JPS61235907A - Controlling method for programmable controller - Google Patents

Abstract

PURPOSE:To execute a sequence control containing a control of a continuous quantity by changing an operational condition and annihilating a token, when a block for changing the operational condition is started, and generating the token in a block to be started, when a set condition is formed. CONSTITUTION:A token is annihilated by a control input for changing an operational condition, and from a control output, the token is generated. That is to say, when the token is inputted, the control input changes a data of its box, and the token which has been inputted from the control input is annihilated. That is to say, the control input becomes a sink box for erasing the token. On the other hand, when a set condition is formed in the course of executing an operation of the box, a token is generated from the control output, the box following it is started, and the control output becomes a source box for generating the token.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method of controlling a programmable controller, and particularly to a method of controlling a programmable controller that also controls continuous quantities such as analog quantities. [Background of the Invention] Recently, methods have been studied to express programmable controller inputs more easily and systematically. This is one method based on Petri nets,
For example, Proceedings of the Society of Instrument and Control Engineers, September 1984 issue 84
It is described on page 4 [Highly flexible FA control system based on Petri net]. According to this, the operations and logic of sequence control can be expressed in an easy-to-understand manner, and control can be executed at high speed.

However, if a controller using this expression method is used to control a continuous system such as a servo motor, the following problem will occur. In other words, since the representation method using Petri nets is only concerned with sequence control,
For continuous systems, they could only give instructions to start the operation, and could not be involved in the control contents themselves, whose values change moment by moment.

Therefore, there is a problem that this expression method cannot be applied to continuous system control.

[Purpose of the invention]

The present invention has been made to solve the above problems.

The purpose is to provide a control method for a programmable controller that can easily perform sequence control including continuous control such as analog control.

[Summary of the invention]

The feature of the present invention is that a block for changing the calculation conditions is activated for the control calculation of the continuous system in operation, in order to change the calculation conditions or perform other control according to the operation status. Then, in order to change the calculation conditions and make the token disappear, and to control other devices according to the operating status, when the set conditions are met, a token is generated in the block that should be activated by it. be.

(Embodiment of the Invention) FIG. 2 shows an example of a representation method of a programmable controller to which the present invention is applied. In FIG. 2, Bn (n is an integer) is a box representing a state and a unit of operation.

When a token (indicated by a black circle) as shown in B3 in the figure is entered into this box, the operation of that box is activated.

The token moves from box to box following the arrows between the boxes, and the box in which the token resides is activated. 0
n (n is an integer) represents a gate for controlling movement of tokens between boxes.

In FIG. 1, the output of box B1 passes through gate Gl and is input to control input C1 of box B4. Control output C2 of box B4 is input to box B2 through gate G2.

Furthermore, the output of box B3 passes through gate G3 and is input into box B4, and the output of box B4 passes through gate G4 and is input into box B5.

The tokens present in the box can pass through the gate if the first-order condition is satisfied, except when the input/output of the gate is a control input Cn (n is an integer), which will be described later.

(1) There are tokens in all boxes on the input side,
Furthermore, the operation content (computation content) specified by the box has been completed.

(2) There are no tokens in any boxes on the output side.

When a token passes through the gate, all tokens in the boxes on the input side of the gate disappear, and tokens are generated in all boxes on the output side of the gate.

In the example shown in Figure 2, the token exists only in B3, so when the operation of B3 is completed, the token moves to 84, and
4 is activated. When the operation of B4 is completed, the token of B4 is moved to B5.

Then, the operation of B5 is activated. In this way, the operation of each box is implemented.

The specific calculations performed by each box are executed according to the contents described by commands as shown in FIG. FIG. 3 is an example of this, with boxes Bl, B2. B3. B
As can be seen from Figure 2, the calculations in box B4 involve logic and numerical processing, and the calculations in box B4 deal with continuous systems, that is, servo motors.

B4 has a control input C1 and a control output C2, and it is possible to change and output data of B4. C1 and 02 work as follows.

That is, when a token enters B1, the operation 81 is executed, and the data 84 is changed based on the result. At this time, in the example of FIG. 2, the input gate G1 of the control input C1 is not connected to any box other than B1, so
Immediately after the calculation of B1 is completed, the data in 84 is changed through C1, but if other boxes exist, the data in B4 is changed when the above passing conditions (1) and (2) are satisfied. On the other hand, when the condition set there during the calculation of B4 is satisfied, a token is output from the control output C2, and if G2 can be passed, the token is input to B2, and the operation of B2 is executed.

Each box performs the following operation when a token enters it. In the case of FIG. 3, B1 changes the constant K to 5. B2 turns on the output of control output number 61. B3 waits until the input with input number 51 turns on, and when it turns on, sets the constant K to 2.

