Patent Publication Number: US-2023136633-A1

Title: Vehicle wheel location and path determination

Description:
FIELD 
     The present disclosure relates to a system to determine and display the location and path of one or more vehicle wheels. 
     BACKGROUND 
     Many vehicles today include a camera that provides to a display within a passenger compartment of the vehicle an image of the area in which the vehicle is located. Some cameras are used when the vehicle is traveling in reverse to show the area behind the vehicle, and may show a path of the vehicle that changes as the steering wheel is rotated to change the desired steering angle of the vehicle. Some vehicles also include obstacle detectors that provide a warning if the vehicle is approaching and may strike an obstacle that is within the projected path of the vehicle. However, due to, for example, uneven terrain or vehicle body roll, the actual location of the vehicle wheels and thus, the actual path to be taken by the wheels can vary from a nominal position and nominal wheel path. 
     SUMMARY 
     In at least some implementations, a vehicle includes a vehicle body including suspension components, multiple wheels coupled to the vehicle body by the suspension components, a suspension sensor coupled to one of the suspension components or at least one of said multiple wheels, a camera carried by the vehicle body, a display carried by the vehicle body and connected to the camera to display at least part of the camera view, a processor receiving input from the suspension sensor, and memory coupled to the processor. The memory includes a program from which an actual horizontal wheel position is determined as a function of a vertical position of the at least one of said multiple wheels. And the processor causes an image representative of the actual horizontal wheel position to appear on the display, and wherein vertical is in the direction of gravity and horizontal is perpendicular to the direction of gravity. 
     In at least some implementations, the suspension sensor is a ride height sensor coupled to at least one of the suspension components and responsive to vertical movement of the at least one of the suspension components. 
     In at least some implementations, the program causes the processor to the display an image representative of the position of two horizontally spaced apart wheels of said multiple wheels, and wherein the suspension components comprise an independent suspension for each of said two horizontally spaced apart wheels. 
     In at least some implementations, the program causes the processor to the display an image representative of the position of two horizontally spaced apart wheels of said multiple wheels, and wherein the suspension components include an axle to which each of said two horizontally spaced apart wheels is coupled. In at least some implementations, the suspension sensor is responsive to movement of the axle caused by movement of the wheels coupled to the axle, and wherein the actual horizontal position of the wheels coupled to the axle is determined as a function of the vertical position of the axle and of an angle of axle indicative of the vertical position of the wheels coupled to the axle. 
     In at least some implementations, the vehicle includes a steering sensor coupled to a steerable component of the vehicle and coupled to the processor to provide a signal indicative of a steering angle, and the program causes the processor to display a projected path of travel of the vehicle that is based upon the actual horizontal wheel position. In at least some implementations, the projected path is determined as a function of both the actual horizontal wheel position and the steering angle of the at least one of said multiple wheels. In at least some implementations, the projected path is determined as a function of a difference between the steering angle and the angle of the at least one of said multiple wheels determined by the program as a function of the vertical position of the at least one of said multiple wheels. 
     In at least some implementations, the suspension sensor is a first suspension sensor responsive to movement of a first one of the suspension components that is associated with a first wheel of the multiple wheels, and wherein the vehicle includes a second suspension sensor that is coupled to a second one of the suspension components that is associated with a second wheel of the multiple wheels that is horizontally spaced apart from the first wheel, and wherein the program causes the processor to the display an image representative of the position of both the first wheel and the second wheel based at least in part upon the actual horizontal position of the first wheel and second wheel. In at least some implementations, the camera is a forward facing camera having a view of the terrain to be traversed by the vehicle when traveling in a forward direction, and wherein the first wheel and second wheel are front wheels of the vehicle. In at least some implementations, the camera is a rearward facing camera having a view of the terrain to be traversed by the vehicle when traveling in a reverse direction, and wherein the first wheel and second wheel are rear wheels of the vehicle. 
     In at least some implementations, a method of determining wheel position in a vehicle, comprises the steps of: 
     a) determining at least one of a height of: 1) a suspension component associated with at least one wheel of the vehicle, or 2) the at least one wheel of the vehicle; 
     b) determining the horizontal position of the at least one wheel as a function of the height; 
     c) determining a steering angle of the vehicle; 
     d) calculating a path of the vehicle as a function of the steering angle and either a) the horizontal position of the at least one wheel or 2) the height determined in step a); and 
     e) displaying the horizontal position of at least one wheel, or the wheel path or both. 
