Abstract: Disclosed is an air conditioner for automobiles comprising an air conditioning unit for adjusting at least temperature of blow-off air discharged into a vehicle compartment, a decision device for determining whether the air conditioning unit is in an initial state that the air conditioning unit is started, and an air conditioning control unit for feedback controlling the air conditioning unit so that the detected internal temperature becomes equal to the set target temperature. The air conditioning control unit is formed as an integral-added optimal regulator which performs the feedback control on the basis of optimal feedback gain predetermined in accordance with a dynamic model of an air conditioning system. The air conditioning control unit outputs to the air conditioning unit controlled variables decided in accordance with the results of the determination made by the decision device.

Abstract: In an air conditioner for automobiles, control unit for performing feedback control of blow off air is constructed in the form of an integral-added optimal regulator (M4) which performs the feedback control on the basis of optimal feedback gain predetermined according to dynamic model(s) of an air conditioning system including the vehicle compartment (M1) and the used air conditioning unit (M2). According to another feature of the present invention, an environmental condition, such as solar radiation to the vehicle compartment (M1), is detected to further accurately control the internal air temperature. In one embodiment, the internal variables including optimal feedback gain of the integral-added optimal regulator (M4) are changed in accordance with the variation in the dynamic model depending on the detected environmental condition.