detection signal 21a of the first sensor 21 as a clock input, and whether or not the discrepancy between the rotation direction detection results 21r and 21f at the rise and fall of the detection signal 21a continues. Is determined.
The DFF 505 uses the output of the EXOR circuit 502 as a data input and the inversion of the detection signal 21a of the first sensor 21 as a clock input, and the discrepancy between the rotation direction detection results 21r and 21f at the rise and fall of the detection signal 21a continues. It is determined whether or not.

The AND circuit 511 takes the logical product of the DFFs 503 and 504, and outputs “High” as the abnormality detection signal 22e because the second sensor 22 is abnormal when both are “High”.
The AND circuit 516 calculates the logical product of the DFFs 505 and 506, and when both are “High”, the first sensor 21 is abnormal, and therefore outputs “High” as the abnormality detection signal 21e.

  The OR circuit 519 calculates the logical sum of the abnormality detection signals 21e and 22e, and outputs “High” when either becomes “High”.

  The above-described components of the EXOR circuit 501, the EXOR circuit 502, the DFFs 503 to 506, and the AND circuits 511 and 516 have a determination unit 5b that determines which of the first sensor 21 and the second sensor 22 is abnormal. Serves as a function.

The operation of the rotation state detection device 701 according to the first embodiment configured as described above will be described below with reference to the drawings.
FIG. 4 shows the waveform of each part when the detection signal 21a of the first sensor 21 is abnormal and always becomes “High” in a state where the rotating body 1 is rotating forward.

  When the detection signal 21a is always “High”, the rotation direction detection result 22r when the detection signal 22a of the second sensor 22 rises is always “High”. However, the rotation direction detection result 22f when the detection signal 22a falls is “Low” indicating reverse rotation from time t01 to time t03 when the detection signal 21a is abnormal. Since the detection signal 21a does not change while the detection signal 21a is abnormal, the rotation direction detection results 21r and 21f always remain “High”. Accordingly, between time t01 and time t03, the rotational direction detection results 22r and 22f are inconsistent, that is, the EXOR circuit 501 is “High”, and the rotational direction detection results 21r and 21f are inconsistent, that is, the EXOR circuit 502 is “Low”. is there.

  When the abnormality of the detection signal 21a continues, the outputs of the DFFs 503 and 504 both become “High”, and the abnormality detection signal 22e obtained by ANDing outputs “High” from time t02 to time t04. The mismatch between the rotation direction detection results 21r and 21f, that is, the EXOR circuit 502 remains “Low”, so that the outputs of the DFFs 505 and 506 and the output of the AND circuit 516 are always “Low”. Therefore, the abnormality detection signal 5a outputs “High” between the times t02 and t04.

Next, in FIG. 5, the waveform of each part when the rotation direction of the rotary body 1 is reversed from normal rotation to reverse rotation is shown.
When the rotation direction of the rotating body 1 is reversed from normal rotation to reverse rotation, the detection signals 21a and 22a have waveforms as shown in the figure, for example. In the four DFF circuits 31, 32, 33, and 34, the rotation direction detection result 21r at the rise of the detection signal 21a detects inversion at time t08, and the rotation direction detection result 21f at the fall of the detection signal 21a. Detects inversion at time t06. The rotation direction detection result 22r at the rise of the detection signal 22a detects inversion at time t07, and the rotation direction detection result 22f at the fall of the detection signal 22a detects inversion at time t05.

  Accordingly, a section in which the rotational direction detection results 21r and 21f do not match, that is, a section in which the EXOR circuit 502 becomes “High” is between time t06 and time t08, and a section in which the rotational direction detection results 22r and 22f do not match, ie, the EXOR circuit The section in which 501 becomes “High” is between time t05 and time t07. Since these sections are the half periods of the detection signals 21a and 22a, respectively, if this signal is held in the DFFs 503, 504, 505, and 506 at the rising and falling timings of the detection signals 21a and 22a, the DFF 503 and the DFF 504, Each of the DFF 505 and the DFF 506 does not become “High” at the same time. Therefore, the abnormality detection signals 21e and 22e are always “Low”, and the abnormality detection signal 5e is always “Low”.

As described above, according to the rotation state detection device 701 of the first embodiment, it is not determined that there is an abnormality because the rotation direction of the rotating body 1 is reversed, and at least of the first sensor 21 and the second sensor 22. Only when one of the detection signals becomes abnormal, the abnormality detection signal can be output.
Further, according to the rotation state detection device 701 of the first embodiment, as is apparent from the configuration of the abnormality detection unit 5 shown in FIG. 3, either the first sensor 21 or the second sensor 22 is abnormal. Can be determined.

Embodiment 2. FIG.
Next, a rotation state detection apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS.
FIG. 6 shows another configuration example of the abnormality detection unit 5 shown in FIG. The abnormality detection unit 5c shown in FIG. 6 has a configuration in which a logic circuit is added to the abnormality detection unit 5 shown in FIG. 1, and the abnormality detection unit 5c has a configuration that accelerates the abnormality detection timing. In FIG. 6, the components of the EXOR circuit 501, EXOR circuit 502, DFFs 503 to 506, and AND circuits 511 and 516 are the same as those shown in FIG.