     In at least some implementations, the vehicle has a pair of front wheels and a pair of rear wheels, and step a) is accomplished by determining a height of suspension components associated with at least one of: a) both front wheels of the vehicle; or b) both rear wheels of the vehicle. In at least some implementations, the height is the height associated with both front wheels. 
     In at least some implementations, step e) is accomplished by displaying a symbol on a display of the vehicle, with the symbol located in a position indicative of the actual position of the at least one wheel. 
     In at least some implementations, step a) is accomplished with a suspension sensor that is responsive to changes in the position of a suspension component. In at least some implementations, step a) is accomplished with a first suspension sensor responsive to changes in position of a first front wheel of the vehicle and with a second suspension sensor responsive to changes in position of a second front wheel of the vehicle. In at least some implementations, the first front wheel and second front wheel are coupled to a solid axle. In at least some implementations, the first front wheel and second front wheel are coupled to a body of the vehicle by independent suspension assemblies. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings provided hereinafter. It should be understood that the summary and detailed description, including the disclosed embodiments and drawings, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the invention, its application or use. Thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front view of a vehicle shown at a nominal ride height; 
         FIG.  2    is a front view of the vehicle shown with the wheels and suspension in an extending position relative to a body of the vehicle; 
         FIG.  3    is a diagrammatic view of two wheels of a vehicle coupled to a body by independent suspension components, and with the two wheels on surfaces at different heights; 
         FIG.  4    is a view similar to  FIG.  3    illustrating position of the wheels due to vehicle body roll; 
         FIG.  5    is a view of vehicle wheels coupled by an axle with the wheels shown on a surface wherein the wheels are at the same level and at a nominal ride height; 
         FIG.  6    is a view similar to  FIG.  5    and showing the wheels on surfaces of different heights; 
         FIG.  7    is a view similar to  FIG.  5    and showing the wheels at the same height but with the suspension in an extended position; 
         FIG.  8    is an illustration of a bump steer effect on a vehicle including a solid axle; 
         FIG.  9    is an illustration of wheel angle change with a wheel coupled to a vehicle body by an independent suspension that is shown in a retracted or compressed position; 
         FIG.  10    is a schematic view of a system including multiple suspension components for multiple vehicle wheels, a steering component, a camera, a processor with memory and a display; and 
         FIG.  11    is a flowchart of a method for determining wheel position and wheel path as a function of steering angle and suspension position. 
     
    
    
     DETAILED DESCRIPTION 
     Referring in more detail to the drawings,  FIG.  1    illustrates the front of a vehicle  10  having a body  12  and multiple wheels  14   a,    14   b  coupled to the body  12  by a vehicle suspension  16  having various suspension components  18  as is known. Two front wheels  14   a,    14   b  are shown in  FIG.  1    and they are spaced apart horizontally, sometimes called a cross-car direction, extending between driver and passenger sides of the vehicle  10 , and shown by arrow  20 . The front of the vehicle  10  leads the rear of the vehicle  10  in a fore-aft direction extending into the page in  FIG.  1   , and the body  12  is suspended off a ground surface by the wheels  14   a,    14   b  and vehicle suspension  16 , in a vertical direction shown by arrow  22 , which is parallel to the direction of gravity when the vehicle  10  is on a flat, level road oriented perpendicular to gravity. As the vehicle  10  moves, the wheels  14   a,    14   b  rotate about a horizontal axis  24 . 
     As shown in  FIG.  10   , the vehicle  10  may also include a steering input, such as a steering wheel  26 , a camera  28 , a controller  30 , and a display  32 . The steering input is any device by which a driver may command a change in the steering angle of the wheels  14   a,    14   b  to turn the vehicle  10 . The steering angle changes as the wheels  14   a,    14   b  are rotated about a vertical axis  34  ( FIG.  1   ). 
