JP2000020119A - Multi-axis cooperation control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-axis cooperation control method which can be applied to even a large-scale system, where the number of control axes is large and their controllers are distributed and are arranged a long distance apart, by reducing the number of signal lines. SOLUTION: One of controllers is used as a master M, and the others are used as slaves S1 to Sn. The master and slaves are connected by a communication line L1 for data transmission/reception and an alarm communication line L2 of a daisy chain system. Data of positions of control axes to reference data are stored in slaves S1 to Sn. The master M transmits reference data to slaves at intervals of its own fundamental period, and each slave receives this data to transmit a data reception completion pulse to the communication line L2 at a determined timing. The master M confirms data reception of slaves S1 to Sn by positions of time series of data reception completion pulses. Each slave obtains the phase difference between its own fundamental period and the fundamental period of the master M and corrects received reference data by this phase difference to obtain position data and drives and control the control axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-axis cooperative control method for cooperatively operating a large number of control axes in various industrial machines and various production systems having a large number of control axes.

[0002]

2. Description of the Related Art In a conventional system for performing cooperative control among a plurality of control devices (for example, CNC devices), any one control device serving as a master transmits its reference time (basic synchronization pulse) to a communication line. The data is transmitted to another control device via the control device, and the control device serving as each slave controls each axis in accordance with the basic time from the master. Furthermore, in order to monitor the operation completion of the other party between the control devices that perform the cooperative control,
A dedicated communication line is prepared for each control device, and the operation completion signal of the other party is monitored. For this reason, there is a disadvantage that the number of signal lines of the cable connecting between the control devices is required for the control devices that perform synchronization. In addition, it is necessary to wait until the operation of the other party is completed, and then transmit the next command, which causes a time loss and lowers the operation efficiency.

[0003] Furthermore, there are restrictions on the combinations of control devices that perform synchronization. If the devices A and B and the devices A and C try to execute a synchronous operation at the same time, it is necessary to distinguish the operation completion signals from the device A, the device B or the device C, and the connection order of the devices is also limited. Needed.

[0004]

Accordingly, the present invention reduces the number of signal lines, eliminates the need for transmission of a reference time via a communication line, has a large number of control axes, and the control devices are dispersed and distributed over long distances. It is an object of the present invention to provide a multi-axis cooperative control method that can be applied to a large-scale system that is arranged.

[0005]

According to the present invention, one of a plurality of control units is used as a master unit and the other control units are used as slave units. The slave unit stores data relating to its own axis position with respect to reference data. The master unit and the slave unit are connected by a communication path, and the master unit transmits reference data to each slave unit,
Each slave reads a position corresponding to the received reference data, and in a multi-axis coordinated control method in which a control axis is driven based on the position data to control the position, the communication path is constituted by two communication lines. The master unit simultaneously transmits reference data via one communication line, and upon receiving the reference data, the slave unit transmits a data reception completion signal to the master unit via the other communication line at a predetermined timing. . The master unit determines the received slave unit based on the time-series position of each data reception completion signal sent via the other communication line.

Each slave unit outputs an alarm to the other communication line when an abnormality occurs in each slave unit, and the master unit checks the data reception completion pulse signal in the first half of its own basic cycle. Then, the alarm output is detected in the latter half.
When an alarm is output, the mode shifts from the data communication mode to the configuration mode, and the master unit and the slave unit perform one-to-one communication, and at least status information of the unit where the alarm has occurred is displayed on the display unit of the master unit. To be displayed.

The master unit and each slave unit are controlled by respective basic periods having a common period width,
The master unit transmits the reference data based on its own basic cycle, and the slave unit corrects the received reference data based on the phase difference between the master unit's basic cycle and its own basic cycle, and based on the corrected reference data. Thus, data relating to the position of the control axis of the slave unit is obtained from the table, and the control axis is driven based on the data to control the position, thereby performing a cooperative operation.

[0008]

FIG. 1 is a schematic diagram of an embodiment of the present invention. In the present invention, a master unit (hereinafter, referred to as a master) M and slave units (hereinafter, referred to as slaves) S1 to Sn are connected to a data communication line L1 connected by a party line (N: N) and an alarm signal by daisy chain connection. Is transmitted to the master M, and two serial communication lines of an alarm transmission line. The master M and the slaves S1 to Sn are constituted by substantially the same control devices for controlling the respective axes.
It consists of a C device (computer built-in numerical controller). In FIG. 1, the symbol TM is a terminator. FIG. 3 is a schematic diagram of a control device constituting the master M and the slaves S1 to Sn, and shows an example of an arbitrary slave Si.

In the present embodiment, the control device is constituted by a CNC device, and similarly to a conventional CNC device, a processor 10 for numerical control (CNC), a programmable machine for performing machine sequence control and the like. A bus (21) is connected to a processor (PMC) processor 17 and a servo control digital signal processor (DSP) 19 for controlling the position and speed of a servomotor 28 for driving an axis. Further, the bus 21 includes a CN.
A ROM 11 for storing a system program for the C processor 10; a RAM 12 for temporarily storing data and various setting data and parameters; an interface circuit 13 with an external storage device such as a memory card 23;
A communication interface circuit 14 for connecting to a device or a personal computer 24; a display interface circuit 16 for a CRT, a manual input device with a display device such as a liquid crystal (CRT / MDI) 25; The DO circuit 18 and the communication control circuit 15 are connected.

