Abstract:
A collision detection and warning system for an automobile having left and right audio speakers and left and right turn signals includes at least four sensors and a control module. The sensors may be mounted on exterior surfaces of the automobile, such as on sides of the front and back bumpers, and are connected to the control module and the automobile&#39;s electrical system. The sensors are mounted in mounting assemblies and can be angularly oriented. Each corresponding front and back pair of sensors may detect an obstacle in the driver&#39;s “blind spot” when oriented in an appropriate beam splitting arrangement. Upon obstacle detection and actuation of a respective turn signal, the control system sends an alarm tone to the automobile&#39;s audio speaker on the side of the car nearest the danger and/or activates a respective alarm light to indicate the direction of danger.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to systems for detecting obstacles and avoiding collisions. In particular, the present invention relates to a collision detection and warning system for an automobile that uses audible alerts to warn a driver of obstacles in the driver&#39;s “blindspots” at the rear and sides of the vehicle.  
         [0002]     It is often difficult to change lanes while driving because the driver&#39;s blindspots at the rear and sides of the vehicle cannot be seen with either the rearview or side mirrors effectively. The rear looking neck movements are difficult for much of today&#39;s population, including the elderly, and the movements distract all drivers from looking ahead. A device that would make changing lanes easier and less dangerous would be widely welcomed.  
         [0003]     Collision detection systems have been proposed on high-end cars in today&#39;s market. While the technology to achieve collision avoidance, problems with cost and convenience have kept this innovation off most new vehicles and virtually all older vehicles.  
         [0004]     Some current systems use either a single transmitter located on the vehicle, such as in U.S. Pat. No. 4,450,430, or a single transmitter located at each side of the vehicle, such as in U.S. Pat. No. 4,028,662 and U.S. Pat. No. 5,339,075, to em it sound, light, or electromagnetic radiation waves at a target area. Some systems, such as in U.S. Pat. No. 5,583,495, suggest either a single transmitter or a transmitter on each side of the vehicle. If an object is in the target area, that object will reflect the waves. These systems then detect the presence of the reflected waves to determine if an object is in the target area, and some of the systems can detect the object&#39;s speed relative to the driver&#39;s vehicle. A warning signal is transmitted to the driver when a danger is sensed. Nevertheless, many of these systems have had difficulties effectively limiting the target area to distances that pose a danger to the driver. Without effectively limiting the target area, systems detect that a danger is posed to the driver when no such danger exists; this can be referred to as a false alarm or a false positive.  
         [0005]     Other current systems use scanning transmitters and receivers, such as in U.S. Pat. No. 6,657,581, to obtain more information about the location of objects in the target areas and determine whether an object poses a threat to the driver. These transmitters and receivers act like those mentioned above and poorly limit the target area. However, the multiple readings help to overcome this shortcoming and provide a way to better determine which objects may be dangerous to the driver. U.S. Pat. No. 5,767,793 uses particular configurations of antenna arrays while scanning in order to better limit the target area and eliminate false positives.  
         [0006]     The systems in U.S. Pat. No. 6,281,786 and U.S. Pat. No. 6,606,027 use a plurality of sensors to create more target areas and obtain more information. This additional information helps compensate for the general inability to closely limit the target area.  
         [0007]     Still other current systems utilize complex circuitry and computer processing to determine the distance of an object from the transmitter, such as in U.S. Pat. No. 5,235,316.  
         [0008]     Therefore, it is desirable to have a collision detection and warning system for an automobile that can detect objects in the driver&#39;s blindspots or other target areas, is suitable for both new car manufacture and retrofitting existing vehicles, minimizes false alarms, effectively notifies the driver of impending danger, complies with regulations concerning transmitters, and is relatively inexpensive.  
       SUMMARY OF THE INVENTION  
       [0009]     A collision detection and warning system according to the present invention is suitable for use with an automobile of a type having a multi-speaker audio system and conventional turn signal controls. The system preferably includes four sensor assemblies and a control unit electrically connected to the audio system. A left alarm light, a right alarm light, and a mode switch may also be included. Each sensor assembly includes a sensor, an outer mounting plate, an inner mounting plate, a circuit board, and appropriate wiring.  
         [0010]     Each sensor connects to a circuit board that connects to the control module and the automobile&#39;s electrical system. The control module connects to the automobile&#39;s electrical system to detect the activation of the left and right turn signals, and an interface electrically connects the control module to the automobile&#39;s left and right audio speakers. A mode switch and left and right alarm lights are installed inside the automobile, and each connects to the control module. The four sensor assemblies attach to the sides of the front and rear bumpers, respectively. While the sensors are preferably simple proximity sensors, other sensors could also be used, such as radar, infrared, laser, and ultrasonic sensors, for example. High pass filters may be employed to eliminate signals from low frequency reflections, thus minimizing false positives from stationary objects.  
