JP2019103176A - Multishaft motor control system - Google Patents

Abstract

To provide a control system in which a more strict synchronization can be obtained between a master device and each slave device, and between the slave devices.SOLUTION: A multishaft motor control system 1 includes: a master device 2; and a plurality of slave devices 3 connected to the master device in an individual transmission channel each other, and controlling a plurality of multiple-spindle system motors 5. The master device 2 includes a data transmission part transmitting simultaneously master transmission data MD of a fixed length in a prescribed period to the plurality of slave devices 3. Each slave device 3 includes a control part 21 outputting a control signal CD to each motor 5 by determining control timing on the basis of a count value in a counter 41 counting a count setting value set in accordance with the prescribed period, and adjusting the count setting value on the basis of reception timing of a prescribed bit in the master transmission data MD from the master device 2.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a multi-axis motor control system.

  BACKGROUND Conventionally, there is a control system including a plurality of slave devices connected to a master device by communication lines such as multidrop and daisy chain. Each slave device receives control commands from the master device and executes various controls on the controlled device.

  In such a control system, when synchronization is performed between the master device and the slave device and between the slave devices to perform various control operations, the master device normally transmits synchronization command signals to a plurality of control devices as slave devices. Thereby, synchronization is established between the master device and the slave device and between the slave devices. For example, WO 2008/123272 discloses a communication system for synchronizing a plurality of slave devices using a synchronization frame. Each slave device can synchronize with the master device and synchronize between slave devices based on the received synchronization frame.

International Publication No. 2008/123272

  However, in order to increase the timing accuracy of synchronization between the master device and the slave device and synchronization between the slave devices while taking into consideration propagation delay of the signal, transfer time in the device, etc., the synchronization method using the synchronization command signal is used. In this case, transmission and reception of the synchronization command signal and synchronization between the master device and each slave device and synchronization between the slave devices are not secured until the transmission and reception processing is performed, and synchronization timing with higher accuracy is obtained. There is a problem that it can not be obtained.

  For example, in the case of a multi-axis motor control system that performs processing operation, movement operation, etc. on an object while linking a plurality of motors, the object is highly accurate if the synchronization of the plurality of motors is not strictly taken. Can not process, move, etc.

  Therefore, an object of the present invention is to provide a control system capable of obtaining more precise synchronization between a master device and a slave device and between slave devices.

  A multi-axis motor control system according to one aspect of the present invention includes a master device, and a plurality of slave devices each connected to the master device by a separate transmission line and controlling a plurality of motors of a multi-axis drive system. A multi-axis motor control system, wherein the master device has a data transmission unit that simultaneously transmits, to a plurality of slave devices, first transmission data of a fixed length at a predetermined cycle, and each slave device performs the predetermined A control timing is determined based on a count value in a counter that counts a count setting value set according to a cycle, and a control signal to the motor is output, and a predetermined one of the first transmission data from the master device is output. And a controller configured to adjust the count setting value based on the reception timing of the bit.

  According to the present invention, it is possible to provide a multi-axis motor control system in which tighter synchronization can be obtained between a master device and a slave device and between slave devices.

It is a block diagram which shows the structure of the control system concerning embodiment of this invention. It is a figure for demonstrating the synchronous communication performed between a master and a slave concerning embodiment of this invention. It is a figure which shows the example of a sequence of communication between the master 2 and the slave 3 according to the embodiment of the present invention. FIG. 7 is a diagram for describing a first synchronization method at the start of synchronization according to the embodiment of the present invention. It is a figure for demonstrating the synchronization method after the 2nd time concerning embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of a control system according to the present embodiment.

  The control system 1 includes a master device (hereinafter referred to as a master) 2 for controlling the entire system, a plurality of slave devices (hereinafter referred to as a slave) 3, and a plurality of transmission paths 4 for connecting the master 2 and the plurality of slaves 3. It is comprised including. The plurality of slaves 3 are connected to a plurality of (here, N (N is a positive integer)) motors 5 as controlled devices. Each slave 3 is connected to the master 2 via an individual transmission path 4. The plurality of slaves 3 control the plurality of motors of the multi-axis drive system, and servo-control the motor 5 according to the command from the master 2. Thus, the control system 1 is a multi-axis motor control system.

