JP6619382B2 - Motor drive control device and control method of motor drive control device - Google Patents

Description

  The present invention relates to a motor drive control device and a control method of the motor drive control device, and more particularly to a motor drive control device that performs control so that a motor rotates at a target rotation speed and a control method of the motor drive control device.

  For example, a motor used in a color copying machine or the like is strictly required to reduce the rotation flutter (Wow Flutter). For example, in a color copying machine, if there is uneven rotation of the motor, it causes color unevenness during printing.

  In recent years, there is a case where it is necessary to reduce one rotation component or higher harmonic component for rotation unevenness. One rotation component is a periodic unevenness that occurs every time the motor rotates once, and is generated due to the influence of the assembly accuracy of the motor and the like. The harmonic component is a component determined by the number of magnetic poles of the motor, and is generated due to the mounting accuracy of a position detection element such as a Hall element and the influence of magnetization of the magnet.

  For example, in Patent Document 1 below, the rotational position of the motor is detected by a plurality of Hall elements, and a rotational speed signal indicating the rotational speed of the motor is obtained by a frequency dividing circuit. The reference clock generation circuit generates a reference clock according to the rotation speed to be detected, and the error signal generation circuit compares the reference clock and the rotation speed signal to detect a rotation speed deviation, and outputs an error signal. A speed control device for a DC brushless motor is disclosed in which these error signals are synthesized by a signal synthesis circuit to synthesize a speed control signal.

  Patent Document 2 listed below realizes suppression of speed fluctuations of a rotating body and stable driving for a long time, which is used in an image forming apparatus, and reduces “color misregistration” and “pitch unevenness” which are image deterioration factors. The configuration of the speed control device is disclosed. The angular velocity fluctuation of the rotating body is detected by the encoder, and the low frequency speed fluctuation component correction control and the high frequency speed fluctuation component correction control are executed for the stepping motor.

JP 2000-60177 A JP 2008-278620 A

  For example, as described in Patent Document 1, the rotation unevenness caused by the mounting accuracy of a position detection element such as a Hall element can be improved by performing control based on information about one Hall element. There is a possibility. However, in such a case, the rotational speed information obtained from the Hall elements is reduced as compared with the case where control is performed using a plurality of Hall elements, and there is a problem that accuracy is lowered.

  Also, in recent years, as rotation unevenness, rotation unevenness caused by frequency components such as rotation unevenness of one rotation component caused by variations in motor assembly accuracy and rotation unevenness of harmonic components caused by variations in hole mounting accuracy. However, it is necessary to improve as a factor that decreases the accuracy of the rotation speed.

  The present invention has been made to solve such a problem, and can reduce the motor rotation unevenness and the frequency component of the motor rotation unevenness, and can drive the motor with high accuracy. It aims at providing the control method of a control device and a motor drive control device.

  In order to achieve the above object, according to one aspect of the present invention, the motor drive control device drives the motor based on the instruction signal corresponding to the target rotational speed of the motor and the detection signal corresponding to the rotational position of the rotor of the motor. And a motor drive unit that outputs a drive signal to the motor based on the drive control signal output from the control circuit unit. The first drive control signal generated based on the instruction signal and the detection signal until the rotation speed of the motor reaches the speed corresponding to the target rotation speed after the rotation of the motor is compared with the rotation speed of the motor. Is output as a drive control signal, and when the rotational speed of the motor reaches a speed corresponding to the target rotational speed, based on a theoretical value related to the rotational position of the rotor of the motor calculated from the instruction signal. A second drive control signal generated have outputs as a drive control signal.

  Preferably, the control circuit unit outputs the first drive control signal as a drive control signal when the rotation speed of the motor deviates from a speed corresponding to the target rotation speed.

  Preferably, the speed corresponding to the target rotational speed is a speed within a predetermined range including the target rotational speed.

  Preferably, the control circuit unit compares the instruction signal with the rotational speed of the motor and outputs a command signal related to the motor torque, and based on the detection signal, the control circuit unit corresponds to the rotational position of the rotor of the motor. A theoretical value that theoretically corresponds to the rotational position of the rotor of the motor based on the position / rotational speed detection circuit that outputs one rotational speed signal and the instruction signal, and outputs the theoretical value as the second rotational speed signal A value calculating circuit, and a selector that outputs either the first rotation speed signal or the second rotation speed signal according to the comparison result of the speed control circuit, and the first rotation speed signal output from the selector; A drive control signal is output based on one of the second rotation speed signals and the command signal output from the speed control circuit.

