Abstract:
A method and system for orienting the attitude of a vehicle. The method includes determining a path of travel of the vehicle, determining a slope of the terrain over the path of travel, and adjusting a height of at least one adjustable support of the vehicle.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT 
       [0001]    This invention was made and funded by the U.S. Government, specifically by the U.S. Army Tank-Automotive &amp; Armaments Co. under Contract W56HZV-05-9-0002. The U.S. Government has certain rights in the invention. 
     
    
     FIELD OF THE INVENTION 
       [0002]    A method and system for orienting the attitude of a vehicle, more particularly, a method and system of increasing or enhancing the side slope operating capabilities of a vehicle. 
       BACKGROUND OF THE INVENTION 
       [0003]    Often, operation of an off-road vehicle requires that the vehicle proceed over non-level ground. In connection with such operation, the path of the vehicle may not remain level but, instead, may follow a hillside. Where the path is not horizontal, the attitude of the vehicle acquires the attitude or slope of the path and the vehicle may become prone to instability, that is, to rolling over or sliding downhill. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    Stability of the vehicle when traversing a non-level or non-horizontal path is enhanced by the vehicle being oriented such that the plane of its chassis is more level or more horizontal than if the plane of the chassis were parallel to the plane of the path along the hillside. The side slope capability of the vehicle is then increased beyond the side slope capability based on the track width and the center of gravity of the vehicle alone. 
         [0005]    The method and system of the present invention increases a vehicle&#39;s side slope traversing capabilities. With fully controllable ride height of individual wheel stations, such as can be provided on certain tactical vehicles, it is possible to drive the down hill side of the vehicle to its maximum ride height, and the up hill side to its minimum ride height, thus tending to level the vehicle and increase its side slope operational capability. 
         [0006]    This invention is particularly useful for, but not limited to, Future Tactical Truck Systems (FTTS). Many off-road vehicles require that they can operate on very steep side slopes, and the present invention provides a method and system for increasing the side slope capability as mentioned above. 
         [0007]    The present invention provides a fully adjustable independent suspension, such as pneumatic, hydraulic, and the like, with significant ride height adjustment capabilities, so that it is possible to lower the uphill side of a vehicle to its lowest ride height setting, while simultaneously raising the downhill side of the vehicle to its maximum ride height setting. This can be done prior to the vehicle actually encountering the sloped terrain and under the control of the driver using his own senses, or using a vision system that looks at and analyzes the upcoming terrain. 
         [0008]    According to one aspect of the present invention, a method and system for adjusting an orientation of a chassis of a vehicle relative to a terrain includes determining a path of travel of the vehicle over the terrain, determining a slope of the terrain over the path of travel, and adjusting a height of one or more adjustable supports of the vehicle on the basis of the path of travel and the slope of the terrain over the path of travel, said adjusting resulting in a more horizontal orientation of the chassis of the vehicle during traverse of the path of travel by the vehicle. 
         [0009]    In one embodiment according to the present invention, the adjustable support may be a dynamically adjustable independent support. In another embodiment according to the present invention, the adjustable support may be an adjustable independent wheel suspension. In a further embodiment according to the present invention, determining the path of travel over the terrain may be manual. Determining of the path of travel may be by an occupant of the vehicle who may be a driver of the vehicle. 
         [0010]    In another embodiment according to the present invention, determining the slope of the terrain over the path of travel may be manual. Determining the slope of the terrain over the path of travel may be by an occupant of the vehicle who may be a driver of the vehicle. 
         [0011]    In a certain embodiment according to the present invention, adjusting the height of at least one adjustable support may be manual on the basis of the path of travel over the terrain and the slope of the terrain over the path of travel. Adjusting the height of at least one adjustable support may be by an occupant of the vehicle who may be a driver of the vehicle. Adjusting the height of at least one adjustable support may be through manual interaction of the occupant with a controller that may include wireless communication between the controller and at least one adjustable support. 
         [0012]    In another embodiment according to the present invention, determining a path of travel of the vehicle over the terrain may include observing the terrain by an occupant of the vehicle who may be a driver of the vehicle. 
         [0013]    In an additional embodiment according to the present invention, determining the slope of the terrain over the path of travel may include observing the slope of the terrain over the path of travel by an occupant of the vehicle who may be a driver of the vehicle. 
         [0014]    In a further additional embodiment according to the present invention, adjusting a height of at least one adjustable support of the vehicle may include increasing a height of at least one down slope adjustable support of the vehicle. In a still additional embodiment according to the present invention, adjusting a height of at least one adjustable support of the vehicle includes decreasing a height of at least one up slope adjustable support of the vehicle. 
         [0015]    For a better understanding of the present invention, together with other and further objects thereof, reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a schematic illustration of a prior art vehicle having adjustable supports. 
