JP2008154314A - Motor drive device and washing machine equipped with the same - Google Patents

Abstract

An object of the present invention is to provide a motor drive device capable of detecting vibrations of a motor with high accuracy even when there are variations in the manufacture of the motor.
A motor drive device includes a drive motor 1 that generates a rotational drive force, a container 12 that is attached to the drive motor 1 and that rotates by receiving the rotational drive force of the drive motor 1, and the drive motor 1. A magnetic pole detection unit 2 for detecting the magnetic pole, a specific position detection unit for detecting a specific position of the magnetic pole of the drive motor 1, and a rotation corresponding to the magnetic pole interval of the drive motor 1 obtained based on the output of the magnetic pole detection unit 2 The RAM 8 stores the magnetic pole interval time, which is the time required for the magnetic field, and the ROM 9 stores the magnetic pole interval correction time for correcting the magnetic pole interval time. The container 12 is used by using the magnetic pole interval time and the magnetic pole interval correction time. The vibration of the drive motor 1 generated by the bias of the input contents is detected.
[Selection] Figure 1

Description

  The present invention relates to a motor drive device used in, for example, a washing machine.

  2. Description of the Related Art Conventionally, there is a motor drive device that includes a container and a motor that rotates the container. This motor drive device rotates the container at a rotational speed at which the contents put into the container stick to the inner wall of the container. At this time, if the contents are stuck to the inner wall of the container, the load torque of the motor has a periodicity for each rotation. As a result, the rotational speed of the motor fluctuates due to the periodic motion of the eccentric weight of the contents, and the motor vibrates. Therefore, a device for detecting the vibration is necessary so that the motor driving device does not operate abnormally due to the vibration of the motor.

  Many techniques for detecting motor vibration from the fluctuations in the number of revolutions have already been disclosed. For example, in Japanese Patent Application Laid-Open No. 11-244592, the magnetic pole of a motor is detected by a hall sensor, the number of rotations of the motor is calculated based on the rising interval of pulses output from the hall sensor, and this number of revolutions is put into the container. The size of the eccentric weight of the contents and the position of the eccentric weight are estimated. In this technique, the position of the eccentric weight of the content is estimated based on the cycle of fluctuations in the rotational speed of the motor that occurs each time the motor is rotated once, and abnormal vibration is detected based on the position and the amplitude of the rotational speed fluctuation. It is determined whether or not it has an eccentric weight.

  However, the above technique does not take into account motor manufacturing variations. For this reason, if the number of revolutions measured by the Hall sensor contains an error, the estimated eccentric weight size and position will differ from the actual one, so that the eccentric weight that causes abnormal vibration is detected by misjudgment. It may not be possible.

  Further, if three Hall sensors are arranged at an electrical angle interval of 120 ° in order to improve the detection accuracy of the fluctuations in the rotational speed of the motor, there are six combinations of signals detected by the Hall sensors. In this case, since the rotation angle of the motor can be further divided and measured as compared with one Hall sensor, it is easy to measure the rotational speed fluctuation.

  However, if there are a plurality of Hall sensors, there will be a new variation factor that causes variations in the mounting positions of the Hall sensors, which may adversely affect the accuracy of detecting the rotational speed.

  Even if there is no variation in the mounting position of the Hall sensor, there is a possibility that an error in the magnetic pole spacing due to the manufacturing variation of the motor will occur. For example, it is desirable that the permanent magnets used in the motor are equally arranged with the same magnetic force and length. In the case of a motor that does not vary in manufacturing and operates at a constant rotational speed, the magnetic pole intervals detected by the Hall sensor are all the same during one rotation of the motor.

  However, in practice, there are variations in the magnetization, length, magnetic force, etc. of the magnets, so that an error occurs in the magnetic pole interval detected by the Hall sensor even if the motor rotation speed is exactly the same.

  In addition, as the rotational speed of the motor increases, the inertial force increases and the current state is maintained, so that a rapid fluctuation in the rotational speed of the motor is less likely to occur.

  On the other hand, the error in the magnetic pole spacing due to the manufacturing variation of the motor does not change after the motor assembly, and a detection error due to the manufacturing variation occurs every time the Hall sensor passes the same magnetic pole every time the motor rotates. For this reason, even if the number of rotations of the motor is changed, the generation ratio of the error in the magnetic pole spacing due to manufacturing variation to the number of rotations does not change.

  In other words, when the container is rotated at a high speed, the error rate due to manufacturing variations in the measured magnetic pole spacing increases, and the detection accuracy of the rotational speed fluctuation due to the eccentric weight to be originally measured decreases.

  FIG. 14 shows the rotational speed fluctuation of the motor when the rotational speed is different for the same eccentric weight. Assuming that the rotational speed deviation with respect to the reference rotational speed of the motor is the rotational speed fluctuation rate, the rotational speed fluctuation rate when the container is rotated at 110 rpm is a periodicity every time the motor rotates once, even if manufacturing variations are included. Therefore, it can be read that there is an eccentric weight.

  However, when the container is rotated at 900 rpm, the influence of manufacturing variation is large, and the fluctuation in the number of rotations per one motor cycle caused by the eccentric weight cannot be read.

  As described above, when detecting the vibration of the motor from the fluctuation of the rotational speed of the motor, there is a problem that a detection error due to manufacturing variation is included. Due to this error, the accuracy of vibration detection due to the eccentric weight to be originally measured is deteriorated. Therefore, vibration that must be judged as abnormal vibration cannot be detected, and there is a possibility that the motor drive device may fall into a dangerous state. There is a need.

