JPH0491686A - Motor controller - Google Patents

Abstract

PURPOSE:To control a shortest stop time excellently in response to the kind of load by measuring a time until the number of revolution of a motor reaches a specified value, controlling the quantity of braking and drive in response to a measuring time until a reverse rotation signal from a direction detecting section is emitted and stopping the motor. CONSTITUTION:A controller 14 measures a time until frequency from an FG1 reaches specified frequency, until a motor 2 reaches the fixed number of revolution, when a reverse rotation signal is input. When measurement is completed, pulse width corresponding to the measuring time is set, and the pulse width is output to a driver 10 or pulses are output to the driver 10 in proportional to the frequency of the FG1. A rotational direction detector 4 discriminates the direction of rotation by the phase difference of the FG1 and an FG2, a reverse rotation signal is input to a main controller 15 when the direction of rotation is reversed, the main controller 15 receives the reverse rotation signal and inputs a motor OFF signal to the driver 10, and the motor 2 is stopped instantaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a motor control device for stopping a rotating motor.

BACKGROUND OF THE INVENTION For example, a brushless motor is generally composed of a rotor made of permanent magnets and a stator having a plurality of windings. This brushless motor is driven by detecting the rotation angle of the rotor with respect to the stator, and based on this, each winding of the stator is sequentially driven in a predetermined direction. Such a motor is used, for example, as a spindle motor for an optical disk drive, and is required to stop for a short period of time. Conventionally, when braking a brushless motor, a constant voltage is applied in the opposite direction to each of the windings for a period of time in response to a reverse rotation command.

In this case, the voltage is applied until the motor decelerates to a predetermined rotation speed, and when the motor reaches the predetermined rotation speed, the reverse rotation command is canceled, that is, the voltage application is canceled, and the motor is allowed to stop naturally from the predetermined rotation speed. be done.

Another braking method is to apply a voltage according to a reverse rotation command until the rotation of the motor is reversed, and after the rotation is reversed, the voltage application is released and the motor is allowed to come to a natural stop from the reversed state.

In this case, the shortest stopping time is obtained by changing the braking force depending on the difference in motor load, for example, the weight of a glass disk and a plastic disk in an optical disk.

Problems to be Solved by the Invention However, if the motor loads are different, if the braking force is kept constant and the stopping time is set, even if it is possible to perform good stopping time control for one load, it may not be appropriate for the other load. There is a problem that it is impossible to perform proper control.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor control device that performs good control of the shortest stop time depending on the type of load driven by the motor.

Means for Solving the Problems FIG. 1 shows an explanatory diagram of the principle of the present invention for solving the above problems.

In FIG. 1, a motor control device 1 controls the rotation of a motor 2 having a stator (or rotor) consisting of a plurality of windings.
In response to the stop command, the winding is electrically braked and stopped.

In the figure, reference numeral 3 denotes a rotation speed detection section, which outputs a signal according to the rotation speed of the motor 2. 4 is a direction detection section, and motor 2
Detect the direction of rotation. Reference numeral 5 denotes a control unit, which brakes and drives the winding in response to the stop command, measures the time until the rotational speed of the motor reaches a predetermined value using the rotational speed detection unit, and measures the time until the rotational speed of the motor reaches a predetermined value using the rotational speed detection unit. When a reversal signal is issued, the motor is stopped by controlling the braking drive amount of the winding according to the measurement time.

As shown in Figure 1, after braking the motor 2 in the reverse rotation direction, the time required for the motor's rotation speed to drop to a predetermined value is measured, and the braking drive amount of the windings is determined according to the measured time. is under control. That is, if the time taken for the rotation speed to drop to the predetermined rotational speed is long, the braking drive of the winding is set to be increased, and if it is short, the braking drive of the winding is set to be decreased.

As a result, even if the load driven by the motor is different, braking drive can be performed in accordance with the load, and good control of the shortest stopping time can be achieved with a wide range of load types.

Example Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention. In the figure, the motor control device 1 includes a motor 21, a rotation speed detection section 3. It is composed of a direction detection section 4 and a control section 5.

The motor 2 is, for example, a brushless motor that includes a rotor (not shown) made of a permanent magnet and a stator made of windings 2a to 2c.

