EP0342353A2 - Dispositif pour atténuer le niveau du bruit dans une automobile - Google Patents

Dispositif pour atténuer le niveau du bruit dans une automobile Download PDF

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Publication number
EP0342353A2
EP0342353A2 EP19890106308 EP89106308A EP0342353A2 EP 0342353 A2 EP0342353 A2 EP 0342353A2 EP 19890106308 EP19890106308 EP 19890106308 EP 89106308 A EP89106308 A EP 89106308A EP 0342353 A2 EP0342353 A2 EP 0342353A2
Authority
EP
European Patent Office
Prior art keywords
arrangement according
noise
loudspeaker
motor vehicle
arrangement
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.)
Granted
Application number
EP19890106308
Other languages
German (de)
English (en)
Other versions
EP0342353A3 (fr
EP0342353B1 (fr
Inventor
R. Dr. Freymann
R. Beer
R. Schmaderer
K. Stricker
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.)
Bayerische Motoren Werke AG
Original Assignee
Bayerische Motoren Werke AG
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 Bayerische Motoren Werke AG filed Critical Bayerische Motoren Werke AG
Publication of EP0342353A2 publication Critical patent/EP0342353A2/fr
Publication of EP0342353A3 publication Critical patent/EP0342353A3/fr
Application granted granted Critical
Publication of EP0342353B1 publication Critical patent/EP0342353B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • G10K11/17853—Methods, e.g. algorithms; Devices of the filter
    • 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
    • G10K11/1781—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17821—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the input signals only
    • G10K11/17823—Reference signals, e.g. ambient acoustic environment
    • 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
    • G10K11/17873—General system configurations using a reference signal without an error signal, e.g. pure feedforward
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/128—Vehicles
    • G10K2210/1282—Automobiles
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3046—Multiple acoustic inputs, multiple acoustic outputs
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3216—Cancellation means disposed in the vicinity of the source
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3227—Resonators
    • G10K2210/32272—Helmholtz resonators
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/50—Miscellaneous
    • G10K2210/509—Hybrid, i.e. combining different technologies, e.g. passive and active

