JP2009277043A - Numerical control system communicating with a plurality of amplifiers in different communication cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To communicate with a plurality of amplifiers in a different communication cycle capable of acquiring feedback data in the cycle shorter than the communication cycle of a drive source having a long communication cycle. <P>SOLUTION: A numerical control system comprises motors 23, 32, amplifiers 2, 3, and a numerical control device 1, and the numerical control device 1 and the amplifiers 2, 3 are coupled by communication lines L1, L2 for data communication in a plurality of different communication cycles. Communication control circuits 12, 14 have receiving buffers 12A, 14A for storing the received data, and refer to position information or speed information of the main shaft motor 23 to control the position or the speed of the feed shaft motor 32. A first amplifier 2 for driving the main shaft motor 23 via the communication line L1 inserts a plurality of pieces of position information or speed information of the main shaft motor 23 sampled at a cycle shorter than a first communication cycle into transmission data to be transmitted at a first communication cycle for the numerical control device 1, and the numerical control device 1 controls the feed shaft motor 32 on the basis of the information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a numerical control device that controls a machine tool, a robot, a press machine, an injection molding machine, or the like that processes a workpiece, and a spindle amplifier and a feed shaft that are connected to the numerical control device through communication lines, respectively. The present invention relates to a numerical control system having an amplifier.

  In high-precision tapping, the rotation of the main shaft and the feed shaft of the drilling shaft are controlled so as to synchronize, and the speed at the time of deceleration and acceleration at the bottom of the hole is matched. The spindle is controlled by a spindle processor that controls the spindle of the numerical controller 1, and the feed axis processor acquires position information and speed information of the spindle and reflects them in the feed axis control command. For this reason, the shorter the feedback data acquisition cycle and the command cycle to the drive source, the higher the synchronization.

  In Patent Document 1, there are multiple drive sources (motors) for applications that synchronize the rotation axis and the feed axis, such as screw machining and tapping, and applications that synchronize a plurality of feed axes, such as tandem machining. It is necessary to synchronize, and feedback data such as position information and speed information of one or more driving sources (motors) is fed back to the control device, and a synchronization error and correction data are calculated from the feedback data by the processor. The technique of reflecting in the command value of this drive source (motor) is disclosed.

  FIG. 8 shows a tapping process in a numerical control system including a numerical control device 1, a spindle amplifier 2 with a slow update cycle, and a feed axis amplifier 3 with a fast update cycle connected to the numerical control device 1 through communication lines. Is a schematic block diagram of a system using a drilling feed axis with an early update cycle and a spindle with a slow update cycle.

  The spindle data update cycle is slower than that of the feed axis because, as shown in FIG. 8, the spindle amplifier 2 side also includes a control processor, so This is because it is necessary to transmit and receive many types of data. Instead, since a control processor is provided on the main shaft amplifier 2 side for control, there is no problem even if the update period of the command data from the numerical control device 1, the position of the main shaft, and the speed information is somewhat delayed. On the other hand, the feed axis does not have a processor on the feed axis amplifier 3 side, so the number of data to be handled is relatively small compared to the spindle, but the commands and position information for axis control are faster than the spindle. It is necessary to send and receive at the update cycle.

  FIG. 9 is a time chart of the timing of obtaining received data from the spindle amplifier 2 and the execution of the command value calculation by the feed axis processor. As shown in FIG. 9, the data from the spindle amplifier 2 has a slower update cycle than the command value calculation cycle of the feed axis amplifier 3, so the position of the spindle amplifier 2 that can be used for feed axis command calculation The speed information must use old data over time, which is disadvantageous for precise synchronous operation of the spindle and the feed axis.

  As shown in FIG. 10, there is a technique for connecting an input device to a communication line with an early update cycle and inputting spindle position / speed information to the input device 4 in order to precisely perform synchronous operation. Since the input device 4 and the feed axis are connected to the same communication line with the fast update cycle, the spindle position and speed data can be obtained at a fast cycle, and synchronous control is possible.

  FIG. 11 is a time chart of the acquisition timing of the spindle position and speed information received from the input device 4 and the execution of the command value calculation by the feed axis processor. In the technique for calculating the data update and the command value at the update cycle shown in FIG. 11, it is necessary to add an input device to the communication line with an early update cycle as shown in FIG. There is a disadvantage of increasing the communication load.

