EP1534939A1 - Active vent noise reduction device for use with an exhaust or intake pipe - Google Patents

Active vent noise reduction device for use with an exhaust or intake pipe

Info

Publication number
EP1534939A1
EP1534939A1 EP03753666A EP03753666A EP1534939A1 EP 1534939 A1 EP1534939 A1 EP 1534939A1 EP 03753666 A EP03753666 A EP 03753666A EP 03753666 A EP03753666 A EP 03753666A EP 1534939 A1 EP1534939 A1 EP 1534939A1
Authority
EP
European Patent Office
Prior art keywords
sensors
noise
duct
exhaust
conduit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03753666A
Other languages
German (de)
French (fr)
Inventor
Alain Haupais
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Comptoir de la Technologie
Original Assignee
Comptoir de la Technologie
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Comptoir de la Technologie filed Critical Comptoir de la Technologie
Publication of EP1534939A1 publication Critical patent/EP1534939A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/12—Intake silencers ; Sound modulation, transmission or amplification
    • F02M35/1244—Intake silencers ; Sound modulation, transmission or amplification using interference; Masking or reflecting sound
    • F02M35/125—Intake silencers ; Sound modulation, transmission or amplification using interference; Masking or reflecting sound by using active elements, e.g. speakers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/06—Silencing apparatus characterised by method of silencing by using interference effect
    • F01N1/065—Silencing apparatus characterised by method of silencing by using interference effect by using an active noise source, e.g. speakers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/10373—Sensors for intake systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/0027—Pulsation and noise damping means
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17857—Geometric disposition, e.g. placement of microphones
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1787—General system configurations
    • G10K11/17879—General system configurations using both a reference signal and an error signal
    • G10K11/17881—General system configurations using both a reference signal and an error signal the reference signal being an acoustic signal, e.g. recorded with a microphone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2230/00—Combination of silencers and other devices
    • F01N2230/02—Exhaust filters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices

