Control device and control method

Abstract

To provide a control device and a control method capable of reducing a circuit scale for converting mechanical angels into electrical angels and improving conversion accuracy.SOLUTION: A control device includes: a first mechanical angle detection unit for calculating a first mechanical angle from a detection signal obtained by filtering a detection signal indicating a rotation angle of a motor detected by a sensor device with a first filter; a second mechanical angle detection unit for calculating a second mechanical angle from a detection signal obtained by filtering a detection signal detected by the sensor device with a second filter having a smaller phase delay than the first filter; a phase correction unit for calculating a phase difference between the second mechanical angle and the first mechanical angle by subtracting the first mechanical angle from the second mechanical angle, calculating a phase error correction amount by multiplying the phase difference by a correction coefficient, adding the phase error correction amount to the first mechanical angle, and correcting a phase error of the first mechanical angle; and a conversion unit for converting the first mechanical angle with the phase error corrected into an electrical angle.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control device and a control method.

Background Art

[0002] A brushless motor is used as a motor for assisting an electric power steering (for example, Patent Document 1). When performing vector control on a brushless motor, the sensor signal of the motor is converted from a mechanical angle to an electrical angle. This conversion is performed using, for example, various filters and conversion maps.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, depending on the filter used, a phase delay occurs, so a circuit configuration for correcting the phase delay is required, and the circuit scale increases. Further, when the conversion is performed a plurality of times, the conversion error accumulates due to the repetition of the conversion, and the conversion accuracy deteriorates.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide a control device and a control method capable of reducing the circuit scale for converting a mechanical angle to an electrical angle and improving the conversion accuracy.

Means for Solving the Problems

[0006] A control device according to an aspect of the present invention includes: a first mechanical angle detection unit that calculates a first mechanical angle from the detection signal obtained by filtering a detection signal indicating the rotation angle of a motor detected by a sensor device with a first filter; a second mechanical angle detection unit that calculates a second mechanical angle from the detection signal obtained by filtering the detection signal detected by the sensor device with a second filter having a smaller phase delay than the first filter; a phase correction unit that subtracts the first mechanical angle from the second mechanical angle to calculate a phase difference between the second mechanical angle and the first mechanical angle, multiplies the phase difference by a correction coefficient to calculate a phase error correction amount, and adds the phase error correction amount to the first mechanical angle to correct the phase error of the first mechanical angle; and a conversion unit that converts the first mechanical angle with the corrected phase error into an electrical angle.

[0007] A control method according to an aspect of the present invention includes: a first mechanical angle detection process in which a first mechanical angle detection unit calculates a first mechanical angle from the detection signal obtained by filtering a detection signal indicating the rotation angle of a motor detected by a sensor device with a first filter; a second mechanical angle detection process in which a second mechanical angle detection unit calculates a second mechanical angle from the detection signal obtained by filtering the detection signal detected by the sensor device with a second filter having a smaller phase delay than the first filter; a phase correction process in which a phase correction unit subtracts the first mechanical angle from the second mechanical angle to calculate a phase difference between the second mechanical angle and the first mechanical angle, multiplies the phase difference by a correction coefficient to calculate a phase error correction amount, and adds the phase error correction amount to the first mechanical angle to correct the phase error of the first mechanical angle; and a conversion process in which a conversion unit converts the first mechanical angle with the corrected phase error into an electrical angle.

Advantages of the Invention

[0008] According to the present invention, it is possible to reduce the circuit scale for converting a mechanical angle into an electrical angle and improve the conversion accuracy.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] <1. Schematic Configuration of Electric Power Steering Apparatus> First, with reference to FIG. 1, the schematic configuration of the electric power steering apparatus (EPS: Electric Power Steering) according to the present embodiment will be described. FIG. 1 is a block diagram showing an example of the schematic configuration of the electric power steering apparatus according to the present embodiment. As shown in FIG. 1, the electric power steering apparatus 1 includes a steering mechanism 2, a torque sensor 3, a motor 4, an analog angle sensor 5, and a control apparatus 6.

