INTRODUCTION OF CONTROL SYSTEM
1.4 ANALYSIS AND DESIGN OBJECTIVES
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Elevator
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Furnace
Automative engine (plant)
Input: Desired heat
Control System: Fuel valves and actuator
Output: Actual heat
Input: fuel rate & pump rate
Output: shaft speed
A control system responses to an input by undergoing a transient response before reach a steady state
3 Main objective in designing control system
Transient response
Too fast = uncomfortable
Stability
Too long = booring
Steady State Response
consistent output = may cause injury
steady state error has to be small
Only exist in stable system
1.5 OPEN LOOP AND CLOSE LOOP
1.2 CLASSIFICATION OF CONTROL SYSTEMS
1.3 ADVANTAGES OF CONTROL SYSTEMS
Open loop System
Close loop system
open loop system is that it cannot compensate for any disturbances that add to the controller driving signal.
Example Open loop system:
Classification based on the mathematical
model of the system
A system mechanical or electronic device that automatically regulates a system to maintain a desired state or set point without human interaction.
Example close loop system:
Classification based on groups
Classification based on type of signals used
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P.A System
Toaster
Light switch
Continuous control systems
Tv remote control
Discrete type control systems
Cruise control
Washine machine water level
Elevator
Advantages:
Simplicity
Low-cost
Easy maintenance
Disadvantages
step 3: Transform the physical system into schematic diagram
step 4: Development of mathematical modelling
step 2: Draw functional block diagram
step 5: Block diagram reduction
step 6: Analysis and design
Poor Reliability
Poor Flexibility
Can't handle disruption
Advantages and disadvantages
Advantages
Disadvantages
Flexible and Faster Recovery
Continuos Improvement
Reliable and accurate
Required heavy documentatation
expensive and exclusive
costly and intensive training
signals that are used in
subsystems and components are in discrete or digital form
Power Amplification
signals that are used in
subsystems and components is in time domain, t
Remote Control
Convenience of Input Form
Linear control systems
Compensation for Disturbance
Several tool/techniques can be used to solve the control problems
Is always used during the analysis and design phase
Example: DC motor
An ideal system
in moving the radar antenna position to certain angle, small input power is amplified to produce high output torque
Non-linear control systems
step 1: Transforming the requirements into physical system and design specifications
Systems that normally exist in the real world and difficult to
analyze
No general method to find the control solution
Approximations are normally made so that the system behaves like
a linear system to allow analysis and design
Example: AC motor, inverted pendulum
in controlling the movements of robots working in contaminated areas where human presence should be avoided
in a temperature control system, the turn of a knob corresponds to certain desired room temperature exp: thermostat
to maintain antenna position in the presence of strong wind
Kinetic (tracking) control systems
Process (regulating) control systems
Fast system response with small delay time
Control variables: displacement/position, speed, acceleration
Input may be fixed or changing
Normally involves electrical or hydraulic manipulators
Slow system response with large delay time
System responds to a fixed set point
Control variables: temperature, flow, level, pressure
Examples of manipulators include pneumatic manipulators
and heating elements
1.1 INTRODUCTION
Basic elements of control system
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Control system is an interconnection of components forming a
system configuration to provide a desired system response.
Controller
Input
Plant
Output
NATURAL –WITHIN HUMAN BODY
NON PHYSICAL WORLD
MAN MADE CONTROL SYSTEM
CD player, radio antenna, rockets/missiles, robots, oven, and
room air conditioner
automatic control of a student performance
adrenalin increases along with our heart rate, causing more oxygen to be delivered to our cell
Malfunction of control systems can lead to accidents
ahli: amirul aiman, khairi hafizin, fatin haziqah, arissa balqis, aina qistina