  Master 2 includes a control unit 11, a storage device 12, and a communication control unit 13. The control unit 11 is configured of a field programmable gate array (hereinafter referred to as an FPGA) or the like.

  The storage device 12 is a relatively large storage device such as a flash memory or a hard disk drive, and stores control programs, software programs such as a management program, various control parameter data, various process data in the control system 1 and the like.

The communication control unit 13 is a control circuit that communicates with the N slaves 3. The communication control unit 13 transmits data based on an instruction from the control unit 11, and outputs the received data to the control unit 11 when the data is received.
The communication control unit 13 has a counter 31. The counter 31 is a counter for counting the count value corresponding to one cycle which is the control cycle TS. One control cycle TS is one cycle.

  The counter 31 stores the count value counted up based on the clock circuit 32 of the master 2. The clock circuit 32 includes a quartz oscillator, and generates a clock signal for counting up the counter 31 from the output signal of the quartz oscillator.

  In the storage device 12 of the master 2, n (here, n is a positive integer) corresponding to the control cycle TS is stored as the count setting value CS, and the communication control unit 13 calculates the count value of the counter 31. When n is reached, it is determined that one cycle has ended, and the counter 31 is cleared to repeat counting so as to restart counting.

  The communication control unit 13 repeats counting up to the count setting value CS of the counter 31, and the control unit 11 determines the timing of the control operation of the multi-axis motor control system while referring to the count value of the counter 31. In other words, the counter 31 is a counter for measuring the control cycle TS in the master 2, that is, the interval time of the control timing.

  As will be described later, the master 2 and the N slaves 3 transmit the master transmission data MD simultaneously for operating the N slaves 3 in synchronization with each other to the N slaves 3, It operates cyclically in the same control cycle TS.

  The master 2 reads out and executes the control program stored in the storage device 12 to generate control command signals for the N slaves 3 while referring to the count value of the counter 31, and transmits master transmission data MD. , And transmitted to the N slaves 3 from the communication control unit 13. The control program is a program for executing processing for causing the N motors 5 to perform predetermined operations synchronized with each other. As the control command, in addition to a command for servo-controlling the motor 5, there is also a command for rewriting / reading internal data of the memory of the slave 3 or the like.

  As described above, in the master 2, the count value of the counter 31 is cleared when it reaches the predetermined count set value CS, and the count is repeated so that the count-up of the counter 31 is resumed again. The master 2 simultaneously transmits master transmission data MD including various signals such as control command signals to N slaves 3.

The master 2 and the N slaves 3 are connected by a network 6 including N transmission paths 4. Each slave 3 is connected to the master 2 in a one-to-one manner by the corresponding transmission path 4. In other words, in the control system 1, the master 2 and N slaves 3 are connected by the star network 6.
Each transmission line 4 comprises a full duplex communication line. Thus, each transmission line 4 has two communication lines 4a, 4b (FIG. 2).

The slave 3 includes a control unit 21, a communication control unit 22, and a drive circuit 23. The slave 3 is a control device that servo-controls the motor 5 connected to the slave 3 according to a control command signal from the master 2.
The control unit 21 is configured by an FPGA or the like, generates a control signal CD according to a control command from the master 2, and outputs the control signal CD to the drive circuit 23.

The communication control unit 22 is a circuit that communicates with the master 2 via the transmission path 4. The communication control unit 22 transmits data based on an instruction from the control unit 21, and outputs the received data to the control unit 21 when the data is received.
The communication control unit 22 has a counter 41. The counter 41 is a counter for counting a count setting value CS set according to the same control cycle TS as the master 2.

  The counter 41 stores the count value counted up based on the clock circuit 42 of the slave 3. The clock circuit 42 includes a quartz oscillator, and generates a clock signal for counting up the counter 41 from the output signal of the quartz oscillator.

