Abstract: A method for operating a pneumatic system of a vehicle is disclosed. The pneumatic system comprises an electronically and/or pneumatically controlled compressor which supplies compressed air during a normal mode and which is switched off or idles when not supplying compressed air. In the method, an ambient temperature (T_Umg) around the pneumatic system is continuously sensed and compared with a predefined target temperature (T_Ziel), a freezing risk is detected when the ambient temperature (T_Umg) reaches or drops below the target temperature (T_Ziel), and when a freezing risk has been detected, a cold mode is activated in which the compressor delivers compressed air also outside delivery phases of the normal mode, and additional compressed air is supplied to pneumatic system components that risk freezing. An additional ON time (ED_zus) of the compressor in the cold mode is variably controlled.

Abstract: A method for operating a pneumatic system of a vehicle is disclosed. The pneumatic system comprises an electronically and/or pneumatically controlled compressor which supplies compressed air during a normal mode and which is switched off or idles when not supplying compressed air. In the method, an ambient temperature (T_Umg) around the pneumatic system is continuously sensed and compared with a predefined target temperature (T_Ziel), a freezing risk is detected when the ambient temperature (T_Umg) reaches or drops below the target temperature (T_Ziel), and when a freezing risk has been detected, a cold mode is activated in which the compressor delivers compressed air also outside delivery phases of the normal mode, and additional compressed air is supplied to pneumatic system components that risk freezing. An additional ON time (ED_zus) of the compressor in the cold mode is variably controlled.

Abstract: A compressed air supply system for motor vehicles includes a compressor, control electronics, an air dryer having an inlet channel for non-dried compressed air, an outlet channel for the dried compressed air, and a dehumidification device through which the compressed air to be dried can flow, a pressure regulator having an outlet valve for controlling the compressor between an idle phase and a load phase, a multi-circuit safety valve that is connected to the outlet channel of the air dryer via a compressed air line, and over-flow valves for the individual circuits, a regeneration valve and a moisture sensor for detecting the atmospheric moisture in the compressed air flowing in the compressed air line. To reduce the detrimental effects of admixtures and components of the compressed air on the moisture sensor, the moisture sensor is located in a bypass channel of the compressed air line.

Abstract: An electronic compressed air system for vehicles includes a compressed air supply part having a compressor, a compressed air consumer part having load circuits forming an air-suspension circuit, and service-brake circuits having reservoirs. The load circuits are supplied with compressed air via solenoid valves. The pressure in the load circuits is monitored by pressure sensors whose signals are evaluated by an ECU that controls the solenoid valves. The solenoid valve of the air-suspension circuit does not include reservoirs and is closed in the de-energized normal state. The solenoid valves of other load circuits, especially of the service-brake circuits are open in the de-energized normal state. With a pressure demand of the air-suspension circuit, the associated solenoid valve is switched by the ECU to open position to establish communication with the compressed air supply part and/or with the service-brake circuits or with the reservoirs thereof, to refill the air-suspension circuit.

Abstract: To detect a defect or failure of a compressed air load circuit in a compressed air system for vehicles, pressure is measured in compressed air load circuits and evaluated in an electronic control unit, which briefly shuts off the compressed air load circuits, measures pressure values and/or determines pressure gradients during the shutoff time and compares the pressure values and/or the determined pressure gradients with a respective threshold value, identifies defective circuits and definitively shuts off circuits detected as defective if the results are below the threshold value.

Abstract: To detect a failure of a compressed air consumer circuit in a compressed air system for vehicles, pressure is continuously measured in compressed air consumer circuits and evaluated in an electronic control unit which compares the pressure values and/or determined negative pressure gradients of the compressed air consumer circuits with a respective threshold value and shuts off an air-consumer circuit if the pressure values and/or negative pressure gradients thereof satisfy a circuit-failure criterion. The circuit-failure criterion is satisfied when the pressure values and/or pressure gradients are below the respective threshold value for a time equal to or longer than the time of a dynamic pressure change or of a dynamic pressure collapse.

