Abstract:
A bracket for attaching and aligning a forward-looking radar (FLR) having a front face is disclosed according to one embodiment. The bracket includes a bracket frame having an attachment feature for attaching the FLR to the bracket frame. The bracket also includes a first mounting feature extending from the bracket frame for coupling the bracket face and the first mounting surface of the conveyance to define a first mounting surface angle. The bracket also includes a bracket member extending from the bracket frame. The bracket member includes an end portion disposed proximate to the bracket face and a distal end portion, which includes a second mounting feature for coupling the bracket member and the second mounting surface thereby defining a second mounting surface angle and aligning the FLR front face to an alignment angle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. Application Ser. No. 11/626,897, filed Jan. 25, 2007, which issued on Aug. 2, 2011 as U.S. Pat. No. 7,988,212, the disclosure of which is incorporated in its entirety by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     One aspect of the present invention generally relates to a vehicle mounting and alignment bracket for use in a radar application. 
     2. Background Art 
     Active safety systems for vehicles have been quickly growing in popularity in recent years. These systems typically sense a vehicle&#39;s external environment, determine a safety criticality level of current and near future events based on the sensed data, and actuate on-board vehicle systems to react accordingly. According to several proposals, the vehicle&#39;s external environment is sensed using a forward looking radar (FLR) unit. 
     Due to radar power limitations set by the Federal Communications Commission (FCC) and other international governing bodies, a radar is limited to a maximum threshold energy level. Given these limitations, the beam emitted from the FLR unit must be tight and narrow to maximize the range of the beam so that the FLR unit can sense at adequate distances from the vehicle. Therefore, the FLR unit, and hence the radar beam, is typically aligned with a relatively high degree of angular accuracy, such as vertical angular accuracy. 
     Mounting the FLR unit to a vehicle within the tolerable vertical angular accuracy limits can be challenging because vehicle mounting surfaces used to mount the FLR unit have relatively uncontrolled vertical angular accuracy. For example, the FLR unit can be mounted to the front surface of the vehicle front bumper. During vehicle assembly, the vehicle front bumper is attached to the end of the apron assembly through holes in the apron end and screws connected to the vehicle front bumper. The hole locations can vary significantly between apron ends, for example +/−3.0 millimeters, which may produce a significant variation in the vertical angular alignment of the front bumper mounting surface. If the FLR unit is mounted to this surface, then the use of expensive equipment and time consuming manual adjustment is often necessary to properly vertically align the front face of the FLR unit so that it can be used in active safety systems. 
     Manual adjustment has many problems. One of the problems is an ergonomics issue. The FLR unit is often located behind a removable fascia panel to minimize styling impact. The FLR unit is adjusted after the fascia panel is installed, thereby making it difficult to manually inspect the FLR unit, and even more difficult to make adjustments to the angular accuracy. These difficulties often translate into “blind” adjustments with poor ergonomic repeatability. 
     The alignment can be performed at a user-friendly “pit” station with an operator lowered to an appropriate height so that the operator has a clear view of the unit and relatively easy access to the unit. However, this is a relatively costly solution as the typical existing manufacturing facility pits were designed to allow access to the vehicle underside and are typically not long enough to allow access to the area at the front of the vehicle. 
     Moreover, the alignment process itself is relatively time consuming. One process requires the operator to hold an alignment gauge on the FLR unit, read computer feedback, and turn an adjustment screw in response to the computer feedback. This process requires a high level of attention from the operator until the adjustment is completed, preventing the operator from performing other assembly tasks during alignment. 
     SUMMARY 
     In at least one aspect of the present invention, a vehicle mounting and alignment bracket for use in forward looking radar FLR applications is disclosed. In one embodiment, the vehicle mounting bracket can be utilized to align an FLR unit during assembly of the bracket to the vehicle. In at least one embodiment, the assembly alignment step reduces the need for costly and inefficient post bracket assembly corrective manual adjustment. 