The DSP 19 for servo control has RA
M20 is connected, and also connected to a position / speed detector 29 such as a pulse coder provided in the servo amplifier 27 and the servomotor 28 for detecting the position / speed of the servomotor 28. The DSP 19 is a CNC processor 1
Position / speed feedback control is performed based on a movement command sent from 0 to the basic cycle (ITP cycle) and a position / speed feedback signal from a position / speed detector. The motor 28 is driven and controlled, and the position and speed of a shaft connected to the servo motor 28 are controlled.

The communication control circuit 15 receives the data transmitted from the data communication line L1 via the receiver 31 and the data transmission unit 15a for transmitting data to the data communication line L1 via the driver 30 and the connector 35. It has a data receiving unit 15b. The data receiving unit 15b
As will be described later, it has a function of determining a mode between a configuration mode and a communication mode and determining an ID code assigned to the control device (slave). The communication control circuit 15 includes an ID storage unit 15c that stores an ID code assigned to its own control device. In addition, the master M also stores the ID code assigned to each of the slaves S1 to Sn in addition to its own ID code.

In addition, the communication control circuit 15 responds to each slave by using the start of data reception from the master M as a trigger.
A pulse generator 15d that generates a pulse indicating that data has been received after a time (corresponding to D). The pulse generated from the pulse generation unit 15d is generated from the downstream slave, is synthesized with the pulse received via the receiver 33 by the synthesizing circuit 15h, and is transmitted to the alarm communication line L2 via the driver 32 and the connector 35. Further, an alarm output unit 15e for asserting the alarm communication line L2 and transmitting an abnormality to the master M when an alarm occurs in its own control device (slave) is provided. Further, a pulse check unit 15f and an alarm detection unit 15g that function only for the master M are provided. Reference numeral 22 denotes a timer which outputs a pulse for each basic cycle (ITP cycle), and the communication control circuit 15 operates in accordance with this cycle.

FIG. 4 is a diagram showing the relationship between transmission and reception of a data reception pulse and an alarm output. The CNC processor 10 of the master M monitors the alarm communication line L2 by dividing it into two within its own basic cycle (ITP cycle). The first half is a pulse detection period, and the second half is an alarm detection period. As described above, each of the slaves S1 to Sn transmits a pulse indicating that it has been received from the pulse generation unit 15d after a time (corresponding to ID) corresponding to each of the slaves S1 to Sn, triggered by the start of data reception. is there. As a result, the master M
Indicates that each slave S is connected to the first half of the basic cycle as shown in FIG.
Pulses indicating data reception from 1 to Sn are received in time series.

Then, as will be described later, when a pulse indicating data reception is not sent from the slave (when a pulse is not received at a time position corresponding to the slave), the master changes the communication mode to the configuration mode. By switching, one-to-one transmission / reception is performed with all slaves, the status of the slaves is checked, abnormalities such as disconnection of the communication line, power supply stages of the slaves, etc. are detected and displayed on the display device 25 of the master M. I have.

If an alarm is output during the pulse detection period, data transmission has already been performed. If data transmission is stopped halfway, a data communication error will occur in all slaves, and the first occurrence will occur. Since it is difficult to identify the alarm that has occurred, the alarm check is not performed in the pulse detection period in the first half of the basic cycle, and the alarm is detected in the latter half of the alarm detection period until the start of the next pulse detection.
Upon detecting the alarm, the CNC processor 10 of the master M immediately changes the communication mode to the configuration mode, obtains the statuses of all the slaves S1 to Sn, and displays the result on the display device 25.

In the present embodiment, as described above,
All slaves S1
There are two modes, a configuration mode for monitoring the state of Sn and a data communication mode for transmitting and receiving data between the master M and the slaves S1 to Sn.

In the data communication mode, the master M transmits reference data for specifying the position of the axis of each slave to each of the slaves S1 to Sn via the data communication line L1 in order to perform a cooperative operation. In the present embodiment, this reference data is referred to as index coordinate position data. Each of the slaves S1 to Sn obtains the position of each axis corresponding to the index coordinate position from the data table held for each slave based on the received index coordinate position data, and drives each axis to that position.

FIG. 2 is an example of a data table set and stored in the master M and the slaves S1 to Sn. In this data table, the slave (or master) that stores the data table has three axes, and also has a signal output axis that outputs a command to each peripheral device.

In the example of the data table shown in FIG. 2, an index coordinate position is defined as a rotation angle, and the positions of the X, Y and Z axes corresponding to each rotation angle are stored. If there is an output signal corresponding to the index coordinate position, the output signal is also stored and output via the PMC 17.
In the example of FIG. 2, the output signal is set to be output between 1.5 degrees and 2.5 degrees of the index coordinate position.

The index coordinate position may be a rotation angle as shown in FIG. 2, a time axis (time is set as an index coordinate position), or a simple linear axis (movement amount index coordinate position). Further, the index coordinate positions may be equally spaced, or a complicated part may be fine, and a part having little change may be a wide data table.

