JPS6161675A - Control system for varnish device - Google Patents

Abstract

PURPOSE:To make possible the simultaneous and automatic control of manipulated variable such as the heating temp. of a heater in such a manner that the respective controlled variables attain respectively desired values in the stage executing the multi-variable control of a varnish device. CONSTITUTION:The initial value of integral control action is first set at the measured quantities Y1-Y3 including the controlled variables Y1, Y2 by operat ing the varnish device 1. Then a CPU reads the data of the measuring quantities Y1-Y3 including the target values YR1-YR2 and controlled variables Y1, Y2. The computing element C, feedback element F and feed forward element N of the CPU make computation in accordance with said data in such a manner that the respective manipulated variable outputs U'c, UF, UN attain prescribed rangevalue. The manipulated variables U'c1, U'c2 are subjected to integral control action until the differences epsilon1, epsilon2 between the target values and the controlled variables are made zero. The manipulated variable U=Uc-UF+UN is calcu lated in such a manner that the controlled variables are approximated as far as possible to the target values and the result thereof is outputted to a con trolled system 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for a varnishing device, and particularly to a control method for a varnishing device in which a controlled variable such as the temperature inside the device is multivariable.

BACKGROUND ART A hot air circulation type enamelled wire baking furnace for producing insulated wires used in electric motors and the like by baking insulating paint on copper wires, aluminum wires, etc. has been known. This baking furnace uses a baking varnish (for example, ester-based or formalin-based resin) that is applied in advance to the electric wires that are fed to the furnace.
1w of solvent.

This is a furnace that burns and bakes using high-temperature gas that is circulated and supplied through several dampers. The process of applying varnish using a varnishing device attached to this furnace and baking it again using a baking furnace was repeated several times to obtain an enameled wire with a uniform finished outer diameter. In this process, in order to make the finished outer diameter of the enameled wire uniform, the temperature of the varnish during application in the varnishing device must be constantly controlled to be constant. One conventional method for controlling the varnish temperature in a varnishing device is to perform PID control on the heater of a heating device installed in the varnishing device, or to provide a varnish tank on the varnishing device side, and to control the varnish temperature in the varnishing device. The temperature of the heat medium that heats the varnish inside is measured using a temperature controller, and the heater for the heat medium is controlled by PID. That is, as shown in Figure 1,
The varnishing device 1 includes a varnishing device 3 that applies varnish 2 onto electric wires fed from an enameled wire baking furnace, and this device 3.
The varnish 5 in the tank 4 communicating with the tank 4 is circulated.

and a vibro and pump 7 for replenishing the device 3.

In order to maintain the varnish 5 in the tank 4 at a predetermined temperature, the heating furnace 10 includes a heater 9a that heats a heat medium (water or oil) 8 surrounding the tank 4.

Then, the varnish is applied to the coating device 3 and the tank 4 by keeping the temperature 1 of the varnish 2 constant and adjusting the varnish viscosity, concentration, etc.
The varnish 2 is applied to the wire by circulating it between the wires in the direction of the arrow. The temperature of the varnish is controlled by controlling the temperature T1 of the varnish 2 in the coating device 3 using a thermocouple 11, controlling the temperature R2 of the varnish 4 in the tank 4 using a thermocouple 12, and controlling the temperature T1 of the varnish 2 in the coating device 3 using a thermocouple 12.
3 is detected by the thermocouple 13, and the heater 9a that heats the heat medium 8 is PID-controlled as described below so that the 1L degree TI is always constant. That is, the varnish temperature of the coating device 3 set in advance is Sl, and the temperature T
Due to the difference ε1 between I and temperature S1, the set temperature of the varnish 5 in the tank 4 is set to S in the construction operation, and the set temperature of the heat medium 8 is set to 89 in the PI operation due to the difference between the temperature T2 and the temperature S7 is set to 2. , temperature T3 and temperature S3, ε3, I10 controller 14 changes the operation amount of heater 9 by PID operation to A/
D-convert. The signal is then supplied to the CI'tl 15 and subjected to arithmetic control. The signal is again input to the heater 9 as shown by the dotted line via the I10 controller 14, and is controlled so that the temperature T1 is always constant.

