Abstract:
An energy absorption system comprises a vehicle bumper, an energy absorption member attached to the vehicle bumper, and a plurality of ribs having respective first ends that are hingedly attached to the energy absorption member. The ribs extend between the energy absorption member and the bumper. The ribs may be actuated based on the speed information from the onboard vehicle communication network.

Description:
BACKGROUND 
       [0001]    Requirements for protecting a vehicle front end may conflict for different crash scenarios. For example, low-speed damageability (LSD) and pedestrian protection requirements may differ. LSD requirements generally dictate that no or minimal damage occurs to various vehicle front end components, e.g., side rails, radiator supports, doors, fenders, hood, hinges, headlamps, etc., at low speeds, e.g., speeds below 15 kilometers per hour (KPH). Accordingly, LSD scenarios generally require that approximately 80 percent of impact energy from a collision be absorbed by a vehicle bumper at speeds of 15 KPH or less. In contrast, pedestrian protection requirements are generally designed to limit pedestrian leg injuries to certain knee shear and bending moment targets at relatively higher speeds, e.g., around 40 kilometers per hour. Accordingly, relative to one another, LSD scenarios generally require a stiff bumper system, whereas pedestrian protection scenarios generally require a softer bumper mechanism. Unfortunately, current vehicle bumper systems are not adaptable to meet these different requirements. There is a need for a vehicle bumper system that can adapt to the respective requirements of an LSD scenario and a pedestrian protection scenario. 
     
    
     
       DRAWINGS 
         [0002]      FIG. 1  is a perspective view of an adaptive energy absorber system. 
           [0003]      FIG. 2  is a perspective view of the adaptive energy absorber system of  FIG. 1 , with a vehicle front fascia and portion of the bumper removed. 
           [0004]      FIG. 3  is a perspective view of first example of the adaptive energy absorber system of  FIG. 1 , including an adaptive energy absorber and ribs deployed for a low-speed scenario. 
           [0005]      FIG. 4  is a perspective view of first example of the adaptive energy absorber system of  FIG. 1 , including an adaptive energy absorber and ribs deployed for a higher speed, e.g., pedestrian protection, scenario. 
           [0006]      FIG. 5  is a detail view illustrating a pulley and guide installed on the adaptive energy absorber of  FIG. 3 . 
           [0007]      FIG. 6  is a perspective view of a second example of an adaptive energy absorber including ribs deployed for a low speed scenario. 
           [0008]      FIG. 7  is a perspective view of the second example of an adaptive energy absorber including ribs deployed for a higher speed, e.g., pedestrian protection, scenario. 
           [0009]      FIG. 8  is a detailed view illustrating a linear actuator installed on the adaptive energy absorber of  FIGS. 5 and 6 . 
           [0010]      FIG. 9  is a perspective view of a portion of an adaptive energy absorber system illustrating an example of a connection between ribs and a pull rod. 
           [0011]      FIG. 10  is a block diagram of a vehicle bumper control system. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Disclosed herein and illustrated in the various figures is an adaptive energy absorber system  10  for a vehicle. As seen, for example, in  FIG. 1 , a vehicle front fascia  12 , which is shown for completeness and context, but which is not necessary to the energy absorber system  10 , may cover a bumper  14  and an energy absorber  16  affixed to the bumper  14 . The fascia  12  could be affixed to the energy absorber  16  with a low density foam or the like (not shown) to allow the fascia  12  to maintain a desired shape. The bumper  14  may be a conventional vehicle bumper, e.g., formed of steel or the like. The energy absorber  16  may be any one of a variety of materials, depending on energy absorption requirements, such as an elastomeric plastic, sheet metal, etc. The bumper  14  may further have affixed thereto side extensions  15 , as well as side members, e.g., crash cans,  20 . The bumper  14 , e.g., the crash cans  20  and/or side extensions  15 , may be attached to a vehicle front end (not shown) in a conventional manner. 