Definitions

  • the invention relates to the field of reduction of acoustic emissions.
  • the invention aims to reduce the mouth noises generated by pulsed flows such as for example the exhaust or the intake of an alternating engine, or even the intake of an alternating compressor. It finds a very particular application on vehicles with thermal engine, and in particular motor vehicles, utility vehicles as well as stationary vehicles.
  • mouth noises generated by the flow of exhaust gases are one of the main sources of noise pollution from a vehicle equipped with an internal combustion engine.
  • the other sources of noise pollution reside in the noise of the mechanical parts within the engine itself, the combustion noise, the aerodynamic noise, the rolling noise, etc.
  • the mouth noises generated by the exhaust gases or the intake air can be analyzed as a sound wave propagating from the end of the duct.
  • this type of device has limitations in its proper operation when the exhaust duct is equipped with devices such as a particle filter, generating high pressure drops, and in particular a variable pressure drop.
  • a particle filter the principle of which consists in accumulating the particles entrained by the exhaust gases, within the exhaust duct.
  • the pressure drops it generates are variable, and typically in a ratio of 1 to 4 or more.
  • a problem which the invention proposes to solve is that of allowing an effective reduction of the mouth noise, despite the use of a particulate filter whose influence on the characteristics of the exhaust flow is by variable principle.
  • Another problem which the invention proposes to solve is that of providing a robust system which is not subjected to the influences of the temperature of the exhaust gases as well as the temperature variation.
  • Another problem that the invention seeks to solve is that of providing a counter-noise wave which is always as strictly as possible opposite to the noise emitted by the mouth, despite the variation in clogging of a particle filter.
  • the invention therefore relates to a device for attenuating the mouth noise generated at the end of an exhaust or intake pipe connected to a pulsed flow source, such as a heat engine, or a alternative compressor for example.
  • a pulsed flow source such as a heat engine, or a alternative compressor for example.
  • this device is characterized in that it comprises: at least two sensors arranged inside the duct, between the mouth of the duct and the pulsed flow source, and offset spatially with respect to the others, electronic means for processing the signals from said sensors, capable of generating signals corresponding to a counter-noise wave, at least one electro-acoustic source, placed in close proximity to the mouth of the duct, and controlled by the corresponding signals of the counter-noise wave.
  • the device according to the invention ensures the capture of the pressure wave which propagates along the exhaust duct by means of several spatially offset sensors, which makes it possible to determine not only the shape, and the amplitude, but also the moment when this pressure wave will appear at the mouth, by analyzing the difference between the signals from different sensors.
  • these sensors are placed sufficiently upstream of the end of the conduit, and therefore of the counter-noise source to allow a precise and faithful development of the counter-noise wave by compensating for the response times of the source.
  • Electroacoustic Electroacoustic.
  • the electro-acoustic source is disposed not inside the exhaust pipe but outside of the latter, which means that it is not subjected to the high temperatures of the exhaust gases, and to the contact with potentially corrosive substances.
  • This electro-acoustic source is arranged in such a way that the counter-noise wave which it emits comes from a point which is very close to the point of emission of the muzzle wave, so that the strict opposition of phase between noise and against noise obtained at the mouth is preserved in all the space where these two waves propagate.
  • the conduit when the conduit is equipped with a cavity acting as a silencer, or in particular as a particle filter, the sensors are arranged between this cavity and the end of the conduit. In this way, it eliminates disturbances that can affect the pressure wave when it propagates inside this type of cavity.
  • the device can also include an additional sensor, disposed near the end of the duct, and connected to the processing means.
  • an additional sensor disposed near the end of the duct, and connected to the processing means.
  • Such a sensor makes it possible to observe, outside of the conduit and at a point representative of the external volume to be protected, the correction errors, so as to consequently correct the parameters which intervene in the algorithm for calculating the control signals of the counter-noise sources.
  • Such a sensor makes it possible in particular to adapt this algorithm with respect to slowly varying external parameters, such as temperature or atmospheric pressure.
  • the sensors In practice, it is considered that it is preferable for the sensors to be distant from the end of the conduit by a distance of the order of one meter. This distance, for frequencies of the order of kiloHertz, allows sufficient processing time with conventional electronic means of the microprocessor type for signal processing (DSP).
  • DSP signal processing
  • the sensors are distant from each other by a distance of the order of a decimeter, which makes it possible to discriminate without difficulty the phase of the pressure wave for a range of frequencies up to kiloHertz approx.
  • the electro-acoustic sources can be arranged in an annular ring, concentric with the end of the duct, so that the counter-noise wave is emitted from a centered area on the axis of the duct. Maintaining the strict opposition between the noise wave and the counter-noise wave during the propagation of the latter at any distance from the mouth is therefore favored.
  • Figure 1 is a diagram illustrating the arrangement of the different organs of the device according to the invention, fitted to an exhaust duct.
  • Figure 2 is a schematic representation of a device according to the invention applied to an intake duct.
  • the invention relates to a device for attenuating noise nuisance caused by mouth noises from an exhaust pipe, in particular from a motor vehicle.
  • the application to such an exhaust circuit is illustrated in FIG. 1.
  • the active device (1) object of the present invention is placed at the outlet of the exhaust line (3) itself located at the outlet of the engine ( 2).
  • the exhaust line (3) comprises various pipes (4,7) making it possible to channel the exhaust gases (5) to an assembly composed for example of a silencer (6) and a particle filter ( 8) arranged to retain a fraction of the solid particles entrained by the exhaust gases (5).
  • the present invention also covers the application of the active attenuation device described to exhaust lines of all types, comprising a simple silencer, or an expansion volume connected to a silencer by a tube, or even a filter. anti-particles used alone, additional volumes, whatever the arrangement of these components.
  • the attenuation device (1) comprises at least two sensors (15,16) arranged on the tube (9), directly downstream of the exhaust line (3).
  • These pressure sensors can be of the capacitive or inductive diaphragm microphone type, piezoelectric microphone or any other type.
  • These two sensors (15) (16) generate electrical signals representative of the pressure wave propagating in the conduit (9). 4 0
  • These electrical signals are routed to a computer (17) equipped with processing and calculation means, which may in particular include signal processing processors (DSP).
  • processing and calculation means which may in particular include signal processing processors (DSP).
  • DSP signal processing processors
  • processing means (17) are programmed to determine the amplitude of the wave which will appear at the mouth and the instant when it will appear there, from each signal produced by the sensors (15,16), taking into account the distance (d) separating the two sensors along the gas propagation path.
  • This calculation is based on the determination of the propagation speed of this wave from the phase shift between the signals from the sensors (15) and (16). It can separate the incident waves propagating from the sensors towards the mouth from the reflected waves propagating from the mouth towards the sensors.
  • This development can take into account different parameters and in particular the shape of the conduit downstream of the sensors (15,16) and the corresponding pressure drops. Other parameters such as temperature or the like can also be taken into account.
  • the processing means (17) develop a counter-noise signal corresponding to the wave which combined with the mouth wave is intended to reduce the sound intensity emitted by being as strictly as possible opposed to it.
  • the processing means (17) control with the time offset necessary to compensate for the response times of the electroacoustic sources (20,21) located nearby. from the end (10) of the conduit (9).
  • These electro-acoustic sources can be of very varied types and in particular be formed by loudspeakers, compression chambers, or others.
  • the processing means are also programmed to take account of the times of rise of these different electro-acoustic sources, corresponding to the offset between the emission of a sound wave by the electro-acoustic source relative to the electrical control signal.
  • the electro-acoustic sources (20, 21) are arranged at the periphery of an annular ferrule (22) arranged concentrically with the conduit (9).
  • the center of symmetry of this ferrule (22) therefore corresponds to the center of the end (10) of the duct (9), so that the virtual point corresponding to the center of emission of the counter-noise wave is coincident with the emission point of the mouth wave.
  • the annular ferrule (22) is equipped with two electro-acoustic sources (20) (21) which open out inside the ferrule (22).
  • the electro-acoustic sources of counter-noise can be arranged not in a concentric ferrule (22), but have one or more outlet chambers oriented parallel to the outlet of the conduit (9).
  • the electro-acoustic sources of counter-noise can also be placed near the outlet (10) by fixing them to any suitable support.
  • an additional sensor (25) is arranged near the end (10) of the duct in an area where the muzzle wave and the counter-noise wave combine.
  • This sensor (25) is connected to the processing means (17), which makes it possible to carry out a feedback making it possible to correct certain processing errors.
  • these correction errors make it possible to modify certain parameters of the algorithm for calculating the control signals of the counter-noise sources which vary slowly over time, such as in particular the outside temperature or the atmospheric pressure.
  • the sensors (15, 16) are distant from the sources of counter-noise by a distance (D) of the order of a meter, which allows a time shift of a few milliseconds from the capture, for the development of the counter-noise signal and control of the electro-acoustic source, taking into account its rise time.
  • the invention is also suitable for the treatment of muzzle waves generated in an intake duct and this as illustrated in FIG. 2.
  • the muzzle wave has been brought to the level of the end (30) of inlet of the conduit (39).
  • Two sensors (35,36) are arranged upstream of the air filter (38).
  • the processing means (37) perform the same type of calculation for the development of the counter-noise wave which will be emitted by the electroacoustic sources (40) (42).
  • the device according to the invention has multiple advantages and in particular that of estimating with anticipation the noise which will be emitted by the mouth of the conduit, so as to be able to carry out the corrections necessary to predetermine the signal of control of the noise canceling transmitter.
  • the pressure sensors are not subjected to high average pressures if the particle filter or the air filter are clogged.
  • the more or less complex transfer functions of the silencers, and variable when a filter is used, are not to be taken into account in the signal processing algorithm.

Abstract

The invention relates to a device for reducing the vent noise generated at an exhaust (9) or intake (39) pipe which is connected to a pulsed flow source (2) such as a heat engine (2) or a reciprocating compressor. The invention is characterised in that it comprises at least two sensors (15, 16) which are disposed inside the pipe (9) between the end (10) of the pipe (9) and the pulsed flow source (2) and which are shifted spatially in relation to one another, electronic means (17) of processing the signals from said sensors (15, 16) which can generate signals corresponding to a counternoise wave, and at least one electro-acoustic source (20, 21) which is disposed outside the pipe (9) but in direct proximity to the end (10) thereof and which is controlled by the signals corresponding to the counternoise wave.

