JPS5932802B2 - pulse distribution device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse distribution device that distributes pulses to a servo motor that drives a controlled object, and its purpose is to perform smooth slow-up and slow-down control.

Conventional slow-up/slow-down control is performed by controlling the period of the distribution pulse by changing the charging potential due to charging/discharging of a capacitor.
The slowdown characteristics were adjusted by the time constant of the capacitor and the charging/discharging resistance.

However, the slow-up and slow-down characteristics obtained by this method are not appropriate for the torque characteristics of the servo motor and the response characteristics of the controlled object, and even if the time constant is adjusted, the slow-up and slow-down characteristics do not occur in a short time without causing step-out. It was difficult to do so.

In addition, a method has been proposed in which a computer calculates the interpulse period of the distributed pulse for each pulse and performs linear slow-up and slow-down.This method is less likely to cause step-out than the method using a capacitor. , linear slow-up/slow-down is also not optimal for the torque characteristics of the servo motor and the response characteristics of the controlled object, so it is not possible to perform ideal slow-up/slow-down control, and the maximum frequency of the distributed pulse is Slow-up/slow-down control that extends to high-speed ranges has been impossible because it is limited by the computer's arithmetic processing speed. Furthermore, it has been proposed to perform slow-up/slow-down control by storing speed data corresponding to the position of the controlled object in a storage device inside the computer and reading this speed data every time the controlled object moves a predetermined amount. However, this requires an area for storing speed data in a constant speed state, and the speed data cannot be stored in a small capacity memory.

The present invention has been made in view of this point, and includes a storage means for storing each inter-pulse period of distribution pulses whose period changes gradually in the order of pulse transmission, and an address counter for reading out the inter-pulse period from this storage means. , and a preset counter that counts clock pulses of a fixed period and outputs a distribution pulse when the read period has elapsed, and when changing the speed, the address counter is incremented forward or backward by the distribution pulse output from the preset counter. It is characterized by the following.

In FIG. 1, an embodiment of the present invention will be described below with reference to the drawings, 10 is a numerical control device main body, and this numerical control device main body 10 reads numerical control data provided on a paper tape or the like and performs various processes.

When command data for pulse distribution is given, it outputs a pulse distribution start command PDS and also outputs a command speed F given by the command data. Further, the current position of the controlled object 21 is calculated by reading the distribution pulse CP distributed to the servo motor 20, and the current position of the controlled object 21 is calculated.
1 is in the deceleration region, a deceleration signal SDS is output. Reference numeral 11 is a memory for storing the inter-pulse period of distribution pulses, and as shown in Table 1, this memory 11 has the following information:
Larger values are stored as inter-pulse cycle data at younger memory addresses, and smaller values are stored as inter-pulse cycle data as the memory address becomes larger.

Therefore, if the data of this inter-pulse period is read out in order starting from the zero address and the pulses are distributed at the read out period, slow-up can be performed. Slowdown can be performed by reading data and performing pulse distribution. The rate of change of this inter-pulse period is not uniform with respect to changes in memory address, and is changed in accordance with the torque characteristics of the servo motor and the response characteristics of the controlled object.

That is, servo motors, especially pulse motors ′→! Since the torque decreases as the torque increases, the rate of change in the period of the distribution pulse is made large in the low speed region and small in the high speed region. This prevents more than permissible torque from being applied to the pulse motor during slow-up and slow-down.
A gentle slow-up and slow-down occurs in a short period of time. 12 is an address counter that specifies the address of the memory 11 and reads out inter-pulse period data from the memory 11;
The pulse-to-pulse period of the memory address specified by the address counter 12 is output to the data bus 13.