The index coordinate position may be created by a program. The index coordinate position is input to the master M by N / N with respect to a value from a position coder or a position detector from an axis driven by the master M. It may be created by a value multiplied by M (N and M are integer values). Further, an index coordinate position created by a speed command from an external I / O may be used.

In the example of the data table shown in FIG. 2, the slave storing this data table has three axes of X, Y, and Z axes and an output axis for driving external peripheral devices and the like. However, if the slave has only one axis, the data table stores only the index coordinate position and the position of that axis. For example, in the case of a slave having only the X axis in FIG. 2, the data table stores only the rotation angle as the index coordinate position and the X axis position corresponding to this angle. Also,
In the case of a slave that drives only peripheral devices or the like, the data table stores a rotation angle as an index coordinate position in FIG. 2 and a signal output corresponding to this angle.

As described above, the axis operation driven and controlled by the master M or the slaves S1 to Sn is programmed in a data table format based on the index coordinate position. Therefore, this program can be easily created using a personal computer or the like. Data for the master M and each of the slaves S1 to Sn created by a personal computer or the like are collectively taken into the master M, and the master M is transmitted via the data communication line L1.
To a data table for each of the slaves S1 to Sn (a data table formed by index coordinate position data and position data of the axis of the slave corresponding to this position)
Is convenient because there is no need to set a data table for each slave.
In this case, as will be described later, the configuration mode is used to store the data table of each axis position corresponding to the index coordinate position stored collectively in the master M into the ID code specifying the slave and the data of the data table for the slave. , Each slave receives the data table corresponding to its own ID code, and sends back a reception completion signal.

As described above, according to the present invention, the master M and the slaves S1 to Sn own their own data tables, and the master M and the slaves S1 to Sn are based on the index coordinate position data transmitted from the master M. Sn
Performs cooperative control of each axis by drive-controlling its own axis. Therefore, in order to facilitate understanding of the present invention, application examples to which the present invention is applied will be briefly described first.

FIG. 5 is a schematic diagram of an application example to which the present invention is applied. Belt conveyor 40 driven by main shaft
This is an application example in which a liquid is injected into a container 41 moving above. The position of the main shaft that drives the conveyor 40 that transports the container 41 is used as the index coordinate position, and the axis that drives the injector 42 that injects the liquid into the container 41 in a direction parallel to the moving direction of the container 41 (the conveyor 40) is used. The X axis, the axis that drives the injector 42 in the axis direction orthogonal to the X axis is the Y axis, the control devices that drive the X and Y axes are slaves, and the control device that drives the main axis is the master. I do. The Y-axis slave that drives the Y-axis is the injector 42
The solenoid valve which opens and closes the valve is provided.

While the position of the main shaft moves from A1 to A4, the X-axis slave synchronizes with X1 in synchronization with the moving speed of the conveyor.
The X axis is controlled to the position of X4 from
Move in sync with 1. In the Y-axis slave, the main axis is from A1 to A
During the movement to 2, the injector 42 is lowered from Y1 to Y2, and while the main shaft moves from A2 to A3, the solenoid valve is turned on via the PMC 17 to inject the liquid into the container 41. Further, the Y axis is raised from Y2 to Y1 while the main shaft moves from A3 to A4. Also, the main shaft is from A4 to A5
The X-axis slave moves the X-axis from X4 to X
Move to 1. By operating in this way,
As shown in FIG. 5, the liquid is automatically injected into the container 41 while being transported.

A collective data table showing the above-described operation program is as shown in FIG. In the master controller, only a table for storing the spindle position as the index coordinate position is stored as a data table.
The axis slave control device stores a data table that stores data indicating the main shaft position and the X-axis position corresponding to the main shaft position. Further, the control device of the Y-axis slave stores a data table for storing data indicating the main shaft position, the Y-axis position corresponding to this position, and output signal data.

The above is an example of an application order to which the present invention is applied. However, the above description has been made on the assumption that the operations of the axes driven by the master and each slave are completely synchronized. However, the basic cycle of the master (ITP cycle) and the basic cycle of each slave (ITP cycle)
Are running independently. Therefore, receiving the index coordinate position data transmitted from the master M,
The processing time based on this will be different for each slave. A maximum shift of one basic cycle (ITP cycle) occurs between the slaves, and a phase difference occurs between the master and the slave and between the slaves. In addition, omission or skipping of index coordinate position data occurs. Therefore, accurate multi-axis synchronous control cannot be obtained unless these corrections are made.

FIG. 7 is an explanatory diagram of a phenomenon that occurs when a phase shift or the like of a basic cycle (ITP cycle) is not corrected in transmission and reception of index coordinate position data between the master M and the slaves S1 to Sn. The master M transmits index coordinate position data for each basic cycle (ITP cycle) of the master M. Each of the slaves S1 to Sn has a basic period for each slave. In the example shown in FIG. 7, index coordinate position data a1, a2, a3,... Are transmitted for each of the basic cycle start times t0, t1, t2, t3,. ts0, ts
Read out the index coordinate position data a1, a2, a3,... Every 1, ts2, ts3,. However, since each basic period is generated individually, there is a slight shift due to clock variation or the like, and the phase difference changes every moment.
The example of FIG. 7 shows a case where the start time ts2 of the next basic cycle comes before the reception of the data of a2 is completed. If such a phenomenon occurs, the slave cannot receive the data a2. , It will come off. The data read at the beginning of the next basic cycle on the slave side is a3, which means that the data a2 has been skipped.

