Abstract: A vehicle air conditioning control system includes an actuator for controlling the position of an outside air intake door and an ambient exhaust gas sensor. A controller of the control system monitors a time rate of change of the degree of uncleanness periodically measured on the basis of the output of the sensor, and commands the actuator to bring the intake door to the fully closed position for the inside air recirculation mode if a first requirement about a previous exhaust gas concentration change and a second requirement about a current exhaust gas concentration change are both met.

Abstract: A computer-controlled automotive air conditioning system comprises an air conditioning unit which, when operated, produces a conditioned air fed to a passenger room of the vehicle. An outside temperature sensor, an inside temperature sensor, a temperature setter switch, a solar radiation sensor and an intake air temperature sensor are arranged for issuing first, second, third, fourth and fifth information signals. A computer-installed control unit is employed for controlling operation of the air conditioning unit in accordance with the first, second, third, fourth and fifth information signals. The computer is operated under a fuzzy system theory so that the magnitude of at least one of the first, second, third, fourth and fifth information signals is divided into a predetermined number of fuzzy labels of membership function to derive a parameter for operation of the air conditioning unit.