JP2012070489A - Drive control device and drive control method for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control device and a drive control method for a motor, capable of achieving simple setting of a plurality of control items.SOLUTION: A drive control device 2 for a motor includes a pulse information detection circuit 5, a pulse information conversion circuit 6, a control execution processing circuit 7 and an inverter circuit 4. A PWM control signal of one system is input into the drive control device 2, a control item is selected according to a frequency thereof, and the control item selected according to a duty ratio is controlled. Thus, the drive control device 2 for a motor can set a plurality of control items even in a simple circuit configuration.

Description

  The present invention relates to a motor drive control device and a motor drive control method for controlling drive of a motor.

  Various methods for giving a control command to a motor driver have been proposed.

  For example, Patent Document 1 discloses a method of selecting a communication method and setting a command content in a motor driver by data communication. The motor drive control device includes communication means for adding the type information of the motor control method to the result calculated by the numerical value calculation means and transferring the result to a plurality of motor drivers.

  Patent Document 2 discloses a method in which a PWM (Pulse Width Modulation) control signal is input to a motor driver that does not have communication means, and the speed is set with the duty ratio. This drive control device includes an ASIC (Application Specified Integrated Circuit) that generates a PWM control signal and a motor driver that drives a motor based on the PWM control signal.

  In addition, there is known a method of giving a control command by setting an input terminal of a motor driver to high or low.

Japanese Patent Laid-Open No. 11-149308 JP 2006-42525 A

  In order to issue a control command by the method of Patent Document 1, there is a problem that the command transmission side and the motor driver side must have the same communication function.

  Further, when a control command is issued by the method of Patent Document 2, there is a problem that only one control item can be set by one system of PWM control signals.

  Also, when setting the input terminal of the motor driver to high or low, in order to set multiple control items, it is necessary to provide multiple input terminals according to the number of control items, and the configuration of the motor driver is complicated There is a problem of becoming.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor drive control device and a motor drive control method capable of easily setting a plurality of control items.

  According to one aspect of the present invention, a motor drive control device includes a pulse information detection circuit, a pulse information conversion circuit, a control execution processing circuit, and a drive circuit. The pulse information detection circuit detects the frequency and duty ratio of a pulse width modulated control signal for controlling one of the plurality of control items. The pulse information conversion circuit selects one of the plurality of control items according to the frequency of the control signal. The control execution processing circuit controls the selected control item according to the duty ratio of the control signal. The drive circuit supplies electric power to the motor according to the control content of the control item to drive the motor.

  According to the present invention, in order to select a control item according to the frequency of the PWM control signal and to control the control item selected according to the duty ratio, a plurality of components with a simple configuration of inputting one system of the PWM control signal are provided. Control items can be set.

1 is a schematic block diagram of a motor drive control system according to a first embodiment of the present invention. The figure which shows an example of the relationship with the setting value of the frequency of the PWM control signal with respect to each channel, a control item, and a duty ratio. FIG. 2 is a more specific schematic block diagram of a motor drive control system. The schematic block diagram of the drive control system of the motor which concerns on the 2nd Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a motor drive control device and a motor drive control method according to the present invention will be specifically described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic block diagram of a motor drive control system according to a first embodiment of the present invention. The motor drive control system includes a PWM signal generation circuit 1, a motor drive control device (hereinafter, drive control device) 2, and a motor 30. The PWM signal generation circuit 1 may be prepared by a user, and the drive control device 2 may be designed in accordance with this, or may be built in the drive control device 2.

  The PWM signal generation circuit 1 is configured by, for example, a microcomputer or a function generator. The PWM signal generation circuit 1 supplies one system of PWM control signals to the drive control device 2. In accordance with the PWM control signal, one of a plurality of control items of the motor 30 such as a rotation speed and a rotation direction of the motor 30 is controlled. The PWM control signal can be variably controlled in frequency and duty ratio. The duty ratio is, for example, a ratio of a period that is high in one cycle.

  The drive control device 2 includes a control circuit unit 3 and an inverter circuit (drive circuit) 4.

  The control circuit unit 3 receives the PWM control signal from the PWM signal generation circuit 1. Then, the control circuit unit 3 selects one of the control items according to the frequency of the PWM control signal, and controls the selected control item according to the duty ratio. Further, the control circuit unit 3 supplies a drive signal corresponding to the control content to the inverter circuit 4. The inverter circuit 4 drives the motor 30 by supplying power to the motor 30 according to the drive signal.