Japanese Patent Laid-Open No. 2007-4068

  When multiple drive sources are connected to a communication line with different communication cycles and feedback data from a drive source with a long communication cycle is reflected in the command value of the drive source with a short communication cycle, a synchronization error or command value There is a problem that the reflection period is limited to a long communication period.

  In order to avoid this problem, there is a technique in which an input device with a short communication cycle is connected, feedback data with a long communication cycle is input to the input device, and feedback data is acquired with a short communication cycle. Such a technique requires additional input devices, which complicates the control system and increases costs.

  Therefore, the present invention incorporates feedback data into the communication data sent in a long communication cycle between the numerical control device and the motor drive amplifier in a time-sharing manner so that the apparent communication cycle of position information and speed information. Different communication that can obtain feedback data in a cycle shorter than the communication cycle of the drive source having a long communication cycle by providing a mechanism that can read and transfer the feedback data every time the feedback data is received. To provide a numerical control system capable of communicating with a plurality of amplifiers in a cycle.

  The invention according to claim 1 of the present application includes a plurality of motors, a plurality of amplifiers that drive the motors, and a numerical control device that controls the motors, and the numerical control devices and the plurality of amplifiers are different from each other. Coupled by a communication line that communicates data in a communication cycle, the communication line is controlled by a communication control circuit built in the numerical controller and the amplifier, and the communication control circuit has a buffer for storing data received by communication In a numerical control system that controls the position or speed of one or more second motors by referring to the position information or speed information of one or more first motors, via the communication line Then, the first amplifier that drives the first motor transmits the first communication cycle in the transmission data that is transmitted to the numerical controller in the first communication cycle. A plurality of the position information or speed information of the first motor sampled at a shorter cycle is inserted, and the numerical control device receives the position information or speed information of the first motor of the first communication control circuit. It is a numerical control system characterized by being referred to from a buffer and used for controlling the second motor.

  The invention according to claim 2 is characterized in that the period shorter than the first communication period for performing the sampling is a first division period obtained by dividing the first communication period into a plurality of parts. The numerical control system described in 1.

  According to a third aspect of the present invention, the numerical control system uses the position information or speed information of the first motor in the buffer of the first communication control circuit to make the first communication cycle plural. Motor control command generating means for generating a control command for the second motor at the divided second division cycle, and transfer of the control command to the second amplifier for driving the second motor at the second divided cycle And a numerical control system according to claim 2.

  According to a fourth aspect of the present invention, the position information or speed information of the plurality of first motors inserted at the first division period arrives at the buffer of the first communication control circuit. In synchronization with the first division period, the position information or speed information of the plurality of first motors is transferred from the buffer of the first communication control circuit to the buffer for generating the control command of the second motor. The numerical control system according to claim 1, further comprising a data transfer mechanism that performs transfer.

  According to a fifth aspect of the present invention, a second constant is obtained by multiplying the position information or speed information of the plurality of first motors in the buffer for creating a control command for the second motor by a preset constant. The numerical control system according to claim 1, wherein a motor control command is generated.

  The invention according to claim 6 is characterized in that the first motor is a main shaft motor and the second motor is a feed shaft motor driven in synchronism with the main shaft motor. It is a numerical control system as described in any one.

  According to the present invention, feedback data such as a plurality of spindle positions and speeds acquired by the first amplifier (spindle amplifier) in accordance with the feed axis command update cycle is inserted into data transmitted from the spindle amplifier to the numerical controller. The numerical control system that communicates with multiple amplifiers at different communication cycles that enables precise synchronous operation of the main shaft and the feed shaft without adding any special input device by providing the feed shaft. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the code | symbol which shows each component is provided with the same number about the same structure or the same structure with the figure (FIG. 8 and FIG. 10) explaining this invention and a prior art.

  FIG. 1 is a schematic block diagram showing a first embodiment of a numerical control system according to the present invention. The first embodiment of the present invention includes a numerical control device 1, a first amplifier 2 having a slow update cycle, and a feed axis amplifier 3 having a fast update cycle, which are connected to the numerical control device 1 through communication lines. Numerical control system.

  Reference sign FB is position information or speed information of the spindle motor 23 connected to the first amplifier 2. Symbol Cm2 is a command value for axis control for the feed axis, which is obtained by calculation based on the position information or speed information FB of the spindle motor 23 by the feed axis control processor (for feed axis) 13. . Symbol Im is motor information, and the spindle motor position information or speed information FB fed back from the first amplifier 2 is inserted into the data sent from the communication control circuit 22 to the communication control circuit 12 at any frequency. This is insertion period setting information for setting the above.