         [0011]     In use, each sensor transmits “pings” of sound or EM radiation and receives waves that are reflected back. When a sensor receives a reflected signal, a signal is sent to the control module. The control module alternates between a left blindspot checking routine and a right blindspot checking routine, both of which employ beam splitting to minimize false warnings. When an object is detected in the blindspot and the respective automobile turn signal is activated, the control system sends an alarm tone to the automobile&#39;s audio speaker on the side of the car nearest the danger and/or activates the respective alarm light to indicate the direction of danger.  
         [0012]     Therefore, a general object of this invention is to provide a collision detection and warning system for an automobile that can detect objects in the driver&#39;s blindspots or other target areas.  
         [0013]     Another object of this invention is to provide a collision detection and warning system for an automobile, as aforesaid, that effectively notifies the driver of impending danger.  
         [0014]     Still another object of this invention is to provide a collision detection and warning system for an automobile, as aforesaid, that minimizes false alarms.  
         [0015]     Yet another object of this invention is to provide a collision detection and warning system for an automobile, as aforesaid, that is suitable for both new car manufacture and retrofitting existing vehicles.  
         [0016]     A further object of this invention is to provide a collision detection and warning system for an automobile, as aforesaid, that complies with regulations concerning transmitters.  
         [0017]     A still further object of this invention is to provide a collision detection and warning system for an automobile, as aforesaid, that is relatively inexpensive.  
         [0018]     Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, embodiments of this invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]      FIG. 1  is a top view of an automobile equipped with a collision detection and warning system according to one embodiment of the present invention;  
         [0020]      FIG. 2  is a front perspective view of a sensor assembly according to the collision detection and warning system mounted on a bumper;  
         [0021]      FIG. 3  is an exploded perspective view of the sensor assembly as in  FIG. 2  and includes a bumper;  
         [0022]      FIG. 4  is a flow chart showing the operation of the left blindspot checking routine;  
         [0023]      FIG. 5  is a flow chart showing the operation of the right blindspot checking routine;  
         [0024]      FIG. 6  is a block diagram showing the components of the collision detection and warning system; and  
         [0025]      FIG. 7  is a block diagram showing the components of a collision detection and warning system according to another embodiment of the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]     A collision detection and warning system for an automobile according to the present invention will now be described in detail with reference to  FIGS. 1 through 7  of the accompanying drawings. More particularly, a collision detection and warning system  100  according to a now preferred embodiment includes four sensor assemblies  110  and a control module  120 . As to be described below in more details, the collision detection and warning system  100  may be electrically connected to a left car audio speaker  132 , a right car audio speaker  137 , a left automobile turn signal  140 , and a right automobile turn signal  145 . Accordingly, the system  100  may be retrofitted onto older existing automobiles. In addition, the system  100  may include a left alarm light  130 , a right alarm light  135 , and a mode switch  150  ( FIG. 6 ).  
         [0027]     Each of the four sensor assemblies  110  includes a sensor  160  and a sensor mounting assembly  161 . Each sensor mounting assembly  161  includes an outer mounting plate  162 , an inner mounting plate  163  with a ball and socket configuration, a circuit board  164 , a signal wire  165 , a positive wire  166 , and a negative wire  167 . One sensor assembly  110  is shown in  FIGS. 2 and 3 . The sensor  160  fits in the inner mounting plate  163  and is connected to the circuit board  164 . The inner mounting plate  163  is placed on an interior surface of an automobile, and the outer mounting plate  162  is placed on an exterior surface of the automobile and connected to the inner mounting plate  163 , thus clamping the respective sensor assembly  110  to the automobile. The positive and negative wires  166 ,  167  connect the circuit board  164  to the automobile&#39;s electrical system or an alternate power source, and the signal wire  165  transmits information from the circuit board  164  to the control module  120 . The sensor  160  in the first sensor assembly  110  can be referred to as the first sensor  170 , the sensor  160  in the second sensor assembly  110  can be referred to as the second sensor  172 , the sensor  160  in the third sensor assembly  110  can be referred to as the third sensor  175 , and the sensor  160  in the fourth sensor assembly  110  can be referred to as the fourth sensor  177 .  