  The correction for the manufacturing variation of the motor corrects only the rotational speed variation caused by the manufacturing variation of the motor, and should not adversely affect the rotational speed variation caused by other conditions.

  In particular, it is necessary to determine a correction value that does not depend on the contents under the condition that the contents are changed each time the motor driving device is used.

  Further, it is assumed that a correction operation for a manufacturing variation of a motor is performed at a certain rotation speed and the correction amount is measured. However, when compared with the result of measuring the correction amount at a different rotation speed, the reference for determining that there is no fluctuation in the rotation speed differs because the rotation speed is different. That is, the correction amount also changes depending on the rotation speed. For this reason, if there are various rotational speeds at which the vibration detection is desired, a correction amount corresponding to each rotational speed is required. However, the larger the command rotational speed, the larger the correction value to be stored. There is.

  In addition, in order to detect vibration of the motor driving device with the contents inserted, it is necessary to perform correction for the same position as the rotational speed fluctuation caused by the manufacturing variation of the motor.

  In addition, when there are various rotational speeds at which the vibration detection is to be performed, the magnetic pole detection interval time (the time required for rotation corresponding to the magnetic pole interval) at the rotational speed to be performed becomes shorter as the speed becomes higher, and the reference constant rotational speed The difference with the magnetic pole detection interval time at is small. As a result, even if the vibration is large, the observed result value does not become small. Therefore, a threshold value for determining the abnormal vibration is required for the number of rotations for which vibration detection is performed.

  Even if the vibration detection is corrected, if the contents in the container change as the motor rotates, vibration cannot be detected because there is no periodicity. Therefore, it is necessary to limit the range of use.

In addition, when the motor driving device is applied to a washing machine or a washing / drying machine, if an erroneous determination of vibration detection due to manufacturing variations occurs, vibration that should be considered as abnormal vibration cannot be suppressed. Problems such as breakage of the dryer and contact with the surroundings due to movement of the machine occur.
Japanese Patent Laid-Open No. 11-244592

  Therefore, an object of the present invention is to provide a motor drive device that can detect vibrations of a motor with high accuracy even when there are manufacturing variations in the motor.

  When the magnetic field of a magnet mounted on a motor is detected by, for example, a hall sensor, if there are variations such as the magnet's magnetization, magnet arrangement and length during assembly, the hall sensor The signal detection interval is measured differently for each magnetic pole interval.

  However, these manufacturing variations do not change after the assembly of the motor. When the same magnetic pole passes in front of the Hall sensor, a detection interval error due to the manufacturing variation occurs due to the rotation of the motor. For this reason, even if the number of rotations of the motor is changed, the manufacturing variation degree of the magnetic pole detection interval in the Hall sensor does not change.

  For this reason, the Hall sensor signal detection interval time measured for vibration detection includes the Hall sensor detection interval variation due to the state that the contents are partially eccentric weight, and the Hall sensor detection interval variation due to manufacturing variations at the same time. Therefore, it is not possible to acquire only the Hall sensor detection interval variation due to the eccentric weight, and it is impossible to perform highly accurate vibration detection.

  Therefore, paying attention to the fact that errors in the Hall sensor detection interval due to manufacturing variations always occur even when there is no eccentric weight, the error in the detection interval due to manufacturing variations is measured before the contents are inserted. Then, a value for correcting the manufacturing variation is calculated.

  And, when the contents are put into the container and the magnetic pole detection interval due to rotation is measured, the manufacturing variation is corrected, so that the detection accuracy of the rotational speed fluctuation generated by the eccentric weight of the contents can be improved. .

That is, the motor drive device of the present invention is
A motor that generates rotational driving force;
A container that is attached to the motor and rotates by receiving the rotational driving force of the motor;
A magnetic pole detector for detecting the magnetic pole of the motor;
A specific position detector for detecting a specific position of the magnetic pole of the motor;
A magnetic pole interval time storage unit that stores a magnetic pole interval time that is a time required for the rotation of the magnetic pole interval of the motor and is calculated based on the output of the magnetic pole detection unit;
A magnetic pole interval correction time storage unit for storing the magnetic pole interval correction time for correcting the magnetic pole interval time,
Using the magnetic pole interval time and the magnetic pole interval correction time, the motor vibration generated by the bias of the contents put in the container is detected.

  According to the motor drive device having the above configuration, the error due to manufacturing variation in the magnetic pole interval time can be corrected by using the magnetic pole interval correction time.

  Accordingly, since only the motor speed fluctuation caused by the eccentric weight of the contents put in the container can be observed, the motor vibration can be detected with high accuracy based on the speed fluctuation.

In the motor drive device of one embodiment,
A plurality of values are obtained by correcting the plurality of magnetic pole interval times acquired during one rotation of the motor with the magnetic pole interval correction time, and the maximum value among the plurality of values and the plurality of values in the plurality of values are obtained. A motor vibration detection unit that detects the vibration of the motor based on a difference from the minimum value is provided.

In the motor drive device of one embodiment,
The magnetic pole interval time storage unit includes a plurality of the magnetic poles measured while the motor is rotated once when the container in a state where the contents are not charged is rotated at a predetermined no-load reference rotational speed. The interval time is saved.

  According to the motor drive device of the above-described embodiment, by using a plurality of magnetic pole interval times measured in a state where the contents are not charged, only errors due to manufacturing variations in the magnetic pole interval times can be corrected.

In the motor drive device of one embodiment,
The magnetic pole interval correction time is a correction value calculated based on the no-load reference rotation speed and the actual rotation speed of the motor.