Reference numerals 507 to 510 and reference numerals 512 to 515 denote AND circuits, which perform a logical product when an abnormality occurs, and generate timing that is half a cycle earlier than the abnormality detection timing described in the first embodiment. In the drawing, the circles of the input sections in the AND circuits 507 to 510 and the AND circuits 512 to 515 mean that the signals are inverted and input.
Reference numerals 517, 518, 520, and 521 denote OR circuits, which are ORed in each case to detect an abnormality detection signal 5a that is half a cycle earlier than the abnormality detection timing shown in the first embodiment, and abnormality detection signals 21e and 22e. Is generated.

The operation of the abnormality detection unit 5c configured as described above will be described below with reference to FIGS.
FIG. 7 shows the timing of each signal when the first sensor 21 fails and the detection signal 21a always outputs “High” when the rotating body 1 is rotating forward.
As shown in FIG. 7, when the rotator 1 is rotating forward, the phase of the detection signal 21a is more advanced than that of the detection signal 22a, and the rotation direction detection results 21r, 21f, 22r, and 22f are all “High”. . In this state, if the first sensor 21 breaks down and the detection signal 21a always becomes “High”, the rotation direction detection result 22f at the fall of the detection signal 22a becomes “Low” at the timing of time t09, and the detection signal 22a. This is inconsistent with the rotation direction detection result 22r at the time of rising.

  The EXOR circuit 501 detects this mismatch and outputs “High” at time t09. Accordingly, the outputs of the DFFs 503 and 504 become “High” at the timings t10 and t11, respectively, and the AND circuit 508 outputs “High” from the time t10 to the time t11. As described above, the OR circuit 517 takes these logical sums and outputs “High” from time t10 to time t12. Therefore, the abnormality detection signal 5a and the abnormality detection signal 22e detect an abnormality at a timing t10 that is half a cycle earlier than the time t02 (time t11 in FIG. 7) that is the detection timing in the first embodiment shown in FIG. it can.

Next, an operation when the rotation direction of the rotating body 1 is reversed from the normal rotation to the reverse rotation will be described with reference to FIG.
As in the case of the first embodiment shown in FIG. 5, when the rotation direction of the rotating body 1 is reversed from normal rotation to reverse rotation, the detection signals 21a and 22a have waveforms as shown in the figure, for example. The four DFF circuits 31, 32, 33, and 34 detect inversion at times t16, t14, t17, and t15, respectively. Accordingly, a section in which the rotational direction detection results 21r and 21f do not match, that is, a section in which the EXOR circuit 502 becomes “High” is between time t15 and time t17, and a section in which the rotation direction detection results 22r and 22f do not match, that is, the EXOR circuit. The section in which 501 becomes “High” is between time t14 and time t16. These sections are for half periods of the detection signals 21a and 22a, respectively.

  Therefore, if this signal is held in the DFFs 503, 504, 505, and 506 at the rising and falling timings of the detection signals 21a and 22a, the DFF 503 and the DFF 504, and the DFF 505 and the DFF 506 are not simultaneously “High”. Therefore, since the AND circuits 511 and 516 are always “Low”, and the AND circuits 507 to 510 and the AND circuits 512 to 515 are also always “Low”, the abnormality detection signals 21e and 22e are always “Low”. The abnormality detection signal 5e is always “Low”.

  As described above, even with the rotation state detection device according to the second embodiment, it is not determined that the rotation direction of the rotating body 1 is reversed, so that it is not abnormal, and at least one of the first sensor 21 and the second sensor 22 is not detected. Only when the detection signal becomes abnormal, an abnormality detection signal indicating abnormality can be output.

Embodiment 3 FIG.
Next, a rotation state detection apparatus according to Embodiment 3 of the present invention will be described with reference to FIGS.
FIG. 9 is a configuration diagram of the rotation state detection device 703 according to the third embodiment. The rotation state detection device 703 has a configuration in which a rotation speed output control unit 6a corresponding to a first rotation number output control unit is added to the rotation state detection device 701 shown in FIG. 1 described above.

  In response to the abnormality detection signal 5a, the rotation speed output control unit 6a outputs the output of the detection signal 22a from the second sensor 22 as a rotation speed counting signal in the case of normality. It is a control part which stops an output.

  FIG. 10 shows an example of the configuration of the rotation speed output control unit 6a, which is configured by an AND circuit. When the output 5a of the abnormality detection unit 5 is “Low”, that is, when it is normal, the AND circuit 601 outputs the sensor detection signal 22a as it is, the abnormality detection unit 5 detects the abnormality, and the abnormality detection signal 5a is “High”. When "", the output is fixed to "Low".

  FIG. 11 shows the timing of the output signal when the first sensor 21 fails and the detection signal 21a always outputs “High” when the rotating body 1 is rotating forward. When the detection signal 21a becomes abnormal, the abnormality detection unit 5 detects the abnormality and outputs “High” from time t18 to time t19. The rotation speed output control unit 6a stops outputting the detection signal 22a and outputs “Low” between time t18 and time t19. That is, two pulses indicated by broken lines are masked.

  If the abnormality detection unit 5c according to the second embodiment shown in FIG. 6 is used, as shown in FIG. 12, the abnormality detection signal 5a detects an abnormality from time t20 to time t21. Therefore, the rotation speed output control unit 6a stops outputting the sensor detection signal 22a from time t20 to time t21 and outputs “Low”. That is, the three pulses indicated by the broken lines are masked.