The time relationship between the index coordinate position data transmitted by the master M and the index coordinate position data received by the slave is as shown in FIG. 7 (b), and a time difference (hereinafter referred to as a phase difference). ) Occurs. In addition, the above-described data loss and skipping occur, and variations in operation occur between the master and the slave and between the slaves.

Each of the slaves S1 to Sn receives the index coordinate position data, and at the start of the next basic cycle, instructs axis movement based on the received data.
The data a1 is read at the start ts1 of the basic cycle of the slave, and at the start ts2 of the next basic cycle, an axis movement command based on this data is output. The other slaves perform the same operation, and the master corresponds to the data a1. Even if the movement command of the axis of the master is started at the start time t2 of the basic cycle of the master M, the start time of the movement command is the phase difference between the master and the slave (t
s2-t2). In other words, a phase difference (tsi-ti) generally occurs between the master and the slave. Further, a phase difference occurs between the slaves due to the shift of the respective basic periods, and it is not possible to perform an accurate cooperative operation.

Therefore, the present invention corrects these and performs an accurate cooperative operation. First, the principle of this correction will be described.

FIG. 8 is an explanatory diagram of the correction principle of the present invention. The index coordinate position data a1 is added to the basic cycle (ITP cycle) starting from time t1 of the master and ending at time t2.
Is sent to the slave. At the slave, it is received during the basic cycle between the start times ts0 and ts1 of the slave.
In FIG. 8, tA is index coordinate position data a1.
Is the transmission completion time, and tB is the reception completion time of the data a1.

Therefore, the phase difference ts1 '= ts1-t1 is obtained.

The time from the completion of data reception tB to ts1 is (ts1-tB) = (ts1-ts0)-(tB-ts0) = T0-(tB-ts0) (1) where T0 is the basic period ( ITP cycle), and since the master M and the slaves S1 to Sn are almost the same, T0 =
ts1−ts0 = t1−t0.

The data transfer time Tt is: Tt = tA-t1 (2) From the above equations (1) and (2), the phase difference ts1 'is ts1' = ts1-t1 = (tB-tA) + Tt + T0- (tB) −ts0) (3)

Therefore, the basic period (ITP) is set for each slave.
A counter C1 is provided to start counting each time a cycle is started, and a latch La for taking in the count value of the counter C1 at the time of completion of reception of index coordinate position data is provided. The time (tB-ts0) is measured by the counter C1 and the latch La. Assuming that the time per count of the counter C1 is k, if the count value taken into the latch La is M, then (tB-ts0) = M × k. Thus, from the above equation, the phase difference ts1 'is expressed by the following equation. Desired.

Ts1 ′ = (tB−tA) + Tt + T0−M × k If this is expressed by a general formula, the phase difference tsn ′ is: tsn ′ = (tB−tA) + Tt + T0−M × k (4) where n = 1, 2, 3, ...

The data transfer time Tt and the basic period T0 are fixed and known times. If the difference (tB-tA) between the completion of data transmission and the completion of data reception is ignored, the latch La
The phase difference tsn 'can be obtained from the value M stored in. That is, the phase difference tsn 'including the error of (tB -tA) can be obtained. Further, the difference (tB-tA) between the completion of data transmission and the completion of data reception is a data transmission delay, which is an experimentally determined time if the system is determined, such as the number of slaves and the length of the cable.
As a result, the phase difference tsn 'of the basic period of each slave with respect to the basic period of the master can be obtained by the counter C1 and the latch La. As a result, each slave can be driven synchronously.

FIG. 9 is a detailed block diagram of the data receiving unit 15b including the counter C1 and the latch La for correcting the above-described phase difference, and the counter C2 used for correcting missing or skipping of data. . Reference numeral 101 in the figure
Receives the data transmitted via the data communication line L1 via the receiver 31, converts the serial data into parallel data, and, based on the special bits of the transmitted data, transmits the data in the configuration mode or the data communication. A data reception / conversion / mode discrimination circuit that discriminates whether the mode is the mode, and further determines the ID code. The circuit 10
When a data reception completion flag F2 (not shown in FIG. 9) provided at 1 is set upon completion of data reception, a data reception completion signal Se is output to the data holding circuit 102, the latch La, and the counter C2. . The circuit 1
01, data and mode converted to parallel data,
The ID determination result is output to the reception data holding circuit 102 and stored. The CNC processor 10 reads out this data and the data of the latch La and the counter C2 described later,
When the reception data read completion signal Sr is output, the reception data holding circuit 102 and the latch La are reset by the signal Sr, and the data reception completion flag F2 is output.
Is also reset, and the data reception completion signal Se disappears.

The counter C1 is reset by a pulse for each basic cycle (ITP cycle) output from the timer 22, and counts clock pulses. The latch La is
When the data reception completion signal Se from the data reception / conversion / mode determination circuit 101 described above rises, the counter C1
Capture the count value of Also, the CNC processor 1
When 0 outputs the received data read completion signal Sr, the latch La is reset.