Description

DISPOSITIF ACTIF D'ATTENUATION DU BRUIT DE BOUCHE AU NIVEAU D'UN CONDUIT D'ECHAPPEMENT OU D'ADMISSIONACTIVE DEVICE FOR ATTENUATING MOUTH NOISE AT AN EXHAUST OR INTAKE DUCT
Domaine technique : L'invention se rattache au domaine de la réduction des émissions acoustiques. L'invention vise à réduire les bruits de bouche générés par des écoulements puisés tels que par exemple l'échappement ou l'admission d'un moteur alternatif, ou bien encore l'admission d'un compresseur alternatif. Elle trouve une application toute particulière sur les véhicules à moteur thermique, et notamment les véhicules automobiles, utilitaires ainsi que les engins stationnaires.Technical field: The invention relates to the field of reduction of acoustic emissions. The invention aims to reduce the mouth noises generated by pulsed flows such as for example the exhaust or the intake of an alternating engine, or even the intake of an alternating compressor. It finds a very particular application on vehicles with thermal engine, and in particular motor vehicles, utility vehicles as well as stationary vehicles.
Technique antérieure :Prior art:
De façon générale, il est reconnu que les bruits de bouche générés par l'écoulement des gaz d'échappement sont une des principales sources de nuisances sonores d'un véhicule équipé d'un moteur à explosion. Les autres sources de nuisances sonores résident dans le bruit des pièces mécaniques au sein du moteur lui-même, le bruit de combustion, le bruit aérodynamique, le bruit de roulement, etc.. . Plus précisément, les bruits de bouche générés par les gaz d'échappement ou l'air admis peuvent s'analyser en une onde sonore se propageant à partir de l'extrémité du conduit.In general, it is recognized that mouth noises generated by the flow of exhaust gases are one of the main sources of noise pollution from a vehicle equipped with an internal combustion engine. The other sources of noise pollution reside in the noise of the mechanical parts within the engine itself, the combustion noise, the aerodynamic noise, the rolling noise, etc. More specifically, the mouth noises generated by the exhaust gases or the intake air can be analyzed as a sound wave propagating from the end of the duct.
Différentes solutions ont été proposées pour réduire l'intensité sonore générée par ces bruits de bouche. Dans une première approche, il a été proposé d'équiper le conduit d'échappement d'un papillon mobile, dont le déplacement est commandé pour faire varier les pertes de charge du conduit d'échappement. Cette variation instantanée de pertes de charge du conduit est commandée selon un signal élaboré à partir d'un capteur mesurant la variation de pression à l'entrée du conduit d'échappement, de façon à minimiser les fluctuations de débit et de pression en sortie de la ligne, responsables du bruit émis par la bouche. Un tel dispositif présente certains inconvénients, notamment en ce qui concerne la motorisation nécessaire pour assurer le déplacement du papillon, car elle exige des temps de réponse suffisamment courts. En outre, le papillon s'opposant au flux d'échappement doit présenter une rigidité suffisante qui se traduit généralement par une augmentation de sa masse et donc une plus grande difficulté à en commander le déplacement.Different solutions have been proposed to reduce the loudness generated by these mouth sounds. In a first approach, it has been proposed to equip the exhaust duct with a movable throttle, the displacement of which is controlled to vary the pressure losses of the exhaust duct. This instantaneous variation in pressure drops in the duct is controlled according to a signal produced from a sensor measuring the pressure variation at the inlet of the exhaust duct, so as to minimize the fluctuations in flow rate and pressure at the outlet of the line, responsible for the noise emitted by the mouth. Such a device has certain drawbacks, in particular as regards the motorization necessary to ensure the displacement of the butterfly, since it requires sufficiently short response times. In addition, the throttle opposing the exhaust flow must have sufficient rigidity which generally results in an increase in its mass and therefore greater difficulty in controlling its displacement.
Par ailleurs, ce type de dispositif présente des limitations dans son bon fonctionnement lorsque le conduit d'échappement est équipé de dispositifs tels qu'un filtre à particules, générant de fortes pertes de charges, et notamment une perte de charge variable. En effet, et en particulier sur les véhicules à moteur diesel, les réglementations imposent de mettre en place des filtres à particules dont le principe consiste à accumuler les particules entraînées par les gaz d'échappement, au sein du conduit d'échappement. Au fur et à mesure de l'encrassement de ce filtre à particules, les pertes de charge qu'il génère, sont variables, et typiquement dans un rapport de 1 à 4 ou plus. Ces pertes de charge supplémentaires variables perturbent fortement la régulation des placements du déplacement du papillon à mettre en œuvre.Furthermore, this type of device has limitations in its proper operation when the exhaust duct is equipped with devices such as a particle filter, generating high pressure drops, and in particular a variable pressure drop. Indeed, and in particular on vehicles with a diesel engine, the regulations require the installation of particle filters, the principle of which consists in accumulating the particles entrained by the exhaust gases, within the exhaust duct. As the particle filter becomes clogged, the pressure drops it generates are variable, and typically in a ratio of 1 to 4 or more. These variable additional head losses greatly disturb the regulation of the placements of the movement of the butterfly to be implemented.
Dans une autre approche, il a été également proposé d'injecter une onde de contre-bruit au niveau du conduit d'échappement et typiquement au sein du dispositif de silencieux formant une cavité disposée sur le parcours des gaz d'échappement. Une telle solution est par exemple décrite dans le document WO-00/05489. La source de contre-bruit implantée dans le silencieux est commandée à partir d'un signal issu d'un capteur disposé en amont sur le conduit d'échappement. Un des inconvénients de ce type de dispositif réside, d'une part, dans le fait que la source de contre-bruit subit la pression moyenne qui règne dans le silencieux et qui peut atteindre des valeur élevées lorsqu'il s'agit du filtre à particules colmaté. D'autre part, la source de contre-bruit se trouve directement exposée aux températures très élevées produites par la régénération du filtre. Une autre inconvénient majeur réside dans le fait que le filtre à particules présente des caractéristiques acoustiques très variables en fonction de son état de colmatage. Ainsi, parmi les ondes mesurées par le capteur placé à son entrée, la part de celles qui se propagent vers la bouche de sortie et la part de celles qui sont réfléchies vers l'amont sont variables ce qui nécessite une évolution ad hoc de la stratégie de correction, faute de quoi le résultat obtenu est loin d'être optimal.In another approach, it has also been proposed to inject a noise reduction wave at the level of the exhaust duct and typically within the muffler device forming a cavity disposed on the path of the exhaust gases. Such a solution is for example described in document WO-00/05489. The counter-noise source located in the silencer is controlled from a signal from a sensor placed upstream on the exhaust duct. One of the drawbacks of this type of device lies, on the one hand, in the fact that the counter-noise source is subjected to the average pressure which prevails in the silencer and which can reach high values when it is the filter clogged particles. On the other hand, the source of counter-noise is directly exposed to the very high temperatures produced by the regeneration of the filter. Another major drawback lies in the fact that the particle filter has very variable acoustic characteristics depending on its clogging state. Thus, among the waves measured by the sensor placed at its input, the share of those which propagate towards the exit mouth and the share of those which are reflected upstream are variable which requires an ad hoc evolution of the correction strategy, failing which the result obtained is far from optimal .