  Further, if the AND circuit 602 as shown in FIG. 13 is used as the rotation speed output control unit 6a and the abnormality detection unit 5 according to the first embodiment shown in FIG. 3 is used, an abnormality is detected as shown in FIG. Between the detected time t22 and time t23, the fixed output is “High”. Further, if the abnormality detection unit 5c according to the second embodiment shown in FIG. 6 is used, as shown in FIG. 15, a fixed output of “High” is obtained between time t24 and time t25 when the abnormality is detected. .

As described above, according to the rotation state detection device 703 of the third embodiment, the rotation speed output can be continued even when the sensor fails. Further, by switching the output level of the rotation speed output control unit 6a according to the abnormality detection result, the rotation speed information and the abnormality detection information can be transmitted through one signal line.
Further, it is possible to prevent an erroneous signal from being notified when the sensor fails and an abnormal output is generated.

  Here, as described above, the output of the detection signal 22a is output as the rotation speed counting signal in the normal state, but instead of using the detection signal 22a by the second sensor 22, the detection by the first sensor 21 is performed. It can also be configured using the signal 21a. In this case, when normal, the rotational speed output control unit 6a outputs the output of the detection signal 21a from the first sensor 21 as a rotational speed counting signal, and stops the output when an abnormality occurs.

Embodiment 4 FIG.
Next, a rotation state detection apparatus according to Embodiment 4 of the present invention will be described with reference to FIGS.
FIG. 16 is a configuration diagram of the rotation state detection device 704 according to the fourth embodiment. The rotational state detection device 704 has a configuration in which a rotational speed output control unit 6b corresponding to a second rotational speed output control unit is added to the rotational state detection device 701 shown in FIG. 1 described above.

  In response to the abnormality detection signal 22e of the second sensor 22, the rotation speed output controller 6b outputs the output of the detection signal 22a from the second sensor 22 as a rotation speed counting signal in the case of normality, and the sensor 22a This is a rotation speed output control unit that switches the output of the detection signal 22a to the output of the detection signal 21a of the first sensor 21 when an abnormality occurs in the output.

  FIG. 17 shows an example of the configuration of the rotation speed output control unit 6b. The rotation speed output control unit 6 b is configured by a selector circuit 603. The selector circuit 603 is supplied with a detection signal 21a from the first sensor 21 and a detection signal 22a from the second sensor 22, and an abnormality detection signal 22e from the second sensor 22 as a signal for selecting the detection signals 21a and 22a. Supplied.

  When the abnormality detection signal 22e of the second sensor 22 is “Low”, that is, when the second sensor 22 is normal, the rotation speed output control unit 6b has the detection signal 22a of the second sensor 22 as it is. Output as a counting signal. On the other hand, when the abnormality detection unit 5 detects the abnormality of the second sensor 22 and the abnormality detection signal 22e of the second sensor 22 becomes “High”, the rotation speed output control unit 6b detects the detection signal of the second sensor 22. 22a is switched to the detection signal 21a of the first sensor 21 and output as a rotation speed counting signal.

  In this example, the detection signal 21a of the first sensor 21 and the detection signal 22a of the second sensor 22 are switched based on the abnormality detection signal 22e of the second sensor 22, but the abnormality detection of the first sensor 21 is detected. The detection signal 21a of the first sensor 21 and the detection signal 22a of the second sensor 22 can be switched based on the signal 21e.

  FIG. 18 shows the timing of the output signal when the second sensor 22 fails and always outputs “High” when the rotating body 1 is rotating forward. The abnormality detection unit 5 detects an abnormality in the detection signal 22a of the second sensor 22 from time t26 to time t27, and outputs “High”. In the rotation speed output control unit 6b, when the second sensor 22 is normal, that is, while the abnormality detection signal 22e of the second sensor 22 is “Low”, the selector circuit 603 detects the detection signal 22a by the second sensor 22 of the B terminal. When the second sensor 22 is abnormal, that is, while the abnormality detection signal 22e of the second sensor 22 is “High”, the detection signal 21a by the first sensor 21 of the A terminal is selected and output.

  As described above, according to the rotation state detection device 704 according to the fourth embodiment, even if one of the sensors malfunctions, it can be switched to the normal sensor output, and the rotation speed detection signal 6x is output without interruption. can do.

  FIG. 19 shows another configuration example of the rotation speed output control unit 6b shown in FIG. The rotation speed output control unit 6b-1 shown in FIG. 19 corresponds to an example that fulfills the function of the output level changing unit. When the second sensor 22 is abnormal, the output is switched to the detection signal 21a of the first sensor 21. At the same time, the “Low” level of the output of the rotation speed output control unit 6b-1 is output at a level different from the normal level. As described above, the rotation speed output control unit 6b-1 can notify that the detection signal 22a by the second sensor 22 is abnormal without interrupting the rotation speed detection signal 6x.

The configuration of the rotation speed output control unit 6b-1 will be described. Reference numeral 604 is an input of inversion of the abnormality detection signal 22e of the second sensor 22 and inversion of the detection signal 22a by the second sensor 22, and when the second sensor 22 is normal and the detection signal 22a is "Low". , An AND circuit that outputs a signal for turning on the transistor circuit 606. Reference numeral 605 inputs an abnormality detection signal 22e of the second sensor 22 and an inversion of the detection signal 21a by the first sensor 21, and when the second sensor 22 is abnormal and the detection signal 21a is "Low" This is an AND circuit that outputs a signal for turning on the transistor circuit 607. The transistor circuit 606 is turned on when the output of the AND circuit 604 is “High”. The transistor circuit 607 is turned on when the output of the AND circuit 605 is “High”.
The operation of the rotation speed output control unit 6b-1 will be described below with reference to FIG.

