JP2010045908A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique that drives a motor by using accurate induced voltage waves. <P>SOLUTION: The motor 100 includes coils 21A-28A and 21B-28B of N phases (N is an integer or two or over), magnets 31-38, an induced voltage waved table 500, which has stored data on drive voltage waves added to the coils separately for each phase of the coils, and a control unit 200, which drives the motor, using the induced voltage wave table. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor using a permanent magnet and an electromagnetic coil.

  In a motor, it is known that the efficiency of the motor can be improved by making the drive voltage a shape close to the induced voltage unique to the motor generated in the electromagnetic coil (for example, Patent Document 1).

JP 2008-22639 A

  However, in the past, the actual situation was that the device was not fully devised from the viewpoint of driving the motor using an accurate induced voltage waveform.

  An object of the present invention is to solve at least one of the above-mentioned problems and to provide a technique capable of driving a motor using an accurate induced voltage waveform.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A motor, an N-phase coil (N is an integer of 2 or more), a magnet, an induced voltage waveform table storing a drive voltage waveform applied to the coil for each phase of the coil, and the induced voltage And a control unit that drives the motor using the waveform table.
According to this application example, since the induced voltage waveform table corresponding to each phase can be applied, it is possible to cope with the variation of the coil for each phase and to increase the efficiency of the motor.

[Application Example 2]
In the motor described in Application Example 1, the coil includes a plurality of coils for the same phase, and the induced voltage waveform table stores a drive voltage waveform for driving the motor for one rotation of the motor. motor.
According to this application example, since it is possible to cope with variations in the coil, it is possible to increase the efficiency of the motor.

[Application Example 3]
The motor according to Application Example 1 or Application Example 2, wherein the control unit matches the position of the magnet and the drive voltage waveform when the motor is driven.
According to this application example, since the motor can be driven with a drive voltage waveform corresponding to the position of the magnet, it is possible to increase the efficiency of the motor.

[Application Example 4]
In the motor described in Application Example 3,
An induced voltage measuring unit connected to both ends of the coil of each phase;
An induced voltage waveform acquisition unit for acquiring an induced voltage waveform using the induced voltage;
With
The control unit matches the position of the magnet and the drive voltage waveform using the induced voltage waveform and the drive voltage waveform stored in the induced voltage waveform table.
According to this application example, since the position of the magnet and the drive voltage waveform are matched using the induced voltage waveform and the induced voltage waveform table, the motor can be made highly efficient.

[Application Example 5]
In the motor according to application example 4, the control unit uses the induced voltage waveform for one rotation of the motor and the drive voltage waveform stored in the induced voltage waveform table to determine the position of the magnet and the drive voltage. A motor that matches the waveform.
According to this application example, it is possible to cope with variations among coils.

[Application Example 6]
In the motor according to Application Example 4 or Application Example 5, the control unit may perform the driving by using one of the N-phase coils as a sensor coil and the other phase as a driving coil. The motor is driven by a coil for use, and the induced voltage acquisition unit acquires an induced voltage generated in the sensor coil.
According to this application example, no other motor is required when acquiring the induced voltage.

[Application Example 7]
The motor according to Application Example 3 further includes a rotor provided with one of the magnet or the coil and an absolute encoder for detecting the position of the rotor, and the control unit is a position obtained from the absolute encoder. A motor that matches the position of the rotor and the drive voltage waveform using a motor.
According to this application example, since the position of the rotor and the drive voltage waveform are matched using an absolute encoder, it is not necessary to measure the induced voltage.

  The present invention can be realized in various forms, for example, in various forms such as a motor driving method and a control method in addition to a motor.

First embodiment:
FIG. 1 is an explanatory diagram schematically showing the configuration of the motor according to the first embodiment. 1A is a cross-sectional view taken along a plane parallel to the rotation axis, FIGS. 1B and 1C are plan views of the stator, and FIG. 1D is a plan view of the rotor. is there. The motor 100 includes stators 20A and 20B, a rotor 30, a rotating shaft 112, and a bearing 114. The stators 20A and 20B have coils 21A to 28A and 21B to 28B, respectively. The stator 20A is provided with a B-phase sensor 40B, and the stator 20B is provided with an A-phase sensor 40A. The A-phase sensor 40A and the B-phase sensor 40B are magnetic sensors for detecting the position of the rotor 30, and for example, a Hall IC can be used. The rotor 30 has permanent magnets 31 to 38. In addition, the permanent magnets 31-38 can be seen inside the coils 21A-28A, 21B-28B shown in FIGS.

