JP2021118637A - Motor driving control device and method for controlling the same - Google Patents

Abstract

To provide a motor driving control device capable of suppressing uneven rotation over the whole of a rotation speed region of a motor, and a method for controlling the same.SOLUTION: A motor driving control device comprises: a control circuit unit which drives a motor including a plurality of position detection elements for detecting a magnetic pole of a rotor and outputs a driving control signal on the basis of a first generation signal or a second generation signal; and a motor driving unit which outputs a sine wave driving signal for driving the motor with a sine wave on the basis of the driving control signal. The control circuit unit comprises a position signal processing circuit. The position signal processing circuit comprises: a first generation circuit which outputs the first generation signal on the basis of a position signal output by each of the plurality of position detection elements; a second generation circuit which outputs a second generation signal on the basis of a position signal output from any one of the plurality of position detection elements; and a selection circuit which outputs the first generation signal when a rotation speed of the motor is faster than or equal to a reference rotation speed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a motor drive control device for driving a motor including a plurality of position detecting elements for detecting the magnetic poles of a rotor, and a control method thereof.

As a control method of the rotation speed of the motor by the motor drive control device, there is a method of inputting a target rotation speed signal from the outside and controlling the rotation speed of the motor so as to correspond to the target rotation speed signal. Examples of the target rotation speed signal include a clock signal, and the rotation speed of the motor is controlled according to the clock signal.

In such a motor drive control device, it is necessary to energize the coils of each phase in synchronization with the position of the rotating rotor. Therefore, in order to control the rotation of the rotor, the drive control device of the motor detects the position of the rotor based on the position signal by the position detection element, and sets a pattern for energizing each phase of the motor accordingly. ..

Patent Document 1 discloses a motor drive control device in which three Hall ICs are arranged as position detection elements in each of the three-phase coils and drive control is performed based on a position signal output from each Hall IC. There is.

Japanese Unexamined Patent Publication No. 2010-22196

However, in the device as described in Patent Document 1 described above, if the motor assembly accuracy and the Hall IC mounting accuracy are low, there is a problem that accurate position detection cannot be performed and rotation unevenness occurs.
For example, if a motor used in an air conditioner or the like causes abnormal rotation, an abnormal noise is generated, and if a motor used in a printer or the like causes uneven rotation, a problem such as printing unevenness occurs. It is necessary to suppress unevenness.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a motor drive control device for suppressing rotation unevenness over the entire rotation speed region of a motor and a control method thereof.

The motor drive control device of the present invention drives a motor including a plurality of position detecting elements for detecting the magnetic poles of the rotor.
A control circuit unit that outputs a drive control signal based on the first generated signal or the second generated signal, and
A motor drive unit that outputs a sine wave drive signal for driving the motor in a sine wave based on the drive control signal.
With
The control circuit unit includes a position signal processing circuit, and the position signal processing circuit is
A first generation circuit that outputs the first generation signal based on the position signals output from each of the plurality of position detection elements, and a first generation circuit.
A second generation circuit that outputs the second generation signal based on the position signal output from any one of the plurality of position detection elements.
When the rotation speed of the motor is equal to or higher than the reference rotation speed, the selection circuit that outputs the first generated signal and the selection circuit.
Have.

In the present invention, when the deviation between the rotation speed of the motor and the target value of the rotation speed of the motor is larger than a predetermined value, the selection circuit preferably outputs the first generated signal.

In the present invention, when the deviation between the rotation speed of the motor and the target value of the rotation speed of the motor is equal to or less than a predetermined value and the rotation speed of the motor is less than the reference rotation speed, the selection circuit is described. It is preferable to output the second generated signal.

The control method of the motor drive control device of the present invention drives a motor including a plurality of position detection elements for detecting the magnetic poles of the rotor.
When the rotation speed of the motor is equal to or higher than the reference rotation speed, a drive control signal is output based on the first generated signal output based on the position signals output from each of the plurality of position detection elements.
Based on the drive control signal, a sine wave drive signal for driving the motor in a sine wave is output.

The present invention can provide a motor drive control device and a control method thereof that suppress rotation unevenness over the entire rotation speed region of the motor.

