Motor control method

Abstract

To provide a control method of a motor capable of suppressing malfunction by controlling a rotation direction of the motor by switching between a normal rotation direction and a reverse rotation direction with a high degree of freedom.SOLUTION: With an exemplary method of controlling a motor includes the steps of: driving the motor in a forward rotation direction at rotation speed corresponding to a duty cycle range of a first control signal that is a pulse width modulation (PWM) signal; and driving the motor in a reverse rotation direction corresponding to the rotation direction and the rotation speed corresponding to the motor that is not rotating when second control signal is received that is a pulse width modulation (PWM) signal of a different frequency from the first control signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a motor. [Background technology]

[0002] For example, in the washing machine described in Patent Document 1, the microcomputer sequentially sends PWM control signals from a duty of 5% to a duty of 20% in 5% increments to the inverter main circuit to energize the stator coil, and alternately drives the brushless motor in forward and reverse rotation to rotate the agitator forward and reverse to perform the washing operation, and when switching between forward and reverse rotation drives, it sends a PWM control signal with a duty of 5% to the motor to apply reverse braking.

[0003] In Patent Document 1, the PWM control signal for driving the motor in the forward and reverse directions and the PWM control signal for braking the motor in the reverse direction both have a duty of 5%. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 08-009681 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the motor control method described in Patent Document 1, the 5% duty PWM control signal that drives the motor to rotate and the 5% duty PWM control signal that applies reverse control both have a 5% duty, which raises concerns about malfunction and reduces the degree of freedom in controlling the motor to rotate.

[0006] An object of the present invention is to provide a motor control method that can control the rotation direction of a motor by switching it between forward and reverse rotation directions with a high degree of freedom, thereby suppressing malfunctions. [Means for solving the problem]

[0007] An exemplary motor control method of the present invention drives a motor in a forward rotation direction at a rotation speed corresponding to a duty cycle range of a first control signal, which is a pulse width modulation (PWM) signal; when a second control signal, which is a pulse width modulation (PWM) signal with a different frequency from the first control signal, is received, the motor's rotation direction and rotation speed correspond to the motor not rotating, and the motor is driven in a reverse rotation direction. [Effects of the Invention]

[0008] According to the exemplary embodiment of the present invention, it is possible to provide a motor control method that can control the rotation direction of a motor by switching it between forward and reverse rotation directions with a high degree of freedom, thereby suppressing malfunctions. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of an example of a motor control method according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram illustrating a first control signal according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

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

[0011] Fig. 1 is a schematic diagram of the overall configuration of an example of a motor control method according to an embodiment of the present invention, Fig. 2 is a schematic diagram illustrating a first control signal according to an embodiment of the present invention, and Fig. 3 is a schematic diagram illustrating a first control signal according to an embodiment of the present invention. The motor control method, or a corresponding motor control device or motor control system, includes a control unit 1, a drive unit 2, and a motor 3.

[0012] A first control signal, which is a pulse width modulation (PWM) signal, and a second control signal, which is also a pulse width modulation (PWM) signal, are transmitted from the control unit 1 to the drive unit 2, and the drive unit 2 drives the motor 3 based on the received first control signal and second control signal.

[0013] Here, the first control signal and the second control signal have different frequencies. For example, the frequency of the first control signal may be 10 kHz to 30 kHz, and the frequency of the second control signal may be 8 Hz to 12 Hz.

[0014] As shown in Fig. 2, the driver 2 drives the motor 3 in the forward direction at a rotation speed corresponding to the duty cycle range of the first control signal. Here, the horizontal axis of Fig. 2 represents the duty cycle range (unit: %) of the first control signal, and the vertical axis represents the rotation speed (unit: RPM) of the motor 3 in the forward direction.

[0015] Here, since the duty cycle range of 0% corresponds to a rotation speed of 0% in the forward rotation direction of motor 3, it becomes easy to control the rotation speed of motor 3 in the forward rotation direction to be low, and it becomes easy to control the rotation direction of motor 3 by switching between the forward rotation direction and the reverse rotation direction.

[0016] When the rotation direction and rotation speed of the motor 3 correspond to the motor 3 not rotating and the second control signal is received, the motor 3 is driven in the reverse rotation direction.

[0017] In this way, since the frequency of the second control signal that controls the rotation direction of motor 3 in the reverse direction is different from the frequency of the first control signal that controls the rotation of motor 3 in the forward direction, the rotation direction of the motor can be switched between the forward and reverse directions with a high degree of freedom, thereby suppressing malfunctions.