Un problème que se propose de résoudre l'invention est celui de permettre une atténuation du bruit de bouche qui soit efficace, et ce malgré l'emploi d'un filtre à particules dont l'influence sur les caractéristiques du flux d'échappement est par principe variable.A problem which the invention proposes to solve is that of allowing an effective reduction of the mouth noise, despite the use of a particulate filter whose influence on the characteristics of the exhaust flow is by variable principle.
Un autre problème que se propose de résoudre l'invention est celui de fournir un système robuste qui ne subisse pas les influences de la température des gaz d'échappement ainsi que la variation de température.Another problem which the invention proposes to solve is that of providing a robust system which is not subjected to the influences of the temperature of the exhaust gases as well as the temperature variation.
Un autre problème que cherche à résoudre l'invention est celui de fournir une onde de contre-bruit qui soit toujours le plus strictement possible opposée au bruit émis par la bouche, malgré la variation de colmatage d'un filtre à particules.Another problem that the invention seeks to solve is that of providing a counter-noise wave which is always as strictly as possible opposite to the noise emitted by the mouth, despite the variation in clogging of a particle filter.
Exposé de l'invention :Statement of the invention:
L'invention concerne donc un dispositif d'atténuation du bruit de bouche généré au niveau de l'extrémité d'un conduit d'échappement ou d'admission relié à une source d'écoulement puisé, tel qu'un moteur thermique, ou un compresseur alternatif par exemple.The invention therefore relates to a device for attenuating the mouth noise generated at the end of an exhaust or intake pipe connected to a pulsed flow source, such as a heat engine, or a alternative compressor for example.
Conformément à l'invention, ce dispositif se caractérise en ce qu'il comporte : au moins deux capteurs disposés à l'intérieur du conduit, entre la bouche du conduit et la source d'écoulement puisé, et décalés spacialement les uns par rapport aux autres, des moyens électroniques de traitement des signaux issus desdits capteurs, aptes à générer des signaux correspondants à une onde de contre-bruit, au moins une source électro-acoustique, disposée à proximité directe de la bouche du conduit, et commandée par les signaux correspondants de l'onde de contre-bruit.According to the invention, this device is characterized in that it comprises: at least two sensors arranged inside the duct, between the mouth of the duct and the pulsed flow source, and offset spatially with respect to the others, electronic means for processing the signals from said sensors, capable of generating signals corresponding to a counter-noise wave, at least one electro-acoustic source, placed in close proximity to the mouth of the duct, and controlled by the corresponding signals of the counter-noise wave.
Autrement dit, le dispositif conforme à l'invention assure la captation de l'onde de pression qui se propage le long du conduit d'échappement par l'intermédiaire de plusieurs capteurs décalés spacialement, ce qui permet de déterminer non seulement la forme, et l'amplitude, mais également le moment où cette onde de pression se présentera à la bouche, en analysant le décalage entre les signaux issus de capteurs différents. En outre, ces capteurs sont placés suffisamment en amont de l'extrémité du conduit, et donc de la source de contre-bruit pour permettre une élaboration précise et fidèle de l'onde de contre-bruit en compensant les temps de réponse de la source électroacoustique. Enfin, la source électro-acoustique est disposée non pas l'intérieur du conduit d'échappement mais à l'extérieur de ce dernier, ce qui fait qu'elle n'est pas soumise aux fortes températures des gaz d'échappement, et au contact de substances éventuellement corrosives. Cette source électro-acoustique est disposée de telle manière que l'onde de contre-bruit qu'elle émet provient d'un point qui est très proche du point d'émission de l'onde de bouche, de façon que la stricte opposition de phase entre bruit et contre bruit obtenue à la bouche se conserve dans tout l'espace où ces deux ondes se propagent.In other words, the device according to the invention ensures the capture of the pressure wave which propagates along the exhaust duct by means of several spatially offset sensors, which makes it possible to determine not only the shape, and the amplitude, but also the moment when this pressure wave will appear at the mouth, by analyzing the difference between the signals from different sensors. In addition, these sensors are placed sufficiently upstream of the end of the conduit, and therefore of the counter-noise source to allow a precise and faithful development of the counter-noise wave by compensating for the response times of the source. Electroacoustic. Finally, the electro-acoustic source is disposed not inside the exhaust pipe but outside of the latter, which means that it is not subjected to the high temperatures of the exhaust gases, and to the contact with potentially corrosive substances. This electro-acoustic source is arranged in such a way that the counter-noise wave which it emits comes from a point which is very close to the point of emission of the muzzle wave, so that the strict opposition of phase between noise and against noise obtained at the mouth is preserved in all the space where these two waves propagate.
En pratique, lorsque le conduit est équipé d'une cavité jouant le rôle de silencieux, ou de filtre à particules notamment, les capteurs sont disposés entre cette cavité et l'extrémité du conduit. De la sorte, on s'affranchit des perturbations pouvant affecter l'onde de pression lorsqu'elle se propage à l'intérieur de ce type de cavité.In practice, when the conduit is equipped with a cavity acting as a silencer, or in particular as a particle filter, the sensors are arranged between this cavity and the end of the conduit. In this way, it eliminates disturbances that can affect the pressure wave when it propagates inside this type of cavity.
Dans une forme particulière de réalisation, le dispositif peut également comprendre un capteur additionnel, disposé à proximité de l'extrémité du conduit, et relié aux moyens de traitement. Un tel capteur permet de constater, à l'extérieur du conduit et en un point représentatif du volume extérieur à protéger, les erreurs de correction, de manière à corriger en conséquence les paramètres qui interviennent dans l'algorithme de calcul des signaux de commande des sources de contre-bruit. Un tel capteur permet notamment d'adapter cet algorithme vis à vis des paramètres extérieurs variant de façon lente, tels que la température, ou la pression atmosphérique.In a particular embodiment, the device can also include an additional sensor, disposed near the end of the duct, and connected to the processing means. Such a sensor makes it possible to observe, outside of the conduit and at a point representative of the external volume to be protected, the correction errors, so as to consequently correct the parameters which intervene in the algorithm for calculating the control signals of the counter-noise sources. Such a sensor makes it possible in particular to adapt this algorithm with respect to slowly varying external parameters, such as temperature or atmospheric pressure.
En pratique, on considère qu'il est préférable que les capteurs soient éloignés de l'extrémité du conduit d'une distance de l'ordre du mètre. Cette distance, pour les fréquences de l'ordre du kiloHertz permet un temps de traitement suffisant avec des moyens électroniques conventionnels du type microprocesseurs de traitement du signal (DSP).In practice, it is considered that it is preferable for the sensors to be distant from the end of the conduit by a distance of the order of one meter. This distance, for frequencies of the order of kiloHertz, allows sufficient processing time with conventional electronic means of the microprocessor type for signal processing (DSP).