  FIG. 2 is an explanatory diagram showing an example of coil connection. The coils 21A to 28A and the coils 21B to 28B are connected in series, respectively. As shown in FIGS. 1B and 1C, the currents flowing through the coils in adjacent coils are opposite to each other, that is, the currents are counterclockwise to the coils 21A, 23A, 25A, and 27A. When current flows, coils 21A to 28A are wound so that current flows clockwise through coils 22A, 24A, 26A, and 28A. The same applies to the coils 21B to 28B.

  FIG. 3 is an explanatory diagram schematically showing the overall configuration of the motor 100. The motor 100 includes a drive control unit 200, driver units 210A and 210B, a CPU 300, an induced voltage measurement unit 400, and an induced voltage waveform table unit 500. The driver units 210A and 210B are configured by, for example, an H-type bridge circuit. The drive control unit 200 drives the driver units 210A and 210B to flow current through the coils 21A to 28A and the coils 21B to 28B. At the time of measuring the induced voltage of the coil, the drive control unit 200 drives only one of the driver units 210A and 210B according to an instruction from the CPU 300. The induced voltage measurement unit 400 includes a switch 410, a voltmeter 420, and an A / D converter 430. The switch 410 switches between measurement of the induced voltage of the A-phase coils 21A to 28A, measurement of the induced voltage of the B-phase coils 21B to 28B, and non-measurement according to an instruction from the CPU 300. The voltmeter 420 measures the induced voltage. The A / D converter 430 converts the measured induced voltage from analog data to digital data. The CPU 300 creates drive voltage waveform data using the induced voltage digital data and the outputs of the sensors 40 </ b> A and 40 </ b> B and stores them in the induced voltage waveform table unit 500.

  FIG. 4 is an operation flowchart when acquiring the induced voltage data. In step S100, the CPU 300 determines whether or not the motor 100 can be driven using the A-phase coils 21A to 28A, that is, whether or not the rotor 30 is in a dead point position with respect to driving by the A-phase coils 21A to 28A. Judging. Whether or not it is at a dead point can be easily determined by determining whether or not the rotor 30 can be rotated when starting using the A-phase coils 21A to 28A, for example. If rotor 30 is not at the position of the dead point, in step S110, CPU 300 uses A-phase coils 21A-28A as drive coils (also referred to as “driving coils”), and B-phase coils 21B-28B measure the induced voltage. Coil (hereinafter also referred to as “sensor coil”). Specifically, the induced voltage measuring unit 400 switches the switch 410 to measure the induced voltage of the B-phase coils 21B to 28B. Further, the drive control unit 200 drives the motor 100 only by the driver unit 210A. At this time, since the drive voltage waveform data is not stored in the induced voltage waveform table unit 500, for example, a rectangular wave, a sine wave, or a triangular wave can be used as the drive voltage waveform for driving the driver unit 210A. It is.

  In step S120, CPU 300 causes voltmeter 420 to measure the induced voltage. Next, drive voltage waveform data is created using the acquired induced voltage and the output of the A-phase sensor 40 </ b> A and stored in the induced voltage waveform table unit 500. Here, the output of the phase A sensor 40A is used to acquire an address. In step S130, the drive control unit 200 stops the motor drive by the driver unit 210A, and the switch 410 is switched to non-measurement. The induced voltage table created in step S120 is commonly applied to the A phase and the B phase when the motor 100 is subsequently driven.

  When the rotor 30 is at a dead point position with respect to driving by the A-phase coils 21A to 28A, in step S200, the CPU 300 uses the B-phase coils 21B to 28B as driving coils and the A-phase coils 21A to 28A. A sensor coil is used. Then, the motor 100 is driven only by the driver unit 210B. In this embodiment, the permanent magnets 31 to 38 of the rotor 30 are switched between the N pole and the S pole every 45 °. On the other hand, the coils 21A to 28A and the coils 21B to 28B are shifted in angle by 22.5 °. Therefore, when the rotor 30 is at the position of the dead point for driving by the A-phase coils 21A to 28A, it is not at the position of the dead point for driving by the B-phase coils 21B to 28B.

  In step S210, CPU 300 causes voltmeter 420 to measure the induced voltage. Drive voltage waveform data is created using the measured induced voltage and stored in the induced voltage waveform table unit 500. In step S220, the drive control unit 200 stops the motor drive by the driver unit 210B, and the switch 410 is switched to non-measurement. The induced voltage table created in step S210 is commonly applied to the A phase and the B phase when the motor 100 is subsequently driven.