  According to the motor drive device of the above embodiment, the magnetic pole interval correction time is a correction value calculated using the no-load reference rotation speed and the actual rotation speed of the motor. The number of magnetic pole interval correction times to be saved can be reduced.

  For example, in order to detect the vibration of the motor, when the operation for detecting fluctuations in the rotational speed of the motor is performed at a plurality of rotational speeds, the pole detection interval measured at the rotational speed at which the detection is performed and the rotational speeds already specified By calculating the ratio of the correction time, a value to be used for correction can be calculated with the number of rotations at which the detection is performed, and the accuracy of vibration detection can be improved while reducing the storage area.

In the motor drive device of one embodiment,
A plurality of magnetic pole interval times are acquired while the motor makes one revolution at the actual rotation number, and a plurality of values are acquired by correcting the magnetic pole interval times with the magnetic pole interval correction time. The vibration of the motor is detected based on the difference between the maximum value among the plurality of values and the minimum value among the plurality of values.

  According to the motor drive device of the above embodiment, after measuring the magnetic pole detection interval time continuously for one rotation of the motor, correcting the manufacturing variation with respect to the magnetic pole detection interval time, and then starting from the corrected magnetic pole detection interval time. The obtained rotational speed fluctuation can be only the fluctuation due to the contents put in the container.

  Furthermore, by measuring one rotation of the motor divided into the number of pole pairs, it is possible to determine the highest and lowest magnetic pole intervals in each magnetic pole detection interval time. It is possible to determine the vibration by obtaining the fluctuation amplitude.

  That is, a plurality of magnetic pole interval times are acquired while the motor makes one revolution at an actual rotation number, and a plurality of values are acquired by correcting the plurality of magnetic pole interval times with a magnetic pole interval correction time. By detecting the vibration of the motor based on the difference between the maximum value among the values and the minimum value among the plurality of values, the detection accuracy of the magnitude of the motor vibration can be improved.

In the motor drive device of one embodiment,
A plurality of magnetic pole interval times are acquired while the motor makes one revolution at the actual rotation number, and a plurality of values are acquired by correcting the magnetic pole interval times with the magnetic pole interval correction time. The vibration of the motor is detected based on the difference between the maximum value among the plurality of values and the minimum value among the plurality of values and the ratio of the actual rotational speed to the no-load reference rotational speed. I made it.

  According to the motor drive device of the above embodiment, when the operation for detecting the rotational speed fluctuation of the motor is performed at a plurality of rotational speeds in order to detect the vibration of the motor, the magnetic pole detection interval becomes shorter as the rotational speed is higher. . For this reason, since the amplitude of the rotational speed fluctuation generated by the contents is also relatively small, by using the value calculated as the rotational speed fluctuation ratio by multiplying the ratio of the rotational speed to be measured and the reference rotational speed. It is possible to determine vibration.

  That is, a plurality of magnetic pole interval times are acquired while the motor makes one revolution at an actual rotation number, and a plurality of values are acquired by correcting the plurality of magnetic pole interval times with a magnetic pole interval correction time. The magnitude of the motor vibration is detected by detecting the motor vibration based on the difference between the maximum value among the values and the minimum value among the plurality of values and the ratio of the actual speed to the no-load reference speed. The accuracy of detection can be increased.

In the motor drive device of one embodiment,
The actual rotational speed is the rotational speed at which the contents in the container stick inside the container due to centrifugal force.

  According to the motor drive device of the above embodiment, the vibration detection rotational speed used for detecting the vibration of the motor is the rotational speed at which the contents in the container stick to the inner wall of the container. Can be made periodic.

In the motor drive device of one embodiment,
The specific position detector is a container specific position detector that detects the position of the specific part of the container.

  The washing machine of the present invention includes the motor drive device of the present invention.

  According to the washing machine having the above configuration, since the motor driving device is provided, the detection accuracy of abnormal vibration due to the eccentric weight of the laundry can be improved, for example, by detecting the vibration of the motor during the dehydrating operation.

  As a result, it is possible to prevent abnormal washing of the washing machine and to shorten the dehydrating operation time, and therefore, it can be expected to reduce the power consumption.

In one embodiment of the washing machine,
A drying device is provided for drying the contents charged in the container.

  According to the motor driving apparatus of the present invention, it is possible to correct an error due to manufacturing variation in the magnetic pole interval time by using the magnetic pole interval correction time.

  Accordingly, since only the motor speed fluctuation caused by the eccentric weight of the contents put in the container can be observed, the motor vibration can be detected with high accuracy based on the speed fluctuation.

  Hereinafter, a motor drive device of the present invention will be described in detail with reference to embodiments shown in the drawings.

(First embodiment)
FIG. 1 shows a motor drive device according to a first embodiment of the present invention.

  The motor drive device includes a drive motor 1 that is a three-phase brushless DC motor, a magnetic pole detection unit 2, a microcomputer 3, an inverter circuit 4, a position detection unit 11, and a container 12. Drive control is performed by inverter control by the inverter circuit 4. The motor drive device employs a direct drive system in which a container 12 whose rotation axis is substantially horizontal is directly attached to the drive motor 1. The drive motor 1 is an example of a motor, and the position detector 11 is an example of a specific position detector.

  As shown in FIG. 2, the drive motor 1 has a magnet rotor 13 in which N-pole permanent magnets and S-pole permanent magnets are alternately arranged in the circumferential direction. The drive motor 1 has 10 counter electrodes.

  The inverter circuit 4 is supplied with an applied voltage signal from a microcomputer 3 (hereinafter referred to as “microcomputer 3”) as an example of a control device, and outputs an applied voltage to the drive motor 1 based on this signal.