  The control unit 21 of each slave 3 outputs the control signal CD to the drive circuit 23 when determining that the control timing of the control cycle TS has come while referring to the count value of the counter 41. The control timing of the control cycle TS is defined by the count setting value CS. As described later, the count setting value CS is adjusted by the count value of the counter 41 at the synchronization reference point. The counter 41 is a counter for measuring a control period, that is, an interval time of control timing in the slave 3.

  The control unit 21 also has a delay amount storage unit 43 that stores delay amount data. The delay amount data is time data for delaying the output timing of the control signal CD in accordance with the characteristics of the motor 5 connected to each slave 3. The delay amount data may be the same or different among the N slaves 3. The delay amount data in the delay amount storage unit 43 can be set and changed from the outside.

Although the control cycle TS of the master 2 and the control cycle TS of the slave 3 must be the same, individual differences in the frequency of the crystal oscillator of the clock circuit 32 of the master 2 and the crystal oscillator of the clock circuit 42 of the slave 3 As a result, the control timing of each slave 3 and the control timing of the master 2 are deviated, and the control timing is also deviated between the slaves 3.
Therefore, if the delay amount data of the delay amount storage unit 43 of each slave 3 is equal for all slaves 3, the output timing of the control signal matches that of the other slave 3 by adjusting the count setting value CS as described later. Control timing is adjusted.
If the delay amount data in the delay amount storage unit 43 differs among the slaves 3, each slave 3 further adjusts the control timing which is the output timing of the control signal according to the delay amount data.

The drive circuit 23 is a circuit that generates a drive signal DS in response to the control signal CD from the control unit 21 and outputs the drive signal DS to the motor 5. The drive circuit 23 outputs a drive signal DS, which is a current signal corresponding to the control signal CD, to the motor 5.
The master 2 simultaneously transmits master transmission data MD including a control command signal to the N slaves 3, and the control unit 21 of the slave 3 responds to the control command signal at the control timing defined by the count setting value CS. The control signal CD is generated and output to the drive circuit 23. Each slave 3 outputs the drive signal DS to the motor 5 at the control timing as the control timing when the count value of the counter 41 reaches the count set value CS.

As described later, the count setting value CS of the counter 41 that defines the control timing is adjusted at the reception timing of the master transmission data MD from the master 2.
(Master-slave communication)
FIG. 2 is a diagram for explaining synchronous communication performed between a master and a slave.

  Master-slave communication is performed cyclically. The master-slave communication is performed such that one reciprocation communication is performed in one cycle defined by the control cycle TS in the master 2. Hereinafter, transmission data transmitted from the master 2 to each slave 3 is referred to as master transmission data MD, and transmission data transmitted from each slave 3 to the master 2 is referred to as slave transmission data SD.

  As described above, the master 2 and the slaves 3 are connected one-to-one via the transmission path 4 and communication is performed by the full-duplex communication method. The transmission of the master transmission data MD from the master 2 is performed via the communication line 4 a of the transmission path 4, and the transmission of the slave transmission data SD from the slave 3 is performed via the communication line 4 b of the transmission path 4. That is, the communication control unit 13 of the master 2 is configured to be able to simultaneously transmit the master transmission data MD to the N slaves 3 under the full-duplex communication scheme.

  Further, as described above, the master 2 simultaneously transmits the master transmission data MD to the N slaves 3. That is, the master transmission data MD is simultaneously transmitted to the N slaves 3 so that the reception timings coincide.

  Further, master transmission data MD is fixed length data, and master 2 cyclically transmits master transmission data MD at a predetermined cycle. Therefore, the communication control unit 13 of the master 2 configures a data transmission unit that simultaneously transmits transmission data of a fixed length to a plurality of slaves 3 in a predetermined cycle.

  The master 2 cyclically transmits master transmission data MD in accordance with its own control timing. The N slaves 3 simultaneously receive from the master 2 master transmission data MD which is fixed length data.

  In each slave 3, the first bit Hb of the master transmission data MD is received first, and the last bit Lb is received last. When the control unit 21 of each slave 3 is notified from the communication control unit 22 that the reception of the master transmission data MD has been started, the master transmission data MD is fixed length data and the communication speed between the master and the slave is also in advance. Since it is decided, the reception timing of the last bit Lb is determined as the control timing based on the timing of the start of reception.