By the way, when using the above-mentioned varnish heating means,
In the former case, variations in temperature distribution occur between the periphery of the heating part and the area other than the periphery of the heating part, and the varnish cannot be applied properly, resulting in uneven finished outer diameter of the enameled wire. In the latter case, the heater 9 of the heat medium 8 is controlled based on the temperature T2 of the varnish 5 in the tank 4, but there is a delay due to differences in heat conduction time, etc., and the temperature T8 rises abnormally. It becomes difficult to set T1 accurately. Furthermore, since the temperature T3 is not directly controlled, the relationship between the temperatures T3 and T2 is determined empirically according to external conditions (for example, summer, winter seasons, etc.).

If temperature T8 is not set, the temperature T of varnish 2.

cannot be kept constant. As a result, the finished outer diameter of the enameled wire becomes uneven. Further, the wire diameter of the applied T-line ranges from about 0.2 to 2 mmφ. Therefore, the speed of the wire fed to the varnishing device 1 varies depending on the wire diameter and also varies depending on the type of varnish. In other words, under these circumstances, the PID control method can accurately control temperature T3, but cannot control temperature T2゜temperature T1, and temperature 'r, temperature -[+, may vary depending on external conditions, etc. 6. In particular, when trying to control only the temperature 1'1 in the coating device 3, the 1 time constant becomes extremely large. .

Controllability deteriorates significantly.

This is because the temperature at one of the measurement points is controlled to a desired value, so if the heater 9 is adjusted, for example, even if the temperature at that point can be adjusted to the desired value, the temperature at all other points will also change. This is because you end up doing it.

In other words, four control variables (in the case of this embodiment, tank 4
．． A plurality of measured quantities (in the case of this example, the temperature in the tank 4.heating furnace 10° coating device 3) including the temperature in the heating furnace 10) is a plurality of manipulated variables (the heating temperature of the heaters 9a-c).
In control (multivariable control) where each variable changes when one of them is operated, each manipulated variable is simultaneously and automatically adjusted so that each controlled variable becomes the desired value by measuring the measured amount. control was not possible with the prior art.

Furthermore, due to the correlation between the controlled variable and the manipulated variable of multiple variables, a control method that relies on each pair of controlled variable and manipulated variable has the disadvantage that the stability of the controlled variable is poor and the responsiveness is poor. Ta. Therefore, the main purpose of the present invention is to perform multivariable control of a varnish system by detecting elements for measuring variables including controlled variables such as temperature in each device, so that each controlled variable can be set to a desired value (set target value). It is an object of the present invention to provide a control method (system) for a varnish device that simultaneously and automatically controls manipulated variables such as the heating temperature of a heater so that the heating temperature of the heater reaches the desired value.

Another object of the invention is to provide control means with improved stability and/or responsiveness in such a system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the varnish apparatus control method according to the present invention is applied to temperature control of a varnish application apparatus will be described in detail below with reference to the drawings.

First, in this embodiment, as shown in FIG.
0. The coating device 3 is provided with heaters 9a and 9b. and coating device 3. The tank 4° heating furnace 10 is equipped with thermocouples 11, 12, and 13, and the pump 7 is equipped with a flow meter 146, and each thermocouple outputs an output signal (
(indicated by a solid line) is generated, and the CPU 16 (HP 1 manufactured by Hewlett Paracard Co., Ltd.) is generated via the 110 controller 15.
000M series), and the calculated and controlled signals are again supplied to the heater 9 via the controller 15.
a, b (indicated by dotted lines).

Next, such a control system will be explained in detail in FIG.

In this method, a plurality of measured quantities (applying device 3, tank 4, heating furnace I
It is intended to control the manipulated variable so that the temperature at O is adjusted in multiple ways, such as the temperature of the heat medium by the heaters 9a and b.

The control amounts y, , y, are connected to the subtraction point 22 of the target values YR, , YR, drawn from the drawing point 21, respectively,
The difference between the controlled variable and the target value is obtained.