         [0028]     The control module  120  connects to the automobile&#39;s electrical system to detect the activation of the left and right turn signals  140 ,  145 , and an interface electrically connects the control module  120  to the automobile&#39;s left and right audio speakers  132 ,  137 . By patching into the automobile&#39;s audio system, additional speakers do not need to be installed; this allows the present invention to be easily and economically incorporated into both new and existing vehicles. The mode switch  150  and left and right alarm lights  130 ,  135  are installed inside the automobile, and each is connected to the control module  120 .  
         [0029]     To operate effectively, the collision detection and warning system  100  must sense the presence of an object in the driver&#39;s blindspot or other danger zone, make a judgment on the likelihood that this object presents a danger to the driver, and warn the driver to take evasive action. There are many types of sensors that can accomplish this goal. Most use the wave properties of sound, light, or other EM radiation (radar, infrared, etc.) to sense objects. For example, in proximity sensors, a “ping” of sound or EM radiation is sent out. These waves spread out from their source, losing intensity as they spread. If the waves strike an object, they are reflected back towards the source. A sensor can then receive the signal and indicate to the user that an obstacle is present. While the sensors  160  are preferably simple proximity sensors due to their inexpensive nature, other sensors would also be suitable, such as radar, infrared, laser, and ultrasonic sensors.  
         [0030]     Because waves spread out in all directions, it is difficult to tell from which direction the signal is reflected. By using multiple transmitters and sensors in a split beam arrangement, more information about the obstacle&#39;s position can be determined. For example, if only a left sensor detects an object, the system can conclude that it is somewhere to the left of the overlap region. Beam splitting is used by the present invention to get maximum resolution with the minimum sensor array complexity.  
         [0031]     Knowing an object is present is sometimes not enough. It may be important to the current invention to be able to tell the difference between stationary and moving objects, which are likely to be other vehicles. There are many ways to compute speed, two of which are numerical differentiation and Doppler shift measurement. These techniques can be employed with many types of media, including sound and EM radiation and can easily be incorporated into the current invention if so desired.  
         [0032]     In the preferred embodiment, the collision detection and warning system  100  focuses on the driver&#39;s blindspots to the side and rear of the vehicle, though other danger zones can of course be targeted. The first sensor assembly  110  is installed on the left side of the front bumper  2 , the second sensor assembly  110  is installed on the left side of the rear bumper, the third sensor assembly  110  is installed on the right side of the front bumper  2 , and the fourth sensor assembly  110  is installed on the right side of the rear bumper. The sensors  170 ,  175  in the front sensor assemblies  110  point generally rearward, and the sensors  172 ,  177  in the rear sensor assemblies  110  point generally sideways. The target areas A, B of the first and second sensors  170 ,  172  are shown in  FIG. 1 , along with an automobile in the driver&#39;s blindspot. To eliminate false alarms, it is important to only activate an alarm to the driver when the target areas A, B of the first and second sensors  170 ,  172  overlap and the driver is preparing to turn left or the target areas of the third and fourth sensors  175 ,  177  overlap and the driver is preparing to turn right. To determine if the driver plans to turn left or right, the control module  120  checks for the activation of the left and right turn signals  140 ,  145 .  
         [0033]     In use, each of the four sensors  160  transmits “pings” of sound or EM radiation and receives waves that are reflected back. When one of the four sensors  160  receives a reflected signal, a signal is sent to the control module  120  through a respective signal wire  165 . The control module  120  alternates between a left blindspot checking routine  121  and a right blindspot checking routine  122 . The processing steps of the left blindspot checking routine  121  are shown in the flowchart of  FIG. 4 , and the processing steps of the right blindspot checking routine  122  are shown in the flowchart of  FIG. 5 .  
         [0034]     In process step S 1  of the left blindspot checking routine  121 , the control module  120  determines whether the first sensor  170  detects an obstacle. If so, the control module  120  proceeds to step S 2 ; if not, the control module  120  proceeds to step S 3 , where the control module  120  alternates to the right blindspot checking routine  122 .  
         [0035]     The control module  120  determines in step S 2  whether the second sensor  172  detects an obstacle. If so, the control module  120  proceeds to step S 4 ; if not, the control module  120  proceeds to step S 3 , where the control module  120  alternates to the right blindspot checking routine  122 . If the second sensor  172  detects an obstacle in process step S 2 , an object is in the left blindspot.  
         [0036]     The control module  120  determines in step S 4  whether the left turn signal  140  is activated. If so, the control module  120  determines that the driver is moving left and there is an object in the left blindspot; the control module  120  proceeds to step S 5 . If not, the control module  120  proceeds to step S 3 , where the control module  120  alternates to the right blindspot checking routine  122 .  
