As its name implies control engineering involves the design of an engineering product or system
where a requirement is to accurately control some quantity, say the temperature in a room or the
position or speed of an electric motor. To do this one needs to know the value of the quantity
being controlled, so that being able to measure is fundamental to control. In principle one can
control a quantity in a so called open loop manner where ‘knowledge’ has been built up on what
input will produce the required output, say the voltage required to be input to an electric motor
for it to run at a certain speed. This works well if the ‘knowledge’ is accurate but if the motor is
driving a pump which has a load highly dependent on the temperature of the fluid being pumped