JPH0330166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling various processes such as air conditioners and production equipment.

[Conventional technology]

When controlling various processes, control variables such as flow rate, pressure, temperature, humidity, etc. are detected using various sensors, and these detected quantities are sampled at regular intervals. This method averages a predetermined number of N pieces of data, sends out a trigger pulse that commands control based on this average value, performs control calculations using the average value, and performs control according to this result. is becoming common.

[Problem that the invention seeks to solve]

However, because N pieces of data are always averaged and control is repeated according to the average value, sudden or temporary changes in the control amount are removed, and the control state becomes stable. Fluctuations in the control amount in response to changes in the control amount are also averaged out, causing a problem in which control response is delayed and followability of the control situation is degraded.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention is constructed by the following means.

That is, in the above control method, the predetermined number N
Find the average value m ₁ of data from the present to the past for a plurality of n pieces smaller than 1, and k
The average value m ₂ of n pieces of data from the past to the past is calculated, and when the difference between these average values m ₁ and m ₂ is greater than a certain value, it is considered that a sudden change has occurred. If the direction of change of these data is the same as the direction of change of the difference between m ₁ and m ₂ , find the average value m ₃ of the current data and l pieces of data, and add this average value m ₃ to A trigger pulse is sent out to instruct control based on the above.

[Effect]

Therefore, the average value m ₁ obtained by averaging the n pieces of data closest to the present, and the past data n
If the difference from the average value _m2 obtained by averaging the data exceeds a certain value, it is determined that a sudden change has occurred in the controlled variable, and further sampling is performed to obtain l data. The direction of change is the average value
If the direction of change is the same as the difference between m ₁ and m ₂ , it is determined that the changing state is not temporary, and the average value m ₃ of l data and these immediately preceding data is calculated.
Based on this, a trigger pulse is sent to command control, and while sudden or transient changes that do not affect the average values m ₁ and m ₂ are ignored, rapid and continuous changes Since the control based on the average value m ₃ is immediately performed in response to a change in the control amount, the responsiveness of the control to sudden and continuous fluctuations in the control amount is improved.

〔Example〕

Hereinafter, details of the present invention will be explained with reference to figures showing examples.

Figure 2 is a block diagram of the control device, which includes a processor such as a microprocessor (hereinafter referred to as CPU).
1, fixed memory (hereinafter referred to as ROM) 2,
Variable memory (hereinafter referred to as RAM) 3 and interfaces (hereinafter referred to as I/F) 4 ₁ to 4 ₄ are arranged around it, and these are connected by a bus bar, and I/F 4 ₁ receives detection signals from various sensors, etc. The output is given as input data _D1 , and from I/ _F42 , for example, a refrigerator,
Control signals for each device to be controlled, such as a pump, are sent out as output data D _p .

In addition, a higher-level device such as a central control unit is connected to the I/F 4 ₃ via a transmission line 5, and data signals are also sent and received via the I/F 4 ₃ , and basic control data given from the higher-level device is transmitted and received. At the same time, data indicating the control status is sent for monitoring purposes.The I/F _{4 4} is equipped with terminal equipment (hereinafter referred to as TE) 6 such as a display such as a cathode ray tube display and a keyboard. By operating the TE 6, data is stored and updated in the RAM 3, and the status of these and control status is displayed by the TE 6.

Here, the CPU 1 executes the instructions in the ROM 2, samples the input data D _i via the I/F _{4 4} as a detection amount at a constant cycle, sequentially stores this data in the RAM 3, and also A calculation is performed to find the average value, and upon completion of this, a trigger pulse is sent out, this is used as an opportunity to perform a control calculation, the result of this is sent as output data D _p , and the control based on this is repeated. However, in addition to this, the calculations and controls shown in FIG. 3 are also performed, and when these are executed, the calculations and controls are performed while accessing the necessary data to the RAM 3.

That is, FIG. 3 shows a sampling situation and an average value calculation situation when, for example, pressure P is the detected quantity. Pressure P is sampled at a constant period _t0 , and normally the average value of a predetermined number of N pieces of data is calculated. When this is completed, a trigger pulse is sent out at time _t1 , but in addition, if _t2 is the current time, the relationship N>n is satisfied, and n pulses are sent from the present to the past. Average value based on data of
In addition to finding m ₁ , find the average value m ₂ of n pieces of data from the past k from the present, and if the absolute value of the difference between each average value m ₁ and m ₂ is greater than a certain value C, there is no sudden change. It is determined that the difference between m ₁ and m ₂ is increased or decreased.

Next, continue sampling to obtain l pieces of data, and if the direction of change of each of these data is the same as the direction of change of the difference between m ₁ and m ₂ , it can be concluded that the sudden change is not temporary. If this point is set as t ₃ , then the average value m ₃ of l pieces of data in the past and the data at time t ₂ is calculated, and control is performed based on this. At time t ₃ , the trigger pulse is The control situation is determined by a control calculation based on the average value _m3 .

FIG. 1 is a flowchart of the control situation mainly between time points t ₁ and _{t 3} in FIG. ?”101 is Y
(YES), “OND determination based on changes in the number of operating units and control amount” 102 is performed, a standby time OND is determined to stop the next start and stop control until the control amount is stabilized, and the control amount is changed. "Averaging prohibition flag set at startup" 103 is performed to prohibit average value calculation using sampling data that is changing.

When step 101 is N (NO), step
In response to Y of 104 "OND progress?", "inhibition flag reset" 105 is performed in correspondence with step 103.

