JPH0632578B2 - Motor control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a motor control device that controls the drive of a rotating motor.

[Prior Art] Recently, as a motor control device, in order to accurately rotate a DC motor at a predetermined number of rotations, the oscillation output of a crystal oscillator and the rotation detection signal from the motor are matched in frequency and phase. Those using a phase locked loop (PLL) circuit for controlling have been developed and put into practical use.

However, in the above-mentioned device, it is impossible to prevent the abnormal rotation of the motor when some trouble occurs in the control system of the motor or when the rotation of the motor fails.

[Problems to be Solved by the Invention] As described above, the present invention has a drawback that abnormal rotation of a motor cannot be immediately stopped when some trouble occurs in the control system of the motor or a failure occurs in the rotation of the motor. It is an object of the present invention to provide a motor control device that can immediately stop abnormal rotation of a motor when some malfunction occurs in the control system of the motor or a failure occurs in the rotation of the motor.

[Means for Solving the Problems] A motor control device according to the present invention includes a rotating motor, a rotation pulse generating means for generating a rotation pulse having a frequency corresponding to the rotation speed of the motor, and a reference for generating a reference signal having a predetermined frequency. A signal generating means, a supplying means for supplying a motor-on signal, and a frequency and a phase of a rotation pulse generated by the rotation pulse generating means and a frequency of a reference signal from the reference signal generating means when the motor-on signal is supplied by the supplying means. And a phase are compared, two voltages corresponding to the comparison result are output, and when the comparison result is coincident, a comparison unit that outputs a lock signal and two voltages output from the comparison unit are added. , By applying electric power obtained by comparing and amplifying the added value with a predetermined value to the motor, the rotating means for rotating the motor, and the supplying means. When the lock-on signal from the comparing means is not supplied for a predetermined time while the motor-on signal is being supplied, it comprises a prohibiting means for prohibiting the supply of the motor-on signal from the supplying means to the comparing means. .

[Operation] According to the present invention, the frequency and phase of the rotation pulse obtained by the rotation pulse generation means and the reference signal generation according to the rotation of the motor when the motor-on signal is supplied by the supply means in the above-mentioned configuration. The frequency and the phase of the reference signal from the means are compared by the comparing means, and two voltages corresponding to the comparison result are output. When the comparison result is in agreement, a lock signal is output and the output 2 By adding two voltages and applying a power obtained by comparing and amplifying the added value to a predetermined value to the motor, the motor is rotated, and when the motor-on signal is supplied by the supply means, the lock from the comparison means is applied. The supply of the motor-on signal from the supply means to the comparison means is prohibited when the signal is not supplied for a predetermined time.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the motor 1 rotates the optical disk 23 in the optical disk device shown in FIG. The motor 1 is composed of a hall motor whose rotation speed is controlled by a power amplification section (rotation means) 22 described later. A rotation pulse generator (rotation pulse generation means) 2 is mechanically directly connected to the shaft of the motor 1, and the rotation pulse generator 2 is widely used as a sonomotor for generating a pulse having a frequency proportional to the rotation of the motor 1. It is a well-known one used. The rotation pulse output from the rotation pulse generator 2 is supplied to a rotation pulse input terminal EP of a PLL (Phase Locked Loop) circuit (comparing means) 3.

A motor-on signal (motor control signal) from a control circuit (not shown) is supplied to one input terminal of the AND circuit 4, and the other input terminal of the AND circuit 4 is supplied from the lock signal output terminal LOCK of the PLL circuit 3. Lock signal is supplied via the inverter circuit 5. AND circuit 4
Is supplied to the charging / discharging circuit 6. This charge / discharge circuit 6
Is composed of an integrating circuit composed of a resistor 7 and a capacitor 8, and a series circuit composed of a resistor 9 connected in parallel to the resistor 7 and a diode 10 having the polarity shown in the figure. The charge / discharge circuit 6 has a time constant τ when the AND circuit 4 is a logical "1" signal.
_The capacitor 8 is charged at ₁ and the charging voltage of the capacitor 8 is discharged by the diode 10 and the resistor 9 at the time constant τ ₂ when the AND circuit 4 is a logical "0" signal. Resistance 7 so that time constant τ ₁ >> τ ₂
And the constant of the capacitor 8 is determined.

