JP3275148B2 - Motor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a motor control device for controlling the rotation speed of a rotationally driven motor.

[0002]

2. Description of the Related Art As an example, when a rotation control is performed on a motor used for an automatic door or the like, a control device 1 having a configuration described below has been conventionally used. Hereinafter, a control device 1 of a motor 2 having a configuration serving as a basis of the present invention will be described with reference to FIGS. 1, 2, 3, and 5. FIG. 1 is a block diagram showing an electric configuration of a motor control device (hereinafter, a control device) 1 having a basic configuration of the present invention, and FIG.
FIG. 3 is a timing chart showing u, Pv, and Pw.
Is a waveform diagram showing an operation example of the related art and an embodiment of the present invention to be described later, and FIG. 5 is a flowchart for explaining the operation of the related art. FIGS. 1, 2 and 3 are also referred to in the embodiments of the present invention described later.

The control device 1 controls the rotational state of a three-phase motor 2 as an example. The motor 2 is provided with a magnetic pole detecting element 3 such as a hall element for each phase. The change in the magnetic flux density of the rotating magnetic field for each phase of the motor 2 is detected. As a result, the magnetic pole detection element 3 can detect the rotation speed and the rotation direction of the motor 2 and the position in the rotation direction, and as shown in FIGS. The rotation signals Pu, Pv, and Pw (hereinafter, collectively referred to as a symbol P) are output as pulse signals having a frequency corresponding to each other. Rotation signals Pu, Pv, Pw
Have a mutually temporal phase difference ΔT, and the phase difference ΔT
T is an amount that changes according to the rotation speed of the motor 2.

The control device 1 includes, for example, an input / output command signal control unit (hereinafter referred to as a control unit) 4 composed of a microcomputer or the like, and further has a rotation speed at which a position signal P from the magnetic pole detection element 3 is input. The measurement unit 5 is provided. The rotation speed measurement unit 5 includes a counter 6, and as shown in FIGS. 3A to 3C, the rotation signals Pu, Pv,
The count values C11, C12,... (Hereinafter, collectively referred to as C1) of the counter 6 are read out at each of the timings t1, t2,. The counter 6 is reset while being generated and output, and then starts counting up. Hereinafter, similar processing is performed. The rotation speed signal from the rotation speed measurement unit 5 is input to the control unit 4.

[0005] A speed command signal corresponding to the reference rotation speed is separately input to the control unit 5, and based on the rotation speed signal and the speed command signal, a control signal having a characteristic of eliminating a deviation between these signals. Is input to the logic circuit 7, and in the logic circuit 7, a control signal for turning on / off each transistor of the inverter circuit 8 is generated.
Is output to A DC power supply is connected to the inverter circuit 8, and a voltage / current from the DC power supply is modulated by the inverter circuit 8 and supplied to the motor 2. Thus, the motor 2 is controlled to rotate at the reference speed based on the speed command signal.

FIG. 5 is a flowchart for explaining the operation of the prior art. The operation as described above will be described with reference to FIG. In step a1, the control waits for a change in the signal level of the rotation signal P. If the determination in step a1 is affirmative,
In step a2, the motor 2 is set based on the count value C1.
And generates and outputs the rotation speed signal V1. In this generation processing, since the count value C1 is the rotation period 1 / f of the motor 2, the reciprocal f thereof is set as the rotation speed, and the rotation speed signal V1 corresponding to the rotation speed f is output. At step a3, the counter 6 is reset, and at step a4, the counting operation of the counter 6 is started. Hereinafter, the same processing is repeated, the rotation speed of the motor 2 is detected, and the rotation control is performed.

[0007]

In such a prior art, for example, when the motor 2 is locked due to foreign matter biting into a power transmission mechanism for transmitting power from the motor 2 to the automatic door or the automatic door itself. It may be suddenly and forcibly stopped. The above-described generation of the rotation speed V1 in step a2 of the flowchart is not started unless there is a change in the level of the rotation speed signal P. Therefore, in the locked state, the rotation speed measured by the rotation speed measurement unit 5 immediately before the locked state is obtained. The signal V1 is continuously output.

When the rotation speed signal V1 is lower than the reference rotation speed indicated by the speed command signal, control for increasing the rotation speed of the motor 2 is performed.
Is greater than or equal to the reference rotation speed indicated by the speed command signal, control is performed to maintain or decrease the rotation speed of the motor 2. That is, in the above-described related art, it is difficult to reliably perform the control for increasing the rotation speed of the motor 2 even when the motor 2 is locked, and there is a problem in that the operation reliability is low.