B4 is a calculation for positioning the servo, and is the servo axis number 1.
Perform one positioning with the target position of 500XK, B3
A token enters B4 from , and the target position is set to 500x2=1
If a token enters B1 while positioning is being performed as 000, the target position is set to 500x through control human power C1.
5=2500 and execute positioning. Note that in the one shown in the figure, only the final target position is given, but positioning may also be performed while specifying the speed.
Furthermore, in B4, the following calculation is performed. Current position P is 500
When the above is reached, C2 is turned on, that is, a token is put into C2. B5 turns off the output of output number 62.

FIG. 1 shows the configuration of a control device that executes the programs shown in FIGS. 2 and 3. Controller 1 receives a signal from switch 2 and controls relays 3 and 4 and servo motor 5. Here, switches, relays, and servo motors are connected in accordance with FIGS. 1 and 2, but it goes without saying that there are other switches, relays, etc. in the entire system.

The controller 1 is configured as follows. processor 1
01 is activated according to the procedure shown in the system memory 102, and calculations are executed according to the contents of the program memory 103. Data necessary for calculation is stored in data memory 10.
4 and output to the processor 101 as necessary. Processor 101, system memory 102, program memory 103. Data memory 104 is connected to latch circuits 106, 108, 110 and interface 105 by bus 114, and signals are exchanged. The output of switch 2 is connected to input circuit 1 through input contact 51.
07 is input. The output of the input circuit 107 is connected to the latch circuit 106, and the signal is transmitted to the processor 101 through the latch circuit 106. Signals for turning on and off relays 3 and 4 from processor 101 are latched by latch circuits 108, and their outputs are sent to output circuits 109.
The output of the output circuit 109 is connected to the relay 3 through the output contact 61 and to the relay 4 through the output contact 62, respectively. On the other hand, the target position of the servo motor 5 is latched by a latch circuit 110, and its output is transmitted to a position control circuit 111. It counts the current position, calculates the deviation from the target position, and outputs a speed command signal accordingly. A speed command signal from position control circuit 111 is input to speed control circuit 112 . The speed control circuit 112 detects the rotational speed of the servo motor 5 from the output signal of the pulse encoder 6, calculates the deviation from the speed command signal, and outputs a torque command signal accordingly. A torque command signal from speed control circuit 112 is input to power circuit 113. The power circuit 113 supplies current to the servo motor 5 according to the torque command signal.

The apparatus shown in FIG. 1 operates as follows. Figures 2 and 3
The program shown in the figure is a personal computer (hereinafter referred to as
It is input from 7 (abbreviated as PC). The personal computer 7 converts the input program into a form that can be executed by the controller 1 and sends it to the interface 105. This signal is stored in program memory 103. When the processor 101 is activated by the system memo IJ 102, programs as shown in FIGS. 2 and 3 are executed according to the program memory 103. When box B3 is activated,
The on/off state of the switch 2 is read by the processor 101 through the input circuit 107 and the latch circuit 106.

B2. When B5 is activated, on and off signals are transmitted to relays 3 and 4 through latch circuit 108 and output circuit 109, respectively. When B4 is activated, the position target signal passes through the latch circuit 110 to the position control circuit 111.
can be conveyed to. The current position of the servo motor 5 is transmitted from the position detection circuit 111 to the processor 10 through the latch circuit 110.
1 to determine the status of the current position and whether positioning has been completed. The control device of FIG. 1 operates in this manner.

When the system shown in Fig. 1 is programmed using the representation method shown in Figs. 2 and 3, the control flow is summarized as shown in Figs. 4 and 5. As shown in Fig. 0, the control inputs are When entered, it changes the data in that box and destroys the token entered from the control input.

That is, the control input is 5ink which erases the token.
It becomes a box. On the other hand, if a set condition is met during the execution of a box operation, a token is issued from the control output and the following box is activated.

That is, the control output is 5 which generates a token.
It becomes the source box. The feature is that the control input and output of the token have the above functions.

The flow shown in FIG. 4 will be explained. First of all, extract one of the boxes where the token exists (1)0 Next,
Calculate the processing contents of the box (2) 6 The calculation contents of each box are specified as shown in FIG. Then, as a result of the calculation, it is determined whether the specified logic is established, for example, whether the servo positioning has been completed (3),
If the logic holds true, then it is determined whether the token can be transferred, that is, whether the gate passing conditions shown earlier are satisfied (4). If the logic is not held, the transfer is not possible. If so, re-register the box (5) and perform the calculation again. If token transfer is possible, determine whether the destination is a control input (6)
. In the case of control input, of course, change the constants in the box (7) and return to the beginning. At this time, the token disappears. If it is not a control input, the output side box of that gate is newly registered (8) so that the calculation of that box can be executed in the first place. Note that here we have shown the flow when there is one box or one control input on the output side of the gate, but if there are multiple, it goes without saying that steps (6) to (8) must be repeated for each. none).