Definitions

  • the invention relates to an arrangement for reducing the noise level in the interior of a motor vehicle with the features of the preamble of claim 1.
  • the invention has for its object to reduce the noise level in the interior of a vehicle in one or more frequency range (s), the frequencies of which are related to the natural cavity frequencies of the interior, by active damping of the natural cavity vibration frequencies at all locations in the vehicle interior.
  • the design of the noise sensor as a Helmholtz resonator with a microphone accommodated therein ensures stable control and suitable filtering of the recorded noise signal without a sensitive reaction to changes in the acoustic transmission behavior of the vehicle interior, which result, for example, from opening the doors, windows or sunroof .
  • the Helmholtz resonator thus acts as an acoustic filter with the advantage over conventional electronic filters that it has a very time-stable transmission behavior due to the very low filter attenuation required here.
  • the Helmholtz resonator is preferably tuned to the cavity natural frequency to be damped.
  • the damping can be done by a damping material, such as cotton, wool or the like, which is accommodated in the resonator neck or resonator volume of the Helmholtz resonator.
  • noise sensor designed according to the invention is that it can be installed very close to the loudspeaker or loudspeakers, which act as actuators in the control loop. In this way, instabilities due to feedback effects can be avoided even at high control loop gains.
  • a plurality of noise sensors with microphones accommodated in Helmholtz resonators are provided, the individual Helmholtz resonators each being matched to different natural cavity frequencies of the motor vehicle.
  • the control device can be designed very simply in the arrangement according to the invention.
  • the output signals of the noise sensors are connected in parallel, the output signal of each noise sensor being individually amplified or weakened and undergoing a phase shift.
  • the output signals of the noise sensors are then added in at least one summing amplifier and switched to the loudspeakers acting as actuators.
  • the arrangement with several noise sensors opens up the possibility of accommodating them at several locations in the vehicle interior where high sound pressures of the relevant cavity natural frequencies prevail.
  • a microphone 3 is arranged in the interior 2 of a car 1 in the driver's head area, the output signal of which is fed to a controller 4.
  • the controller 4 generates an actuating signal which is fed to a loudspeaker 5 which is also arranged in the interior, for example the loudspeaker of a radio device.
  • the sinusoidal signal in the conventional arrangement oscillates with a phase which is shifted relative to the phase of the actual signal detected by the microphone 3 such that the sound signal emitted by the loudspeaker 5 just cancels a certain frequency of the noise signal detected in the driver's head area.
  • Figure 2 shows the measured sound pressure distribution of the cavity resonance vibration with the lowest frequency of a particular motor vehicle.
  • the natural frequency of this vibration is in the order of 75 Hz for vehicles of the middle and upper class.
  • the next higher natural cavity frequency is in the range of approx. 150 Hz.
  • the numerical values for the sound pressure in decibels (db) show that the maxima of the sound pressure distribution are in the area of the front footwell (117.5 db) and in the area of the rear passenger area (113 db).
  • FIG. 3 shows a diagram with a real abscissa and an imaginary ordinate of the Nyquist stability locus of an open control loop with a profile, the implementation of which results in active damping leading to a reduction in the noise level at all locations in the vehicle interior.
  • E denotes the cavity natural frequency to be damped.
  • FIG. 4 shows schematically the structure of a simple arrangement according to the invention.
  • a noise sensor comprises a Helmholtz resonator, which is designed as a rectangular hollow body 10 with an opening 11 in a side face, and a microphone 12, which is received within the hollow body 10 and whose output signal is fed to a control device 13.
  • the control device 13 generates an actuating signal which is forwarded to a loudspeaker 14 arranged at or near the location of a sound pressure maximum (according to FIG. 2).
  • the Helmholtz resonator 10 is tuned to a specific cavity natural frequency of the respective motor vehicle to be damped, the noise level of which is to be reduced in the interior.
  • the Helmholtz resonator 10 can be embedded by a porous damping materials, such as cotton, wool or the like, are individually prepared.
  • the loudspeaker 14 is arranged in places in the interior where maximum sound pressures prevail, in the example according to FIG. 2 in the area of the rear shelf 6 or in the footwell 7, as is customary for radio loudspeakers, so that the loudspeakers which are provided anyway can be used.
  • FIG. 5 shows the filtering effect of the noise sensor with microphone 12 described in FIG. 4 in the Helmholtz resonator 10: While FIG. 5a) shows several sound pressure peaks in the range of different natural frequencies, which are detected by a simple microphone without a Helmholtz resonator, the Figure 5b) the filter effect when measured at the same location with a microphone, which is arranged according to Figure 4 in a Helmholtz resonator. This enables a targeted approach to reducing the sound pressure generated by a certain natural frequency.
  • the arrangement according to FIG. 4 is accommodated in a vehicle according to FIG. 6, for example.
  • the same reference numerals as in FIG. 4 are used in FIG. 6.
  • the noise sensor comprising the microphone 12 and the Helmholtz resonator 10 is arranged in the area of the rear shelf 6 near the rear speakers 14, which are also accommodated in this area.
  • the control device 13 has two outputs which act on the two loudspeakers 14, 14.
  • FIG. 7 shows the result of the measure according to FIG. 6, the dashed curve showing the sound pressure versus frequency without the described measures of the invention, and the solid curve showing the sound pressure in the interior versus frequency when used represent the measures according to the invention.
  • Figures 8 and 9 show arrangements with which a sound pressure reduction for several cavity natural frequencies of a vehicle is possible.
  • Four noise sensors 10a, 10b, 10c, 10d are provided with corresponding microphones 12a, 12b, 12c, 12d, which are tuned to frequencies f a , f b , f c , f d , which correspond to particularly pronounced cavity natural frequencies.
  • each sensor signal is input into a series circuit, each with an amplifier 15a to 15d, a phase shifter 16a to 16d and a filter 17a to 17d, the series circuits for the individual sensor signals lying in parallel, and in the embodiment according to FIG. 8 fed to a common summing amplifier 18 , where the sensor signals are summed and input to a power amplifier 19 for three loudspeakers 20, 21, 22.
  • the loudspeakers are arranged at various locations in the vehicle interior which are favorable for noise reduction and, as stated above, can coincide with the usual accommodation locations for the radio loudspeakers.
  • Each power amplifier 19A, 19B supplies its own group of three loudspeakers 20, 21, 22 and 23, 24, 25.
  • control device 13 can be implemented using analog or digital technology, in which case a digital computer (not shown) can take over the signal processing.
  • Characteristic of the arrangement according to FIGS. 8 and 9 is the parallel arrangement of the series circuit 15, 16, 17 for each sensor output signal. In this way, individual signal processing can be achieved in adaptation to the individual tuning of the associated noise sensor 10, 12 before the signals are combined in the summing amplifiers 18.
  • the filters 17 can comprise low-pass, high-pass, band-pass or blocking filters.
  • control device 13 is of a simple construction, as shown in FIGS. 8 and 9.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
EP89106308A 1988-05-18 1989-04-10 Dispositif pour atténuer le niveau du bruit dans une automobile Expired - Lifetime EP0342353B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3816921 1988-05-18
DE3816921A DE3816921A1 (de) 1988-05-18 1988-05-18 Anordnung zur verminderung des geraeuschpegels im innenraum eines kraftfahrzeugs

Publications (3)

Publication Number Publication Date
EP0342353A2 true EP0342353A2 (fr) 1989-11-23
EP0342353A3 EP0342353A3 (fr) 1991-03-20
EP0342353B1 EP0342353B1 (fr) 1993-08-11

