Patent Abstract:
A method of emanating a sound from a vehicle comprising detecting a speed of the vehicle, and emanating a speed sound, including emanating a sound profile and changing at least one of a sound pressure level and a pitch of the sound profile in relation to the speed of the vehicle changing. The method further comprises ceasing emanation of the speed sound upon the speed of the vehicle increasing from below a first threshold to above the first threshold, and resuming emanation of the speed sound upon the speed of the vehicle decreasing from above a second threshold to below the second threshold, the second threshold being less than the first threshold.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. patent application Ser No. 13/402,090, filed on Feb. 22, 2012. The entire contents of U.S. patent application Ser. No. 13/402,090 is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to a system and method of emanating a sound from a vehicle. More specifically, the present invention relates to a system and method of emanating a sound from a vehicle based on intent to move the vehicle. 
         [0004]    2. Background Information 
         [0005]    Electric and hybrid vehicles are becoming increasingly popular for reasons such as rising fuel costs and environmental concerns. A secondary advantage of the shift toward widespread use of electric vehicles is the reduction of ambient noise which is emanated by an internal combustion engine (ICE) used in most vehicles today. With 100% electric power running the vehicle, generally only tire noise and some slight electric motor noise is generated during operation of fully electric vehicles. Although this greatly reduces noise pollution, this lack of noise can make it difficult for pedestrians to detect the presence of a vehicle. That is, pedestrians are highly reliant on ICE noise to detect the presence of vehicles, especially when the pedestrian is hearing or visually impaired. 
         [0006]    One attempted solution to enable better pedestrian detection of the vehicle is to generate a vehicle sound for pedestrians (VSP). For example, a vehicle can be controlled to emit a synthetic ICE sound during operation of the vehicle, thereby enabling detection of the electric vehicle in the same way as ICE vehicles. Other attempts to generate sounds can include, for example, generating an unpleasant horn-like sound at an ambient noise frequency, or generating a sound having peaks at an ambient noise frequency. 
       SUMMARY 
       [0007]    It has been discovered that it is desirable to control the vehicle to emit a VSP at appropriate times to warn pedestrians and to refrain from emitting a VSP at unnecessary times. For example, if a vehicle is idling in a driveway in the morning to warm up the passenger cabin on a cold day, the VSP being emitted may annoy neighbors trying to sleep. Also, if a driver is stopped in traffic on a hot day with the vehicle windows down, the driver and drivers of other vehicles may become annoyed hearing the VSP through the open windows. Furthermore, since the National Highway Traffic Safety Administration (NHTSA) may prohibit VSP systems from including turn off switches, a driver may be unable to temporarily disable the VSP system during times when VSP emission is unnecessary. 
         [0008]    In view of the state of the known technology, one aspect of the present invention provides a method of emanating a sound from a vehicle comprising detecting a speed of the vehicle, and emanating a speed sound, including emanating a sound profile and changing at least one of a sound pressure level and a pitch of the sound profile in relation to the speed of the vehicle changing. The method further comprises ceasing emanation of the speed sound upon the speed of the vehicle increasing from below a first threshold to above the first threshold, and resuming emanation of the speed sound upon the speed of the vehicle decreasing from above a second threshold to below the second threshold, the second threshold being less than the first threshold. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Referring now to the attached drawings which form a part of this original disclosure: 
           [0010]      FIG. 1  is a schematic view illustrating an example of components of a system for emanating a sound from a vehicle according to a disclosed embodiment; 
           [0011]      FIGS. 2A and 2B  illustrate an exemplary process performed by the system shown in  FIG. 1  to emanate the sound from the vehicle according to disclosed embodiments; 
           [0012]      FIG. 3  is an exemplary graphical representation of the process shown in  FIGS. 2A and 2B  during vehicle forward movement at low speed; 
           [0013]      FIG. 4  is a variation to the graphical representation shown in  FIG. 3  illustrating exemplary operations that can be performed when the vehicle movement state does not indicate an intent to move the vehicle at or about the time that the vehicle comes to a stop; 
           [0014]      FIG. 5  is a variation to the graphical representation shown in  FIG. 3  illustrating exemplary operations that can be performed when the speed of the vehicle reaches a predetermined speed; and 
           [0015]      FIG. 6  is an exemplary graphical representation of the process shown in  FIGS. 2A and 2B  during vehicle reverse movement. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0016]    Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
         [0017]    Referring initially to  FIG. 1 , a vehicle sound emanating system  10  for use in a vehicle  12  is illustrated in accordance with an embodiment of the present invention. The vehicle  12  can be an electric or hybrid vehicle as understood in the art, and can be any type of vehicle such as a car, truck, van, SUV and so on. The vehicle sound emanating system  10  includes a controller  14  and a vehicle sound production (VSP) module  16  that generates a sound that can serve as an audible alert as discussed in more detail below. As understood by one skilled in the art, the controller  14  preferably includes a microcomputer with a control program that controls the vehicle sound emanating system  10  as discussed herein. The controller  14  can also include other conventional components such as an input interface circuit, an output interface circuit, and storage devices such as a ROM (Read Only Memory) device and a RAM (Random Access Memory) device. The RAM and ROM store processing results and control programs that are run by the controller  14 . The controller  14  is operatively coupled to the components of the vehicle sound emanating system  10 , and to the components of the vehicle  12  as appropriate, in a conventional manner. It will be apparent to those skilled in the art from this disclosure that the precise structure and algorithms for the controller  14  can be any combination of hardware and software that will carry out the functions of the present invention. 