  The magnetic pole detection unit 2 has one Hall sensor 14 that faces the magnet rotor 13 from the outside in the radial direction. The Hall sensor 14 detects the moment of switching between the N pole and the S pole of the permanent magnet. The magnetic pole detection unit 2 can detect every rotation of the drive motor 1 with 10 pole pairs by a mechanical angle of 36 ° by the hall sensor 14 and output a magnetic pole position signal to the microcomputer 3.

  The position detection unit 11 outputs a signal to the motor output voltage calculation unit 10 when the container 12 rotates and the specific part of the container 12 comes to a specific position. This signal is output every rotation of the drive motor 1. Further, the position of the drive motor 1 corresponding to the signal detection position is set as the reference position of the drive motor 1.

  More specifically, as shown in FIG. 15, the position detection unit 11 is a photoelectric non-contact rotation detector that detects a reflective material 17 as an example of the specific unit, and is fixed to a support base 15. Yes. The reflector 17 is installed at one place on the outer surface of the bottom of the container 12. Here, when viewed from the rotational axis direction of the container 12, the reflecting material 17 draws a trajectory that overlaps the position detection unit 11 when the container 12 rotates. Thereby, the position detection unit 11 detects the reflecting material 17 once every time the container 12 rotates once. The rotational position of the drive motor 1 at the moment when the reflecting material 17 is detected is set as a reference position.

  Further, the reflector 17 is installed with attention to the installation angle so that the magnetic pole detection unit 2 does not detect the switching of the magnetic poles. That is, when the position detection unit 11 detects the reflecting material 17, the position detection unit 11 is installed so that the Hall sensor 14 does not detect the interchange between the N pole and the S pole of the permanent magnet. In addition, a non-reflective material having the same weight may be installed at the reference position with respect to the rotation axis of the container 12 so that the weight of the container 12 is not biased by the reflective material 17.

  In FIG. 15, 16 is a stator and 18 is a motor case.

  Although not shown, the position detection unit 11 includes a light emitting element that emits light to be applied to the reflecting material 17 and a light receiving element that receives the light reflected by the reflecting material 17.

  The microcomputer 3 drives and controls the drive motor 1 based on the command motor rotational speed input by an operation performed on the motor drive device. These controls are performed in software according to a program.

  The microcomputer detects the rotation angle of the drive motor 1 (hereinafter referred to as “motor rotation angle”) from the magnetic pole position detected by the magnetic pole detection unit 2 and the magnetic pole detection unit 2. The rotational speed calculation unit 6 that calculates the rotational speed of the drive motor 1 from the magnetic pole position (hereinafter referred to as “motor rotational speed”), and the applied voltage signal output to the inverter circuit 4 is the rotational angle of the drive motor 1 and A motor output voltage calculation unit 10 that calculates based on the rotational speed, a timer 7 that measures time, a RAM (random access memory) 8 and a ROM (read only memory) 9 that store data have. The RAM 8 is an example of a magnetic pole interval time storage unit, and the ROM 9 is an example of a magnetic pole interval correction time storage unit.

  The rotation speed calculation unit 6 measures the detection interval of the magnetic pole position signal output from the magnetic pole detection unit 2, and calculates the rotation speed of the drive motor 1 from the measured time. The Hall sensor 14 of the magnetic pole detector 2 detects the switching of the magnetic pole from the N pole to the S pole of the magnet, and can detect each rotation angle 360 degrees equally divided by the number of pole pairs. . That is, in the first embodiment, since the number of pole pairs is 10, detection is possible at every rotation angle 36 ° of the drive motor 1. Here, in order to obtain an angle other than 36 °, by measuring the magnetic pole detection interval of the Hall sensor 14, the motor rotation speed and the motor rotation angle during the time without the magnetic pole position signal are calculated. That is, the rotational speed can be calculated by measuring the time elapsed for the drive motor 1 to rotate at a mechanical angle of 36 °.

  The angle calculation unit 5 calculates a motor rotation angle based on the magnetic pole position signal input from the magnetic pole detection unit 2 and the motor rotation number calculated by the rotation number calculation unit 6. More specifically, the motor is based on the elapsed time from the magnetic pole switching position detected immediately before by the Hall sensor 14 provided in the drive motor 1 to the currently detected magnetic pole switching position and the calculated motor rotation speed. Calculate the rotation angle.

  In the microcomputer 3 according to the first embodiment, the timer 7 measures the time from when the magnetic pole is switched from the N pole to the S pole until the time when the magnetic pole is switched from the S pole to the N pole as the signal detection interval time. . At this time, the resolution of the time measured by the timer 7 is set to 2 μsec using the 32 frequency dividing function of the operation clock 16 MHz of the microcomputer 3. The motor rotational speed is calculated using the signal detection interval time detected by the hall sensor 14.

  The motor output voltage calculation unit 10 includes a command motor rotation number input by an operation performed on the motor driving device, a motor rotation number calculated by the rotation number calculation unit 6, and a motor calculated by the angle calculation unit 5. The applied voltage signal is calculated based on the rotation angle, and the calculated applied voltage signal is output to the inverter circuit 4.

  The position detector 11 detects a signal at one position at a specific position of the container 12 during one rotation of the drive motor 1. This position is set as a reference position. The magnetic pole interval passing in front of the Hall sensor 14 when the reference position is detected is defined as the first detection interval, and the magnetic pole interval passing in front of the Hall sensor 14 is the second detection interval, and then The magnetic pole interval detected by the Hall sensor 14 is defined such that the magnetic pole interval passing in front of the Hall sensor 14 is a third detection interval. Thereby, a motor position obtained by dividing one rotation of the drive motor 1 into 10 can be determined as each detection interval.