  The numerical controller 1 includes a communication control circuit 12 for receiving position information and speed information from a processor (feed axis) 13 for feed axis control and a first amplifier (main axis amplifier) 2 via a communication line, And a communication control circuit 14 for transmitting an axis control command value to the feed axis. Each of the communication control circuits 12 and 14 includes a reception buffer for temporarily storing the transmitted data.

  The first amplifier (spindle amplifier) 2 includes a control processor (for spindle) 21 for driving and controlling the spindle motor 23 and a communication control circuit 22 for transmitting data to the communication control circuit 12 of the numerical controller 1. It has. The processor (for spindle) 21 receives position information or speed information from the spindle motor 23 as feedback information. This position information or speed information is sent to the communication control circuit 22 via the communication control circuit 22 and the communication line L1.

  The feed axis amplifier 3 is operated by the processor (for feed axis) of the numerical controller 1 and receives an axis control command via the communication line L2 by the communication control circuit 31, and drives and controls the motor 32 for feed axis. Since a control processor is provided on the spindle amplifier 2 side for control, there is no problem even if the update period of the command data from the numerical controller 1 and the spindle position and speed information is somewhat delayed. On the other hand, the feed axis does not have a processor on the feed axis amplifier 3 side, so the number of data to be handled is relatively small compared to the spindle, but the commands and position information for axis control are faster than the spindle. It is necessary to send and receive at the update cycle.

  Therefore, the motor information Im is sent to the communication control circuit 22 of the amplifier 2 via the communication line L1, and the period of the position information or speed information fed back from the first amplifier (for main shaft) 2 to the numerical controller 1 is set. It is sufficient if the cycle for inserting the motor information Im is the same as the control cycle of the commanding communication line. For example, the motor information Im may be set in accordance with the update period of the command data that the processor (for the feed axis) 13 commands the feed axis.

  The feed axis control processor (for feed axis) 13 of the numerical controller 1 reads position information or speed information FB of the spindle motor 23 connected to the first amplifier (spindle amplifier) 2 from the reception buffer 12A. The reception buffer 12A of the communication control circuit 12 in the numerical controller 1 is connected to the communication control circuit 22 to which the processor (for main shaft) 21 of the first amplifier (main shaft amplifier) 2 is connected via the communication line L1. Has been. The reception buffer 12A stores position information or speed information FB from a plurality of first amplifiers (spindle amplifiers) sampled at a cycle shorter than the communication line update cycle.

  The processor (for feed axis) 13 acquires the latest information from a plurality of position information or speed information stored in the reception buffer 12A according to the position control period or speed control period for feed axis control, and feed axis motor This is used to calculate an axis control command value for driving 32.

  Next, an example of a time chart of position information or speed information sent from the first amplifier 2 to the numerical control device 1 in the first embodiment will be shown using FIG. A time chart (1) in FIG. 2 represents timing for obtaining feedback data in the first amplifier. The time chart (2) represents the timing at which the reception buffer 12A receives reception data from the first amplifier. The time chart (3) represents speed / position data in the reception buffer 12A from the first amplifier. Time chart (4) represents the execution timing of command value calculation for other amplifiers.

As shown in the time chart (2) of FIG. 2, the arrival timing of data transmitted from the first amplifier 2 (hereinafter referred to as “received data arrival timing”) has occurred due to a busy state of the communication line or an error. May vary depending on how busy the case is. Due to such variation, variation occurs in the reception data arrival timing of the data arriving at the reception buffer 12A (see FIG. 1) of the numerical controller 1.
If the processor (for feed axis) 13 that controls the feed axis directly refers to the position information or speed information stored in the reception buffer 12A, the same position information or speed information may be referred to depending on the timing of reference. There is. For example, in FIG. 2, the speed / position data (03) in the reception buffer from the first amplifier shown in the time chart (3) is different from the other in two update periods (control periods) shown in the time chart (4). It is used to execute a command value calculation for an amplifier (for example, feed axis amplifier 3).

