Abstract: A refrigeration cycle or an air conditioner including a refrigeration cycle is subjected to feedback control based on modern control theory. An apparatus controlling a controlled object, that is, the refrigeration cycle of the air conditioner including the refrigeration cycle, is formed as an optimal regulator. A controlled input to the controlled object includes a capacity of a compressor or a degree of opening of an expansion valve. A control output from the controlled object includes a temperature of air at a point downstream of the evaporator or a superheat of refrigerant. Feedback gains are predetermined by use of dynamic models constructed for respective steady operation states of the controlled object.

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.

Abstract: A case for accommodating an electronic circuit for an electronic control system mounted on a vehicle is formed of an electric conductor and is electrically isolated from the grounding terminal of the electronic circuit which is provided on a printed substrate. Further, the outer boundary of a signal line for signal transmission between the electronic circuit and external circuits or sensors of the case is connected to the case through capacitors, thus preventing the faulty actuation of the electronic control system which otherwise might be caused by the electromagnetic wave.

Abstract: An engine crank angle determining arrangement including a rotor having teeth or slits wherein either a tooth is entirely omitted or the teeth or slits are formed with non-uniform intervals therebetween. The teeth or slits are detected by an electromagnetic pick-up device or a photocoupler, and the time intervals corresponding to the intervals between the teeth or slits in the signal thus detected are processed in accordance with a predetermined program. The time intervals thus processed are corrected in consideration of an engine low state or non-low state operating condition, such as for example transient condition or starting condition, of the engine. Processing is carried out in either of two different ways of calculating reference angles.