  It is preferable to create an induced voltage waveform table storing drive voltage waveform data for one rotation of the motor. That is, in the present embodiment, there are a plurality of coils and permanent magnets. However, since the magnetic flux density and shape are generally not completely the same, the coils and permanent magnets vary. However, if an induced voltage waveform table storing drive voltage waveform data for one rotation of the motor is created, it is possible to cope with these variations.

  FIG. 5 is an operation flowchart when the induced voltage data is acquired for all phases. Steps S100 to S120 and S200 to S210 are the same as those in the operation flowchart of FIG.

  When the creation of the induced voltage table for the B phase is completed in step S120, in step S140, the CPU 300 stops the power supply to the A phase coils 21A to 28A, uses the B phase coils 21B to 28B as drive coils, and A The phase coils 21A to 28A are sensor coils. Then, the motor 100 is driven only by the driver unit 210B. In step S150, the voltmeter 420 is caused to measure the induced voltage. Drive voltage waveform data is created using the measured induced voltage and stored in the induced voltage waveform table unit 500. In step S160, the drive control unit 200 stops the motor drive by the driver unit 210B, and the switch 410 is switched to non-measurement.

  On the other hand, when the creation of the induced voltage table for the A phase is completed in step S220, in step S230, the CPU 300 stops the power supply to the B phase coils 21B to 28B, and uses the A phase coils 21A to 28A as drive coils. The B-phase coils 21B to 28B are sensor coils. Then, the motor 100 is driven only by the driver unit 210A. In step S240, the voltmeter 420 is caused to measure the induced voltage. Drive voltage waveform data is created using the measured induced voltage and stored in the induced voltage waveform table unit 500. In step S250, the drive control unit 200 stops motor driving by the driver unit 210A, and the switch 410 is switched to non-measurement. In this operation, since the induced voltage waveform table is acquired for each phase of the coil, it is possible to cope with the variation for each phase of the coil. Further, when switching between the sensor coil and the drive coil, the rotor 30 continues to rotate due to inertia, so that no dead point occurs in the rotor 30.

  FIG. 6 is another operation flowchart when the induced voltage data is acquired. In step S105, the CPU 300 causes the drive control unit 200 to drive the motor using both the driver units 210A and 210B. In step S115, the CPU 300 causes the drive control unit 200 to stop driving by the driver unit 210B, and causes the induced voltage measurement unit 400 to switch the switch 410 to measurement of the induced voltage of the B-phase coils 21B to 28B. . The subsequent operation flowchart is the same as that after step S120 in FIG. In this operation, since the motor 100 is first driven using the coils of all phases, a dead point does not occur in the rotor 30 and the motor 100 can be reliably driven.

  FIG. 7 is an explanatory diagram illustrating the configuration of the control block of the motor 100. FIG. 8 is a timing chart of the control block. The induced voltage waveform table unit 500 includes an A phase induced voltage waveform table unit 500A and a B phase induced voltage waveform table unit 500B.

  Since the operations of the A phase and the B phase are the same, driving using the induced voltage waveform table unit 500 will be described taking the A phase as an example. The CPU 300 drives the driver unit 210A to the drive control unit 200 using, for example, a rectangular wave. The driver unit 210 causes the current to flow through the coils 21 </ b> A to 28 </ b> A and starts the rotor 30. When the rotor 30 rotates, the Hall signal HallA is output from the A-phase sensor 40A depending on the relative positions of the permanent magnets 31 to 38 on the rotor 30 and the A-phase sensor 40A. The hall signal HallA is, for example, a rectangular signal as shown in FIG. The hall signal HallA is input to the A-phase induced voltage waveform table unit 500A. The address of the A-phase induced voltage waveform table unit 500A is reset at the rising edge of the Hall signal HallA, and the reference PWM signal PwmRefA is output from the A-phase induced voltage waveform table unit 500A. The shape of the reference PWM signal PwmRefA is an induced voltage waveform as shown in FIG.

  The reference PWM signal PwmRefA is input to the drive control unit 200. PWM signals PwmAH and PwmAL are output from the drive control unit 200 to the driver unit 210. The PWM signal PwmAH is a pulse signal having the shape shown in FIG. 8 and is output when the value of PwmRefA is greater than 127. The pulse width depends on the value of PwmRefA, and the pulse width increases as the value of PwmRefA increases. The PWM signal PwmAL is also a pulse signal, but contrary to the PWM signal PwmAH, it is output when the value of PwmRefA is smaller than 127, and the pulse width increases as the value of PwmRefA decreases.

