US 8,078,377 B2Granted

Compressed air supply system and method for determining system parameters

AssigneeWABCO GmbH

InventorsHeinrich Diekmeyer, Joachim Reinhardt, Andreas Schäl, Christoph Wilken

Life of this patent

Estimating the term…

Loading patent…

Abstract

A vehicle compressed air supply system includes a supply part with compressor, an air drying part and a consumer part including consumer circuits with brake circuits supplied with compressed air via a multi-circuit safety valve. The brake circuits, and optionally at least one other consumer circuit, include compressed air tanks. Pressure in the circuits is monitored by sensors and evaluated by an electronic control device. To determine system parameters in terms of tank size and compressor output, when filling circuits, the rate of pressure increase in a circuit is determined as a function of compressor speed, and air-drying regeneration is effected. The period of a pre-defined pressure drop or pre-defined pressure gradient is determined and air volume for completing regeneration is calculated from the magnitude of the pressure drop, regeneration time and throttle diameter. Tank volume is determined therefrom. Compressor output is calculated from tank volume and rate of pressure increase.

Claims30

Dependent claims

A compressed air supply system for a motor vehicle, comprising:

a compressed air supply part including a compressor;
an air dryer part including an air dryer cartridge, a throttle and a valve;
a compressed air consuming part including compressed air consuming circuits including service brake circuits, at least said service brake circuits including compressed air tanks;
a multi-circuit protective valve operable to supply said compressed air consuming circuits with compressed air;
sensors operable to monitor pressure in said compressed air consuming circuits;
and
an electronic control device operable to receive and evaluate electrical signals from said sensors, said electronic control device being suitably programmed to adaptively optimize operation of said air dryer part based on compressed air tank volume and compressor output capacity by:
determining the rate of increase in air pressure in at least one of said compressed air consuming circuits as a function of compressor speed during filling of said at least one of said compressed air consuming circuits, regenerating said air dryer cartridge from said at least one of said compressed air consuming circuits when said at least one of said compressed air consuming circuits is filled with compressed air, determining one of (i) the time for a pre-defined pressure drop and (ii) the pressure drop over a pre-defined time calculating the amount of air for regeneration from (a) the magnitude of said pressure drop, (b) regeneration time and (c) diameter of said throttle, calculating tank volume of a compressed air tank of said at least one of said compressed air consuming circuits, and calculating said compressor output capacity from said tank volume and at least one of said rate of increase in air pressure and filling time.

5 more elements

A method for determining the parameters of a compressed air supply system for a motor vehicle, said compressed air supply system including a compressed air supply part having a compressor, an air dryer part including an air dryer cartridge, an orifice and a valve, a compressed air consuming part having compressed air consuming circuits including service brake circuits, at least said service brake circuits including compressed air tanks, a multi-circuit protective valve operable to supply said compressed air consuming circuits with compressed air, sensors operable to monitor pressure in said compressed air consuming circuits, and electronic control device operable to evaluate electrical signals from said sensors, the method comprising the steps of:

filling said compressed air consuming circuits,
determining the rate of increase of air pressure in at least one of said compressed air consuming circuits as a function of compressor speed,
when said at least one of said compressed air consuming circuits is filled, regenerating said air dryer cartridge with compressed air from said at least one of said compressed air consuming circuits,
determining one of (i) the time of a pre-defined pressure drop and (ii) the pressure drop over a pre-defined time,
determining the amount of air for regeneration from the magnitude of said pressure drop, regeneration time and diameter of said orifice,
determining tank volume of a compressed air tank of said at least one of said compressed air consuming circuits,
calculating output capacity of said compressor from said tank volume and at least one of said rate of increase of air pressure and filling time, and
adaptively optimizing operation of said air dryer part based on said compressed air tank volume and said compressor output capacity.

5 more elements

Dependencies are inferred from the claim text.