The counter C2 starts counting the basic cycle (ITP cycle) pulses in response to the data reception completion signal Se from the data reception / conversion / mode discrimination circuit 101, and reads the reception data read completion signal Sr or the next data reception. It is reset by the completion signal Se. That is, the counter C2 receives the data and the data reception completion signal S
When e occurs, counting of a basic cycle (ITP cycle) pulse is started.
The received data is read out based on the (P period) pulse, and the received data reading completion signal Sr is output. Therefore, in FIG. 7, the data a0 and a1 are received and the basic period (ITP period) is received. When the data is read at the pulse times ts0 and ts1, the value of the counter C2 is "1". However, in the case of the data a2 in FIG. 7A, the reception of the data has not been completed before the basic period (ITP cycle) pulse time ts2, and the data reception completion signal Se becomes the basic period (ITP period). Since it has not occurred before the pulse time ts2, the counter C2 has not started counting and remains "0". Therefore, from the value of the counter C2, the CNC processor 10 can know that the data is missing.

As described above, the latch La starts receiving the data reception completion signal S from the generation of the basic cycle (ITP cycle) pulse.
Since the value of the counter C1 at the rising edge of e is stored, the CNC processor 10 multiplies the read value M by the time per count (interval of the clock signal) k (tB in FIG. 8). −ts0) = k · M. Then, the phase difference tsn 'can be obtained by performing the calculations of the above four equations.

Further, based on the value of the read counter C2,
Since it is possible to know whether or not data has been lost, if data has been lost, an index is extrapolated based on the data read in the basic cycle one and two before the cycle and the calculated phase difference. The coordinate position data and the phase difference are calculated. In the example of FIG. 7, when the data a2 cannot be read, the estimated value a2 'of this data and the estimated value ts2''of the phase difference at this time are obtained as follows.

A 2 ′ = 2 × a 1 −a 0 ts 2 ″ = 2 × ts 1 ′ −ts 0 ′ When this is expressed by a general expression, the data estimated value an ′ and the phase difference estimated value tsn ″ are expressed by the following five expressions. , 6

An ′ = 2 × an−1−an−2 (5) tsn ″ = 2 × ts (n−1) ′ − ts (n−2) ′ (6) The equation is for a case of first order approximation.

At time ts3 in FIG. 7, data a3 is read and data a2 is not read. However, as described above, this data a2 is a value a2 estimated by the equation (5) at the timing of time ts2. , There is no problem. At the timing of time ts3, it is sufficient to perform only the calculation of the above-described ordinary four phase difference.

The index coordinate position data an and the estimated value an ′ thus read are stored in a data table corresponding to the index coordinate position data an with reference to the start of the next basic cycle (ITP cycle) of the slave. The movement to the storage location is performed. The master M moves to the position stored in the data table corresponding to the sent index coordinate position data an with reference to the start of the next basic period of the basic period (ITP period) of the master that transmitted the data. Will do. However, as described above, since the basic period of each slave has a phase difference tsn 'with respect to the basic period of the master, this must be corrected. That is, in the example shown in FIG. 7, the master M and the data corresponding to the index coordinate position data a1 stored in the data tables of the slaves S1 to Sn are read by the master M on the basis of the next basic cycle start time t2. FIG. 7 (b) is executed based on ts2 at the start of the next basic cycle.
As shown in (1), since there is a time difference of the phase difference ts2, a positional shift occurs. Therefore, interpolation is performed using the phase difference tsn, the data an read in the cycle, and the data an-1 read in the immediately preceding cycle, and the corrected index coordinate position data asn is obtained by the following equation (7).

Asn = an + [tsn ′ × (an−an−1) / T0] (7) In each slave, the position of the axis of the slave is obtained from each data table based on the corrected index coordinate position data asn thus obtained. And outputs a movement command to each slave axis based on the position.

FIGS. 10A and 10B are diagrams showing the relationship between the sent index coordinate position data an and the corrected index coordinate position data asn. As shown in FIG. 10B, the deviation of the index coordinate position data is almost eliminated, and as a result, accurate multi-axis coordinated control can be performed.

FIG. 11 shows the configuration mode, and FIGS. 12 and 13 show the data communication mode.
It is a flowchart of the process which CNC processor 10 of master M and slaves S1-Sn performs.

At the time of initial setting upon power-on or occurrence of an alarm, the mode shifts to the configuration mode shown in FIG. 11, and the master M and each of the slaves S1 to Sn perform one-to-one communication. First, the operation when the power is turned on will be described. It is assumed that index coordinate position data and a data table indicating the position of each axis are stored in the nonvolatile portion of the RAM 12 of the master M and each of the slaves S1 to Sn. Further, it is assumed that respective ID codes are already set in the respective slaves S1 to Sn, and the ID codes of all the slaves S1 to Sn are stored in the master M.

Therefore, first, when the ID code of the slave performing the synchronous operation is set to the master M and an operation command is given, the CNC processor 10 of the master M starts the processing in FIG.

First, the register SID designating the ID code of the slave is set to "0" (step A1), then the register SID is incremented by "1" (step A2), and the value of the register SID becomes Number of slaves N
Is determined (step A3). If not, it is determined whether the slave of the ID code indicated by the register SID is set as a synchronous operation (step A4). If not set, the process proceeds to step A2. Return.
Thereafter, the register SID is sequentially incremented, and if the ID code indicated by the register SID is set as the ID code of the synchronous operation slave, a specific bit is set to the code of the configuration mode, and is indicated by the register SID. The slave ID code and the synchronization permission code are set in the transmission buffer of the data transmission unit 15A, and the transmission start flag F1 is set (step A5).

