JPH0522479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor drive control device, and more particularly to one in which the phase shift of a detection signal from a phase angle sensor can be electrically adjusted in order to optimize the phase angle of a drive signal.

FIG. 1 shows the basic configuration of a drive control device for a polyphase motor used in video tape recorders, turntables, etc. A phase angle sensor 4 composed of a Hall element etc. is installed on this motor 2,
The phase angle sensor 4 generates a phase angle signal by cutting the magnetic flux of the magnetic pole ring 6 that rotates in response to the motor 2. This phase angle signal is given as a control input to the drive control section 8, and the drive control section 8 forms a drive signal having a predetermined phase shift based on this rotation angle signal, and each drive signal is transmitted to each drive coil 2A,
2B and 2C are given separately. That is, the magnetic pole ring 6 is interlocked with the rotating part of the motor 2, and is formed by the drive control part 8 based on the phase angle signal obtained by the phase angle sensor 4 in response to the rotation of the magnetic pole ring 6. The drive signals are used to sequentially drive the drive coils 2A to 2B. FIG. 2 shows the positional relationship between these drive coils 2A and 2B and the phase angle sensor 4.

In such rotation control of the motor 2, it is necessary to perform phase matching between the phase angle sensor 4 and each of the drive coils 2A to 2C in order to increase the drive efficiency of the motor 2. Conventionally, this phase matching is A method of mechanically adjusting these mounting positions has been adopted. Such a mechanical adjustment method becomes more difficult as the number of poles increases, and the adjustment error increases. That is, if the phase alignment is insufficient, the motor 2
The drive efficiency of the motor will decrease, and even rotational ripples and whirring noises will occur due to drive unevenness, leading to a decline in performance. This inconvenience arises because the phase angle sensor 4 is composed of a photocoupler or the like, and the magnetic pole ring 6
The same problem occurs even if the plate is converted to a slit plate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor drive control device that can electrically adjust the error in the mounting position of a phase angle sensor with respect to a drive coil.

That is, in the motor drive control device of the present invention, as illustrated in FIG. 3, a phase angle sensor 4 installed on the motor 2 converts a phase angle detection signal generated in accordance with the rotation of the motor into a pulse. The sawtooth wave voltage obtained from the pulse converting means (waveform shaping circuit 10) that generates the sawtooth wave voltage and the first sawtooth wave generating circuit 16 that generates the sawtooth wave voltage in synchronization with the pulses generated by the pulse converting means. A first sample-and-hold circuit 18 is installed to hold the voltage in synchronization with the pulse, and the voltage held by the first sample-and-hold circuit is level-converted via level conversion means (voltage dividing circuit 20). Voltage comparison means (comparator 24) is installed to compare the holding voltage which has been extracted and level-converted with the sawtooth wave voltage of the first sawtooth voltage generation circuit, and tracking which generates pulses through this voltage comparison means. The sawtooth wave voltage obtained from the circuit 12 and a second sawtooth wave generation circuit 36 that generates a sawtooth wave voltage in synchronization with the pulse obtained from the tracking circuit is held in synchronization with the pulse. A second sample and hold circuit 38 is installed, and a voltage divider circuit 40 is installed that divides the held voltage held by the second sample and hold circuit at a constant ratio, and the voltage obtained through this voltage divider and the sawtooth a drive angle signal generation circuit 26 that generates a plurality of drive angle control signals having a specific phase by combining waveform voltages, and drive coils 2A, 2B of the motor.
A drive current corresponding to the holding voltage of the second sample hold circuit installed every 2 C is individually passed through the drive coil, and the drive angle control signal generated by the drive angle signal generation circuit is used to control the drive angle. The present invention is characterized in that it includes a drive circuit 54 that selectively switches the drive current for each drive coil.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIG. 3 shows an embodiment of the invention. In the figure, drive coil 2 of motor 2
A phase angle sensor 4 is provided for A, 2B, and 2C, and this phase angle sensor 4 is composed of a Hall element, a photocoupler, a frequency generator, and the like. The phase angle signal of the motor 2 detected by the phase angle sensor 4 is input to a waveform shaping circuit 10 and converted into a pulse waveform. This waveform shaping circuit 10 is composed of a program counter and the like, and converts the pulse into a pulse having the period of the phase angle signal, and inputs the pulse into the tracking circuit 12.