The present invention has been made to solve the above problems, and an object of the present invention is to solve the problem when the motor is locked.
An object of the present invention is to provide a motor control device that can reliably realize a process of increasing the rotation speed of a motor and that has improved operational reliability.

[0010]

According to a first aspect of the present invention, there is provided a motor control device based on a rotation signal which is a pulse signal having a frequency corresponding to the rotation speed of the motor from a rotation detection unit provided in the motor. , a motor control device for controlling the rotational speed of the motor, a counter, the rotary Shin
Reset the counter at the timing of the signal level change.
After that, the counting operation is started and the next level of the rotation signal is
Read from the counter at the timing of the
The first count value is defined as the first count value.
A rotation speed measuring unit that generates and outputs a rotation speed signal based on the value, and a rotation speed signal of the motor based on the rotation speed signal from the rotation speed measurement unit and a reference speed signal input from outside. A control unit that outputs a control signal to obtain a reference rotation speed corresponding to the reference speed signal, wherein the rotation speed measurement unit is set in advance without any level change of the rotation signal.
When the measurement cycle has elapsed,
The count value read from the counter is used as the second count value.
The second count value and the previous level change of the rotation signal
Compare the first count value counted when
If the second count value is larger than the first count value,
Generates rotation speed signal based on second count value with large
And output.

[0011]

[Operation] In the motor control device according to the first aspect of the present invention,
Based on a first count value read from a counter provided in a rotation speed measurement unit at each timing of a level change of a rotation signal which is a pulse signal of a frequency corresponding to the rotation speed of the motor from a rotation detection unit provided in the motor. A rotation speed signal is generated and output. In addition, the rotation speed measurement unit starts the counting operation after resetting the counter when outputting the rotation speed signal.

[0012] The control unit, based on the rotation speed signal from the rotation speed measurement unit and a reference speed signal input from the outside,
A control signal is output to set the rotation speed of the motor to a reference rotation speed corresponding to the reference speed signal.

Here, the rotation speed measuring unit calculates the rotation signal.
The predetermined measurement cycle has passed without any level change
Sometimes read from the counter when the measurement period elapses
The count value is used as the second count value, and the second count
Counted when the value and the previous level of the rotation signal changed
The first count value is compared, and the first count value is compared with the first count value.
If the second count value is large, the large second count
A rotation speed signal is generated and output based on the value. Therefore, when the motor is locked by an external factor and a rotation speed signal is not output from the rotation speed measurement unit, the second
Since the rotation speed signal is generated based on the second count value whose count value is larger than the first count value, the larger the second count value equal to the rotation period of the motor, the larger the count value, that is, The rotation speed signal corresponding to the low rotation speed is output from the rotation speed measurement unit. Thereby, the motor control device can perform the process of increasing the rotation speed of the motor, and the operational reliability is improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIGS. 1 to 3 have been described in the section of the related art, and will not be described again. The description will be made with reference to the above-mentioned reference numerals, if necessary. FIG. 4 is a flowchart illustrating the operation of the present embodiment.

Hereinafter, the operation of the control device 1 according to the present embodiment will be described with reference to FIG. In step b1,
The rotation speed measurement unit 5 waits for a predetermined measurement period L, which is a period during which the measurement operation of the counter 6 is performed, to wait. This process is performed in parallel with a process of generating a rotation speed signal V1 associated with a change in the level of the rotation signal P described later. The measurement cycle L is selected in a range sufficiently smaller than the minimum value of the expected rotation cycle of the motor 2.

Accordingly, the measurement start time t0 shown in FIG.
In general, the measurement cycle L elapses earlier than the one rotation cycle of the motor 2 elapses, and the count value C2 of the counter 6 at this time is read in step b2. In step b3, it is determined whether or not the count value C2 exceeds the count value C1 of the counter 6 according to the level change of the rotation signal P. If this determination is affirmative, in step b4, a rotation speed signal V1 is output from the rotation period 1 / f of the motor 2 having the same value as the count value C2 and the reciprocal f thereof as the rotation speed V1 of the motor 2 at that time. Hereinafter, the control unit 4, the logic circuit 7, and the inverter circuit 8 control the rotation speed of the motor 2 as described in the section of the related art.

After step b4, the process proceeds to step b8 where the counter 6 continues to count up without being reset. If the determination in step b3 is negative, the process returns to step b1 and repeats the above-described process.

