EP0470153B1 - Aktive schall- und/oder vibrationssteuerung - Google Patents

Aktive schall- und/oder vibrationssteuerung Download PDF

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Publication number
EP0470153B1
EP0470153B1 EP90907216A EP90907216A EP0470153B1 EP 0470153 B1 EP0470153 B1 EP 0470153B1 EP 90907216 A EP90907216 A EP 90907216A EP 90907216 A EP90907216 A EP 90907216A EP 0470153 B1 EP0470153 B1 EP 0470153B1
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EP
European Patent Office
Prior art keywords
vibration
sound
source
sensors
signals
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Expired - Lifetime
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EP90907216A
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English (en)
French (fr)
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EP0470153A1 (de
Inventor
Graham Paul Eatwell
Christopher Mark Dorling
William Richard Hodson
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Noise Cancellation Technologies Inc
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Noise Cancellation Technologies Inc
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Publication of EP0470153A1 publication Critical patent/EP0470153A1/de
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    • 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
    • G10K11/17883—General system configurations using both a reference signal and an error signal the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed
    • 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
    • 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
    • G10K11/17825—Error signals
    • 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
    • G10K2210/121—Rotating machines, e.g. engines, turbines, motors; Periodic or quasi-periodic signals in general
    • 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
    • G10K2210/3024—Expert systems, e.g. artificial intelligence
    • 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
    • G10K2210/3025—Determination of spectrum characteristics, e.g. FFT
    • 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
    • G10K2210/3032—Harmonics or sub-harmonics
    • 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
    • G10K2210/3042—Parallel processing
    • 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
    • G10K2210/301—Computational
    • G10K2210/3051—Sampling, e.g. variable rate, synchronous, decimated or interpolated