The output of the charging / discharging circuit 6, that is, the signal from the connection point of the resistor 7 and the capacitor 8 is supplied to the reset input terminal of the flip-flop circuit (FF circuit) 11, and the FF circuit 1
The motor-on signal is supplied to the set input terminal 1 through the inverter circuit 12.

The set output of the FF circuit 11 is supplied to one input terminal of the AND circuit 13, and the motor-on signal is supplied to the other input terminal of the AND circuit 13. The output of the AND circuit 13 is supplied to the motor-on input terminal MON of the PLL circuit 3. The oscillation signal (reference clock) from the reference signal oscillator (reference signal generating means) 14 is supplied to the clock pulse input terminal CP of the PLL circuit 3.

The PLL circuit 3 operates when a motor-on signal is supplied to the motor-on input terminal MON, compares the reference clock from the reference signal oscillator 14 with the rotation pulse from the rotation pulse generator 2, and determines the difference in frequency. Output voltage from the auto frequency control output end AFC, and output a voltage according to the phase difference from the auto phase control output end APC. When the above comparison results are in agreement, the lock signal output end LOCK The lock signal is output.

The signal from the output terminal AFC and the signal from the output terminal APC of the PLL circuit 3 are supplied to the inverting input terminal of the differential amplifier 17 via the resistors 15 and 16, respectively, and to the non-inverting input terminal of the differential amplifier 17. Is supplied with a low voltage from a series circuit including resistors 18 and 19. Also,
Between the output terminal and the inverting input terminal of the differential amplifier 17,
A parallel circuit including a resistor 20 and a capacitor 21 is connected.

Here, the power amplification unit 22 includes the resistors 15, 16, 18, 19, 20, the differential amplifier 17, and the capacitor 21.
Is configured. The power amplification unit 22 adds outputs from the output end AFC and the output end APC of the PLL circuit 3,
Rotating electric power is applied to the motor 1 by comparing and amplifying it with a certain constant value.

Next, in such a configuration, the operation will be described with reference to the flowchart shown in FIG. For example, it is now assumed that the motor-on signal is supplied from a control circuit (not shown). At this time, the FF circuit 11 is set, and the gate of the AND circuit 13 is opened by this set output.
As a result, the motor-on signal is supplied to the input terminal MON of the PLL circuit 3 via the AND circuit 13. Then P
The LL circuit 3 starts operating, and the reference clock from the reference signal transmitter 14 and the rotation pulse from the rotation pulse generator 2 corresponding to the rotation of the motor 1 are compared to determine a voltage corresponding to the difference in frequency. , And a voltage corresponding to the phase difference are output from the output terminals AFC and APC to the power amplification unit 22, respectively.

As a result, the power amplification unit 22 adds the voltages from the output terminals AFC and APC, compares and amplifies the added value with a predetermined value,
This amplified output is supplied to the motor 1. As a result, the output from the power amplification unit 22 supplies a current to each coil in the motor 1 to control the rotation.

Further, the AND circuit 4 is established by the motor ON signal, the output of the AND circuit 4 becomes a logical "1" signal, and the capacitor 8 is charged with the time constant τ ₁ .

When the rotation pulse of the motor 1 and the frequency and phase of the reference clock match, the PLL circuit 3 outputs the output terminal LOC.
The lock signal is output from K.

Therefore, the rotation speed of the motor 1 reaches a predetermined rotation speed within a fixed time after the motor-on signal is output, and the lock signal is output from the PLL circuit 3. Then, AND circuit 4
Is not established, and the output of the AND circuit 4 becomes a logic "0" signal. As a result, the diode 10 and the resistor 9 are discharged with the time constant τ ₂ before the charging voltage of the capacitor 8 reaches the threshold level V _T.

