JP6352540B2 - Detection device, rotation angle detection device, detection method, and program - Google Patents

Description

  The present invention relates to a detection device, a rotation angle detection device, a detection method, and a program.

Conventionally, magnetic rotation angle sensors and magnetic encoders have been used to detect the rotation angle of a rotating body. The magnetic rotation angle sensor and encoder have a problem that the accuracy of the sensor is deteriorated due to the influence of a disturbance magnetic field emitted from other than the detection target because the detection target is a magnetic field generated from the detection target. In such a case, for example, as in Patent Document 1, it has been known that the disturbance magnetic field is guided in a direction not applied to the sensor using a magnetic shield to prevent deterioration in accuracy of the magnetic rotation angle detection device. .
Patent Document 1 JP 2013-228371 A Patent Document 2 JP 2002-71381 A

  However, it is difficult to reduce the size of the encoder with the means for surrounding the rotating body with such a magnetic shield, and the number of parts increases, which complicates the manufacturing process. Furthermore, when a magnetic rotation angle sensor is employed as an encoder for a motor, it is difficult to take measures against a disturbance magnetic field propagating from the motor side with such a magnetic shield.

  According to a first aspect of the present invention, there is provided a detection device that detects a rotation angle of a rotating body that generates a magnetic field, the first magnetoelectric conversion unit that detects the magnetic field of the rotating body, and the magnetic field of the rotating body as a first magnetoelectric. A second magnetoelectric conversion unit that detects a phase different from that of the conversion unit, an angle calculation unit that calculates a rotation angle of the rotating body based on detection results of the first magnetoelectric conversion unit and the second magnetoelectric conversion unit, and an angle calculation unit. Based on the calculated rotation angle, the angle prediction unit that predicts the rotation angle of the rotating body, the rotation angle calculated by the angle calculation unit, and the rotation angle predicted by the angle prediction unit, the rotation angle of the rotating body is calculated. A detection device, a detection method, and a program are provided.

  According to a second aspect of the present invention, there is provided a rotation angle detection device comprising: the detection device of the first aspect; and a rotating body that generates a magnetic field that changes in a rotation cycle and supplies the magnetic field to the detection device.

(General disclosure)
(Item 1)
The detection device may detect the rotation angle of the rotating body that generates the magnetic field.
The detection apparatus may include a first magnetoelectric conversion unit that detects the magnetic field of the rotating body.
The detection device may include a second magnetoelectric conversion unit that detects the magnetic field of the rotating body at a phase different from that of the first magnetoelectric conversion unit.
The detection device may include an angle calculation unit that calculates a rotation angle of the rotating body based on detection results of the first magnetoelectric conversion unit and the second magnetoelectric conversion unit.
The detection apparatus may include an angle prediction unit that predicts the rotation angle of the rotating body based on the rotation angle calculated by the angle calculation unit.
The detection apparatus may include a determination unit that determines the rotation angle of the rotating body based on a comparison result between the rotation angle calculated by the angle calculation unit and the rotation angle predicted by the angle prediction unit.
(Item 2)
The angle prediction unit may predict the current rotation angle of the rotating body based on the calculation results calculated by the angle calculation unit up to the previous time.
(Item 3)
The determination unit determines the rotation angle predicted by the angle prediction unit according to the difference between the rotation angle calculated by the angle calculation unit and the rotation angle predicted by the angle prediction unit exceeding a predetermined threshold. The rotation angle may be determined.
(Item 4)
The angle prediction unit may predict the rotation angle of the rotating body based on a predetermined number of calculation results calculated by the angle calculation unit.
(Item 5)
The angle prediction unit may predict the rotation angle of the rotating body using an average value based on a predetermined number of calculation results calculated by the angle calculation unit.
(Item 6)
The detection device may include a storage unit.
The storage unit may store a predetermined number of setting values.
(Item 7)
The storage unit may store a preset threshold value.
(Item 8)
The angle prediction unit may predict the rotation angle of the rotating body at a predetermined cycle.
The storage unit may store a predetermined cycle as a set value.
(Item 9)
The predetermined threshold value may be an angle of 1.0 degree to 3.6 degree.
The predetermined threshold value may be an angle of 1.0 degree to 3.6 degree.
The predetermined threshold may be a digital value corresponding to the angle.
(Item 10)
The detection apparatus may include a selection unit that selects whether to use the prediction of the angle prediction unit.
When the selection unit selects not to use the prediction of the angle prediction unit, the determination unit may determine the rotation angle calculated by the angle calculation unit as the rotation angle of the rotating body.
(Item 11)
The first magnetoelectric converter may detect the magnetic field of the rotating body that changes in a sine wave shape.
(Item 12)
The second magnetoelectric conversion unit may detect a magnetic field that changes at a rotation cycle of the rotating body.
The second magnetoelectric conversion unit may detect the magnetic field of the rotating body with a phase that is 90 degrees different from that of the first magnetoelectric conversion unit.
(Item 13)
The first magnetoelectric conversion unit may include a Hall element.
The second magnetoelectric conversion unit may include a Hall element.
(Item 14)
The detection apparatus may include an output unit that outputs the rotation angle determined by the determination unit.
(Item 15)
The rotation angle detection device may include a detection device.
The rotation angle detection device may include a rotating body that generates a magnetic field that changes in a rotation cycle and supplies the magnetic field to the detection device.
It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

The structural example of the rotary body 10 which concerns on this embodiment is shown. The structural example of the detection apparatus 100 which concerns on this embodiment is shown. An example of the operation | movement flow of the detection apparatus 100 which concerns on this embodiment is shown. An example of the result of the angle calculation unit 150 according to the present embodiment calculating the rotation angle of the rotating body 10 is shown. An example of the result of the determination unit 180 according to the present embodiment determining the rotation angle of the rotating body 10 is shown. The 1st modification of the detection apparatus 100 which concerns on this embodiment is shown. The 2nd modification of the detection apparatus 100 which concerns on this embodiment is shown. An example of a hardware configuration of a computer 1900 functioning as the detection apparatus 100 according to the present embodiment is shown.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows a configuration example of a rotating body 10 according to the present embodiment. The rotating body 10 is connected to a driving device such as a motor and rotates about a rotation axis. The rotating body 10 rotates while generating a magnetic field, and applies the rotating magnetic field to a magnetic sensor that detects the magnetic field of the rotating body 10. FIG. 1 shows a first magnetoelectric conversion unit 110 and a second magnetoelectric conversion unit 120 as an example of a magnetic sensor. The first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 will be described later. The rotating body 10 includes a rotating magnet 12 and a rotating shaft 14.