         [0018]    The controller  14  receives signals from the start switch  18 , accelerator position sensor  20 , speed sensor  22 , brake state detector  24  and transmission state detector  26 , and controls the VSP module  16  based on those signals as discussed in more detail below. The vehicle sound emanating system  10  can further include a VSP switch  28  that provides on/off signals to the VSP module  16  that enables a user to turn the VSP module  16  on and off. The VSP module  16  provides signals to at least one audio component  30 , such as a speaker arrangement, to cause the audio component  30  to generate an audible alert as discussed in more detail below. The terms “sound” and “audible alert” can be used interchangeably herein. 
         [0019]    Specifically, the controller  14  controls the VSP module  16  to emanate a sound from the vehicle  12  according to the exemplary process as shown in  FIGS. 2A and 2B  and in the graphs as shown in  FIGS. 3-6 . For purposes of the embodiments described herein, the terms “continuously,” “continuous” and any variations or synonyms thereof as used to modify terms such as “sound,” “signal,” “emanating”, “emanate,” “emit” and so on refer to the outputting or emanation of a sound profile, sound or signal in a manner that is perceptible as continuous (i.e., without pauses or gaps) by a human having normal hearing. In other words, for example, “continuously emanating a sound” refers to the continuous emanation of a sound, as well as the emanation of sound profile with pauses, gaps, dead spots, etc., in a manner such that the sound profile is perceived as a continuous sound profile by a human having normal hearing even though the actual emanation is not in fact continuous. 
         [0020]    As shown in  FIGS. 2A and 2B , the process begins when the controller  14  determines based on signals from the start switch  18  (e.g., an ignition or starter) that the vehicle  12  is started from an “off” state to an “on” or running state in step  100 . During the vehicle starting period, the controller  14  controls the VSP module  16  to refrain from emanating an audible alert sound from the audio component  30  in step  110 . The vehicle starting period is shown as the period between times t 0  and t 1  in, for example,  FIG. 3 .  FIG. 3  is an exemplary graphical representation of the process shown in  FIGS. 2A and 2B  during vehicle forward movement at low speed as discussed in more detail below. 
         [0021]    The controller  14  then determines in step  120  whether a vehicle movement state indicates intent to move the vehicle  12  from a stationary state. The controller  14  can determine that the vehicle  12  is in a stationary state when, for example, the transmission state detector  26  indicates that the vehicle transmission is in a park position or in a neutral position, or the brake state detector  24  indicates the emergency brake is on. Naturally, the transmission can be an automatic transmission or a manual transmission as understood in the art. The controller  14  can also determine that the vehicle  12  is in a stationary state when, for example, the speed sensor  22  indicates that the vehicle  12  is not moving, regardless of the positions of the transmission, the brake and the emergency brake. When the vehicle  12  is in the stationary state, such as during the period between t 1  and t 2  in  FIG. 3 , the controller  14  continues to receive signals from the brake state detector  24  and the transmission state detector  26 . The controller  14  can detect the vehicle movement state from, for example, at least a transmission state and a brake state of the vehicle  12 . The controller  12  thus determines in step  120  whether the vehicle movement state indicates intent to move the vehicle  12  based on the transmission state and the brake state. If the brake has not been moved into the brake depressed state, the controller  14  controls the VSP module  16  to continue to refrain from emanating the sound. That is, the controller  14  controls the VSP module  16  to continue to refrain from emanating the sound in step  110  during a vehicle running state after the vehicle starting period and before a brake of the vehicle  12  is moved into a brake depressed state while the vehicle  12  is in a stationary state. In other words, the controller  14  controls the VSP module  16  to refrain from emanating the sound when the vehicle  12  is in the stationary state and the vehicle movement state fails to indicate intent to move the vehicle  12 . 