     The camera  28  is carried by the vehicle body  12  and has a lens with a viewing angle that includes an area to be traversed by the vehicle  10 . When the vehicle  10  is moving in the forward direction, a forward facing camera  28  can be used to view, sense or display the terrain in front of the vehicle  10 . When the vehicle  10  is moving in reverse, that is in the rearward direction, a rearward facing camera  28  can be used to view, sense or display the terrain at the rear or behind the vehicle  10 . So the vehicle  10  may have one or more cameras, as desired, to show one or more areas of the environment in which the vehicle  10  is located. 
     The display  32  may be carried by the vehicle body  12 , such as within a passenger compartment of the vehicle  10 , and may be coupled to the camera  28  to provide a view of the area to be traversed by the vehicle  10 . The camera  28  and display  32  may be coupled to the controller  30  which may include a processor  36  and memory  38  that includes executable programs or instructions. The display  32 , processor  36  and memory  38  may be of suitable types and such components in vehicles are well-known and will not be further described herein. By way of examples, without limitation, the display may be an LED or OLED screen, the processor may be any desired type of microprocessor and the memory may be integrated with the microprocessor or separate from it, a reprogrammable or flash EEPROM (electrically erasable, programmable read-only memory), RAM (random access memory), ROM (read-only memory), EPROM (erasable, programmable read-only memory), or any other suitable non-transitory computer readable medium. 
       FIG.  2    illustrates the same vehicle  10  as in  FIG.  1    but with the vehicle suspension  16  in an extended state, sometimes called suspension droop or rebound, which occurs when the vehicle  10  travels over a portion of the road lower than a previously traveled portion. In the example shown, both wheels  14   a,    14   b  are lowered the same extent such as occurs when the vertical drop or dip in the road is level horizontally. In this position, the wheels  14   a,    14   b  have extended away from the vehicle body  12  as permitted by movement of the suspension components  18 , such as springs, shocks, and various linkages, for those wheels  14   a,    14   b.    
     In the example of  FIGS.  1 ,  2  and  5 - 8   , the vehicle suspension  16  includes a so-called solid axle  40  with the wheels  14   a,    14   b  coupled to opposite ends of the axle  40  in known manner. The suspension  16  moves from a nominal position, shown in  FIG.  1   , to the extended position shown in  FIG.  2    about a pivot or attachment point that causes horizontal displacement of the axle  40  and wheels  14   a,    14   b.  Thus, the wheels  14   a,    14   b  move laterally as the suspension  16  and wheels  14   a,    14   b  move vertically due to vertical changes in the surface on which the vehicle  10  is traveling. In the example shown, the wheels  14   a,    14   b  shift horizontally to the right (as shown in  FIG.  1   ) as the suspension  16  extends away from the vehicle  10 , as can be seen by comparison of the horizontal position of the wheels  14   a,    14   b  relative to the vehicle body  12  in  FIG.  2    as compared to the horizontal wheel position in  FIG.  1   . Further, the wheels  14   a,    14   b  shift horizontally to the left (as viewed in  FIG.  2   ) as the suspension  16  moves in the opposite direction, toward the vehicle body  12  and toward a compressed or retracted position. 
       FIG.  3    illustrates part of a vehicle  10 ′ having a different suspension  16 ′ which is a so-called independent suspension arrangement in which separate linkages  42  connect the wheels  14   a,    14   b  to the vehicle body  12 . That is, the linkages/suspension  42  of one wheel  14   a  is independent of the other wheel(s)  14   b.  In  FIG.  3   , the wheel  14   a  on the left is on an elevated surface  44  compared to a nominal, flat and level surface  46 , and the wheel  14   b  on the right is on a lower surface  48  compared to the flat and level surface  46 . Lines  50  show the centerline of the wheels  14   a,    14   b  when both wheels  14   a,    14   b  are on the flat and level surface  46  (e.g. at the same vertical level) and when the vehicle  10 ′ is at a nominal ride height, that is, the suspension  16 ′ is in the position or height at which it is when the vehicle  10 ′ is at rest. A line  52  shows the centerline of the left wheel  14   a  and indicates that, in this suspension arrangement, the left wheel  14   a  shifted to the right as it was raised relative to the vehicle body  12 . A line  54  shows the centerline of the right wheel  14   b  and indicates that, in this suspension arrangement, the right wheel  14   b  shifted to the left as it was lowered relative to the vehicle body  12 . 