  The rotating magnet 12 rotates around the rotating shaft 14. As an example, the rotary magnet 12 has a disk shape and rotates in parallel with a predetermined first plane. The rotating magnet 12 may be divided into two regions each having a semicircular cross section substantially parallel to the first plane, and is formed of a magnet in which one region is an S pole and the other region is an N pole. May be.

  Instead of this, the rotating magnet 12 may be formed such that, of the two divided areas, a part of one area is an S pole and a part of the other area is an N pole. . Instead of this, the rotary magnet 12 may be divided into a plurality of four or more regions, and at least a part of the half of the divided regions is the S pole, and the remaining half of the regions It may be formed so that at least a part of the region has an N pole.

The rotating magnet 12 rotates on a plane substantially parallel to the first plane, and ideally, for example, as shown by the following equation, a magnetic field that changes in a sine wave shape or a cosine wave shape is applied to an external magnetic sensor or the like. Apply.
(Equation 1)
H _X (θ) = cos (θ)
H _Y (θ) = sin (θ)

  The rotation shaft 14 is formed in a direction substantially perpendicular to the first plane. One end of the rotating shaft 14 is connected to the rotating magnet 12. The other end of the rotating shaft 14 is connected to a driving device such as a motor. That is, the drive device rotates the rotating shaft 14 and the rotating magnet 12 connected to the rotating shaft. In the present embodiment, an example will be described in which the drive device rotates the rotating magnet 12 in a predetermined rotation direction at a predetermined substantially constant rotation speed.

  The first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 detect a rotating magnetic field generated by the rotating body 10. The 1st magnetoelectric conversion part 110 and the 2nd magnetoelectric conversion part 120 are arrange | positioned so that the circumference | surroundings of the rotating magnet 12 may be crossed by planar view in a 1st plane, for example. That is, each of the first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 is disposed so as to intersect with a cylinder extending in parallel to the rotation shaft 14 from the circumference of the rotary magnet 12. The 1st magnetoelectric conversion part 110 and the 2nd magnetoelectric conversion part 120 may be arrange | positioned on the surface on the opposite side to the drive device side of the rotating magnet 12, and may be arrange | positioned on the surface by the side of a drive device instead of this. . Further, the first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 may be arranged so as to sandwich the rotating magnet 12.

  FIG. 1 shows an example in which the first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 are arranged near the circumference of the rotating magnet 12, more precisely, just below the circumference. For example, a magnetic field that varies in a sine wave shape is applied to the first magnetoelectric conversion unit 110, and a magnetic field that varies in a cosine wave shape is applied to the second magnetoelectric conversion unit 120. That is, FIG. 1 shows an example in which the first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 are arranged such that a sine wave or cosine wave magnetic field having a phase difference of 90 ° is applied.

  FIG. 2 shows a configuration example of the detection apparatus 100 according to the present embodiment. The detection apparatus 100 detects the rotation angle of the rotating body 10 that generates a magnetic field. The detection apparatus 100 detects the rotating magnetic field generated by the rotating body 10 as shown in FIG. 1 and detects the rotation angle of the rotating body 10. The detection apparatus 100 includes a first magnetoelectric conversion unit 110, a second magnetoelectric conversion unit 120, a first amplification unit 130, a second amplification unit 132, an AD conversion unit 140, an AD conversion unit 142, and a storage unit 146. An angle calculation unit 150, an angle prediction unit 160, a comparison unit 170, a determination unit 180, and an angle output unit 190.

  The 1st magnetoelectric conversion part 110 detects the magnetic field of the rotary body 10 which changes with a rotation period. The first magnetoelectric conversion unit 110 outputs an electrical signal substantially proportional to the applied magnetic field as a detection signal for the magnetic field. The first magnetoelectric converter 110 is applied with a magnetic field that periodically changes according to the rotating magnetic field of the rotating body 10, and outputs a periodic detection signal that changes with the period of the rotating magnetic field. The 1st magnetoelectric conversion part 110 may detect the magnetic field of the rotary body 10 which changes to a sine wave form. Here, the 1st magnetoelectric conversion part 110 of this embodiment demonstrates the example which applies a sinusoidal magnetic field and outputs a sinusoidal detection signal.

  The first magnetoelectric conversion unit 110 may be substantially the same magnetic sensor as the first magnetoelectric conversion unit 110 described in FIG. The 1st magnetoelectric conversion part 110 has a Hall element which detects a magnetic field as an example. In addition, the magnetic sensor which the 1st magnetoelectric conversion part 110 has is not limited to a Hall element, if it is a magnetic sensor which can detect the magnetic field which changes periodically. The first magnetoelectric conversion unit 110 supplies the detection signal to the first amplification unit 130.

  The second magnetoelectric conversion unit 120 detects the magnetic field of the rotating body 10 that changes in the rotation cycle with a phase different from that of the first magnetoelectric conversion unit 110. The second magnetoelectric conversion unit 120 outputs an electric signal substantially proportional to the applied magnetic field as a detection signal of the magnetic field. The second magnetoelectric conversion unit 120 is applied with a magnetic field that periodically changes according to the rotating magnetic field of the rotating body 10, and outputs a periodic detection signal that changes with the period of the rotating magnetic field. Here, the phase detected by the second magnetoelectric conversion unit 120 has a predetermined phase difference compared to the phase detected by the first magnetoelectric conversion unit 110. For example, the second magnetoelectric conversion unit 120 detects a magnetic field that changes with the rotation period of the rotating body 10 with a phase that is approximately 90 degrees different from that of the first magnetoelectric conversion unit 110. In addition, the 2nd magnetoelectric conversion part 120 of this embodiment demonstrates the example which outputs the cosine-wave-like detection signal by applying the cosine-wave-like magnetic field from which a phase differs substantially 90 degree | times.