  The driver unit 210 applies drive voltage signals DrvAH and DrvAL as shown in FIG. 8 to the coils 21A to 28A and 21B to 28B in accordance with the PWM signals PwmAH and PwmAL. When the start by the rectangular wave is completed, the motor 100 is driven by the new drive voltage signals DrvAH and DrvAL generated using the induced voltage waveform table unit 500, and the above-described operation is repeated.

  FIG. 9 is an explanatory diagram schematically showing the configuration of the A-phase induced voltage waveform table section 500A. FIG. 10 is a timing chart in the induced voltage waveform table unit 500. The A-phase induced voltage waveform table unit 500A includes a PLL unit 510A and a table unit 520A. The PLL unit 510A multiplies the frequency of the hall signal HallA to generate a clock signal FlagA as shown in FIG. The table unit 520A increments the address in synchronization with the clock signal FlagA and outputs the reference PWM signal PwmRefA. Note that the hall signal HallA is also input to the table unit 520A, and the address is reset at the rising edge of the hall signal HallA.

  FIG. 11 is an explanatory diagram schematically showing another configuration of the A-phase induced voltage waveform table section 500A. The A-phase induced voltage waveform table unit 500A includes a counter unit 530A, a division unit 540A, a frequency divider 550A, and a table unit 520A. A clock signal CLK and a hall signal HallA are input to the counter unit 530A. The counter unit 530A obtains the number of clocks CNT in a period between two rising edges of the hall signal HallA. The division unit 540A divides the clock number CNT by the address number N of the table unit 520A to obtain the clock number M per address. The frequency divider 550A outputs a clock signal FlagA for each clock number M. The subsequent operation is the same as when the PLL unit 510A is used.

  FIG. 12 is a timing chart in the induced voltage waveform table unit 500 of FIG. As described above, even when the counter unit 530A, the division unit 540A, and the frequency divider 550A are used, the clock signal FlagA and the reference PWM signal PwmRefA can be obtained in the same manner as when the PLL unit 510A is used.

  As described above, according to the first embodiment, the motor 100 is driven using the B-phase coils 21B to 28B to generate the A-phase coil induced voltage, and the A-phase induced voltage waveform table is generated using the induced voltage. Drive voltage waveform data (PwmRefA) of unit 500A is acquired. Conversely, when obtaining the drive voltage waveform data (PwmRefB) of the B-phase induced voltage waveform table section 500B, the motor 100 is driven using the A-phase coils 21A to 28A. Therefore, in driving the motor when acquiring the induced voltage, driving by another motor is not required, and the induced voltage can be acquired with a simple configuration and drive voltage waveform data of the induced voltage waveform table can be generated.

  Further, by driving the motor 100 using all the N-phase coils and switching one phase coil to the sensor coil after the driving, it is possible to suppress the occurrence of so-called dead points.

  Further, in the first embodiment, the phase to be the sensor coil is switched in order and the drive voltage waveform data of the induced voltage waveform table is created, so that variations in the permanent magnets 31 to 38 and the coils 21A to 28A and 21B to 28B are generated. It becomes possible to cope with.

  In the first embodiment, since the drive voltage waveform data of the induced voltage waveform table for one rotation of the motor 100 is created, it is possible to deal with variations among coils.

Second embodiment:
FIG. 13 is an explanatory diagram schematically showing the operation of the second embodiment. In the second embodiment, the position of the rotor 30 (permanent magnets 31 to 38) and the induced voltage waveform table created in the first embodiment are matched to optimize driving. FIG. 13A is an explanatory diagram showing a state before optimization, and FIG. 13B shows a state after optimization. The configuration of the second embodiment is the same as that of the first embodiment.

  In FIG. 13A, the induced voltage waveform for one revolution of the motor and the drive voltage waveform data (hereinafter referred to as “induced voltage table value”) of the induced voltage waveform table unit 500A are shown in a graph. Here, the induced voltage waveform for one rotation of the motor is a value obtained when the motor 100 is used this time. The horizontal axis corresponds to the position of the rotor 30 (permanent magnets 31 to 38). On the other hand, the induced voltage table value is data stored when the motor 100 is used before, for example, when the motor 100 is manufactured. In this embodiment, since there are eight coils (21A to 28A) and eight permanent magnets (31 to 38), the induced voltage waveform and the induced voltage table value can be divided into four periods of the first to fourth periods. Is possible. Here, since the coils 21A to 28A and the permanent magnets 31 to 38 have variations, the induced voltage waveforms in the first to fourth periods are not necessarily the same. For example, the induced voltage waveform has the largest amplitude in the second period in the example shown in FIG. On the other hand, the induced voltage table value has the largest amplitude in the third period.