           [0017]      FIG. 2A  is a schematic diagram of an adjustable support system for a vehicle according to an embodiment of the present invention. 
           [0018]      FIG. 2B  is a schematic diagram of an adjustable support system for a vehicle according to an embodiment of the present invention, including wireless communication. 
           [0019]      FIG. 3  is a flow chart illustrating a method for adjustment of adjustable supports of a vehicle according to an embodiment of the present invention. 
           [0020]      FIG. 4  is a schematic illustration of a vehicle negotiating a path along a side of a hill in accordance with an embodiment of the present invention. 
           [0021]      FIG. 5A  is a schematic illustration of a front view of a vehicle on horizontal terrain where the chassis is horizontal. 
           [0022]      FIG. 5B  is a schematic illustration of a front view of a vehicle on a non-horizontal path where the chassis is more horizontal than the is the path. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]      FIG. 1  illustrates a prior art vehicle  100  having a cab  160 , a section  127  and a section  125 , and which is capable of carrying a load  105 . Each wheel  110  of vehicle  100  contacts the ground or terrain  120  with a tire  115 . The portion  125  of the vehicle  100  is suspended above each wheel  110  and above the portion  127  by an adjustable wheel support or an adjustable independent wheel suspension  130 , illustrated in schematic fashion in  FIG. 1  and which may include, but is not limited to, an air spring, an air bag, or a hydraulic strut. 
         [0024]    The portion of the vehicle  100  raised by the adjustable supports  130  is the sprung portion  125 , and that portion of the vehicle  100  remaining in fixed height relation with the ground or terrain  120  is the portion  127 . The portion  127  may include, for example, the wheels  110 , including tires  115 , and a portion of the suspension components, such as a portion of the adjustable support  130 , and the axles  142 , and drive train  145 , dependent upon the specific vehicle design in use. 
         [0025]    There is a driver or occupant  140  as well as a controller  135  which will be described below. 
         [0026]      FIG. 2A  is a schematic illustration of the components of an adjustable support system  200  according to one embodiment of the present invention (see also  FIG. 1 ). Each wheel  110  (front left  202 , front right  204 , rear left  206 , and rear right  208 ) is provided with an adjustable support  130  in the form of, but not limited to, an air spring, an air bag, or a hydraulic strut (front left  242 , front right  244 , rear left  246 , and rear right  248 ) supporting the portion  125  of the vehicle  100  over each wheel  110 . 
         [0027]    The adjustable supports  242 ,  244 ,  246 , and  248  provide a variable height support for the portion  125 . Selective expansion or contraction of the adjustable supports  242 ,  244 ,  246 , and  248 , for example, inflation or deflation of the air spring  130 , permits raising or lowering sections of the section  125  relative to each other and to the ground  120  when the vehicle  100  is traversing over non-horizontal terrain. The adjustable supports  242 ,  244 ,  246 , and  248  may be adjusted by actions of a driver, an operator, a passenger, or an observer (more generally referred to as an occupant)  140  ( FIG. 1 ) of the vehicle, directly on the adjustable supports  242 ,  244 ,  246 , and  248  and as a result of the operator  140  interacting with a controller  135  ( FIG. 1 ) to effect adjusting of the adjustable supports. If desired each adjustable support could be adjusted manually. 
         [0028]    The controller  135  of the adjustable supports  242 ,  244 ,  246 , and  248  may be mounted within the cab  160  ( FIG. 1  and  FIG. 2A ) of the vehicle  100  or may be portable and able to be operated from outside of the cab  160  of the vehicle  100 . The portable controller  135  may be in wireless communication with the adjustable supports  130 , that is, with adjustable supports  242 ,  244 ,  246 , and  248 , as between antennas  260  ( FIG. 2B ) communicating between the controller  135  and the adjustable supports  242 ,  244 ,  246  and  248  in  FIG. 2B . The occupant  140  of the vehicle  100  who is usually located within the vehicle  100  may operate the controller  135  manually by providing input directly to the controller  135  to adjust the adjustable supports  242 ,  244 ,  246 , and  248  by, for example, inflating or deflating the air spring or airbag  130  at any of the wheels  110 . Adjustment of the adjustable supports  242 ,  244 ,  246 , and  248  may be dynamic, thereby allowing adjustment of the adjustable supports as the vehicle  100  moves. 
         [0029]      FIG. 3  illustrates a method  300  according to an embodiment of the present invention for the realignment of the attitude or tilt of section  125  relative to that of the ground or terrain  120 . According to this method, the start is at step  302 , and the first step is to determine the attitude of the path of the vehicle at step  305 . The next step at  310  is to determine the amount of adjustment needed to provide the desired change in vehicle attitude (frequently this is the maximum). The next step  315  is to adjust the adjustable supports by the amounts determined in step  310  and the process is stopped in step  320  when the adjustments have been made. 