Definitions

  • the present invention relates to an active sound or vibration cancelling apparatus for cancelling sound or vibration from a source thereof.
  • the system of the invention can be used even when the fundamental period of vibration is changing rapidly. For example, it can be used to control the engine noise in the interior of a vehicle.
  • the improved apparatus in accordance with the invention uses orthogonal transformations to reduce a multichannel control system to a series of single channel systems and provides a method by which the output of each such system can be adapted to maintain good performance of the control system even when the fundamental frequency of the vibration or sound source is changing.
  • GB-A-2201858 describes methods for adapting filter coefficients.
  • GB-A-1577322 recognises the need for adaption and a later patent specification, GB-B-2107960, describes a simple technique for such a system using a single actuator and sensor. This latter patent specification does not explain how to control vibration where the period is changing, except to suggest that in this case the transform technique should produce frequency components from the lowest expected frequency to the highest, rather than just at frequencies corresponding to the harmonics of the source.
  • a further Patent Specification GB-B-2122052 uses a waveform synthesis technique for vibration control.
  • a sensor and actuator are placed at each of a number of locations. This results in a system with equal numbers of sensors and actuators and a method for adapting the waveform is presented for this special case.
  • the sources and sensors are not colocated and usually more sensors than sources are used in an effort to obtain a better measure of the resulting sound or vibration.
  • EP-A-0043565 discloses an active sound or vibration cancelling apparatus for cancelling sound or vibration from a source thereof, comprising: a source sensing means for producing a source signal related to the phase of unwanted sound or vibration at the source sensing means; sound or vibration sensing means; sound or vibration producing means; analogue-to-digital converter means for sampling the output signals of the sound or vibration sensing means in dependence on the source signal; and processing means responsive to the output of the analogue-to-digital converter means to produce drive signals for the sound or vibration producing means to effect cancellation of noise or vibration from the source thereof.
  • the sound or vibration sensing means comprises a distributed plurality of sound or vibration sensors
  • the sound or vibration producing means comprises a distributed plurality of sound or vibration producing actuators
  • the processing means uses data in the form of singular values representing a singular value decomposition of a matrix representing transfer functions between said plurality of actuators and said plurality of sensors to calculate said drive signals.
  • the signal from each of a plurality of sensors is sampled using an analogue to digital converter (ADC) triggered by a signal related to the position of the source in its cycle.
  • ADC analogue to digital converter
  • the data may be averaged over several cycles to improve accuracy.
  • This gives an almost periodic sequence to which an orthogonal transform, such as the discrete Fourier transform, can be applied.
  • This process is well known for the analysis of periodic signals, and is referred to as "order ratio analysis” or "order locked analysis”.
  • Equation (3.1) The sample signal from the i-th sensor is given by equation (3.1), where I ij (nT) is the response at sensor i, due to an impulse at the j-th controller output, Y i (n) is the n-th value of sensor signal in the absence of any control and T is the sampling interval. J is the number of controller outputs.
  • I ij (nT) the response at sensor i, due to an impulse at the j-th controller output
  • Y i (n) the n-th value of sensor signal in the absence of any control
  • T the sampling interval.
  • J the number of controller outputs.
  • Equation (3.1) can then be written as equation (3.3), where equation (3.4) defines the cyclic impulse response.
  • Equation (3.3) then becomes equation (3.6).
  • Equation (3.6) shows that each harmonic, k, of the system can be considered separately.
  • the control problem is to find the components X j (k) which produce the desired values of R i (k). This problem is complicated because all of the control outputs, X j (k) interact to produce each sensor signal. It is possible, however, to use a technique which transforms the set of coupled equations (3.6) into a set of independent equations.
  • the technique employs a singular value decomposition of the transfer function matrix A ij (kf) for each kf. This gives equation (3.7), where the asterisk denotes complex conjugation.
  • the matrices with complex components U im and V mj represent orthogonal transformations and so have the properties given by equations (3.8) and (3.9), where M is the number of sensors and ⁇ lm is the Kronecker delta.
  • Equation (3.6) can be multiplied by U * li and summed over i to give equation (3.10), to which equations (3.10.1) and (3.10.2) and (3.10.3) are applicable.
  • Equation (3.10) is a single equation for the component (kf) of the desired controller output, which can be solved directly if and are known or, since may be changing, can be solved iteratively using standard adaption algorithms. If the explicit dependence on l and kf is dropped, equation (3.10) reduces to equation (3.11).
  • equation (3.11) and (3.12) gives equation (3.12.1), and from equation (3.11), equation (3.12.2) results.
  • equation (3.15) applies, that is, a different convergence factor is used for each frequency and each principal component.
  • equations (3.9) and (3.10.3) can be used to give equation (3.16).
  • the actuators are not driven too hard, and it is important that the signals to the DAC's are within the correct range.
  • One particular method of limiting the drive amplitudes is to use a minimisation constraint, ⁇ in the algorithm given by equation (3.17).
  • the constraint ⁇ can be adapted after each iteration, that is ⁇ is increased if any of the drive signals x j is too large or reduced if they are all in the desired range.
  • Digital values are stored in a memory device (1), which may for example be a FIFO device. These values are sent to a set of digital to analogue converters (DACs) (2) which are triggered N times per cycle by a train of electrical pulses from a sensor (3). These pulses relate to the position of the source in its cycle.
  • the analogue signals from the DACs are passed through signal conditioners (4) to provide the drive signals for a number of actuators (5).
  • the resulting sound or vibration field is measured by sensors (6).
  • the signals from these sensors are used to adapt the values stored in the memory device (1) so that the sensor signals approach the desired values.
  • the sensor signals are passed through signal conditioners (7) and then sampled in synchrony with the source using analogue to digital converters (8) which are triggered by signals from the position sensor (3). These sampled values are placed in memory device (9) and may be averaged over a number of complete cycles to reduce the effects of signals unrelated to the source.
  • a transform module (10) which may use a discrete Fourier transform, produces components related to the harmonic frequencies of the source for each sensor. The components from the different sensors are then combined in the transform module (11) so as to produce the principal components of sensor signals. Each of these independent components is modified in the adaption module (12) to produce the principal components of the new drive signals.
  • transform module (13) is combined with transform module (13) to produce the frequency components of each drive signal which are then converted to time values via an inverse transform module (15).
  • the new time values then replace those in the memory device (1).
  • the transform modules (11) and (13) and the adaption modules (12) require knowledge of the period or frequency of the source. This may be obtained from the position signal via a frequency counter (14) which contains a real time clock. This method can be used in aircraft cabins where the source of the noise is the propellers or propfans.
  • a control system for controlling the "boom" in automobile interiors is described in published UK Patent Application 2,201,858. It uses the wave shaping or filtering technique described above. The system is designed to adapt on a time scale comparable with delays associated with the propagation time of sound from the actuators to the sensors. In an automobile interior, however there is sound from many sources which are not related to the engine: for example, road noise, wind noise, sound from the in-car entertainment system. This noise contaminates the sensor signals and degrades the performance of the system.
  • the method of this invention uses averaging of the synchronously sampled signals over several cycles. This reduces the level of contamination and improves the performance of the system.
  • the time taken for averaging reduces the ability of the system to track changes in the sound field due to changes in engine speed and load. Therefore, for a given level of contaminating noise, there will be an optimum number of cycles for averaging which will depend upon the rate of change of engine speed and load.
  • the rate of change of engine speed may be obtained from the position signal and engine load may be obtained from additional sensors, such as a pressure sensor in the inlet manifold or throttle position sensor. This information can be used to control the rate of adaption so that optimal performance of the system can be obtained.

