JPH0511849A - Z signal processing method of digital servo - Google Patents

Abstract

PURPOSE:To increase arithmetic processing except in machine origin setting, increase the precision of a motor driving current, and improve the servo performance by allowing a Z-signal reception inhibition flag to be received and decreasing the frequency of current loop processing corresponding one speed loop signal. CONSTITUTION:A CPU 1 and a feedback processing block 2 consists of a speed loop processing block 22 composed switch 221, a current loop processing block 222(i), a processing block 223(i), a Z signal processing block 224, and a switch 225, an encoder processing block 21, a motor 3, and an encoder 4. When the Z-signal reception inhibition flag indicates Z-signal reception permission, dummy processing is added by the arithmetic processing time of the Z signal and the frequency of current loop processing in single-time speed loop processing is reduced to half; when a Z-signal interruption signal is inputted, the arithmetic processing time of the dummy processing is assigned to the Z-signal processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital servo Z signal processing method.

[0002]

2. Description of the Related Art As shown in the block diagram of FIG. 6, Z signal processing in a conventional digital servo is performed by a CPU 1, an encoder processing block 21 as a feedback processing block 2, and a current loop 222 for calculating a motor drive current.
A processing block 22 for calculating (i) and other processing
3 (i), the Z signal processing block 224 (i) for setting the origin of the machine, and the Z signal reception / prohibition flag output from the CPU 1 enables the Z signal interrupt signal output from the encoder processing block 21. A speed composed of a switch 221 to be invalidated, a signal processing block 224 (i) when the Z signal interrupt signal is valid, and a switch 221 which switches to the dummy processing only for the Z signal arithmetic processing time when the Z signal interrupt signal is invalid. The loop processing block 22 includes a motor 3 to be controlled and an encoder 4 that outputs a signal indicating the position of the motor. Also,
As shown in FIG. 7 which is a timing chart of the arithmetic processing when the speed loop processing is performed once and the current loop processing is performed four times, the current loop processing and the other processing and the interrupt are performed within the PWM triangular wave 1/2 cycle of a constant cycle. The calculation processing time that can execute the Z signal processing is ensured. One cycle of PWM processing is performed four times, and one speed loop processing is executed. Furthermore, the Z signal reception / prohibition flag is permitted to receive the Z signal,
When the Z signal interrupt signal is input, the operation processing time of the normal dummy processing is assigned to the Z signal processing.

[0003]

In the Z signal processing of such a conventional digital servo, the PWM triangular wave 1 is always used.
Since the calculation processing time for performing the Z signal processing within the / 2 cycle is secured as a dummy, a loss occurs in the calculation processing time.

The present invention solves such a problem. When the Z signal reception / prohibition flag is set to enable reception, the number of current loop processes in one speed loop process is reduced to set the mechanical origin. The purpose is to improve the servo performance by increasing the accuracy of the motor drive current by increasing the calculation processing other than the above.

[0005]

In order to solve the above problems, the present invention reduces the number of current loop processes in one speed loop process when the Z signal reception / prohibition flag is set to enable reception, so that the machine origin is reduced. The accuracy of the motor drive current is increased and the servo performance can be improved by increasing the calculation processing other than the time of setting.

[0006]

With this configuration, the processing time of the current loop other than the setting of the mechanical origin can be shortened, the accuracy of the motor drive current can be increased, and the servo performance can be improved. .

[0007]