  The 2nd magnetoelectric conversion part 120 may be a magnetic sensor substantially the same as the 2nd magnetoelectric conversion part 120 demonstrated in FIG. The 2nd magnetoelectric conversion part 120 has a Hall element which detects a magnetic field as an example. In addition, the magnetic sensor which the 2nd magnetoelectric conversion part 120 has is not limited to a Hall element, if it is a magnetic sensor which can detect the magnetic field which changes periodically applied. The second magnetoelectric conversion unit 120 supplies the detection signal to the second amplification unit 132.

  The first amplification unit 130 receives the detection signal of the first magnetoelectric conversion unit 110 and amplifies the detection signal. The first amplification unit 130 may be connected to the first magnetoelectric conversion unit 110 and may amplify the received detection signal with a predetermined amplification factor. The first amplification unit 130 supplies the amplified detection signal to the AD conversion unit 140.

  The second amplification unit 132 receives the detection signal of the second magnetoelectric conversion unit 120 and amplifies the detection signal. The second amplification unit 132 may be connected to the second magnetoelectric conversion unit 120, and may amplify the received detection signal with a predetermined amplification factor. The second amplification unit 132 supplies the amplified detection signal to the AD conversion unit 142.

  The AD conversion unit 140 receives the amplified detection signal and converts the detection signal into a digital value. The AD conversion unit 140 may be connected to the first amplifying unit 130 and may convert the received detection signal into a digital value in a predetermined clock cycle or the like. The AD conversion unit 140 supplies the converted digital signal to the angle calculation unit 150.

  The AD conversion unit 142 receives the amplified detection signal and converts the detection signal into a digital value. The AD conversion unit 142 may be connected to the second amplification unit 132, and may convert the received detection signal into a digital value at a predetermined clock cycle or the like. The AD conversion unit 142 supplies the converted digital signal to the angle calculation unit 150.

  The storage unit 146 stores setting values and the like of the detection device 100. The storage unit 146 may store intermediate data, calculation results, and the like in the process in which the detection device 100 detects the rotation angle of the rotating body 10. Further, the storage unit 146 may supply the stored setting value, data, and the like to the request source in response to a request from each unit in the detection apparatus 100.

  The angle calculation unit 150 calculates the rotation angle of the rotating body 10 based on the detection results of the first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120. The angle calculation unit 150 may be connected to the AD conversion unit 140 and the AD conversion unit 142, respectively, and may calculate the rotation angle based on the received detection signal. The angle calculation unit 150 indicates that the received detection signals are a sine wave signal and a cosine wave signal, and that the phase of the two signals is shifted by a predetermined phase difference (approximately 90 degrees in this example). Since it is known, the direction of the magnetic field applied to the first magnetoelectric conversion unit 110 and the second magnetoelectric conversion unit 120 on the first plane (that is, the rotation angle of the rotating body 10) can be calculated. The angle calculation unit 150 supplies the calculation result to the comparison unit 170.

  The angle prediction unit 160 predicts the rotation angle of the rotating body 10 based on the rotation angle calculated by the angle calculation unit 150. The angle prediction unit 160 may predict the rotation angle of the rotating body 10 using one or more rotation angles determined by the detection device 100 based on the calculation result of the angle calculation unit 150. The angle prediction unit 160 may sequentially receive the output values of the detection device 100 and accumulate one or a plurality of rotation angles. When the storage unit 146 stores the output of the detection device 100, the angle prediction unit 160 may be connected to the storage unit 146, and acquires one or more rotation angles determined by the detection device 100. Also good.

  The angle prediction unit 160 predicts the current rotation angle of the rotating body 10 based on the calculation results calculated by the angle calculation unit 150 until the previous time. For example, the angle predicting unit 160 calculates the rotational speed of the rotating body 10 according to the accumulated output value of the past detection device 100, and according to the rotational speed and the previous rotation angle determined by the detection device 100. Thus, the current rotation angle of the rotating body 10 is predicted. As an example, the angle prediction unit 160 may calculate the rotation speed on the assumption that the rotating body 10 is rotating at a constant speed.

  The angle prediction unit 160 may predict the rotation angle of the rotating body 10 based on a predetermined number of calculation results calculated by the angle calculation unit 150. For example, the angle prediction unit 160 predicts the rotational speed of the rotating body 10 based on a predetermined number of output values of the past detection devices 100 accumulated. For example, the angle prediction unit 160 predicts the rotation angle of the rotating body 10 using an average value based on a predetermined number of calculation results calculated by the angle calculation unit 150. Note that the storage unit 146 may store the predetermined number of setting values, and in this case, the angle prediction unit 160 may acquire the predetermined number from the storage unit 146. The angle prediction unit 160 predicts the current rotation angle of the rotating body 10 according to the predicted rotation speed and the previous output of the detection device 100, and supplies the prediction result to the comparison unit 170.

  The comparison unit 170 compares the calculation result of the angle calculation unit 150 with the prediction result of the angle prediction unit 160. That is, the comparison unit 170 compares the current calculation result of the angle calculation unit 150 with the prediction results of the angle prediction unit 160 until the previous time. The comparison unit 170 may be connected to the angle calculation unit 150 and the angle prediction unit 160, and may determine whether or not the difference between the received calculation result and the prediction result exceeds a predetermined threshold.

  Note that the storage unit 146 may store the preset value of the predetermined threshold value, and in this case, the comparison unit 170 may acquire the predetermined threshold value from the storage unit 146. The predetermined threshold value is, for example, a digital value corresponding to an angle of 1.0 ° to 3.6 °, or an angle of 1.0 ° to 3.6 °. The comparison unit 170 supplies the comparison result to the determination unit 180.