[0012] The steering mechanism 2 is a steering device for arbitrarily changing the traveling direction of a vehicle in which the electric power steering apparatus 1 is provided. When the steering mechanism 2 is operated by a driver, a steering torque is generated. The steering mechanism 2 rotates with this steering torque.

[0013] The torque sensor 3 detects the steering torque generated by the operation of the steering mechanism 2. The torque sensor 3 outputs the detected value of the detected steering torque to the control apparatus 6.

[0014] The motor 4 is a motor for assisting the steering of the steering mechanism 2. For example, the motor 4 assists the steering force with which the steering mechanism 2 steers the front wheels of the vehicle. The motor 4 is electrically connected to the control device 6 and is driven by a drive signal from the control device 6. The motor 4 is, for example, a three-phase (U, V, W) brushless motor.

[0015] The analog angle sensor 5 is provided in the motor 4. The analog angle sensor 5 detects the rotation angle of the rotor of the motor 4. For example, the analog angle sensor 5 is a magnetic sensor that detects the rotation angle. The analog angle sensor 5 outputs an output signal corresponding to the detected rotation angle to the control device 6. For example, the analog angle sensor 5 outputs two-phase detection signals, a cosine signal (cosθ) and a sine signal (sinθ), indicating the rotation angle of the rotor of the motor 4.

[0016] The control device 6 is a device for controlling the overall operation of the electric power steering device 1. For example, the control device 6 is realized by an ECU (Engine Control Unit). The control device 6 controls the drive of the motor 4 based on the steering torque detected by the torque sensor 3. That is, the control device 6 has a function as a motor driver. In controlling the motor 4, the control device 6 controls so that the current flowing through the motor 4 becomes a target value. At this time, the control device 6 converts the angle indicated by the detection signal detected by the analog angle sensor 5 from a mechanical angle to an electrical angle, and determines the current vector based on this electrical angle.

[0017] <2. Functional Configuration of Conventional Control Device> Above, the schematic configuration of the electric power steering device 1 according to the present embodiment has been described. Subsequently, with reference to FIG. 4, a conventional control device will be described. FIG. 4 is a block diagram showing an example of the functional configuration of a conventional control device. As shown in FIG. 4, the conventional control device 100 includes an electrical angle detection unit 120 and a phase correction unit 150.

[0018] The electrical angle detection unit 120 calculates the mechanical angle from the detection signal of the analog angle sensor 5, converts the calculated mechanical angle into an electrical angle, and outputs it. As shown in FIG. 4, the electrical angle detection unit 120 includes Butterworth three-dimensional filters 121a and 121b, an angle calculation unit 122, and a conversion map 123.

[0019] The two-phase detection signal output from the analog angle sensor 5 is supplied to the Butterworth three-dimensional filters 121a and 121b. For example, a cosine signal is input to the Butterworth three-dimensional filter 121a, and a sine signal is input to the Butterworth three-dimensional filter 121b. The Butterworth three-dimensional filters 121a and 121b filter the input signals respectively. After filtering, the Butterworth three-dimensional filters 121a and 121b output the filtered detection signals to the angle calculation unit 122.

[0020] Based on the two-phase detection signals filtered by the Butterworth three-dimensional filters 121a and 121b, the angle calculation unit 122 calculates the mechanical angle corresponding to the detection signals. After the calculation, the angle calculation unit 122 outputs the calculated mechanical angle to the conversion map 123.

[0021] The conversion map 123 converts the mechanical angle input from the angle calculation unit 122 into an electrical angle and outputs it. In this conversion, the conversion map 123 corrects the input mechanical angle and then converts it into an electrical angle. The correction of the mechanical angle is performed, for example, to fill the difference between the mechanical angle calculated by the angle calculation unit 122 and the mechanical angle measured by the encoder and input from the outside.