The tracking circuit 12 is installed to electrically adjust the phase error of the phase angle signal based on the installation position of the phase angle sensor 4 in response to the rotational speed of the motor 2. This tracking circuit 12 includes a frequency-voltage conversion circuit 14 that converts the frequency of a phase angle signal or a signal based on this phase angle signal into a voltage.
The frequency-voltage conversion circuit 14 is comprised of a first sawtooth wave generation circuit 16 and a first sample-and-hold circuit 18. That is, the output pulse of the waveform shaping circuit 10 is given to the sawtooth wave generation circuit 16 as a trigger signal, and is also inputted to the sample hold circuit 18 as a sample signal, and the sawtooth wave generation circuit 16 adjusts the frequency of the output pulse. The sample and hold circuit 18 samples and holds the peak value of this sawtooth wave, and generates a holding output. A voltage dividing circuit 20 as a level conversion means for adjusting the phase angle is installed between the output terminal of the sample hold circuit 18 and the sawtooth wave generation point level terminal of the sawtooth wave generation circuit 16. In the case of the embodiment, this voltage dividing circuit 20 is composed of a variable resistor 22. A comparator 24 is installed which generates a phase angle signal shifted by a set phase from the phase angle signal using the divided voltage output generated at the variable terminal of the variable resistor 22. That is, a phase setting voltage is applied to the inverting terminal (-) of the comparator 24, and a sawtooth wave is applied to its non-inverting terminal (+), and the operation of the comparator 24 is inverted by comparing both inputs. The phase-adjusted phase angle signal thus formed is provided to a drive angle signal generation circuit 26.

The drive angle signal generation circuit 26 is composed of a frequency-voltage conversion circuit 28, a phase shift circuit 30, and a logic circuit 32 for forming a drive angle signal. In this embodiment, the frequency-voltage conversion circuit 28 is a speed signal formation circuit. This speed signal output is output via an amplifier 34. That is, like the tracking circuit 12, the frequency-voltage conversion circuit 28 is composed of a second sawtooth wave generation circuit 36 and a second sample-hold circuit 38, and the phase-adjusted phase angle signal is used as a trigger signal and a sample signal. It consists of The phase shift circuit 30 includes a voltage divider circuit 40 that divides the output of the sample and hold circuit 38 based on the generation point level of the sawtooth wave of the sawtooth wave generation circuit 36 in order to form a phase shift of a predetermined angle. Voltage divider circuit 4
The voltage comparison circuit 42 individually compares each output of 0 with a sawtooth wave. In this example
In order to form a phase shift of 120°, the voltage divider circuit 40 is composed of a series circuit of resistors 44, 46 and 48 having the same resistance value, and the voltage comparator circuit 42 is composed of a series circuit of resistors 44, 48 having the same resistance value.
The phase setting voltage V ₁ formed at the connection points of 6 and 48,
It consists of comparators 50 and 52 to which V ₂ and a sawtooth wave are given as comparison inputs. The phase shift signal formed by each comparator 50, 52 is applied to a logic circuit 32 which forms a drive angle signal, and the drive angle signal is formed by combining the phase shift signals.

The drive angle signal generated by the drive angle signal generation circuit 26 is transmitted to the drive current switching circuit 54 of the drive circuit 54.
A, 54B, 54C are input at every predetermined phase shift, and each drive current switching circuit 54A, 54B, 5
A speed signal is applied to 4C from the amplifier 34. That is, the drive current switching circuits 54A, 54
In B and 54C, a drive current is generated based on the speed signal, and the flow time of this drive current is controlled by the drive angle signal. The drive currents obtained by the drive current switching circuits 54A, 54B, and 54C are applied to the drive coils 2A, 2B, and 2C for each set phase shift.

The operation of this drive control device will be explained with reference to the operation waveforms shown in FIGS. 4 and 5. In FIG. 4, A shows the waveform of the phase angle signal generated by the phase angle sensor 4 composed of a frequency generator, and B shows the pulse waveform obtained by converting this phase angle signal by the waveform shaping circuit 10. There is. That is, the period of the pulse shown in B corresponds to the period of the phase angle signal. C indicates a sawtooth wave generated by the sawtooth wave generation circuit 16 in response to this pulse input, and the peak value of each sawtooth wave corresponds to the period. In this sawtooth waveform, V _L1 is the reference level at the generation point of each sawtooth wave, Vph ₁
is the output of the sample and hold circuit 18, that is, the frequency -
The voltage conversion voltage, Vd, is the variable resistor 2 of the voltage divider circuit 20.
The phase setting voltage formed by the two variable terminals is shown. In this case, the phase setting voltage Vd is set according to the peak value of each sawtooth wave, that is, its value changes in proportion to the peak value. In other words, the phase setting voltage Vd determined by the position of the variable terminal of the variable resistor 22 changes in response to the frequency (period) of the phase angle signal, and this change occurs appropriately in accordance with the frequency fluctuation of the phase angle signal. It functions to correct phase errors. D shows the output pulse of the comparator 24 based on the comparison of the sawtooth wave and the phase setting voltage, the leading edge of which moves by the setting phase, the period of which corresponds to the period of the phase angle signal. E indicates a sawtooth wave generated by the sawtooth wave generation circuit 36 based on this pulse. That is, this sawtooth wave has a generation point shifted by the set phase θd while maintaining the period of the sawtooth wave shown in C. The reason why this phase shift differs depending on the peak value of each sawtooth wave is that
This is because the phase transition corresponds to the frequency of the original sawtooth wave, and as a result, the phase can be corrected in response to frequency fluctuations.