Claims (4)

  1. Aktives Schall- oder Vibrationsunterdrückungsgerät zum Unterdrücken von Schall oder Vibrationen, die von einer Quelle erzeugt werden, wobei das Gerät folgendes umfaßt:
    eine Quellenmeßeinrichtung (3) zur Erzeugung eines Quellensignals, das mit der Phase von unerwünschtem Schall oder Vibrationen an der Quellenmeßeinrichtung in Beziehung steht;
    eine Schall- oder Vibrationsmeßeinrichtung (6);
    eine Schall- oder Vibrationserzeugungseinrichtung (5);
    eine Analog-/Digital-Wandlereinrichtung (8) zur Abtastung der Ausgangssignale der Schall- oder Vibrationsmeßeinrichtung in Abhängigkeit von dem Quellensignal; und
    eine Verarbeitungseinrichtung (1, 9, 10, 11, 12, 13, 15), die auf das Ausgangssignal der Analog-/Digital-Wandlereinrichtung reagiert, um Treibersignale für die Schall- oder Vibrationserzeugungseinrichtung (5) zu erzeugen, um die Unterdrückung von Geräuschen oder Vibrationen von deren Quelle zu bewirken,

       dadurch gekennzeichnet, daß die Schall- oder Vibrationsmeßeinrichtung (6) eine verteilte Vielzahl von Schall- oder Vibrationssensoren (6) umfaßt, die Schall- oder Vibrationserzeugungseinrichtung (5) eine verteilte Vielzahl von schall- oder vibrationserzeugenden Aktuatoren (5) umfaßt und die Verarbeitungseinrichtung (1, 9, 10, 11, 12, 13, 15) Daten in der Form von singulären Werten verwendet, die eine Singulärwertzerlegung einer Matrix repräsentieren, welche Übertragungsfunktionen zwischen der Vielzahl von Aktuatoren (5) und der Vielzahl von Sensoren (6) repräsentiert, um die Treibersignale zu berechnen.
  2. Gerät nach Anspruch 1, bei dem die Verarbeitungseinrichtung (1, 9, 10, 11, 12, 13, 15) die Treibersignale unter Bezugnahme auf eine Nachschlagtabelle erzeugt, die Daten enthält, welche die relevanten Übertragungsfunktionen zwischen den Aktuatoren (5) und den Sensoren (6) für eine Vielzahl von diskreten Quellenfrequenzen enthält.
  3. Gerät nach Anspruch 2, bei dem die Verarbeitungseinrichtung (1, 9, 10, 11, 12, 13, 15) zwischen den Nachschlagtabellendaten interpoliert, wenn die Tabelle keine Daten für die momentane Quellengrundfrequenz enthält.
  4. Gerät nach Anspruch 2 oder 3, bei dem die Daten Übertragungsfunktionsdaten für Harmonische der diskreten Quellengrundfrequenzen enthalten.
EP90907216A 1989-04-25 1990-04-20 Aktive schall- und/oder vibrationssteuerung Expired - Lifetime EP0470153B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB8909433A GB2230920B (en) 1989-04-25 1989-04-25 Active sound and/or vibration control
GB8909433 1989-04-25
PCT/GB1990/000617 WO1990013108A1 (en) 1989-04-25 1990-04-20 Active sound and/or vibration control