     The above and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description, taken in connection with the accompanying drawings which: 
         FIG. 1  is a perspective view of a vehicle including a forward looking radar (FLR) unit mounted onto the vehicle according to one embodiment of the present invention; 
         FIG. 2  is an exploded, fragmented, perspective view of a vehicle apron assembly and a mounting bracket for mounting an FLR unit onto the vehicle apron assembly according to one embodiment of the present invention; 
         FIG. 2   a  is a fragmented, perspective view of a controlled mounting surface according to one embodiment of the present invention; 
         FIG. 3  is a schematic, cross-sectional, side view illustrating vertical angle tolerances of a FLR unit according to an embodiment of the present invention; 
         FIG. 4  an exploded view of a mounting bracket and an FLR unit according to an embodiment of the present invention; 
         FIG. 5  is a bottom view of the bumper of the vehicle apron assembly depicted in  FIG. 2 ; 
         FIG. 6  is an exploded, perspective view of a bracket mounting feature according to one embodiment; 
         FIG. 7  is an exploded, perspective view of a bracket mounting feature according to another embodiment of the present invention; and 
         FIG. 8  is an exploded, perspective view of a bracket mounting feature according to yet another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. Therefore, specific functional details herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one of ordinary skill in the art to variously employ the present invention. 
     Turning to the drawings,  FIG. 1  depicts a perspective view of a vehicle  10  including a forward looking radar (FLR) unit  12  mounted to the vehicle  10  behind front grille  14 .  FIG. 2  shows the apron assembly  16  of vehicle  10  and the front bumper  18  of vehicle  10  mechanically coupled to the apron assembly  16 . The location of the front bumper relative to the apron assembly may vary between assemblies because of the variation in the location of holes on the apron end for receiving bumper screws. In certain embodiments, the hole location variation can be in the range of +/−3.0 mm. Moreover, the size, i.e. diameter, the screw size can vary between assemblies, for example by +/−0.5 mm. These variations may render the surfaces of the bumper unsuitable for mounting an FLR unit without expensive and time-consuming manual alignment after the mounting operation. 
     In at least one embodiment, a mounting bracket is provided that decouples the FLR unit alignment angle from the bumper surface, or other surfaces susceptible to wide variations between vehicle assemblies. The mounting bracket of these embodiments can be used to adequately align the FLR unit within an acceptable angular tolerance without manual alignment. 
       FIG. 3  depicts a schematic, cross-sectional, side view illustration of the vertical angle tolerances of a FLR unit  100  mounted on a vehicle  102 , which includes grill reinforcement opening (GOR)  104 , body  106 , chassis  108  and wheels  110 . The vehicle  102  is positioned on a ground plane  112 . Line  114  bisects the cross-sectional, side view of the FLR unit  100  and extends outwardly from the face  114  of the FLR unit  100 . Line  114  is also substantially parallel to the ground plane  112 , which is utilized as the reference plane for the radar beam angle calculation. As shown in  FIG. 3 , radar beam  116  is positioned at a preferred vertical angular alignment, i.e. radar beam  116 , having a beam width of 4.4 degrees, is bisected by line  114 . 
     In other embodiments, the FLR unit  100  can mounted to the chassis  108  and either the GOR  104  or body  106  using one or more of the vehicle mounting brackets disclosed herein. 
     In certain embodiments, the FLR unit can be used for its intended purposes outside of the preferred alignment position. Lines  118  and  120  depicted the upper and lower boundaries of a range of tolerable vertical alignments. In the embodiment shown in  FIG. 3 , the radar beam  116  can vary +2.1 degrees to −2.0 degrees relative to the preferred position while maintaining its sensing functionality for its intended purpose relating to vehicle safety systems. In other embodiments, the tolerable range can be +/−1.0 degree from the preferred position, and in yet other embodiments, the tolerable range can be +/−3.0 degrees from the preferred position. Beam  120  is outside of the tolerable range, and therefore, represents a failed alignment, which may require manual adjustment. 
     The vertical angular position of various vehicle components, such as the mounting bracket for FLR unit  100 , the bumper  104 , and the chassis  108 , after assembly can add to vertical misalignment of the FLR unit. In at least one embodiment of the present invention, the FLR unit  100  is mounted to the body at a control point, which is described in more detail below, to thereby reduce the effect of such misalignment caused by vehicle component assembly. 