  Hereinafter, an outline of vibration detection in the motor drive device will be described.

  The container 12 is rotated by the drive motor 1 while the contents are contained in the container 12 whose rotation axis is substantially horizontal. In this case, if the centrifugal force due to the rotation is superior to the gravity of the contents, the contents rotate while being stuck to the inner wall of the container 12.

  When the content is rotated while the content is stuck to the inner wall of the container 12, the output torque generated by the drive motor 1 is constant or fluctuates slightly, and a part of the content has an eccentric weight. When the weight is in the rotational position where it is lifted from the lower part to the upper part, the load torque increases due to the gravitational component and deceleration occurs. So accelerated.

  That is, the rotational position at which the rotational speed becomes the highest speed / the lowest speed is determined depending on the location where the eccentric weight exists, and the drive motor 1 has a rotational speed fluctuation having a periodicity for each rotation. When this rotational speed fluctuation is large, the vibration of the motor drive device also increases.

  Therefore, if the signal detection interval time detected by the Hall sensor 14 (hereinafter referred to as “Hall sensor detection interval time”) is continuously measured for the number of pairs of 10 poles that constitute one rotation of the drive motor 1, the eccentric weight increases. It is possible to measure a sinusoidal discrete value having the longest detection time in the Hall sensor signal detection range that decelerates due to the shortest time and the shortest detection time in the range that accelerates by descending. The difference between the maximum value and the minimum value of the detection time for one rotation of the drive motor 1 is the value of the rotational speed fluctuation caused by the eccentric weight.

  When it is determined that the value of the rotation speed fluctuation hinders safe operation of the motor drive device, it is determined that abnormal vibration has occurred. After this, it is necessary to control the drive motor 1 and perform processing for abnormal vibration. However, there are various methods such as stopping or decelerating, not increasing the number of rotations, and once decelerating the number of rotations.

  Hereinafter, a correction method for the first to tenth detection intervals detected by the hall sensor 14 will be described with reference to the flowchart of FIG. 3.

  First, the container 12 is placed in a no-load state in which no contents are contained, and is operated at a motor command rotation number for detecting vibration (S301).

  While the specific position of the drive motor 1 is detected by the position detector 11, the Hall sensor detection interval time is simultaneously measured.

  As the motor command rotational speed, a rotational speed higher than that attached to the outer wall of the container 12 when contents are contained is set. Further, the motor drive device is operated at a rotation speed that is known to have the smallest vibration, avoiding the rotation speed at which the vibration is amplified by the natural frequency or resonance of the motor driving device.

  In the motor drive device of the first embodiment, the vibration under no load was the smallest at 400 rpm.

  Therefore, the drive motor 1 is accelerated using 400 rpm as the reference motor command rotational speed ω *. When the rotational speed of the drive motor 1 reaches 400 rpm, the process proceeds to measurement of the Hall sensor detection interval time generated due to manufacturing variations (S302).

  In order to observe the manufacturing variation, it is necessary to obtain correction values for all of the first to tenth detection intervals. Therefore, the position detection unit 11 starts measurement from the magnetic pole interval determined as the motor reference position, that is, the first detection interval. (S303).

  Next, the Hall sensor detection interval time is actually measured (S304). This Hall sensor detection interval time is stored in the RAM 8.

If there is no manufacturing variation in the drive motor 1 and the motor rotates at a constant reference motor command rotational speed of 400 rpm, the Hall sensor detection interval time is
1 / {(400 [rpm] / 60 [sec]) × 10 [number of pole pairs]} = 15 [msec]
It becomes.

When the Hall sensor detection interval time is set to the reference rotation speed counter value H * measured by the timer 7,
H * = 15 [msec] / 2 [μsec] = 7500
And should be 7500.

However, if there is a manufacturing variation in the drive motor 1, the difference between the reference rotational speed counter value H * and the counter value Hn of the actually measured Hall sensor detection interval time is obtained as follows. The counter value Hfn of the Hall sensor detection interval correction time for the variation can be acquired (S305).
Hfn = H * −Hn
Hfn: n in the detection interval (n is 1 to 10, that is, n is 1 to the number of pole pairs)
Counter value of the sensor detection interval correction time Hn: The counter value of the hall sensor detection interval time measured at the n-th (n is 1 to 10, ie, n is 1 to the number of pole pairs) detection interval.

  The calculated counter value of the hall sensor detection interval correction time is stored in the order of detection in the ROM 9 where the value is stored even when the apparatus is turned off (S306).

  Next, it is determined whether or not the drive motor 1 has made one revolution. If it is determined that the drive motor 1 has not made one revolution, the process returns to step S304, whereas if it is determined that the drive motor 1 has made one revolution, the acquisition of the Hall sensor detection interval correction time Hfn is terminated (S307).

  That is, the hall sensor detection interval correction time Hfn for each motor angle of 36 ° is set in the ROM 9 by performing the above S304 to S306 continuously for 10 pole pairs while the drive motor 1 makes one rotation.

  As a result of the measurement in the present embodiment, the Hall sensor detection interval time of each detection interval is a result as shown in FIG. 4 and is not operating at a constant rotational speed. This is a detection interval time error caused by product variations. Therefore, the hall sensor detection interval correction time is set as shown in FIG.

