Separation Principle. Controllers & Observers Plant Controller Observer Picture.
Pre Chapter 4 - Controller Principle (2)
-
Upload
ahmad-tirmizi -
Category
Documents
-
view
76 -
download
0
description
Transcript of Pre Chapter 4 - Controller Principle (2)
![Page 1: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/1.jpg)
EJ 301: BASIC CONTROL SYSTEM
CHAPTER 4: CONTROLLER PRINCIPLE
![Page 2: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/2.jpg)
BASIC PRINCIPLES OF CONTROLLER
![Page 3: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/3.jpg)
Function of Controller
To stabilize the system where the system will hold the set point and not swinging around.
![Page 4: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/4.jpg)
TERM DEFINITIONERROR - Difference between a set point and the process value.
VARIABLE RANGE - Range of values within which the control is required to be maintained.
CONTROLLER OUTPUT RANGE
-Range of the output from the controller.-The controller output expressed as percentage.
CONTROL LAG -The time for the process-control loop to make necessary adjustment to the final control element
DEAD ZONE -The amount of time it takes for the process variable to start changing after changing output as a control valve, variable frequency drive etc.
Properties of Controller
![Page 5: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/5.jpg)
CLASSIFICATION OF CONTROLLER
![Page 6: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/6.jpg)
General Classification of Controller
Figure 4.1: Flow chart of classification of controller
![Page 7: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/7.jpg)
Definition.• Discontinuous control system are nonlinear
system.• The input and output properties are based on
the approximate describing function method.
Discontinuous Controller Mode
![Page 8: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/8.jpg)
Two-position mode• compares the value of an analog or variable input
with instructions and generates a digital output.
• Also known as ON-OFF Controller.
• The output changes its values as the input crosses these limit values.
• Applications:- temperature control, relative humidity, liquid level.
![Page 9: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/9.jpg)
Figure 4.2: Example of Two-position mode
![Page 10: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/10.jpg)
Multi-position controller.• Manage multiple loads.
• Controller works as the selector.
• Applications: Fans, dampers, heater.
![Page 11: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/11.jpg)
Figure 4.3: Example of Multiple-position mode
![Page 12: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/12.jpg)
Definition.• The system which are not sufficient to use
discontinuous control mode.• Classified as proportional controllers, integral
controllers and derivative controllers.• Example: controlling steam flow system.
Continuous Controller Mode
![Page 13: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/13.jpg)
Types of Continuous control TYPESITEMS
PROPORTIONAL CONTROL MODE
INTEGRAL CONTROL MODE
DERIVATIVE CONTROL MODE
![Page 14: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/14.jpg)
CONTINUOUS CONTROLLER MODES
![Page 15: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/15.jpg)
COMPOSITE CONTROL MODES
![Page 16: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/16.jpg)
DEFINITION• The system that involves the measurement of the
offset or error over time.
• This error is integrated and a adjustment is made to the output signal from the proportional part of this model.
PROPORTIONAL + INTEGRAL MODE (PI CONTROL MODE)
![Page 17: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/17.jpg)
PROPORTIONAL + DERIVATIVE MODE (PD CONTROL MODE)
![Page 18: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/18.jpg)
Definition• A proportional–integral–derivative controller (PID
controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems.
• A PID controller calculates an "error" value as the difference between a measured process variable and a desired set point.
• The controller attempts to minimize the error by adjusting the process control inputs.
PROPORTIONAL + INTEGRAL + DERIVATIVE MODE (PID CONTROL MODE)
![Page 19: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/19.jpg)
ADVANCE CONTROL TECHNIQUES
![Page 20: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/20.jpg)
Definition• Uses the output of the primary controller to manipulate the
set point of the secondary controller.
Characteristics
CASCADE CONTROL
![Page 21: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/21.jpg)
Definition.• Feed-forward is a term describing a kind of system which
reacts to changes in its environment, usually to maintain some desired state of the system.
FEED FORWARD CONTROL
![Page 22: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/22.jpg)
Definition.• Ratio control is used to ensure that two or more flows are
kept at the same ratio even if the flows are changing.
RATIO CONTROL
![Page 23: Pre Chapter 4 - Controller Principle (2)](https://reader030.fdocuments.in/reader030/viewer/2022032623/55cf9d1d550346d033ac4c12/html5/thumbnails/23.jpg)
Definition.• Adaptive Control is the control method used by a controller
which must adapt to a controlled system with parameters which vary, or are initially uncertain.
• For example, as an aircraft flies, its mass will slowly decrease as a result of fuel consumption; a control law is needed that adapts itself to such changing conditions.
ADAPTIVE CONTROL