  Specifically, in each slave 3, the count setting value is set such that the control timing matches the synchronization reference point, with the reception end timing of the last bit Lb (that is, the reception end data position) as the synchronization reference point rp of the control timing. Control timing is set by adjusting the value of CS.

FIG. 3 is a diagram showing a sequence of communication between the master 2 and the slave 3.
When the master 2 operates N motors 5 in cooperation with each other at a predetermined control timing, the master 2 performs master transmission including a control command signal for causing the N slaves 3 to perform such cooperation. Data MD is generated and simultaneously transmitted to N slaves 3. The master 2 simultaneously broadcasts master transmission data MD to N slaves 3 in each cycle, and the N slaves 3 simultaneously receive the master transmission data MD.

The control command signal included in master transmission data MD from the master 2 may be the same for all slaves 3 or may be different among the slaves 3.
After receiving the master transmission data MD by broadcast from the master 2, each slave 3 starts transmission of slave transmission data SD of a fixed length. The slave transmission data SD includes an ACK signal for the master transmission data MD, process data including status data of the motor 5, and the like.

As described above, one round-trip data transmission / reception is performed between the master 2 and each slave 3 in one cycle.
The size (the number of bits) of master transmission data MD and the size (the number of bits) of slave transmission data SD may be the same or different.

  As described above, one cycle is a time in which the slave transmission data SD can be communicated after transmission of the master transmission data MD and transmission of the master transmission data MD. That is, one cycle is a period longer than the time required to transmit two fixed length data between the master 2 and each slave 3.

  For example, master transmission data MD and slave transmission data SD are data of 100 to several hundred bits. Assuming that one cycle length is C (seconds), the total number of bits of data obtained by combining master transmission data MD and slave transmission data SD is B, and the communication speed is S (bits / second), C, B and S are , C> (B / S). C is, for example, several tens of microseconds.

Therefore, the communication speed between the master 2 and each slave 3 is a speed at which the master transmission data MD and the slave transmission data SD can be transmitted and received within one cycle.
In each slave 3, as described later, the control timing is determined based on the reception timing of the master transmission data MD from the master 2, and the drive signal DS is output to the motor 5 at the determined control timing.

The master 2 determines the cycle timing based on the clock circuit 32. In each slave, the timing of the cycle is determined based on the clock circuit 42.
However, since the crystal oscillator of the clock circuit 32 of the master 2 and the crystal oscillator of the clock circuit 42 of each slave 3 have individual differences, control is performed between the master 2 and the slave 3 and between the plurality of slaves 3 Even when trying to match the timing, it is extremely difficult to match the synchronization timing exactly.

  Therefore, in the present embodiment, the count setting value CS of each slave 3 is adjusted based on the reception timing of the master transmission data MD from the master 2 so that the master 2 and the slaves 3 and between the plurality of slaves 3 can be adjusted. Control timing is matched.

  Specifically, when the communication control unit 22 of each slave 3 starts reception of the master transmission data MD, the control unit 21 determines the fall timing of the last bit of the master transmission data MD, and in the next cycle, Adjust control timing.

Next, the synchronization method between the master 2 and the slave 3 will be described.
(Synchronization method)
Each slave 3 controls the motor 5 while communicating with the master 2, but may control the motor 5 independently without communicating with the master 2. In that case, synchronization is not taken among the plurality of slaves 3.

  When not communicating with the master 2, each slave 3 generates a drive signal DS at a set control cycle TS and outputs it to the motor 5. For example, the control unit 21 of each slave 3 detects whether the count value of the counter 41 has become n corresponding to the control cycle TS. n is a value corresponding to the control cycle TS, and is the same as the count set value CS defining one cycle in the master 2.