Then, it waits for the generation of an ITP pulse output from the timer 22 for each basic cycle (ITP cycle) (step A6), and when this ITP pulse occurs, resets the transmission start flag F1 (step A7) and performs communication. The data stored in the transmission buffer is transmitted from the control circuit 15 via the driver 30, and the CNC processor 10
The response waiting timer T is started (step A8), and it is determined whether or not the slave has responded until the timer T reaches the set time Tu (steps A9 and A10).

On the other hand, the CNC processor 1 on the slave side
0 polls the data reception completion flag F2 provided in the data reception unit 15b in the communication control circuit 15,
It is repeatedly determined whether the flag F2 is set (step B1). When the reception of the data sent from the master is completed and the data reception completion flag F2 is set, the processor 10 sets the reception data holding circuit 10
2 (step B2), outputs a read completion signal Sr, and outputs a data reception completion flag F2,
Received data holding circuit 102, latch La, counter C2
Is cleared (step B3). Next, it is determined from the specific bit of the read data whether the mode is the configuration mode and whether the transmitted ID code matches its own ID code (step B4).

If the mode is not the configuration mode or the slave ID code does not match its own ID code, the process returns to step B1. If the slave ID code read in the configuration mode matches its own ID code, the transmission enable flag F3 is set (step B5), and it is determined whether the received data is normal (step B).
6). If there is an abnormality in the received data due to noise during transmission or the like, a re-request flag F5 is set (step B12),
Proceed to step B7. If there is no abnormality in the received data, step B7 is performed without setting the re-request flag F5.
Go to 7. In step B7, the status data of the slave including the status of the re-request flag F5 is set in the transmission buffer, and the transmission start flag F4 is set. Then, when the first ITP signal is generated after the transmission start flag F4 is set (step B8), the flag F4 is set.
3, F4 and F5 are reset and the data stored in the transmission buffer is transmitted to the master (steps B9 and B9).
10) The polling process of the reception completion flag F2 is started again (step B11).

The CNC processor 10 of the master M determines whether or not there is a response from the slave until the set time Tu elapses from the start of data transmission in steps A9 and A10. Slave flag F (I
D) is set to abnormal ("1") (step A1)
3) Return to step A2.

When there is a response from the slave (corresponding to the processing of step B10 of the slave), the received data is checked (step A11), and if the re-request flag F5 is set or the received data is abnormal. Returning to step A5, the ID code, the configuration mode code, and the synchronization permission code are transmitted again. If there is no abnormality in the received data and the re-request flag F5 is not set, the slave flag F (ID) is set to normal ("0"), the sent status data is held (step A12), and step A2 is performed. Return to

Hereinafter, while incrementing the register SID, the ID code, the configuration code, and the synchronization permission signal are transmitted to the set slave, and the register S
When the ID value exceeds the number N of all the slaves, the status (normal, abnormal, status) of all the slaves held on the display screen of the MDI 25 with the display device is displayed (step A14).

If the start signal is turned on by a program or the like without any abnormality, the mode shifts to the data communication mode, the processing shown in FIGS. 12 and 13 is started, and the synchronous operation is started.

It should be noted that each of the slaves S1 to S
When the data of the data table is transmitted to n, the data of the data table corresponding to the slave ID transmitted in step A5 may be transmitted at the same time.

In the data communication mode, the CNC processor 10 of the master transmits the index coordinate position data to the slave, whether the alarm communication line L2 is asserted, or transmits the index coordinate position data to the slave as described above. It is determined whether the received pulse from the pulse generator 15d is received (step A20).
When the alarm communication line L2 is asserted or when no reception pulse is received from the slave, the mode shifts to the configuration mode shown in FIG. If the alarm has not occurred, the index coordinate position is generated or calculated at the time of interruption every basic period (ITP period), and the index coordinate position data and the ID code of the slave that operates synchronously are set in the transmission buffer. , Sets the transmission start flag F1 (step A2)
1).

When the first ITP signal is received after the transmission start flag F1 is set, the transmission start flag F1 is reset and the index coordinate position data and the like stored in the transmission buffer are transmitted (steps A22 to A24). Return to A20. Hereinafter, the CNC processor 10 of the master M repeatedly executes the processing of the steps A20 to A24 and transmits the index coordinate position data to the slaves that operate synchronously.

On the other hand, the CNC processors 10 of the slaves S1 to Sn execute the processing shown in FIGS. 12 and 13 for each basic cycle (ITP cycle). First, the flag F6 indicating that the synchronous operation is being performed is set to 1. (Step B2)
0) At first, since it is not set in the initial setting and is “0”, the process shifts to step B21 and the reception completion flag F2
Is determined to be ON (“1”), and if not ON, as described above, between the start pulse of the previous basic cycle (the ITP cycle) and the start pulse of the basic cycle (between the previous basic cycle), This means that the index coordinate position data has not been received, and in this case, the processing of the basic cycle (ITP cycle) ends.