【Example】

(Embodiment 1) FIG. 1 is a block diagram showing an embodiment of the digital servo Z signal processing of the present invention. In FIG.
CPU 1, feedback processing block 2, encoder processing block 21, current loop processing block 222 (i) for calculating N pairs of motor drive currents, processing block 223 (i) for other calculation processing, and speed once If the group of current loop processing blocks processed in the loop processing prohibits the Z signal interrupt processing by the Z signal reception / inhibition flag output from the CPU 1, it is N.
When the Z signal reception / prohibition flag permits the Z signal interrupt processing, a switch 221 for switching execution of the K group processing, and a Z signal processing block 224 for setting the origin position of the machine. , A switch 2 for enabling the Z signal processing block when the Z signal interrupt signal output from the encoder processing block 21 is enabled / outputted
It comprises a speed loop processing block 22 composed of 25, a motor 3 to be controlled, and an encoder 4 for outputting a signal indicating the position of the motor. Further, FIG. 2 is a timing chart of arithmetic processing when one velocity loop processing and four current loop processing are shown, which shows one embodiment of the digital servo Z signal processing of the present invention. In FIG. 2, when the Z signal reception / prohibition flag is prohibited, current loop processing and arithmetic processing capable of executing other processing are executed at a constant cycle, and speed loop processing is executed once in four times. It Furthermore, Z
When the signal reception / prohibition flag indicates that the Z signal reception is permitted, dummy processing is added for the Z signal calculation processing time, and the number of current loop processing in one speed loop processing is halved.
When the Z signal interrupt signal is input, the arithmetic processing time of the dummy processing is assigned to the Z signal processing. When the Z signal reception / prohibition flag is set to Z signal reception prohibition, the current loop processing is performed four times in one speed loop processing and the arithmetic processing capable of executing other processing is executed.

(Embodiment 2) FIG. 3 is a block diagram showing an embodiment of the digital servo Z signal processing of the present invention. In FIG. 3, a PWM triangular wave generation / synchronization block 226
Generates a PWM triangular wave of a constant cycle that carries the motor drive output current when the Z signal reception / prohibition flag output from the CPU 1 is prohibited, and when the Z signal reception / prohibition flag is permitted, receives the Z signal・ 1 when prohibition flag is prohibited
Generate a PWM triangular wave of / T cycle. The current loop processing block 222 (i), which is executed in synchronization with the PWM triangular wave, and when the Z signal processing is interrupted, the arithmetic processing becomes invalid when the time exceeds one speed loop arithmetic processing time.
The processing block 223 (i) is composed of a speed loop processing block. Further, FIG. 4 is a timing chart of arithmetic processing when one velocity loop processing and four current loop processing are shown showing one embodiment of the digital servo Z signal processing according to the present invention. In FIG. 4, in synchronism with the PWM triangular wave at a constant cycle, the current loop processing and the arithmetic processing capable of executing other processing are executed within the one cycle, and one speed loop processing is performed by the four processings. To be executed. further,
When the Z signal reception / prohibition flag indicates that Z signal reception is permitted, P
The WM triangular wave has a cycle of 1/2, and the amount of decrease in the cycle of the PWM triangular wave is subjected to dummy processing to reduce the number of current loop processing in one speed loop processing to 1/2. At this time Z
When the signal interrupt signal is input, the arithmetic processing time of the dummy processing is assigned to the Z signal processing. Further, when the Z signal reception / prohibition flag is set to Z signal reception / prohibition, an arithmetic process capable of executing the current loop process four times in one speed loop process and the other processes is executed.

(Embodiment 3) FIG. 5 is a timing chart of the arithmetic processing when one velocity loop processing and four current loop processing are shown, showing an embodiment of the digital servo Z signal processing of the present invention. In FIG. 5, when the Z signal reception / prohibition flag is prohibited, the current loop processing and other processing can be executed within 1/2 cycle in synchronization with the maximum / minimum points of the PWM triangular wave at a constant cycle. The calculation process is executed, and the speed loop process is executed once in the four processes. further,
When the Z signal reception / prohibition flag indicates that Z signal reception is permitted, P
The current loop processing and other processing are performed in synchronization with the maximum / minimum 1/2 cycle of the WM triangular wave, and the increased processing time that can be secured is subjected to dummy processing. The number of times the current loop processing is performed is halved. At this time, when the Z signal interrupt signal is input, the arithmetic processing time of the dummy processing is allocated to the Z signal processing. When the Z signal reception / prohibition flag is set to Z signal reception prohibition, the current loop processing is performed four times in one speed loop processing and the arithmetic processing capable of executing other processing is executed.