[0018] Here, since the first control signal and the second control signal are both pulse width modulation (PWM) signals, they can be transmitted from the control unit 1 to the drive unit 2 using a common transmission path. When a lead wire is used as the transmission path, the first control signal and the second control signal can be transmitted from the control unit 1 to the drive unit 2 using a common lead wire, so there is no need to provide a lead wire for transmitting the second control signal separately from the lead wire for transmitting the first control signal.

[0019] When the motor 3 is driven in the forward rotation direction and receives the second control signal, the motor 3 is driven in the reverse rotation direction. Here, "the motor 3 is driven in the reverse rotation direction" means that the rotation speed of the motor 3 in the forward rotation direction decreases, and also includes the case where the rotation direction and rotation speed of the motor 3 correspond to the state where the motor 3 is not rotating, and then the motor 3 rotates in the reverse rotation direction.

[0020] By doing this, the rotation direction and rotation speed of the motor 3 can be controlled with a high degree of freedom between forward and reverse rotation directions, not only when the motor 3 is not rotating, but also when the motor 3 is driven in the forward rotation direction, thereby suppressing malfunctions.

[0021] When the rotation direction and rotation speed of the motor 3 correspond to the motor not rotating or when the motor 3 is driven in the reverse rotation direction, the duty cycle range of the received first control signal is greater than 0% and less than 100%. In other words, in the above-mentioned state, the first control signal having a duty cycle range of 0% and the first control signal having a duty cycle range of 100% are not received by the driver 2. Here, "not being received by the driver 2" includes the case where the first control signal is received by the driver 2 but not used to drive or control the motor 3, and the case where the control unit 1 does not send the first control signal to the driver 2.

[0022] This prevents the driver 2 from mistakenly recognizing that it has received the second control signal, even though it has received the first control signal to drive the motor 3 in the forward rotation direction, and thus performing erroneous control. It is difficult to clearly identify the frequency of a pulse-width modulation (PWM) signal whose duty cycle range is 0% or 100%. Therefore, preventing the driver 2 from receiving the first control signal whose duty cycle range is 0% or 100% in the above-described state contributes to preventing malfunction.

[0023] When the rotation direction and rotation speed of the motor 3 correspond to the motor 3 not rotating or the motor 3 being driven in the reverse rotation direction, even if a second control signal having a duty cycle range of 0% or 100% is received, the rotation direction and rotation speed of the motor 3 continue to correspond to the motor 3 not rotating or the motor 3 being driven in the reverse rotation direction.

[0024] This prevents the driver 2 from erroneously recognizing the first control signal as having received the second control signal to drive the motor 3 in the reverse direction, resulting in erroneous control. It is difficult to clearly identify the frequency of a pulse-width modulation (PWM) signal with a duty cycle range of 0% or 100%. Therefore, even if the driver 2 receives a second control signal with a duty cycle range of 0% and a pulse-width modulation (PWM) signal with a duty cycle range of 100% in the above-described state, preventing the driver 2 from erroneously recognizing the first control signal as having received the first control signal and driving the motor in the forward direction contributes to preventing erroneous operation. [Industrial Applicability]

[0025] The present invention can be used in, for example, motors and motor control. [Explanation of symbols]

[0026] 1. Control section 2 Drive unit 3 motors

Claims

1. A method for controlling a motor, comprising: driving the motor in a forward rotation direction at a rotation speed corresponding to a duty cycle range of a first control signal, the first control signal being a pulse width modulation (PWM) signal; a second control signal is received, the second control signal being a pulse width modulated (PWM) signal having a different frequency than the first control signal, the second control signal corresponding to the direction and speed of rotation of the motor being such that the motor is not rotating; A method of controlling a motor, wherein the motor is driven in a reverse rotational direction.

2. 2. A motor control method according to claim 1, comprising: When the motor is driven in the forward rotation direction and receives the second control signal, A method of controlling a motor, wherein the motor is driven in a reverse rotational direction.

3. 2. A motor control method according to claim 1, comprising: When the direction and speed of rotation of the motor correspond to the motor not rotating and the second control signal is received, The motor is driven in a reverse direction regardless of whether the duty cycle of the received second control signal is in the range of 0% to 100%.

4. 4. The motor control method according to claim 3, When the rotation direction and rotation speed of the motor correspond to the motor not rotating or when the motor is driven in a reverse rotation direction, A method of controlling a motor, wherein the duty cycle range of the received first control signal is greater than 0% and less than 100%.

5. 4. The motor control method according to claim 3, When the rotation direction and rotation speed of the motor correspond to the motor not rotating or when the motor is driven in a reverse rotation direction, Even if you receive a pulse width modulated (PWM) signal with a duty cycle range of 0% or 100%, Subsequently, the rotation direction and rotation speed of the motor correspond to the motor not rotating or the motor is driven in the reverse rotation direction.

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