Family

ID=6354628

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89106308A Expired - Lifetime EP0342353B1 (fr) 1988-05-18 1989-04-10 Dispositif pour atténuer le niveau du bruit dans une automobile

Country Status (2)

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EP (1) EP0342353B1 (fr)
DE (2) DE3816921A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4015313A1 (de) * 1990-05-12 1991-11-14 Opel Adam Ag Aktives geraeuschminderungssystem fuer den innenraum von kraftfahrzeugen
GB2234137B (en) * 1989-07-18 1994-01-12 Messerschmitt Boelkow Blohm A device for the detection and location of sound waves
EP0586831A3 (fr) * 1992-08-13 1994-03-30 Bayerische Motoren Werke Ag
WO1996031872A1 (fr) * 1995-04-04 1996-10-10 Technofirst Procede et dispositif personnels d'attenuation acoustique active a reponse impulsionelle invariante
EP0916536A3 (fr) * 1997-11-13 2000-12-20 DORNIER GmbH Dispositif pour la réduction des variations périodiques de pression d'un courant externe qui coule autour d'une ouverture d'une cavité

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH083395B2 (ja) * 1988-09-30 1996-01-17 株式会社東芝 冷却装置の消音装置
DE19742741C2 (de) * 1997-09-27 2001-08-16 Audi Ag Vorrichtung zur aktiven tieffrequenten Störgeräuschunterdrückung in Kraftfahrzeugen
DE102004016689A1 (de) * 2004-04-05 2005-10-27 Volkswagen Ag Verfahren und Vorrichtung zum Verbessern von Klangeigenschaften in einem Fahrzeug
DE102007032600A1 (de) * 2007-07-11 2009-01-15 Deutsches Zentrum für Luft- und Raumfahrt e.V. Vorrichtung und Verfahren zur Verbesserung der Dämpfung von akustischen Wellen
DE102010021039B4 (de) * 2010-05-19 2015-02-12 Magna Car Top Systems Gmbh Dach für einen Personenkraftwagen

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2518805A (en) * 1945-08-24 1950-08-15 Massa Frank Resonant chamber for microphones
FR1444097A (fr) * 1965-05-17 1966-07-01 Renault Procédé et dispositif pour amortir les résonances acoustiques dans l'habitacle d'un véhicule
DE3106029A1 (de) * 1981-02-19 1982-09-09 Volkswagenwerk Ag, 3180 Wolfsburg "verfahren und anordnung zur verringerung des geraeuschpegels im kopfbereich von kraftfahrzeuginsassen"
ZA825676B (en) * 1981-08-11 1983-06-29 Sound Attenuators Ltd Method and apparatus for low frequency active attennuation
JPS599699A (ja) * 1982-07-07 1984-01-19 日産自動車株式会社 自動車の車室内音場制御装置
FR2531023B1 (fr) * 1982-08-02 1987-04-30 Peugeot Dispositif d'attenuation du bruit dans l'habitacle d'un vehicule automobile
FR2533100B1 (fr) * 1982-09-09 1986-06-27 Sintra Alcatel Sa Procede et dispositif d'attenuation de bruits parasites
GB8328997D0 (en) * 1983-10-31 1983-11-30 Secr Defence Active noise reduction
DE3612204A1 (de) * 1986-04-11 1987-10-15 Audi Ag Vorrichtung zur geraeuschminderung

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2234137B (en) * 1989-07-18 1994-01-12 Messerschmitt Boelkow Blohm A device for the detection and location of sound waves
DE4015313A1 (de) * 1990-05-12 1991-11-14 Opel Adam Ag Aktives geraeuschminderungssystem fuer den innenraum von kraftfahrzeugen
EP0457176A3 (en) * 1990-05-12 1992-09-02 Adam Opel Aktiengesellschaft Active noise reduction system for the interior of motor vehicles
EP0586831A3 (fr) * 1992-08-13 1994-03-30 Bayerische Motoren Werke Ag
WO1996031872A1 (fr) * 1995-04-04 1996-10-10 Technofirst Procede et dispositif personnels d'attenuation acoustique active a reponse impulsionelle invariante
FR2732807A1 (fr) * 1995-04-04 1996-10-11 Technofirst Procede et dispositif personnels d'attenuation acoustique active, siege equipe du dispositif correspondant, et espace a attenuation acoustique active obtenu
US5987144A (en) * 1995-04-04 1999-11-16 Technofirst Personal active noise cancellation method and device having invariant impulse response
EP0916536A3 (fr) * 1997-11-13 2000-12-20 DORNIER GmbH Dispositif pour la réduction des variations périodiques de pression d'un courant externe qui coule autour d'une ouverture d'une cavité

Also Published As

Publication number Publication date
DE3816921A1 (de) 1989-11-30
EP0342353A3 (fr) 1991-03-20
EP0342353B1 (fr) 1993-08-11
DE58905218D1 (de) 1993-09-16

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