Since the abnormality detection signal 22e of the second sensor 22 is “Low” when normal, the AND circuit 604 outputs “High” while the detection signal 22a of the second sensor 22 is “Low”, and the AND circuit 605 Is always “Low”. The transistor circuit 606 is turned on by the AND circuit 604 while the detection signal 22a from the second sensor is “Low”, and the transistor circuit 607 is always turned off. Therefore, the point A is at the same level as GND while the detection signal 22a from the second sensor 22 is “Low”. Accordingly, the “Low” level V0 of the rotation speed detection signal 6x at the normal time is
V0 = (R1 / (R0 + R1)) × Vcc
It becomes. Here, R0 and R1 are resistance values of the resistors R0 and R1 shown in FIG.

Further, when the abnormality detection unit 5 detects an abnormality of the second sensor 22, the abnormality detection signal 22e of the second sensor 22 becomes “High”. Therefore, the AND circuit 604 always outputs “Low”, and the AND circuit 605 outputs “High” while the detection signal 21a from the first sensor 21 is “Low”. The transistor circuit 606 is always turned off, and the transistor circuit 607 is turned on by the AND circuit 605 while the detection signal 21a from the first sensor 21 is “Low”. Therefore, at the point A, the detection signal 21a is “Low”. Is connected to GND via a resistor R2. Therefore, the “Low” level V1 of the rotation speed detection signal 6x when the detection signal 22a of the second sensor 22 is abnormal is:
V1 = ((R1 + R2) / (R0 + R1 + R2)) × Vcc
It becomes. Here, R0, R1, and R2 are resistance values of the resistors R0, R1, and R2 shown in FIG.

  During normal operation, the detection signal 22a of the second sensor 22 is “High”, or when the detection signal 21a of the first sensor 21 is “High” when the second sensor 22 is abnormal, the transistor circuit 606 Since both 607 are off, the level of the rotational speed detection signal 6x is the same as Vcc.

  Here, for example, if Vcc = 5V, R0 = 10 kilohms, R1 = 1 kiloohms, and R2 = 6 kiloohms, the respective output voltages are about V0 = 0.5V and V1 = 2V. Therefore, in the subsequent signal processing circuit that receives the rotational speed detection signal 6x, the rotational speed of the rotating body 1 can be measured by setting Vth0 = 2.5V, for example, and Vth1 = 1. By setting the voltage to about 5 V, the abnormal state of the sensor can also be observed.

  Thus, according to the rotation speed output control part 6b-1, even if a sensor breaks down, while continuing rotation speed output, it can notify that the sensor is broken.

  In the above example, the abnormality detection signal 22e is described as an example when the second sensor 22 is abnormal. Instead, the first sensor 21 is configured using the abnormality detection signal 21e when the first sensor 21 is abnormal. You may do it. In this case, the inversion of the abnormality detection signal 21e of the first sensor 21 and the detection signal 21a of the first sensor 21 are input to the AND circuit 604, and the abnormality detection signal 21e of the first sensor 21 is input to the AND circuit 605. And the inversion of the detection signal 22a of the second sensor 22.

Embodiment 5 FIG.
Next, a rotation state detection device according to a fifth embodiment of the present invention will be described with reference to FIGS.
FIG. 21 is a configuration diagram of the rotation state detection device 705 according to the fifth embodiment. In addition to the configuration of the rotation state detection device 704 in the fourth embodiment shown in FIG. 16, the rotation state detection device 705 further inputs the abnormality detection signal 21e of the first sensor 21 to the rotation speed output control unit. The configuration is as follows. Reference numeral 6c is assigned to the rotation speed output control unit provided in the rotation state detection device 705 of the fifth embodiment. Other configurations are the same as the configuration of the rotation state detection device 704. The rotation speed output control unit 6c corresponds to an example that performs the function of the third rotation speed output control unit.

  FIG. 22 shows an example of the configuration of the rotation speed output control unit 6c shown in FIG. In addition, in the rotation speed output control unit 6c, a portion surrounded by a dotted line corresponds to an example of performing the function of the output level changing unit, and is denoted by reference numeral 6c-1. The rotation speed output control unit 6c is different from the rotation speed output control unit 6b of the fourth embodiment shown in FIG. 19 in addition to the case where the detection signal 22a of the second sensor 22 is abnormal, and the detection signal 21a of the first sensor 21. Even in the case of an abnormality, the “Low” level of the output of the rotation speed output control unit 6c is output at a level different from the normal level. Therefore, according to the rotation state detection device 705, it is possible to notify that any of the detection signals 21a and 22a of the first sensor 21 and the second sensor 22 is abnormal without interrupting the rotation speed detection signal 6x. It is a thing.