Next, when determining the number of operating units described above, if there are operating units that will be stopped, “ON → OFF?” 111 will be changed to Y.
Then, by "Determining OFD according to the number of operating units and changes in control amount" 112, a waiting time OFD is determined to stop the next start and stop control until the control amount is stabilized. Perform prohibition flag set"113.

Also, if step 111 is N, step 114
In response to Y of "OFD progress?", "inhibition flag reset" 115 is performed in correspondence with step 113.

Next, depending on the flags in steps 103 and 113,
Check “Averaging prohibited?” 121, and if this is N, has a certain period t ₀ elapsed? ``122 Sampling the input data D _i according to Y'' 123 is performed, and the minimum number of samples n+k required to calculate the average values m ₁ and m ₂ ? "In response to Y of 124, the flag described below will indicate "Changing? Check 125 and this is N
When , each average value “m ₁ , m ₂ calculation” in Figure 3
131, and determine "|m ₁ - m ₂ | C?" 132. If the difference between m ₁ and m ₂ is greater than a certain value C, the result is Y, indicating that a sudden change has occurred. Therefore, after performing the "change flag set" 133 corresponding to step 125, the "change sign flag" indicating whether the sign of the difference between m ₁ - _{m 2} is positive or negative is set.
Perform "SET" 134.

On the other hand, the flag at step 133 causes the step 125 to
If is Y, the current data D _i and the previous data
Calculate “e=D _i-1 ”141 using D _{i -1} , and _step
Based on 134 and 141, judge whether the direction of change in both is the same or not, and judge that it is still changing according to Y of this, and if "Number of samples = l?" 143 becomes Y,
After performing the average value "m ₃ calculation" 151 in _FIG .
m ₂ | Change N to N _t according to "153, ROM2
Alternatively, use the conversion table in RAM3 to find _Nt .

On the other hand, when any one of steps 124, 132, and 142 is N, it is considered a stable state, and the step
Corresponding to step 133, "change flag reset" 161 is performed, and the flag at step 152 indicates "N changing?"
162, and if this is Y, make a judgment of “Number of samples N _t ?” 163, if N, make judgment of “Number of samples N?” 164, and depending on these Y,
Select “MAX/MIN” to specify whether to exclude the maximum and minimum values set by TE6 in advance.
Katsuto? ” 171, it is judged according to the contents of RAM 3, and if it is Y, “average value calculation excluding MAX and MIN” 172 is performed, and according to N in step 171, “N average value calculation” 173 is performed. After doing it,
Corresponding to step 152, "N change flag reset" 174 is performed, and the average value from steps 172, 173 or 151 is changed to "average value → control calculation" 181.
Store it in RAM3 as data for control calculation,
``Trigger pulse sending'' 182 is performed, the process moves to a control calculation routine via ``EXIT'', and steps 101 and subsequent steps are repeated through each of these routines.

Therefore, while sudden or temporary changes in the range that do not affect the average values m ₁ and m ₂ are not detected, rapid and continuous changes are detected, and furthermore, this change is not temporary. This is confirmed, and in response to this confirmation, control in the event of a sudden change based on the average value m ₃ is performed immediately, and the number of samples N at the time of the sudden change and during the subsequent averaging calculation is changed, so that the response is Prompt and stable control of sex is achieved.

However, the numbers of n and k are N>n>k and N?
n + k), which can be selected according to the conditions, and l
The same applies to the number of detection quantities, and various physical quantities may be used as the detection quantity depending on the purpose.

Moreover, the equipment to be controlled can be arbitrarily selected according to the control amount, and can be applied not only to control of the number of operating units but also to capacity control, etc.

In addition, the configuration in Figure 2 can be selected depending on the situation, and in Figure 1, according to the conditions,
The present invention can be freely modified in various ways, such as changing the order of the steps, replacing them with other equivalent steps, or omitting unnecessary steps.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, sudden or temporary changes in the detected amount are ignored, while sudden and continuous changes are detected and confirmed, and control based on the average value is immediately performed. Since control is performed stably and with high responsiveness, remarkable effects can be obtained in various types of control based on various detected amounts.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention; FIG. 1 is a flowchart of a control situation, FIG. 2 is a block diagram of a control device, and FIG. 3 is a diagram showing a sampling situation and an average value calculation situation. 1...CPU (processor), 2...ROM (fixed memory), 3...RAM (variable memory), 4 ₁ to 4 ₄ ...
...I/F (interface), P...pressure (detected amount), _m1 to _m3 ...average value, C...constant value.

Claims (1)

[Claims] 1. Sampling the detected amount at a constant cycle,
In a control method that calculates the average value of a plurality of N pieces of data obtained in this manner, updates each data every sampling period, and sends out a trigger pulse that commands control based on the average value, normally, Sends a trigger pulse that instructs control based on the average value of the latest N pieces of data including the current sampling data, and calculates the average value m ₁ of a plurality of n pieces of data from the present to the past, which is less than the above N pieces. At the same time, calculate the average value m ₂ of the n pieces of data from the past k pieces to the past, and calculate each of these average values m ₁
When the absolute value of the difference _between
If the direction of these changes is the same as the direction of change of the difference, it is determined that a non-temporary sudden change has occurred, and when this non-temporary sudden change occurs, the average value
Find the average value m ₃ of the sampling data when the absolute value of the difference between m ₁ and m ₂ is determined to be above a certain value and the past l pieces of data, and command control based on the average value m ₃ A control method characterized by sending out a trigger pulse.