  In the first embodiment (see FIG. 1), it is possible to share motor position information and speed information between amplifiers having different data update periods. There is a possibility that the data arrival time in the reception buffer may vary (see FIG. 2) due to a re-transmission request when an error occurs or an error occurs, and the processor (for feed axis) 13 that controls the feed axis directly receives the receive buffer 12A. When the position information and speed information, which are feedback information FB from the first amplifier 2, are referred to, the speed of the spindle appears to fluctuate due to variations in data arrival time, and precise synchronous operation becomes difficult.

  Therefore, in the second embodiment of the present invention, as shown in FIG. 3, the speed information or position from the first amplifier 2 is synchronized with the data transfer cycle of the first amplifier 2 and the communication line. A data transfer mechanism 15 that transfers speed or position data at a constant cycle is provided in a buffer that can be referred to by a processor that controls other amplifiers from a reception buffer at a timing when information always arrives. The configuration of the numerical control system excluding the data transfer mechanism 15 is the same as that of the first embodiment shown in FIG. The data transfer timing of the data transfer mechanism 15 is synchronized with the communication timing of the communication control circuit 22 in the first amplifier 2.

  Reference sign FB is position information or speed information of the spindle motor 23 connected to the first amplifier 2. Reference numeral Cm2 is an axis control command value for the feed axis, which is calculated by the feed axis control processor 13 based on the position information or speed information FB of the spindle motor.

  Next, the operation of the data transfer mechanism 15 will be described with reference to FIG. FIG. 4 is a time chart in the second embodiment of the present invention. Time chart (1) represents acquisition of feedback data in the first amplifier. The time chart (2) represents received data from the first amplifier. Time chart (3) represents speed / position data in the reception buffer from the first amplifier. The time chart (4) represents the data transfer command timing. The time chart (5) represents the speed / position data of the data transfer destination buffer. Time chart (6) represents execution of command value calculation for other amplifiers.

  The arrival timing of received data may vary depending on how busy the communication path is or when an error occurs, and the timing at which data arrives at the receiving buffer 12A may vary.

  Therefore, the data transfer mechanism 15 is readable by the processor (for feed axis) 13 that controls the feed axis from the reception buffer at a fixed period in synchronization with the data transfer period of the communication line and always at the timing when the data transfer is completed. By transferring the speed / position data to the buffer, this data is updated at a constant cycle.

  A processor (for feed axis) 13 that controls the feed axis performs spindle speed data with no speed variation by executing a command value calculation in synchronization with the data transfer cycle of the communication line. Obtainable.

  In FIG. 3, the communication lines connecting the numerical control device 1 to the first amplifier 2 and other amplifiers are shown as completely separate. If the communication protocol is compatible with a plurality of update cycles, it is possible to share the same communication line for connecting the first amplifier and other amplifiers with the numerical control device 1.

  FIG. 5 shows one of the structures of the reception data buffer that is transmitted from the first amplifier 2 (see FIG. 1) that is the main amplifier in the embodiment of the numerical control system of the present invention and is stored in the reception buffer 12A of the numerical control device 1. An example is shown. The reception buffer 12A shown in FIG. 1 stores data for one cycle of the update cycle from the first amplifier. FIG. 5 (1) shows the structure of received data received by the reception buffer in the prior art. FIG. 5 (2) shows the structure of received data received by the reception buffer in the present invention. In FIG. 5, the transfer time is increased by inserting a plurality of feedback data in one update cycle. However, the update of the feedback data is set so as to fall within the one update cycle.

  In the prior art, the received data received from the first amplifier 2 has only one feedback data for one update period as shown in FIG. Therefore, in order to perform precise synchronization control, it is necessary to add the input device 4 to the numerical control system as shown in FIG. On the other hand, in the present invention, the received data received from the first amplifier is subjected to precise synchronization control by inserting a plurality of feedback data for one update period as shown in FIG. 5 (2). Therefore, it is possible to obtain feedback data of an early update period necessary for.

  FIG. 6 is a diagram showing a time chart of the feedback data shown in FIG. 5A received by the reception buffer 12A of the numerical controller 1 in the prior art. In FIG. 6, the time chart (1) shows the update period of the reception data from the first amplifier in the reception buffer 12 </ b> A of the numerical controller 1. Time chart (2) shows the acquisition timing of feedback data in the first amplifier. The time chart (3) shows the timing of the reception data received by the reception buffer 12A of the communication control circuit 12 of the numerical controller 1 from the first amplifier. The time chart (4) shows the execution timing of the command value calculation for another amplifier (feed axis amplifier).