         [0022]    As can be appreciated from the above, the vehicle movement state indicates intent to maintain the vehicle stationary when the transmission state is a non-motive state and the brake state is a brake undepressed or released state. It should be noted that the terms undepressed or released can be used interchangeably. When the controller  14  determines in step  120  that, for example, the brake is moved into the brake depressed state (time t 2  in  FIG. 3 ), the controller  14  determines that the vehicle movement state indicates intent to move the vehicle  12  from the stationary state. In this example, the vehicle movement state indicates intent to move the vehicle  12  when the transmission state is a non-motive state, such as a vehicle park position or a vehicle neutral position, and the brake state is a brake depressed state. Accordingly, processing continues to step  130  where the controller  14  controls the VSP module  16  to emanate an audible alert from the audio component  30  at a first sound pressure level while the vehicle  12  is in the stationary state. 
         [0023]    The controller  14  controls the VSP module  16  to continue emanating the audible alert from the audio component  30  while the controller  14  monitors the signals from the transmission state detector  26  in step  140 . When the controller  14  determines based on the signals from the transmission state detector  26  that the transmission has not yet been moved to a motive state, the processing returns to step  120  to confirm that the vehicle movement state still indicates an intent to move. If the vehicle movement state still indicates an intent to move, the controller  14  controls the VSP module  16  to continue emanating the audible alert from the audio component  30  in step  130  and proceeds to step  140 . If the vehicle movement state fails to indicate intent to move, the controller  14  controls the VSP module  16  to refrain from emanating the audible alert from the audio component  30  in step  110  and repeats as discussed above. 
         [0024]    However, when the controller  14  determines based on the signals from the transmission state detector  26  that the transmission has been moved to a motive state (time t 3  in  FIG. 3 ), the processing continues to step  150 . It should be noted that when the transmission state is a motive state and the brake state is any brake state, the vehicle movement state indicates intent to move the vehicle. 
         [0025]    In step  150 , the controller  14  determines whether the motive state is a vehicle forward movement position (e.g., a drive transmission position) or a vehicle reverse movement position (i.e., a reverse transmission position). As mentioned above, the transmission can be an automatic or manual transmission. Thus, for a manual transmission, the forward movement position could be any of the forward gear positions such as first gear, second gear, third gear and so on. If the controller  14  determines that the motive state is a vehicle forward movement position, the processing continues to step  160  where the controller  14  monitors the accelerator position sensor  20 , the speed sensor  22 , or both, to determine whether the vehicle  12  has begun to move. During this time, the controller  14  can control the VSP module  16  to continue to emanate the sound from the audio component  30  at the first sound pressure level while the transmission state is the motive state (e.g., forward motive state) and the brake state is the brake depressed state. 
         [0026]    When the controller  14  determines in step  160  that the vehicle  12  is not moving, the controller  14  determines in step  170  whether the brake state is a brake released state. If the brake state is not a brake released state, the processing will return to step  140  as discussed above, and the controller  14  can control the VSP module  16  to continue to emanate the sound from the audio component  30  at the first sound pressure level. Assuming that the gear remains in the forward motive gear and the vehicle  12  is not moving, the processing will proceed through steps  140 ,  150  and  160  as discussed above. The controller  14  will continue to monitor the brake state and repeat the steps as discussed above. When the controller  14  determines in step  170  that the brake is in a brake released state, the processing continues to step  180 . 
         [0027]    In step  180 , the controller  14  determines based on signals from the accelerator position sensor  20  whether the accelerator is in a depressed state. If the accelerator is not in a depressed state, the processing returns to step  170  and repeats as discussed above. That is, as long as the brake is in the brake released state, the processing will continue to step  180 . 
         [0028]    When the controller  14  determines in step  180  that the accelerator is in a depressed state and thus, the vehicle  12  will begin to move (time t 4  in  FIG. 3 ), the controller  14  controls the VSP module  16  to emanate a take off sound from the audio component  30  in step  190 . For example, the controller  14  can control the VSP module  16  to emanate the take off sound at a second sound pressure level that is greater than the first sound pressure level upon first detecting that the brake state changes from the brake depressed state to the brake released state and then detecting that the accelerator state changes from a released state to a depressed state while the transmission state is the motive state and the vehicle  12  is in the stationary state (time t 4  in  FIG. 3 ). 