The configuration of the output level changing unit 6c-1 in the rotation speed output control unit 6c will be described.
Reference numeral 608 is a normal and detection signal 22a that receives the inversion of the abnormality detection signal 21e of the first sensor 21, the inversion of the abnormality detection signal 22e of the second sensor 22, and the inversion of the detection signal 22a of the second sensor 22. Is an AND circuit that outputs a signal to turn on the transistor circuit 606 when “Low”. Reference numeral 605 inputs an abnormality detection signal 22e of the second sensor 22 and an inversion of the detection signal 21a by the first sensor 21, and when the second sensor 22 is abnormal and the detection signal 21a is "Low" This is an AND circuit that outputs a signal for turning on the transistor circuit 607. Reference numeral 609 receives an abnormality detection signal 21e of the first sensor 21 and an inversion of the detection signal 22a of the second sensor 22, and when the first sensor 21 is abnormal and the detection signal 22a is "Low" This is an AND circuit that outputs a signal for turning on the transistor circuit 610. The transistor circuit 606 is turned on when the output of the AND circuit 608 is “High”. The transistor circuit 607 is turned on when the output of the AND circuit 605 is “High”. The transistor circuit 610 is turned on when the output of the AND circuit 609 is “High”.

The operation of the rotation speed output control unit 6c will be described below with reference to FIG.
Since the abnormality detection signal 21e of the first sensor 21 is “Low” and the abnormality detection signal 22e of the second sensor 22 is “Low” at the normal time, the AND circuit 608 detects the detection signal 22a of the second sensor 22. Is “Low”, “High” is output, and the AND circuits 605 and 609 are always “Low”. The transistor circuit 606 is turned on by the AND circuit 608 while the detection signal 22a is “Low”, and the transistor circuits 607 and 610 are always turned off. Therefore, the point A is at the same level as GND while the detection signal 22a from the second sensor 22 is “Low”. Accordingly, the “Low” level V0 of the rotation speed detection signal 6x at the normal time is
V0 = (R1 / (R0 + R1)) × Vcc
It becomes. Here, R0 and R1 are resistance values of the resistors R0 and R1 shown in FIG.

When the abnormality detection unit 5 detects an abnormality of the second sensor 22, the abnormality detection signal 21e of the first sensor 21 is "Low" and the abnormality detection signal 22e of the second sensor 22 is "High". 608 and 609 always output “Low”, and the AND circuit 605 outputs “High” while the detection signal 21a from the first sensor 21 is “Low”. Further, the transistor circuits 606 and 610 are always off, and the transistor circuit 607 is turned on by the AND circuit 605 while the detection signal 21a is “Low”. Therefore, the point A has the detection signal 21a “Low”. Meanwhile, it is connected to GND through a resistor R2. Accordingly, the “Low” level V1 of the rotation speed detection signal 6x when the detection signal 22a by the second sensor 22 is abnormal is:
V1 = ((R1 + R2) / (R0 + R1 + R2)) × Vcc
It becomes. Here, R0, R1, and R2 are resistance values of the resistors R0, R1, and R2 shown in FIG.

Further, when the abnormality detection unit 5 detects an abnormality of the first sensor 21, the abnormality detection signal 21e of the first sensor 21 becomes "High" and the abnormality detection signal 22e of the second sensor 22 becomes "Low". Therefore, the AND circuits 608 and 605 always output “Low”, and the AND circuit 609 outputs “High” while the detection signal 22a from the second sensor 22 is “Low”. The transistor circuits 606 and 607 are always off, and the transistor circuit 610 is turned on by the AND circuit 609 while the detection signal 22a is “Low”. Therefore, the point A is connected to the GND via the resistor R3 while the detection signal 22a is “Low”. Therefore, the “Low” level V2 of the rotation speed detection signal 6x when the detection signal 21a by the first sensor 21 is abnormal is:
V2 = ((R1 + R3) / (R0 + R1 + R3)) × Vcc
It becomes. Here, R0, R1, and R3 are resistance values of the resistors R0, R1, and R3 shown in FIG.

  Here, for example, assuming that Vcc = 5V, R0 = 10 kiloohms, R1 = 1 kiloohm, R2 = 6 kiloohms, and R3 = 14 kiloohms, the respective output voltages are about V0 = 0.5V, V1 = 2V, V2 = 3V. It becomes. Therefore, in the subsequent signal processing circuit that receives the signal of the rotational speed detection signal 6x, the rotational speed of the rotating body 1 can be measured by setting Vth0 = 3.5 V, for example, and Vth1 = 1. By setting 5V and Vth2 = about 2.5V, the abnormal states of both the first and second sensors can be observed.

  As described above, according to the rotation state detection device 705 of the fifth embodiment, even if a sensor breaks down, the rotation speed output can be continued, and further, which sensor is broken down can be notified. it can.

  In the fourth and fifth embodiments, the “Low” level of the rotational speed detection output 6x is switched to V0, V1, and V2. However, the configurations of the AND circuit and the transistor circuit of the rotational speed output control unit are different. It may be changed and the “High” level of the rotation speed detection output 6x may be switched in several steps. Further, both the “Low” level and the “High” level of the rotation speed detection output 6x may be switched.

Embodiment 6 FIG.
Next, a rotational state detection apparatus according to Embodiment 6 of the present invention will be described below with reference to FIGS.
The rotation state detection device 706 according to the sixth embodiment includes the first sensor 21, the second sensor 22, the rotation direction detection unit 3, and the abnormality detection unit 5 shown in FIG. 21, and further outputs the rotation speed shown in FIG. A rotation speed output control unit 6d is provided instead of the control unit 6c. A detection signal 21a from the first sensor 21, a detection signal 22a from the second sensor 22, an abnormality detection signal 21e from the first sensor 21, and an abnormality detection signal 22e from the second sensor 22 are supplied to the rotation speed output control unit 6d. The

  The rotational speed output control unit 6d is another configuration example of the rotational speed output control unit 6c shown in FIG. 21, and is normal, when the sensor detection signal 21a is abnormal, and when the sensor detection signal 22a is abnormal. In this case, different numbers of pulses are superimposed.