The master 2 updates the cycle each time the count value of the counter 31 reaches n.
Each slave 3 repeats the count of the counter 41, and when the count value of the counter 41 becomes the count set value CS, the control unit 21 outputs the control signal CD. Therefore, the output timing of the control signal CD is defined by the count setting value CS. That is, in each slave 3, the control timing is determined by the count value of the counter 41 which is counted based on its own clock circuit 42.

Then, when communication with the master 2 is started, the control unit 21 of each slave 3 generates and outputs the control signal CD at control timing synchronized with the control timing of the master 2. First, a synchronization method when communication with the master 2 is started will be described.
(At the start of synchronization)
FIG. 4 is a diagram for explaining a first synchronization method at the start of synchronization.

  When communication is started between the master 2 and each slave 3, the master transmission data MD first from the master 2 is simultaneously transmitted to N slaves 3. Each slave 3 transmits slave transmission data SD to the master 2 in response to the reception of the master transmission data MD.

As shown in FIG. 4, when communication is started between the master 2 and each slave 3 in a cycle C1, the first master transmission data MD is received by the plurality of slaves 3.
The master 2 determines the transmission timing of the master transmission data MD within one cycle based on its own clock circuit 32. As described above, the communication control unit 13 determines the end timing of the one cycle period at the timing when the count value of the counter 31 becomes n which is the count setting value CS. The communication control unit 13 transmits master transmission data MD at a predetermined timing in one cycle.

  Each slave 3 determines the control timing in each cycle based on the count setting value CS. As described above, at the timing when the communication control unit 22 sets the count setting value CS to n and the count value of the counter 41 becomes n, the control unit 21 sets the end timing of the one cycle period as the end timing. Control timing is used. Each slave 3 is cleared of the counter 41 when the count value reaches n until communication with the master 2 is started, and starts counting up again.

  When reception of master transmission data MD transmitted in the first cycle C1 is started, the communication control unit 22 of each slave 3 receives the first bit Hb of the master transmission data MD. The count value of the counter 41 is output to the control unit 21.

  Since master transmission data MD is fixed-length data, control unit 21 calculates count value m of counter 41 at the timing of the trailing edge of last bit Lb from the count value of counter 41 at the time of reception of first head bit Hb. calculate.

  The falling timing of the last bit Lb is the reception completion position (time) of the master transmission data MD in the cycle of the slave 3, and the control unit 21 synchronizes the reception completion position (time) of the master transmission data MD. It is assumed that the reference point rp.

Then, the control unit 21 adds the count value m of the synchronization reference point rp read from the communication control unit 22 to n to obtain an adjustment count value (n + m).
The control unit 21 sets the obtained adjustment count value (n + m) as the count setting value CS. As a result, the control timing of the next cycle is when the count value of the counter 41 becomes (n + m).

That is, each slave 3 sets the count setting value CS in order to align its control timing with the synchronization reference point rp based on the following equation (1).
CS = n + m (1)
As a result, as shown in FIG. 4, each slave 3 changes the count setting value CS based on the synchronization reference point rp determined by receiving the master transmission data MD in the cycle C1 of the master 2.

  As shown in FIG. 4, in the slave 3, the control timing CT11 of the cycle when the first master transmission data MD is received is when the count value of the counter 41 becomes n (count set value CS). The control timing CT12 of the next cycle is when the count value of the counter 41 becomes (n + m).

  As shown in FIG. 4, since the count value is (n + m), the cycle at the first synchronization is extended by one cycle, and the control timing of each slave 3 is the final bit Lb of cycle C3 of master 2. Match the reception timing.

  As described above, after the master 2 and the slaves 3 are first synchronized, the control unit 21 sets the count setting value CS to n for the control timing CT13 next to the control timing CT12. .

As described above, when communication is started between the master 2 and each slave 3, when the master transmission data MD from the master 2 is received, the shift amount between the cycle time of the master 2 and its own cycle time is calculated. The first control timing is synchronized by determining and adjusting the next cycle time based on the amount of deviation.
(After the start of synchronization, synchronization adjustment after the second time)
The master 2 transmits the master transmission data MD every cycle even after the above-described first synchronization adjustment is performed.

