JPS60171502A - Controller of multi-variable control system - Google Patents

Abstract

PURPOSE:To decrease the number of parameters to be controlled and also to reduce the time and labor for control by constituting a controller with a PID controller and a multiplier set in response to the main and secondary group systems respectively. CONSTITUTION:For a controller 9, the operation quantity 10 delivered from an adder 21 is equal to the value obtained by adding the operation quantity 17 given from a PID controller 13 and the value 102 obtained by multiplying the control quantity 20 given from another PID controller 14 by a certain constant alpha through a multiplier 100. While the operation quantity 11 delivered from another adder 22 is equal to the value obtained by adding the quantity 20 and the value 103 obtained by multiplying the quantity 17 by a certain constant beta through a multiplier 101. In such a constitution, the number of PID controllers can be decreased by using a multiplier to obtain the effect equivalent to the PID controller. This decreases the number of parameters to be controlled and then reduces the time and labor for control.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device in a multivariable control system (multi-input, multi-output control system) in which the controlled object is an interference system.

In general, a control device in a multivariable control system receives multiple outputs from a controlled object, performs predetermined calculations based on these, and provides the obtained manipulated variables to the controlled object as multiple inputs.

Here, in order to facilitate understanding, a case of a two-man power, two-output control system will be taken as an example and explained with reference to FIG. In FIG. 1, 1 is one output signal 2 of the controlled object 12 (this is y
, where 3 is 8+
-yt is a subtracter, and 4 is its output, ie, S.

represents the deviation signal e between and y. Similarly, 5 indicates a set value signal S2 for the other output signal 6 (this is designated as y2) of the controlled object 12, 7 indicates a subtracter that performs the calculation of 5t-yt, and 8 indicates its output, that is, S. represents a deviation signal e2 from y. Reference numeral 9 denotes a controller to which the deviation signal e-1ee2 is input, and this controller 9 performs a predetermined calculation based on else and outputs the output signals 1o and I to the controlled object 12.
I, that is, provides the manipulated variables ul and u2 to the controlled object 12. FIG. 2 shows an example of the configuration of such a controller 9. In Figure 2, 13 is one person, P I corresponding to the yarn
The Dl1 regulator Cll, 14 is the other person, the PID regulator C4 corresponding to the output system.

In the control system shown in FIG. 1, if the controller 9 is configured as shown in FIG. 2, its function will be as follows. In other words, the PID adjustment C,,)xs is the controlled object 1
The manipulated variable (ul) 10 is calculated according to the magnitude of the deviation signal (e+ = 8t -'/r) 4 so that the output signal y of 2 becomes the set value signal S, and is output. Similarly, P
The ID controller (cwt) z4 outputs the output signal y of the controlled object 12.
! In order to make the set value signal S, the deviation signal (e = 8
The manipulated variable (ul) 17 is calculated and output according to the magnitude of 2'It)II.

In this way, PID p1 node CC node *Ca)1B,
If the three parameters of -'/z can be controlled to be equal to the desired setpoint signal SI eS2.

The above explanation is that the controlled object 12 is a non-interfering system, that is, the output y1 of the controlled object 12 can only affect the manipulated variable U.
Also, the output y2 is the production amount U.

However, the controlled object 12 is an interference system, that is, the output y of the controlled object 12 is affected by both the manipulated variables U and u2, and the output y2 is also affected by U. , and ut = In the case where both are affected, the configuration of the controller 9 must be as shown in FIG. In Figure 3, the PID regulator (C
o) fJ and (CI, 1) 15 are operated according to the magnitude of the deviation signal (e,)4 1t(ulj)J7*(u+,)z
9 and also calculate the PID regulators (C2,)16 and (C
n) Z4 calculates the manipulated variable (uz+)z8゜(un)J(' according to the magnitude of the deviation signal (ex) Ji and outputs 0. Furthermore, the manipulated variable (uIl) 27 and (uJJ& are adders) 21, and the final operation amount (u, = u□
+utt>i.

becomes. Similarly, the manipulated variables (u,,) J 9 and (u22)
20 is added by the adder 22, and the final operation amount (u
, =ufeng+u, , )xl.

