Eberspächer Exhaust Technology Gmbh & Co. Kg

Eberspächer Unna Gmbh & Co. Kg

Christof Luecking

Bernd Maurer

Manfred Nicolai

Georg Huethwohl

Armin Kassel

Andre Mengel

Uwe Schumacher

Sebastian Pietrzyba

Frank Noack

The invention relates to a system for generating anti-noise in an exhaust-gas line () of a vehicle, comprising a first electro acoustic transducer () for generating a first acoustic signal based on an electric control signal, and being in communication with the exhaust-gas line via an acoustic line (), with the first acoustic signal entering the exhaust line in form of anti-noise after having passed the acoustic line, a second electro acoustic transducer () for generating an electric measurement signal representing a second acoustic signal, and being in acoustic communication with the exhaust-gas line () at the anti-noise coupling region, a control unit () for generating the control signal based on the measurement signal, and a parameterizing unit () for determining a conforming phase parameter and a conforming magnitude parameter for the control function used by the control unit () based on the transient response of the control unit.

Transmission path compensator

A method for controlling an anti-sound system includes measuring sound within an exhaust system of a vehicle, calculating a control signal based on the measured sound, calculating a thermal load to be expected of the at least one loudspeaker of the anti-sound system during operation with a control signal based on a mathematical model of a thermal behavior of the loudspeaker and/or a mechanical load to be expected of the at least one loudspeaker of the anti-sound system based on a mathematical model of a mechanical behavior the loudspeaker, comparing the calculated thermal and/or mechanical load with a specified maximum load, operating the loudspeaker with the control signal, if the calculated thermal and/or mechanical load is smaller than or equal to the maximum load, and changing the spectrum of the control signal, in order to receive a corrected control signal, if the calculated load is greater than the maximum load.

Overload protection for loudspeakers in exhaust systems

An active noise control system for exhaust systems of a combustion engine operated vehicle comprises an anti-sound control connectable to an engine control of the vehicle and a loudspeaker connected to the control for receiving control signals and designed for generating an anti-sound in a sound generator, fluidically connectable to the exhaust system. In the control, at least two curves are stored in order to cancel airborne sound conducted in the exhaust system through outputting the signal to the loudspeaker. The curves cover different temperature ranges of the exhaust gas, which temperature ranges overlap one another by pairs or directly adjoin one another. The control is furthermore designed to select a curve suitable for a respective temperature of the exhaust gas conducted in the exhaust system from the available curves by means of signals output by the engine control and output signals to the loudspeaker making use of this curve.

Active noise control system for exhaust systems and method for controlling the same

Based on sound measured in the interior of an exhaust system components of an ideal control signal are calculated, the components comprising sine wave oscillations comprising amplitudes phase-shifted by 90&#xb0; relative to each other. From the amplitudes, an overall amplitude is calculated. If the overall amplitude is greater than a reference amplitude, calculating a correction factor from the reference amplitude and the overall amplitude, weighting the amplitudes with the correction factor to obtain weighted amplitudes, and forming the sum of the products of the weighted amplitudes with the associated sine wave oscillations and outputting the sum as control signal to a loudspeaker, follows. Otherwise, if the overall amplitude is smaller or equal to the reference amplitude, forming the sum of the products of the amplitudes of the ideal control signal with the associated sine wave oscillations and outputting the sum as control signal to the loudspeaker, follows.

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Wetter, Germany

Christof Luecking