The rotation speed detection unit 3 has a frequency of FG (Frequency G
enerator) 1 and FG2, and motor 2
Detects both forward and reverse rotational frequencies.

The direction detection unit 4 is composed of, for example, a D-type flip-flop that detects the rotation direction based on the rotation frequency from the FGI and FC2.

The control unit 5 includes a driver 10. which brakes and drives the windings 2a to 2c of the motor 2. Comparator 11. Fixed frequency oscillator 12. Amplifier 13. It is composed of a controller 14.

Comparator If is the rotation speed of FGI and fixed frequency oscillator 12.
The frequencies of the two are compared, and the output thereof is input to the driver IO via the amplifier 13 and the switch S1.

The controller 14 measures the time until the rotational speed of the motor 2 or FGI reaches a predetermined value based on the stop (reverse rotation) command of the forward/reverse rotation signal, and adjusts the winding 2a according to the measured time.
The braking drive amount of ~2c is transmitted to driver 1 via switch S1.
0 (details will be described later). Here, the term "until the rotational speed of the motor 2 reaches a predetermined value" includes both cases where the rotational speed of the motor 2 decreases to the predetermined rotational speed due to braking and cases where the rotational speed of the motor 2 increases from a stopped state to a predetermined rotational speed. .

The driver IO receives normal rotation from the main controller 15.
Based on the reverse rotation signal and the motor 0N10FF signal, the windings 2a to 2C are brake-driven with the drive amount input from the switch S1. Here, the main controller 15 inputs a direction signal from the rotation direction detection section 4.

Here, the operation of the motor control device I will be explained.

First, when the motor 2 is in normal rotation, the switch S of the control section 5 is connected to the amplifier 13 side in response to a normal rotation/reverse rotation signal. Therefore, the comparator 11 compares the phases of the pulses from the FGI and the pulses from the fixed frequency oscillator 12, and if there is a phase difference, the driver IO performs feedback rotation control of the windings 2a to 2C in a direction to eliminate the phase difference. conduct.

When a reverse rotation signal, which is a stop command, is input to the driver IO and the controller 14, the switch S1 is connected to the controller 14 side. When the controller 14 receives a reverse rotation signal, it changes the frequency from the FGI or a predetermined period.
That is, the time required for the motor 2 to reach a predetermined rotational speed is measured. In this case, during the measurement, a signal with a constant voltage value (constant pulse width) for braking is output to the driver 10. When the measurement is completed, a pulse width corresponding to the measurement time is set and outputted to the driver 10, or the pulse is made proportional to the frequency of the FGI and outputted to the driver IO. That is, when the load on the motor 2 is heavy and the measurement time is long, the controller 14 sets the pulse width to be wide, and conversely, when the load is light and the measurement time is short, the controller 14 sets the pulse width to be narrow.

Then, the rotation direction detector 4 detects the rotation direction by FGI and FG.
2, and when the rotation direction is reversed, a reversal signal is input to the main controller 15, and in response to this, the main controller 15 instructs the driver lO to turn the motor off.
When the F signal is input, the motor 2 immediately stops.

In this way, optimal braking and driving can be performed depending on the type of load on the motor 2, and control can be achieved over a wide range with the shortest stopping time.

Here, FIG. 3 shows a block diagram of the controller 14. In FIG. 3, the controller I4 includes period detection means 20. Time measuring means 21, pulse width setting means 2
2. Pulse output generation means 23 and continuous output generation means 24
Consisted of.

The period detection means 20 inputs the frequency pulse from the FGI and switches the switch S2. The switch S2 switches between the continuous output generating means 24 and the pulse output generating means 23, and sends these outputs to the switch S1.

The time measuring means 21 measures the time from the reverse rotation command to the output of the period detecting means 20, and outputs the measured value to the pulse width setting means 22 after the measurement.

The pulse output generating means 23 outputs a signal having the pulse width set by the pulse width setting means 22 in proportion to the frequency of the FG 10.

Further, FIG. 4 shows a block circuit diagram of an application example of the period detecting means 202, the time measuring means 21, and the pulse width setting means 22. In FIG. 4, the period detection means 20 is composed of, for example, a comparator 30, which compares the frequency of FGI and the period of the clock, and outputs the signal when the frequency of FG1 reaches a set period (see FIG. ■Reference). The time measuring means 21 includes a counter 40 that measures time based on a clock in response to a reverse rotation command, and a latch 41 that temporarily holds the output of the counter 40. Further, the pulse width setting means 22
Comparators 501 to 50 are connected in parallel according to the type of pulse width to be set.