On the other hand, when the reception completion flag F2 is ON, the ID data and index coordinate position data and the like held in the reception data holding circuit 102 are read, and the data M stored in the latch La and the value of the counter C2 are read. Read (step B22), read completion signal Sr
(Step B23), and resets the reception completion flag F2, the reception data holding circuit 102, the latch La, and the counter C2.

Next, from the specific bits of the read data,
It is determined whether the mode is the data communication mode and whether there is an own ID code (step A24). If the mode is the data communication mode but there is no own ID code, the process of the ITP cycle ends. If the mode is the configuration mode, the flag F6 is reset to "0" (step B31), and the flow shifts to step B7 in FIG.

If the ID code coincides with the own ID code in the data communication mode, the flag F6 indicating that the synchronous operation is being performed is set to "1" (step B25), and it is determined whether the received data is normal (step B25). B26). If normal, the counter C3 is cleared (step B27), the value M read from the latch La, a preset time k per clock, a basic cycle (ITP cycle) T0, a data communication time Tt, and Is the transmission path delay (TB
-TA), the above equation 4 is calculated to determine the phase difference tsn 'between the basic periods of the master and the slave (step B28).

Next, the obtained phase difference tsn 'is calculated in step B2.
The index coordinate position data an read in step 2, the basic cycle (ITP cycle) T0, and the index coordinate position data a one basic cycle before stored in a register R (a1) described later.
The calculation of equation 7 is performed using n-1 to obtain index coordinate position data asn in which the phase difference of the slave is corrected (step B29). Then, the index coordinate position data an-1 one basic cycle before stored in the register R (a1) is stored in the register R (a2), and the register R (a1) stores step S
The index coordinate position data an in the basic cycle read in B22 is stored. Further, the phase difference tsn-1 one basic cycle before stored in the register R (ts1) is stored in the register R (ts1).
2), and the phase difference tsn 'in the basic cycle obtained in step B28 is stored in the register R (ts1) (step B36).

Then, based on the data table stored in the RAM 12 of the slave, the index coordinate position data asn in which the phase difference obtained in step B29 has been corrected is obtained.
And the movement command is obtained by obtaining the position of the axis of the slave corresponding to (step B37). It is determined whether the moving speed obtained by the moving command exceeds the set limit value of the relevant axis or whether an alarm is generated for the relevant slave (step B38). If it is within the limit value, the movement command amount obtained in step B37 is output to the servo DSP 19 (step B2).
9) The drive of the servo motor that drives the slave axis is controlled, and the processing of the basic cycle ends. If an alarm has occurred or the moving speed has exceeded the limit value, the process proceeds from step B38 to step B40, where the alarm communication line is asserted to terminate the processing of the basic cycle, and Move to mode.

If it is determined in step B26 that the received data is abnormal due to noise or the like, the counter C
"1" is added to 3 and it is determined whether the value of the counter C3 is 2 (steps B32 and B33). If not, the process proceeds to step B34. If “2”, step B
The process shifts to 40 and switches to the figuration mode. That is, if the received data is determined to be abnormal twice consecutively, the alarm communication line is asserted to switch to the configuration mode. When the first received data is abnormal, the received data is ignored and the above-described data missing processing is performed. That is, the registers R (a1), R
The calculation of the above equation (5) is performed from the reception index coordinate position data an-1 and an-2 one before and two before the basic cycle stored in (a2), and the estimated index coordinate position data an 'is calculated. This is determined as index coordinate position data an of the cycle (step B34). In addition, the basic cycle stored in the registers R (ts1) and R (ts2) is 1
The above-mentioned equation (6) is calculated from the phase differences ts (n−1) ′ and ts (n−2) ′ immediately before and two times before to obtain an estimated phase difference tsn ″ in the basic cycle. The cycle phase difference is set as tsn '(step B35), and the flow shifts to step B29.

Once the index coordinate position data has been received, the flag F6 for storing the synchronous operation is set to "1".
The process proceeds to 30, and it is determined whether the value of the counter C2 is "0".
If it is not "0", as described above, it indicates that there is no omission of the received data and the reception is being performed.
Then, the process proceeds to step S2. Also, the counter C2
Is "0", it means that the received data has not been obtained before the start of the basic cycle (ITP cycle), and since data omission has occurred, the process proceeds from step B30 to step B34. Then, the above-described estimated index coordinate position data an ′ and the estimated phase difference tsn ″ are obtained, and the index coordinate position data an obtained by correcting the time interval variation and the phase difference is obtained. Find from the table.

[0073]

According to the present invention, data transmission / reception between the master and a plurality of slaves and reception completion confirmation can be performed with two communication lines, so that the communication line can be disconnected due to an external failure (only one or both of them). ) When the data is received, since the data reception pulse from the slave is not returned to the master, the master can detect the abnormality and stop the data transmission, thereby preventing runaway of the entire system. Further, the master can detect when an alarm occurs in the slave, and the management by the master can be easily performed.

The slave determines the phase difference between the basic periods of the master and the slave, corrects the reference data sent from the master by the phase difference, and uses the corrected reference data to determine the position of the control axis of the slave. Since the control axis is driven by obtaining data, a precise cooperative operation can be performed without causing a positional shift of the cooperative operation between the master and each slave. Further, even if the number of slaves is increased and the number of cooperative axes is increased, the deviation of the reference data due to the phase difference is corrected by the slave itself, so that accurate cooperative operation is possible, and the system can be easily expanded. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a data table in the embodiment.