  As shown in FIG. 24, the rotational speed output control section 6d is roughly divided into a selector section 603 corresponding to the second rotational speed output control section as shown in FIG. 17, a pulse generating section 611, a pulse generating section 611, and a pulse generating section 611. And a superimposing unit 6d-1.

  One of the abnormality detection signals 21e and 22e of the first sensor 21 and the second sensor 22 is supplied from the abnormality detection unit 5 to the selector unit 603 as a selection signal. In the sixth embodiment, as shown in FIG. 24, a configuration in which an abnormality detection signal 22e of the second sensor 22 is supplied as a selection signal is adopted. Furthermore, the selector unit 603 is supplied with the detection signals 21a and 22a from the first sensor 21 and the second sensor 22, and when the abnormality detection signal is supplied, the first sensor 21 or the second sensor 22 that is normal. Based on the detection signals 21a and 22a, a rotation speed detection signal indicating the rotation speed of the rotating body 1 is output.

The pulse generator 611 generates a pulse having a frequency faster than the rotational speed of the rotating body 1.
The pulse superimposing unit 6d-1 is supplied with the abnormality detection signals 21e and 22e of the first sensor 21 and the second sensor 22 from the abnormality detection unit 5, and detects the number of revolutions generated by the pulse generation unit 611. It is superimposed on the signal and output.

The configuration of the rotation speed output control unit 6d will be described more specifically.
As described above, the selector unit 603 receives the detection signals 21a and 22a, and when the detection signal 22a is abnormal, that is, when the abnormality detection signal 22e of the second sensor 22 is “High”, the detection by the first sensor 21 is performed. The signal 21a is output, and when the detection signal 21a is otherwise abnormal or when the detection signal 21a is abnormal, that is, when the abnormality detection signal 21e of the first sensor 21 is “High”, the detection signal 22a of the second sensor 22 is selected and output. Circuit.

  As shown in FIG. 25, the pulse generator 611 outputs three pulses 611a, 611b, and 611c having a predetermined phase difference with a sufficiently long fixed period regardless of the number of rotations of the rotating body 1. The pulse width of these pulses is sufficiently shorter than the shortest pulse width of the rotation speed detection signal 6x.

Reference numeral 612 receives the abnormality detection signal 21e of the first sensor 21 and the abnormality detection signal 22e of the second sensor 22, and outputs “High” when either the first sensor 21 or the second sensor 22 is abnormal. OR circuit to perform.
Reference numeral 613 receives the output of the OR circuit 612 and the pulse 611b output from the pulse generator 611, and when the output of the OR circuit 612 is "High", that is, one of the first sensor 21 and the second sensor 22. Is an AND circuit that outputs a pulse 611b when is abnormal.

Reference numeral 614 receives the abnormality detection signal 22e of the second sensor 22 and the pulse 611c output from the pulse generator 611, and when the abnormality detection signal 22e of the second sensor 22 is “High”, that is, the second sensor 22. This is an AND circuit that outputs a pulse 611c when is abnormal.
Reference numeral 615 denotes an OR circuit that outputs “High” when any of the pulse 611 a output from the pulse generator 611, the output of the AND circuit 613, and the output of the AND circuit 614 is “High”.

Reference numeral 616 denotes an EXOR circuit that receives the output of the selector circuit 603 and the output of the OR circuit 615, superimposes the abnormality detection result on the output of the selector circuit 603, and outputs the rotation speed detection signal 6x.
The OR circuit 612, the AND circuits 613 and 614, the OR circuit 615, and the EXOR circuit 616 described above constitute the pulse superimposing unit 6d-1.

The operation of the rotational speed output control unit 6d configured as described above will be described below with reference to FIGS.
FIG. 25 is a timing chart of the signals of the respective parts at the normal time. Since the abnormality detection signal 21e of the first sensor 21 and the abnormality detection signal 22e of the second sensor 22 are both “Low” at normal time, the AND circuits 613 and 614 always output “Low”. Therefore, the OR circuit 615 outputs only one pulse of the pulse 611a, and the rotation speed detection signal 6x is inverted by one pulse with respect to the detection signal 22a by the second sensor 22 at a predetermined interval.

  FIG. 26 is a timing chart of each signal when the first sensor 21 is abnormal. When the first sensor 21 is abnormal, the abnormality detection signal 21e of the first sensor 21 is “High”, so the output of the OR circuit 612 is “High” and the AND circuit 613 outputs the pulse 611b. Accordingly, two pulses of pulses 611a and 611b are continuously output from the OR circuit 615, and the rotation speed detection signal 6x is inverted by two pulses with respect to the detection signal 22a by the second sensor 22 at a predetermined interval. Is done.

  FIG. 27 is a timing diagram of each signal when the second sensor 22 is abnormal. When the second sensor 22 is abnormal, the abnormality detection signal 22e of the second sensor 22 is “High”, so the output of the OR circuit 612 is “High” and the AND circuit 613 outputs the pulse 611b. Further, a pulse 611c is also output from the AND circuit 614. Accordingly, three pulses of pulses 611a, 611b, and 611c are continuously output from the OR circuit 615, and the rotation speed detection signal 6x is output at a predetermined interval with respect to the detection signal 21a by the first sensor 21. Inverted minutes.