En pratique également, on préfère que les capteurs soient éloignés les uns des autres d'une distance de l'ordre du décimètre, ce qui permet de discriminer sans difficultés la phase de l'onde de pression pour une gamme de fréquences allant jusqu'au kiloHertz environ.In practice also, it is preferred that the sensors are distant from each other by a distance of the order of a decimeter, which makes it possible to discriminate without difficulty the phase of the pressure wave for a range of frequencies up to kiloHertz approx.
Dans une forme particulière, particulièrement avantageuse de réalisation, les sources électro-acoustiques peuvent être disposées dans une virole annulaire, concentrique avec l'extrémité du conduit, de sorte que l'onde de contre-bruit est émise à partir d'une zone centrée sur l'axe du conduit. Le maintien de la stricte opposition entre l'onde de bruit et de l'onde de contre-bruit lors de la propagation de celles-ci à toute distance de la bouche en est donc favorisée.In a particular, particularly advantageous embodiment, the electro-acoustic sources can be arranged in an annular ring, concentric with the end of the duct, so that the counter-noise wave is emitted from a centered area on the axis of the duct. Maintaining the strict opposition between the noise wave and the counter-noise wave during the propagation of the latter at any distance from the mouth is therefore favored.
Toutefois, d'autres architectures peuvent être employées dans lesquelles les sources de contre-bruit sont simplement disposées à proximité de l'extrémité du conduit, de préférence, dans le cas ou elles sont multiples avec une répartition équilibrée autour du conduit. Description sommaire des figuresHowever, other architectures can be used in which the sources of counter-noise are simply placed near the end of the duct, preferably, in the case where they are multiple with a balanced distribution around the duct. Brief description of the figures
La manière de réaliser l'invention, ainsi que les avantages qui en découlent ressortiront bien de la description des modes d'exécution qui suivent, à l'appui des figures annexées dans lesquelles : - La figure 1 est un schéma illustrant la disposition des différents organes du dispositif conformément à l'invention, équipant un conduit d'échappement. La figure 2 est une représentation schématique d'un dispositif conformément à l'invention appliquée à un conduit d'admission.The manner of carrying out the invention, as well as the advantages which result from it, will emerge clearly from the description of the embodiments which follow, with the support of the appended figures in which: - Figure 1 is a diagram illustrating the arrangement of the different organs of the device according to the invention, fitted to an exhaust duct. Figure 2 is a schematic representation of a device according to the invention applied to an intake duct.
Manières de réaliser l'inventionWays to realize the invention
Comme évoqué, l'invention concerne un dispositif d'atténuation des nuisances sonores engendrées par les bruits de bouche d'un conduit d'échappement, de véhicule automobiles notamment. L'application à un tel circuit d'échappement est illustrée à la figure 1. Le dispositif actif (1) objet de la présente invention est placé en sortie de la ligne d'échappement (3) située elle-même en sortie du moteur (2). La ligne d'échappement (3) comprend différentes tubulures (4,7) permettant de canaliser les gaz d'échappement (5) jusqu'à un ensemble composé par exemple d'un silencieux (6) et d'un filtre à particules (8) agencé pour retenir une fraction des particules solides entraînées par les gaz d'échappement (5). Toutefois, la présente invention couvre également l'application du dispositif d'atténuation actif décrit à des lignes d'échappement de tous types, comprenant un simple silencieux, ou un volume de détente relié à un silencieux par une tubulure, ou bien encore un filtre anti-particules utilisé seul, des volumes additionnels, quel que soit l'agencement de ces composants.As mentioned, the invention relates to a device for attenuating noise nuisance caused by mouth noises from an exhaust pipe, in particular from a motor vehicle. The application to such an exhaust circuit is illustrated in FIG. 1. The active device (1) object of the present invention is placed at the outlet of the exhaust line (3) itself located at the outlet of the engine ( 2). The exhaust line (3) comprises various pipes (4,7) making it possible to channel the exhaust gases (5) to an assembly composed for example of a silencer (6) and a particle filter ( 8) arranged to retain a fraction of the solid particles entrained by the exhaust gases (5). However, the present invention also covers the application of the active attenuation device described to exhaust lines of all types, comprising a simple silencer, or an expansion volume connected to a silencer by a tube, or even a filter. anti-particles used alone, additional volumes, whatever the arrangement of these components.
Conformément à l'invention, le dispositif d'atténuation (1) comprend au moins deux capteurs (15,16) disposés sur la tubulure (9), directement en aval de la ligne d'échappement (3). Ces capteurs de pression, peuvent être du type microphone à membrane capacitif ou inductif, microphone piézoélectrique ou de tout autre type. Ces deux capteurs (15) (16) élaborent des signaux électriques représentatifs de l'onde de pression se propageant dans le conduit (9). 4 0According to the invention, the attenuation device (1) comprises at least two sensors (15,16) arranged on the tube (9), directly downstream of the exhaust line (3). These pressure sensors can be of the capacitive or inductive diaphragm microphone type, piezoelectric microphone or any other type. These two sensors (15) (16) generate electrical signals representative of the pressure wave propagating in the conduit (9). 4 0
Ces signaux électriques sont acheminés à destination d'un calculateur (17) équipés de moyens de traitement et de calcul, pouvant notamment inclure des processeurs de traitement du signal (DSP). Ces moyens de traitement (17) sont programmés pour déterminer l'amplitude de l'onde qui se présentera à la bouche et l'instant où elle s'y présentera, à partir de chaque signal élaboré par les capteurs (15,16), compte tenu de la distance (d) séparant les deux capteurs le long du chemin de propagation des gaz.These electrical signals are routed to a computer (17) equipped with processing and calculation means, which may in particular include signal processing processors (DSP). These processing means (17) are programmed to determine the amplitude of the wave which will appear at the mouth and the instant when it will appear there, from each signal produced by the sensors (15,16), taking into account the distance (d) separating the two sensors along the gas propagation path.
Ce calcul repose sur la détermination de la vitesse de propagation de cette onde à partir du déphasage entre les signaux des capteurs (15) et (16). Il pourra séparer les ondes incidentes se propageant depuis les capteurs vers la bouche des ondes réfléchies se propageant depuis la bouche vers les capteurs.This calculation is based on the determination of the propagation speed of this wave from the phase shift between the signals from the sensors (15) and (16). It can separate the incident waves propagating from the sensors towards the mouth from the reflected waves propagating from the mouth towards the sensors.
Cette élaboration peut tenir compte de différents paramètres et notamment de la forme du conduit en aval des capteurs (15,16) et des pertes de charge correspondantes. D'autres paramètres tels que la température ou autre peuvent être également pris en compte.This development can take into account different parameters and in particular the shape of the conduit downstream of the sensors (15,16) and the corresponding pressure drops. Other parameters such as temperature or the like can also be taken into account.
