Abstract:
A collision detection unit mounts to a host vehicle. The collision detection unit includes a housing and a stop lamp associated with the housing and visible from outside the housing. A warning lamp is associated with the housing and is visible from outside the housing. A sensor is associated with the housing and is configured to detect an object.

Description:
TECHNICAL FIELD 
       [0001]    The present specification generally relates to vehicle warning systems and methods and, more specifically, to vehicle warning systems and methods for alerting vehicles of a potential collision when predetermined conditions are met. 
       BACKGROUND 
       [0002]    Motor vehicles may come equipped with one or more collision detecting systems, which may help predict and warn of a potential collision, for example, with another vehicle. Such collision systems may be “front end” collision detecting systems, which detect objects in front of the host vehicle or “rear-end” collision detecting systems, which detect objects behind the host vehicle. 
         [0003]    Some reports indicate that approximately 25 percent of all reported traffic accidents are rear-end crashes. It is desirable to reduce and/or mitigate such rear-end crashes. While it is generally known to locate a sensor, for example, at the rear bumper for detecting an object approaching the host vehicle, other collision detecting systems are desirable. 
       SUMMARY 
       [0004]    In one embodiment, a collision detection unit mounts to a host vehicle. The collision detection unit includes a housing and a stop lamp associated with the housing and visible from outside the housing. A warning lamp is associated with the housing and is visible from outside the housing. A sensor is associated with the housing and is configured to detect an object. 
         [0005]    In another embodiment, a vehicle includes a rear windshield and a collision detection unit mounted at the rear windshield. The collision detection unit includes a housing and a stop lamp mounted in the housing and visible from outside the vehicle. A warning lamp is mounted in the housing and visible from outside the vehicle. A sensor is mounted in the housing. The sensor is configured to detect an object located behind the vehicle. A processing unit is configured to activate the warning lamp based on input from the sensor. 
         [0006]    In yet another embodiment, a method of warning a following vehicle from a host vehicle of a potential collision is provided. The method includes detecting the following vehicle using a sensor; determining a speed between the following vehicle and the host vehicle using a processing unit; determining a distance between the following vehicle and the host vehicle using the processing unit; and warning the following vehicle if a threshold criteria is met by activating a warning lamp using the processing unit; wherein the sensor, processing unit and warning lamp are all mounted in a housing mounted to the host vehicle. 
         [0007]    These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which: 
           [0009]      FIG. 1  is a diagrammatic side view of a host vehicle including an embodiment of a collision detection system detecting a following vehicle; 
           [0010]      FIG. 2  is a perspective rear view of the host vehicle of  FIG. 1  including the collision detection system; 
           [0011]      FIG. 3  is a diagrammatic front view of an embodiment of an integrated rear-end collision detection unit for use in the collision detection system of  FIG. 1 ; 
           [0012]      FIG. 4  is a schematic illustration of the integrated rear-end collision detection system of  FIG. 3 ; and 
           [0013]      FIG. 5  is an embodiment of a process for warning a following vehicle of a potential collision using the integrated rear-end collision detection unit of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]      FIG. 1  generally depicts one embodiment of a host vehicle  10  including a collision detection system, generally referred to as element  12 . In the illustrated embodiment, the collision detection system  12  detects objects, such as vehicle  16 , located at a rear-end  14  of the host vehicle. Various embodiments of the collision detection system  12  and the operation of the collision detection system will be described in more detail herein. 
         [0015]    Referring to  FIGS. 1 and 2 , the host vehicle  10  includes the rear-end  14  including a first lamp set  18  located at a first lateral side  20  and a second lamp set  22  located at an opposite lateral side  24 . Any suitable configuration may be utilized for the lamp sets  18  and  22 , such as a tail lamp, a stop and tail lamp, a turn signal lamp, a back up lamp, etc. The lamp sets  18  and  22  may be a single unit type or multi-unit type. The lamp sets  18  and  22  may include cover lenses, back panels, light emitting devices, wires, sockets, connectors, reflectors, etc. 
         [0016]    Located above the lamp sets  18  and  22  and at a rear windshield  26  (e.g., above closed trunk lid  28 ) is an integrated rear-end collision detection unit  30 . In some embodiments, the integrated rear-end collision detection unit  30  may be located at about where a high mount stop lamp set is located. The integrated rear-end collision detection unit  30  may be mounted at the upper middle or lower middle of the rear windshield  26  or on the trunk lid  28 , among other locations. In the illustrated embodiment, the integrated rear-end collision detection unit  30  is mounted at the lower middle of the rear windshield  26 . The integrated rear-end collision detection unit  30  may be mounted behind (i.e., within the interior of the host vehicle  10 ), in front of (e.g., outside the interior of the host vehicle) or partially behind and in front of the rear windshield  26 . With the integrated rear-end collision detection unit  30  mounted at least partially behind (within the interior) the host vehicle  10 , the integrated rear-end collision detection unit may be mounted upon a rear dash surface  33  or on a roof  35  of the host vehicle. In the illustrated embodiment, only a rear portion of the integrated rear-end collision detection unit  30  is mounted behind the rear windshield  36  with a front portion being located outside the interior of the host vehicle  10 . 