         [0029]    After emitting the take off sound at the second sound pressure level for a predetermined period of time from when the accelerator state changes from the released state to the depressed state (time t 4  in  FIG. 3 ), the controller  14  can control the VSP module  16  to decrease the sound. That is, in step  190 , the controller  14  can control the VSP module  16  to decrease the sound from the second sound pressure level to a decreased third sound pressure level that is below the second sound pressure level (time t 5  in  FIG. 3 ). The third sound pressure level can be equal to or greater than the first sound pressure level. The processing then returns to step  160 . 
         [0030]    Since the accelerator was or still is in the depressed state, the controller  14  will determine in step  160  that the vehicle  12  is moving. Thus, the processing will continue to step  200 . In step  200 , the controller  14  can monitor the signals from the accelerator position sensor  20 , the signals from the speed sensor  22 , or both, to determine whether the vehicle  12  is being accelerated. If the controller  14  determines that the vehicle  12  is being accelerated, the processing continues to step  210 . In step  210 , the controller  14  determines based on the signals from the speed sensor  22  whether the speed of the vehicle  12  is not above a predetermined speed (a first prescribed speed). As long as the speed of the vehicle  12  is at or below a predetermined speed, the processing continues to step  220  and the controller  14  controls the VSP module  16  to increase the sound pressure level in relation to the acceleration (or speed) of the vehicle  12 . Therefore, as shown in  FIG. 3 , the sound pressure level increases to a fourth sound pressure level while the vehicle  12  is being accelerated. The fourth sound pressure level can be less than the second sound pressure level as shown, or can be any suitable level. 
         [0031]    Thus,  FIG. 3  illustrates operations that can occur when the vehicle  12  is traveling at a low speed, such as below 30 km/hr or any other suitable speed. In addition, the controller  14  can control the VSP module  16  to change a pitch of the sound in accordance with at least one of the position of the accelerator and the speed of the vehicle  12 . Furthermore, the controller  14  can control the VSP module  16  to pulse the sound as discussed above with regard to  FIG. 6  at any time that the sound is being emitted, and can vary the cadence of the pulsing as desired, such as in accordance with acceleration (or speed) of the vehicle  12 . 
         [0032]    When the controller determines in step  200  that the vehicle  12  is no longer being accelerated and is not moving at a speed above the first predetermined speed (time t 6  in  FIG. 3 ), the controller  14  can control the VSP module  16  to continue to emit the sound at the fourth sound pressure level. That is, if the controller  14  determines in step  200  that the vehicle  12  is not being accelerated, the controller  14  can monitor signals from the brake state detector  24 , signals from the speed sensor  22 , or both, in step  240  to determine whether the vehicle  12  is decelerating. If the controller  14  determines in step  240  that the vehicle  12  is not decelerating, the controller  14  can proceed to step  250  to determine whether the vehicle  12  is stopped based on, for example, the signals from the vehicle speed sensor  22 . If the vehicle  12  is not stopped, the processing can return to step  160  and repeat as discussed above. 
         [0033]    Therefore, although not shown explicitly in  FIG. 3 , the controller  14  can continue to monitor the position of the accelerator, the signals from the speed sensor  22 , or both, in step  200  to determine whether the vehicle  12  is again accelerated. If the vehicle  12  is again being accelerated, the processing can return to step  210  to determine whether the vehicle  12  is not traveling above the predetermined speed. If the vehicle  12  is still not traveling above the predetermined speed, the processing continues to step  220  and the controller  14  can control the VSP module  16  to increase the pressure level of the emitted sound in relation to the acceleration of the vehicle  12 . 
         [0034]    The controller  14  also continues to monitor whether the vehicle  12  is being decelerated. That is, if the controller  14  determines in step  200  that the vehicle  12  is not being accelerated, the controller  14  can monitor signals from the brake state detector  24 , signals from the speed sensor  22 , or both, in step  240 . If the controller  14  determines in step  240  that the vehicle  12  is decelerating, the controller  14  can determine in step  260  whether the speed of the vehicle  12  is below a second prescribed speed. Presumably, for this example where the vehicle  12  is traveling at a low speed, such as below 30 km/hr or any other suitable speed, the speed of the vehicle  12  will be below the second prescribed speed. The second prescribed speed can be equal to or about equal to the first prescribed speed (e.g., 30 km/hr, 25 km/hr or any other suitable speed). 