In this way, when the controlled object 12 is an interference system, by providing the PID adjusters (C, 2, C, , ) J 5 , 16, the influence of one deviation signal e+ (eg) can be reduced to the other manipulated variable u2. (ul) can be reflected in the respective output signals y, as a total.

y2 can be controlled to be equal to the respective set value signals S, , S,.

However, in the controller 9 configured as shown in FIG.
A total of four regulators are required for the main loop system and the sub loop system, and the number of parameters that must be adjusted depends on each PI.
Since the D adjuster has 3 parameters, a total of 12 (4X3
) is 0. Here, the main loop system is 4 in Figure 3.
→13→17→21→10 and 8→14→20→22→1
1, which is a system that directly affects the output of the controlled object, and the sub-loop system is the path 4→15→19→22→11 and 8→16→18→ in Fig. 3. 21
→It is a system that has 10 routes and indirectly affects the controlled object. Therefore, the controlled object 12 has m input 1
In the general case of m output, it is necessary to adjust the parameters by the number of 3・R, and the larger the number of m, the more parameters need to be adjusted. It also takes a lot of effort to adjust the values.

The present invention has been made in view of the above circumstances, and is a controller installed in a multivariable control system where the controlled object is an interference system, by reducing the number of PID controllers without changing its performance. It is an object of the present invention to provide a control device for a multivariable control system that can reduce the number of parameters to be adjusted as much as possible and also reduce the amount of effort required for adjusting parameter values.

In order to achieve such an object, the present invention is a controller installed in a multivariable control system with m inputs and m outputs.
It is characterized by using a regulator and using a multiplier for the sub-loop system that indirectly affects the system.

An embodiment of the present invention will be described below with reference to FIG.

FIG. 4 shows the configuration of the controller 9 having the same performance as that in FIG. 3, and the same parts as in FIG. 3 are given the same reference numerals and will be explained. In FIG. 4, 4 is the controlled object 1 shown in FIG.
One output signal 2 (y+) of 2 and its set value signal 1 (
The deviation signal e1.8 with respect to Sl) is the same as the other output signal 6 (y2) of the controlled object 12 and its set value signal 5 (S2).
This is the deviation signal e2 from Further, 13 is a PID controller CI+ to which el is input, and 014 is a PID controller 22 to which e2 is input, which outputs the manipulated variable 17 (uI+).
Then, the operating device -,2o (I22) is output. 1 more
oθ is a multiplier to which the manipulated variable 2f7 (I22) is input;
The manipulated variable 102 (u2
□′) is output. Reference numeral 101 denotes a multiplier to which the manipulated variable 17 (up) is input, and the manipulated variable 103 (un') obtained by multiplying the manipulated variable u11 by a certain constant β is inputted. 21 is the manipulated variable u
An adder that adds II and I22' outputs the final manipulated variable 10(u,). 22 is the manipulated variable u 22 and ul
+', the final operation amount 1 no (u2
) is output.

Next, the operation of the controller 9 having such a configuration will be described.

The manipulated variable 10(u,) output from the adder 21 is PID
The other PID controller (C22) i 4 is controlled by the operation amount J7 (un) of the controller (Co) 13 and the multiplier 100.
The operation amount 2o (I22): is multiplied by a certain constant α, and the value l 02 (I22'=α・I22) is added (ul
= uo+u22') 10 L/.

Furthermore, the manipulated variable z1(u
2) is PID controller (C22) 14 hours operation amount 20
Cuz□) and multiplier 10, the other PID regulator 1
Add the value 1os(11,,'-β・Ul,) obtained by multiplying S-17(un) by a certain constant β from step 3 (u2-I
22+uII') becomes a value of 11.

With this configuration, the sub-loop system shown in FIG. 3, that is, the deviation signal 4 (e,),
I2) J s , operation t (ulz) 19 .