The inter-pulse cycle data outputted to the data bus 13 is applied to a preset counter 14 and a comparison circuit 15. This preset counter 14 counts the reference clock CLK of a constant period output from the reference clock generation circuit 16, and outputs a distribution pulse when the period read from the memory 11 has elapsed. When the load signal LOAD is output from LOAD, the inter-pulse cycle data output to the data bus 13 is read, and when the AND gate AGl is opened, the read data is subtracted by the reference clock CLK, and when the content becomes zero. It is designed to output a distribution pulse CP. In addition,
The load control circuit 17 is for controlling the operation of the preset counter 14, and is enabled when the distribution start signal PDS is output from the numerical control device main body 10, and the distribution pulse CP is output from the preset counter 14. Every time,
A load signal LOAD is applied to the preset counter 14 to load the inter-pulse period data outputted to the data bus 13 into the preset counter 14, after which the AND gate AGl is opened. The distribution pulse CP output from the preset counter 14 is transmitted to the pulse motor 2.
0, the controlled object 21 is driven at a speed corresponding to the frequency of the distribution pulses CP, and is accurately moved by a distance corresponding to the number of distribution pulses CP.

Further, the distribution pulse CP output from the preset counter 14 is passed through the AND gate AG2 to the AND gate A.
It is given to the input terminals of G3 and AG4, and the AND gate AG
3, given to the input terminal of AG4, AND gate AG3
, AG4 are connected to the subtraction terminal UP and addition terminal DOWN of the address counter 12, respectively. Therefore, by switching the AND gates AG3 and AG4, the address counter 12 adds or subtracts the distribution pulse CP. Of these AND gates AG3 and AG4, a deceleration signal SDS output from the numerical interlocking gear device main body 10 is given to the human input terminal of the AND gate AG3, and a deceleration signal SDS is supplied to the input terminal of the AND gate AG4. is provided via the inverter 11.

Therefore, when the controlled object 21 is located in the acceleration region and the deceleration signal SDS is not output from the numerical control device main body 10, the AND gate AG4 is opened and the ANDRE counter 12 sends out the distribution pulse CP. The address of the memory 11 is specified in order from the zero address to the larger address. Furthermore, when the deceleration start signal SDS is output, the AND gate AG3 is opened, so that the address counter 12 counts 1 every time the distribution pulse CP is sent out.
The address designation of the memory 11 is sequentially changed toward the zero address. The comparison circuit 15 compares the inter-pulse period data read from the memory 11 with the inter-pulse period of the command speed F output from the numerical control device main body 10, and when the two match, the address counter 12 is incremented. When the period between the two pulses matches, it outputs a match signal FQS, and this match signal EQS
is applied to the numerical control device main body 10 and the AND gate AG5.

A deceleration signal SDS is applied to the other input terminal of the AND gate AG5 via an inverter 2, and is open in the acceleration region and constant speed region. Therefore, when the match signal EQS is output from the comparator circuit 15 in the acceleration region, this match signal EQS is inverted by the inverter 3, and the AND gate AG2 is closed, thereby stopping the progress of the ANDRES counter 12. Distribution pulses CP are now sent out at a constant inter-pulse period. On the other hand, when the coincidence signal EQS is given to the numerical control device main body 10, the numerical control device main body 10 controls the distribution pulse CP given to the servo motor 20 from the start of pulse distribution until the coincidence signal EQS is output. The number is stored as the distance that the controlled object 21 moves during slow-up, and the controlled object 21 is specified by numerical control data. When it reaches a position before the end point determined by the amount of movement during slow-up, it outputs a deceleration signal SDS.

When the deceleration signal SDS is output, the output of the inverter I2 becomes 33L'2, and the AND gate AG5 is closed, so that the match signal EQS is no longer applied to the inverter 3, and the AND gate AG2 is opened again. As a result, the distribution pulse CP is applied to the subtraction terminal DOWN of the address counter 12, and slowdown is performed. When the end point is reached, the distribution start signal PDS is no longer sent from the numerical control device main body 10. Next, a pulse distribution operation by the pulse distribution device having the above configuration will be explained.