     Moving back to  FIGS. 1 and 2 , the apron assembly  16  and front bumper  18  are generally disposed behind front bumper fascia  20 . In at least one embodiment, the FLR unit  12  is mounted to a mounting bracket  22 , which is mounted to the front bumper  18  and rail  24  of the apron assembly  16 . 
       FIG. 4  shows an exploded view of mounting bracket  22 , which generally includes a bracket face  26  and a bracket arm  28 . The mounting bracket can be made of a suitably strong material, such as steel or hot-rolled carbon steel. The mounting bracket can also be electronically coated to resist rusting. 
     The bracket face  26  has a generally rectangular perimeter forming an opening  30  for receiving a portion of the FLR unit  12 . Holes  32  are positioned on bracket face  26 . FLR unit  12  includes corresponding holes  34  positioned on mounting surface  36 . 
     Screws  38  are inserted into holes  32  and holes  34  to attach the FLR unit  12  to the bracket face  26 . In at least one embodiment, the screws are weld screws. It should be appreciated that screws are but one example of the type of fastener that can be utilized to fix the FLR unit to the mounting bracket. Other non-limiting examples include rivets, pins, and clips. Moreover, the use of holes and fasteners provides but one example for fixing the FLR unit to the mounting bracket. Other fixtures can be utilized, such as, welded fixtures. The screws  38  can also receive spacers  40 , which are positioned proximate to the mounting surface  36 . In at least one embodiment, the spacers are weld spacers. Nut  42  or other spacer can be interposed between one or more screws  38  and the bracket face  26 , as shown in  FIG. 4 . 
     Mounting bracket  22  includes spaced apart upper and lower braces  42  and  44  for supporting and bracing the FLR unit  12  after assembly. The upper brace  42  is affixed to the upper edge of bracket face  26  and the lower brace  44  is affixed to the lower edge of bracket face  26  and the lower edge of bracket arm  28 . 
     In at least one embodiment, tab  46  is connected to and extends outwardly and upwardly from the upper edge of bracket frame  24 . Tab  46  includes a hole  48  formed therein. In at least one embodiment, tab  50  is connected to and is substantially perpendicular to bracket arm  28 . Tab  50  includes an opening  52  formed therein. In at least one embodiment, screws  54  and  56  are inserted into hole  48  and opening  52 , respectively, and holes  58  and  60  are positioned on the underside  62  of front bumper  18 , as shown in  FIG. 5 , to attach the mounting bracket  22  to the bumper  18 . In at least one embodiment, the screws are weld screws. It should be appreciated that screws are but one example of the type of fastener that can be utilized to fix the FLR unit to the front bumper. 
     As depicted in  FIGS. 2 and 4 , bracket arm  28  includes a proximate end portion  64  connected proximate to a side edge of the bracket face  24  and a distal end portion  66 . A bracket arm frame portion  68  is disposed between end portions  64  and  66  for providing support and strength to bracket arm  28 . 
     The distal end portion  66  includes a mounting portion  70 , which includes first hole  72  and second hole  74 . As depicted in  FIG. 2 , mounting surface  76  of rail  24  is oriented substantially vertically relative to the ground plane. The mounting surface  76  includes first and second holes  78  and  80  spaced apart a distance substantially equal to the spaced apart distance of first and second holes  72  and  74  of the mounting portion  70 . 
     In at least one embodiment, the rail mounting surface  76  is a control surface and one or both of the first and second holes  78  and  80  are positioned relative to control points on the control surface. Control points refer to fixed points on the control surfaces of vehicle parts during assembly. Control points can govern the location of position-sensitive parts and systems, such as suspension members, engine mounts, and body mounts, during assembly. Uncontrolled surfaces and points can refer to those surfaces and points that are not related to governing the location of position-sensitive parts. For example, a front bumper surface can be an uncontrolled surface. 
