Controller -- Noise
From SysCAD Documentation
Navigation: Main Page -> Models -> Process Control Models
Contents |
General Description
- This unit operation is used to simulate process noise. It can be used to add disturbance to Feeders, pipe outlet capacity and other writeable variables.
- The Noise Control model is an orphan model, i.e it cannot be connected to any other unit operation.
- The noise model is for dynamic simulation only with the purpose of adding disturbance to the model.
Diagram
The diagram shows the default drawing of the Noise control unit.
Inputs and Outputs
There are no connections to this unit.
Model Theory
The Probability Density functions used for the Noise generation are as follows:
- Gaussian - Probability Density Function (P(t)):
- Flat - Probability Density Function (P(t)):
- P(t) = 0
- where t < Tavg - dev or t > Tavg + dev
- where Tavg - dev <= t <= Tavg + dev
- P(t) = 0
- Weibull - Probability Density Function (P(t)):
- This random number generator uses a (mean) and b (standard deviation) to determine the output number.
- where
.
- U is a randomly generated number between 0 and 1
Data Sections
The default sections and variable names are described in detail in the following tables. The default Noise Controller access window consists of 2 sections. This number may increase or decrease, based on user configuration.
- The first section, which has the same name NoiseCon, contains general information relating to the unit.
- The Info section contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
Class: NoiseCon - The first tab page in the access window will have this name.
|
Tag / Symbol |
Input / Calc |
Description/Calculated Variables / Options |
|
On |
Tick box |
Enable or disable all of the independent Noise Blocks. |
|
ShowCnv |
Tick box |
|
|
No_of_Blks |
Input |
The number of independent Noise blocks required. This may be any number from 0 upwards. The user may also change this number at any time. However, the unit will always add new noise blocks after existing ones, and it will delete them starting from the last block. E.g. if you have 5 noise blocks set up and you change this to 4, noise block number 5 will be deleted. So if you do not want noise block number 1, the best way is to turn this off individually or use the priority field to change its display order. |
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| ||
|
Check Tags |
Button |
SysCAD will perform a check on the validity of the tags used. |
|
| ||
|
State |
Output |
The state of the noise block. If everything is correct and operating normally, the user will see 'OK' in this box. Otherwise the unit will flag an error message, which helps the user to locate the problem. |
|
MSG_1 to MSG_2 |
Output |
Any errors will be reported here. These messages are also displayed in the message window. |
|
Each independent noise block has the following layout. If there is not enough space to display all blocks on the first tab page, a second tab page will be created. | ||
|
Tag.Cfg.[Noise Block number] | ||
|
Type |
List Box |
Gaussian Distribution method as described in the Theory above. 68.27% of the numbers generated will be between (Mean - StdDev) and (Mean + StdDev). |
|
Flat Distribution method as described in the Theory above. | ||
|
Poisson distributed random deviates Method. | ||
|
Gamma-law distribution random deviates Method. | ||
|
Weibull Distribution method as described in the Theory above. | ||
|
Output_Tag |
Input |
This is the manipulated variable. Eg: XPG_1.Qm_Rqd (kg/s) or P_1.Qm_Capacity (kg/s). Note: only white, changeable data fields can be used here. |
|
Output |
Calc |
The output value. |
|
On |
Tick Box |
Enables or disables the independent Noise Blocks. |
|
Mean / a |
Input |
Mean - The value around which the random number must be generated. If Weibull Distribution is used, a (for alpha parameter) will be displayed |
|
StdDev / b |
Input |
StdDev - The standard deviation. Used with Gaussian and Flat Distribution methods. If Weibull Distribution is used, b (for beta parameter) will be displayed |
|
ExecCnt |
Input |
The number of iterations between each step change. So, a small value here means that the output will change frequently, while larger values mean that the output changes more slowly. |
|
IterCnt |
Display |
The total number of iterations that the Noise controller has been active. |
|
Priority |
Input |
If more than one noise block is used, the user may set the priority of the blocks. This changes the order of the blocks are displayed. If the user wants to delete an unwanted block, assign it with the lowest priority (thus the largest number) to move it to the last position. The delete it by change the number of blocks number to x-1. |
Adding this Model to a Project
Insert into Configuration file
Sort either by DLL or Group.
|
|
DLL: |
Control1.dll |
→ |
Units/Links |
→ |
Control: Noise |
|
or |
Group: |
General |
→ |
Units/Links |
→ |
Control: Noise |
See Project Configuration for more information on adding models to the configuration file.
Insert into Project
|
|
Insert Unit |
→ |
Control |
→ |
Noise |
See Insert Unit for general information on inserting units.