       FIG.  4    shows the vehicle  10 ′ of  FIG.  3    with the wheels  14   a,    14   b  on a flat and level surface, so the wheels  14   a,    14   b  are at the same vertical height, but the vehicle body  12  has rolled or rotated a bit counterclockwise. Line  55  is the centerline of the vehicle body  12  without body roll, and line  47  shows the body centerline with the body roll. Lines  56  and  58  show the centerline of the right wheel  14   b  without the body roll and with, respectively, and indicate that this direction of body roll causes the right wheel  14   b  to shift to the left. Lines  60  and  62  show the centerline of the left wheel  14   a  without the body roll and with, respectively, and indicate that this direction of body roll causes the left wheel  14   a  to shift to the left. Body roll in the opposite direction would cause the wheels  14   a,    14   b  to shift to the right. 
       FIGS.  5 - 7    illustrate the front wheels  14   a,    14   b  and axle  40  of the vehicle  10  of  FIGS.  1  and  2   , which includes a track bar  64  coupled at one end to the axle  40  and at its opposite end to the vehicle body  12  (as best shown in  FIGS.  1  and  2   ). A line  66  represents a surface of the vehicle  10  and/or a horizontal reference. In  FIG.  5   , the axle  40  is at the nominal vertical height and the wheels  14   a,    14   b  are on a flat and level surface, which is the position of the vehicle  10  shown in  FIG.  1   . 
     In  FIG.  6   , the wheels  14   a,    14   b  are on an inclined surface wherein the left wheel  14   a  is vertically lower than the right wheel  14   b,  and the axle  40  is inclined relative to the vehicle body  12  (e.g. line  66 ). In this example, the right wheel  14   b  has moved upward relative to the vehicle body  12  (e.g. up farther in a corresponding wheel well) and the left wheel  14   a  has moved away from the vehicle body  12 . The track bar  64  and/or other suspension components  18  constrain movement of the axle  40  and wheels  14   a,    14   b  and the wheels  14   a,    14   b  shift to the right (as viewed in  FIG.  6   ) compared to the position of the wheels  14   a,    14   b  in  FIG.  5   . When the opposite wheel displacement occurs (i.e. the right wheel  14   b  lower than the left wheel  14   a ) the wheels  14   a,    14   b  will shift to the left. 
     In  FIG.  7   , the right and left wheels  14   a,    14   b  are vertically at the same level but have moved away from the vehicle body  12 , which is a position of the vehicle  10  like that shown in  FIG.  2   . The track bar  64  and/or other suspension components  18  constrain movement of the axle  40  and wheels  14   a,    14   b  and the wheels  14   a,    14   b  shift to the right (as viewed in  FIG.  7   ) compared to the position of the wheels  14   a,    14   b  in  FIG.  5   . When the opposite wheel displacement occurs (i.e. the wheels  14   a,    14   b  move toward the vehicle body  12  compared to the nominal position) the wheels  14   a,    14   b  will shift to the left. 
     In  FIG.  8   , two wheels  14   a,    14   b  and a solid axle suspension  16  arrangement are again shown, as is a steering assembly including a steering wheel  26 , steering shaft  68  and steering linkages  70  by which the steering angle of the wheels  14   a,    14   b  may be changed. Because the steering assembly is coupled to the wheels  14   a,    14   b,  as the wheels  14   a,    14   b  shift vertically, the steering linkages  70  are displaced and this causes a change in the steering angle of the wheels  14   a,    14   b.  That is, the wheel movement causes a change in steering angle that is not commanded by a driver rotating the steering wheel  26 . This is sometimes called “bump steer.” 
     Further, in  FIG.  9   , a wheel  14   b  coupled to a vehicle body  12  by an independent suspension  16 ′ is shown. In the position shown in  FIG.  9   , the wheel  14   b  is vertically raised toward the vehicle body  12  relative to a nominal vertical position of the wheel  14   b.  This causes a compression or retraction of the suspension components  18  which rotate the wheel  14   b  about the vertical axis  34 , causing a change in the angle of the wheel  14   b  relative to the intended direction of travel. This is an example of another condition in which the angle of the wheel  14   b  may differ from a driver commanded angle of the wheel, and is sometimes referred to as a change in the toe angle of the wheel and is illustrated by line  72  which shows the intended angle of the wheel and line  74  which shows the angle of the wheel caused by the vertical displacement of the wheel in  FIG.  9   . 
