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INTRODUCTION TO CONTROL SYSTEM
System Control System Examples of Control System History Of Control System Input & Output SISO & MIMO J.M.Martinez, Jr. School of EE-ECE-CoE Mapúa Institute of Technology 1 Open & Closed Loop System Feedback Characteristics System Representations Block Diagram Control Laws/Algorithms
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SYSTEM
An arrangement, set, or collection of things connected or related in such a manner as to form an entirety or whole. An arrangement of physical components connected or related in such a manner as to form and/or act as an entire unit.
CONTROL SYSTEM
An arrangement of physical components connected or related in such a manner as to command, direct, or regulate itself or another system. 2
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EXAMPLES OF A CONTROL SYSTEM
BATHROOM TOILET TANK
FLOAT WATER LEVEL
WATER SOURCE
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VALVE
STOPCOCK
TANK
As the tank is emptied through a stopcock, the valve opens filling the tank. When the tank becomes full, the float gets closer to the 3 top, closing the valve and so shutting the flow of water.
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BLOCK DIAGRAM OF A BATHROOM TOILET TANK
ERROR SIGNAL VALVE POSITION
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PRESET WATER LEVEL
(r)
(e)
(u)
ACTUAL WATER LEVEL
(c)
CONTROL LOGIC ELEMENTS
+
−
ACTUATOR
CONTROLLED SYSTEM
SOURCE & VALVE FLOAT & LINKAGE
WATER TANK DISTURBANCE FLOW
(n)
4
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STEAM ENGINE WITH CENTRIFUGAL GOVERNOR
PIVOT POINTS
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BALL
SLIDE ON SHAFT
BALL
TO STEAM ENGINE
SLIDE ON SHAFT
SHAFT DRIVEN BY ENGINE
5
BLOCK DIAGRAM OF A STEAM ENGINE WITH A CENTRIFUGAL GOVERNOR
DESIRED VELOCITY ERROR SIGNAL VALVE POSITION ANGULAR VELOCITY
(r)
+
(e)
(u)
(c)
−
CONTROLLER
CONTROLLED SYSTEM
STEAM ENGINE CENTRIFUGAL GOVERNOR
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HISTORY
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300 B.C.-LIQUID-LEVEL CONTROL. A water clock invented by
References: • Schaum’s Outline Series “Feedback and Control Systems”, 2nd edition, by DiStefano III, J.J., Stubberud A.R., and Williams I.J. • Control Systems Principle and Design, 2nd ed., by Gopal M., • Control Systems Engineering, 3rd edition, by Nise N.S. • Feedback Control Systems, 4th edition, by Philips C.L., and Harbor R.D. • Control System Design Lecture Notes for ME 155A, by Åstrom K.J. 33