         [0017]    Referring particularly to  FIG. 1 , the integrated rear-end collision detection unit  30  detects information regarding the positional relationship between the host vehicle  10  and a following vehicle  16  (or other object), such as relative speed, relative distance, orientation of the following vehicle with respect to the host vehicle, etc. In some embodiments, the integrated rear-end collision detection unit  30  may be connected to other vehicle systems, such as a steering angle sensor  34  for determining steering angle, a vehicle speed sensor  36  for determining vehicle speed, a headrest control apparatus  38  for controlling operation of an active headrest  40 , airbag control systems, etc. In some embodiments, the integrated collision detection unit  30  may be connected to an electronic control unit  42 , which in turn may be connected and control one or more of the various other vehicle systems based, at least in part, information received from the integrated rear-end collision detection unit. 
         [0018]    Referring now to  FIG. 3 , the integrated rear-end collision detection unit  30  may include a rearward facing side  44  that faces the following vehicle  16 , a frontward facing side  46  opposite the rearward facing side that faces toward the front of the host vehicle  10 , front-to-back sides  48  and  50  and top and bottom surfaces  52  and  54 . In some embodiments, any one or more of the rearward facing side  44 , frontward facing side  46 , front-to-back sides  48  and  50  and top and bottom surfaces  52  and  54  may include mounting structure (e.g., holes, brackets, slots, ribs, fasteners, etc.) for mounting the integrated rear-end collision detection unit  30  to corresponding mounting structure on the host vehicle  10 . 
         [0019]    A housing  56  provides a protective enclosure for housing components of the integrated rear-end collision detection unit  30 . The housing  56  may be formed of multiple housing parts that together form the protective enclosure. The housing  56  may be formed of any suitable material such as plastic and/or metal and formed by any suitable process or combination of processes such as stamping, machining, molding, drawing, extruding, etc. While the housing  56  is illustrated as being somewhat box-shaped, it may be any other suitable shape such as rounded and/or having more or less than the illustrated six sides. 
         [0020]    Located at the rearward facing side  44  are a first center high-mount stop lamp set  58  and a second center high-mount stop lamp set  60 . The center high-mount stop lamp sets  58  and  60  may be a single unit type or multi-unit type. The center high-mount stop lamp sets  58  and  60  may include cover lenses, back panels, light emitting devices, wires, sockets, connectors, reflectors, etc. The center high-mount stop lamp sets  58  and  60  may be red or orange in color and provide other drivers with an enhanced stop or brake warning signal to the following vehicle  16 . 
         [0021]    To an inside of the center high-mount stop lamp sets  58  and  60  are warning lamp sets  62  and  64 . The warning lamp sets  62  and  64  have a brightness when illuminated to warn the following vehicle  16  within a detection zone behind the host vehicle  10 . The warning lamp sets  62  and  64  may be a single unit type or multi-unit type. The warning lamp sets  62  and  64  may include cover lenses, back panels, light emitting devices, wires, sockets, connectors, reflectors, etc. The warning lamp sets  62  and  64  may be a color different than the center high-mount lamp sets  58  and  60 , such as white, to provide a warning other than a braking or stopping warning to the following vehicle  16 . 
         [0022]    To an inside of the warning lamp sets  62  and  64 , is a rearward sensor unit  66  that includes a rearward sensor  68  for detecting the following vehicle  16  (or other object). The rearward sensor  68  may use, for example, radio waves (e.g., millimeter waves), optical waves (e.g., laser waves) or ultra sound waves as detection waves for detecting the state of the following vehicle. In some embodiments, the rearward sensor  68  is a laser range sensor having a width and length of detection (i.e., the detection zone) that is suitable for detecting the following vehicle  16 , such as approximately one lane width (e.g., about 3.5 meters) and a distance of about 150 to about 500 meters, e.g., between about 150 to about 200 meters from the rear-end  14  of the host vehicle  10 . 