  By the way, when the motor 100 is operated with a drive voltage waveform close to the induced voltage waveform, the motor 100 can be operated efficiently. On the other hand, when the difference between the amplitude of the induced voltage waveform and the amplitude of the induced voltage table value is compared, if the error is large, the motor 100 cannot be operated efficiently. For example, as shown in FIG. 13A, when the period in which the induced voltage waveform has the maximum amplitude is different from the period in which the induced voltage table value has the maximum amplitude, the amplitude of the induced voltage waveform, The error when comparing the difference with the amplitude of the induced voltage table value is large, and the motor 100 cannot be driven efficiently. However, even in such a case, the efficiency of the motor 100 is improved by shifting and matching the induced voltage table value so that the difference between the amplitude of the induced voltage waveform and the amplitude of the induced voltage table value is minimized. It is possible to improve. In FIG. 13B, the induced voltage table value is shifted to the left by 2π as compared with FIG. As a result, the difference between the amplitude of the induced voltage waveform and the amplitude of the induced voltage table value is reduced, and the motor 100 can be operated efficiently.

  FIG. 14 is an operation flowchart when the efficiency of the motor 100 is improved. In step S300, CPU 300 determines whether to drive in A phase or B phase. When driving in the A phase, in step S310, the induced voltage generated in the B phase coils 21B to 28B is measured and temporarily stored in a memory (not shown). This step is the same as steps S110 and S120 of the first embodiment. However, since this induced voltage waveform is compared with the induced voltage table value in a later step, it is stored in an area different from the area for storing the induced voltage table value. In step S320, the CPU 300 compares the induced voltage waveform and the induced voltage table value to obtain a difference between the two.

  In step S330, the CPU 300 determines the magnetic pole position. Specifically, the induced voltage table value is shifted every one cycle (motor ¼ rotation), the induced voltage waveform is compared with the induced voltage table value, and an error is acquired for each cycle. At this time, an error between the induced voltage waveform and the induced voltage table value is obtained by, for example, the least square method. As a result, the CPU 300 can obtain the number of cycles to shift the induced voltage table value and the number of cycles to shift to minimize the error between the induced voltage waveform data and the induced voltage table value. In step S340, the application voltage application value start point is adjusted using the number of cycles acquired in step S330. In step S350, the motor 100 is driven using the induced voltage table value after application.

  If it is determined in step S400 that B-phase driving is performed, steps S410 to S450 are executed. In addition, since operation | movement of step S410-S450 is the same as operation | movement of step S310-S350, description is abbreviate | omitted.

  FIG. 15 is an explanatory diagram showing an example of comparison between the induced voltage waveform and the induced voltage table value. Here, the maximum and minimum points of the induced voltage waveform are marked with points A1 to A8, and the maximum and minimum points of the induced voltage table value are marked with points A1 'to A8'. The CPU 300 obtains an error 1 between the induced voltage waveform and the induced voltage table value using the corresponding maximum points (for example, points A1 and A1 ') and the minimum points. Next, the CPU similarly determines the error 2 by shifting the induced voltage table value by one cycle. The corresponding maximum points at this time are, for example, point A1 and point A3 '. In this embodiment, since one rotation of the motor is four cycles, error 3 and error 4 are obtained in the same manner.

  The CPU 300 compares the errors 1 to 4 and obtains the one with the smallest error. Next, how many cycles the induced voltage table value is shifted to find the smallest error. Then, the motor 100 is driven by shifting the induced voltage table value by the determined period. In addition, it is preferable to obtain | require for what period the induced voltage table value should be shifted for every phase of a coil. As a result, the efficiency of the motor 100 can be increased. Further, by calculating the error using only the maximum point and the minimum point as described above, it is possible to greatly reduce the calculation amount. Furthermore, it is not necessary to examine all combinations of the maximum value and the minimum value, and it is only necessary to obtain and compare four errors when the induced voltage table value is shifted every period.

  In this embodiment, the acquired induced voltage waveform data and the induced voltage table value, that is, the rotor 30 (permanent magnets 31 to 38) and the induced voltage table value are matched, so that the efficiency of the motor 100 is increased. It becomes possible to plan.