         [0035]    Accordingly, if the controller  14  determines in step  260  that the vehicle  12  is travelling below the second prescribed speed, the processing continues to step  270 . In step  270 , the controller  14  will control the VSP module  16  to gradually decrease the pressure level of the emitted sound from the fourth sound pressure level (time t 7  in  FIG. 3 ). 
         [0036]    The controller  14  then determines in step  250  whether the vehicle  12  is stopped based on, for example, the signals from the vehicle speed sensor  22 . As discussed above, if the vehicle  12  is not stopped, the processing can return to step  160 . Assuming that the vehicle  12  is moving (step  160 ), the vehicle  12  is not accelerating (step  200 ), the vehicle  12  is decelerating (step  240 ) and the speed of the vehicle  12  is below the second prescribed speed (step  260 ), the controller  14  can control the VSP module  16  to continue to decrease the pressure level of the emitted sound from the fourth sound pressure level (or increased pressure level) to the first sound pressure level or any other suitable pressure level in step  270 . The processing then can repeat as discussed above as long as the vehicle  12  is not stopped. 
         [0037]    When the controller  14  determines in step  250  that the vehicle  12  is stopped (time t 8  in  FIG. 3 ), the processing returns to step  120  as discussed above. Thus, in step  120 , the controller  14  will determine whether the vehicle movement state indicates intent to move the vehicle  12  as discussed above. For example, the controller  14  will monitor signals from the brake state detector  24  and the transmission state detector  26  to determine whether the transmission has been moved to a non-motive state and the brake is in the depressed state, or the transmission remains in a motive state. If the controller  14  determines in step  120  that, for example, the transmission has not been moved to a non-motive state such as park or neutral (time t 9  in  FIG. 3 ) and the brake is still in the depressed state, or the transmission remains in a motive state, the controller  14  will determine that the vehicle movement state still indicates intent to move the vehicle  12 . Accordingly, the controller  14  will control the VSP module  16  to continue to emit sound from the audio component  30  at the first sound pressure level in step  130 . If the controller  14  determines in step  140  that the transmission is still in the motive gear, the processing proceeds to step  150  and repeats as discussed above. 
         [0038]    Furthermore, when the controller  14  determines in step  140  that the transmission is in the non-motive state, the controller  14  will determine in step  120  whether the vehicle movement state still indicates intent to move the vehicle  12  in the manner as discussed above. However, when the controller  14  determines in step  140  that the transmission is in the non-motive state and then determines in step  120  the brake is in the released state, the controller  14  will thus determine in step  120  that the vehicle movement state does not indicate intent to move the vehicle  12 . Therefore, the controller  14  will control the VSP module  16  in step  110  to discontinue emitting the sound (time t 10  in  FIG. 3 ). In other words, the controller  14  controls the VSP module  16  to cease emanating the sound when the vehicle returns to the stationary state after moving, the transmission state enters a non-motive state and the brake state enters a released state, in which event the vehicle movement state indicates intent to maintain the vehicle  12  stationary. 
         [0039]    The process then repeats as discussed above. Naturally, if the vehicle  12  is turned off, the process repeats at step  100  when the vehicle  12  is turned on again. 
         [0040]    Also, instead of the controller  14  controlling the VSP module  16  in step  220  to increase the sound pressure level, the controller  14  can instead control the VSP module  16  to maintain the sound pressure level at the third sound pressure level as shown in broken line in  FIG. 3 , or at any other suitable sound pressure level, during vehicle acceleration as long as the speed of the vehicle  12  is at or below a predetermined speed. As stated above, the third sound pressure level can be at or above the first sound pressure level, but is below the second sound pressure level of the take off sound. The processing otherwise is performed as described above with regard to  FIG. 3 . Thus, when the processing continues to step  270 , the controller  14  controls the VSP module  16  to gradually decrease the pressure level of the emitted sound from the third sound pressure level to the first sound pressure level (similar to time t 7  in  FIG. 3 ). Naturally, if the third pressure level is the same as the first pressure level, no such decrease needs to be performed, and the processing can continue as discussed above with regard to  FIG. 3 . 