  The no-load operation for determining the Hall sensor detection interval correction time may be performed at the production site of the motor drive device. Of course, it may be performed in an environment where the apparatus is actually used. However, it must be completed before the contents are added. Further, the Hall sensor detection interval correction time may be measured a plurality of times, and the Hall sensor detection interval correction time for each magnetic pole interval may be averaged.

  Subsequently, the measurement operation of the rotational speed fluctuation in the state where the contents are put in the container 12 will be described.

  Hereinafter, the correction method of the 1st-10th detection interval in the said measurement operation | movement is demonstrated according to the flowchart of FIG.

  In the first embodiment, since the vibration in the state in which the contents are put into the container 12 is detected, the motor rotation speed for performing the vibration detection is the same as the reference motor command rotation speed 400 rpm for which the Hall sensor detection interval correction time is measured. Accelerate to the rotational speed (S601).

  At this time, the motor output torque may be constant, or the output torque may be slightly changed by speed control with a weak control gain. When speed control is performed and the rotation speed of the motor is controlled to be constant, the Hall sensor detection interval time slightly increases / decreases due to the control than when the output is constant. As a result, the accuracy of vibration detection is degraded, but if the output torque is kept constant due to the load being applied, depending on the position of the eccentric weight, sudden vibration may occur. Any speed control that does not cancel out may be performed.

  In a state where the rotational speed of the drive motor 1 is rotated at 400 rpm, the measurement is started from the magnetic pole interval determined as the reference position of the motor by the position detection unit 11, that is, the first detection interval (S602).

  Next, the Hall sensor detection interval time is actually measured (S603). This value is a measurement value including both the fluctuation of the Hall sensor detection interval time due to the contents and the manufacturing variation of the drive motor 1.

  Therefore, correction for manufacturing variations of the drive motor 1 is performed using the counter value of the Hall sensor detection interval correction time measured and stored in the ROM 9 previously.

That is, the counter value Hfn of the Hall sensor detection interval correction time acquired in Step S305 of the magnetic pole interval measured in Step S603 is read from the ROM 9, and the counter value Hfn and the measured Hall sensor detection interval measured in Step S603 are read. The time counter value Hn ′ is added as follows (S604, S605). This operation is continuously performed until one rotation of the drive motor 1, and the calculation result is stored in the RAM 8 (S606).
Hvn = Hn ′ + Hfn
Hvn: nth (where n is 1 to 10, that is, n is from 1 to the number of pole pairs) Manufacturing at a detection interval
Counter value of Hall sensor detection interval time corrected for variation Hn ′: nth (n is 1 to 10, that is, n is 1 to the number of pole pairs) Measured at the detection interval
Hall sensor detection interval counter value

  By executing the above steps S603 to S605 for 10 detection intervals continuously, the RAM 8 can calculate the Hall sensor detection interval time in which the error due to the manufacturing variation for each motor angle of 36 ° is corrected.

  FIG. 7 shows the magnetic pole interval time correction operation in the first embodiment. Hn ′ before correction is corrected to the Hall sensor detection interval time Hvn by performing the correction operation from S601 to S606, and the error in the detection interval caused by manufacturing variation is removed, and the rotational speed fluctuation caused by the contents It becomes possible to get only. As a result, the vibration generated by the eccentric weight of the contents can be detected with high accuracy by observing the rotational speed fluctuation.

Next, vibration detection is performed. A difference between Hvn stored in the RAM 8 and the reference rotation speed counter value H * is calculated from Hvn calculated as an example of the vibration detection method, and the magnitude of the rotation speed fluctuation is determined based on the calculation result.
Hdn = Hvn−H *
Hdn: Contents at the detection interval n (n is 1 to 10, that is, n is 1 to the number of pole pairs)
Counter value of difference in detection interval due to objects

  As a result, it was possible to calculate a value corresponding to the deviation of the rotational speed that causes the vibration with the manufacturing variation corrected (see FIGS. 8 and 9).

Further, the difference between the maximum value and the minimum value of Hd is set as the first vibration detection amount. It can be said that the larger the first vibration detection amount, the larger the rotational speed fluctuation and the greater the vibration (S607). Note that step S607 is an example of the motor vibration detection unit.
Hd = Hdmax−Hdmin
Hd: first vibration detection amount Hdmax: maximum counter value of Hd Hdmin: minimum value of maximum counter value of Hd In the first embodiment, Hd = 38 − (− 39) = 77.

  Regarding the operation after determining the first vibration detection amount, various methods are conceivable as to how to set the vibration countermeasure. For example, there are a method of determining that it is dangerous if a certain threshold is exceeded, and stopping the rotation of the drive motor 1, and a method of not performing further acceleration. Of course, vibration countermeasures may be performed by other methods.

  In the first embodiment, the container 1 whose rotation axis is substantially horizontal is used. However, a container whose rotation axis is inclined with respect to the horizontal direction may be used.

(Second Embodiment)
The motor drive apparatus according to the second embodiment of the present invention has the same configuration as that of the first embodiment.

  That is, the motor drive apparatus of the second embodiment also includes the drive motor 1, the magnetic pole detection unit 2, the microcomputer 3, the inverter circuit 4, the position detection unit 11, and the container 12 shown in FIG.

  In the first embodiment, the rotation speed at which vibration detection is performed is the same as the reference motor command rotation speed. However, in the second embodiment, the rotation speed at which vibration detection is performed is different from the reference motor command rotation speed.

  More specifically, the operation for determining the Hall sensor detection interval correction time is performed at the reference motor command rotational speed of 400 rpm using the same method as in the first embodiment. Assume that the Hall sensor detection interval correction time used in the second embodiment is the same as that in the first embodiment and is set in FIG.