         [0037]     In process step S 5 , the control module  120  sends an alarm tone to the left car audio speaker  132  and/or activates the left alarm light  130 , depending on whether the mode switch  150  is set to audio warning, visual warning, or audio and visual warning. The control module  120  then proceeds to step S 3 , where the control module  120  alternates to the right blindspot checking routine  122 .  
         [0038]     In process step S 11  of the right blindspot checking routine  122 , the control module  120  determines whether the third sensor  175  detects an obstacle. If so, the control module  120  proceeds to step S 12 ; if not, the control module  120  proceeds to step S 13 , where the control module  120  alternates to the left blindspot checking routine  121 .  
         [0039]     The control module  120  determines in step S 12  whether the fourth sensor  177  detects an obstacle. If so, the control module  120  proceeds to step S 14 ; if not, the control module  120  proceeds to step S 13 , where the control module  120  alternates to the left blindspot checking routine  121 . If the fourth sensor  177  detects an obstacle in process step S 12 , an object is in the right blindspot.  
         [0040]     The control module  120  determines in step S 14  whether the right turn signal  145  is activated. If so, the control module  120  determines that the driver is moving right and there is an object in the right blindspot; the control module  120  proceeds to step S 15 . If not, the control module  120  proceeds to step S 13 , where the control module  120  alternates to the left blindspot checking routine  121 .  
         [0041]     In process step S 15 , the control module  120  sends an alarm tone to the right car audio speaker  137  and/or activates the right alarm light  135 , depending on whether the mode switch  150  is set to audio warning, visual warning, or audio and visual warning. The control module  120  then proceeds to step S 13 , where the control module  120  alternates to the left blindspot checking routine  121 . It is understood, of course, that the mode switch  150  may be set to deactivate the system such as in heavy or congested traffic.  
         [0042]     It is also possible for the mode switch  150  to have an override option that would instruct the control module  120  to alert the driver of all obstacles detected by the first sensor  170 , regardless of whether the object is detected by the second sensor  172 , and all obstacles detected by the third sensor  175 , regardless of whether the object is detected by the fourth sensor  177 . This would give the driver notice of objects that do not immediately pose a threat, and in effect create more false alarms. However, some users may prefer this. This option is not shown in  FIG. 4  or  FIG. 5 .  
         [0043]     Clearly the driver must be given the fastest possible warning without diverting his or her attention from the road, and instead of drawing the driver&#39;s attention to the warning signal, the device should ideally draw attention to the danger. Of course, in a lane changing situation, the driver will know the direction from which the danger is likely to originate, but by broadcasting a tone from that direction, the instinctive desire to turn towards a loud noise and assess the situation is utilized. It may even be advisable to mimic the sound of a car horn, as this sound often elicits a quick response when changing lanes. By allowing the driver to choose through the mode switch  150  whether audio alerts, visual alerts, or both will be provided, the present invention accounts for personal preferences. The mode switch  150  may also be used to disable (turn off) and enable (turn on) the collision detection and warning system  100 . Conversely, it is possible to eliminate the mode switch  150  and the left and right alarm lights  130 ,  135  from the present invention and rely on audio alerts. This would make the collision detection and warning system  100  easier to retrofit onto existing vehicles.  
         [0044]     A collision detection and warning system  200  according to another embodiment of the present invention is shown in  FIG. 7  and includes a construction substantially similar to the construction previously described except as specifically noted below. More particularly, the collision detection and warning system  200  according to this embodiment includes two high pass filters  210  to create a simple and cost-effective version of Doppler radar and further eliminate false alarms. The logic of warning system  200  is substantially similar to the logic of the warning system  100  described previously and as represented in  FIGS. 4 and 5 . However, it should be understood that the signals from the first and third sensors  170 ,  175  have passed through the high pass filters  210 . The collision detection and warning system  200  as shown in  FIG. 7  does not include a mode switch  150  or a left or right alarm light  130 ,  135 . Nevertheless, these features are shown in  FIGS. 4 and 5  and can easily be included with the collision detection and warning system  200  if desired.  
         [0045]     If another car is moving at roughly the same speed as the vehicle equipped with either the collision detection and warning system  100  or the collision detection and warning system  200 , the respective system will receive echoes at approximately the same frequency as the original transmission. In contrast, reflections from stationary objects are stretched out to a lower frequency because the object is moving relative to the car. A high pass filter  210  is used with the first and third sensors  170 ,  175  in the collision detection and warning system  200  to eliminate low frequency reflections and help minimize false positives from stationary objects, such as road signs or barricades, which may otherwise result. A high pass filter  210  may also be used in connection with all of the sensors  160 .  
         [0046]     It is understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.