     Thus, vertical movement of the suspension  16 ,  16 ′ and wheels  14   a,    14   b  in a vehicle  10 ,  10 ′ and/or vehicle body roll, cause horizontal displacement of the wheels  14   a,    14   b  and may also cause changes to the angle of the wheels  14   a,    14   b  relative to the intended direction of vehicle travel. These changes to the wheel&#39;s horizontal position and angle can be important in different operating conditions, such as when a vehicle  10  is navigating obstacles which is common in off-road travel, that is, travel on unpaved roads. Knowledge of the actual horizontal position and or angle of one or more wheels  14   a,    14   b  may help a driver adequately navigate an obstacle. 
     Accordingly, a system and method are provided to determine and provide a display of an actual wheel position and angle (e.g. projected wheel path based upon wheel position and angle). A representative system  76  is shown in  FIG.  10   . This system  76  includes multiple wheels  14   a,    14   b,    14   c,    14   d  (where wheels  14   c,    14   d  are rear wheels of the vehicle  10 ) that are connected to the vehicle body  12  by suspension components  18 . A suspension sensor  78  is associated with at least one and up to each wheel  14   a,    14   b,    14   c,    14   d  and may be carried by a suspension component  18 , a wheel  14   a,    14   b,    14   c,    14   d  or the vehicle body  12 . The suspension sensors  78  are coupled to and provide an input signal to the controller  30  to provide an indication of the vertical position of the wheels  14   a,    14   b,    14   c,    14   d.  While multiple suspension sensors  78  are shown in  FIG.  10   , specifically one suspension sensor  78  for each wheel  14   a,    14   b,    14   c,    14   d  of a vehicle  10  (shown as having four wheels  14   a,    14   b,    14   c,    14   d,  but the vehicle may have a different number of wheels), fewer suspension sensors  78  including only one suspension sensor  78  might be used. For example, in a solid axle suspension  16  the angle of the axle  40  may be used to determine the vertical wheel position(s) and this might be determined with a single suspension sensor  78  If determination of wheel position and angle is desired for both forward and rearward travel, then a suspension sensor  78  might be used for both front and rear axles. So the system includes at least one suspension sensor  78  that is used to determine the vertical height of at least one wheel  14   a,    14   b,    14   c,    14   d.    
     As noted above, the system  76  also includes a steering assembly including a steering wheel  26 , and a steering sensor  80  that determines an intended steering angle for the vehicle  10 . The steering sensor  80  is coupled to any desired component of the steering assembly and also to the controller  30  to provide a steering angle input to the controller  30 . 
     So the controller  30  has inputs from both the suspension sensor(s)  78  and steering sensor(s)  80  which provide information regarding vehicle ride height and intended steering angle, and from that information, the controller  30  determines the horizontal position of one or more wheels  14   a,    14   b  and the steering angle for one or more wheels  14   a,    14   b.  The controller  30  can then cause the display  32  to, based on these inputs, show an image of one or both the actual horizontal wheel position and the path that one or more wheels  14   a,    14   b  will take with continued travel under the current conditions. This may be shown on the display  32  as one or more graphics overlaid on an image provided by the camera  28 . For example, as shown in  FIG.  10   , when the vehicle  10  is traveling forward, the view captured by a forward facing camera  28  may be shown on the display  32 , and one or more of: 1) a first graphic  82  may be shown on the display  32  that is indicative of the actual horizontal position of a front left wheel  14   a;  2) a second graphic  84  may be shown on the display  32  that is indicative of the actual horizontal position of a front right wheel  14   b;  3) a third graphic  86  may be shown on the display  32  that is indicative of the forward path of the front left wheel  14   a;  and 4) a fourth graphic  88  may be shown on the display  32  that is indicative of the forward path of the front right wheel  14   b.  In at least some implementations, instead of the first and second graphics  82 ,  84 , the actual horizontal positions of the left and right front wheels  14   a,    14   b  may be illustrated on the display  32  by a portion of the paths that is, a portion of the third and fourth graphics  86 ,  88 , for example, a beginning or proximal end  90  of the third and fourth graphics  86 ,  88 . In at least some implementations, the first and second graphics  82 ,  84  may be discrete polygons like rectangles indicating the contact patch for each wheel  14   a,    14   b  which is the portion of the wheel actually engaged with the ground, and the third and fourth graphics  86 ,  88  may be elongated straight or curved lines or polygons laid out along the camera view. 