     In at least one embodiment, first hole  78  is positioned substantially centered on a control point  82  located on the rail mounting surface  76 . It should be appreciated that the hole does not have to be exactly centered on the control point, and in at least one embodiment, a tolerance of +/−1.0 millimeter is suitable for positioning the FLR unit. In other embodiments, the center hole position can be located within +/−2.0 millimeters from the control point. This tolerance can be any range such that the total vertical tolerance stack of the mounting elements of the mounting bracket and the control surface, taking into account the aft distance of the FLR unit face to the control point, provides a vertical angular alignment within a tolerable range. In at least one embodiment, the aft distance is 300 mm and the vertical tolerance stack is 4.5 mm. Therefore, the angular variation is 0.85 degrees, which is suitable for alignment if the angular accuracy tolerance for the FLR unit is +/−2.0 degrees. 
     Screw  84  is inserted into first holes  72  and  78  to fix bracket arm  28  to rail  24 . After the rail  24  and the bracket arm  28  are coupled by screw  84 , screw  86  is inserted into second holes  74  and  80  to reinforce the connection between the rail  24  and the bracket arm  28 . In certain embodiments, the location of second hole  80  is not defined relative to a control point. 
     In at least one embodiment, the tabs  46  and  50  are coupled to the front bumper underside  62  as the first step in the mounting process, followed by the step of mounting the distal end mounting portion  70  to the rail  24 . In certain embodiments, the tabs  52  and  56  are formed of a deformable material, such as a deformable hot rolled steel, or deformable plastic although other deformable materials are within the spirit of this invention. 
     Upon mounting the distal end mounting portion  70  to the rail  24 , the deformable tabs bend to comply with the front bumper underside  62 , thereby decoupling the alignment angle of the mounting bracket  22  from the angle of the underside surface  66 . Rather, the alignment angle of the mounting bracket  22  is substantially controlled by the mounting of the bracket arm  28  relative to a control point, which imparts limited variance of the alignment angle for the mounting bracket  22  and the mounted FLR unit  12 . 
     The control surface containing the control point as shown in  FIG. 2  is substantially vertical to the ground plane of the vehicle and substantially orthogonal to the FLR unit face after assembly of the mounting bracket with the FLR unit to the vehicle. In other embodiments, the controlled mounting surface is not substantially vertical to the ground plane and/or the controlled mounting surface is not substantially orthogonal to the FLR unit face after assembly of the mounting bracket with the FLR unit to the vehicle. It should be appreciated that the control surface containing the control point can have any angular association with the ground plane and FLR unit face provided that the bracket assembly using such a control point results in a vertical angular alignment of the FLR unit face within a tolerable range. A non-limiting example of a tolerable range is a range that does not result in the need for manual alignment. 
       FIG. 6  depicts a schematic, perspective view of a mounting bracket  150  and controlled mounting surface  152  with an alternative geometrical orientation according to an embodiment of the present invention. Substantially horizontal mounting portion  154  is mounted to substantially horizontal controlled mounting surface  152  via screws  156 . 
     As shown in  FIG. 4 , a screw  84  is utilized to fix the distal end mounting portion  70  to the rail  24 . It should be appreciated that other mounting features can be utilized to provide this fixture.  FIG. 7  depicts a stud  200  projecting orthogonally and outwardly from horizontal controlled mounting surface  202 . Stud  200  is inserted into hole  204  of distal end mounting portion  206  of mounting bracket  208  to affix the distal end mounting portion  206  to the rail  210 . Screw  212  can be inserted into hole  214  and hole  216  to further support the connection between rail  210  and mounting bracket  208 .  FIG. 8  depicts a stud  250  projecting orthogonally and outwardly from vertical controlled mounting surface  252 . Stud  250  is inserted into hole  254  of distal end mounting portion  256  of mounting bracket  258  to affix the distal end mounting portion  256  to the rail  260 . Screw  262  can be inserted into hole  264  and hole  266  to further support the connection between rail  260  and mounting bracket  258 . 
     It should be appreciated that the vehicle mounting brackets of one or more embodiments of the present invention can be applied to any sensing technology, such as laser, lidar, radar, ultrasonic cameras and vision cameras. 
     Moreover, it should be appreciated that the vehicle mounting brackets of the present invention can be applied to any directional sensors, for example, front, side and rear-facing sensors. 
     Further, it should be appreciated that the vehicle mounting brackets of one or more embodiments of the present invention can be applied to headlamps. In certain embodiments, the vehicle mounting bracket can be used to automatically align headlamps without any manual alignment steps. 
     While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.