  The determination unit 180 determines the rotation angle of the rotating body 10 based on the comparison result between the rotation angle calculated by the angle calculation unit 150 and the rotation angle predicted by the angle prediction unit 160. The determination unit 180 may be connected to the comparison unit 170, and determines the rotation angle of the rotating body 10 according to the received comparison result of the comparison unit 170. The determination unit 180 determines the rotation predicted by the angle prediction unit 160 when the difference between the rotation angle calculated by the angle calculation unit 150 and the rotation angle predicted by the angle prediction unit 160 exceeds a predetermined threshold. The angle may be determined as the rotation angle of the rotating body 10.

  When the difference between the rotation angle calculated by the angle calculation unit 150 and the rotation angle predicted by the angle prediction unit 160 is less than a predetermined threshold, the determination unit 180 determines the rotation angle calculated by the angle calculation unit 150 as a rotating body. It may be determined that the rotation angle is 10. The determination unit 180 supplies the determined rotation angle to the angle output unit 190. Further, the determination unit 180 supplies the determined rotation angle to the angle prediction unit 160 as an output value of the detection device 100 used for the next prediction.

  The angle output unit 190 supplies the determined rotation angle to the outside of the detection device 100. The angle output unit 190 may be connected to the determination unit 180 and supplies the received rotation angle to the outside as an output of the detection device 100. The angle output unit 190 may be an interface with the outside. In this case, the angle output unit 190 may convert the format or the like of output data into the format or the like of input data such as an external device to be supplied.

  According to the detection apparatus 100 according to the above-described embodiment, even when a disturbance magnetic field other than the detection target (that is, the rotating body 10) is generated, the influence of the disturbance magnetic field is reduced to prevent deterioration in accuracy of the sensor. Can do. The operation of such a detection apparatus 100 will be described with reference to FIG.

  FIG. 3 shows an example of an operation flow of the detection apparatus 100 according to the present embodiment. First, the rotating body 10 rotates at a predetermined rotation speed to generate a rotating magnetic field (S310). In the present embodiment, an example in which the rotating body 10 rotates at a rotational speed of 3000 [rpm] will be described.

  The first magnetoelectric conversion unit and the second magnetoelectric conversion unit detect the rotating magnetic field generated by the rotating body 10 (S320). The AD conversion unit 140 converts the detection signal of the first magnetoelectric conversion unit 110 amplified by the first amplification unit 130 into a digital signal, and the AD conversion unit 142 converts the second magnetoelectric conversion unit 120 amplified by the second amplification unit 132. This detection signal is converted into a digital signal.

  Next, the angle calculation unit 150 receives the digital signals converted by the AD conversion unit 140 and the AD conversion unit 142, respectively, and calculates the rotation angle of the rotating body 10 (S330). Here, the angle calculator 150 may calculate the rotation angle of the rotating body 10 at predetermined time intervals. The angle calculation unit 150 may calculate the rotation angle according to a clock signal having a predetermined period. In the present embodiment, an example in which the angle calculation unit 150 calculates the rotation angle approximately every 0.0556 ms will be described.

  FIG. 4 shows an example of a result of calculating the rotation angle of the rotating body 10 by the angle calculation unit 150 according to the present embodiment. In FIG. 4, the horizontal axis represents time (unit: “ms”), and the vertical axis represents rotation angle (unit: “°”). FIG. 4 shows an example in which 14 points are plotted among the results of the angle calculation unit 150 calculating the rotation angle of the rotating body 10 rotating at 3000 rpm in a time series approximately every 0.0556 ms. FIG. 4 shows an example in which an error is generated in the angle calculation result due to the influence of the disturbance magnetic field in the eleventh data (data having a time of approximately 2.5 ms).

  Similarly to the angle calculation unit 150, the angle prediction unit 160 may predict the rotation angle of the rotating body 10 every predetermined time (that is, at a predetermined cycle) (S340). That is, the angle prediction unit 160 may be supplied with a clock signal having a predetermined period supplied to the angle calculation unit 150 and may calculate a rotation angle in accordance with the clock signal. In FIG. 3, the angle prediction of the angle prediction unit 160 is a flow executed after the calculation of the rotation angle of the angle calculation unit 150. Instead, the angle prediction of the angle prediction unit 160 is the angle calculation. It may be executed at substantially the same timing as the calculation of the rotation angle of the unit 150 (that is, at substantially the same clock phase). Instead of this, the angle prediction of the angle prediction unit 160 may be executed before the calculation of the rotation angle of the angle calculation unit 150.

  Further, the predetermined period may be stored as a set value in the storage unit 146. In this case, the clock signal generation unit inside the detection apparatus 100 reads the setting and calculates the angle of the corresponding clock signal. May be supplied to the unit 150, the angle prediction unit 160, and the like.

  Here, the angle prediction unit 160 first predicts the rotation angle of the rotating body 10 based on a predetermined number of calculation results. In the present embodiment, an example in which the angle prediction unit 160 predicts the rotation angle of the rotating body 10 using the ten rotation angles previously determined by the detection apparatus 100 based on the calculation result of the angle calculation unit 150 will be described. To do. In this case, each time the detection apparatus 100 determines the rotation angle, the angle prediction unit 160 may discard the information on the oldest rotation angle and update the ten rotation angles. That is, the angle prediction unit 160 may update 10 rotation angles approximately every 0.0556 ms, and predict the rotation angle using the updated rotation angles.

  That is, the angle predicting unit 160 grasps the degree of change of the rotation angle from the most recently determined values of the ten rotation angles, and predicts the next rotation angle according to the degree of change. The angle prediction unit 160 may calculate the degree of change in the rotation angle as an average value of the differences of the 10 pieces of accumulated angular position data. The average value of the differences corresponds to the rotation speed of the rotating body 10. In addition, the angle prediction unit 160 may calculate an average rotation speed obtained by dividing the average value of the difference by the clock period.