  As described above, the present embodiment is characterized in that a plurality of control items can be controlled by one system of PWM control signals by using not only the duty ratio of the PWM control signal but also the frequency.

  The internal configuration of the control circuit unit 3 will be described more specifically. The control circuit unit 3 includes a pulse information detection circuit 5, a pulse information conversion circuit 6, and a control execution processing circuit 7. The pulse information conversion circuit 6 includes a control item determination circuit 8 and a control execution destination distribution circuit 9.

  The pulse information detection circuit 5 receives the PWM control signal supplied from the PWM signal generation circuit 1 and detects the pulse information, that is, the frequency and the duty ratio. For example, the pulse information detection circuit 5 can detect the frequency of the PWM control signal by measuring the time from a certain rising edge of the PWM control signal to the next rising edge. The pulse information detection circuit 5 can detect the duty ratio by measuring the time from one rising edge of the PWM control signal to the next falling edge and dividing the measurement time by the reciprocal of the frequency.

  The control item determination circuit 8 in the pulse information conversion circuit 6 selects one of the control items according to the duty ratio of the PWM control signal. The control execution destination distribution circuit 9 distributes the output destination of the duty ratio of the PWM control signal according to the selected control item. The control execution processing circuit 7 controls the selected control item according to the duty ratio of the input PWM control signal.

  FIG. 2 is a diagram illustrating an example of the relationship between the frequency of the PWM control signal for each channel, the control item, and the set value of the duty ratio.

  If the frequency of the PWM control signal is 12 kHz to 18 kHz (channel 1), the rotation speed is selected as a control item. The target rotation speed is set in proportion to the duty ratio, for example. If the frequency of the PWM control signal is 22 kHz to 28 kHz (channel 2), the rotation direction is selected as a control item. The rotation speed is set clockwise (CW) when the duty ratio is 1 to 50% and counterclockwise (CCW) when the duty ratio is 51 to 99%.

  If the frequency of the PWM control signal is 32 kHz to 38 kHz (channel 3), the PID control parameter is selected as a control item. For example, when the duty ratio is 1 to 30%, the P coefficient is set based on a table representing the relationship between a predetermined duty ratio and the P coefficient. Hereinafter, various control items are selected according to the frequency, and the control items are controlled according to the duty ratio. If the frequency of the PWM control signal is 92 kHz to 98 kHz (channel 9), the lock protection time is selected as a control item. The lock protection time is set in proportion to the duty ratio, for example.

  As shown in the figure, it is desirable to provide a blank frequency band (for example, 18 kHz to 22 kHz, 28 kHz to 32 kHz, etc.) to which no channel is assigned between frequencies to which channels are assigned. The reason is that even when an error is included in the frequency of the PWM control signal, a malfunction in response to the command is prevented and the operation is performed reliably.

  Thereby, for example, when a PWM control signal of 18 kHz should be generated to control the rotation speed, but when an error occurs and becomes 18.5 kHz, no control item is set and other control items are set. Can be prevented from being erroneously controlled. Further, by using a blank frequency band, the upper limit of channel 1 may be set to 18 kHz and the actual operation guarantee upper limit may be set to 19 kHz in terms of specifications. As a result, not only malfunction can be prevented, but also the rotational speed can be controlled even when some errors occur as described above.

  Although the figure shows an example in which nine control items are controlled using a frequency of 12 to 98 kHz, these may be changed as appropriate. For example, a higher frequency or lower frequency PWM control signal may be used. Further, other control items that can be set by software may be added, or some control items may be omitted.

  FIG. 3 is a more specific schematic block diagram of the motor drive control system. The control execution processing circuit 7 in the figure mainly shows a processing circuit for controlling the rotation speed corresponding to the channel 1 in FIG. 2, and other control items are omitted. Hereinafter, a case where a PWM control signal having a frequency of 15 kHz is input to the control circuit unit 3 and the rotation speed of the channel 1 is selected as a control item will be described as an example.

  The motor 30 is a three-phase brushless motor 30 that does not have a position detection sensor. Motor 30 has a U-phase armature coil, a V-phase armature coil, and a W-phase armature coil (not shown) connected to three terminals U, V, and W, respectively.

  The inverter circuit 4 includes a PMOSFET (Field Effect Transistor) Q1 and an NMOSFET Q2, a PMOSFET Q3 and an NMOSFET Q4, and a PMOSFET Q5 and an NMOSFET Q6 that are connected in cascade. A power supply voltage Vcc is applied between the source of the PMOSFET and the source of the NMOSFET, and these drains are connected to the U terminal of the motor 30. The same applies to other FETs.