  Next, a method for measuring the rotational speed fluctuation according to the second embodiment will be described with reference to the flowchart of FIG.

  In the second embodiment, a case where the number of rotations at which vibration detection is desired is 1000 rpm will be described.

  First, the motor is accelerated with a motor command rotational speed ω of 1000 rpm. When the number of revolutions reaches 1000 rpm, the process proceeds to measurement of the Hall sensor detection interval time generated due to manufacturing variation (S1001).

  In order to observe the manufacturing variation, correction values for all of the first to tenth detection intervals are required. Therefore, the position detection unit 11 starts measurement from the magnetic pole interval determined as the reference position of the motor, that is, the first detection interval. (S1002).

  Next, the Hall sensor detection interval time is actually measured (S1003).

The rotation speed of the drive motor 1 is constant at 1000 rpm, and the Hall sensor detection interval time is
1 / {(1000 [rpm] / 60 [sec]) × 10 [number of pole pairs]} = 6 msec
It becomes.

When the reference rotation speed counter value obtained by measuring the Hall sensor detection interval time with the timer 7 is Hs, the following is obtained.
Hs = 6 msec / 2 μsec = 3000

  The Hall sensor detection interval correction time acquired in step S305 of the magnetic pole interval measured in step S1003 is read from the ROM 9 (S1004).

  However, in order to correct the variation by using the counter value of the Hall sensor detection interval correction time stored in the ROM 9, the operating rotational speed is different from that of the first embodiment, so that the degree of fluctuation in the rotational speed is increased. It will be different.

  The simplest method for solving this problem is to prepare a counter value for the Hall sensor detection interval correction time with the reference motor command rotational speed set at 1000 rpm.

  However, if the rotation speed range for vibration detection is wide, the number of counter values for the Hall sensor detection interval correction time stored in the ROM 9 increases and the ROM capacity increases.

  In addition, there arises a problem that the number of operations with no load necessary for setting the Hall sensor detection interval correction time also increases.

  In order to solve this problem, the hall sensor detection interval correction time for one type of reference motor command rotation speed stored in the ROM 9 is used to correspond to the command rotation speed at which vibration detection is performed.

  Regardless of the number of rotations of the drive motor 1, the manufacturing variation is fixed at the position where the drive motor 1 occurs at the rotation angle. Therefore, when the rotation speed of the drive motor 1 is changed, it is possible to obtain manufacturing variations at various rotation speeds using the ratio between the reference motor command rotation speed and the measurement reference rotation speed.

By reading out the Hall sensor detection interval correction time having the same detection position from the position detection unit 11 from the ROM 9 and obtaining the Hall sensor detection interval correction time corresponding to the rotational speed of the drive motor 1 by the following formula, vibration detection is performed. It is not necessary to store the Hall sensor detection interval correction time in the ROM for each rotation speed to be implemented, and the ROM capacity can be reduced (S1005).
Hfen = Hfn × (ω * / ω)
Hfen: nth (n is 1 to 10, i.e., n is 1) corresponding to the rotation speed at which vibration detection is performed
To the number of pole pairs) Counting the Hall sensor detection interval correction time in the detection interval
Data value

The Hall sensor detection interval correction time Hfen corresponding to the command rotational speed is added to the Hall sensor detection interval time measured in S1003 to correct for manufacturing variations, and stored in the RAM 8 (S1006).
Hven = Hn ”+ Hfen
Hven: nth at the command rotational speed ω (n is 1 to 10, that is, n is from 1 to the number of pole pairs)
) Counter value of Hall sensor detection time interval after correction of detection interval Hn ″: nth (n is 1 to 10, that is, n is from 1 to the number of pole pairs) Measured at the detection interval
Counter value of the hall sensor detection interval

  By performing the above steps S1003 to S1006 continuously until one rotation of the driving motor 1, the Hall sensor detection interval time in which the error due to the manufacturing variation for each motor angle of 36 ° is corrected in the RAM 8 can be calculated (S1007).

  FIG. 11 shows the magnetic pole interval time correction operation in the second embodiment. Hn ″ before correction is corrected to the Hall sensor detection interval time Hven by performing the correction operation from S1001 to S1007 on the rotation, the detection interval error caused by the manufacturing variation is removed, and the rotation generated by the contents As a result, the vibration generated by the eccentric weight of the contents can be detected with high accuracy by observing the rotational speed fluctuation. As described above, the Hall sensor detection interval correction time stored in the ROM 9 can be set to only the reference motor command rotational speed.

Subsequently, only the difference in detection interval time caused by the eccentric weight is output.
Hdn = Hven-Hs
Hdn: nn is 1 to 10, that is, n is from 1 to the number of pole pairs.
Counter value of detection interval time by

  As a result, even if the command rotational speed is changed, a value corresponding to the rotational speed deviation that causes vibration can be calculated (FIGS. 12 and 13).

However, if the rotational speed at which the vibration detection is performed is increased, the Hall sensor detection interval time is shortened as a whole, so that the faster the rotational speed, the relatively smaller the value of Hdn. In this case, as in the first embodiment, only the first vibration detection amount is calculated, so that the detection at the high speed operation can hardly be detected. Therefore, the command rotational speed ω and the reference motor command rotational speed ω * are calculated and the second vibration is calculated. The magnitude of the amount of fluctuation generated by vibration is secured as the detection amount. It can be said that the larger the second vibration detection amount, the larger the rotation speed fluctuation and the greater the vibration (S1008). Note that step S1008 is an example of the motor vibration detection unit.
He = (Hdmax−Hdmin) × (ω / ω *)
He: second vibration detection amount Hdmax: maximum value of detection interval difference due to contents Hdmin: minimum value of detection interval difference due to contents In the present embodiment, He = {17 − (− 16)} × (1000/400) = 82.5.