  Next, the comparison unit 170 compares the calculation result of the angle calculation unit 150 with the prediction result of the angle prediction unit 160 (S350). The comparison part 170 of this embodiment demonstrates the example which determines whether the absolute value of the difference of a calculation result and a prediction result exceeds a threshold value. Note that the comparison unit 170 will describe an example in which the threshold value is set to 1.5 ° (that is, the threshold value is set in the storage unit 146). For example, since the first data shown in FIG. 4 is hardly affected by the disturbance magnetic field, the comparison result of the comparison unit 170 is less than the threshold value.

  Next, the determination unit 180 determines one of the calculation result of the angle calculation unit 150 and the prediction result of the angle prediction unit 160 as the rotation angle of the rotating body 10 according to the comparison result of the comparison unit 170 (S360). . For example, the determination unit 180 determines the calculation result of the angle calculation unit 150 as the rotation angle of the rotating body 10 in response to the first data shown in FIG. The determination unit 180 supplies the determined rotation angle to the angle output unit 190 and supplies the angle prediction unit 160 with information on the rotation angle as data used for the next prediction. In response to receiving the rotation angle information, the angle prediction unit 160 may discard the oldest rotation angle information and update the ten rotation angles.

  The detection apparatus 100 repeats the operations from the detection of the rotating magnetic field of the rotating body 10 (S320) to the determination of the rotating angle of the rotating body 10 (S360) until the end of the detecting operation (S370: No), and the rotation angles in time series. I will decide. For example, the first magnetoelectric conversion unit and the second magnetoelectric conversion unit detect the rotating magnetic field at the first time, and based on the detection result, the angle calculation unit 150 calculates the calculation result of the first angle calculation unit 150 shown in FIG. , And the determination unit 180 determines the calculation result as the first rotation angle of the rotating body 10. Then, the first magnetoelectric conversion unit and the second magnetoelectric conversion unit detect the rotating magnetic field at the next time, and the angle calculation unit 150 outputs the calculation result of the second angle calculation unit 150 shown in FIG. Based on the result, the determination unit 180 determines the second rotation angle of the rotating body 10.

The detection apparatus 100 repeats the above operation to sequentially determine the rotation angle. For example, when outputting a predetermined number of data, the detection apparatus 100 ends the repetition (S370: Yes). Moreover, the detection apparatus 100 may end the repetition when the end of the detection operation is instructed. The end of the detection operation may be input from an external device or the like, or may be input by the user of the detection device 100. Table 1 shows an example of data calculated by each unit of the detection apparatus 100 with respect to the calculation result of the angle calculation unit 150 in FIG.

  Table 1 shows data numbers in the first column, and the detection time of the rotating magnetic field in the second column. That is, the detection time in the second column corresponds to the data value on the horizontal axis of each data in FIG. The third column shows the angle calculation results calculated by the angle calculation unit 150 according to the detection results of the rotating magnetic fields detected at the respective detection times. That is, the angle calculation result in the third column corresponds to the data value on the vertical axis of each data in FIG. The determination result of the determination unit 180 is shown in the fourth column, and the determination result of the previous determination unit 180 is shown in the fifth column (the value of the row corresponding to the data number one less than the current data number in the fourth column). And the current determination result of the determination unit 180 (the value of the row corresponding to the current data number in the fourth column). Note that the difference in the fifth column corresponds to the rotation speed per unit time (0.0556 s).

  The sixth column shows the average rotation speed (that is, the average value of the latest ten rotation speeds in the fifth column), the seventh column shows the prediction result of the angle prediction unit 160, and the eighth column shows the angle prediction unit. The difference between the 160 prediction results (seventh column) and the angle calculation results (third column) is shown. The rotating body 10 rotates at a substantially constant rotational speed of 3000 rpm, but each data includes a certain degree of variation due to weak noise, sensor-specific angle error, and the like.

  The absolute value of the difference (eighth column) between the prediction result of the angle prediction unit 160 and the angle calculation result in the rows of data numbers 0 to 9 in Table 1 is a threshold value (1.5 °), respectively. Is less than Therefore, the determination unit 180 determines the angle calculation result (third column) of the angle calculation unit 150 as the rotation angle determination result (fourth column).

  From the row of data number 10, the prediction result (seventh column) of the angle prediction unit 160 is 44.95 °. The value is an average value of the difference (fifth column) between the current and previous output of the determining unit 180 from the data numbers 0 to 9 (that is, the value in the sixth column of the data number 10). The result is calculated by adding 99 ° to 43.97 °, which is the output (fourth column) of the determination unit 180 with the data number 9 (significant digits are the second decimal place).

  The difference (eighth column) between 44.95 ° that is the prediction result (seventh column) of the angle prediction unit 160 calculated in this way and 52.34 ° that is the angle calculation result (third column) is −7.38 °, and the absolute value exceeds the threshold value. Therefore, the determination unit 180 sets the prediction result (44.95 °) of the angle prediction unit 160 as the determination result (fourth column).

  That is, the detection apparatus 100 compares the current predicted value predicted from the average value of the past rotation speeds with the current angle calculation result, and the current angle calculation result according to the difference exceeding the threshold value. Is determined to be a result of the influence of the disturbance magnetic field, and the current predicted value is set as the determination value of the rotation angle. As a result, a more probable value can be adopted by excluding the value of the angle calculation result affected by the disturbance magnetic field that occurs suddenly. Further, the determination unit 180 supplies the determined value of the current rotation angle to the angle prediction unit 160, and the angle prediction unit 160 updates the received determination value as the latest determination value. Therefore, the angle predicting unit 160 can execute the prediction of the next rotation angle without using the angle calculation result affected by the disturbance magnetic field, and predict a more probable value for the prediction result after the next time. Can do.

  FIG. 5 shows the results calculated by the detection apparatus 100 according to the present embodiment as shown in Table 1. FIG. 5 shows an example of a result of the determination unit 180 according to the present embodiment determining the rotation angle of the rotating body 10. In FIG. 5, as in FIG. 4, the horizontal axis indicates time (unit: “ms”), and the vertical axis indicates rotation angle (unit: “°”). Also, FIG. 5 differs from FIG. 4 in that the abrupt data fluctuation due to the disturbance magnetic field is eliminated in the eleventh data (data having a time of approximately 2.5 ms), and the influence of the disturbance magnetic field is reduced. . That is, with respect to the calculation result of the angle calculation unit 150 illustrated in FIG. 4, the determination unit 180 can select and employ the prediction result of the angle prediction unit 160 so as to reduce the influence of the disturbance magnetic field.