  The inverter circuit 4 is supplied with a pulse width modulated drive signal (hereinafter referred to as PWM drive signal) from the control circuit unit 3, and turns on one of the PMOSFETs and one of the NMOSFETs. For example, when PMOSFET Q1 and NMOSFET Q4 are turned on, a drive current flows through the U-phase armature coil and the V-phase armature coil in motor 30. A rotor (not shown) in the motor 30 is rotated by switching the armature coil through which the drive current flows in order. The rotational speed increases as the duty ratio of the PWM drive signal increases.

  The control item discriminating circuit 8 discriminates one of the plurality of control items determined in advance according to FIG. 2 according to the frequency of the PWM control signal detected by the pulse information detection circuit 5. The control execution destination allocation circuit 9 includes switches SW1 to SW9 corresponding to the respective channels in FIG. Among the switches SW1 to SW9, the switch corresponding to the control item determined by the control item determination circuit 8 is turned on.

  If the frequency of the PWM control signal is 15 kHz, this frequency corresponds to channel 1, and therefore the control item determination circuit 8 turns on the switch SW1 in the control execution destination distribution circuit 9. Then, the duty ratio of the PWM control signal detected by the pulse information detection circuit 5 is supplied to the control execution processing circuit 7 which is a processing circuit for controlling the rotation speed via the switch SW1.

  The control execution processing circuit 7 includes an induced voltage detection unit 10, a rotor position calculation unit 11, a speed control circuit 12, a duty control unit 13, and a commutation control circuit 14.

  The induced voltage detection unit 10 is connected to the terminals U, V, and W of the motor 30 and detects the zero cross point of the induced voltage generated at each terminal by the rotational drive of the motor 30. The rotor position calculation unit 11 calculates the position of the rotor based on the induced voltage at each terminal detected by the induced voltage detection unit 10. The position of the rotor can be calculated by detecting the point where the induced voltage becomes 0V.

  The speed control circuit 12 calculates the rotational speed of the rotor based on the zero cross point of the induced voltage of each terminal output from the induced voltage detection unit 10, and the rotational speed of the rotor is set by the duty ratio of the PWM control signal. The duty control unit 13 is controlled to be equal to the target rotational speed. More specifically, when the rotational speed of the rotor is larger (smaller) than the target rotational speed set by the duty ratio of the PWM control signal, the duty control unit 13 is set so that the duty ratio of the PWM drive signal becomes smaller (larger). Control.

  The duty control unit 13 sets the duty ratio of the PWM drive signal supplied to the inverter circuit 4 based on the control of the speed control circuit 12. The commutation control circuit 14 generates a PWM drive signal at a duty ratio determined by the duty control unit 13 in synchronization with the rotor position output from the rotor position calculation unit 11 and supplies the PWM drive signal to the inverter circuit 4. By this PWM drive signal, the FET in the inverter circuit 4 is on / off controlled, current flows through the armature coil in the motor 30, and the rotor rotates. As the duty ratio of the PWM drive signal is larger (smaller), the period during which each FET in the inverter circuit 4 is on becomes longer (shorter), so that the rotational speed of the rotor becomes faster (slower).

  By such feedback control, the rotation speed of the motor 30 approaches the target rotation speed set by the duty ratio of the PWM control signal.

  As described above, when the rotation speed (channel 1) is selected by the frequency of the PWM control signal, the duty ratio of the PWM control signal is supplied to the speed control circuit 12 which is a part of the processing circuit for controlling the rotation speed. . On the other hand, for example, when the rotation direction (channel 2) is selected by the frequency of the PWM control signal, the duty ratio of the PWM control signal is supplied to a processing circuit (not shown) for rotation direction control. The commutation control circuit 14 supplies the inverter circuit 4 with a PWM drive signal corresponding to the output of the processing circuit for controlling the rotation direction. Thereby, the motor 30 rotates in the rotation direction set by the duty ratio of the PWM control signal.

  For other control items, the motor is controlled by supplying the duty ratio of the PWM control signal to the processing circuit corresponding to the control item.

  As described above, in the first embodiment, the PWM control signal of one system is input to the drive control device 2, the control item is selected according to the frequency, and the selected control item is controlled according to the duty ratio. . Therefore, the motor drive control device 2 according to the present embodiment can set a plurality of control items while having a simple circuit configuration.

