JP2680219B2 - Positioning 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 a positioning control device for stopping a spindle of a machine tool or the like at a fixed position.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a configuration of a conventional positioning control device, in which 1 is a CP.
U, ROM, buffer, etc. speed command control device, 2 is a vector control device for controlling the speed of the motor 4 according to the speed command given from the speed command control device 1, and 3 is given from the vector control device 2. A driving circuit for switching a power transistor according to a command value to supply a predetermined current to the motor 4, a motor 5 is attached to the motor 4, and a speed for outputting a sine wave signal having a frequency corresponding to the speed of the motor 4. A pulse generator for detection (hereinafter referred to as PLG for speed detection), 6 is a main shaft attached to the motor 4 via gears, belts, etc., 7 is attached to the main shaft 6, and N pulses and one rotation are included in one rotation. Position detection pulse generator (hereinafter referred to as position detection PLG) that outputs two types of pulse, one pulse (hereinafter referred to as Z-phase pulse), at a certain predetermined position inside A.

Further, 8 is a speed detection counter for counting the output pulses of the speed detection PLG 5, and 9 is a position detection P.
A position feedback counter (hereinafter referred to as position FB. Counter) that counts N pulses output during one rotation of LG7, 10 is an interface buffer for one pulse output during one rotation of PLG7 for position detection,
11 is an orient speed command value that gives a fixed speed command, 12 is a creep speed command value that gives a fixed speed command lower than the orient speed command value 11, 13 is a first deceleration point determination circuit, and 14 is a second deceleration point. It is a decision circuit.

FIG. 5 is a block diagram showing the configuration of the vector control device 2 shown in FIG.
5 is a speed command Wr * given from the speed command control device 1.
And a torque component current calculation unit that calculates a torque component current command Iqs * from the output Wr of the speed detection counter 8, 16 is a secondary magnetic flux pattern calculation that calculates a secondary magnetic flux pattern to be given to the motor 4 from the output Wr of the speed detection counter 8. Part, 17 is 2
The output of the next magnetic flux pattern calculation unit 16 is set to the torque current command I
An excitation component current command unit 18 for varying the qs * value to give an excitation component current command Ids * for causing the motor 4 to generate a secondary magnetic flux. Reference numeral 18 denotes a torque component current command Iqs * and an excitation component current command Ids. * And output W of speed detection counter 8
It is a primary current calculation unit that calculates a primary current command I1 * from r.

Next, the operation will be described. FIG. 6 is a flow chart showing the outline of the processing operation in this apparatus. First, it is judged whether or not the fixed position stop command is ON (S6-
1) If the constant command stop command is not given to the speed command control device 1 (OFF), the speed command control device 1 reads a normal speed command value given from the outside, and uses this as a speed command value Wr * for vector control. It is given to the device 2 (S6-
2). The vector control device 2 performs known vector control to generate a primary current command value I1 * for rotating the motor 4 at a speed commensurate with this command, and supplies a current to the motor 4 through the drive circuit 3 to drive the motor 4. Control the speed.

Next, when a fixed position stop command is input to the speed command control device 1 (ON), the speed command control device 1 reads the orientation speed command value 11 and uses it as the speed command Wr *. 2 (S6-
3). The vector control device 2 accelerates or decelerates the motor 4 (speed N2 in FIG. 7) to a speed corresponding to this command value (S6-4). Then, the speed command control device 1
When the value of the speed detection counter 8 becomes a value commensurate with the speed command value and the Z-phase pulse of the position detection PLG 7 is input through the buffer 10 (S6-5), the falling edge is observed and the position FB. The counter 9 is preset (S6-6).

Next, at the position FB. The value of the counter 9 is subtracted by the output pulse of the position detecting PLG 7, and this value is the value of the first deceleration point determination circuit 13 (hereinafter referred to as the first deceleration point).
When it becomes smaller (S6-7), the speed command path control device 1 reads the creep speed command value 12 by looking at this relationship (S6-8), and gives this value to the vector control device 2. Then, the vector control device 2 decelerates the motor 4 to a speed corresponding to this command value (speed of N3 in FIG. 7).
Let it.

The position FB. The value of counter 9 is the second
When it becomes smaller than the value of the deceleration point determination circuit 14 (hereinafter referred to as the second deceleration point) (S6-9), the speed command control device 1 determines that the position FB. The value of the counter 9 is read as it is as a speed command value (S6-10), and this is output to the vector control device 2. Then, when the value of this counter finally becomes zero, the motor 4 is stopped at a fixed position.