  FIG. 6 shows a first modification of the detection apparatus 100 according to this embodiment. In the detection device 100 according to the first modification, the same reference numerals are given to the substantially same operations as those of the detection device 100 according to the present embodiment shown in FIG. 2, and the description thereof is omitted. The detection device 100 according to the first modification includes a selection unit 210.

  The selection unit 210 selects whether or not to use the prediction of the angle prediction unit 160. The selection unit 210 selects not to use the prediction of the angle prediction unit 160, for example, in the case of idling of the apparatus, trial operation, a state in which there is almost no influence of the external magnetic field, and the case of measuring the influence of the external magnetic field. The selection unit 210 may execute the selection based on the setting value stored in the storage unit 146. Instead, the selection unit 210 may execute the selection by an external device, an application, a user input, or the like.

  The selection unit 210 may be connected between the angle prediction unit 160 and the comparison unit 170. In this case, the selection unit 210 supplies the prediction result received from the angle prediction unit 160 to the comparison unit 170 when the prediction of the angle prediction unit 160 is used, and the angle prediction unit 160 when the prediction of the angle prediction unit 160 is not used. The prediction result received from is not supplied to the comparison unit 170. Instead, the selection unit 210 may be connected to the angle prediction unit 160. In this case, when the prediction of the angle prediction unit 160 is used, the selection unit 210 instructs the angle prediction unit 160 to execute a prediction operation. When the prediction of the angle prediction unit 160 is not used, the selection unit 210 performs prediction to the angle prediction unit 160. Instruct to stop operation. Note that the selection unit 210 may instruct the comparison unit 170 to stop the comparison operation.

  When the comparison unit 170 receives the calculation result of the angle calculation unit 150 from the angle calculation unit 150 or the selection unit 210, the comparison unit 170 performs the above-described comparison operation. Further, the comparison unit 170 determines the calculation result of the angle calculation unit 150 when the calculation result of the angle calculation unit 150 is not received from the angle calculation unit 150 or the selection unit 210 or when the comparison operation is instructed to stop. The determination unit 180 determines the rotation angle of the rotating body 10 as a result calculated by the angle calculation unit 150. As a result, the detection apparatus 100 can switch and execute an operation for reducing the influence of the external magnetic field.

  As described above, the detection apparatus 100 according to the present embodiment can reduce the influence of the disturbance magnetic field by calculation in the apparatus without using a magnetic shield or the like. Therefore, the detection apparatus 100 according to the present embodiment can reduce the size of the magnetic rotation angle sensor or encoder and simplify the manufacturing process. Therefore, even in an environment where the generation of a disturbance magnetic field is remarkable and the space where the sensor is arranged is limited, a rotation detection device and position detection having functions such as low noise, low jitter, and accurate duty output An apparatus can be realized.

  FIG. 7 shows a second modification of the detection apparatus 100 according to this embodiment. In the detection device 100 of the second modification, the same reference numerals are given to the same components as those of the detection device 100 according to the present embodiment shown in FIG. In the detection device 100 of the second modification, the angle calculation unit 150 supplies the calculation result to the angle prediction unit 160. That is, the angle predicting unit 160 of the second modified example receives and accumulates the calculation result of the rotation angle of the rotating body 10 supplied from the angle calculating unit 150, and based on the calculation results calculated up to the previous time, Predict the current rotation angle. The angle prediction unit 160 may include a storage circuit that accumulates calculation results therein. Alternatively, the angle prediction unit 160 may be connected to the storage unit 146 and accumulate the received calculation results in the storage unit 146.

  Although the detection apparatus 100 according to the present embodiment has been described as an example in which the calculation is performed approximately every 0.0556 ms, the present invention is not limited to the time interval, and depending on the system, application, components used, etc. May be selected. Moreover, although the comparison part 170 which concerns on this embodiment demonstrated the example which sets a threshold value to 1.5 degrees, it is not limited to the said threshold value, The environment where the rotary body 10 is arrange | positioned, the intensity | strength of a disturbance magnetic field, It may be selected according to the application or the like. Moreover, although the angle prediction part 160 which concerns on this embodiment demonstrated the example which estimates a rotation angle using the average value of the past 10 rotation speed, the past data number to be used is not limited to this. Instead, it may be selected according to the system, application, internal error of the detection apparatus 100, and the like.

  Note that the angle calculation by the angle calculation unit 150 shown in FIG. 3 may use a tangent / inverse tangent calculation, or alternatively, a known calculation method may be used as the CORDIC algorithm. Alternatively, a type 2 servo system used for R / D conversion or the like, which is known as an angle calculation method of a resolver that is one of rotation angle sensors, may be used. In this case, the resolver is provided in place of the first magnetoelectric converter 110, the second magnetoelectric converter 120, the first amplifier 130, the second amplifier 132, the AD converter 140, the AD converter 142, and the angle calculator 150. The rotation angle of the rotating body 10 may be calculated and supplied to the comparison unit 170.

  In addition, the first magnetoelectric conversion unit and the second magnetoelectric conversion unit according to the present embodiment are arranged so as to overlap the circumference of the rotating body 10 in plan view so that a magnetic field that varies in a sine wave shape and a cosine wave shape is applied. An example to be described. Instead, the first magnetoelectric conversion unit and the second magnetoelectric conversion unit may be in a known arrangement as a magnetic field concentrator as described in Patent Document 2.

  Moreover, the rotating body 10 which concerns on this embodiment demonstrated the example rotated at a predetermined substantially constant rotational speed in the predetermined rotation direction. Instead of this, the rotating body 10 may rotate at a variable speed. In this case, the angle prediction unit 160 may predict the rotation angle after predicting the speed of the rotating body 10 based on the change in the past rotation speed.