By the way, when the rotation speed of the motor 1 does not reach the predetermined rotation speed even after a lapse of a certain time after the motor-on signal is output, when the charging voltage of the capacitor 8 reaches the threshold level V _T , the FF circuit 11 It is reset, the gate of the AND circuit 13 is closed by the reset output, and the motor-on signal from the control circuit (not shown) is PLL.
The supply to the circuit 3 is stopped, and the PLL circuit 3 stops the driving of the motor 1.

Further, even if the lock signal is output, when the motor control system has some trouble or the rotation of the motor fails, that is, when the motor 1 has an abnormality, the PLL circuit 3
Interrupts the lock signal.

As a result, the AND circuit 4 is established, the output of the AND circuit 4 becomes a logical "1" signal, and the capacitor 8 is charged with the time constant τ ₁ .

When the above abnormality continues for a predetermined time, the capacitor 8
When the charging voltage of F reaches the threshold level V _T , F
The F circuit 11 is reset, the AND circuit 13 is closed by the reset output, the motor-on signal from the control circuit (not shown) is cut off, and is not supplied to the PLL circuit 3. As a result, the voltage is not supplied from the PLL circuit 3 to the power amplification unit 22, and as a result, the motor 1 stops.

After that, when the lock signal is monitored by the control circuit (not shown), it is determined that the lock signal is not output, and the output of the motor-on signal is stopped.

This motor-on signal is no longer supplied to the AND circuit 4, and the output of the AND circuit 4 becomes a logical "0" signal. As a result, the charging voltage of the capacitor 8 is discharged with the time constant τ ₂ by the diode 10 and the resistor 9.

In this way, when abnormal rotation of the motor occurs, the rotation of the motor can be stopped surely and immediately, and the control circuit does not have to constantly monitor the motor, for example, every few seconds. Further, the charge / discharge circuit and the FF circuit may be realized by a monostable multivibrator.

[Effects of the Invention] As described in detail above, according to the present invention, a motor control device capable of immediately stopping the abnormal rotation of a motor when some malfunction occurs in the control system of the motor or a failure occurs in the rotation of the motor. Can be provided.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an electric circuit diagram schematically showing the overall configuration, FIG. 2 is a schematic configuration diagram of an optical disc device showing a relationship between a motor and an optical disc, and FIG. FIG. 4 is a timing chart for explaining the main part of the operation. 1 ... 2 ... Rotation pulse generator (rotation pulse generation means), 3 ... PLL circuit (comparison means), 4, 13 ... AND circuit, 6 ... Charge / discharge circuit, 8 ... Capacitor, 11
... FF circuit, 14 ... Reference signal oscillator (reference signal generating means), 17 ... Differential amplifier, 22 ... Power amplification section.

Claims (1)

[Claims] 1. A rotating motor, a rotation pulse generating means for generating a rotation pulse having a frequency corresponding to the rotation speed of the motor, a reference signal generating means for generating a reference signal of a predetermined frequency, and a motor-on signal. It operates by receiving the supply of a motor-on signal from the supply means, and compares the frequency and phase of the rotation pulse by the rotation pulse generation means with the frequency and phase of the reference signal from the reference signal generation means. A comparison unit that outputs a motor drive signal according to the comparison result and further outputs a lock signal when the comparison result is in agreement, and a motor at a rotation speed according to the motor drive signal output from the comparison unit. Even if a predetermined time has elapsed after the motor-on signal is supplied by the rotating means that rotates and the supply means, the comparison means locks it. Signal is not output, and when the lock signal is not output again by the comparison means even if a predetermined time has elapsed after the output of the lock signal by the comparison means was interrupted without continuing, the supply means described above is used. A motor control device comprising: a prohibition unit that prohibits supply of a motor-on signal to the comparison unit.