It is a block diagram which shows the circuit structure of the motor drive control device which concerns on one Embodiment of this invention. It is a figure for demonstrating the principle of this invention. It is a flowchart which shows the switching operation from 3 hole drive to 1 hole drive, and the switching operation from 1 hole drive to 3 hole drive. It is a timing chart explaining the switching of a drive system.

FIG. 1 is a block diagram showing a circuit configuration of a motor drive control device according to an embodiment of the present invention.
The motor drive control device 1 includes a motor drive unit 2 and a control circuit unit 3, and is configured to drive the motor 20. The motor 20 is, for example, a three-phase brushless motor. The motor drive control device 1 drives the motor 20 in a sinusoidal manner by outputting, for example, a sinusoidal drive signal to the motor 20 and periodically passing a sinusoidal drive current through the coil of the motor 20.

The motor drive unit 2 includes an inverter circuit 2a and a predrive circuit 2b.
The inverter circuit 2a outputs a drive signal to the motor 20 based on the output signal output from the predrive circuit 2b, and energizes the coil of the motor 20. The inverter circuit 2a is configured, for example, by arranging a pair of a series circuit of two switching elements provided at both ends of the DC power supply Vcc for each phase (U phase, V phase, W phase) of the coil. ing. In each pair of the two switching elements, the terminals of each phase of the motor 20 are connected to the connection points between the switching elements.
The predrive circuit 2b generates output signals Vuu, Vul, Vvu, Vvl, Vwoo, and Vwl for driving the inverter circuit 2a based on the control by the control circuit unit 3, and outputs the output signals to the inverter circuit 2a. Based on these output signals, the corresponding switching elements of the inverter circuit 2a perform on / off operations, a drive signal is output to the motor 20, and electric power is supplied to each phase of the motor 20.

The control circuit unit 3 is composed of, for example, a microcomputer or the like.
Three position signals (for example, Hall signals) Hu, Hv, Hw, a rotation speed signal Sr, and a target rotation speed signal Sc are input to the control circuit unit 3. The control circuit unit 3 outputs a drive control signal Sd for performing drive control of the motor 20 based on these signals.

The position signals Hu, Hv, and Hw are, for example, three position detection elements (for example, Hall elements) 25u, 25v arranged around the rotor at substantially equal intervals around the rotor in order to detect the magnetic poles of the rotor of the motor 20. , 25w output. The control circuit unit 3 detects the rotational state of the motor 20 by obtaining information such as the rotational position and the rotational speed information of the motor 20 using the position signals Hu, Hv, and Hw.
The rotation speed signal Sr is information corresponding to the rotation speed of the rotor, and is, for example, a signal generated from the FG pattern of the rotor substrate.
The target rotation speed signal Sc is input from the outside of the control circuit unit 3, for example. The target rotation speed signal Sc is information corresponding to a target value of the rotation speed of the motor 20, and is, for example, a clock signal.

The control circuit unit 3 includes a speed control circuit 31, a memory 32, a speed measurement circuit 33, a combination circuit 34, a position signal processing circuit 35 (Hall signal processing circuit), and a sine wave drive circuit 36. Each circuit is a digital circuit.

The speed control circuit 31 compares the actual rotation speed of the motor 20 (rotational speed signal Sr) with the target value of the rotation speed of the motor 20 (target rotation speed signal Sc), and the deviation (deviation) of the rotation speed of the motor 20. ) Is generated and output to the combination circuit 34.
The speed control circuit 31 outputs LD signal = H when the deviation between the rotation speed of the motor 20 and the target value is larger than a predetermined value (for example, 6.25%), and LD signal = H when the deviation is less than or equal to the predetermined value. Output L.

The memory 32 stores a reference rotation speed (for example, 1200 rpm) and various set values used for the operation of the control circuit unit 3. The reference rotation speed will be described later with reference to FIG.