In FIG. 5, E' is the same waveform as shown in FIG. 4E. In this waveform, V _L2 is a sawtooth wave generation point reference level, Vph ₂ is the output of the sample and hold circuit 38, and V ₁ and V ₂ are phase distribution voltages formed at the voltage dividing point of the voltage dividing circuit 40. In this embodiment, the phase distribution is 120°. F, G are the outputs H, I, J generated by the comparators 50, 52 by comparing each phase distribution voltage and the sawtooth wave, and the outputs F,
A drive angle signal generated by the logic circuit 32 in combination with G is shown. This drive angle signal is transmitted to drive current switching circuits 54A, 54B, 5 of the drive circuit 54 for each phase.
4C switching control input, and the drive current conduction time based on the frequency-voltage conversion output given by the amplifier 34 is controlled by this drive angle signal, and each drive coil 2A, 2B, 2C has an optimized phase. The drive current with

As a result, the motor 2 can be driven with high efficiency, and the generation of rotational ripples and whining noises due to drive unevenness is suppressed, and high performance is achieved. In particular, as is clear from the above embodiment, the mechanical position shift of the phase angle sensor 4 with respect to the drive coil can be corrected only by adjusting the variable resistance of the tracking circuit 12, so the correction operation is extremely simple and can be performed with high precision. be able to. Furthermore, since the tracking circuit 12 can generate an arbitrary phase shift, it is also possible to adjust the driving force of the motor 2 using this phase shift.

In the embodiment, a three-phase motor is used as an example, and the drive angle signal generation circuit generates a drive angle signal with a phase distribution of 120 degrees, but the present invention is not limited to such drive angle signal generation. do not have. Further, although the embodiments have described the case where a single phase angle sensor is used, the present invention is also applicable to the case where several phase angle sensors are used.

Furthermore, as shown in FIG.
C' and each drive coil 2A and 2C or 2
An appropriate drive angle can also be obtained by switching A' to 2C' based on the phase setting signal of the tracking circuit 12 to correct the deviation in the installation position of the phase angle sensor 4 with respect to the drive coils 2A to 2C. be.

As explained above, according to the present invention, the error in the mounting position of the phase angle sensor with respect to the drive coil can be adjusted within the drive current control system, making the adjustment easy and highly accurate. This makes it possible to drive the motor with high efficiency and improve its performance.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a conventional drive control device for a motor, FIG. 2 is an explanatory diagram showing the installation position of a phase angle sensor with respect to a drive coil, FIG. 3 is a block diagram showing an embodiment of the present invention, and FIG. 5 and 5 are explanatory diagrams showing its operation, and FIG. 6 is an explanatory diagram showing another embodiment of the present invention. 2... Motor, 2A, 2B, 2C... Drive coil, 4... Phase angle sensor, 10... Waveform shaping circuit (pulse conversion means), 12... Tracking circuit,
16...first sawtooth wave generation circuit, 18...first
sample hold circuit, 20... voltage divider circuit (level conversion means), 24... comparator (voltage comparison circuit), 26... drive angle signal generation circuit, 36...
...Second sawtooth wave generating circuit, 38...Second sample and hold circuit, 40...Voltage dividing circuit, 54...
drive circuit.

Claims (1)

[Scope of Claims] 1. Pulse conversion means for converting into pulses a phase angle detection signal generated by a phase angle sensor installed on a motor in accordance with the rotation of the motor; A first sample and hold circuit is installed that holds the sawtooth wave voltage obtained from the first sawtooth wave generation circuit that generates the sawtooth wave voltage in synchronization with the pulse, and Voltage comparison in which the held voltage held by the sample and hold circuit is level-converted and taken out via a level variable means, and the level-converted held voltage is compared with the sawtooth wave voltage of the first sawtooth voltage generation circuit. a tracking circuit for generating pulses through the voltage comparison means; and a second sawtooth wave generating circuit for generating a sawtooth voltage in synchronization with the pulses obtained from the tracking circuit. A second sample and hold circuit is installed to hold the sawtooth wave voltage in synchronization with the pulse, and a voltage divider circuit is installed to divide the held voltage held by the second sample and hold circuit at a fixed ratio. a drive angle signal generation circuit that generates a plurality of drive angle control signals having a specific phase by combining the voltage obtained through the voltage dividing circuit and the sawtooth wave voltage; A drive current corresponding to the holding voltage of the second sample and hold circuit is individually caused to flow through the drive coil, and the drive current is applied to each of the drive coils according to the drive angle control signal generated by the drive angle signal generation circuit. A motor drive control device comprising: a drive circuit that selectively switches between;