  As described above, each slave 3 counts the count setting value (n + m) set by the first synchronization adjustment, the count setting value CS is set to n, and thereafter the cycle of the master 2 and each slave Three cycles match.

  However, as described above, since the crystal oscillators of the clock circuits 32 and 42 have individual differences, it is necessary to adjust the shift amount of the clock due to the individual differences in order to achieve exact control timing synchronization.

  Therefore, after the first synchronization is taken, the control unit 21 increases or decreases the count setting value CS of each slave 3 based on the reception timing of the master transmission data MD when the master transmission data MD is received. , Synchronization of control timings between master 2 and slave 3 and between slave 3.

The details will be described below.
FIG. 5 is a diagram for explaining the second and subsequent synchronization methods.

As described above, the master transmission data MD and the slave transmission data SD are cyclically transmitted and received between the master 2 and each slave 3. The control unit 21 of each slave 3 calculates the falling timing of the last bit Lb from the count value of the counter 41 at the time of reception of the first bit Hb of the master transmission data MD.
When each slave 3 starts communication with the master 2, the communication control unit 22 holds the count value of the counter 41 at the timing when the reception of the last bit Lb of the master transmission data MD ends, and the count setting value CS of the next cycle is Used for calculation.
The counter 41 is reset to 0 after counting up to the count set value CS determined in the previous cycle, and counts up from 0 again.

  The control unit 21 calculates the difference between the count value of the counter 41 at the synchronization reference point rp and n corresponding to the control cycle TS, with the falling timing of the final bit Lb of the master transmission data MD as the synchronization reference point rp. Do.

  In FIG. 5, since the count value of the synchronization reference point rp based on the master transmission data MD transmitted in a certain cycle C11 is n and the difference is 0, the communication control unit 22 of the slave 3 sets the count setting value CS. It has not changed. Therefore, the control unit 21 sets the control timing CT22 of the next cycle as the timing when the count value of the counter 41 becomes n.

Therefore, in the next cycle, the control timing CT22 of the slave 3 is the timing when the count value of the counter 41 becomes n, and the control unit 21 outputs the control signal CD at the timing when the count value of the counter 41 becomes n.
However, as shown in FIG. 5, when the count value of the synchronization reference point rp based on the master transmission data MD transmitted in cycle C12 is m smaller than n, the difference (n−m) is not 0, The control unit 21 changes the count setting value CS for the next control timing CT23.

  In FIG. 5, the count value m of the counter 41 of the synchronization reference point rp is smaller than the count setting value CS (= n). Therefore, the control unit 21 changes the count setting value CS so that the next control timing CT23 becomes a count value smaller than the difference δ between n and m.

  That is, the control unit 21 sets the count setting value CS for the next control timing CT23 based on the following equation (2) in order to align its control timing with the synchronization reference point rp.

CS = n-(n-m) (2)
As a result, as shown in FIG. 5, at the control timing CT23 of the next cycle, the control section 21 of the slave 3 generates the control signal CD at the control timing defined by the count setting value CS of equation (2). Output.

  The control unit 21 performs the same processing in the next cycle, but if the count value k of the counter 41 of the synchronization reference point rp is larger than (n− (n−m)), the next control timing is In the CT 24, a count value which is larger by the difference δ between n and k is set as the count setting value CS which defines the next control timing CT24 as m = −k based on the above equation (2).

  In FIG. 5, since the count value k of the counter 41 at the synchronization reference point rp when the master transmission data MD is received at the synchronization reference point rp of the cycle C13 is m and the difference is 0, the control unit 21 Shows the case where n is set as the count setting value CS that defines the next control timing CT24.

  As described above, the control unit 21 of each slave 3 determines the control timing of the next cycle based on the count value of the counter 41 that counts the count setting value CS set according to the predetermined control cycle TS. Then, the control signal CD to the motor 5 is output, and the count setting value CS is adjusted based on the reception timing of the final bit Lb as a predetermined bit in the master transmission data MD from the master 2. In particular, the control unit 21 adjusts the count setting value CS each time the master transmission data MD is received from the master 2.