En fonction, de l'évaluation de cette onde de bouche, les moyens de traitement (17) élaborent un signal de contre-bruit correspondant à l'onde qui combinée avec l'onde de bouche est destinée à réduire l'intensité sonore émise en étant le plus strictement possible opposée à celle-ci.Depending on the evaluation of this mouth wave, the processing means (17) develop a counter-noise signal corresponding to the wave which combined with the mouth wave is intended to reduce the sound intensity emitted by being as strictly as possible opposed to it.
En fonction du temps de propagation estimé de l'onde dans les des gaz d'échappement, les moyens de traitement (17) commandent avec le décalage temporel nécessaire à la compensation des temps de réponse des sources électroacoustiques (20,21) situées à proximité de l'extrémité (10) du conduit (9). Ces sources électro-acoustiques peuvent être de type très variées et notamment être formées par des hauts-parleurs, des chambres de compression, ou autres. Les moyens de traitement sont également programmés pour tenir compte des temps de montée de ces différentes sources électro-acoustiques, correspondant au décalage entre l'émission d'une onde sonore par la source électro-acoustique par rapport au signal électrique de commande.Depending on the estimated propagation time of the wave in the exhaust gases, the processing means (17) control with the time offset necessary to compensate for the response times of the electroacoustic sources (20,21) located nearby. from the end (10) of the conduit (9). These electro-acoustic sources can be of very varied types and in particular be formed by loudspeakers, compression chambers, or others. The processing means are also programmed to take account of the times of rise of these different electro-acoustic sources, corresponding to the offset between the emission of a sound wave by the electro-acoustic source relative to the electrical control signal.
Dans la forme préférable illustrée, les sources électro-acoustiques (20,21) sont disposées en périphérie d'une virole annulaire (22) disposée concentriquement avec le conduit (9). Le centre de symétrie de cette virole (22) correspond donc au centre de l'extrémité (10) du conduit (9), de sorte que le point virtuel correspondant au centre d'émission de l'onde de contre bruit est confondu avec le point d'émission de l'onde de bouche.In the preferable form illustrated, the electro-acoustic sources (20, 21) are arranged at the periphery of an annular ferrule (22) arranged concentrically with the conduit (9). The center of symmetry of this ferrule (22) therefore corresponds to the center of the end (10) of the duct (9), so that the virtual point corresponding to the center of emission of the counter-noise wave is coincident with the emission point of the mouth wave.
Dans la forme illustrée, la virole annulaire (22) est équipée de deux sources électro-acoustiques (20) (21) qui débouchent à l'intérieur de la virole (22). Toutefois, un nombre supérieur des sources peut être envisagé sans sortir du cadre de l'invention. De même, les sources électro-acoustiques de contre-bruit peuvent être disposées non pas dans une virole (22) concentrique, mais présenter une ou plusieurs chambres de sortie orientées parallèlement à la sortie du conduit (9). Les sources électro-acoustiques de contre-bruit peuvent aussi être disposées à proximité de la sortie (10) en les fixant sur tout support approprié.In the illustrated form, the annular ferrule (22) is equipped with two electro-acoustic sources (20) (21) which open out inside the ferrule (22). However, a greater number of sources can be envisaged without departing from the scope of the invention. Similarly, the electro-acoustic sources of counter-noise can be arranged not in a concentric ferrule (22), but have one or more outlet chambers oriented parallel to the outlet of the conduit (9). The electro-acoustic sources of counter-noise can also be placed near the outlet (10) by fixing them to any suitable support.
De façon optionnelle, un capteur supplémentaire (25) est disposé à proximité de l'extrémité (10) du conduit dans une zone où l'onde de bouche et l'onde de contre-bruit se combinent. Ce capteur (25) est relié aux moyens de traitement (17), ce qui permet d'effectuer une contre-réaction permettant de corriger certaines erreurs de traitement.Optionally, an additional sensor (25) is arranged near the end (10) of the duct in an area where the muzzle wave and the counter-noise wave combine. This sensor (25) is connected to the processing means (17), which makes it possible to carry out a feedback making it possible to correct certain processing errors.
En pratique, ces erreurs de correction permettent de modifier certains paramètres de l'algorithme de calcul des signaux de commande des sources de contre-bruit qui varient de façon lente dans le temps tels que notamment la température extérieure ou la pression atmosphérique. En pratique, les capteurs (15,16) sont éloignés des sources de contre-bruit d'une distance (D) de l'ordre du mètre, ce qui autorise un décalage temporel de quelques millisecondes à partir de la captation, pour l'élaboration du signal de contre-bruit et la commande de la source électro-acoustique, en prenant en compte son temps de montée.In practice, these correction errors make it possible to modify certain parameters of the algorithm for calculating the control signals of the counter-noise sources which vary slowly over time, such as in particular the outside temperature or the atmospheric pressure. In practice, the sensors (15, 16) are distant from the sources of counter-noise by a distance (D) of the order of a meter, which allows a time shift of a few milliseconds from the capture, for the development of the counter-noise signal and control of the electro-acoustic source, taking into account its rise time.
Comme déjà évoqué, l'invention est également adaptée pour le traitement des ondes de bouche générées dans un conduit d'admission et ce comme illustré à la figure 2. Dans ce cas, l'onde de bouche a été mise au niveau de l'extrémité (30) d'entrée du conduit (39). Deux capteurs (35,36) sont disposés en amont du filtre à air (38). Les moyens de traitement (37) effectuent le même type de calcul pour l'élaboration de l'onde de contre-bruit qui sera émise par les sources électroacoustiques (40) (42).As already mentioned, the invention is also suitable for the treatment of muzzle waves generated in an intake duct and this as illustrated in FIG. 2. In this case, the muzzle wave has been brought to the level of the end (30) of inlet of the conduit (39). Two sensors (35,36) are arranged upstream of the air filter (38). The processing means (37) perform the same type of calculation for the development of the counter-noise wave which will be emitted by the electroacoustic sources (40) (42).
II ressort de ce qui précède que le dispositif conforme à l'invention présente de multiples avantages et notamment celui d'estimer avec anticipation le bruit qui sera émis par la bouche du conduit, de façon à pouvoir effectuer les corrections nécessaires pour prédéterminer le signal de commande de l'émetteur de contre- bruit. En outre, les capteurs de pression ne subissent par de pressions moyennes élevées dans le cas où le filtre à particules ou le filtre à air sont colmatés. Par ailleurs, les fonctions de transfert plus ou moins complexes des silencieux, et variables lorsqu'un filtre est utilisé, ne sont pas à prendre en compte dans l'algorithme de traitement des signaux. It emerges from the above that the device according to the invention has multiple advantages and in particular that of estimating with anticipation the noise which will be emitted by the mouth of the conduit, so as to be able to carry out the corrections necessary to predetermine the signal of control of the noise canceling transmitter. In addition, the pressure sensors are not subjected to high average pressures if the particle filter or the air filter are clogged. Furthermore, the more or less complex transfer functions of the silencers, and variable when a filter is used, are not to be taken into account in the signal processing algorithm.

