Method and device for imaged representation of acoustic objects, a corresponding information program product and a recording support readable by a corresponding computer

• US 20080034869A1
• Filed: 01/30/2004
• Published: 02/14/2008
• Est. Priority Date: 01/30/2003
• Status: Abandoned Application

• Current Assignee: GFaI - Gesellschaft zur Förderung angewandter Informatik e.V.
• Original Assignee: GFaI - Gesellschaft zur Förderung angewandter Informatik e.V.
• Inventors: Heinz, Gerd, Tilgner, Swen, Dobler, Dirk
• Application Number:
  US10/543,950
• Publication Number:
  US 20080034869A1
• Time in Patent Office: Days
• US Class Current: 73/572
• CPC Class Codes: G01H 3/125 for representing acoustic field distribution using optical means G01H9/002; sonar systems for imaging G01S7/56, G01S15/89; acoustic holography G03H3/00

Abstract

The invention relates to a method and device for imaged representation of acoustic objects by taking acoustic cards with the aid of an acoustic set to which a reference image of a measure object is associated. Said invention also relates to an information program product and to a recording support which is readable by a corresponding computer and can be used, in particular for photographic and filmic documentation and for acoustic analysis of noise sources, for example of machines, devices and vehicles. For this purpose an acoustic camera is used. Said camera consists of a microphone assembly of an integrated video camera, a data recording unit connected to a microphone and to an angular sensor, a calibration device and a computer. Said video camera makes it possible to automatically document each measure in such a way that photographic records made by the camera are recorded and inseparably united in a dataframe with recording of the time function of the microphone associated with time-dependent synchronization signals, with all information on a scene and files of the microphone parameters and the data recording device. A time function, a frequency function, acoustical pressure, coordinates, tonality or the correlation with a known time function can be called for each point of an acoustic image by means of a mouse click on said point and a menu called by the mouse right button. Said acoustic camera is also provided with other functions such as automatic illumination which make it possible to select different methods (absolute, relative, manual, minus Delta, Lin/Log, all effective value, pic) for adequately pre-setting a minimum and maximum of a colour scale.

Claims

1-53. -53. (canceled)

54. Process for imaging acoustic objects by using a microphone array to record acoustic maps which have a reference image of the measured object associated with them, characterized in that

the microphone array and an optical camera are arranged in a specifiable position to one another and the optical camera automatically documents at least part of the measurements;

the acoustic map and the optical image field are superimposed by having the object distance and the camera'"'"'s aperture angle define an optical image field on which the acoustic map is calculated;

calculation-relevant parameters of the microphones and the camera of an array are stored in an unmistakable way in a parameter file associated with the array;

amplifier parameters are stored in one or more parameter file(s) which are associated with the amplifier modules or the data recorder;

the microphone array and the amplifier modules or data recorder are each given electronic signatures which unmistakably load the corresponding parameter files;

the calculated acoustic image field is decomposed into subareas whose centers of gravity represent the coordinates of the pixels to be calculated;

acoustic maps are optimally exposed by selecting various methods (absolute, relative, manual, minus_delta, lin/log, all, effective value, peak) to specify the suitable minimum and maximum of a color scale;

synchronization errors of all microphones and amplifier channels are eliminated by compensating the pictures with corresponding parameters from the parameter files of the microphone array and the data recorder;

records of the camera pictures and the associated records of the microphone time functions, time synchronization signals, scene information, and parameter files of the microphone array and the data recorder are stored together with information about this association.

55. Process of claim 54, characterized in that points on the acoustic map have a tuple of delay times determined for them which comprises the delay times of the acoustic signals between the exciting site and the array'"'"'s microphones.

56. Process of claim 54, characterized in that algebraic combinations of the time functions are executed in such a way that when the microphone channel data is accessed the time delays in an associated tuple are evaluated.

57. Process of claim 54, characterized in that the interference values for points on the acoustic map are visualized for

a time point;

or

a sequence of time points.

59. Process of claim 54, characterized in that the result of an algebraic operation such as, e.g., addition, is noted for a time point Tx, for which the common delay time of all channels is eliminated.

60. Process of claim 54, characterized in that, for each microphone of the microphone array, the type, identification sensitivity, coordinates of membrane center (x, y, z), axis orientation (dx, dy, dz), loci of the amplitudes and delay times, and, for the optical camera, the type, aperture, maximum image frequency, and pixel resolutions are stored in a parameter file which is associated with the microphone array and which has an identification number assigned to it, which is referenced with the array'"'"'s hardware signature.

61. Process of claim 54, characterized in that before a measurement it is possible to check the precise superposition and orientation between an optical image and acoustic image by producing a test sound with a calibration tester, which can check the correct superposition of the camera image and the acoustic map.

72. Computer program product comprising a computer-readable storage medium that has a program stored on it which, once it has been loaded into a computer'"'"'s memory, allows the computer to image acoustic objects using a microphone array to record acoustic maps which have a reference image of the measured object associated with them in an imaging process comprising the steps described in claim 54.

73. Computer-readable storage medium that has a program stored on it which, once it has been loaded into a computer'"'"'s memory, allows the computer to image acoustic objects using a microphone array to record acoustic maps which have a reference image of the measured object associated with them in an imaging process comprising the steps described in claim 54.

62. Device for imaging acoustic objects by recording acoustic maps which have a reference image of the measured object associated with them using a microphone array, which has an optical camera integrated into it so that the two form a unit in which the microphone array, a data recorder, and a data processing device exchange microphone data, camera image(s), and time synchronization information through means of data transfer

characterized in that

the device is set up in such a way that

calculation-relevant parameters of the microphones and the camera of an array are stored in an unmistakable way in an array parameter file;

and

synchronization errors of all microphones and amplifier channels are eliminated by compensating the pictures with corresponding parameters from the parameter files of the microphone array and the data recorder.

63. Device of claim 62, characterized in that all microphone data of an array is fed through a common connection (cable or bus) and connected to the data recorder through a common one or more-part plug.

64. Device of claim 62, characterized in that the video camera'"'"'s lead is also integrated into this common connection line.

65. Device of claim 62, characterized in that a microphone array contains a signature chip in the plug connected to the data recorder.

66. Device of claim 62, characterized in that the data recorder can have a calibration test device connected to it which contains a sound producing device.

67. Device of claim 62, characterized in that a unit consisting of the microphone array and a video camera connected in a non-detachable manner is mounted on a tripod so that it can pivot.

68. Device of claim 62, characterized in that microphone arrays having a different number of channels are pin-compatible, allowing them to be connected to a data recorder through the same one or more-part plug type that is identical for various arrays;

unused inputs in the plug can be shorted under some circumstances.

69. Device of claim 62, characterized in that the data recorder is integrated into the microphone array and that this unit is mounted on a tripod so that it can pivot.

70. Device of claim 62, characterized in that a collapsible microphone array for measuring over great distances advantageously consists of a video camera and at least three tubes, which are each equipped with n microphones and which do not lie in a plane and which are connected with at least two joints.

71. Device of claim 62, characterized in that an acoustically transparent microphone array for two-dimensional indoor measurements advantageously consists of a video camera and microphones arranged at equal distances on a ring.