         [0041]      FIG. 4  is identical to  FIG. 3 , except that  FIG. 4  illustrates an example of operations that can be performed when the controller  14  determines in step  120  that the vehicle movement state does not indicate intent to move the vehicle  12  when the vehicle  12  comes to a stop at time t 8 . That is, in step  140  of the flowchart in  FIGS. 2A and 2B , the controller  14  detects based on signals from the transmission state detector  26  that the transmission has been moved to a non-motive state such as park or neutral at or proximate to the time that the vehicle  12  has come to a stop. The controller  14  also detects in step  120  based on signals from the brake state detector  24  that the brake is in the released state at or proximate to the time that the vehicle  12  has come to a stop and the transmission has been moved to the non-motive state. 
         [0042]    Accordingly, as shown in  FIG. 4 , the controller  14  will control the VSP module  16  in step  100  to discontinue emitting the sound at or proximate to time t 8  in  FIG. 4 . The processing then repeats as discussed above. Therefore, the controller  14  controls the VSP module  16  to refrain from emanating the sound (an audible alert) from the audio component  30  in step  110 . However, once the controller  14  determines in step  120  that the vehicle movement state indicates intent to move the vehicle  12 , the controller  14  controls the VSP module  16  to emanate the sound at the first sound pressure level (time t 9  in  FIG. 4 ) and performs the operations as discussed above. Accordingly, the times indicated at t 10  and t 11  in  FIG. 4  correspond to times t 2  and t 3 , respectively, as shown in  FIGS. 3 and 4 . 
         [0043]    Furthermore, as with the operations in  FIG. 3 , the controller  14  can control the VSP module  16  to maintain the sound pressure level at the third sound pressure level as shown in broken line in  FIG. 4 , or at any other suitable sound pressure level, during vehicle acceleration as long as the speed of the vehicle  12  is at or below a predetermined speed. The processing otherwise is performed as described above with regard to  FIG. 4 . Thus, when the processing continues to step  270 , the controller  14  controls the VSP module  16  to gradually decrease the pressure level of the emitted sound from the third sound pressure level to the first sound pressure level (similar to time t 7  in  FIG. 4 ). Naturally, if the third pressure level is the same as the first pressure level, no such decrease needs to be performed, and the processing can continue as discussed above with regard to  FIG. 4 . 
         [0044]    As discussed above with regard to step  210  shown in the flowchart of  FIGS. 2A and 2B , the controller  14  determines in step  210  whether the speed of the vehicle  12  is below the first prescribed speed.  FIG. 5  illustrates an exemplary graph of operations that the controller  14  can perform when the speed of the vehicle  12  reaches the first prescribed speed. The graph shown in  FIG. 5  from times t 0  through t 6  generally corresponds to the graph shown in  FIG. 3  from times t 0  through t 6 . However, in  FIG. 5 , time t 6  indicates the sound pressure level when the vehicle  12  reaches the first prescribed speed. 
         [0045]    As shown in the flowchart of  FIGS. 2A and 2B , when the controller  14  determines in step  210  that the speed of the vehicle  12  is above the first prescribed speed, the processing proceeds to step  230 . In this example, the first prescribed speed can be 30 km/hr or any other suitable speed as discussed above. That is, as understood in the art, when the vehicle  12  is traveling at or above 25 km/hr, the noise naturally produced by the vehicle  12 , such as road noise and so on, is sufficient enough to be detected by pedestrians, so the VSP sound is no longer needed at those speeds. 
         [0046]    In step  230 , the controller  14  controls the VSP module  16  to gradually decrease or fade out the sound pressure level of the emitted sound until time t 7  shown in  FIG. 5  when the VSP module  16  ceases to emit the sound. The processing then returns to step  160  and repeats as discussed above. When the controller  14  determines in step  200  that the vehicle  12  is not accelerating, the processing continues to step  240  where the controller  14  determines whether the vehicle  12  is decelerating. If the vehicle  12  is decelerating, the processing continues to step  260  where the controller  14  determines whether the vehicle  12  continues to travel at or above the second prescribed speed. In this example, the second prescribed speed can be 25 km/hr or slightly below the first prescribed speed as discussed above. Naturally, the first and second prescribed speeds can be equal to each other or any suitable speeds. While the vehicle  12  is traveling at or above the second prescribed speed, the controller  14  controls the VSP module  16  in step  230  to continue to refrain from emitting the sound. 