Abstract: A method and system is provided for refilling vehicle operational brake circuits after a large consumption of compressed air. The operational brake circuits are compressed air consumer circuits of a consumer part of a vehicle compressed air system. The operational brake circuits also include at least one additional compressed air consumer circuit provided with a compressed air reservoir. The actual pressure values in the operational brake circuits and in the additional compressed air consumer circuit are continuously determined and compared against a lower threshold value. If the values are below the threshold value, the identified operational brake circuits are blocked as defective and communication is established between the additional compressed air consumer circuits and the intact operational brake circuits in order to refill the operational brake circuits from the compressed air reservoirs of the additional compressed air consumer circuits.

Abstract: A compressed air supply system for motor vehicles includes a compressor, control electronics, an air dryer having an inlet channel for non-dried compressed air, an outlet channel for the dried compressed air, and a dehumidification device through which the compressed air to be dried can flow, a pressure regulator having an outlet valve for controlling the compressor between an idle phase and a load phase, a multi-circuit safety valve that is connected to the outlet channel of the air dryer via a compressed air line, and over-flow valves for the individual circuits, a regeneration valve and a moisture sensor for detecting the atmospheric moisture in the compressed air flowing in the compressed air line. To reduce the detrimental effects of admixtures and components of the compressed air on the moisture sensor, the moisture sensor is located in a bypass channel of the compressed air line.

Abstract: To detect a failure of a compressed air consumer circuit in a compressed air system for vehicles, pressure is continuously measured in compressed air consumer circuits and evaluated in an electronic control unit which compares the pressure values and/or determined negative pressure gradients of the compressed air consumer circuits with a respective threshold value and shuts off an air-consumer circuit if the pressure values and/or negative pressure gradients thereof satisfy a circuit-failure criterion. The circuit-failure criterion is satisfied when the pressure values and/or pressure gradients are below the respective threshold value for a time equal to or longer than the time of a dynamic pressure change or of a dynamic pressure collapse.

Abstract: A method and system is provided for refilling vehicle operational brake circuits after large consumption of compressed air. The operational brake circuits are compressed air consumer circuits of a consumer part of a vehicle compressed air system. The operational brake circuits also includes at least one additional compressed air consumer circuit provided with a compressed air reservoir. The actual pressure values in the operational brake circuits and in the additional compressed air consumer circuits are continuously determined and compared against a lower threshold value. If the values are below the threshold value, the identified operational brake circuits are blocked as defective and communication is established between the additional compressed air consumer circuits and the intact operational brake circuits in order to refill the operational brake circuits from the compressed air reservoirs of the additional compressed air consumer circuits.

Abstract: To detect a defect or failure of a compressed air load circuit in a compressed air system for vehicles, pressure is measured in compressed air load circuits and evaluated in an electronic control unit, which briefly shuts off the compressed air load circuits, measures pressure values and/or determines pressure gradients during the shutoff time and compares the pressure values and/or the determined pressure gradients with a respective threshold value, identifies defective circuits and definitively shuts off circuits detected as defective if the results are below the threshold value.

Abstract: An electronic compressed air system for vehicles includes a compressed air supply part having a compressor, a compressed air consumer part having load circuits forming an air-suspension circuit, and service-brake circuits having reservoirs. The load circuits are supplied with compressed air via solenoid valves. The pressure in the load circuits is monitored by pressure sensors whose signals are evaluated by an ECU that controls the solenoid valves. The solenoid valve of the air-suspension circuit does not include reservoirs and is closed in the de-energized normal state. The solenoid valves of other load circuits, especially of the service-brake circuits are open in the de-energized normal state. With a pressure demand of the air-suspension circuit, the associated solenoid valve is switched by the ECU to open position to establish communication with the compressed air supply part and/or with the service-brake circuits or with the reservoirs thereof, to refill the air-suspension circuit.