Control System - Elements

COMPONENTS OF CONTROL SYSTEM

Introduction to Control System Components

BLOCK DIAGRAM OF CLOSED LOOP CONTROL SYSTEM

Closed-loop systems are designed to automatically achieve and maintain the desired output condition by comparing it with the actual condition.

BASIC ELEMENTS OF CONTROL SYSTEM ARE

• Error Detector

• Amplifier & Controller

• Actuator

• Plant

• Sensor And Feedback System

ERROR DETECTOR

It compares the feedback signal with reference input and determines the error signal also known as actuating signal.

CONTROLLER

• It consists of control logic elements.

• The error detector may be also be considered as part of controller.

CONTROL LOGIC ELEMENT

• It manipulates the error signal or actuating signal.

• It produces the desired signal to be applied to system.

DIFFERENT TYPES OF CONTROLLER

• ON -OFF CONTROLLER

• PROPORTIONAL CONTROLLER

• PI (PROPORTIONAL INTEGRAL) CONTROLLER

• PD (PROPORTIONAL DERIVATIVE) CONTROLLER

• PID (PROPORTIONAL INTEGRAL DERIVATIVE) CONTROLLER

ON - OFF CONTROLLER

Example: Auto switch off motor when tank is full.

PROPORTIONAL CONTROLLER

Example: PWM based controller for controlling rpm of a motor.

PI (PROPORTIONAL INTEGRAL) CONTROLLER

It is device that produces a control signal consisting of two terms: one is proportional to error signal and the other is proportional to integral of error signal.

PD (PROPORTOINAL DERIVATIVE) CONTROLLER

A PD controller is used to make a simple system track some reference point.

Example:

In the car suspension system, the spring and damper work together to hold the car at some desired height. The spring exerts a force proportional to its deflection, while the damper opposes motion (the derivative of deflection).

PID (PROPORTIONAL INTEGRAL DERIVATIVE) CONTROLLER

PID controller is an instrument used in industrial control applications to regulate temperature, flow, pressure, speed and other process variables.

They are the most accurate and stable controller.

Example:

PID temperature controller, has a temperature sensor (thermocouple) as input and compare the actual temperature to the desired control temperature. It will then provide an output to a control element.

Multiple Choice

PD CONTROLLER IS STANDS FOR

• PROPORTIONAL DERIVATIVE CONTROLLER

• PLUS DERIVATIVE CONTROLLER

• PROPORTIONAL DIFFERENCE CONTROLLER

Multiple Choice

PID STANDS FOR

• PLUS INTEGRAL DIFFERENCE

• PROPORTIONAL INTEGRAL DERIVATIVE

• PROPORTIONAL INTEGRAL DIFFERENCE

Poll

WHICH CONTROLLER IS STABLE AND ACCURATE

• PID

• PD

• PI

Multiple Choice

ERROR SIGNAL IS ALSO KNOWN AS ACTUATING SIGNAL

• TRUE

• FALSE

Multiple Choice

CLOSED LOOP SYSTEM DOES NOT HAVE FEED BACK IN IT

• TRUE

• FALSE

Multiple Choice

SENSOR IS USED AS WHICH ELEMENT

• CONTOLLER

• FEEDBACK

• PLANT

• ERROR DETECTOR

Multiple Choice

WHAT IS THE PURPOSE OF ERROR DETECTOR

• DETECTS THE ERROR BETWEEN DESIRED OUTPUT AND ACTUAL OUTPUT

• DETECTS THE ERROR BETWEEN PLANT AND CONTROL ELEMENT

• DETECTS THE BETWEEN REFERENCE INPUT AND CONTROLLING SIGNAL

THANK YOU ALL