Gm Global Technolgoy Operations, Inc.

Delphi Technologies, Inc.

Giles M Brandon

Charles Andrew Archibald

Christopher M Kachur

Ernesto Jose Gutierrez

Francois M Bancon

Vincent M Braunschweig

Jean Marie L'Huillier

Ronald J Goubeaux

In a method for the diagnosis of an air conditioning system having a condenser, an evaporator, an expansion device and a compressor, the stroke of which can be set via a valve, a maximum compressor stroke is set abruptly when the air conditioning system is running and a pressure impulse arising in the high pressure side of the refrigerant circuit is measured in order to determine the degree of filling of the refrigerant circuit.

Method for the diagnosis of an air conditioning system

In a method for the control of the switching on behavior of an air conditioning system having a condenser, an evaporator, an expansion device and a compressor, the stroke of which can be set via a valve, the compressor is driven by a drive via a clutch. The imminent or already accomplished engagement of the clutch is detected as an event by an electronic control system of the air conditioning system. In the method the valve for the control of the stroke of the compressor is actuated in dependence on the event by the control system in order to minimize the torque fluctuations transmitted to the drive.

Method for the control of the switching on and off behavior of an air

In a method for the temperature regulation of an air conditioning system having a condenser, an evaporator, an expansion device and a compressor, the stroke of which can be set via a valve, the temperature in the region of the air outlet of the evaporator is measured and a desired temperature is set by a controlling of the valve. The temperature regulation additionally takes place in dependence on the refrigerant pressure.

Method for regulating the cooling performance of an air conditioning

An improved control method for an electronically controlled variable displacement refrigerant compressor, where the control has normal and high speed displacement control modes, with smooth transitions between such control modes. The displacement control mechanism is in the form of a solenoid valve, and the valve is pulse-width-modulated (PWM) at a variable duty cycle to regulate displacement of the compressor. When the compressor is operating in a normal speed range, a first control mode determines a normal PWM duty cycle to satisfy cooling demand; when the compressor is operating in a high speed range, a second control mode determines an alternate PWM duty cycle based on compressor speed. The solenoid valve is operated in accordance with the duty cycle corresponding to the lower displacement. A smooth transition from the normal control mode to the high speed control mode is achieved by scheduling the alternate duty cycle as a function of compressor speed. Once in the high speed control mode, the parameters of the first control mode are adjusted so that the normal duty cycle matches the alternate duty cycle. This ensures a smooth transition from the high speed control mode to the normal control mode when the compressor speed falls back into the normal speed range.

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Bascharage, Luxembourg

Giles M Brandon