  As described above, according to the rotation state detection device 706 in the sixth embodiment, only one pulse is obtained when it is normal, two pulses when the first sensor 21 is abnormal, and when the second sensor 22 is abnormal. The signal for three pulses is inverted with respect to the detection signal of one of the first sensor 21 and the second sensor 22. Therefore, by observing the number of inverted pulses, it is possible to determine whether it is normal, the first sensor 21 is abnormal, or the second sensor 22 is abnormal. In addition, according to the rotation state detection device 706 in the sixth embodiment, according to the abnormality detection result, the number of pulses superimposed on the output of the rotation speed output control unit 6c is switched, so that the rotation speed information and the single signal line are changed. There is an effect that the abnormality detection information can be transmitted.

  In addition, you may comprise a rotation state detection apparatus by combining the structure in each embodiment mentioned above suitably.

It is a block diagram of the rotation state detection apparatus in Embodiment 1 of this invention. It is a figure which shows an example of a structure of the rotation direction detection part shown in FIG. It is a figure which shows an example of a structure of the abnormality detection part shown in FIG. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 1, and is a timing chart of each part signal when a 1st sensor becomes abnormal when a rotary body is carrying out normal rotation. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 1, and is a timing chart of each part signal when a rotary body reverses from normal rotation to reverse rotation. It is a figure which shows the structural example of the abnormality detection part with which the rotation state detection apparatus in Embodiment 2 of this invention is equipped. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 6, and is a timing chart of each part signal when a 1st sensor becomes abnormal when the rotary body is carrying out normal rotation. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 6, and is a timing chart of each part signal when a rotary body reverses from normal rotation to reverse rotation. It is a block diagram of the rotation state detection apparatus in Embodiment 3 of this invention. It is a figure which shows an example of a structure of the rotation speed output control part shown in FIG. 9 is a timing chart for explaining the operation when the abnormality detection unit shown in FIG. 1 is used in the rotation state detection device shown in FIG. 9, and the first sensor is abnormal when the rotating body is rotating forward. It is a timing chart of each part signal at the time of becoming. 9 is a timing chart for explaining the operation when the abnormality detection unit shown in FIG. 6 is used in the rotation state detection device shown in FIG. 9, and the first sensor is abnormal when the rotating body is rotating forward. It is a timing chart of each part signal at the time of becoming. It is a figure which shows another structural example of a structure of the rotation speed output control part shown in FIG. 9 is a timing chart for explaining the operation when the abnormality detection unit shown in FIG. 1 is used and the rotation speed output control unit shown in FIG. 13 is used in the rotation state detection device shown in FIG. It is a timing chart of each part signal when the 1st sensor becomes abnormal while performing. 9 is a timing chart for explaining the operation when the abnormality detection unit shown in FIG. 6 is used and the rotation speed output control unit shown in FIG. 13 is used in the rotation state detection device shown in FIG. It is a timing chart of each part signal when the 1st sensor becomes abnormal while performing. It is a block diagram of the rotation state detection apparatus in Embodiment 4 of this invention. It is a figure which shows an example of a structure of the rotation speed output control part shown in FIG. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 16, and is a timing chart of each part signal when a 2nd sensor becomes abnormal when a rotary body is carrying out normal rotation. It is a figure which shows another structural example of the rotation speed output control part shown in FIG. It is a timing chart which shows operation | movement of the rotation state detection apparatus provided with the rotation speed output control part shown in FIG. 16, and the timing of each part signal when a 2nd sensor becomes abnormal when the rotary body is carrying out normal rotation. It is a chart. It is a block diagram of the rotation state detection apparatus in Embodiment 5 of this invention. It is a figure which shows an example of a structure of the rotation speed output control part shown in FIG. FIG. 22 is a timing chart showing the operation of the rotation state detection device shown in FIG. 21, and is a timing chart of signals at respective parts when the first sensor 21 or the second sensor becomes abnormal when the rotating body is rotating forward. is there. It is a figure which shows an example of the internal structure of the rotation speed output control part with which the rotation state detection apparatus in Embodiment 6 of this invention is provided. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 24, and is a timing chart of each part signal when a rotary body is carrying out normal rotation normally. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 24, and is a timing chart of each part signal when a 1st sensor becomes abnormal when a rotary body is carrying out normal rotation. It is a timing chart for demonstrating operation | movement of the rotation state detection apparatus shown in FIG. 24, and is a timing chart of each part signal when a 2nd sensor becomes abnormal when a rotary body is carrying out normal rotation. It is a figure which shows an example of a structure of the conventional rotation state detection apparatus. It is a timing chart which shows operation | movement of the conventional rotation state detection apparatus shown in FIG. 28, and is a timing chart of each part signal in case the rotary body is carrying out normal rotation. It is a timing chart which shows operation | movement of the conventional rotation state detection apparatus shown in FIG. 28, and is a timing chart of each part signal in case a rotary body is carrying out reverse rotation. It is a timing chart which shows operation | movement of the conventional rotation state detection apparatus shown in FIG. 28, and is a timing chart of each part signal when a sensor becomes abnormal when the rotary body is rotating forward. It is a figure which shows another structural example of the conventional rotation state detection apparatus. FIG. 33 is a timing chart showing the operation of the conventional rotational state detection device shown in FIG. 32, and is a timing chart of signals at respective parts when the sensor is always in failure and becomes “High” when the rotating body is rotating forward. . FIG. 33 is a timing chart showing an operation of the conventional rotation state detection device shown in FIG. 32, and is a timing chart of signals at respective parts when the sensor is always “Low” when the rotating body is rotating forward and always becomes “Low”. . FIG. 33 is a timing chart showing the operation of the conventional rotation state detection device shown in FIG. 32, in which a reset occurs when a failure is detected when the sensor fails and is always “Low” when the rotating body is rotating forward. It is a timing chart of each part signal in the case. It is a timing chart which shows operation | movement of the conventional rotation state detection apparatus shown in FIG. 32, and is a timing chart of each part signal when a rotation body reverses from a normal rotation to reverse rotation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating body, 3 Rotation direction detection part, 5 Abnormality detection part, 5a Abnormality detection signal,
5b discriminating unit, 6a, 6b, 6b-1, 6c, 6d rotational speed output control unit,
6d-1 pulse superposition unit,
21 1st sensor, 22 2nd sensor, 21a, 22a Detection signal,
21e, 22e abnormality detection signal,
21r, 21f, 22r, 22f Rotation direction detection result,
31, 32, 33, 34 DFF circuit,
603 selector circuit, 611 pulse generation circuit,
701-706 Rotation state detection apparatus.