  In addition, the detection apparatus 100 which concerns on this embodiment was arrange | positioned in the vicinity of the rotary body 10, and demonstrated the example which detects the rotation angle of the rotary body 10, as shown in FIG. In addition to this, the detection device 100 may be formed integrally with the rotating body 10 that generates a magnetic field that changes in a rotation cycle and supplies the magnetic field to the detection device 100. In this case, the rotating body 10 and the detection device 100 may function as a rotation angle detection device.

  FIG. 8 shows an example of a hardware configuration of a computer 1900 that functions as the detection apparatus 100 according to the present embodiment. A computer 1900 according to this embodiment is connected to a CPU peripheral unit having a CPU 2000, a RAM 2020, a graphic controller 2075, and a display device 2080 that are connected to each other by a host controller 2082, and to the host controller 2082 by an input / output controller 2084. An input / output unit having a communication interface 2030, a hard disk drive 2040, and a DVD drive 2060; a legacy input / output unit having a ROM 2010, a flexible disk drive 2050, and an input / output chip 2070 connected to the input / output controller 2084; Is provided.

  The host controller 2082 connects the RAM 2020 to the CPU 2000 and the graphic controller 2075 that access the RAM 2020 at a high transfer rate. The CPU 2000 operates based on programs stored in the ROM 2010 and the RAM 2020 and controls each unit. The graphic controller 2075 acquires image data generated by the CPU 2000 or the like on a frame buffer provided in the RAM 2020 and displays it on the display device 2080. Instead of this, the graphic controller 2075 may include a frame buffer for storing image data generated by the CPU 2000 or the like.

  The input / output controller 2084 connects the host controller 2082 to the communication interface 2030, the hard disk drive 2040, and the DVD drive 2060, which are relatively high-speed input / output devices. The communication interface 2030 communicates with other devices via a network. The hard disk drive 2040 stores programs and data used by the CPU 2000 in the computer 1900. The DVD drive 2060 reads a program or data from the DVD-ROM 2095 and provides it to the hard disk drive 2040 via the RAM 2020.

  The input / output controller 2084 is connected to the ROM 2010, the flexible disk drive 2050, and the relatively low-speed input / output device of the input / output chip 2070. The ROM 2010 stores a boot program that the computer 1900 executes at startup and / or a program that depends on the hardware of the computer 1900. The flexible disk drive 2050 reads a program or data from the flexible disk 2090 and provides it to the hard disk drive 2040 via the RAM 2020. The input / output chip 2070 connects the flexible disk drive 2050 to the input / output controller 2084 and inputs / outputs various input / output devices via, for example, a parallel port, a serial port, a keyboard port, a mouse port, and the like. Connect to controller 2084.

  A program provided to the hard disk drive 2040 via the RAM 2020 is stored in a recording medium such as the flexible disk 2090, the DVD-ROM 2095, or an IC card and provided by the user. The program is read from the recording medium, installed in the hard disk drive 2040 in the computer 1900 via the RAM 2020, and executed by the CPU 2000.

  The program is installed in the computer 1900, and causes the computer 1900 to function as the storage unit 146, the angle calculation unit 150, the angle prediction unit 160, the comparison unit 170, the determination unit 180, the angle output unit 190, and the selection unit 210.

  The information processing described in the program is read into the computer 1900, whereby the storage unit 146, the angle calculation unit 150, and the angle prediction unit 160 are specific means in which the software and the various hardware resources described above cooperate. , Function as a comparison unit 170, a determination unit 180, an angle output unit 190, and a selection unit 210. And the specific detection apparatus 100 according to the use purpose is constructed | assembled by implement | achieving the calculation or process of the information according to the use purpose of the computer 1900 in this embodiment by this concrete means.

  As an example, when communication is performed between the computer 1900 and an external device or the like, the CPU 2000 executes a communication program loaded on the RAM 2020 and executes a communication interface based on the processing content described in the communication program. A communication process is instructed to 2030. Under the control of the CPU 2000, the communication interface 2030 reads transmission data stored in a transmission buffer area or the like provided on a storage device such as the RAM 2020, the hard disk drive 2040, the flexible disk 2090, or the DVD-ROM 2095, and sends it to the network. The reception data transmitted or received from the network is written into a reception buffer area or the like provided on the storage device. As described above, the communication interface 2030 may transfer transmission / reception data to / from the storage device by the DMA (Direct Memory Access) method. Instead, the CPU 2000 transfers the storage device or the communication interface 2030 as the transfer source. The transmission / reception data may be transferred by reading the data from the data and writing the data to the communication interface 2030 or the storage device of the transfer destination.

  In addition, the CPU 2000 includes all or necessary portions of files or databases stored in an external storage device such as the hard disk drive 2040, DVD drive 2060 (DVD-ROM 2095), and flexible disk drive 2050 (flexible disk 2090). Are read into the RAM 2020 by DMA transfer or the like, and various processes are performed on the data on the RAM 2020. Then, CPU 2000 writes the processed data back to the external storage device by DMA transfer or the like. In such processing, since the RAM 2020 can be regarded as temporarily holding the contents of the external storage device, in the present embodiment, the RAM 2020 and the external storage device are collectively referred to as a memory, a storage unit, or a storage device. Various types of information such as various programs, data, tables, and databases in the present embodiment are stored on such a storage device and are subjected to information processing. Note that the CPU 2000 can also store a part of the RAM 2020 in the cache memory and perform reading and writing on the cache memory. Even in such a form, the cache memory bears a part of the function of the RAM 2020. Therefore, in the present embodiment, the cache memory is also included in the RAM 2020, the memory, and / or the storage device unless otherwise indicated. To do.

  In addition, the CPU 2000 performs various operations, such as various operations, information processing, condition determination, information search / replacement, etc., described in the present embodiment, specified for the data read from the RAM 2020 by the instruction sequence of the program. Is written back to the RAM 2020. For example, when performing the condition determination, the CPU 2000 determines whether the various variables shown in the present embodiment satisfy the conditions such as large, small, above, below, equal, etc., compared to other variables or constants. When the condition is satisfied (or not satisfied), the program branches to a different instruction sequence or calls a subroutine.

