The temperature of the passenger compartment differs considerably depending on the place
where it is measured. Instead of using multiple sensors for temperature measurement and
averaging the measured values, it is economical to install a small suction blower at the place where
passengers normally sense the temperature. The temperature of the air from the suction blower
is an indication of the passenger compartment temperature and is considered the output of the
system.
The controller receives the input signal, output signal, and signals from sensors from
disturbance sources. The controller sends out an optimal control signal to the air conditioner or
heater to control the amount of cooling air or warm air so that the passenger compartment
temperature is about the desired temperature.