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

Abstract

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.

Description

[0001] Cross References to Related Applications [0002] This application claims priority from the patent application in Germany with application number 102011103211.1 entitled "Anti-sound system for an exhaust system and control method therefor", the content of which is hereby incorporated by reference in its entirety . technical field [0003] The present invention relates to an active noise control system for an exhaust system and a control method thereof. Accordingly, the present invention relates to at least one of active cancellation, reduction and modification of sound waves in the exhaust system of an internal combustion engine driven vehicle. Background technique [0004] Irrespective of the design of internal combustion engines (e.g. reciprocating engines, pistonless rotary engines or free-piston engines), due to the continuously occurring working cycles (in particular intake and compression of fuel-air mixture, ignition / expansion and discharge of combusted fuel-a...

AI Technical Summary

Problems solved by technology

Silencers / mufflers constructed according to any of these principles have the disadvantage that they require a relatively large volume and impose a relatively high resistance to the burning fuel-air mixture where high damping efficiency is required

[0015] In the case of known active noise control systems, the temperature-dependent compensation of the sound velocity between the loudspeaker and the error microphone is complicated, which is disadvantageous

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