  Further, the CPU 2000 can search for information stored in a file or database in the storage device. For example, in the case where a plurality of entries in which the attribute value of the second attribute is associated with the attribute value of the first attribute are stored in the storage device, the CPU 2000 displays the plurality of entries stored in the storage device. The entry that matches the condition in which the attribute value of the first attribute is specified is retrieved, and the attribute value of the second attribute that is stored in the entry is read, thereby associating with the first attribute that satisfies the predetermined condition The attribute value of the specified second attribute can be obtained.

  The program or module shown above may be stored in an external recording medium. As a recording medium, in addition to the flexible disk 2090 and the DVD-ROM 2095, an optical recording medium such as a DVD, Blu-ray (registered trademark), or a CD, a magneto-optical recording medium such as an MO, a tape medium, a semiconductor such as an IC card, etc. A memory or the like can be used. Further, a storage device such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium, and the program may be provided to the computer 1900 via the network.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The execution order of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior”. It should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. is not.

DESCRIPTION OF SYMBOLS 10 Rotating body, 12 Rotating magnet, 14 Rotating shaft, 100 Detection apparatus, 110 1st magnetoelectric conversion part, 120 2nd magnetoelectric conversion part, 130 1st amplification part, 132 2nd amplification part, 140 AD conversion part, 142 AD conversion Unit, 146 storage unit, 150 angle calculation unit, 160 angle prediction unit, 170 comparison unit, 180 determination unit, 190 angle output unit, 210 selection unit, 1900 computer, 2000 CPU, 2010 ROM, 2020 RAM, 2030 communication interface, 2040 Hard disk drive, 2050 flexible disk drive, 2060 DVD drive, 2070 input / output chip, 2075 graphic controller, 2080 display device, 2082 host controller, 2084 input / output controller, 2090 flexible Bull disk, 2095 DVD-ROM

Claims (17)

A detection device that detects a rotation angle of a rotating body that generates a magnetic field,
A first magnetoelectric converter for detecting the magnetic field of the rotating body;
A second magnetoelectric converter that detects the magnetic field of the rotating body in a phase different from that of the first magnetoelectric converter;
An angle calculation unit for calculating a rotation angle of the rotating body based on detection results of the first magnetoelectric conversion unit and the second magnetoelectric conversion unit;
An angle prediction unit that predicts the rotation angle of the rotating body based on the rotation angle calculated by the angle calculation unit;
A selection unit for selecting whether to use the prediction of the angle prediction unit;
A determination unit that determines the rotation angle of the rotating body based on a comparison result between the rotation angle calculated by the angle calculation unit and the rotation angle predicted by the angle prediction unit;
Equipped with a,
The determination unit, when the selection unit selects not using the prediction of the angle prediction unit, that determine the rotation angle of the angle calculation section is calculating the rotation angle of the rotating body detecting device.   The detection device according to claim 1, wherein the angle prediction unit predicts a current rotation angle of the rotating body based on calculation results calculated by the angle calculation unit up to the previous time.   The determination unit is configured to perform rotation predicted by the angle prediction unit in response to a difference between a rotation angle calculated by the angle calculation unit and a rotation angle predicted by the angle prediction unit exceeding a predetermined threshold. The detection device according to claim 1, wherein the angle is determined as a rotation angle of the rotating body.   The said angle estimation part is a detection apparatus of Claim 3 which estimates the rotation angle of the said rotary body based on the output of the said determination part.   The said angle estimation part is a detection apparatus of Claim 3 which estimates the rotation angle of the said rotary body based on the calculation result of the predetermined number which the said angle calculating part calculated.   The detection device according to claim 5, wherein the angle prediction unit predicts a rotation angle of the rotating body using an average value based on a predetermined number of calculation results calculated by the angle calculation unit.   The detection device according to claim 4, further comprising a storage unit that stores the predetermined number of setting values.   The detection device according to claim 7, wherein the storage unit stores a set value of the predetermined threshold. The angle prediction unit predicts a rotation angle of the rotating body at a predetermined cycle,
The detection apparatus according to claim 7 or 8, wherein the predetermined period is stored in the storage unit as a set value.   The predetermined threshold is a digital value corresponding to an angle of 1.0 ° to 3.6 °, or an angle of 1.0 ° to 3.6 °. The detection device according to item. Said first magnetoelectric conversion unit, the detection device according to any one of claims 1 to 10 for detecting the magnetic field of the rotating body changes sinusoidally. The detection according to any one of claims 1 to 11 , wherein the second magnetoelectric conversion unit detects the magnetic field that changes at a rotation period of the rotating body at a phase that is 90 degrees different from that of the first magnetoelectric conversion unit. apparatus. The detection device according to any one of claims 1 to 12 , wherein the first magnetoelectric conversion unit and the second magnetoelectric conversion unit include a Hall element. The detection device according to any one of claims 1 to 13 , further comprising an output unit that outputs the rotation angle determined by the determination unit. The detection device according to any one of claims 1 to 14 ,
A rotating body that generates a magnetic field that changes with a rotation period and supplies the magnetic field to the detection device;
A rotation angle detector. A detection method for detecting a rotation angle of a rotating body that generates a magnetic field,
An angle calculation step of calculating a rotation angle of the rotating body;
An angle prediction step of predicting the rotation angle of the rotating body based on the rotation angle calculated in the angle calculation step;
A selection step of selecting whether to use the rotation angle predicted in the angle prediction step;
If it is selected not to use the rotation angle predicted in the angle prediction step, determining the rotation angle calculated in the angle calculation step as the rotation angle of the rotating body;
A determination step of determining a rotation angle of the rotating body based on a comparison result of the rotation angle calculated in the angle calculation step and the rotation angle predicted in the angle prediction step;
A detection method comprising:   The program which makes a computer perform the detection method of Claim 16.

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