The operation inside the vector control device 2 will now be described. When the difference between the given speed command Wr * and the speed of the motor 4 is small, that is, when the spindle 6 is under a light load, the output of the motor 4 can be small. Therefore, in order to prevent noise and vibration of the motor 4, the excitation component Current calculation circuit 17
Indicates the output of the secondary magnetic flux pattern 16 as the torque current command Iq.
It is made smaller according to the size of s *.

When the motor 4 accelerates or decelerates or when a force is applied to the main shaft 6 by cutting or the like, an exciting current component command is generated so that a secondary magnetic flux sufficient to produce the rated output of the motor 4 can be produced. Ids * increases in accordance with the torque current command Iqs *, but since the secondary magnetic flux gradually increases due to the time constant of the motor 4 and the time constant of the excitation current calculation unit 17, immediately after starting acceleration / deceleration. In some cases, the secondary magnetic flux is insufficient, a predetermined output cannot be obtained, and acceleration / deceleration may be slightly delayed.

Therefore, when the fixed position stop is performed, when the speed is sufficiently faster than the orientation speed, the motor 4 is moved to 2
The secondary magnetic flux increases during deceleration, but when the operation is performed from around the orientation speed, the fixed position stop operation is performed while the secondary magnetic flux is insufficient, as shown by the alternate long and short dash line in FIG. 7.

In addition, there is a "servo motor drive monitoring device" disclosed in Japanese Patent Application Laid-Open No. 3-70487 as a reference technical document related to the present invention.

[0013]

Since the conventional positioning control device is constructed as described above, if the spindle is to be smoothly stopped at the fixed position, the fixed position stopping operation is performed from the vicinity of the Orient speed. The deceleration point must be determined, and if the fixed position stop is performed from a speed that is sufficiently faster than the Orient speed, the time to turn at the creep speed becomes longer,
There is a problem in that the time to stop at the fixed position becomes long and the fixed position stop operation is not performed properly.

If the first deceleration point is determined to perform the fixed position stop operation from a sufficiently high speed, when the fixed position stop operation is performed from the vicinity of the orientation speed, the spindle will once pass the target position too much. As a result, there is a problem that the fixed position stopping operation is not properly performed and it takes unnecessary time.

The present invention has been made in order to solve the above problems, and obtains a positioning control device capable of performing a smooth fixed position stop operation regardless of the speed of a motor. The purpose is to

[0016]

The positioning control device according to the present invention is characterized in that the secondary magnetic flux when performing the fixed position stopping operation is increased by switching from the normal magnetic flux.

Whether or not the vector control means outputs an exciting current command sufficient to give a rated output to the motor in response to a signal for switching the secondary magnetic flux from the switching means to complete positioning at the target stop position. After confirming, the value of the excitation current command is returned so as to be reduced according to the magnitude of the torque current command.

[0018]

In the positioning control device according to the present invention, the secondary magnetic flux during the fixed position stopping operation is sufficiently increased, so that the fixed position stopping operation can be performed smoothly and in the shortest time regardless of the speed of the motor. You can

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a positioning control device according to the present invention, in which 1 is a CPU, R
Speed command control device composed of OM, buffer, etc., 2 is a vector control device for controlling the speed of the motor 4 according to the speed command given from the speed command control device 1, and 3 is a command value given from the vector control device 2. A drive circuit for switching a power transistor to supply a predetermined current to the motor 4, a motor 4 and a motor 5 attached to the motor 4 for speed detection for outputting a sine wave signal having a frequency corresponding to the speed of the motor 4. PLG, 6 is a spindle attached to the motor 4 via gears, belts, etc., 7 is attached to the spindle 6, and N pulses per revolution and one Z-phase pulse at a predetermined position during one revolution. A position detecting PLG that outputs two types of pulses.

Further, 8 is a speed detection counter for counting the output pulses of the speed detection PLG 5, and 9 is a position detection P
Position FB.N which counts N pulses output during one rotation of LG7. Counter 10 is 1 of PLG 7 for position detection
An interface buffer for one pulse output during rotation, 11 is an orientation speed command value that gives a certain fixed speed command, 12 is a creep speed command value that gives a fixed speed command lower than the orientation speed command value 11, 13 Is a first deceleration point determination circuit, and 14 is a second deceleration point determination circuit. Reference numeral 19 is a secondary magnetic flux switch.

Next, the operation will be described. FIG. 2 is a flowchart showing the operation of this embodiment. In the flowchart shown in FIG. 2, it is determined whether or not the fixed position stop command is ON (S2-1), and when the fixed position stop command is not given to the speed command control device 1 (OFF), the speed command control device 1 Reads the normal speed command value given from the outside, and uses this as the speed command value Wr *
(S2-2). The vector control device 2 performs known vector control to create a primary current command value I1 * for rotating the motor 4 at a speed commensurate with this command, and supplies a current to the motor 4 through the drive circuit 3 to speed the motor 4. To control.