The speed measurement circuit 33 compares the reference rotation speed from the memory 32 with the rotation speed signal Sr, generates a BD signal indicating the magnitude of the speed, and outputs the BD signal to the combination circuit 34. The speed measurement circuit 33 outputs a BD signal = H when the rotation speed of the motor 20 is equal to or higher than the reference rotation speed, and outputs a BD signal = L when the rotation speed of the motor 20 is less than the reference rotation speed. Although the speed measurement circuit is used in this embodiment, the rotation speed may be detected based on the length of the cycle by using the cycle measurement circuit.

The combination circuit 34 generates the selection signal S1 based on the BD signal from the speed measurement circuit 33 and the LD signal from the speed control circuit 31, and outputs the selection signal S1 to the position signal processing circuit 35.
The selection signal S1 is set as shown in Table 1. That is, when the rotation speed of the motor 20 is less than the reference rotation speed (BD signal = L) and the deviation between the rotation speed of the motor 20 and the target value is equal to or less than a predetermined value (LD signal = L), the selection signal. S1 = L, 1-hole drive is executed as described later, and in other cases, selection signal S1 = H, and 3-hole drive is executed.

The position signal processing circuit 35 includes a first generation circuit 35a, a second generation circuit 35b, and a selection circuit 35c.
Three position signals Hu, Hv, and Hw are input to the first generation circuit 35a. The first generation circuit 35a is a three-phase synthesis circuit, which generates a first generation signal (hereinafter, also referred to as a three-phase synthesis signal) P1 based on the three position signals Hu, Hv, and Hw, and is a selection circuit. Output to 35c. The three-phase composite signal P1 is a signal in which the position of the rotor is updated every 60 degrees of the electric angle.
One of the three position signals Hu, Hv, and Hw is input to the second generation circuit 35b. The second generation circuit 35b generates a second generation signal (hereinafter, also referred to as a one-phase generation signal) P2 corresponding to the rotation position of the motor 20 based on one position signal Hu, and outputs the second generation signal P2 to the selection circuit 35c. do. The one-phase generation signal P2 is a signal in which the position of the rotor is updated every 180 degrees of the electric angle. In addition, other position signals Hv and Hw may be input to the second generation circuit 35b instead of the position signal Hu.
The selection circuit 35c outputs one of the three-phase composite signal P1 and the one-phase generation signal P2 as the generation signal S2 based on the selection signal S1. Specifically, the selection circuit 35c outputs the three-phase composite signal P1 as the generation signal S2 when the selection signal S1 = H, and outputs the one-phase generation signal P2 as the generation signal S2 when the selection signal S1 = L. do.

The speed control circuit 31 generates speed command information S3 based on the rotation speed signal Sr and the target rotation speed signal Sc, and outputs the speed command information S3 to the sine wave drive circuit 36.

The sine wave drive circuit 36 generates a drive control signal Sd for driving the motor drive unit 2 based on the generated signal S2 and the speed command information S3, and outputs the drive control signal Sd to the motor drive unit 2.
When the position signal processing circuit 35 outputs the three-phase composite signal P1 as the generation signal S2, the sinusoidal drive circuit 36 drives the drive control signal Sd for performing three-hole drive based on the generation signal S2 and the speed command information S3. Is output, and when the position signal processing circuit 35 outputs the one-phase composite signal P2 as the generation signal S2, the sinusoidal drive circuit 36 is for performing one-hole drive based on the generation signal S2 and the speed command information S3. The drive control signal Sd is output.
In this way, the generated signal S2 output from the position signal processing circuit 35 is switched between the one based on the three position signals Hu, Hv, and Hw and the one based on the one position signal Hu. It is possible to switch between 3-hole drive and 1-hole drive.