When the numerical control data for pulse distribution is read by the numerical control device main body 10, a distribution start signal PDS is given to the load control circuit 17, and the command speed F given by the numerical control data is given to the comparison circuit 15. . When the distribution start signal PDS is given to the load control circuit 17,
The load control circuit 17 is enabled, and after outputting the LOAD signal to the preset counter 14, the AND gate AGl
open. Load signal LOAD to preset counter 14
When given, the preset counter 14 reads the inter-pulse period being output to the data bus 13. At the start of pulse distribution, the address counter 12 is reset and its contents are zero, so data 2000 at address zero in the memory 11 is output to the data bus 13 and read into the preset counter 14. Then, when the AND gate AG1 is opened, the preset counter 14 subtracts the inter-pulse period data 2000 by 1 each time the reference clock CLK is applied. Inter-pulse period 20
00 has elapsed and the preset counter 14
When the content of becomes zero, a distribution pulse CP is output. When the distribution pulse CP is output from the preset counter 14, this distribution pulse CP is given to the servo motor 20,
Movement of the controlled object 21 is started. Also, since the AND gates AG2 and AG4 are open at this time, the distribution pulse CP is applied to the addition terminal UP of the address counter 12, and the address counter 12 is incremented. Then, data 1800 at address 1 of memory 11 is read out as an inter-pulse period and output to data bus 13. On the other hand, when the distribution pulse CP is output from the preset counter 14,
Since this is given to the load control circuit 17, the load signal LOAD is given to the preset counter 14 again.
Data 1800 at address 1 is preset in the preset counter 14. When the AND gate AG is opened, the preset counter 14 subtracts the inter-pulse cycle data 1800 every time the reference clock CLK is sent out, and when the content becomes zero, outputs the distribution pulse CP. Since the inter-pulse period in this case is shorter than the previous inter-pulse period, the speed of the distribution pulse CP becomes faster. As for the following,
Each time the distribution pulse CP is output, the address counter 12
is incremented, and the read address of the memory 11 is changed one by one.

As a result, the period of the distribution pulse CP becomes shorter and shorter in accordance with the change in the inter-pulse period stored in the memory 11, and the speed of the distribution pulse CP gradually increases. memory 11
As mentioned above, the pulse-to-pulse period stored in the memory address has a large change rate in the small part of the memory address, and the change rate becomes small as the memory address becomes large.
As shown in FIG. 2, the speed of the distribution pulse CP increases greatly when the servo motor 20 rotates at a low speed with high torque.
As the rotation of the servo motor 20 becomes higher, the rate of increase becomes smaller. Thereby, the controlled object 21 can be slowed up in a short time without applying more than permissible torque to the servo motor 20, and the occurrence of distortion can be prevented. When the speed of the servo motor 20 increases and reaches the command speed F, the inter-pulse period read from the memory 11 and the inter-pulse period of the command speed F match, and this is detected by the comparator circuit 15.

Then, a match signal EQS is output from the comparison circuit 15,
This match signal EQS is applied to inverter IV3 via AND gate AG5. As a result, the inverter I
3 becomes 8L", and the AND gate AG2 is closed. When the AND gate AG2 is closed, the distribution pulse CP is no longer given to the address counter 12, so the increment of the address counter 12 is stopped, and the read address of the memory 11 is becomes constant.

For example, if the inter-pulse period of the speed command F is 78, the increment of the address counter 12 is stopped when the data at memory address 420 is read out. This results in
The preset counter 14 outputs a distributed pulse CP with a frequency corresponding to the command speed F, and the controlled object 21 is moved at a constant speed according to the command speed F. When the controlled object 21 is sent to the deceleration starting point, this is detected by the numerical control device main body 10, and the numerical control device main body 10
A deceleration signal SDS is outputted from.