Next, when a fixed position stop command is input to the speed command control device 1 (ON), the secondary magnetic flux switching device 1
A signal for switching the secondary magnetic flux is given to the vector controller 2 from 9 and the exciting current component Ids * sufficient for giving the rated output to the motor 4 is calculated and outputted by the exciting current calculator 17 (S2- 3). In addition, the speed command control device 1
Reads the orientation speed command value 11 and gives it to the vector controller 2 as a speed command Wr * (S2-
4). The vector control device 2 accelerates or decelerates the motor 4 (speed of N2 in FIG. 3) to a speed corresponding to this command value (S2-5). Then, the speed command control device 1
When the value of the speed detection counter 8 becomes a value commensurate with this speed command value and the Z-phase pulse of the position detection PLG 7 is input through the buffer 10 (S2-6), the falling edge is observed and the position FB. The counter 9 is preset (S2-7).

Next, the position FB. The value of the counter 9 is subtracted by the output pulse of the position detection PLG 7, and this value becomes smaller than the value of the first deceleration point determination circuit 13 (S2-
8), the speed command path control device 1 reads the creep speed command value 12 by looking at this relationship (S2-9) and gives this value to the vector control device 2. Then, the vector control device 2 decelerates the motor 4 (speed of N3 in FIG. 3) to a speed commensurate with this command value.

The position FB. The value of counter 9 is the second
It becomes smaller than the value of the deceleration point determination circuit 14 (S2-1
0), the speed command control device 1 moves the position FB. The value of the counter 9 is read as it is as a speed command value (S2-1
1) After that, it is judged whether or not the positioning is completed at the target stop position (S2-12), and after confirming that the positioning is not completed, the excitation current command Ids * is changed to the torque current command Iqs *. By returning to be smaller according to the size of (S2-13), it is possible to perform a fixed position stop in a shortest time even if the fixed position is stopped from any speed. The noise and vibration of the motor 4 can be reduced.

[0025]

As described above, according to the present invention, since the secondary magnetic flux during the positioning stop operation is sufficiently increased, the fixed position stop can be performed smoothly from any speed and in the shortest time. Can perform an action. Further, the noise and vibration of the motor after stopping at the fixed position can be reduced as usual.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a positioning control device according to the present invention.

FIG. 2 is a flowchart showing the operation of the positioning control device shown in FIG.

3 is a graph showing the movement of the motor when the positioning control device shown in FIG. 1 stops at a fixed position.

FIG. 4 is a block diagram showing a configuration of a conventional positioning control device.

5 is a block diagram showing a configuration of the vector control device shown in FIG.

6 is a flowchart showing an operation of the positioning control device shown in FIG.

FIG. 7 is a graph showing a movement of a motor when a conventional positioning control device stops at a fixed position.

[Explanation of symbols]

 1 speed command control device 2 vector control device 3 drive device 4 motor 5 speed detection PLG 6 spindle 7 position detection PLG 8 speed detection counter 9 position FB. Counter 10 Interface buffer 11 Orient speed command value 12 Creep speed command value 13 First deceleration point determination circuit 14 Second deceleration point determination circuit 15 Torque component current calculation unit 16 Secondary magnetic flux pattern calculation unit 17 Excitation component current calculation unit 18 1 Secondary current calculator 19 Secondary magnetic flux switch

Claims (2)

(57) [Claims] 1. A positioning device having a rotary shaft mechanically attached to a motor and position detecting means for detecting the position of the rotary shaft, and for stopping the motor at a predetermined fixed angle. A positioning control device, characterized in that the control device comprises switching means for switching the secondary magnetic flux to a predetermined value during a fixed position stopping operation. 2. A rotary shaft mechanically attached to a motor, and position detection means for detecting the position of the rotary shaft,
Speed command control means for outputting a speed command, vector control means for controlling the speed of the motor based on the speed command output from the speed command control means, and a predetermined secondary magnetic flux only during the fixed position stop operation. In a positioning control device that has a switching means for switching to a predetermined value and stops the motor at a fixed position at a predetermined angle, the vector control means uses a signal for switching the secondary magnetic flux from the switching means. Output the excitation current command sufficient to give the rated output to the motor, check whether the positioning is completed at the target stop position, and then change the value of the excitation current command according to the magnitude of the torque current command. Positioning control device characterized by returning to a smaller size.