The principle of the present invention will be described with reference to FIG.
As described above, in a motor used for a printer or the like, when rotation unevenness occurs, printing unevenness occurs, so it is necessary to suppress such rotation unevenness. As typical rotation unevenness, there are rotation unevenness caused by the rotation nth order component (n is a natural number determined by the number of poles of the motor / 2), rotation unevenness caused by the rotation primary component, and the like.
One of the causes of the rotation unevenness caused by the rotation nth-order component is that variations in the mounting positions and characteristics of the plurality of position detection elements occur. Therefore, when one position detection element is used, the mounting position and the characteristics do not vary. Therefore, as shown in FIG. 2A, the rotation unevenness caused by the rotation nth component is spread over the entire rotation speed. The 1-hole drive is smaller than the 3-hole drive. The difference in rotational unevenness between the 1-hole drive and the 3-hole drive becomes smaller as the rotational speed increases because the rotational stability increases.
One of the causes of the uneven rotation caused by the primary rotation component is that the rotor of the motor is mounted eccentrically. That is, if the air gap between the rotor and the stator is non-uniform, the rotation speed during one rotation of the rotor changes, causing uneven rotation. In the 3-hole drive, the rotation position is detected based on the 3 position detection elements, but in the 1-hole drive, the rotation positions of the remaining 2 position detection elements are calculated based on one position detection element. As described above, in the 3-hole drive, the actual rotation position is detected, whereas in the 1-hole drive, the rotation position is calculated, so that the rotation position is deviated. Therefore, as shown in FIG. 2B, the rotation unevenness caused by the primary rotation component is smaller in the 3-hole drive than in the 1-hole drive over the entire rotation speed.

Next, as shown in FIG. 2 (c), when FIGS. 2 (a) and 2 (b) are combined and the overall rotation unevenness is examined, the 1-hole drive and the 3-hole drive are used at the reference rotation speed shown by the broken line. It can be seen that the curves of uneven rotation intersect. That is, in the rotation speed region lower than the reference rotation speed, the rotation unevenness is smaller in the 1-hole drive, and in the rotation speed region higher than the reference rotation speed, the rotation unevenness is smaller in the 3-hole drive.
In the low rotation speed region, the one-hole drive has a smaller rotation unevenness because, as shown in FIG. 2A, the effect of reducing the rotation unevenness due to the nth-order rotation component is large.
In the high-speed rotation speed region, the rotation unevenness is smaller in the 3-hole drive because the rotation stability is improved.
Therefore, in the present invention, in the rotation speed region lower than the reference rotation speed, 1-hole drive is used, and in the rotation speed region higher than the reference rotation speed, 3-hole drive is used to rotate the entire rotation speed region. Unevenness can be suppressed.

FIG. 3 is a flowchart showing a switching operation from the 3-hole drive, which is the state after the start-up, to the 1-hole drive in which the deviation is equal to or less than a predetermined value, and the switching operation to the 3-hole drive in which the deviation is equal to or higher than the reference rotation speed.
It is assumed that a predetermined time has passed since the motor 20 was started, the motor 20 is driven by 3 holes, and the reference rotation speed is not reached (BD signal = L).
In step S21, in the 3-hole drive, the sine wave drive circuit 36 outputs a drive control signal Sd for performing the 3-hole drive to drive the motor 20 in a sine wave.
In step S22, when the speed control circuit 31 compares the rotation speed signal Sr with the target rotation speed signal Sc and the deviation between the rotation speed of the motor 20 and the target value is equal to or less than a predetermined value (YES), the LD signal = Output L and proceed to step S23.
In step S23, the 3-hole drive is switched to the 1-hole drive. That is, the combinational circuit 34 outputs the selection signal S1 = L to the selection circuit 35c based on the LD signal = L and the BD signal = L, and the selection circuit 35c outputs the generation signal S2 based on the selection signal S1 = L. The one-phase generation signal P2 is output as. As a result, the sine wave drive circuit 36 outputs a drive control signal Sd for performing one-hole drive, and drives the motor 20.
In step S24, the speed measurement circuit 33 compares the reference rotation speed with the rotation speed signal Sr, and if the rotation speed is equal to or higher than the reference rotation speed (YES), outputs BD signal = H and proceeds to step S25. ..
In step S25, the one-hole drive is switched to the three-hole drive. That is, the combinational circuit 34 outputs the selection signal S1 = H to the selection circuit 35c based on the LD signal = L and the BD signal = H, and the selection circuit 35c outputs the generation signal S2 based on the selection signal S1 = H. As a three-phase generation signal P1, the three-phase generation signal P1 is output. As a result, the sine wave drive circuit 36 outputs a drive control signal Sd for driving the three holes, and drives the motor 20.
In step S22, when the deviation between the rotation speed of the motor 20 and the target value is larger than the predetermined value (NO), the speed control circuit 31 repeats the comparison between the rotation speed signal Sr and the target rotation speed signal Sc.
Further, in step S24, when the rotation speed is less than the reference rotation speed (NO), the speed measurement circuit 33 repeats the comparison between the reference rotation speed and the rotation speed signal Sr.