[0022] The phase correction unit 150 corrects the phase error occurring in the electrical angle calculated by the electrical angle detection unit 120 and outputs the corrected electrical angle. The electrical angle output from the conversion map 123 of the electrical angle detection unit 120 is obtained from the detection signals filtered by the Butterworth three-dimensional filters 121a and 121b. Therefore, a delay caused by the characteristics of the Butterworth three-dimensional filters 121a and 121b occurs in the phase of this electrical angle. Thus, a phase error occurs in the electrical angle due to this phase delay. Therefore, the phase correction unit 150 corrects the phase error of the electrical angle. Hereinafter, the phase delay occurring according to the characteristics of the filter is also referred to as "phase delay", and the phase error caused by the phase delay is also referred to as "phase error". As shown in FIG. 4, the phase correction unit 150 includes an angle calculation unit 151, a rotation speed calculation unit 152, a moving average filter 153, a phase correction map 154, and an adder 155.

[0023] The two-phase detection signal output from the analog angle sensor 5 is also supplied to the angle calculation unit 151. The angle calculation unit 151 calculates the mechanical angle corresponding to the supplied two-phase detection signal based on the supplied two-phase detection signal. After the calculation, the angle calculation unit 151 outputs the calculated mechanical angle to the rotation speed calculation unit 152.

[0024] The rotation speed calculation unit 152 calculates the rotation speed of the motor 4 based on the mechanical angle input from the angle calculation unit 151. The rotation speed calculation unit 152 outputs the calculated rotation speed to the moving average filter 153.

[0025] The moving average filter 153 filters the rotation speed input from the rotation speed calculation unit 152. After the filtering, the moving average filter 153 outputs the filtered rotation speed to the phase correction map 154.

[0026] The phase correction map 154 calculates a phase error correction amount based on the rotation speed input from the moving average filter 153. The phase correction map 154 outputs the calculated phase error correction amount to the adder 155.

[0027] The adder 155 receives the electrical angle from the conversion map 123 of the electrical angle detector 120 and the phase error correction amount from the phase correction map 154. The adder 155 adds the input phase error correction amount to the input electrical angle. As a result, the adder 155 outputs the electrical angle with the phase error corrected.

[0028] In the above-described control device 100, the two-phase detection signals are filtered by the Butterworth three-dimensional filters 121a and 121b to obtain the electrical angle of the motor 4. By passing through the Butterworth three-dimensional filters 121a and 121b, the angle calculation unit 122 can calculate a mechanical angle with less variation, but a phase delay occurs due to the time taken for the filtering process. For this reason, a phase error occurs in the electrical angle calculated from the detection signals filtered by the Butterworth three-dimensional filters 121a and 121b. Therefore, in the configuration shown in FIG. 4, the phase correction unit 150 corrects the phase error of the electrical angle.

[0029] However, in the configuration shown in FIG. 4, the phase correction unit 150 has a configuration including a phase correction map 154 that obtains a phase error correction amount from the rotational speed. Providing such a phase correction map 154 causes a problem that the capacity of the ROM (Read Only Memory) increases. For example, the phase correction map 154 is created by sampling the phase difference for each rotational speed while gradually changing the rotational speed of the motor 4 and storing this in the table of the ROM. As an example, in order to implement the phase correction map 154, a ROM capacity of 2 bytes × 4096 = 8192 bytes is required.

[0030] Further, in the above-described control device 100, the angle calculation unit 151 for performing phase correction calculates the mechanical angle without filtering the two-phase detection signals input from the analog angle sensor 5. Therefore, the mechanical angle calculated by the angle calculation unit 151 has a large variation. Further, the rotation speed calculation unit 152 calculates the rotation speed using the mechanical angle with a large variation. Therefore, the rotation speed calculated by the rotation speed calculation unit 152 also has a large variation. Further, the phase correction map 154 calculates the phase error correction amount using the rotation speed with a large variation. Therefore, the corrected electrical angle also has a large variation. Further, in the phase correction unit 150, the rotation speed calculation unit 152 converts from the mechanical angle to the rotation speed, and the phase correction map 154 converts from the rotation speed to the phase error correction amount. Thus, since the conversion is repeatedly performed in the phase correction unit 150, the conversion error accumulates and the conversion accuracy deteriorates.