Claims (9)

A first sensor and a second sensor, which are arranged opposite to the rotating body and output a binary detection signal in the form of two rectangular waves having different phases according to the rotation of the rotating body;
A first rotation direction detection unit that detects a rotation direction of the rotating body by observing a detection signal of the second sensor at a rising edge of a detection signal from the first sensor;
A second rotation direction detection unit that detects the rotation direction of the rotating body by observing the detection signal of the second sensor when the detection signal from the first sensor falls;
A third rotation direction detection unit that detects the rotation direction of the rotating body by observing the detection signal of the first sensor when the detection signal from the second sensor rises;
A fourth rotation direction detection unit that detects the rotation direction of the rotating body by observing the detection signal of the first sensor when the detection signal from the second sensor falls;
When the discrepancy between the rotation direction detection results obtained from the first to fourth rotation direction detection units continues beyond a half cycle of the detection signal, an abnormality in at least one of the first sensor and the second sensor. An anomaly detector that outputs an anomaly detection signal by judging
A rotation state detection device comprising:   The rotational state detection device according to claim 1, wherein the abnormality detection unit includes a determination unit that determines which of the first sensor and the second sensor is abnormal.   When the detection signal of the first sensor or the second sensor is supplied and the abnormality detection signal is not supplied from the abnormality detection unit and is normal, the rotation number of the rotating body is indicated based on the detection signal. The rotation state detection device according to claim 1, further comprising a first rotation speed output control unit that outputs a rotation speed detection signal.   The rotation state detection device according to claim 3, wherein the first rotation speed output control unit stops outputting the rotation speed detection signal when the abnormality detection signal is supplied.   One of each individual abnormality detection signal indicating each abnormality of the first sensor and the second sensor is supplied from the abnormality detection unit, and the detection signal is supplied from the first sensor and the second sensor, respectively. When the individual abnormality detection signal is supplied, the second rotation number that outputs the rotation number detection signal indicating the rotation number of the rotating body based on the detection signal in the first sensor or the second sensor that is normal The rotation state detection device according to claim 1, further comprising an output control unit.   The rotation state detection device according to claim 5, wherein the second rotation speed output control unit includes an output level changing unit that changes an output level of the rotation speed detection signal when the individual abnormality detection signal is supplied. Individual abnormality detection signals indicating individual abnormalities of the first sensor and the second sensor are supplied from the abnormality detection unit, and the detection signals are supplied from the first sensor and the second sensor, respectively. A third rotation speed output control unit that outputs a rotation speed detection signal indicating the rotation speed of the rotating body based on the detection signal of the first sensor or the second sensor that is normal when an abnormality detection signal is supplied; In addition,
When the individual abnormality detection signal is supplied, the third rotation speed output control unit changes the output level of the rotation speed detection signal and notifies which of the first sensor and the second sensor is abnormal. The rotation state detection apparatus according to claim 1, further comprising an output level changing unit that performs the operation. One of each individual abnormality detection signal indicating each abnormality of the first sensor and the second sensor is supplied from the abnormality detection unit, and the detection signal is supplied from the first sensor and the second sensor, respectively. When the individual abnormality detection signal is supplied, the second rotation number that outputs the rotation number detection signal indicating the rotation number of the rotating body based on the detection signal in the first sensor or the second sensor that is normal An output control unit;
A pulse generator for generating a pulse having a frequency faster than the rotational speed of the rotating body;
Individual abnormality detection signals indicating individual abnormalities of the first sensor and the second sensor are supplied from the abnormality detection unit, and the pulses generated by the pulse generation unit are superimposed on the rotation speed detection signal and output. The rotation state detection device according to claim 1, further comprising: a pulse superimposing unit that performs.   The pulse superimposing unit switches the number of pulses to be superimposed on the rotation speed detection signal depending on whether it is normal, the first sensor is abnormal, or the second sensor is abnormal. Rotation state detection device.

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