  Preferably, the motor is a three-phase motor, the detection signal is a three-phase hall signal corresponding to the position of the magnetic pole of the rotor, and the control circuit unit is obtained by synthesizing the three-phase hall signal. The first drive control signal is generated based on the FG signal, the instruction signal is a signal having a period corresponding to the target rotation speed, and the theoretical value corresponds to the period of the instruction signal and the period during which the motor rotates by a predetermined angle. And the number of pulses of the FG signal to be calculated.

  According to another aspect of the present invention, the control method of the motor drive control device drives the motor based on the instruction signal corresponding to the target rotational speed of the motor and the detection signal corresponding to the rotational position of the rotor of the motor. A control method for a motor drive control device that outputs a drive control signal of the motor and outputs a drive signal to the motor based on the drive control signal, the comparison step comparing the instruction signal and the rotation speed of the motor, and the motor drive A first output step of outputting, as a drive control signal, a first drive control signal generated based on the instruction signal and the detection signal until the rotation speed of the motor reaches a speed corresponding to the target rotation speed after When the rotational speed of the motor reaches a speed corresponding to the target rotational speed, it is generated based on a theoretical value related to the rotational position of the rotor of the motor calculated from the instruction signal The second drive control signal and a second output step of outputting as the drive control signal.

  According to these inventions, it is possible to reduce motor rotation unevenness and frequency components of motor rotation unevenness, and to provide a motor drive control device and a motor drive control device control method capable of driving a motor with high accuracy. be able to.

FIG. 1 is a diagram showing a circuit configuration of a motor drive control device according to one embodiment of the present invention. It is a block diagram which shows the structure of the control circuit part in 1st Embodiment. It is a figure explaining the relationship between a detection signal and a 1st rotation speed signal, and the relationship between a clock signal and a 2nd rotation speed signal. It is a flowchart which shows operation | movement of a motor drive control apparatus.

  Hereinafter, a motor drive control device according to an embodiment of the present invention will be described.

  [Embodiment]

  FIG. 1 is a diagram showing a circuit configuration of a motor drive control device 1 according to one embodiment of the present invention.

  As shown in FIG. 1, the motor drive control device 1 is configured to drive a brushless motor 20 (hereinafter simply referred to as a motor 20) by, for example, sinusoidal drive. In the present embodiment, the motor 20 is, for example, a three-phase brushless motor. The motor drive control device 1 rotates the motor 20 by outputting a sine wave drive signal to the motor 20 and periodically passing a sine wave drive current through the armature coils Lu, Lv, Lw of the motor 20.

  The motor drive control device 1 includes a motor drive unit 2 having an inverter circuit 2a and a predrive circuit 2b, and a control circuit unit 3. The components of the motor drive control device 1 shown in FIG. 1 are a part of the whole, and the motor drive control device 1 has other components in addition to those shown in FIG. You may do it. Although details will be described later, the control circuit unit 3 determines whether the motor 20 is based on a clock signal (an example of an instruction signal) Sc corresponding to the target rotational speed of the motor 20 and a detection signal Sr corresponding to the rotational position of the rotor of the motor 20. A drive control signal for driving 20 is output. The motor drive unit 2 outputs a drive signal to the motor 20 based on the drive control signal Sd output from the control circuit unit 3. Then, the control circuit unit 3 compares the clock signal Sc with the rotational speed of the motor 20, and after the driving of the motor 20 is started, until the rotational speed of the motor 20 reaches a speed corresponding to the target rotational speed, The first drive control signal generated based on the signal Sc and the detection signal Sr is output as the drive control signal Sd. When the rotational speed of the motor 20 reaches a speed corresponding to the target rotational speed, the first drive control signal is calculated from the clock signal Sc. The second drive control signal generated based on the theoretical value related to the rotational position of the rotor of the motor 20 is output as the drive control signal Sd.

  In the present embodiment, the motor drive control device 1 is an integrated circuit device IC that is entirely packaged. A part of the motor drive control device 1 may be packaged as one integrated circuit device, or all or part of the motor drive control device 1 is packaged together with other devices as one integrated circuit device. A circuit device may be configured.

