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Control Theory (“Regeltechniek”). Jeroen Buijs jeroen.buijs@groept.be Module 8. The course. Lectures: Prepared Interactive Lectures… Written - Open book - Exercise exam + 0..4 bonus points Exercise sessions: 12*1,5h – permanent assessment (assignment) Lab: PLC
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Control Theory (“Regeltechniek”) Jeroen Buijs jeroen.buijs@groept.be Module 8
The course Lectures: Prepared Interactive Lectures… Written - Open book - Exercise exam + 0..4 bonus points Exercise sessions: 12*1,5h – permanent assessment (assignment) Lab: PLC OPO mark = 50% lect. / 20% exerc. / 30% lab
Prepared Interactive Lectures • All info on blog: http://grouptemcontroltheory.wordpress.com/ !!! You’ll need a Wordpress login !!! (Please choose a user name with your first and last name in it) • Preparation assignments appear on Wednesday (with a due date) up to 2 bonus points can be obtained by preparing evaluation is based on EFFORT PASSWORD for assignments: GTcontrol • In class, we work by means of poll questions/group tasks up to 2 bonus points can be obtained by answering evaluation is based on CORRECTNESS !!! You’ll need a Polleverywhere login and a voting device !!!
First examples http://www.youtube.com/watch?v=AZhQt7HOSWo http://www.youtube.com/watch?v=YnFlpxKVMTQ http://www.youtube.com/watch?v=uERF6D37E_o
First examples [PID Control Theory Made Easy, ABB]
First examples IBM’s DB2 Universal Database Management System [Abdelzaher]
First examples ROAD Desired direction Actuator/ Current direction Error
First examples SECOND EXAMPLE: See http://www.youtube.com/watch?v=8pPfrV8E37o&feature=player_detailpage
First examples ORIGIN OF AUTOMATIC CONTROL 1769: The first automatic controller with feedback in an industrial process Steam engine (James Watt?) Control system (called ‘fly-ball governor’)
First examples ORIGIN OF AUTOMATIC CONTROL Control system: ‘fly-ball governor’
First examples ORIGIN OF AUTOMATIC CONTROL Control system: ‘fly-ball governor’ 1- Turns with speed of output axis of the steam engine. 2- Speed of engine balls towards outside. 3- The movement of the balls regulates the valve of the incoming steam. Balls towards outside Valve closes Less steam speed
History of control theory • In the beginning: based on intuition/heuristics • Second half of 19th century: Mathematical descriptions (processes => control) • World wars: need for very accurate control systems (gun positioning, navigation) • the CLASSICAL control period (1914-1960) = design in the frequency domain (Bell laboratories) • 1960-now: MODERN control period = design in the time domain Remark: 1969: start of digital control era.
Feedback Example: Thermostatic control
Feedback Example: Thermostatic control PRINCIPLE: 0- Process: Room with in- and outgoing heat flows 1- Measurement: We measure the temperature in the room (T) 2- Comparison: Compare this with the desired temperature (TD) 3- Determine theControl action: If T < TD : Increase heat flow from heating element If T > TD : Decrease heat flow from heating element If T = TD : Don’t change anything 4- Actuate: Use a device to conduct the desired action e.g. increase temperature of water in central heating system Feedback principle:We use a measurement of the output of the process to determine what to do with the input of the process.
Feedback Closed loop / Feedback control system – Block scheme
(No…) Feedback Control system without feedback – Block scheme
Block scheme of Closed Loop “Servo problem” vs “Control problem”