Open and Closed Loops Standard Grade Computing Studies

Sensors Infra Red Heat Pressure CLOSED LOOPS (=sensors + feedback) The devices at the other end are OUTPUT DEVICES System Alarms Lights Motors System Sensors are INPUT DEVICES

Sensors Infra Red Heat Pressure CLOSED LOOPS (=sensors + feedback)

Sensors Infra Red Heat Pressure feedback CLOSED LOOPS (=sensors + feedback)

Sensors Infra Red Heat Pressure feedback Microprocessor: (decision) CLOSED LOOPS (=sensors + feedback)

Sensors Infra Red Heat Pressure feedback Microprocessor: (decision) Control Signal

Sensors Infra Red Heat Pressure feedback Microprocessor: (decision) Control Signal

Sensors feedback

Sensors feedback Microprocessor: (decision) In box at side of traffic lights

Sensors feedback Microprocessor: (decision) In box at side of traffic lights

Sensors feedback Microprocessor: (decision) In box at side of traffic lights Control signal changes lights Driver sees signal to make CLOSED LOOP

End Effector (Gives adaptability) Degrees of freedom 10// This is a simple program 20REPEAT 30UNTIL INPUT 2 IS ON 40SWITCH OUTPUT 3 ON 50REPEAT 60UNTIL INPUT 1 IS ON 70SWITCH OUTPUT 3 OFF 80END Control Program (to run the robot) Stored in ROM

10// This is a simple program 20REPEAT 30UNTIL INPUT 2 IS ON 40SWITCH OUTPUT 3 ON 50REPEAT 60UNTIL INPUT 1 IS ON 70SWITCH OUTPUT 3 OFF 80END Control Program (to run the robot) Stored in ROM Translated into machine cod A system which has its software built into a micro processor is an example of embedded technology

Digital signals - pulses Analogue signals - continuous The analogue signals of the real world have to be changed into digital signals of the computers world

10// This is a simple program 20REPEAT 30UNTIL INPUT 2 IS ON 40SWITCH OUTPUT 3 ON 50REPEAT 60UNTIL INPUT 1 IS ON 70SWITCH OUTPUT 3 OFF 80END Different ways to program machines 1 2 3