  The inverter circuit 2a and the predrive circuit 2b constitute a motor drive unit 2. The inverter circuit 2a outputs a drive signal to the motor 20 based on the output signal output from the pre-drive circuit 2b, and energizes the armature coils Lu, Lv, Lw included in the motor 20. In the inverter circuit 2a, for example, a pair of series circuits of two switch elements provided at both ends of the DC power supply Vcc is connected to each phase (U phase, V phase, W phase) of the armature coils Lu, Lv, Lw. Are arranged and configured. In each pair of two switch elements, a terminal of each phase of the motor 20 is connected to a connection point between the switch elements.

  The pre-drive circuit 2b generates an output signal for driving the inverter circuit 2a based on the control by the control circuit unit 3, and outputs the output signal to the inverter circuit 2a. As output signals, for example, six types of signals Vuu, Vul, Vvu, Vvl, Vwu, Vwl corresponding to each switch element of the inverter circuit 2a are output. When these output signals are input to the inverter circuit 2a, the switch elements corresponding to the respective signals are turned on and off, and a drive signal is output to the motor 20 to supply power to each phase of the motor 20. (Not shown).

  A detection signal Sr corresponding to the rotational position of the rotor of the motor 20 is input from the motor 20 to the control circuit unit 3. The detection signal Sr is, for example, three hall signals Hu, Hv, and Hw. The hall signals Hu, Hv, Hw are output signals of, for example, three hall (HALL) elements 25u, 25v, 25w arranged in the motor 20. The control circuit unit 3 detects the rotational state of the motor 20 by obtaining information such as the rotational position of the motor 20 and rotational speed information (FG signal, etc.) using the Hall signals Hu, Hv, Hw. Control the drive.

  The three Hall elements 25u, 25v, and 25w (hereinafter, collectively referred to as the Hall element 25) are, for example, substantially equal intervals (at intervals of 120 degrees with adjacent ones) of the rotor of the motor 20. It is arranged around. Hall elements 25u, 25v, and 25w detect the magnetic poles of the rotor and output Hall signals Hu, Hv, and Hw, respectively.

  The control circuit unit 3 is configured such that other signals corresponding to the rotational position of the rotor of the motor 20 are input as the detection signal Sr instead of the hall signals Hu, Hv, Hw. Also good. For example, an encoder or a resolver may be provided so that the detection signal is input.

  A clock signal (an example of an instruction signal) Sc is input to the control circuit unit 3. The clock signal Sc is input from the outside of the control circuit unit 3, for example. The clock signal Sc is a signal having a period corresponding to the target rotational speed of the motor 20, for example. In other words, the clock signal Sc is an instruction signal that designates the target rotational speed of the motor 20.

  The control circuit unit 3 is constituted by, for example, a microcomputer. The control circuit unit 3 outputs a drive control signal Sd for driving the motor 20 to the pre-drive circuit 2b based on the clock signal Sc and the detection signal Sr. The control circuit unit 3 controls the rotation of the motor 20 by outputting the drive control signal Sd to the motor drive unit 2 and controlling the motor drive unit 2. The motor drive unit 2 drives the motor 20 by outputting a sine wave drive signal to the motor 20 based on the drive control signal Sd output from the control circuit unit 3.

  [Description of Control Circuit Section 3]

  FIG. 2 is a block diagram illustrating a configuration of the control circuit unit 3 according to the first embodiment.

  As shown in FIG. 2, the control circuit unit 3 includes a speed control circuit 31 and a sine wave drive circuit 35. The control circuit unit 3 includes a position / rotation speed detection circuit 32, a theoretical value calculation circuit 33, and a selector (selection circuit) 34. Each of these circuits is a digital circuit. In FIG. 2, transmission / reception of signals and information between the circuits is related to the description related to generation of the drive control signal Sd. As will be described in detail below, in the control circuit unit 3, the speed control wheel 31 compares the clock signal (an example of the instruction signal) Sc with the rotation speed of the motor 20 and compares the torque command signal (related to the torque of the motor 20). An example of a command signal) When S1 is output, the position / rotation speed detection circuit 32 outputs a first rotation speed signal S2 corresponding to the rotation position of the rotor of the motor 20 based on the detection signal Sr, and calculates a theoretical value. The circuit 33 calculates a theoretical value theoretically corresponding to the rotational position of the rotor of the motor 20 based on the clock signal Sc, and outputs the theoretical value as the second rotational speed signal S3. Then, the selector 34 selects one of the first rotation speed signal S2 and the second rotation speed signal S3 according to the rotation speed determination signal (an example of the comparison result of the speed control circuit) output from the speed control circuit 31. The sine wave drive circuit 35 outputs the first rotation speed signal S2 and the second rotation speed signal S3 output from the selector 34 and the torque command signal S1 output from the speed control circuit 31. Based on this, the drive control signal Sd is output.