FIG. 5 shows a flow when there is a gate output such as box B4 in FIGS. 2 and 3. This flow corresponds to steps (2) and (3) in FIG. 4. First, perform the calculation. In terms of B4, this corresponds to a calculation that outputs a position command. Then, it is determined whether C0DE is 1 or not. Here C
0DE is to prevent the token from being issued again when the calculation in this box is executed after the judgment condition is met and the token is issued from the control output.
C0DE=1 indicates that the token has been issued.

Of course, if you want to make ground movements, such as when tokens are issued continuously from the control output, you will need to change C0DE in various ways. The flow is, if C0DE=O, then check whether 1 judgment condition is satisfied (13),
As a judgment condition, in B4, if the 0 condition, which is whether the current position P has become 500 or more, is satisfied, a token is output from the control output, and it is checked whether the gate connected to it can be passed through. C if migration is possible
0DE is set to 1 (15), and the box on the output side of the gate is registered in order to execute the step (1) in FIG. 4 (16).

Thus, a token is emitted from the control output and 1
The next step (17) is executed. When C0DE is 1, when the condition is not satisfied, or when the transition is impossible, the process jumps to step (17) as shown in the figure. In step (17), it is determined whether the logic is satisfied.

In the example of B4, it is determined whether positioning is completed.

If it holds true, step (4) in FIG. 4 is executed, and if it does not hold, step (5) is executed.

By doing as described above, it is possible to change the calculation conditions for the box that controls the continuous amount, and it is also possible to output a signal to the outside that corresponds to the status of the box during activation. In addition, tokens disappear when a control input is used to change calculation conditions, and a token is generated from a control output that outputs a signal according to the situation inside the box, so the operation of the box connected to the control input or output is controlled. Can be done normally.

In the above embodiment, one box has both control input and output, but it may have only either control input or output.

The control input C1 and output C2 shown in FIG. 2 are an example of the expression method, and it goes without saying that other expression methods may be used. FIG. 6 shows an example. Boxes B4' and B4' surrounded by double frames correspond to C1 and C2 in FIG. 1, respectively. 5ink box B4' instead of C1,
A 5source box B4' may be placed in place of C2. When a token enters B4', the calculation condition of B4 is changed. Further, when the condition specified in the calculation of B4 is satisfied, a token is issued to B4'. In any case, in order to change the calculation condition, use 5 ink for the box where the token to execute it exists, and the result is activated so that the calculation condition in the box can be output to the outside. 5o so that tokens appear in the box
In addition, since only B1 is input to the input gate G1 of 84', B4'
1 operation may be performed. Similarly, since only B2 is connected to the output gate G2 of 84'', the calculation of B2 may be performed by B4'.

In the above embodiment, the box that issues a position command for the servo motor is provided with a control input and an output, but it can be applied to a box that performs other calculations. FIG. 7 shows an example of this. Box B13 simply executes an operation to turn on output number 71, but when a token is entered in Bll and the value of the constant is changed, the operation of B13 changes. That is, after B13 is activated, if a token enters Bll and the value of K is changed while the token remains in B13 until input number 81 is turned on in B14, output number 71 is turned off. be done.

This allows you to change control of B13 while it is running, and also allows you to change control of B11 when B13 has no tokens.
Even if a token enters, the operation can proceed without affecting others.

In this way, the present invention can also be applied to devices that perform interrotter operations.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to change the constants and extract the state of control calculations that are continuously operating. As a result, the controller having the expression method shown in the present invention can be applied to various motion control devices that perform positioning and logical processing.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention, Fig. 2, Fig. 3
FIG. 4 is an example of the method of expressing the present invention. FIG. 5 is a control flowchart according to the present invention, FIG. 6 is an example of another representation method, and FIG. 7 is an example in which the representation methods of FIGS. 1 and 3 are applied to other control calculations. B1 to B5...Box, Gl, G2...Gate,
1 wound! Cause! X2 Figure 13 Figure Bl: ni-5 82 2-cho 61-σ8 δ3; 1. kt''# X1t-an, then 2a+: st-#7nehatt/a-7t P-fE, jθσ, t/l
ea l:2-0/IB5: γΔ2-σff Figure 14 Figure 5 (Go to Rikau (4) Go to (5)・σha bf 1m (. T7/Lightning σff M KJ/.

Claims (1)

[Claims] 1. It has a box that divides the operation of the control system to be controlled into operation units, a token that activates each box, and a gate that controls the operation of the token, and by moving the tokens of the box one after another. In a programmable controller configured to advance control operations, when a token is input to a second box for changing the operating state of a first box that continuously performs operations, the first A method for controlling a programmable controller, characterized in that the token in the second box disappears after changing the operating state of the box.