(Second Embodiment)
In the second embodiment described below, a trigger signal is supplied from the PWM signal generation circuit 1a to the control circuit unit 3 in addition to the PWM control signal.

  FIG. 4 is a schematic block diagram of a motor drive control system according to the second embodiment of the present invention. In FIG. 4, the same reference numerals are given to the components common to those in FIG. 3, and the differences will be mainly described below.

  The PWM signal generation circuit 1a of FIG. 4 supplies a trigger signal to the pulse information detection circuit 5a in the control circuit unit 3a. The trigger signal indicates the start timing of capturing the pulse information of the PWM control signal. When detecting the trigger signal, the pulse information detection circuit 5a detects the pulse information of the PWM control signal. Then, after a predetermined time has elapsed from the detection of the trigger signal, the pulse information detection circuit 5a finishes the capture. Thereby, it is possible to prevent the pulse information from being constantly taken into the pulse information conversion circuit 6 if the PWM control signal is continuously input from the PWM signal generation circuit 1a.

  As a modification, the trigger signal may indicate the end timing of capturing the pulse information of the PWM control signal. In this case, when a PWM control signal is input, the pulse information detection circuit 5a automatically starts to acquire pulse information, and ends the acquisition in synchronization with the trigger signal, whereby the pulse information conversion circuit 6 is constantly pulsed. Information can be prevented from being captured. The trigger signal may indicate both the capture start timing and capture end timing of the pulse information of the PWM control signal.

  Thus, in the second embodiment, the trigger signal is supplied from the PWM signal generation circuit 1a together with the PWM control signal to the pulse information detection circuit 5a. Therefore, the pulse information detection circuit 5a can determine the timing for taking in the pulse information of the PWM control signal, and can prevent the pulse information from being constantly taken into the pulse information conversion circuit 6. As a result, the motor 30 can be driven and controlled more stably.

  In each embodiment mentioned above, although the example which is a 3 phase brushless motor which does not have a sensor for position detection as motor 30 was shown, the kind of motor is not specifically limited, and the present invention is a hall element, for example. The present invention can be applied to a motor having a drive control device such as a motor having a position detection sensor such as a DC motor, an AC motor, and a servo motor.

  Based on the above description, those skilled in the art may be able to conceive additional effects and various modifications of the present invention, but the aspects of the present invention are not limited to the individual embodiments described above. Absent. Various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1, 1a PWM signal generation circuit 2, 2a Motor drive control device 3, 3a Control circuit part 4 Inverter circuit 5, 5a Pulse information detection circuit 6 Pulse information conversion circuit 7 Control execution processing circuit 8 Control item discrimination circuit 9 Control execution destination Distribution circuit 30 Motor

Claims (6)

A pulse information detection circuit for detecting a frequency and a duty ratio of a pulse width modulated control signal for controlling one of a plurality of control items;
A pulse information conversion circuit that selects one of the plurality of control items according to the frequency of the control signal;
A control execution processing circuit for controlling the selected control item according to the duty ratio of the control signal;
And a drive circuit that drives the motor by supplying electric power to the motor in accordance with the control content of the control item. The pulse information conversion circuit includes:
A control item determination circuit that determines one of the plurality of control items according to the frequency of the control signal;
The control execution destination distribution circuit which distributes the output destination of the duty ratio of the control signal detected by the pulse information detection circuit according to the determined control item. The motor drive control apparatus described.   3. The motor drive control device according to claim 1, wherein the control items include at least one of a rotation speed of the motor, a rotation direction of the motor, PID control, and a lock protection time.   The pulse information detection circuit receives a trigger signal indicating at least one of an acquisition start timing and an acquisition end timing of the control signal, and detects a frequency and a duty ratio of the control signal at a timing based on the trigger signal The motor drive control apparatus according to any one of claims 1 to 3.   Between the frequency band corresponding to one of the plurality of control items and the frequency band corresponding to the other one of the plurality of control items, a frequency that does not correspond to any control item The motor drive control device according to any one of claims 1 to 4, wherein a belt is provided. Detecting the frequency and duty ratio of a pulse width modulated control signal for controlling one of a plurality of control items;
Selecting one of the plurality of control items according to the frequency of the control signal;
Controlling a selected control item according to a duty ratio of the control signal;
A step of supplying power to the motor according to the control content of the control item to drive the motor.

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