  The speed control circuit 31 receives detection signals Sr (Hall signals Hu, Hv, Hw). The speed control circuit 31 outputs a torque command signal (an example of a command signal) S1 related to the rotation speed of the motor 20 based on the clock signal Sc and the detection signal Sr. Specifically, for example, the speed control circuit 31 detects the rotational speed of the motor 20 based on the input detection signal Sr. Then, the speed control circuit 31 generates the torque command signal S1 so that the rotation speed of the motor 20 detected based on the detection signal Sr becomes a target rotation speed corresponding to the clock signal Sc. In other words, the speed control circuit 31 compares the target rotational speed corresponding to the clock signal Sc with the rotational speed of the motor 20, and outputs the torque command signal S1. At this time, the speed control circuit 31 may perform advance angle control and output the torque command signal S1.

  Further, the speed control circuit 31 compares the target rotational speed corresponding to the clock signal Sc with the rotational speed of the motor 20, and outputs a rotational speed determination signal (an example of a comparison result) S4. The rotation speed determination signal S4 is input to the selector 34. Details of the rotation speed determination signal S4 will be described later.

  A torque command signal S1 and a base signal S5 input from the selector 34 are input to the sine wave drive circuit 35. The sine wave drive circuit 35 generates a drive control signal Sd for driving the motor drive unit 2 based on the torque command signal S1 and the base signal S5. By outputting the drive control signal Sd to the motor drive unit 2, a sine wave drive signal is output from the motor drive unit 2 to the motor 20, and the motor 20 is driven. That is, the speed control circuit 31 and the sine wave drive circuit 35 generate a drive control signal Sd based on the clock signal Sc and output it to the motor drive unit 2.

  The selector 34 receives a first rotation speed signal S2 output from the position / rotation speed detection circuit 32 and a second rotation speed signal (an example of a theoretical value) S3 output from the theoretical value calculation circuit 33. . The selector 34 outputs either the first rotation speed signal S2 or the second rotation speed signal S3 as the base signal S5 in response to the rotation speed determination signal S4. The output base signal S5 is input to the sine wave drive circuit 35.

  FIG. 3 is a diagram illustrating the relationship between the detection signal Sr and the first rotation speed signal S2 and the relationship between the clock signal Sc and the second rotation speed signal S3. As will be described in detail below, the control circuit unit 3 generates the first drive control signal based on the FG signal (three-phase combined signal) obtained by combining the three-phase hall signals, and the clock signal Sc The theoretical value is calculated based on the cycle of the clock signal Sc and the number of pulses of the FG signal corresponding to the period during which the motor 20 rotates by a predetermined angle.

  As shown in FIG. 2, the detection signal Sr is input to the position / rotation speed detection circuit 32. As shown in FIG. 3, the position / rotation speed detection circuit 32 synthesizes the input detection signal Sr, that is, the three-phase hall signals Hu, Hv, and Hw to generate an FG signal (three-phase synthesis signal). To do. Then, the first rotation speed signal S2 is generated based on the generated FG signal. Specifically, for example, the first rotation speed signal S2 is generated by dividing the cycle of the FG signal by a predetermined number. The generated first rotation speed signal S2 is input to the selector 34.

  The theoretical value calculation circuit 33 receives the clock signal Sc. As shown in FIG. 3, the theoretical value calculation circuit 33 calculates a theoretical value related to the rotational position of the rotor of the motor based on the clock signal Sc. Then, the calculated theoretical value is output as the second rotation speed signal S3. The output second rotation speed signal S3 is input to the selector 34.