Claims

REVENDICATIONS
-1- Dispositif d'atténuation du bruit de bouche généré au niveau d'un conduit d'échappement (9) ou d'admission (39) relié à une source d'écoulement puisée (2) tel qu'un moteur thermique (2) ou un compresseur alternatif caractérisé en ce qu'il comporte : au moins deux capteurs (15) (16) disposés à l'intérieur du conduit, entre la bouche (10) dudit conduit (9) et la source d'écoulement puisée (2) et décalés spacialement l'un par rapport à l'autre ; - des moyens électroniques de traitement (17) des signaux issus desdits capteurs (15) (16), aptes à générer des signaux correspondant à une onde de contre-bruit ; - au moins une source électro-acoustique (20,21) disposée à l'extérieur et à proximité directe de l'extrémité (10) du conduit (9), et commandée par les signaux correspondant à l'onde de contre-bruit-1- Device for attenuating the mouth noise generated at an exhaust (9) or intake (39) conduit connected to a pulsed flow source (2) such as a heat engine (2 ) or an alternative compressor characterized in that it comprises: at least two sensors (15) (16) arranged inside the duct, between the mouth (10) of said duct (9) and the pulsed flow source ( 2) and spatially offset from each other; - electronic means for processing (17) signals from said sensors (15) (16), capable of generating signals corresponding to a counter-noise wave; - at least one electro-acoustic source (20,21) placed outside and in the immediate vicinity of the end (10) of the duct (9), and controlled by the signals corresponding to the counter-noise wave
-2- Dispositif selon la revendication 1, caractérisé en ce que le conduit est équipé d'une cavité (8), jouant le rôle de silencieux ou du filtre à particules notamment, et en ce que les capteurs (15,16) sont disposés entre ladite cavité (8) et l'extrémité (10) du conduit.-2- Device according to claim 1, characterized in that the duct is equipped with a cavity (8), playing the role of silencer or the particulate filter in particular, and in that the sensors (15,16) are arranged between said cavity (8) and the end (10) of the conduit.
-3- Dispositif selon la revendication 1, caractérisé en ce qu'il comporte également au moins un capteur additionnel (24), disposé à proximité de l'extrémité (10) du conduit (9), et relié aux moyens de traitement (17).-3- Device according to claim 1, characterized in that it also comprises at least one additional sensor (24), disposed near the end (10) of the conduit (9), and connected to the processing means (17 ).
-4- Dispositif selon la revendication 1 caractérisé en ce que les capteurs (15,16) sont éloignés de l'extrémité (10) du conduit d'une distance (D) de l'ordre du mètre.-4- Device according to claim 1 characterized in that the sensors (15,16) are distant from the end (10) of the conduit by a distance (D) of the order of a meter.
-5- Dispositif selon la revendication 1, caractérisé en ce que les capteurs (15,16) sont écartés les uns des autres d'une distance (d) de l'ordre du décimètre. -6- Dispositif selon la revendication 1, caractérisé en ce que les sources électroacoustiques (20) (21) sont disposées dans une virole annulaire (22) concentrique avec l'extrémité (10) du conduit (9). -5- Device according to claim 1, characterized in that the sensors (15,16) are spaced from each other by a distance (d) of the order of the decimeter. -6- Device according to claim 1, characterized in that the electroacoustic sources (20) (21) are arranged in an annular ring (22) concentric with the end (10) of the conduit (9).
EP03753666A 2002-09-03 2003-07-31 Active vent noise reduction device for use with an exhaust or intake pipe Withdrawn EP1534939A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0210871A FR2843999B1 (en) 2002-09-03 2002-09-03 ACTIVE MOUTH NOISE ATTENUATION DEVICE AT AN EXHAUST OR ADMISSION PIPE
FR0210871 2002-09-03
PCT/FR2003/002433 WO2004022931A1 (en) 2002-09-03 2003-07-31 Active vent noise reduction device for use with an exhaust or intake pipe