FIG. 3 is a detailed block diagram of a master and a slave in the embodiment.

FIG. 4 is an explanatory diagram illustrating transmission and reception of a reception pulse and an alarm signal in the embodiment.

FIG. 5 is an explanatory diagram of one application example to which the present invention is applied.

FIG. 6 is a diagram showing an example of a data table of the application example.

FIG. 7 is an explanatory diagram of a basic cycle and an index positional relationship in a master and a slave.

FIG. 8 is an explanatory diagram for obtaining a phase difference between a basic cycle of a master and a slave.

FIG. 9 is a detailed block diagram of a data receiving unit in the communication control circuit according to one embodiment of the present invention.

FIG. 10 is an explanatory diagram of phase difference correction and interval variation correction.

FIG. 11 is a processing flowchart of a master and a slave in a configuration mode.

FIG. 12 is a processing flowchart of a master and a slave in a data communication mode.

FIG. 13 is a continuation of the processing flowchart of the slave in the data communication mode.

[Explanation of symbols]

 M Master S1 to Sn Slave L1 Data communication line L2 Alarm communication line 15 Communication control circuit 28 Servo motor 40 Belt conveyor 41 Container 42 Injector

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazumasa Shimura 3580 Kobaba, Oshino-son, Oshino-mura, Minamitsuru-gun, Yamanashi F-Fac Co., Ltd. F-term (reference) 5H269 AB01 BB05 CC02 CC13 DD01 EE01 EE05 EE10 EE11 FF06 GG02 JJ02 KK05 MM05 NN02 QB06 QD02 QD03

Claims (8)

[Claims] 1. One of a plurality of control devices is a master unit and another control device is a slave unit. The slave unit stores data relating to its own axis position with respect to reference data, and establishes a connection between the master unit and the slave unit. Multi-axis coordination that connects by a communication path and transmits reference data from the master unit to each slave unit, and each slave unit controls the position by driving the control axis based on the data of the position corresponding to the received reference data In the control method, the communication path is composed of two communication lines, and the master unit transmits the reference data simultaneously via one of the communication lines, and the slave unit transmits the data at a timing determined to receive the reference data. Send the reception completion signal to the master unit via the other communication line, and Is a multi-axis cooperative control method, characterized in that a received slave unit is determined based on a time-series position of each data reception completion signal transmitted via the other communication line. Each slave unit outputs an alarm to the other communication line when an abnormality occurs in each slave unit, and the master unit checks the data reception completion signal in the first half of its own basic cycle. 2. The multi-axis cooperative control method according to claim 1, wherein the alarm output is detected in the latter half. 3. A configuration mode and a data communication mode. If an alarm is output from any of the units while data is being transmitted / received in the data communication mode, the mode shifts to the configuration mode, and the master unit is switched. And the slave unit perform one-to-one communication,
3. The multi-axis cooperative control method according to claim 2, wherein at least status information of the unit in which the alarm has occurred is displayed on a display device of the master unit. 4. A method according to claim 1, wherein one of the plurality of control devices is a master unit and the other control device is a slave unit. The slave unit includes a table for storing data relating to its own axis position with respect to reference data. The units are connected by a communication path to transmit reference data from the master unit to each slave unit, and each slave obtains data of a position corresponding to the received reference data from the table, and controls the control axis based on the data of the position. In the multi-axis cooperative control method of controlling the position by driving the master unit, the master unit and each slave unit have respective basic periods having a common cycle width, and the master unit transmits the reference data based on its own basic period. The slave unit transmits the signal based on the phase difference between the basic period of the master unit and its own basic period. A multi-axis system that corrects the received reference data, obtains data on the position of the control axis of the slave unit from the table based on the corrected reference data, and drives the control axis based on the data to control the position. Cooperative control method. 5. The master unit and each slave unit have respective basic periods having a common period width, the master unit transmits the reference data based on its own basic period, and the slave unit transmits the basic period of the master unit. And the reference data received by the phase difference of its own basic cycle is corrected, data on the position of the control axis of the slave unit is obtained from the table based on the corrected reference data, and the control axis is determined based on the data. 4. The multi-axis coordinated control method according to claim 1, wherein the position is controlled by driving. 6. The slave unit measures the time from the start of the reference cycle of the slave unit to the completion of the reception of the reference data, and based on the measurement result, determines the basic cycle of the master unit and the basic cycle of each slave unit. The multi-axis cooperative control method according to claim 4 or 5, wherein the phase difference is calculated. 7. When the slave unit does not receive the reference data within its own basic cycle, the slave unit estimates the reference data and the phase difference in the basic cycle based on the previously received reference data and the obtained phase difference. 7. The value as reference data and a phase difference in the basic cycle.
The described multi-axis cooperative control method. 8. A code of a slave unit cooperating with the master unit is set, the master unit transmits the set code together with the reference data, and the slave unit receives the reference code only when its own code is transmitted. The multi-axis cooperative control method according to any one of claims 1 to 7, wherein cooperative operation is performed.