  Here, the theoretical value is calculated based on the cycle of the clock signal Sc and the number of pulses of the FG signal corresponding to the period during which the motor 20 rotates by a predetermined angle, as shown below. The frequency of the clock signal Sc is 400 (Hz), the number of pulses of the FG signal per rotation of the rotor = 45 (pulse / rev), and the motor 20 is a 10-pole motor (N pole and S pole are 5). Assume the case).

  At this time, the cycle of the clock signal Sc is as follows.

  1/400 (Hz) = 2.5 (ms)

  Further, the period of the electrical angle of 360 degrees, that is, the period of each Hall signal Hu, Hv, Hw is based on the period of the clock signal Sc, the number of pulses of the FG signal per one rotation of the rotor, and the number of magnetic poles of the motor 20. Is required. Specifically, the following equation is obtained.

  2.5 (ms) * 45 (pulse / rev) / 5 (set) = 22.5 (ms)

  Then, since the half cycle of the FG signal is 1/6 of the cycle of the Hall signal, the following equation is obtained.

  22.5 (ms) /6=3.75 (ms)

  The theoretical value is obtained by dividing the half cycle of the FG signal by the resolution X (ms) of the base signal in the same manner as the first rotation speed signal S2, and is expressed by the following equation.

  3.75 (ms) / X (ms) = (theoretical value (ms))

  When the target rotational speed corresponding to the clock signal Sc matches the rotational speed of the motor 20, the theoretical value obtained based on the clock signal Sc in this way theoretically corresponds to the rotational position of the rotor of the motor 20. It can be said that.

  The selector 34 uses one of the first rotation speed signal S2 input from the position / rotation speed detection circuit 32 and the second rotation speed signal S3 input from the theoretical value calculation circuit 33 in this way as a rotation speed determination signal. The selection is made based on S4, and the selected signal is output as the base signal S5. In other words, the speed control circuit 31 outputs either the rotation speed determination signal S4, and thereby outputs either the first rotation speed signal S2 or the second rotation speed signal S3 as the base signal S5 input to the sine wave drive circuit 35. Switch whether to use.

  In the present embodiment, the speed control circuit 31 outputs the rotational speed determination signal S4 so that the rotational speed of the motor 20 detected based on the detection signal Sr corresponds to the target rotational speed corresponding to the clock signal Sc. The base signal S5 is switched according to whether the speed is set. Specifically, when the rotational speed of the motor 20 is not a speed corresponding to the target rotational speed, the selector 34 outputs the first rotational speed signal S2 as the base signal S5, and the rotational speed of the motor 20 becomes the target rotational speed. When the speed is the corresponding speed, the second rotation speed signal S3 is output as the base signal S5. In other words, in the present embodiment, the speed control circuit 31 rotates when the rotational speed is within a predetermined range including the target rotational speed (hereinafter, sometimes simply within the predetermined speed range). It is determined that the speed is a speed corresponding to the target rotation speed, and a rotation speed determination signal S4 is output as a determination result. The selector 34 outputs the first rotational speed signal S2 as the base signal S5 when the rotational speed of the motor 20 is not within the predetermined speed range, and the base signal when the rotational speed of the motor 20 is within the predetermined speed range. The second rotation speed signal S3 is output as S5. The predetermined speed range can be, for example, a range of several percent above and below the target rotation speed, but is not limited thereto.

  As described below, the control method of the motor drive control device 1 according to the present embodiment includes a comparison step for comparing a clock signal (an example of an instruction signal) Sc and the rotation speed of the motor 20, and a first drive control signal. Is output as the drive control signal Sd, and a second output step is output that outputs the second drive control signal as the drive control signal Sd.

  In the present embodiment, the control circuit unit 3 outputs the drive control signal Sd as follows. That is, the control circuit unit 3 (speed control circuit 31) compares the clock signal Sc with the rotation speed of the motor (comparison step). The control circuit unit 3 (sinusoidal drive circuit 35) is based on the clock signal Sc and the detection signal Sr until the rotational speed of the motor 20 reaches a speed corresponding to the target rotational speed after the driving of the motor 20 is started. The first drive control signal generated in this way is output as the drive control signal Sd (first output step). Thereafter, when the rotational speed of the motor 20 reaches a speed corresponding to the target rotational speed, the control circuit unit 3 (the sine wave drive circuit 35) sets the theoretical value related to the rotational position of the rotor of the motor 20 calculated from the clock signal Sc. The second drive control signal generated based on the output is output as the drive control signal Sd (second output step). Such an operation will be specifically described below.