         [0047]    As further shown in the example of  FIG. 5 , the accelerator is released and the brake is pressed and enters the brake depressed state at time t 8 . Therefore, the speed of the vehicle  12  begins to decrease. When the controller  14  determines in step  260  that the speed of the vehicle  12  has dropped to below the second prescribed speed (time t 9  in  FIG. 5 ), the controller  14  controls the VSP module  16  to gradually increase or fade in the sound pressure level of the emitted sound in step  270  until the VSP module  16  emits the sound at the fourth sound pressure level (or any other suitable sound pressure level) as discussed above. 
         [0048]    The processing thus continues to step  250  as discussed above. If the vehicle  12  is not stopped, the processing returns to step  160  and repeats. Since the controller  14  determines in step  240  that the vehicle  12  is decelerating because, for example, the brake is determined to be in the brake depressed state and thus the speed sensor  22  indicates that the vehicle speed is decreasing, the controller  14  controls the VSP module  16  to decrease the sound pressure level in step  270  (time t 10  in  FIG. 5 ) to the first sound pressure level until the vehicle  12  is determined to be stopped in step  250  as discussed above. When the controller  14  determines in step  250  that the vehicle  12  is stopped (time t 11  in  FIG. 5 ), the processing returns to step  120  where the controller  14  will determine whether the vehicle movement state indicates intent to move the vehicle  12  as discussed above. If the controller  14  determines in step  120  that the vehicle movement state still indicates intent to move the vehicle  12 , the controller  14  will control the VSP module  16  to continue to emit sound in step  130 . Furthermore, if the controller  14  determines in step  140  that the transmission has been moved to a non-motive state such as park or neutral (time t 12  in  FIG. 5 ) and the brake is still in the depressed state, the controller  14  will return to step  120  and determine that the vehicle movement state still indicates intent to move the vehicle  12 . Accordingly, the controller  14  will control the VSP module  16  to continue to emit sound from the audio component  30  at the first sound pressure level in step  130 . However, when the controller  14  determines in step  140  that the transmission is in the non-motive state and determines in step  120  that the brake is in the released state, the controller  14  will determine that the vehicle movement state does not indicate intent to move the vehicle  12 . Therefore, the controller  14  will control the VSP module  16  in step  110  to discontinue emitting the sound (time t 13  in  FIG. 5 ). 
         [0049]    The process then repeats as discussed above. Naturally, if the vehicle  12  is turned off, the process repeats at step  100  when the vehicle  12  is turned on again. 
         [0050]    Furthermore, as with the operations in  FIGS. 3 and 4 , the controller  14  can control the VSP module  16  to maintain the sound pressure level at the third sound pressure level as shown in broken line in  FIG. 5 , or at any other suitable sound pressure level, during vehicle acceleration as long as the speed of the vehicle  12  is at or below a predetermined speed (times t 5  through t 6 ). The processing otherwise is performed as described above with regard to  FIG. 5 . Thus, in step  230 , the controller  14  controls the VSP module  16  to gradually decrease or fade out the sound pressure level of the emitted sound from the third sound pressure level until time t 7  shown in  FIG. 5  when the VSP module  16  ceases to emit the sound. The processing then returns to step  160  and repeats as discussed above. When the controller  14  determines in step  260  that the speed of the vehicle  12  has dropped to below the second prescribed speed (time t 9  in  FIG. 5 ), the controller  14  controls the VSP module  16  to gradually increase or fade in the sound pressure level of the emitted sound in step  270  until the VSP module  16  emits and maintains the sound at the third sound pressure level (or any other suitable sound pressure level) as discussed above. When the processing continues to step  270 , the controller  14  controls the VSP module  16  to gradually decrease the pressure level of the emitted sound from the third sound pressure level to the first sound pressure level (similar to time t 10  in  FIG. 4 ). Naturally, if the third pressure level is the same as the first pressure level, no such decrease needs to be performed, and the processing can continue as discussed above with regard to  FIG. 5 . 
         [0051]    As discussed above with regard to  FIGS. 2A and 2B , the controller  14  determines in step  150  whether the motive state is a vehicle forward movement position (e.g., a drive transmission position or any forward motive gear position) or a vehicle reverse movement position (i.e., a reverse transmission position). If the controller  14  determines that the motive state is a vehicle reverse movement position, the processing continues to step  280  where the controller  14  controls the VSP module  16  to emit a reverse movement sound as shown in  FIG. 6 .  FIG. 6  illustrates an exemplary graph of operations that the controller  14  can perform when the motive state is a vehicle reverse movement position. The graph shown in  FIG. 6  from times t 0  through t 3  generally corresponds to the graph shown in  FIG. 3  from times t 0  through t 3 . However, in  FIG. 6 , time t 3  indicates the time that the controller  14  determines that the motive state is a vehicle reverse movement position. 