     The controller  30  may utilize a method for determining wheel position and angle, such as the method  92  set forth in  FIG.  11   . The method  92  starts at step  94  and in step  96  at least one ride height is determined. The ride height might be the relative position of a suspension component  18  or wheel  14 ,  14   b,  for example, relative to a nominal or at rest position of such component. In the example method of  FIG.  11   , a left and right side ride height is determined. When the vehicle  10  is traveling forward, the ride height relative to the front wheels  14   a,    14   b  of the vehicle  10  may be determined. The ride height of the rear wheels  14   c,    14   d  may be determined as well, if desired for example, to determine body roll fore/aft and/or horizontal/cross-car roll, and/or when the vehicle  10  is traveling in reverse and a rear camera  28  is providing an image of the terrain over which the vehicle  10  is moving. The ride height may be altered due, fore example, to an uneven road or vehicle body roll. 
     From the ride height determination, the controller  30  may determine in step  98  a horizontal position of one or more vehicle wheels  14   a,    14   b.  As discussed above, this determination can be made by the controller  30  executing a program that includes data about the suspension  16  of the vehicle  10 . In view of the geometries and arrangement of the suspension components  18 , the horizontal offset of the wheels  14   a,    14   b,  if any, due to ride height changes from a nominal ride height can be determined. This can be calculated mathematically and/or determined empirically through testing of a vehicle, or a combination of both, as desired. 
     Next, in step  100 , the steering angle is determined and a wheel path is determined based upon both the steering angle and the ride height information and/or actual horizontal wheel position as determined in step  98 . As discussed above, the steering angle may be an actual or approximated/determined wheel angle, or an angle of a component in the steering assembly such as, but not limited to, the steering column or steering rack. The wheel path determined in step  100  is the wheel path the wheels  14   a,    14   b  will actually take based upon the current suspension position/ride height of the vehicle  10 , and not a nominal wheel path based only on the steering angle. The system may determine a bump steer effect, among other things, that may affect the steering angle as the vehicle  10  travels over uneven terrain. 
     Finally, one or both of the wheel path and actual horizontal wheel position is communicated to the driver, such as by displaying information on the vehicle display  32  in step  102 . The information may be provided in the form of graphics  82 ,  84 ,  86 ,  88  overlaid on an image provided from the camera  28 . In the example of  FIG.  10   , the actual wheel position is shown on the display  32  by separate symbols or graphics  82 ,  84 , shown as rectangles in this example, arranged on the display  32  and relative to an actual image or live feed from the camera  28  so a driver can see the actual wheel position relative to the terrain over which the vehicle  10  is traveling. The wheel path may be provided by graphics  86 ,  88  such as curved lines or polygons that represent the determined tire position along the currently steered path of the vehicle  10 , taking into account both ride height/suspension data and the steering angle. As noted above, the wheel position may be indicated by a portion of the wheel path graphics  86 ,  88  instead of by separate symbols, such as by a proximal end  90  of the path nearest to the vehicle  10 , or by a portion of the path provided in a different color or otherwise distinguishable from the remainder of the path. Further, a symbol having the appearance of a wheel may be used to represent the wheel for improved visualization of the wheel position and orientation by the driver. 
     Thus, instead of displaying to the driver a nominal wheel position or nominal projected path of the wheels  14   a,    14   b  that is based upon steering angle but not suspension position or wheel height, the system can provide a more accurate information to a driver to help the driver better navigate uneven terrain and obstacles like rocks, stumps, holes, ruts, and the like, in the vehicle&#39;s path. The system is responsive to both ride height and steering angle and may provide instantaneous or real-time display of the wheel position and/or wheel path as the steering angle and/or ride height data changes while the vehicle  10  moves.