  FIG. 4 is a flowchart showing the operation of the motor drive control device 1.

  As shown in FIG. 4, when the motor 20 is not driven in step S11, when the clock signal Sc is input, the control circuit unit 3 detects it.

  In step S <b> 12, the control circuit unit 3 starts the motor 20. At this time, the speed control circuit 31 outputs the rotation speed determination signal S4, whereby the selector 34 outputs the first rotation speed signal S2 as the base signal S5. The sine wave drive circuit 35 generates and outputs a drive control signal Sd based on the first rotation speed signal S2 and the torque command signal S1 (an example of a first output step). The drive control signal Sd generated at this time is a first drive control signal generated based on the clock signal Sc and the detection signal Sr. By outputting the torque command signal S1 from the speed control circuit 31, control is performed so that the rotational speed of the motor 20 becomes the target rotational speed. The motor 20 is driven based on the clock signal Sc and the detection signal Sr (normal drive).

  In step S13, the control circuit unit 3 detects whether or not the input of the clock signal Sc is stopped. If it is not detected that the input of the clock signal Sc has been stopped, the process proceeds to step S14. When it is detected that the input of the clock signal Sc is stopped, the process proceeds to step S18.

  In step S14, the speed control circuit 31 determines whether or not the rotation speed is within a predetermined speed range (within a predetermined value) (an example of a comparison step). If the rotation speed is within the predetermined speed range, the process proceeds to step S15. If the rotation speed is not within the predetermined speed range, the processes after step S12 are repeated.

  When the rotational speed reaches the predetermined speed range after the driving of the motor 20 is started (YES in step S14), the driving using the theoretical value is performed in step S15 (theoretical value driving). That is, if the rotational speed is within the predetermined speed range, the speed control circuit 31 outputs the rotational speed determination signal S4, whereby the selector 34 outputs the second rotational speed signal S3 as the base signal S5. The sine wave drive circuit 35 generates and outputs a drive control signal Sd based on the second rotational speed signal S3 and the torque command signal S1, which are theoretical values calculated based on the clock signal Sc (second output). Example of step). The drive control signal Sd generated at this time is a second drive control signal generated based on a theoretical value related to the rotational position of the rotor of the motor 20 calculated from the clock signal Sc.

  Even in the case where the theoretical value driving is performed in step S16, the speed control circuit 31 determines whether or not the rotation speed is within a predetermined speed range (within a predetermined value) as in step S14. If the rotation speed is not within the predetermined speed range, the process proceeds to step S12. That is, when the load is applied or the target rotation speed is changed and the rotation speed is out of the predetermined speed range, the process returns to the normal drive (step S12). When returning to the normal drive, the selector 34 outputs the first rotation speed signal S2 as the base signal S5, and the sine wave drive circuit 35 outputs the first drive control signal as the drive control signal Sd. On the other hand, if the rotation speed is within the predetermined speed range, the process proceeds to step S17.

  In step S17, as in step S13, the control circuit unit 3 detects whether or not the input of the clock signal Sc is stopped. If it is not detected that the input of the clock signal Sc has been stopped, the processing from step S15 is repeated. When it is detected that the input of the clock signal Sc is stopped, the process proceeds to step S18.

  In step S18, the control circuit unit 3 starts a free-run stop. That is, the torque control signal 31 is output from the speed control circuit 31 and the drive control signal Sd is output, so that all phases of the motor 20 are turned off. As a result, the motor 20 stops in a free run. In addition, when stopping, control which performs a short brake etc. may be performed.

  As described above, as shown in FIG. 3, the first rotation speed signal S2 is generated at a timing based on the detection signal Sr, and the first rotation speed signal S2 includes, for example, the Hall element 25 There may be variations due to mounting accuracy and variations due to uneven magnetization of the magnet of the motor 20. If there is a variation in the first rotation speed signal S2, the drive control signal Sd that is output based on the variation is also affected, resulting in uneven rotation of the motor 20. As a characteristic of the rotation unevenness of the motor 20 for each frequency component, the variation due to the assembly accuracy of the motor 20 and the magnet magnetization unevenness becomes unevenness of one rotation component periodically generated every time the motor 20 makes one rotation. The variation due to the mounting accuracy is a harmonic component unevenness periodically generated by the number of magnetic pole sets during one rotation of the motor 20 (for example, when there are five magnetic pole sets, W5 component unevenness).