[0031] As described above, in the conventional control device 100, there is a problem that the circuit scale becomes large because a correction map is used to correct the phase error generated by filtering the two-phase detection signals. Further, in the conventional control device 100, since the two-phase detection signals that are not filtered are converted a plurality of times in the calculation of the phase error correction amount, there is a problem that the conversion error accumulates in the calculated phase error correction amount and the conversion accuracy deteriorates.

[0032] In response to these problems, in the present embodiment, the rotation speed calculation unit for obtaining the rotation speed from the mechanical angle and the phase correction map are made unnecessary, and the phase error correction amount is calculated only from the mechanical angle. As a result, it is possible to reduce the circuit scale for converting the mechanical angle to the electrical angle and improve the conversion accuracy.

[0033] <3. Functional Configuration of Control Device According to Present Embodiment> The functional configuration of the conventional control device has been described above. Subsequently, with reference to FIGS. 2 and 3, the functional configuration of the control device according to the present embodiment will be described. FIG. 2 is a block diagram showing an example of the functional configuration of the control device according to the present embodiment. As shown in FIG. 2, the control device 6 according to the present embodiment includes a mechanical angle detection unit (first mechanical angle detection unit) 20, a mechanical angle detection unit (second mechanical angle detection unit) 30, a phase correction unit 40, and a conversion map 50 (conversion unit).

[0034] The mechanical angle detection unit 20 calculates a mechanical angle (first mechanical angle) from the detection signal of the analog angle sensor 5, converts the calculated mechanical angle into an electrical angle, and outputs it. The mechanical angle detection unit 20 includes Butterworth three-dimensional filters (first filters) 21a and 21b, and an angle calculation unit 22.

[0035] The two-phase detection signal output from the analog angle sensor 5 is supplied to the Butterworth three-dimensional filters 21a and 21b. For example, a cosine signal is input to the Butterworth three-dimensional filter 21a, and a sine signal is input to the Butterworth three-dimensional filter 21b. The Butterworth three-dimensional filters 21a and 21b filter the input signals respectively. After filtering, the Butterworth three-dimensional filters 21a and 21b output the filtered detection signals to the angle calculation unit 22.

[0036] The angle calculation unit 22 calculates a mechanical angle corresponding to the detection signal based on the two-phase detection signal filtered by the Butterworth three-dimensional filters 21a and 21b. For example, the angle calculation unit 22 calculates the mechanical angle C as shown in the following formula (1) from the two-phase detection signal composed of the cosine signal (cosθ) and the sine signal (sinθ). Mechanical angle C = sinθ / cosθ …(1)

[0037] The mechanical angle detection unit 30 calculates a mechanical angle (second mechanical angle) from the detection signal of the analog angle sensor 5, converts the calculated mechanical angle into an electrical angle, and outputs it. The mechanical angle detection unit 30 includes moving average filters (second filters) 31a and 31b and an angle calculation unit 32.

[0038] The two-phase detection signals output from the analog angle sensor 5 are also supplied to the moving average filters 31a and 31b. For example, a cosine signal is input to the moving average filter 31a, and a sine signal is input to the moving average filter 31b. The moving average filters 31a and 31b filter the input signals respectively. After filtering, the moving average filters 31a and 31b output the filtered detection signals to the angle calculation unit 32.

[0039] Based on the two-phase detection signals filtered by the moving average filters 31a and 31b, the angle calculation unit 32 calculates the mechanical angle corresponding to the detection signals. For example, the angle calculation unit 32 calculates the mechanical angle B from the two-phase detection signals consisting of a cosine signal (cosθ) and a sine signal (sinθ) as shown in the following formula (2). Mechanical angle B = sinθ / cosθ …(2)

[0040] As described above, in this embodiment, there are two sets of angle detection units, namely the mechanical angle detection unit 20 and the mechanical angle detection unit 30. The mechanical angle detection unit 20 and the mechanical angle detection unit 30 respectively obtain two mechanical angles (mechanical angles C and B).