         [0030]    The attitude  551  of the chassis  125  is the angle of the plane  550  of the chassis  125  relative to the horizontal plane  554  and the attitude or slope  552  of the ground or terrain  120  is the angle of the plane  555  of the ground  120  relative to the horizontal plane  554  ( FIG. 5B ). 
         [0031]      FIG. 4  and  FIGS. 5A-5B  illustrate application of the method  300  of  FIG. 3  to the vehicle  100  traveling on a path  405 . The path  405  leading from the bottom  410  of a hill  402  up and along the side  420  of the hill  402  may be done r manually determined by the driver through observation of the surroundings or through interpretation of the surroundings by another occupant  140  of the vehicle  100 . In approaching the hill  402 , the path of travel  405  of the vehicle  100  extends over horizontal or level ground or terrain  120 . The adjustable supports  110  of the vehicle  100  are adjusted to be of equal height and, for example, at minimum level or height. As a result, the attitude  551  of the chassis  125  is substantially zero degrees and the plane  550  of the chassis  125  is substantially parallel to the plane  554  of the level or horizontal ground or terrain  120  (at  440  in  FIG. 4  and as shown in  FIG. 5A ). 
         [0032]    The attitude  552  of the ground  120  underneath the path  405  does not remain at zero degrees. Instead, the attitude  552  of the ground  120  underneath the path  405  changes from zero degrees at the base  410  of the hill  402  to an angle corresponding to the slope or attitude  552  of the side  420  of the hill  402  as the path  405  circles about the side  420  of the hill  402 . That is, the plane  550  of the chassis  125  with adjustable supports  110  equal in height acquires the attitude  552  of the ground  120  underneath the path  405  path, changing from a horizontal plane  554  to a plane inclined at the angle of the side  420  of the hill  402  relative to the horizontal plane  554   
         [0033]    The occupant  140  of the vehicle  100  within the cab  160  through observation determines the path  405  of the vehicle  100 , selecting from among alternative routes, and determines the manner in which the slope or attitude  552  of the ground  120  underneath the path  405  changes as the path  405  proceeds about the hill  402  (at  440  in  FIG. 4  and at Step  305 ). The occupant  140  determines that the path  405  climbs upward and that the attitude  552  of the ground  120  increases as the slope of the path  405  conforms to the slope of the hill  402 . 
         [0034]    To traverse the selected or determined path  405  in a more stable manner, the occupant  140  of the vehicle  100  adjusts the adjustable supports  130 . Adjustment of the adjustable supports  130  may be done manually by the occupant  140  of the vehicle  100  or manually through use of the controller  135  from the cab  160  of the vehicle  100 . 
         [0035]    In the case of the vehicle  100  shown in  FIG. 4 , the occupant  140  causes the downhill or down slope side  425  ( FIG. 5B ) of the vehicle  100  to be raised to its maximum height setting by inflating the airbags  110  on the right hand side  425  of the vehicle  110  and causes the uphill or up slope side  430  of the vehicle  100  to be lowered to its minimum height setting by, for example in the situation of  FIG. 4 , deflating the airbags  110  on the left hand side  430  of the vehicle  100  to the minimum height (at  450  in  FIG. 4  and as shown in  FIG. 5B ). In this manner, the attitude  551  of portion  125  of the vehicle  100  is reduced as the plane  550  of the chassis  125  is made more level with the horizontal plane  552  as the vehicle  100  follows the path  405  around the side  420  of the hill  402  (at  460  in  FIG. 4  and as shown in  FIG. 5B ). Thus, a fully adjustable independent suspension, such as pneumatic, hydraulic, and the like, with significant ride height adjustment capabilities can be provided, so that it is possible to lower the uphill side of a vehicle to its lowest ride height setting, while simultaneously raising the downhill side of the vehicle to its maximum ride height setting based on input from the driver, or a person assisting the driver or a vision system as described in the next paragraph. 
         [0036]    The present invention can also be used together with a vision system that looks at and analyzes the upcoming terrain before such terrain is actually reached so that the necessary adjustments for terrain can be made. 
         [0037]    The content of pending application Ser. No. 11/850,385 filed Sep. 5, 2007, and its parent application Ser. No. 11/430,771 filed May 9, 2006 are hereby incorporated herein by reference. They disclose some of the structure and method which may be used to increase the ability of the vehicle to increase its side slope operating capabilities for the present invention. 
         [0038]    Although the invention has been described with respect to various embodiments, it should be realized that this invention is also capable of a wide variety of further and other embodiments within the spirit and the scope of the appended claims.