FIG. 4 is a timing chart illustrating switching of the drive system.
In FIG. 4, the time axis, BD signal, LD signal, and drive system are shown in order from the top.
At first, BD signal = L and LD signal = H, and 3-hole drive is performed.
At time t1, when the deviation between the rotation speed of the motor 20 and the target value becomes equal to or less than a predetermined value and the LD signal = L is switched, the one-hole drive is switched.
At time t2, when the rotation speed of the motor becomes equal to or higher than the reference rotation speed, the BD signal = H, and the LD signal = H due to an event such as load fluctuation, the motor is switched to 3-hole drive.
At time t3, when the LD signal = L is switched and the BD signal = H remains, the 3-hole drive is continued.
As described above, the 1-hole drive is performed only when the BD signal = L and the LD signal = L, and the 3-hole drive is performed in other cases.
In other words, when the rotation speed of the motor is less than the reference rotation speed (BD signal = L) and the deviation between the rotation speed of the motor and the target value is less than or equal to a predetermined value (LD signal = L), the second When the generated signal is output and 1-hole drive is performed and at least one of BD signal = H and LD signal = H is satisfied, the first generated signal is output and 3-hole drive is performed.

The present invention is not limited to the above-described embodiment, and various modifications are possible.
For example, the motor is not limited to a three-phase motor, and the number of position detecting elements is not limited to three.
Further, the motor drive control device 1 may be an integrated circuit device in which a part or all thereof is packaged, or may be packaged together with other devices.
Further, a part or all of the processing may be performed by software or by using a hardware circuit.

1 ... motor drive control device, 2 ... motor drive unit, 2a ... inverter circuit, 2b ... predrive circuit, 3 ... control circuit unit, 20 ... motor, 25u, 25v, 25w ... position detection element, 31 ... speed control circuit, 32 ... Memory, 33 ... Speed measurement circuit, 34 ... Combination circuit, 35 ... Position signal processing circuit, 35a ... First generation circuit, 35b ... Second generation circuit, 35c ... Selection circuit, 36 ... Sine wave drive circuit

Claims (4)

A motor drive control device that drives a motor equipped with a plurality of position detection elements for detecting the magnetic poles of the rotor.
A control circuit unit that outputs a drive control signal based on the first generated signal or the second generated signal, and
A motor drive unit that outputs a sine wave drive signal for driving the motor in a sine wave based on the drive control signal.
With
The control circuit unit includes a position signal processing circuit, and the position signal processing circuit is
A first generation circuit that outputs the first generation signal based on the position signals output from each of the plurality of position detection elements, and a first generation circuit.
A second generation circuit that outputs the second generation signal based on the position signal output from any one of the plurality of position detection elements.
When the rotation speed of the motor is equal to or higher than the reference rotation speed, the selection circuit that outputs the first generated signal and the selection circuit.
Have,
Motor drive control device. When the deviation between the rotation speed of the motor and the target value of the rotation speed of the motor is larger than a predetermined value, the selection circuit outputs the first generated signal.
The motor drive control device according to claim 1. When the deviation between the rotation speed of the motor and the target value of the rotation speed of the motor is equal to or less than a predetermined value and the rotation speed of the motor is less than the reference rotation speed, the selection circuit performs the second generation. Output a signal,
The motor drive control device according to claim 1 or 2. A control method for a motor drive control device that drives a motor equipped with a plurality of position detection elements for detecting the magnetic poles of the rotor.
When the rotation speed of the motor is equal to or higher than the reference rotation speed, a drive control signal is output based on the first generated signal output based on the position signals output from each of the plurality of position detection elements.
Based on the drive control signal, a sine wave drive signal for driving the motor in a sine wave is output.
Control method.

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