[0041] Here, the filters for filtering the detection signals in the mechanical angle detection unit 20 are Butterworth three-dimensional filters 21a and 21b. By passing through the Butterworth three-dimensional filters 21a and 21b, the angle calculation unit 22 can calculate a mechanical angle with less variation. However, a phase delay occurs due to the time-consuming filtering process. Therefore, a phase error occurs in the electrical angle calculated from the detection signals filtered by the Butterworth three-dimensional filters 21a and 21b. That is, in the mechanical angle C calculated by the angle calculation unit 22 of the mechanical angle detection unit 20, although the variation is small, a phase error occurs.

[0042] On the other hand, the filters for filtering the detection signal in the mechanical angle detection unit 30 are the moving average filters 31a and 31b. The moving average filter has a smaller phase error caused by the shorter time required for the filtering process than the Butterworth three-dimensional filter, but has a larger variation caused by the lower filtering accuracy than the Butterworth three-dimensional filter. That is, in the mechanical angle B calculated by the angle calculation unit 32 of the mechanical angle detection unit 30, although the variation is large, a phase error smaller than that of the mechanical angle C occurs. Therefore, the mechanical angle C calculated by the angle calculation unit 22 of the mechanical angle detection unit 20 has a later phase than the mechanical angle B calculated by the angle calculation unit 32 of the mechanical angle detection unit 30.

[0043] The phase correction unit 40 corrects the phase error occurring in the mechanical angle C based on the mechanical angle C output from the mechanical angle detection unit 20 and the mechanical angle B output from the mechanical angle detection unit 20. As shown in FIG. 2, the phase correction unit 40 includes a subtractor 41, a multiplier 42, and an adder 43.

[0044] The mechanical angle C calculated by the angle calculation unit 22 of the mechanical angle detection unit 20 is output to the subtractor 41 and also output to the adder 43. The mechanical angle B calculated by the angle calculation unit 32 of the mechanical angle detection unit 30 is output to the subtractor 41.

[0045] The subtractor 41 calculates the phase difference between the mechanical angle C and the mechanical angle B. For example, the subtractor 41 subtracts the mechanical angle C from the mechanical angle B to calculate the phase difference (B - C). The subtractor 41 outputs the calculated phase difference (B - C) to the multiplier 42.

[0046] The multiplier 42 calculates a phase error correction amount for correcting the phase error of the mechanical angle C. For example, the multiplier 42 multiplies the phase difference (B - C) between the mechanical angle B and the mechanical angle C by a predetermined correction coefficient K to calculate the phase error correction amount K(B - C). The multiplier 42 outputs the calculated phase error correction amount K(B - C) to the adder 43.

[0047] Here, referring to FIG. 3, the correction coefficient K will be described. FIG. 3 is a diagram showing an example of the phase error according to the present embodiment. In FIG. 3, the horizontal axis represents time, and the vertical axis represents the mechanical angle of the motor 4.

[0048] The mechanical angle A is an ideal mechanical angle in which no phase error occurs. The mechanical angle A is calculated in advance based on, for example, a cosine signal and a sine signal that are ideal detection signals.

[0049] The mechanical angle B is the mechanical angle calculated by the angle calculation unit 32 of the mechanical angle detection unit 30. The mechanical angle detection unit 30 performs filtering using the moving average filters 31a and 31b. Therefore, a phase error occurs in the mechanical angle B.

[0050] The mechanical angle C is the mechanical angle calculated by the angle calculation unit 22 of the mechanical angle detection unit 20. The mechanical angle detection unit 20 performs filtering using the Butterworth three-dimensional filters 21a and 21b. Therefore, a larger phase error occurs in the mechanical angle C compared to the phase error that occurs in the mechanical angle B.