  On the other hand, in the present embodiment, when the rotational speed of the motor 20 is within a predetermined speed range, the theoretical value (based on the clock signal Sc) as the base signal S5 used in the sine wave drive circuit 35 ( A second rotational speed signal S3) is used. The theoretical value calculated based on the clock signal Sc does not include variation in assembly accuracy of the motor 20, variation due to uneven magnetization of the magnet of the motor 20, variation due to mounting accuracy of the Hall element 25, and the like. Therefore, by driving the motor 20 with the drive control signal Sd output based on the second rotation speed signal S3, the above-described variation due to the assembly accuracy of the motor 20 of the motor 20 and uneven magnetization of the magnet is a factor. The rotation unevenness frequency component (one rotation component) and the rotation unevenness frequency component (harmonic component) caused by variations due to the mounting accuracy of the Hall element 25 can be suppressed.

  Until the rotational speed of the motor 20 falls within the predetermined speed range, normal driving is performed using the base signal S5 based on the detection signal Sr. Therefore, even when there is a large difference between the target rotational speed and the actual rotational speed, such as at the time of startup, control is performed so as to appropriately rotate at the target rotational speed. Since the three-phase hall signals Hu, Hv, and Hw can be used as the detection signal Sr, the motor 20 can be driven with high accuracy according to the rotational position of the motor 20.

  When the rotational speed of the motor 20 deviates from the speed corresponding to the target rotational speed, the control circuit unit 3 outputs the first drive control signal as the drive control signal Sd. That is, once the rotational speed of the motor 20 is within the predetermined speed range and the theoretical value driving is performed, the base signal is set so that the normal driving is performed when the rotational speed of the motor 20 deviates from the predetermined speed range thereafter. S5 is switched. Then, the selector 34 outputs the first rotation speed signal S2 as the base signal S5, and the sine wave drive circuit 35 outputs the clock signal Sc and the detection signal until the rotation speed of the motor 20 reaches a speed corresponding to the target rotation speed. The first drive control signal generated based on Sr is output as the drive control signal Sd. Therefore, for example, when the theoretical value driving is performed, even if the load fluctuation due to disturbance occurs and the rotation speed of the motor 20 changes greatly, the first rotation corresponding to the actual rotation position of the motor 20 is achieved. Based on the speed signal S2, control is performed so as to rotate at a target rotational speed with high accuracy.

  Since the second rotation speed signal S3 can be calculated as a theoretical value, the resolution of the base signal S5 used for sine wave driving or the like can be changed, or the configuration of the motor drive control device 1 can be used to drive a motor or the like having a different number of magnetic poles. It can be easily diverted. The theoretical value calculation circuit 33 can be realized by various methods such as realization by a microcomputer, realization by an IC, and realization by software processing. Therefore, the versatility of the motor drive control device 1 can be improved.

  When the base signal S5 is output, it is not necessary to perform correction processing by using a correction value or providing a circuit for detecting rotation unevenness. Therefore, it is not necessary to store correction values required for such correction processing in the motor drive control device 1 or to provide a new detection circuit or the like, and to simplify the configuration of the motor drive control device 1. Can do.

  [Others]

  The control circuit unit is not limited to the circuit configuration as described above. Various circuit configurations configured to meet the objects of the present invention can be applied.

  The above flowchart is a specific example, and is not limited to this flowchart. For example, another process may be inserted between the steps, or the processes may be parallelized.

  The number of phases of the motor driven by the motor drive control device of the above-described embodiment is not limited to three phases. Further, the number of Hall elements is not limited to three.

  The method for detecting the rotational speed of the motor is not particularly limited. For example, the rotational speed may be detected using the back electromotive force of the motor without using the Hall element.

  The motor driving method is not limited to the sine wave driving method. For example, the present invention can be applied to a rectangular wave driving method, a trapezoidal wave, or a driving method in which special modulation is applied to a sine wave.