         [0023]      FIG. 4  shows, schematically, the integrated rear-end detection unit  30 . The housing  56  contains the center high-mount stop lamp sets  58  and  60 , the warning lamp sets  62  and  64  and the rearward sensor unit  66  that includes the rearward sensor  68 . A processing unit  70  receives detection signals  71  from the rearward sensor unit  66  and includes logic for determining relative speed, relative distance, orientation of the following vehicle with respect to the host vehicle, etc. The processing unit  70  also controls using control signals  73  the center high-mount stop lamp sets  58  and  60  and the warning lamp sets  62  and  64 . In some embodiments, the processing unit  70  may control the warning lamp sets  62  and  64  based on signals received from the rearward sensor unit  66  and may control the center high-mount stop lamp sets  58  and  60  based on braking information of the host vehicle, for example, received from the electronic control unit  42  ( FIG. 1 ). 
         [0024]    Referring to  FIG. 5 , an exemplary process  72  for warning a driver of the following vehicle  16  using the integrated rear-end collision detection unit  30  includes detecting the existence of and distance to the following vehicle  16  once the following vehicle enters the detection zone of the host vehicle  10  at step  74 . At step  76 , the processing unit  70  determines whether a change in distance occurs between the host vehicle  10  and the following vehicle  16 . If there is no change in distance between the host vehicle  10  and the following vehicle  16 , the processing unit  70  continues to check for a change in distance. If there is a change in distance between the host vehicle  10  and the following vehicle  16 , the processing unit  70  determines the speed difference between the host vehicle  10  and the following vehicle  16  at step  78 . At step  80 , the processing unit  70  determines whether the speed difference is a positive value (i.e., the host and following vehicles are moving closer together) or a negative value (i.e., the host and following vehicles are moving further apart). If the processing unit  70  determines that the speed difference is negative (or that the host and following vehicles are moving further apart), the processing unit continues to check for a change in distance until the following vehicle  16  falls outside the detection zone. If the processing unit  70  determines that the speed difference between the host vehicle  10  and the following vehicle  16  is positive (or that the host and following vehicles are moving closer together), the processing unit  70  uses the distance information and the speed information to determine whether a threshold criteria has been met at step  82 . If the threshold criteria has not been met, the processing unit  70  continues to check for a change in distance. If the threshold criteria has been met, the processing unit  70  activates the warning lamp sets  62  and  64  at step  84 . The threshold criteria determines whether to issue a warning to the following driver and may include speed and distance values and may be set based on, for example, vehicle characteristics, driver capability and driving conditions. The threshold criteria may be preset, for example, by the manufacturer, or it may be dynamic. For example, rain sensors, light sensors, etc. may be employed to adjust the threshold criteria depending on real-time driving conditions or the host driver may be able to adjust the threshold criteria. In some embodiments, the threshold criteria may be selected to provide at least about two seconds of reaction time for the following vehicle  16  to make an adjustment (e.g., decelerate or evasive maneuver) before a collision. 
         [0025]    In some embodiments, the warning lamp sets  62  and  64  may flash or blink when providing a warning signal. The warning lamp sets  62  and  64  may flash ON/OFF together or in sequence. In some embodiments, the processing unit  70  may control frequency of flashing, for example, depending on the magnitude of the relative speed difference and/or the relative distance between the host vehicle  10  and the following vehicle  16 . 
         [0026]    The above-described integrated rear-end collision detection unit  30  provides a self-contained package having the processing unit  70 , the center high-mount stop lamp sets  58  and  60 , the warning lamp sets  62  and  64  and the rearward sensor unit  66  including the rearward sensor  68  all integrated within the same housing  56 . Such an integration of component into the same housing  56  can provide increased flexibility as compared to having various components spread apart throughout the vehicle. Location of the rearward sensor unit  66  at a higher position above the trunk lid can reduce malfunction, for example, due to obstructions near the road as compared to lower mounted sensors (e.g., around the bumper). The integrated packaging can reduce data communication and processing load of the processing unit  70  because sensing, processing and activation are all executed by the integrated rear-end collision detection unit  30 . 
         [0027]    While warning lamp sets  62  and  64  are described above, other warning signals may be provided to the following vehicle  16  and/or to the host vehicle  10 . For example, an audible sound may be provided to warn the following vehicle  16  and/or the host vehicle  10 . In some embodiments, the integrated rear-end collision detection unit  30  may include a transmitter that can transmit a warning signal that can be detected by the following vehicle  16  and/or host vehicle  10 . Lights may be provided within the host vehicle  10  and/or following vehicle that illuminate based on a signal from the integrated rear-end collision detection unit  30 . In some embodiments, the integrated rear-end collision detection unit  30  may include a receiver, for example, to receive information from a global positioning satellite or other source, such as from the following vehicle  16 . 
         [0028]    It is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. 
         [0029]    While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.