Abstract:
A method for detecting and reducing an offensive noise in a vehicle having an engine. A noise is sensed in an area of interest of the vehicle. The area of interest contains a plurality of parts capable of generating the offensive noise. The sensed noise is analyzed to determine components of the noise. The offensive noise is determined based on the sensed noise and the determined noise components. Which one of the plurality of offensive noise generating parts is generating the offensive noise is determined. The offensive noise generating part is affected to reduce the offensive noise coming therefrom and thereby reducing the offensive noise in the area of interest of the vehicle.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates generally to a method and system for detecting, analyzing, and reducing an offensive noise in a vehicle, and more particularly to a method and system for determining a location of an offensive noise component and implementing a countermeasure to reduce or eliminate the offensive noise component.  
           [0003]    2. Description of Related Art  
           [0004]    An operating vehicle produces noise that is audible in the passenger compartment of the vehicle. The audible noise is comprised of a plurality of noise components of differing frequencies from a variety of different sources. The sources include the contact of the wheels to the road, the running engine, and the wind moving past the operating vehicle.  
           [0005]    Some portions of the audible noise are desirable, and other portions of the audible noise offensive to an operator and passenger in the passenger compartment of the vehicle. The offensive noise can negatively impact the quality, enjoyment and marketability of the vehicle. Further, variation of offensive noise levels of different vehicles of the same model, and of different models of vehicles, is problematic for quality assurance purposes. Therefore, it is desirable to identify the offensive noise, find a source of the offensive noise, and reduce or eliminate the offensive noise in the passenger compartment of a vehicle.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a method for detecting and reducing an offensive noise in a vehicle having an engine. In the method according to the invention, a noise is sensed in an area of interest of the vehicle. The area of interest contains a plurality of parts capable of generating the offensive noise. The sensed noise is analyzed to determine components of the noise. The offensive noise is determined based on the sensed noise and the determined noise components. Which one of the plurality of offensive noise generating parts is generating the offensive noise is determined. The offensive noise generating part is affected to reduce the offensive noise coming therefrom and thereby reducing the offensive noise in the area of interest of the vehicle.  
           [0007]    In accordance with another aspect of the invention, a method is provided for employing a noise-reducing countermeasure in a vehicle having an engine. Noise is sensed in a passenger compartment of the vehicle. The sensed noise is analyzed to determine an offensive noise component. The offensive noise component is sensed in a second area spaced from the passenger compartment. The offense noise component is sensed to determine a part that is a source of the offensive noise component. The part is scanned with a laser vibrometer to determine a location on the part from which the offensive noise component emanates. A countermeasure at or near the location on the part is determined. Implementing the countermeasure can reduce the offensive noise component of the noise sensed in the passenger compartment.  
           [0008]    The present invention also provides a system for determining a location of an offensive noise component in a vehicle having an engine. The system includes a noise detection device that detects noise. A noise analyzer analyzes the noise to determine the offensive noise component of the noise. A sound intensity scanner scans an area of interest to determine the area of highest intensity of the offensive noise component to identify a part that generates the offensive noise component. A laser vibrometer scans the part to determine where on the part the offensive noise component emanates from. In another aspect of the invention, a countermeasure can be determined based on the location and the part. Implementing the countermeasure reduces or eliminates the offensive noise component. The system can then double check the passenger compartment to ensure that the countermeasure had the effect of reducing or eliminating the offensive noise. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    These and further features of the invention will be apparent with reference to the following description and drawings, wherein:  
         [0010]    [0010]FIG. 1 is a schematic block diagram of an apparatus for use with a method according to the present invention;  
         [0011]    [0011]FIG. 2 is a schematic view of an exemplary part with a grid overlay of a method in accordance with the invention;  
         [0012]    [0012]FIG. 3 is a flow chart of a method in accordance with an aspect of the invention; and  
         [0013]    [0013]FIG. 4 is a flow chart of a method in accordance with another aspect of the invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0014]    A schematic block diagram of an offensive noise detection, analysis, location and reduction system  100  in accordance with the present invention is shown in FIG. 1. The system  100  is for use on a vehicle having an engine while the engine is running. The system  100  detects and analyzes noise, and a location from which the noise emanates, so that an appropriate counter-measure can be determined and implemented based on the noise emanating location.  
         [0015]    The system  100  includes a noise detection device or detector  1   10 , a noise analyzer  120  that communicates with the detector  110 , and a noise location system or locator  130  that communicates with the analyzer  120 . The locator  130  includes a noise intensity sensor  134  and a laser vibrometer  136 . An input device or microphone  140  communicates with the detector  110 . A memory device  144  communicates with both the detector  110  and the analyzer  120 . The analyzer  120  can optionally also communicate with an output device or memory  154 , if present.  
         [0016]    The detector  110  detects ambient noise in a first area, for example a passenger compartment in the vehicle. The noise is detected with reference to variables in predetermined ranges. The variables can include engine revolutions per minute (RPM) and the volume of the passenger compartment. The range of RPM can include from idle to racing, and the range of space can be from passenger side to drivers side, and can be subdivided into front and rear seating areas, and so forth. The noise is sensed by the microphone  140 , which provides input data to the detector  110 .  