Variation:
FIG. 16 is an explanatory diagram illustrating a configuration of a control block of the motor 100 according to the modification. In this modification, in addition to the configuration of the second embodiment, an absolute encoder 700 for detecting the phase (angle) of the rotor 30 is provided. Thus, the induced voltage table value can be stored in association with the output (phase and angle information) of the absolute encoder 700. As a result, in the modified example, the CPU 300 can easily determine which address of the induced voltage waveform table unit 500 should use the induced voltage table value by using the output of the absolute encoder 700. Further, it is not necessary to calculate an error between the induced voltage waveform and the induced voltage table value.

  In this embodiment, the axial gap type brushless motor has been described. However, the configuration of the motor may be other configurations.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

It is explanatory drawing which shows typically the structure of the motor which concerns on a 1st Example. It is explanatory drawing which shows an example of the connection of a coil. 2 is an explanatory diagram schematically showing the overall configuration of a motor 100. FIG. It is an operation | movement flowchart at the time of acquiring induced voltage data. It is an operation | movement flowchart when acquiring induced voltage data about all the phases. It is another operation | movement flowchart when acquiring induced voltage data. 3 is an explanatory diagram illustrating a configuration of a control block of a motor 100. FIG. It is a timing chart of a control block. It is explanatory drawing which shows typically the structure of A phase induced voltage waveform table part 500A. 6 is a timing chart in the induced voltage waveform table section 500. It is explanatory drawing which shows typically another structure of A phase induced voltage waveform table part 500A. 12 is a timing chart in the induced voltage waveform table section 500 of FIG. It is explanatory drawing which shows typically operation | movement of a 2nd Example. 4 is an operation flowchart when the efficiency of the motor 100 is improved. It is explanatory drawing which shows an example of a comparison with the acquired induced voltage waveform data and an induced voltage table value. It is explanatory drawing explaining the structure of the control block of the motor 100 which concerns on a modification.

Explanation of symbols

20A ... Stator 20B ... Stator 21A-28A ... Coil 21B-28B ... Coil 30 ... Rotor 31-38 ... Permanent magnet 100 ... Motor 112 ... Rotating shaft 200 ... Drive control part 210A, 210B ... Driver part 300 ... CPU
400 ... Induced voltage measuring unit 410 ... Switch 420 ... Voltmeter 430 ... A / D converter 500 ... Induced voltage waveform table unit 500A, 500B ... Induced voltage waveform table unit 510A, 510B ... PLL unit 520A ... Table unit 530A ... Counter unit 540A: Dividing unit 550A: Frequency divider 700 ... Absolute encoder DrvAH, DrvAL ... Drive voltage signal HallA ... Hall signal PwmRefA ... Reference PWM signal FlagA ... Clock signal CLK ... Clock signal CNT ... Number of clocks

Claims (7)

A motor,
A coil of N phase (N is an integer of 2 or more);
A magnet,
An induced voltage waveform table storing a drive voltage waveform applied to the coil for each phase of the coil; and
A controller for driving the motor using the induced voltage waveform table;
Comprising a motor. The motor according to claim 1,
A plurality of the coils for the same phase,
The induced voltage waveform table stores a drive voltage waveform for one rotation of the motor. The motor according to claim 1 or 2,
The said control part is a motor which matches the position of the said magnet, and the said drive voltage waveform at the time of a motor drive. The motor according to claim 3, further comprising:
An induced voltage measuring unit connected to both ends of the coil of each phase;
An induced voltage waveform acquisition unit for acquiring an induced voltage waveform using the induced voltage;
With
The control unit matches the position of the magnet and the drive voltage waveform using the induced voltage waveform and the drive voltage waveform stored in the induced voltage waveform table. The motor according to claim 4,
The control unit matches the position of the magnet and the drive voltage waveform using the induced voltage waveform for one rotation of the motor and the drive voltage waveform stored in the induced voltage waveform table. The motor according to claim 4 or 5,
The control unit drives one of the N phase coils as a sensor coil, the other phase coil as a drive coil, and drives the motor with the drive coil.
The induced voltage acquisition unit is a motor that acquires an induced voltage generated in the sensor coil. The motor according to claim 3, further comprising:
A rotor provided with one of the magnet or coil;
An absolute encoder for detecting the position of the rotor;
With
The said control part is a motor which matches the position of the said rotor, and the said drive voltage waveform using the position acquired from the absolute encoder.

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