Therefore, FIG. 5 shows a time chart of the operation of the time measuring means 21 and will be explained. First, reverse command (Fig. 5 ■)
When is input to the counter 40 of the time measuring means 21, the counter 40 counts the clock (■ in FIG. 5) from that point onwards. This count value is input to the latch 4I, and the count value from the latch 41 or the counter 40 is latched by the output from the comparator 30 of the period detecting means 30 ((■) in FIG. 5). In other words, the latch 41 keeps the count value "0" until there is an output from the comparator 30, as shown in FIG.
After latching, the count value "10" shown in FIG. 5 is output. Note that during the counting period until the comparator 30 outputs the output to the latch 41, the continuous output generating means (Fig.
4), the signal is output to the driver 10 via the switches S1 and S2 with a predetermined pulse width.

The output of the latch 41 is input to the pulse width setting means 22, and the output of the latch 41 is input to the respective comparators 50. -50e, a comparator that matches the count value sets a pulse width, and outputs it to the pulse generating means 23. The pulse output generating means 23 sends a control signal to the switch S2 with the pulse width set by the pulse width setting means 22. At this time, the switch S2 is connected to the pulse output generating means 23 side by the output of the comparator 30 of the period detecting means 20 (see FIG. 3). Therefore, the output from the pulse output generating means 24 is input to the driver IO via the switches S1 and S2 to brake and drive the windings 2a to 2c of the motor 2, thereby bringing the motor 2 to a stopped state in a short time. .

Next, FIG. 6 shows a block diagram showing another application example of FIG. 3. That is, the continuous generation means 24 and the pulse output generation means 23 in the controller 14 of FIG. 3 are replaced with a mono-multivibrator 25. In this case, the pulse width setting means 22 is constituted by, for example, a D/A converter. That is, the output sent to the switch S1 during time measurement is continuously outputted by the mono multivibrator 25 at the frequency of FGI, and after the time measurement, the voltage value of the time count value converted by the pulse width setting means 22 is D/A converted. The pulse width of the FGI is set and output to the driver 10 via the switch S1.

Note that the time measuring means 21 is used to measure the time required for the rotation speed to decrease from a constant rotation state to a predetermined rotation speed by a reverse rotation command, or as described above, the time measurement means 21 measures the time required for the rotation speed to decrease from a constant rotation state to a predetermined rotation speed. It is also possible to measure the time it takes for the rotation speed to rise to a predetermined number, and set the pulse width based on the measured time when a reverse rotation command is issued.

Furthermore, although the above embodiments have been described in the case of a motor or a brushless motor, the present invention is not limited thereto, and can be applied to a motor that can be reversed in the field direction of a plurality of windings.

Effects of the Invention As described above, according to the present invention, the time required for the rotational speed of the motor to reach a predetermined rotational speed is measured, and the windings are braked and driven according to this measured time. By performing braking and driving according to the load being applied, it is possible to perform good control of the shortest stop time under a wide range of load types.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is a block diagram of the controller in FIG. 2, and FIG. 4 is a period detection means in FIG. 3. , a block circuit diagram of one application example of the time measurement means and pulse width setting means, FIG. 5 is a time chart of the operation of the time measurement means in FIG. 4, and FIG. 6 is a block configuration of another application example of FIG. 3. It is a diagram. l...Motor control device, 2...Motor, 3...Rotation speed detection unit, 4...Direction detection unit, 5...Control unit, l
O...driver, 14...controller, 20...
- Period detection means, 21... Time measurement means, 22...
Pulse width setting means, 23...Pulse output generation means, 2
4...Continuous output generation means.

Claims (1)

[Scope of Claims] A motor control device that stops the rotation of a motor having a stator or rotor consisting of a plurality of windings by electrically braking the windings in response to a stop command, comprising: a rotational speed detection section that outputs a signal according to the rotational speed detection section; a direction detection section that detects the rotational direction of the motor; Measure the time it takes to reach a predetermined value, and until the direction detection section issues a reversal signal,
A motor control device comprising: a control section that controls a braking drive amount of the winding to stop the motor according to the measurement time.