  Regarding the operation after determining the second vibration detection amount, various methods are conceivable as to how to set vibration countermeasures. For example, there are a method of determining that it is dangerous if a certain threshold is exceeded, and stopping the rotation of the drive motor 1, and a method of not performing further acceleration. Of course, vibration countermeasures may be performed by other methods.

(Third embodiment)
A washing machine according to a third embodiment of the present invention includes the motor driving device according to the first embodiment or the second embodiment. In the following description, the same components as those described in the first embodiment or the second embodiment will be described using the same reference numerals as those in the first embodiment or the second embodiment.

  In the third embodiment, the content put into the container 12 is a laundry cloth, and vibration detection is performed when the container 12 is rotated at a high speed during a dehydration process or the like. This vibration detection can improve the accuracy of detecting abnormal vibration due to the eccentric weight of the laundry. As a result, abnormal vibration can be prevented. In addition, since the shortening of the dehydrating operation time can be expected, it can be expected that the power consumption can be reduced.

  The washing machine may or may not include a drying device that dries laundry.

  In addition, this invention is not limited only to the said 1st-3rd embodiment.

  Further, the present invention may be appropriately combined with the first to third embodiments.

FIG. 1 is a block diagram of a motor drive device according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view of the main part of the drive motor. FIG. 3 is a flowchart of the magnetic pole interval correction time setting operation. FIG. 4 is a graph showing the relationship between the hall sensor detection position and the hall sensor detection interval time. FIG. 5 is a table of detection interval correction times determined by the magnetic pole interval correction time setting operation. FIG. 6 is a flowchart of the vibration detection operation. FIG. 7 is a graph showing the relationship between the Hall sensor detection position and the Hall sensor detection interval time. FIG. 8 is a table of detection times after correction calculated by the magnetic pole interval correction operation. FIG. 9 is a graph of the deviation in detection time after correction calculated by the magnetic pole interval correction operation. FIG. 10 is a flowchart of the magnetic pole interval correction operation for expanding the detected rotation speed range. FIG. 11 is a graph of the magnetic pole detection interval of the magnetic pole interval correction operation for expanding the detection rotation speed range. FIG. 12 is a table showing the corrected detection time calculated by the magnetic pole interval correction operation for expanding the detected rotation speed range. FIG. 13 is a graph of the detection time deviation after correction calculated by the magnetic pole interval correction operation for expanding the detection rotation speed range. FIG. 14 is a graph of the rotational speed fluctuation state for each rotation of the drive motor with respect to the reference rotational speed when the same eccentric weight exists. FIG. 15 is a schematic configuration diagram of a main part of the motor drive device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive motor 2 Magnetic pole detection part 3 Microcomputer 4 Inverter circuit 5 Angle calculating part 6 Rotational speed calculating part 7 Timer 8 RAM
9 ROM
DESCRIPTION OF SYMBOLS 10 Motor output voltage calculating part 11 Position detection part 12 Container 13 Magnet rotor 14 Hall sensor

Claims (9)

A motor that generates rotational driving force;
A container that is attached to the motor and rotates by receiving the rotational driving force of the motor;
A magnetic pole detector for detecting the magnetic pole of the motor;
A specific position detector for detecting a specific position of the magnetic pole of the motor;
A magnetic pole interval time storage unit that stores a magnetic pole interval time that is a time required for the rotation of the magnetic pole interval of the motor and is calculated based on the output of the magnetic pole detection unit;
A magnetic pole interval correction time storage unit for storing the magnetic pole interval correction time for correcting the magnetic pole interval time,
A motor driving device characterized by detecting vibrations of the motor caused by a bias of contents put in the container using the magnetic pole interval time and the magnetic pole interval correction time. The motor drive device according to claim 1,
The magnetic pole interval time storage unit includes a plurality of the magnetic poles measured while the motor is rotated once when the container in a state where the contents are not charged is rotated at a predetermined no-load reference rotational speed. A motor driving device characterized in that an interval time is stored. In the motor drive device according to claim 2,
The magnetic pole interval correction time is a correction value calculated based on the no-load reference rotation speed and the actual rotation speed of the motor. In the motor drive device according to claim 3,
A plurality of magnetic pole interval times are acquired while the motor makes one revolution at the actual rotation number, and a plurality of values are acquired by correcting the magnetic pole interval times with the magnetic pole interval correction time. A motor driving device that detects vibration of the motor based on a difference between a maximum value among the plurality of values and a minimum value among the plurality of values. In the motor drive device according to claim 3,
A plurality of magnetic pole interval times are acquired while the motor makes one revolution at the actual rotation number, and a plurality of values are acquired by correcting the magnetic pole interval times with the magnetic pole interval correction time. The vibration of the motor is detected based on the difference between the maximum value among the plurality of values and the minimum value among the plurality of values and the ratio of the actual rotational speed to the no-load reference rotational speed. A motor drive device characterized by that. The motor drive device according to claim 1,
The motor driving device according to claim 1, wherein the actual rotational speed is a rotational speed at which the contents in the container are stuck inside the container by centrifugal force. The motor drive device according to claim 1,
The motor drive apparatus according to claim 1, wherein the specific position detector is a container specific position detector that detects a position of the specific part of the container.   A washing machine comprising the motor driving device according to claim 1. The washing machine according to claim 8,
A washing machine comprising a drying device for drying the contents charged in the container.

Images