Publications (2)

Publication Number Publication Date
EP0470153A1 EP0470153A1 (de) 1992-02-12
EP0470153B1 true EP0470153B1 (de) 1996-02-28

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP90907216A Expired - Lifetime EP0470153B1 (de) 1989-04-25 1990-04-20 Aktive schall- und/oder vibrationssteuerung

Country Status (8)

Country Link
EP (1) EP0470153B1 (de)
JP (1) JPH04505221A (de)
AU (1) AU635266B2 (de)
CA (1) CA2049332C (de)
DE (1) DE69025604T2 (de)
ES (1) ES2084028T3 (de)
GB (1) GB2230920B (de)
WO (1) WO1990013108A1 (de)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5485523A (en) * 1992-03-17 1996-01-16 Fuji Jukogyo Kabushiki Kaisha Active noise reduction system for automobile compartment
FR2692709B1 (fr) * 1992-06-18 1994-09-16 Renault Dispositif de contrôle actif du bruit dans l'habitacle d'un véhicule automobile.
DE69423531T2 (de) * 1993-02-02 2000-07-20 Honda Motor Co Ltd Schwingungs/Lärmverminderungsvorrichtung
US5660255A (en) * 1994-04-04 1997-08-26 Applied Power, Inc. Stiff actuator active vibration isolation system
DE19944985B4 (de) * 1999-09-20 2005-04-28 Siemens Ag Messverfahren zur Strommessung mit Rauschunterdrückung
US8302456B2 (en) 2006-02-23 2012-11-06 Asylum Research Corporation Active damping of high speed scanning probe microscope components

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5717027A (en) * 1980-07-03 1982-01-28 Hitachi Ltd Vibration reducing device of electric machinery
JPS58153313A (ja) * 1982-03-08 1983-09-12 Hitachi Ltd 低騒音静止誘導電器
GB2122052B (en) * 1982-06-09 1986-01-29 Plessey Co Plc Reducing noise or vibration
GB8525800D0 (en) * 1985-10-18 1985-11-20 Contranoise Ltd Transfer function generation
WO1988002912A1 (en) * 1986-10-07 1988-04-21 Adaptive Control Limited Active vibration control
JPH01159406A (ja) * 1987-12-15 1989-06-22 Mitsui Eng & Shipbuild Co Ltd プロペラ音の能動消音方法及び装置
GB2222053B (en) * 1988-08-17 1993-03-31 Topexpress Ltd Signal processing means for sensing a periodic signal in the presence of another interfering periodic noise

Also Published As

Publication number Publication date
ES2084028T3 (es) 1996-05-01
CA2049332C (en) 2000-08-01
DE69025604D1 (de) 1996-04-04
GB2230920A (en) 1990-10-31
CA2049332A1 (en) 1990-10-26
EP0470153A1 (de) 1992-02-12
JPH04505221A (ja) 1992-09-10
DE69025604T2 (de) 1996-10-24
GB8909433D0 (en) 1989-06-14
GB2230920B (en) 1993-12-22
WO1990013108A1 (en) 1990-11-01
AU635266B2 (en) 1993-03-18
AU5545690A (en) 1990-11-16

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