These differences! ε2 is applied to the calculation element C. Catechism C is a matrix written as.

These manipulated variables are the integrators t,
, 12 and an integral operation is performed to obtain the quantity Uc1.
It is applied to each manipulated variable IJ +' and U 2 as LJc2.

This quantity Uc is expressed as follows as a result of performing an integral function.

This integral operation includes not only a linear integral function by an integrator but also an operation that includes or is similar to an integral function.

Further, the integral operation may include dynamic compensation.

In addition, before automatically controlling the varnish apparatus 1 as a control object, each element of the calculation element C is calculated based on the optimal control theory using the control object as a model, and when giving the target value Yl (1 to YR2). Manipulated variable U' c l = U' C7, manipulated variable U1 to U2
．． This is determined most appropriately by simulating the behavior of the control amounts Y1 and Y2.

Further, the extraction point 21 is connected to the subtraction point 23 via a feedback element T'. As a result, a feedback operation is performed by linear processing on the measured quantities Y1 to Y,1 including the controlled quantities y, , y, and the manipulated quantities LJ, , U2 are applied in a subtractive manner. The feedback output LIF may include dynamic compensation in this feed pack operation.

Each element is also determined in advance by the aforementioned optimal control theory and simulation.

Furthermore, the extraction point 24 is connected via a feedforward element N to the summing point 23. As a result, a feedforward operation, that is, a proportional operation to the target (direct YH, ,YR, , is performed by linear processing and is additively applied to the manipulated variable U, ,U. The feedforward output LIN may include compensation.

It is.

Each element is also determined in advance using the optimal control theory and the simulation method, as described above.

In this way, as a result of three types of operation inputs being supplied to the manipulated variable U, the manipulated variable U finally becomes as follows.

U=UC-UF+UN A limiter Li=L2 is interposed in each operating line to stop the integral operation when the sum output UC-UF+UN supplied to the manipulated variable exceeds a predetermined range ( Figure 2).

In Fig. 2, the part enclosed by a dotted line represents the CPU, and the input interface for target values YR and #YR2 is an A/D
Input/output device for conversion l10-1゜operated amount U, ,U
The output interface of No. 2 includes an input/output device l10-2 for D/A conversion, and a measured quantity Y1 including control quantities Y1 to Y2.
~The input interface to the backward path of Y8 is A/
The multivariable automatic control system thus constructed, in which the input/output device 110-3 for D conversion is interposed (FIG. 2), operates as follows.

First, the varnishing device 1 is operated to set the initial value of the integral operation according to the measured quantities Y1 to Y3 including the controlled quantities Y1 to Y2 (Fig. 3).8Then, the CPU sets the target values YR to YR2.
, the data of the measured quantities Y, -Y3 including the controlled quantities Y□ -Y2 are read. CPU calculation element C, feedback element F
, feedforward element N performs its operation according to the value expressed by the above-mentioned determinant, respectively, and calculates .

This manipulated variable output needs to be controlled and maintained within a predetermined range. Therefore, it is determined whether each manipulated variable output value is within the range, and if it is within the range, an integral operation is performed, and if it exceeds the range, it is output via limiter L. (Figure 3).

In this way, each manipulated variable U'c1, U'c
2 are integrators 11. I2 is activated and an integral operation is performed to produce an integral output.

If such a function is introduced, even if the heating temperature of the heaters 9a and b as the manipulated variable is within a predetermined range as in this embodiment, if the integral operation is performed from the start of the operation, Since the differences t1 and ε2 between the manipulated variable and the target value are initially large, generation of an inconvenient manipulated variable signal that would abnormally increase the heating temperature can be avoided.

In this way, the integrator repeats the integration operation until the difference between the target value and the controlled variable becomes zero, forming a control loop so that the controlled variable approaches the target value as much as possible.

Therefore, the manipulated variable U U = Uc - UF + UN is calculated and output to the controlled object 1.