         [0013]    As seen in both  FIGS. 1 and 2 , the energy absorber  16  may be offset from the bumper  14  by a plurality of ribs  18 . The ribs  18  are generally formed of a plastic, and are hingedly attached at respective first ends to the energy absorber  16 , e.g., each rib  18  may be connected to the energy absorber  16  by a plastic hinge  30  as illustrated in  FIG. 5 . Further, although shown with no holes or openings, the ribs  18  could be provided with such to reduce weight and material costs, so long as the hinges  30  are provided between the ribs  18  and the energy absorber  16 , and so long as the ribs  18  have sufficient strength to move the energy absorber  16  as described herein. In any case, hinged movement of the ribs  18  in a longitudinal direction with respect to the bumper  14  and energy absorber  16 , i.e., movement of second ends of the ribs  18  that are located distally with respect to the hinges  30 , can be actuated as described herein to change energy absorption characteristics of the energy absorption system  10 . 
         [0014]    As best seen in  FIGS. 3 and 4 , a cable  22 , e.g., formed of twisted wire or the like, may be threaded through an opening in the energy absorber  16 , or, alternatively, through openings provided for the cable in each of the ribs  18 . First and second ends of the cable  22  may be attached, e.g., via a known mechanism such as a clamp or the like, to respective first and second ends of the pull bar  26 . The pull bar  26  is affixed to respective second ends of each of the ribs  18 . For example, the pull bar  26  may be welded, glued, adhered, etc. to the second ends of the ribs  18 . Alternatively, although not shown in the figures, note that , the pull bar could be segmented in two or more places, multiple pieces of the pull bar  26  being hingedly attached to one another. 
         [0015]    Alternatively or additionally, slots could be provided in the second ends of the ribs  18  to receive the pull bar  26 , which could be snapped into the slots and/or otherwise adhered or affixed. For example, as seen in  FIG. 9 , a plastic or metal pull rod  26  or  27  may be provided with a substantially circular cross-sections according to first and second diameters of various portions  34 ,  36 . For example, a first set of portions  34  of the a pull rod  26 ,  27  may have a reduced diameter compared to a second set of portions  36 . Further, first and of each rib  18 , i.e., an end that is attached to the pull rod  26  or  27 , may include an opening  38 . A size of the opening  38  may be according to a portion of a circle having a diameter equal to, or slightly smaller than, a diameter of the reduced portions  34  of the rod  26  or  27 . Accordingly, the portions  34  may be snapped into place in the openings  38  of respective ribs  18 , whereby friction will maintain the rod  26  or  27  in place with respect to each of the ribs  18 , i.e., maintain a fixed attachment of the rod  26  or  27  to the ribs  18 . 
         [0016]    As best seen in  FIG. 5 , movement of the cable  22  may be caused by actuation of a motorized pulley  24 , which may be affixed to the energy absorber  16 , e.g., using a screw, a bolt, etc. Further, one or more cable guides  28  may be provided to guide the cable  22  in a loop encompassing the opening in the energy absorber  16  and the opening in the pull bar  26 . For example, as seen in  FIGS. 3 and 4 , cable guides  28  may be provided at respective ends of the energy absorber  16 . Accordingly, actuating the motorized pulley to move the cable  22  thus results in longitudinal movement of the second ends of the ribs  18  with respect to the bumper  14  and energy absorber  16 , i.e., actuating the motorized pulley  24  to move the cable  22  results in changing a respective angle of each of the ribs  18  with respect to the energy absorber  16 . A specific angle or angles of the ribs  18  achieved by actuation of the pulley  24  may vary in various implementations and depends on materials used in various components of the system  10 , e.g., the energy absorber  16 , a shape of such components, as well as desired energy absorption characteristics of the system  10 . Actuation of the motorized pulley  24  is discussed further below with respect to  FIG. 10 . 
         [0017]      FIGS. 6-8  illustrate aspects of a second example of an adaptive energy absorber system  10 . In this second example, instead of a single pull bar  26 , the system  10  includes first and second pull bars  27 . Each of the pull bars  27  is generally affixed, e.g., in a manner described above with respect to the pull bar  26 , to respective second ends of some but not all of the ribs  18  that are hingedly attached to the energy absorber  16 . The pull bars  27  are generally not attached to a same rib  18 , i.e., are generally attached to completely different sets of the ribs  18 . For example, a first pull bar  27  may be attached to substantially half of the ribs  18 , and a second pull bar  27  may be attached to substantially half of the ribs  18 . 