Loop system of adder 22 and manipulated variable 11 and deviation signal? issue&
(e2), PID controller (C22) 16. Operation to amount (
I22) 18 + adder 2 and operation amount 10 (ul
) ``'+ This can be shown using continuous time system arithmetic expressions as follows.The symbol S is the Laplace operator.

The manipulated variables ill and 112 in FIG. 3 become S & Matsu and ゛0fuset+, respectively. The first term of each is the main loop operation, and the second term is the subloop operation. However, PID controller C1j
(i=1.2.j''1.2), the gain was Kpij, the integration time was Ti1j, and the differential time was Tdij.

The manipulated variables ul+u2 in FIG. 4 are respectively . α and β are multipliers (M, , M2) 100°10
This is a constant set to 1.

The system in Figure 3 is achieved using equations (1) and (2), and (3).

(4) Comparing the system shown in Figure 4, which is made with 2,
The number of fA node parameters can be reduced from 12 (Figure 3) to 8 (Figure 4). moreover,
Even if the number of adjustment parameters is reduced, the effect of the second term in equations (1) and (2) can be reduced to (3) by directing α and β.
, By reducing the number of parameters, adjustment parameters, and meters implemented in the second term of equation (4,), it is possible to save time for parameter adjustment. .

As mentioned above, in order to simplify the explanation, we will use two-man power, two-man power,
Although the explanation has been made for an output system, the same applies to a general m-input, 9m-output system. In this case, conventionally, the number of parameters to be adjusted is 3·n? However, in the present invention, the number is m·(20m), which enables a significant reduction.

Next, a specific example in which the present invention is applied to a heat pump type air sublimation machine capable of heating and cooling will be explained with reference to FIG. FIG. 5 corresponds to the controlled object 12 in FIG. 1.

First, the configuration and operation of the controlled object shown in FIG. 5 will be described.

The compressor of the air conditioner is driven by an inverter, and the throttling mechanism is a reversible expansion valve 504, so that the indoor temperature and degree of superheat can be arbitrarily controlled. First, in the case of heating operation, the refrigerant compressed in the compressor 501 passes through the four-way valve 502 and is condensed in the indoor heat exchanger 5OS (operating as a condenser), as shown in the figure. The condensed refrigerant is then transferred to the reversible expansion valve 50.
4, the refrigerant expands adiabatically, evaporates in the outdoor heat exchanger 505 (acting as an evaporator), passes through the four-way valve 502 again, returns to the compressor 501 via the accumulator 506, and returns to the compressor 501. 5
When condensed at 03, a heating effect is obtained.

Next, we will discuss the case of cooling operation. The flow of refrigerant at this time is indicated by →.

That is, the refrigerant compressed by the compressor 501 passes through the four-way valve 502 and is condensed in the outdoor heat exchanger 505 (operating as a condenser). The refrigerant condensed here is adiabatically expanded in the reversible expansion valve 5θ4, and is
It is evaporated in the four-way valve 502 (which operates as an evaporator) and returns to the compressor 50 via the accumulator 506. Therefore, in this cycle, when the refrigerant evaporates in the indoor heat exchanger 503, a cooling effect is obtained. Here, the induction motor of the compressor 501 is driven by an inverter 507, and its drive frequency command value is 50.
8 is given. The reversible expansion valve 504 is given an opening degree by its opening command value 525, and the refrigerant flows in accordance with the opening degree.This controlled object is further provided with temperature detectors 510, 511° and 512, respectively. Indoor heat exchanger 50
3. Attached to the outdoor heat exchanger 505 and the suction pipe of the compressor 501. Signals 513, 514, and 615 from these temperature detectors are input to a calculator 509, which calculates the degree of superheat SH and outputs a degree of superheat signal -516. The arithmetic unit 509 has the configuration shown in FIG. 6, and its operation is as shown in the following. That is, the suction pipe temperature (Tsuc) 514 and the outdoor heat exchanger temperature (TLOUT
) 513 is performed by the subtractor 520, and the subtracted value is 521 (this value approximately indicates the degree of superheating 8HH during heating. That is, SHH = T'8 [C-Ty, ouT)
It is. On the other hand, the subtractor 522 calculates the suction pipe temperature (Tsuc
) 5 J 4 to indoor heat exchanger temperature (TLt-+05
15, and the subtracted value is 523 (this value approximately indicates the degree of superheating SHC during cooling. That is, SHC = Tsuc
-TLIN). 524 is a switching device, which outputs the superheat degree 8HH of the subtraction value 52 as the superheat degree signal 8H to the output line 516 during heating, and outputs the superheat degree SHC of the subtraction value 523 as the superheat degree signal 8H to the output line 516 during cooling. 516
Output to. Furthermore, another point is that an indoor air temperature (TIN) 518 is detected by a temperature detector 517 installed at an appropriate position on the indoor side where the air is conditioned.

