Systems Engineering Department Examples of Control Systems Dr

Systems Engineering Department Examples of Control Systems Dr. Mansour Al-Dajani

Temperature Control. 1 Before we can control the temperature, we need to measure it first !!!

Temperature Measurement A. Resistance Temperature Device (RTD) Resistance of some metals change linearly with temperature: Resistance change can result in voltage/current change Input Volt Output Volt R

B. Thermistor Same as RTD except that relation between resistance and temperature is exponential: Again, resistance change can result in voltage/current change Input Volt R Output Volt

B. Thermocouple • Coupling of some metals can result in change in voltage when temperature changes at the junctions Junction Metal A T 1 T 2 Metal B + V -

Implementation of Thermocouple B T 1 (measuring end) ICE A B T 2=0 (reference end) Voltage is directly proportional to the temperature at the measuring end (T 1)

Air Pump Temperature Sensor u Computer ROOM Control Strategy Desired Temperature e Actual Temperature

Examples of Control Strategies 1. ON/OFF ON the bump 1. if actual > desired : Turn ? ? OFF the bump 2. if actual < desired : Turn ? ? 2. Proportional Control signal is proportional to the error between desired and actual u=Ke

Control of Assembly line. 2 • Objective: Use computer systems to control the sequence of operations in an assembly line • Tools: – Sensors – Actuators – Controllers (Computers)

Typical assembly line Machine 1 Power Machine 2 Power Fill Package Product Conveyer Motor Power

Position Sensors a. Switches + Vout Voltage Source • Switches ON/OFF electrical circuit • Used in many applications (e. g. assembly lines, level control, etc. ) • Two types: Normally Open (N/O) Normally Close (N/C)

b. Push buttons Normally Open (N/O) Normally Close (N/C)

c. Photo-emitter detector pair: – Consists of one light emitter and one light detector • Light emitter • Light detector – Detects objects crossing the beam – Applications: supermarket gates, production assembly line, etc. Light emitter Light detector Light reflector (e. g. mirror)

Level Sensors Light emitter Light detector

Control Machine 1 Power Machine 2 Power Package Fill Level Sensor Switch 1 Switch 2 Conveyer Motor Power