         [0018]    Outer ends of each pull bar  27  are attached to respective link rods  32 , that are in turn attached to respective mechanisms to affect linear movement of the respective pull bars  27 , linear actuators  25 . An “outer end” of a pull bar  27  means a first end of the pull bar  27  that is proximate to an end of the energy absorber  16 , i.e., closer to an end of the energy absorber  16  than a second end of the pull bar  27 . The linear actuators  25  are mounted on or at respective ends of the energy absorber  16  in a known manner, e.g., via screws, bolts, etc. By moving the linear actuators  25  in a longitudinal direction with respect to the energy absorber  16  and the bumper  14 , second ends of the ribs  18 , i.e., ends not hingedly attached to the energy absorber  16 , can also be moved in the longitudinal direction. That is, the second ends of the ribs  18  are moved when the pull bar  27  is pushed or pulled by a linear actuator  25  via a link rod  32 . Accordingly, respective angles of first and second sets of ribs  18  with respect to the energy absorber  16  can be changed, thereby changing energy absorption characteristics of the system  10 . Note that respective linear actuators  25  can move respective pull bars  27  in respective first and second longitudinal directions, e.g., toward respective first and second ends of the energy absorber  16  as illustrated by  FIG. 7 . Further, other mechanisms could be used instead of the linear actuators  25 , e.g., a solenoid mechanism. 
         [0019]      FIG. 6  shows the ribs  18  deployed for a scenario such as an LSD scenario in which greater stiffness of the bumper system  10  is required, i.e., the bumper system  10  should be configured to absorb a greater amount of energy, leaving less energy to be absorbed by other components in a vehicle. Accordingly,  FIG. 7 , in contrast, shows the ribs  18  deployed for scenario such as a pedestrian protection scenario involving relatively higher vehicle speeds, in which the bumper system  10  should be configured to absorb less energy, thereby allowing more energy of an impact to be absorbed by other components in a vehicle. As can be seen in  FIG. 6 , the ribs  18  when deployed for the LSD scenario may be substantially perpendicular to the energy absorber  16 , or to a tangent at a longitudinal center of the energy absorber  16  where the energy absorber  16  is longitudinally curvilinear. In  FIG. 7 , on the other hand, the ribs  18 , e.g., when deployed for a pedestrian protection scenario, are angled with respect to the energy absorber  16  or tangent thereof, e.g., by 10 degrees or some other angle to provide a desired energy absorption characteristic of the system  10 . 
         [0020]      FIG. 10  is a block diagram of a vehicle bumper control system  100 . The system  100  includes a controller  105  communicatively coupled to one or more actuators  115 . The controller  105  generally includes a processor and a memory, the memory storing instructions executable by the processor. Further, the controller  105  may communicate on an in-vehicle network and/or communications mechanism, such as a controller area network (CAN) or the like. Accordingly, in addition to one or more actuators  115 , the controller  105  may be communicatively coupled to one or more speed sensors  110 . A speed sensor  110  may be any one of a number of known mechanisms for providing an indication of vehicle speed to the controller  105 , e.g., as a CAN communication or the like. The actuator  115  shown in  FIG. 9  is a generic representation of an actuator used to effect a change in an energy absorber system  10 , e.g., one of the actuators  24 ,  25  discussed above. 
         [0021]    A process executed according to instructions stored in the memory of the controller  105  could include a step of, when a vehicle is in motion, using data from one or more speed sensors  110  to determine whether to deploy the bumper system  10  according to a low-speed scenario or a high-speed scenario, e.g., an LSD scenario or a pedestrian protection scenario. For example, a low-speed scenario could be identified when a vehicle was traveling at a speed of 15 kilometers per hour or less, while a high-speed scenario could be identified for any higher speed than this. In any event, upon identifying a scenario, the controller  105  could send a signal, e.g., a CAN communication, to an actuator or actuators  115  to move ribs  18  to achieve a desired energy absorbing characteristic of the system  10 . Accordingly, in the event of an impact, the system  10  would provide appropriate energy absorbing characteristics for a speed of impact. 
         [0022]    As used herein, the adverb “substantially” modifying an adjective means that a shape, structure, measurement, etc. may deviate from an exact described geometry, distance, measurement, etc., because of imperfections in materials, machining, manufacturing, etc. 
         [0023]    In the drawings, the same reference numbers indicate the same elements. Further, some or all of these elements could be changed. Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. 
         [0024]    Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims. 
         [0025]    All terms used in the claims are intended to be given their ordinary meaning as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.