The above is the configuration and operation of the air conditioner as the controlled object 12. This will be viewed from the perspective of the control system in comparison with Figure 1. That is, the manipulated variable 10.11 to the controlled object becomes the frequency command direct 5θ8 and the opening command value 525, and the output signal 2°6 is the indoor air temperature (TIN) 61B.
, superheat degree signal (SR) 51e. Set value signal 1,
5 are the set value of the indoor air temperature (TIN) and the set value of the superheat degree signal (SH), respectively. Furthermore, the deviation signal 4.8 indicates the deviation between the set value of the indoor air temperature (Tni) and the indoor air temperature (TIN), and the deviation between the set value of the superheat degree signal (8H) and the superheat degree signal (SH), respectively. represent. In this way, the multivariable control system (in this case, two
A two-output human output control system) is constructed.

Here, in the conventional case, the control method of this multivariable control system (configuration of the controller 9 shown in FIG. 1) is either shown in FIG. 2 or FIG. 3. Since the object to be controlled is an interference system (this is a fact confirmed experimentally), the method shown in Fig. 3 must be used. However, in the present invention, by using the method shown in FIG. 4, the controller becomes simpler, and as mentioned above, the adjustment time is shortened by reducing the number of parameters. This is equivalent to the conventional method.

As described above, according to the present invention, as a controller installed in a multivariable control system with m inputs and m outputs in which the controlled object is an interference system, the main loop system that directly influences the output of the controlled object The number of PID adjusters was reduced by providing a PID adjuster only for the PID adjuster and a multiplier for the sub-loop system that indirectly affects the system, so the number of parameters to be adjusted was reduced from the conventional 3tr? It is possible to provide a control device that can reduce the number of units to m (20 m), thereby simplifying the configuration and reducing the effort required for adjusting parameter values.

[Brief explanation of drawings]

Figure 1 is a system configuration diagram showing an example of a multi-variable control system with two people and two outputs, and Figure 2 is a block diagram showing the configuration of a conventional non-interference system used as the controller in Figure 1. Figures 3 and 3 are the same (block diagram showing the configuration of a conventional interference system, Figure 4 is a block diagram showing the configuration of a controller in an embodiment of the present invention, and Figure 5 is a block diagram showing the configuration of a controller in an embodiment of the present invention). FIG. 6 is a block diagram showing the configuration of the arithmetic unit shown in FIG. 5. 3.7... Subtractor, 9... Controller, 12... Controlled object, 13.14... PrD regulator, 21.22...
- Adder, 100, 101... Multiplier. Applicant's sub-agent Patent attorney Suzue Takehiko S'T1 π
1 2111 Figure 4 Figure 6

Claims (1)

[Claims] A main loop system that receives a plurality of output signals output from a controlled object, which is an interference system, and directly influences the output of the controlled object based on these signals, and a sub-loop system that indirectly influences the output of the controlled object. a controller that performs predetermined calculations and provides a plurality of manipulated variables as input signals to the controlled object; A control device 0 in a multivariable control system characterized by comprising a multiplier provided corresponding to the