[0010]

As described above, according to the present invention,
When the mechanical origin is set, the PWM triangular wave cycle is reduced to execute Z signal processing, the PWM triangular wave cycle is increased except when the mechanical origin is set, the current loop processing time is shortened, the accuracy of the motor drive current is improved, and servo performance is improved. It is extremely useful in practice that it can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of Z signal processing according to the present invention.

FIG. 2 is a timing diagram of a first embodiment of Z signal processing according to the present invention.

FIG. 3 is a block diagram showing a second embodiment of Z signal processing according to the present invention.

FIG. 4 is a timing diagram of a second embodiment of Z signal processing according to the present invention.

FIG. 5 is a block diagram showing a third embodiment of Z signal processing according to the present invention.

FIG. 6 is a block diagram showing conventional Z signal processing.

FIG. 7 is a timing chart of conventional Z signal processing.

[Explanation of symbols]

1 CPU 2 Feedback processing block 3 motor 4 encoder 21 Encoder processing block 22 Velocity loop processing block 221 switch 222 (i) Current loop processing block 223 (i) processing block 224 Z signal processing block 225 switch 226 PWM triangular wave generation synchronization block

Claims (3)

[Claims] 1. A motor for driving a machine, an encoder for outputting a Z signal indicating a motor origin position, a signal indicating a movement amount, an interrupt processing of the Z signal when the origin position of the machine is set, and other than the origin position setting. CP that outputs a Z signal reception / prohibition flag that prohibits Z signal interrupt processing when
When U and the Z signal reception / inhibition flag enable the interrupt processing of the Z signal, the Z signal output from the encoder is received to enable / output the Z signal interrupt signal, When the prohibition flag prohibits interrupt processing of the Z signal, Z output from the encoder
An encoder processing block that invalidates the Z signal interrupt signal regardless of the signal, a current loop processing block that calculates N pairs of motor drive currents as a speed loop processing block, and a processing block that performs other arithmetic processing once. Of the current loop processing block / processing block group processed in the speed loop of
When the signal reception / prohibition flag prohibits Z signal interrupt processing, N sets of processing, Z signal reception / prohibition flag is set to Z
When the interrupt processing of the signal is permitted, a switch for switching execution of processing of K groups less than N sets, a Z signal processing block for setting the origin position of the machine, and a Z output from the encoder processing block. A digital servo Z signal processing method comprising a feedback processing block including a switch for enabling the Z signal processing block when a signal interrupt signal is enabled / outputted. 2. A Z signal processing block that is interrupt-processed when an interrupt signal is input, and a certain PWM triangular wave that carries a motor drive output current is generated when the Z-signal reception / inhibition flag is disabled. , When the Z signal reception / prohibition flag is enabled, 1 when the Z signal reception / prohibition flag is set
/ PWM triangular wave generation that generates PWM triangular wave of T cycle
The synchronous block and the current loop processing block, which is executed in synchronization with the PWM triangular wave and is invalidated when the Z signal processing is interrupted and the arithmetic processing becomes invalid when the time exceeds one speed loop arithmetic processing time, The digital servo Z signal processing method according to claim 1, which is configured. 3. A Z signal processing block to be interrupted when an interrupt signal is input, and a PW having a constant cycle at all times.
When the M triangular wave is generated and the Z signal reception / prohibition flag is prohibited, a synchronization signal synchronized with the maximum / minimum points of the PWM triangular wave is generated, and when the Z signal reception / prohibition flag is enabled, P
PWM triangular wave generation / synchronization block that generates a synchronization signal that synchronizes with the cycle of the maximum / minimum point 1 / T of the WM triangular wave, and one speed when the Z signal processing is interrupted and executed in synchronization with the synchronization signal 3. The digital servo Z signal processing method according to claim 2, comprising a current loop processing block in which the arithmetic processing is invalidated when the loop arithmetic processing time is exceeded, and a processing block.