  Therefore, each slave 3 compares the communication data completion position of the master transmission data MD from the master 2, that is, the count value of the counter 41 at the synchronization reference point rp with the count value n corresponding to the cycle time, based on the difference. The count set value CS defining the next control timing is adjusted. As a result, the master 2 and each slave 3 can be synchronized, and the control timing between the slaves 3 can be strictly synchronized.

  By setting the delay amount data of the delay amount storage unit 43 of each control unit 21, the output timing of the control signal CD is delayed by the delay amount according to the characteristics of the motor 5 connected to each slave 3 The control signal CD may be output. The delay amount storage unit 43 stores the delay amount with respect to the control timing.

  For example, by setting the delay amount data, the timing of outputting the current signal can be delayed by the delay amount according to the characteristics of the motor 5. Alternatively, N slaves 3 can be operated in a desired order by adjusting the delay amount data of each slave 3.

Furthermore, in place of the above-mentioned equation (2), the following equation (3) may be used.
CS = n-α * (n-m) (3)
This α is a coefficient for adjusting the convergence time until synchronization. For example, by making α smaller than 1, fluctuation during synchronization adjustment can be reduced.

  As described above, according to the above-described embodiment, it is possible to provide a multi-axis motor control system in which strict synchronization can be obtained between the master device and the slave device and between the slave devices.

  Further, according to the above-described embodiment, master transmission data MD, which is fixed-length data, is transmitted from master 2 to a plurality of slaves 3 every cycle, and accuracy between master 2 and slaves 3 and a plurality of slaves 3 is achieved. According to the above-mentioned system, since each slave 3 transmits slave transmission data SD to the master 2 with fixed length data according to the above-described system, an alarm synchronized with high accuracy is obtained. The master 2 can collect data such as signals and status information. Therefore, each slave 3 can transmit slave transmission data SD including status information on the motor 5 to the master 2 when the master transmission data MD is received.

  Therefore, according to the above-described embodiment, data such as status information stored in the master 2 can be used for more detailed data analysis since it is highly accurate and synchronized data.

  As described above, according to the above-described embodiment, it is possible to provide a multi-axis motor control system capable of obtaining more precise synchronization timing between a master device and a slave device and between slave devices.

  Further, according to the above-described embodiment, each slave device synchronizes control timing with other slave devices while communicating with the master device without using a synchronization frame for synchronization from the master device. Can. In particular, since master 2 transmits master transmission data MD once in one cycle, each slave 3 synchronizes with master 2 in each cycle, so that master 2 and N slaves are synchronized. It is difficult for synchronization deviation to occur between the three.

  In the above-described embodiment, each slave 3 adjusts the count setting value CS each time the master transmission data MD is received. However, for adjustment of the count setting value CS, the master transmission data MD is received twice. It may not be performed every cycle of the master 2 every three times, every three times, etc.

  The present invention is not limited to the above-described embodiment, and various changes, modifications, and the like can be made without departing from the scope of the present invention.

Reference Signs List 1 control system, 2 master device, 3 slave device, 4 transmission path, 4a, 4b communication line, 5 motor, 6 network, 11 control unit, 12 storage device, 13 communication control unit, 21 control unit, 22 communication control unit, 23 drive circuit, 31 counter, 32 clock circuit, 41 counter, 42 clock circuit, 43 delay amount storage unit.

Claims (2)

A multi-axis motor control system, comprising: a master device; and a plurality of slave devices each connected to the master device through individual transmission paths and controlling a plurality of motors of a multi-axis drive system.
The master device has a data transmission unit that simultaneously transmits, to a plurality of slave devices, first transmission data of a fixed length at a predetermined cycle.
Each slave device determines a control timing based on a count value in a counter that counts a count setting value set according to the predetermined cycle, and outputs a control signal to a motor, and the slave device receives the control signal from the master device. A multi-axis motor control system comprising: a control unit that adjusts the count setting value based on the reception timing of a predetermined bit in first transmission data.   The multi-axis motor according to claim 1, wherein each of the slave devices transmits, upon receipt of the first transmission data, second transmission data including status information on the motor to the master device. Control system.

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