Then, the output of inverter V2 becomes 6L", and AND gate AG5 is closed. As a result, inverter I
The match signal EQS is no longer applied to the gate 3, and the AND gate AG2 is opened again. Furthermore, when the deceleration signal SDS is output, the AND gate AG4 is closed and the AND gate AG3 is opened. As a result, preset counter 1
The distribution pulse CP output from address counter 1
2 subtraction terminal DOWN, and the address counter 12 is decremented every time the distribution pulse CP is sent out. As the address counter 12 is decremented, the read address of the memory 11 decreases sequentially from address 420 toward zero address. As a result, the inter-pulse period of the distribution pulse CP gradually increases, contrary to the slow-up time. As it gets longer, it slows down.

In this case as well, the rate of increase between pulses is small in the high-speed range where the torque of the servo motor 20 is low, and the rate of increase is large in the low-speed range where the torque is high. You can slow down in a short period of time without causing any distortion. In this way, by storing data on the inter-pulse period that matches the torque characteristics of the servo motor 20 and the response characteristics of the controlled object 21 in the memory 11, rapid slow-up and slow-down can be achieved without causing step-out. It can be carried out.

In addition, since the advance of the add task counter is stopped when the inter-pulse period read from the memory 11 matches the inter-pulse period of the command speed, the slow-up is performed using the common inter-pulse data regardless of the command speed. - Not only can slowdown be performed, but there is no need to store data on the period between pulses while the controlled object 21 is moved at a constant speed. In addition, in the above example,
Although the example has been given in which the controlled object 21 is controlled by the numerical control device main body 10, the pulse generator of the present invention can also be used when manually feeding the controlled object.

In this case, the output of the variable resistor for speed setting may be AD converted to the command speed, or the command speed may be set using a digital switch or the like. In addition, the memory of the above embodiment stores only one set of inter-pulse period data for slow-up/slow-down, but it is possible to store data on a plurality of inter-pulse periods according to the command speed range. Alternatively, the data to be read may be selected depending on the command speed range.

Furthermore, if you want to change the pulse distribution characteristics between slow-up and slow-down, you can store the inter-pulse period data for slow-up and the data for the inter-pulse period for slow-down in separate areas. When doing so, search the area where the slowdown data is stored for a memory address where the same data as the inter-pulse period of the command speed is stored, and read out data in order from this memory address. do it.

As described above, in the pulse distribution device of the present invention, a storage means is provided in which the inter-pulse periods of distribution pulses in slow-up and slow-down are stored in the order of pulse transmission, and the inter-pulse periods stored in this storage means are Since the data is read out in order and pulses are distributed at the read cycle, the slow-up/slow-down characteristics can be arbitrarily changed by changing the data in the storage means.

Therefore, it is possible to perform slow-up and slow-down that are optimal for the torque characteristics of the servo motor and the response characteristics of the controlled object, and it is possible to perform slow-up and slow-down in a short time without causing distortion. In addition, since calculation is not required to determine the pulse inter-pulse period, it is slower and faster than when calculating the inter-pulse period using a computer.
It becomes possible to control the slowdown even in the high speed region. In addition, in the pulse distribution device of the present invention, since the address counter stops advancing when the inter-pulse period read from the storage means matches the command speed, it is possible to This method not only does not require an area for storing the inter-pulse period, but also has the advantage that slow-up and slow-down can be controlled using common data even if the command speed changes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram for explaining a pulse distribution operation. 10... Numerical control device main body, 11...
Memo I812...Address counter, 14...
...Preset counter, 15...Comparison circuit, 16...Reference tally clock generation circuit, 17...
... Load control circuit, 20 ... Servo motor, 21 ... Controlled object, AG, ~AG5 ...
...AND gate, 11-I3...Inverter.

Claims (1)

[Claims] 1. A storage means for storing each inter-pulse period of distribution pulses whose period gradually changes in the order of pulse transmission, an address counter that specifies the address of this storage means and reads out the inter-pulse period stored in the storage means, and a constant period. a preset counter that counts clock pulses and outputs a distribution pulse when the period read from the storage means has elapsed;
A pulse distributing device comprising a control circuit that increments the address counter forward or backward by a distributing pulse output from the preset counter when changing the speed.