  Part or all of the processing in the above-described embodiment may be performed by software or may be performed using a hardware circuit. That is, each component of the motor drive control device may be configured such that at least a part thereof is realized by software processing instead of hardware processing.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Motor drive control apparatus 2 Motor drive part 3 Control circuit part 20 Motor 25 (25u, 25v, 25w) Hall element 31 Speed control circuit 32 Position / rotation speed detection circuit 33 Theoretical value calculation circuit 34 Selector 35 Sine wave drive circuit S1 Torque Command signal (example of command signal)
S2 First rotation speed signal S3 Second rotation speed signal (an example of theoretical value)
S4 Rotational speed determination signal (example of comparison result)
S5 Base signal (first rotation speed signal or second rotation speed signal)
Sc clock signal (an example of an instruction signal corresponding to the target rotational speed)
Sd drive control signal Sr detection signal Hu, Hv, Hw Hall signal

Claims (6)

A control circuit unit that outputs a drive control signal for driving the motor based on an instruction signal corresponding to a target rotational speed of the motor and a detection signal corresponding to the rotational position of the rotor of the motor;
A motor drive unit that outputs a drive signal to the motor based on the drive control signal output from the control circuit unit;
The control circuit unit is
Compare the instruction signal and the rotation speed of the motor,
The first drive control signal generated based on the instruction signal and the detection signal until the rotational speed of the motor reaches a speed corresponding to the target rotational speed after the driving of the motor is started is the drive control. Output as a signal,
When the rotational speed of the motor reaches a speed corresponding to the target rotational speed, a second drive control signal generated based on a theoretical value related to the rotational position of the rotor of the motor calculated from the instruction signal is generated as the drive control signal. Output as
The instruction signal is a signal having a period corresponding to the target rotation speed,
The motor drive control device , wherein the theoretical value is calculated based on a cycle of the instruction signal and a pulse number of an FG signal corresponding to a period during which the motor rotates by a predetermined angle .   2. The motor drive control device according to claim 1, wherein the control circuit unit outputs the first drive control signal as the drive control signal when a rotation speed of the motor deviates from a speed corresponding to the target rotation speed. .   The motor drive control device according to claim 1, wherein the speed corresponding to the target rotational speed is a speed within a predetermined range including the target rotational speed. The control circuit unit is
A speed control circuit that compares the instruction signal with the rotation speed of the motor and outputs a command signal related to the torque of the motor;
A position / rotation speed detection circuit for outputting a first rotation speed signal corresponding to the rotation position of the rotor of the motor based on the detection signal;
Based on the instruction signal, the theoretical value that theoretically corresponds to the rotational position of the rotor of the motor, and a theoretical value calculation circuit that outputs the theoretical value as a second rotational speed signal;
A selector that outputs one of the first rotation speed signal and the second rotation speed signal according to a comparison result of the speed control circuit;
Outputting the drive control signal based on one of the first rotation speed signal and the second rotation speed signal output from the selector and the command signal output from the speed control circuit; The motor drive control apparatus of any one of Claim 1 to 3. The motor is a three-phase motor,
The detection signal is a three-phase Hall signal corresponding to the position of the magnetic pole of the rotor,
Wherein the control circuit unit that generates the first drive control signal based on the FG signal obtained by synthesizing the Hall signal of the 3-phase motor according to any one of claims 1 4 Drive control device. Based on the instruction signal corresponding to the target rotational speed of the motor and the detection signal corresponding to the rotational position of the rotor of the motor, a drive control signal for driving the motor is output, and based on the drive control signal A control method of a motor drive control device for outputting a drive signal to a motor,
A comparison step of comparing the instruction signal and the rotational speed of the motor;
The first drive control signal generated based on the instruction signal and the detection signal until the rotational speed of the motor reaches a speed corresponding to the target rotational speed after the driving of the motor is started is the drive control A first output step for outputting as a signal;
When the rotational speed of the motor reaches a speed corresponding to the target rotational speed, a second drive control signal generated based on a theoretical value relating to the rotational position of the rotor of the motor calculated from the instruction signal is generated as the drive control signal. a second output step of outputting seen contains as,
The instruction signal is a signal having a period corresponding to the target rotation speed,
The method of controlling a motor drive control device, wherein the theoretical value is calculated based on a cycle of the instruction signal and a pulse number of an FG signal corresponding to a period during which the motor rotates by a predetermined angle .

Images