Publications (1)

Publication Number Publication Date
EP1534939A1 true EP1534939A1 (en) 2005-06-01

Family

ID=31503061

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03753666A Withdrawn EP1534939A1 (en) 2002-09-03 2003-07-31 Active vent noise reduction device for use with an exhaust or intake pipe

Country Status (4)

Country Link
EP (1) EP1534939A1 (en)
AU (1) AU2003271828A1 (en)
FR (1) FR2843999B1 (en)
WO (1) WO2004022931A1 (en)

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1512014A (en) * 1974-06-21 1978-05-24 Univ Leeds Ind Service Ltd Method of attenuating longitudinal compression waves travelling in a gas filled duct
JPS59201915A (en) * 1983-04-30 1984-11-15 Hino Motors Ltd Exhaust equipment of engine
US5097923A (en) * 1988-02-19 1992-03-24 Noise Cancellation Technologies, Inc. Active sound attenation system for engine exhaust systems and the like
GB9003959D0 (en) * 1990-02-21 1990-04-18 Ross Colin F Active control of internal combustion engine performance
US5319165A (en) * 1990-04-25 1994-06-07 Ford Motor Company Dual bandpass secondary source
EP0470656A1 (en) * 1990-08-10 1992-02-12 General Motors Corporation Method and apparatus for attenuating engine noise
GB9118779D0 (en) * 1991-08-29 1991-10-16 Active Noise & Vibration Tech Muffler
US5313407A (en) * 1992-06-03 1994-05-17 Ford Motor Company Integrated active vibration cancellation and machine diagnostic system
US5377275A (en) * 1992-07-29 1994-12-27 Kabushiki Kaisha Toshiba Active noise control apparatus
DE59903183D1 (en) 1998-07-22 2002-11-28 Friedmund Nagel DEVICE AND METHOD FOR REDUCING THE NOISE EMISSION IN COMBUSTION ENGINES AND FOR DIAGNOSIS THEREOF
FR2812751B1 (en) * 2000-08-01 2002-11-08 Ecia Equip Composants Ind Auto ACOUSTIC DEVICE FOR AN ACTIVE NOISE MITIGATION SYSTEM

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004022931A1 *

Also Published As

Publication number Publication date
AU2003271828A1 (en) 2004-03-29
FR2843999B1 (en) 2006-01-27
FR2843999A1 (en) 2004-03-05
WO2004022931A1 (en) 2004-03-18

Similar Documents

Publication Publication Date Title
EP0649494B1 (en) Inlet or exhaust line for reciprocating machine
EP1478829B1 (en) Exhaust line and motor vehicle equipped therewith
FR2636189A1 (en) ELECTRONIC NOISE MITIGATION SYSTEM
CA1265063A (en) Methods and means for deafening externally generated noises reaching the eardrum and for improving the clarity of perceived electro-acoustic communications
EP0852793B1 (en) Hybrid active vibration control method and device, particularly for mechanical and acoustic vibration and the like
WO2007003816A2 (en) Method and device for detecting the presence of an exhaust gas treatment system in an exhaust line of an internal combustion engine
FR3073562A1 (en) METHOD AND DEVICE FOR DIAGNOSING A DIFFERENTIAL PRESSURE SENSOR OF A PARTICLE FILTER
FR2955893A1 (en) METHOD AND COMBINATION OF CONTROL INSTALLATIONS FOR DETERMINING THE EXHAUST GAS TEMPERATURE OF A THERMAL ENGINE
FR2551501A1 (en) INTAKE DEVICE FOR AN INTERNAL COMBUSTION AUTOMOTIVE ENGINE
EP1534939A1 (en) Active vent noise reduction device for use with an exhaust or intake pipe
EP3303815B1 (en) Apparatus for damping diffused and radiated pipe noises
FR3061931A1 (en) METHOD AND DEVICE FOR DIAGNOSING THE CHARGE OF A PARTICLE FILTER
EP2375029A1 (en) Device for insulating a cooling circuit
WO2020109322A1 (en) Exhaust train comprising a photoacoustic sensor for measuring at least one concentration of polluting gas, and motor vehicle comprising such an exhaust train
FR2743848A1 (en) Adjustable silencer for air intake of vehicular combustion engine
FR2871193A1 (en) METHOD FOR REGENERATING A PARTICLE FILTER
FR3076318A1 (en) Sound generation device and vehicle exhaust system
FR2678681A1 (en) Silencer for a combustion engine
FR3078994A1 (en) METHOD AND DEVICE FOR DETERMINING THE PRESENCE AND OPERATION OF A PARTICLE FILTER.
Singh et al. A Study on the Effect of an Acoustic Valve in the Exhaust Silencer for Noise Reduction in Automotive Application
FR2497283A1 (en) AIR / FUEL RATIO CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE WITH DOUBLE BODY CARBURETOR
FR2958331A1 (en) Installation defining method for insulation device of sound frequencies in cooling circuit of internal combustion engine of vehicle, involves determining position of insulation device in circuit according to minimal amplitude of outlet wave
FR3014148A1 (en) AIR INTAKE MANIFOLD FOR THERMAL ENGINE COMPRISING AN ACOUSTIC ATTENUATOR
FR2976619A1 (en) System for discharging exhaust gases from internal combustion engine to outer side of sports car, has circuit comprising bent pipe such that angle is formed between axes of displacement of gases upstream and downstream of pipe
FR2852625A1 (en) ACOUSTIC MITIGATION SYSTEM

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20050303

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL LT LV MK

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20060627

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20061108