         [0052]    Accordingly, in step  280 , the controller  14  controls the VSP module  16  to emanate the sound, including pulsing the sound when the vehicle movement state indicates intent to move the vehicle  12  and the transmission state is a vehicle reverse movement position. The controller  14  can control the VSP module  16  to pulse the sound between zero and a second level, or between a level greater than zero and the second level. The second level can be greater than or equal to the first level, for example, or the fourth level shown in  FIG. 6  which is discussed below. Also, while the transmission is in the vehicle reverse movement position, the controller  14  can continue to detect signals from accelerator position sensor  20 , the speed sensor  22 , the brake state detector  24  and the transmission state detector  26 . Thus, when the controller  14  determines in step  290  that the vehicle  12  is still stationary, the controller  14  can control the VSP module  16  to continue to pulse the sound in step  280 . 
         [0053]    However, when the brake is in the brake released state and the controller  14  determines, for example, from the speed sensor  22  or the accelerator position sensor  20  that the accelerator is in the accelerator depressed state and the vehicle  12  is thus moving (time t 4  in  FIG. 6 ), the processing can continue to step  200  and repeat as discussed above. In other words, although not shown explicitly in  FIG. 6 , the controller  14  can change the peak sound pressure (volume) of the emitted sound based on the acceleration (or speed) of the vehicle  12  in the reverse direction in a manner similar to that described above with regard to the forward movement of the vehicle  12 . The controller  14  can still control the VSP module  16  to continue to pulse the sound even during this increase and decrease in peak sound pressure based on acceleration and deceleration of the vehicle  12 . Naturally, the controller  14  can change the rate of pulsing (e.g., increase or decrease the rate of pulsing or cadence rate) when the vehicle  12  is being accelerated or decelerated in the reverse direction. Of course, the controller  14  can alternatively control the VSP module  16  to continue to pulse the sound between the same levels (volumes) and at the same pitch and cadence regardless of the acceleration and deceleration of the vehicle  12  as shown in  FIG. 6 . 
         [0054]    While repeating the operations shown in  FIGS. 2A and 2B  in a manner similar to that for the forward movement of the vehicle  12  as discussed above, the controller  14  can determine that the brake is in the brake depressed state (time t 5  in  FIG. 6 ) and the vehicle  12  is stopped (time t 6  in  FIG. 6 ). The controller  14  can thus determine whether the transmission position has changed in steps  140  and  150  as discussed above. If the transmission position has not changed from the reverse vehicle position, the controller  14  will control the VSP module  16  to continue to pulse the sound as discussed above. However, if the controller  14  determines in step  150  that the transmission position has changed to, for example, a vehicle forward movement position, the processing will proceed to step  160  and repeat as discussed above. As indicated, times t 6 , t 7 , t 8  and t 9  in  FIG. 6  generally correspond to times t 3 , t 4 , t 5  and t 6 , respectively, in  FIG. 3 . Thus, the operations performed at times t 6 , t 7 , t 8  and t 9  in  FIG. 6  generally correspond to the operations performed at times t 3 , t 4 , t 5  and t 6 , respectively, in  FIG. 3  as discussed above. Also, the third, fourth and fifth sound levels shown in  FIG. 6  generally correspond with the second, third and fourth sound levels, respectively, shown in  FIG. 3 . Naturally, as discussed above with regard to  FIGS. 3-5 , the controller  14  can control the VSP module  16  to maintain the sound pressure level at the fourth sound pressure level as shown in broken line in  FIG. 6 , or at any other suitable sound pressure level, during vehicle acceleration as long as the speed of the vehicle  12  is at or below a predetermined speed. 
       General Interpretation Of Terms 
       [0055]    In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Also, the term “detect” as used herein to describe an operation or function carried out by a component, a section, a device or the like includes a component, a section, a device or the like that does not require physical detection, but rather includes determining, measuring, modeling, predicting or computing or the like to carry out the operation or function. The term “configured” as used herein to describe a component, section or part of a device includes hardware and/or software that is constructed and/or programmed to carry out the desired function. The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. 
         [0056]    While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them. The functions of one element can be performed by two, and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

Technology Classification (CPC): 1