[0051] In the present embodiment, the subtractor 41 subtracts the mechanical angle B from the mechanical angle C (B - C). Then, the output of the subtractor 41 is multiplied by the correction coefficient K to calculate the phase error correction amount. Therefore, the phase error correction amount is K(B - C). On the other hand, the phase error that occurs in the mechanical angle detection unit 20 is the subtraction value (A - C) between the ideal mechanical angle A with no phase error and the mechanical angle C calculated by the mechanical angle detection unit 20. This phase error (A - C) in the mechanical angle detection unit 20 becomes the ideal phase error correction amount for correcting the phase error of the mechanical angle detection unit 20. If the phase error correction amount (A - C) is equal to the phase error correction amount K(B - C) obtained by multiplying the above-described correction coefficient K as shown in the following equation (3), the ideal phase error can be corrected. (A - C)=K(B - C) …(3)

[0052] From the above equation (3), the correction coefficient K is obtained as shown in the following equation (4). K = (A - C) / (B - C) …(4)

[0053] The adder 43 corrects the phase error of the mechanical angle C. For example, the adder 43 adds the phase error correction amount K(B - C) to the mechanical angle C. Thereby, the phase error of the mechanical angle C is corrected. The adder 43 outputs the mechanical angle with the corrected phase error to the conversion map 50.

[0054] The conversion map 50 converts the mechanical angle to the electrical angle. For example, the conversion map 50 takes the mechanical angle whose phase error has been corrected by the adder 43 as an input and outputs the electrical angle. In this conversion, the conversion map 50 corrects the input mechanical angle and then converts it to the electrical angle.

[0055] The control device 6 performs vector control based on the electrical angle output from the conversion map 50 and controls the drive of the motor 4. Further, the control device 6 performs PWM (Pulse With Modulation) control, sets a duty ratio according to the target rotational output of the rotor (for example, the target rotational speed TRPM), and controls the drive of the motor 4 according to the set duty ratio.

[0056] As described above, in the present embodiment, the mechanical angle of the motor 4 is obtained by the two systems of mechanical angle detection units 20 and 30 having different filter characteristics. Then, the mechanical angles calculated by the two systems of mechanical angle detection units 20 and 30 are subtracted and multiplied by a correction coefficient to calculate the phase error correction amount. Thereby, it is possible to eliminate the rotational speed calculation unit for obtaining the rotational speed from the mechanical angle and the phase correction map. Since the phase correction map becomes unnecessary, the reduction of the ROM can be achieved. Further, in the present embodiment, the phase error correction amount is calculated only from the mechanical angle, and the conversion from the mechanical angle to the rotational speed and the conversion from the rotational speed to the phase error correction amount are not performed, so errors do not accumulate and the conversion accuracy can be improved.

[0057] Therefore, the control device 6 according to the present embodiment can reduce the circuit scale for converting the mechanical angle to the electrical angle and improve the conversion accuracy. In addition, by reducing the circuit scale in the control device 6, it is possible to contribute to minimizing the resource usage in the vehicle equipped with the control device 6. Therefore, it becomes possible to contribute to Goal 9 of the Sustainable Development Goals (SDGs) led by the United Nations, which aims to build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation. In addition, by improving the conversion accuracy in the control device 6, it is possible to contribute to the efficient operation of the vehicle equipped with the control device 6. Therefore, it becomes possible to contribute to Goal 7 of the Sustainable Development Goals (SDGs) led by the United Nations, which aims to ensure access for all people to affordable, reliable, and sustainable modern energy.

[0058] In the above-described embodiment, the Butterworth three-dimensional filters 21a and 21b are used as the filters for filtering the detection signals in the mechanical angle detection unit 20, and the moving average filters 31a and 31b are used as the filters for filtering the detection signals in the mechanical angle detection unit 30. However, the present invention is not limited to such an example. For example, when a filter with high filtering accuracy is used in the mechanical angle detection unit 20 and a filter with less phase delay than the filter of the mechanical angle detection unit 20 is used in the mechanical angle detection unit 30, any filter may be used.