         [0017]    The detector  110  communicates the input data to the analyzer  120 . The analyzer  120  analyzes the noise input data to determine the components or frequencies of the noise. The analyzer  120  identifies which component is the offensive noise or frequency. Information identifying the offensive noise is communicated to the locator  130  and/or the optional memory  154 . If the offensive noise information is communicated to the memory  154 , the memory  154  stores the information for retrieval and later use.  
         [0018]    When the offensive noise information is communicated to the locator  130 , the sound intensity sensor  134  scans an area to determine generally the location from which the offensive noise emanates. For example, first the sound intensity sensor  134  can be set using the offensive noise information so as to detect the offensive noise from the total noise generated by the running engine. Next, the vehicle engine is run, and the sound intensity sensor  134  scans the vehicle engine compartment to determine which of the engine parts of the running engine is generating the offensive noise that was detected in the passenger compartment of the vehicle.  
         [0019]    When the sound intensity sensor  134  determines which of the engine parts is the part generating the offensive noise, that part can be scanned with the laser vibrometer  136 . Generally, the laser vibrometer  136  scans the part while the engine is running to determine a location on the part that generates the offensive noise. If possible, the part may be scanned while operated independent of the engine.  
         [0020]    With reference to FIG. 2, a schematic illustration  200  of a method in accordance with the invention is shown. The illustration  200  includes a schematic representation of an engine part  210 , which has been found via the sound intensity scanner  134 , to generate the offensive noise while the engine is running. An imaginary grid  220  overlays the engine part  210 . The laser vibrometer  136  scans the part  210  with reference to the grid  220  to determine or identify the specific location from which the offensive noise (hereinafter referred to as the “noise source”) emanates relative to the grid  220 . The noise source, as viewed by the laser vibrometer, vibrates at the offensive frequency previously identified by the sound intensity sensor  134  and/or detector  110 , and will be readily apparent.  
         [0021]    Based on the noise source or grid coordinates, an appropriate countermeasure is selected. The countermeasure can be, for example, re-engineering, or either adding material to the generation location or removing material from the noise source. For example, if the noise source is a protruding ridge of metal that vibrates during operation of the engine, the ridge may be strengthened or stiffened by adding additional metal to the ridge. Alternatively, if the ridge in this example serves no or an unimportant function, the ridge itself may be removed. Further, the shape of the ridge can be altered or the material from which the ridge is made can be replaced with a different material. The countermeasure can also be a combination of the foregoing options. The preferred countermeasures are strengthening or weakening the noise source.  
         [0022]    After implementing the countermeasure, the detector  110  can resample the noise in the passenger compartment. The analyzer  120  analyzes the resampled noise to determine if the offensive noise is reduced or eliminated. If the offensive noise has not been reduced to a satisfactory level or eliminated by the implementation of the countermeasure, an additional or different countermeasure is applied to the generation location or the process is repeated to determine if there are additional locations generating the offensive noise during operation of the vehicle.  
         [0023]    With reference to FIG. 3, a flow chart  300  of the steps of a method in accordance with the present invention is shown. In block  310  a noise is sensed. This can be accomplished, for example, by using the detector  110 . The sensed noise is analyzed in block  320 . The analysis of block  320  determines which is the offensive noise of the sensed noise in block  330 , including the frequency or frequencies constituting the offensive noise. A second area space from the first area is scanned for the offensive noise determined in block  330 . The sensing in the second area determines or identifies which part is generating the offensive noise in block  340 . Having identified the part in block  340 , the part&#39;s surface is scanned in block  350  with a laser vibrometer to determine a location (i.e., noise source) on the part that is generating the offensive noise. A countermeasure is determined in block  360  based on the determined location (noise source) on the part.  
         [0024]    With reference to FIG. 4, a flow chart  400  of the steps of a method in accordance with the present invention is shown. In block  410  a noise is sensed in a passenger compartment of a vehicle while the engine is running, that is, the vehicle is being operated. The sensed noise is analyzed in block  420  to determine or isolate the offensive noise component from the sensed noise. A sound intensity scanner senses a second area, for example, in a second area outside of or spaced from the passenger compartment to identify a part that is generating the offensive noise component, as shown in block  430 . Once the part is identified, the part&#39;s surface is scanned in block  440  to determine a location (noise source) on the part, for example a portion of the part housing, from which the offensive noise component emanates. In block  450 , a countermeasure is determine based on the part and/or the location of part relative to the passenger compartment, and further on the location of the noise source, which generates the offensive noise component of the noise. The countermeasure is implemented in block  460  at or near the noise source on the part so as to reduce or eliminate the offensive noise component of the sensed noise in the passenger compartment of the vehicle.  
         [0025]    The embodiments described herein are examples of structures, systems and methods having elements corresponding to the elements of the invention recited in the claims. This written description may enable those skilled in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the invention recited in the claims. The intended scope of the invention thus includes other structures, systems and methods that do not differ from the literal language of the claims, and further includes other structures, systems and methods with insubstantial differences from the literal language of the claims.