In this case, the feedback output UF of the feedback element F has the function of stabilizing the inherent characteristics of the control system.

On the other hand, the output UN of the feedforward element N is.

This is to accelerate the rise of the control amount Y so that it quickly approaches the target value YR, and has a great effect particularly at the start of operation of the device. This element N further improves the responsiveness of the control system.

In this way, when the manipulated variable U is output to the controlled object 1, the next sampling is delayed for a predetermined time and the next operation is repeated again.

In the above embodiment, the varnish is applied from the varnish tank 4 by the application device! By providing a heater 9c in the vibro that supplies the air to the vibro 3, and controlling this using the third operation amount U,
A more accurate control system can be configured.

In the above embodiment, the case was explained in which there were two controlled variables and target values, two manipulated variables and manipulated variables, and three measured quantities. is an integer of
The present invention is equally applicable to the case where m≧Q).

As is clear from the above examples, according to the present invention,
When a measured quantity including multiple controlled variables, such as temperature, of a varnishing device as a controlled object fluctuates depending on any of multiple manipulated variables, such as the heating temperature by a heater, it is possible to set the controlled variable to its target value. In controlling the amount of operation to be adjusted.

Since the integral operation is performed on each manipulated variable obtained from the difference between the controlled variable and the target value and applied to each manipulated variable, each manipulated variable performs its function mutually and independently, and the controlled variable is Multivariable control is performed to approach the target value.

In addition, this control system includes feedforward operation and (
or) by performing a feedback action.
Improved response and increased stability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a varnish device as a controlled object. FIG. 2 is a block diagram of an automatic control system in which the present invention is applied to the controlled object, and FIG. 3 is an operational flowchart of the system. Yl, Y2... Controlled amount Y1-Y3... Measured amount

Claims (11)

[Claims] (1) For example, the varnish temperature in the varnish tank and the varnish temperature in the coating device of a varnish device that has a varnish tank, a heat medium heating furnace surrounding the tank, and a coating device to which varnish is supplied from the varnish tank via a pipe. A plurality of measured quantities [Y_1] include a plurality of controlled quantities Y=[Y_1...Y_2], such as the varnish temperature in the varnish tank, the varnish temperature in the coating device, and the heat medium temperature in the heat medium heating furnace. ...... Y_m] is a plurality of operation variables U = [U_l
...U_n] (where l, n, and m are positive integers of 2 or more, and m≧l), the control amount changes to its target value YR=[YR_1...・・・YR_l] In controlling the manipulated variable so that it is adjusted to, the manipulated variable U'c = [U A control system for a varnishing device characterized in that the output Uc=[Uc_1...Uc_n] obtained by performing an integral operation on each of 'c_1...U'c_n] is used as each manipulated variable. (2) Applying the output UF_1=[UF_1...UF_n] obtained by performing a feedback operation to the plurality of measured quantities [Y_1...Y_m] including the controlled quantity to the manipulated variable; A control system for a varnish device according to claim 1, characterized in that: (3) According to claim 1 or 2, the output UN=[UN_1...UN_n] obtained by performing a feedforward operation on the target value is applied to the manipulated variable. Control method of varnish equipment. (4) The integral operation is stopped when the sum output of the output Uc - the output UF + the output UN supplied to the manipulated variable exceeds a predetermined range. Control method of the varnishing device described in Section. (5) Claim 1 or 2, characterized in that the initial value of the integral operation is set according to the measured quantity.
Control method of the varnishing device described in Section. (6) A control method for a varnishing apparatus according to claim 1, wherein the manipulated variable and the integral operation are obtained by linear processing. (7) A control method for a varnish device according to claim 1, wherein the manipulated variable includes dynamic compensation. (8) A control method for a varnish device according to claim 2, wherein the feedback operation is obtained by linear processing. (9) A control method for a varnish device according to claim 2, wherein the feedback operation includes dynamic compensation. (10) A control method for a varnishing device according to claim 3, wherein the feedforward operation is obtained by linear processing. (11) A control method for a varnish device according to claim 3, wherein the feedforward operation includes dynamic compensation.