If the determination in step b1 is negative, the process proceeds to step b5, in which the signal level of the rotation speed signal P has changed as shown in FIGS. 3 (1) and 3 (2) as an example. It is determined whether or not. If the determination in step b5 is negative, the process returns to step b1 and repeats the above-described processing. At time t1 in the example of FIG. 3A, if the determination in step b5 is affirmative, the counter 6 is determined in step b6.
A rotation speed signal V1 of the motor 2 is generated and output based on the count value C11. In this generation processing, as described above, since the count value C11 is the rotation period 1 / f of the motor 2, the reciprocal f is used as the rotation speed, and the rotation speed signal V1 corresponding to the rotation speed f is output.

At step b7, the counter 6 is reset, and at step b8, the counter 6 starts counting up from the count 0. Hereinafter, the same processing is repeated, the rotation speed of the motor 2 is detected, and the rotation control is performed.

In such a control device 1, the motor 2 is locked, for example, by a foreign matter biting into a power transmission mechanism for transmitting power from the motor 2 to the automatic door or the automatic door itself, and suddenly and forcibly. It may be stopped. At this time, the rotation speed signal P does not change in level.

In such a case, as an example, FIG.
When the measurement cycle L has elapsed from the level change time t2 of the rotation signal Pv immediately before the lock state shown in (3),
The judgment at step b1 in FIG.
And the count value C21 of the counter 6 shown in FIG.
Is read. At step b3, the count value C12 which is the count value C1 immediately before the lock state and the count value C2
A determination is made to compare with 1. In the example of FIG. 3, this determination is negative, and the rotation speed V1 based on the count value C21 is determined.
Is not generated, and the process returns to step b1.

At a certain timing, when the judgment at step b1 becomes affirmative, if the count value C22 shown in FIG. 3 read at step b2 exceeds the count value C12, the judgment at step b3 is made. Be positive. At this time, based on the count value C21 which is the count value C2 in step b4, the above-described output processing of the rotation speed signal V1 by the reciprocal thereof is performed. Thereafter, the process proceeds to step b8, where the count-up process is performed without resetting the counter 6.

As described above, as the count value C2 of the counter 6 which is equal to the rotation cycle of the motor 2 increases,
The rotation speed signal V1 corresponding to the large count value C2, that is, the rotation speed signal corresponding to the low rotation speed of the motor 2, is output from the rotation speed measurement unit 5. Thereby, the control device 1 of the motor 2 can perform the process of increasing the rotation speed of the motor 2, and the operational reliability is improved.

The present invention is not limited to the above embodiment, but has a wide range of modifications without departing from the spirit of the present invention.

[0025]

As described above, in the motor control device according to the first aspect of the present invention, when the motor is locked by an external factor and the rotation speed signal is not output from the rotation speed measurement unit, the second count is performed. Since the rotation speed signal is generated based on the second count value whose value is larger than the first count value, the larger the second count value equal to the rotation cycle of the motor, the larger the count value, that is, the larger the count value of the motor. A rotation speed signal corresponding to the low rotation speed is output from the rotation speed measurement unit. Thereby, the motor control device can perform the process of increasing the rotation speed of the motor, and the operational reliability is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of a control device 1 having a configuration serving as a basis of the present invention.

FIG. 2 is a timing chart showing rotation signals Pu, Pv, and Pw.

FIG. 3 is a waveform chart showing an operation example of a conventional technique and an embodiment of the present invention.

FIG. 4 is a flowchart illustrating the operation of the present embodiment.

FIG. 5 is a flowchart illustrating the operation of the related art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 control device 2 motor 3 magnetic pole detection element 4 input / output command signal control unit 5 rotation speed measurement unit 6 counter 7 logic circuit 8 inverter circuit Pu, Pv, Pw rotation signal

Claims (1)

(57) [Claims] A motor control device for controlling the rotation speed of a motor based on a rotation signal from a rotation detection unit provided in the motor, the rotation signal being a pulse signal having a frequency corresponding to the rotation speed of the motor. And a counter, and the timing of the level change of the rotation signal.
To start counting after resetting the counter
And the timing of the next level change of the rotation signal.
The count value read from the counter to the first count.
Rotation speed signal based on the first count value.
A rotation speed measurement unit that generates and outputs a rotation speed of the motor based on the rotation speed signal from the rotation speed measurement unit and a reference speed signal input from the outside. A control unit that outputs a control signal to set the rotation speed to a predetermined value.
When the period has elapsed, the counter
The read count value is set as a second count value, and
When the second count value and the previous level of the rotation signal have changed
The counted first count value is compared, and the first count value is compared.
If the second count value is larger than the default value,
Generates and outputs a rotation speed signal based on the second count value
A control device for a motor.