[0059] The embodiments of the present invention have been described above. Note that all or part of the control device 6 in the above-described embodiments may be implemented by a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize it. Here, the "computer system" is assumed to include hardware such as an OS and peripheral devices. Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, etc., and a storage device such as a hard disk incorporated in a computer system. Furthermore, the "computer-readable recording medium" also includes, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, a medium that dynamically holds a program for a short period of time, and a volatile memory inside a computer system that becomes a server or a client in that case, which holds a program for a certain period of time. Also, the above program may be for realizing a part of the aforementioned functions, and may further be realized in combination with a program already recorded in the computer system for realizing the aforementioned functions, or may be realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0060] As described above, the embodiments of this invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and designs and the like within the scope not departing from the gist of this invention are also included.

Explanation of Reference Numerals

[0061] 1... Electric power steering device, 2... Steering mechanism, 3... Torque sensor, 4... Motor, 5... Analog angle sensor, 6... Control device, 20... Mechanical angle detection unit (first mechanical angle detection unit), 21a, 21b... Butterworth three-dimensional filter (first filter), 22... Angle calculation unit, 30... Mechanical angle detection unit (second mechanical angle detection unit), 31a, 31b... Moving average filter (second filter), 32... Angle calculation unit, 40... Phase correction unit, 41... Subtractor, 42... Multiplier, 43... Adder, 50... Conversion map, 100... Control device, 120... Electrical angle detection unit, 121a, 121b... Butterworth three-dimensional filter, 122... Angle calculation unit, 123... Conversion map, 150... Phase correction unit, 151... Angle calculation unit, 152... Rotation speed calculation unit, 153... Moving average filter, 154... Phase correction map, 155... Adder

Claims

1. A first mechanical angle detection unit that calculates a first mechanical angle from the detection signal obtained by filtering the detection signal indicating the rotation angle of the motor detected by the sensor device with a first filter; A second mechanical angle detection unit that calculates a second mechanical angle from the detection signal obtained by filtering the detection signal detected by the sensor device with a second filter having a smaller phase delay than the first filter; A phase correction unit that subtracts the first mechanical angle from the second mechanical angle to calculate a phase difference between the second mechanical angle and the first mechanical angle, multiplies the phase difference by a correction coefficient to calculate a phase error correction amount, and adds the phase error correction amount to the first mechanical angle to correct the phase error of the first mechanical angle; A conversion unit that converts the first mechanical angle with the phase error corrected into an electrical angle; A control device comprising the above.

2. The first filter is a filter with higher filtering accuracy than the second filter The control device according to claim 1.

3. The first filter is a Butterworth filter, and the second filter is a moving average filter. The control device according to claim 1 or claim 2.

4. The correction coefficient is set such that the difference between the ideal mechanical angle without phase delay and the first mechanical angle is equal to the value obtained by multiplying the difference between the second mechanical angle and the first mechanical angle by the correction coefficient. The control device according to any one of claims 1 to 3.

5. The motor is a brushless motor. The control device according to any one of claims 1 to 4.

6. A first mechanical angle detection process in which the first mechanical angle detection unit calculates a first mechanical angle from the detection signal obtained by filtering the detection signal indicating the rotation angle of the motor detected by the sensor device with a first filter; A second mechanical angle detection process in which the second mechanical angle detection unit calculates a second mechanical angle from the detection signal obtained by filtering the detection signal detected by the sensor device with a second filter having a smaller phase delay than the first filter; A phase correction process in which the phase correction unit subtracts the first mechanical angle from the second mechanical angle to calculate a phase difference between the second mechanical angle and the first mechanical angle, multiplies the phase difference by a correction coefficient to calculate a phase error correction amount, and adds the phase error correction amount to the first mechanical angle to correct the phase error of the first mechanical angle; The conversion unit includes a conversion process of converting the first mechanical angle with corrected phase error into an electrical angle, and a control method including the above.

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