  FIG. 7 is a diagram showing a time chart of feedback data received by the reception buffer 12A of the numerical controller 1 shown in FIG. 5 (2) in the present invention. A time chart (1) in FIG. 7 shows an update period of received data from the first amplifier in the reception buffer 12A of the numerical controller 1. Time chart (2) shows the acquisition timing of feedback data in the first amplifier. The time chart (3) shows the timing of the reception data received by the reception buffer 12A of the communication control circuit 12 of the numerical controller 1 from the first amplifier. The time chart (4) shows the execution timing of the command value calculation for another amplifier (feed axis amplifier).

  In the prior art, the feedback data from the first amplifier is only one in one update period (see FIG. 6 (3)), but in the present invention, a plurality of feedback data is inserted in one update period. (See FIG. 7 (2)). Therefore, feedback data with a shorter update cycle can be used in the calculation of command data for other amplifiers (feed axis amplifiers), and a precise synchronization operation is possible.

1 is a schematic block diagram showing a first embodiment of a numerical control system according to the present invention. In the present invention, it is a timing chart when reception data arrival timing from the first amplifier varies. It is a schematic block diagram which shows 2nd Embodiment of the numerical control system which is this invention. It is an example of the time chart of the data in the 2nd Embodiment of this invention. It is an example of the structure of the reception buffer which a numerical control apparatus receives from 1st amplifier in embodiment of the numerical control system of this invention. It is an example of the time chart of the feedback data in the communication line of a prior art. It is an example of the time chart of the feedback data in the communication line of this invention. It is a general | schematic block diagram of the numerical control system which is a prior art. It is a time chart of the data update in the numerical control apparatus system (FIG. 8) which is a prior art. It is a general | schematic block diagram of the numerical control system which added the input device which is a prior art. It is a time chart of the data update in the numerical control apparatus system (FIG. 10) which is a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Numerical controller 11 Spindle processor 12 Communication control circuit 12A Reception buffer 13 Feed axis processor 14 Communication control circuit 14A Reception buffer 15 Data transfer mechanism 2 Spindle amplifier 21 Spindle processor 22 Communication control circuit 3 Feed axis amplifier 31 Communication control circuit 32 Feed axis motor 4 Input device

Claims (6)

A plurality of motors, a plurality of amplifiers for driving the motors, and a numerical controller for controlling the motors,
The numerical controller and the plurality of amplifiers are coupled by a communication line that communicates data at a plurality of different communication cycles,
The communication line is controlled by a communication control circuit built in the numerical controller and the amplifier,
The communication control circuit has a buffer for storing data received by communication,
In a numerical control system for controlling the position or speed of one or more second motors by referring to the position information or speed information of one or more first motors,
A cycle shorter than the first communication cycle in the transmission data transmitted by the first amplifier that drives the first motor to the numerical control device in the first communication cycle via the communication line. Inserting a plurality of position information or speed information of the first motor sampled in
The numerical control system is characterized in that the position information or speed information of the first motor is referred to from the buffer of the first communication control circuit and used for controlling the second motor.   The numerical control system according to claim 1, wherein a period shorter than the first communication period for performing the sampling is a first division period obtained by dividing the first communication period into a plurality of divisions. The numerical control system uses the position information or speed information of the first motor in the buffer of the first communication control circuit, and uses a second division period obtained by dividing the first communication period into a plurality of parts. Motor control command creating means for creating a control command for the second motor;
Means for transferring the control command to a second amplifier for driving a second motor in the second division period;
The numerical control system according to claim 2.   The position information or speed information of the plurality of first motors inserted in the first division cycle is synchronized with the first division cycle at the timing when each of the position information or speed information arrives in the buffer of the first communication control circuit. And a data transfer mechanism for transferring position information or speed information of the plurality of first motors from a buffer of the first communication control circuit to a buffer for generating a control command for the second motor. The numerical control system according to any one of claims 1 to 3.   Creating a control command for the second motor by multiplying the position information or speed information of the plurality of first motors in the buffer for creating the control command for the second motor by a preset constant. The numerical control system according to any one of claims 1 to 4.   The numerical value according to claim 1, wherein the first motor is a main shaft motor, and the second motor is a feed shaft motor driven in synchronization with the main shaft motor. Control system.

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