Patent Publication Number: US-2012033078-A1

Title: Handling assistant apparatus for two-body connected vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §371 of PCT Patent Application Number PCT/US2010/29122, filed Mar. 30, 2010, and China Utility Application No. 200920008223.7, filed Mar. 30, 2009, the entire disclosure of which is hereby incorporated herein by reference. Furthermore, related application PCT/US10/28383, filed 24 Mar. 2010 is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to automobile parts, more particularly, relates to handling assistant apparatus for two-body connected vehicle. 
     BACKGROUND 
     The term two-body connected or articulated vehicle generally refers to Tractor—Trailer vehicles, which often have a large length more than 10 meters. A two-body connected vehicle is composed of a tractor and a trailer. Operation of a two-body connected vehicle is difficult, especially during reversing and parking the vehicle. The tractor and the trailer are connected through a rotatable joint and often have different turning radiuses, so the tractor and the trailer will have different moving tracks when reversing with turning. A driver can only operate the tractor. The moving orientation of the tractor is predictable and operable by the driver. However, the trailer can not be directly operated and the moving orientation can not be predicted by the driver. Crash or scrape accidents may happen on the trailer. 
     Backward vision cameras are used to facilitate the reversing of the vehicle. Backward vision cameras are widely used on signal-body vehicles and are proved to be successful. However, backward vision cameras have not obtained the expected effects on two-body connected vehicles. The difference between a two-body connected vehicle and a single-body vehicle is: the single-body vehicle has a single turning and moving track because it only has one body, the driver may predict the moving orientation of the vehicle through the backward camera and may adjust the moving orientation through operation of the vehicle. However, for a two-body connected vehicle, the tractor and the trailer have different turning or moving tracks, the observed moving orientation through the backward camera is the moving orientation of the trailer, not the tractor. On the other hand, only the tractor can be operated and only the moving orientation of the tractor can be directly adjusted. Therefore, what is observed by the driver is not directly corresponding to his operation, the operation of the driver can not be directly reflected on the change of the moving orientation of the trailer. Accidents may happen under such a condition. 
     SUMMARY 
     Embodiments of the present disclosure provide an apparatus which may intuitively reflect the relationship between the driver&#39;s operation and the moving track of the trailer. 
     According to an embodiment, a handling assistant apparatus for two-body connected vehicle is provided. The apparatus is applied to a two-body connected vehicle including a tractor and a trailer, the tractor and the trailer each having a different turn radius. A static signal acquisition means acquires static signals of the tractor and the trailer. The static signals include length signals of the tractor and the trailer and minimum turning radius signals of the tractor and the trailer. A moving orientation signal acquisition means acquires moving orientation signals of the tractor and the trailer. A video signal acquisition means acquires original video signals. An angle acquisition means is mounted at the joint point of the tractor and the trailer and acquires an angle signal between the moving orientations of the tractor and the trailer. A dynamic signal generation means generates dynamic signals of the tractor and the trailer based on the original video signals, the static signals of the tractor and the trailer, the moving orientation signals of the tractor and the trailer and the angle signal between the moving orientations of the tractor and the trailer. The dynamic signal reflects a prediction of the moving orientation and a position of the tractor and the trailer. A dynamic signal presentation means presents the dynamic signal. 
     According to an embodiment, the video signal acquisition means is a backward vision camera inclined at the top of the rear of the trailer. 
     According to an embodiment, the dynamic signal presentation means includes a video signal presentation means and a dynamic signal rendering means. The dynamic signal presentation means presents video signals acquired by the backward vision camera. The dynamic signal rendering means presents a prediction of the moving orientation and the position of the tractor and the trailer, converts the prediction from a real world coordinate to a pixel coordinate, and renders predicted lines indicative of the predicted moving orientation and position upon the video signals presented by the video signal presentation means. 
     The handling assistant apparatus for two-body connected vehicle may intuitively reflect the relationship between the driver&#39;s operation and the moving track of the trailer by rendering predicted lines. The accuracy of operation is raised and the possibility of accidents such as crash or scrape is reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above or other features, natures or advantages of the present disclosure will be more obvious to the skilled person in the art by the following descriptions of the embodiments accompanying with the drawings, the same sign reference indicates the identical features throughout the description, and wherein: 
         FIG. 1  illustrates a structural diagram of a handling assistant apparatus for two-body connected vehicle according to an embodiment of the present disclosure; 
         FIG. 2  illustrates a structural diagram of a static signal acquisition means according to an embodiment of the present disclosure; 
         FIG. 3  illustrates an exemplary static signal according to an embodiment of the present disclosure; 
         FIG. 4  illustrates a structural diagram of a dynamic signal generation means according to an embodiment of the present disclosure; 
         FIG. 5  illustrates an exemplary dynamic signal according to an embodiment of the present disclosure; 
         FIG. 6  illustrates a schematic prediction of moving orientation and position according to an embodiment of the present disclosure; 
         FIG. 7  illustrates a structural diagram of a dynamic signal presentation means according to an embodiment of the present disclosure; 
         FIG. 8  illustrates a schematic view of presentation of a dynamic signal according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG. 1 , a handling assistant apparatus  100  for two-body connected vehicle is disclosed. The handling assistant apparatus  100  includes: a static signal acquisition means  102 , a moving orientation signal acquisition means  104 , an angle acquisition means  106 , a video signal acquisition means  107 , a dynamic signal generation means or controller  108  and a dynamic signal presentation means  110 . 
     The static signal acquisition means  102  acquires static signals of the tractor and the trailer. The static signals include length signals of the tractor and the trailer and minimum turning radius signals of the tractor and the trailer. As shown in  FIG. 2 , according to an embodiment, the length signals  200  of the tractor and the trailer are acquired by a length acquisition means  202 , and the minimum turning radius signals of the tractor and the trailer are acquired by a static turning radius acquisition means  204 . 
     According to an embodiment, more static signals may be acquired, as shown in  FIG. 3 .  FIG. 3  illustrates a two-body connected vehicle or articulated tractor trailer  300 . 
     Wherein, 
     OA is the minimum turning radius of the tractor; 
     Point A is the middle point of the front axle of the tractor; 
     Point O is the assumed center point of the turn circle, Point O is the center point for the turn circle of both the tractor and the trailer; 
     Point M is the joint point or rotation axis of the tractor and the trailer; 
     Point B is the middle point of rear axle of the tractor; 
     Point G′ is the middle point of the rear bridge of the trailer (it is assumed that the trailer turns by the minimum turning radius); 
     OG′ is the minimum turning radius of the trailer along a turn circle centered by point O. 
     Then, 
         OG′= √{square root over (OA 2   −AB   2   +MB   2   −MG   2 )}.
 
     In  FIG. 3 , the angle between OA and OB is denoted as θ 1 , the angle between OM and OB is denoted as θ 2 , the angle between OM and OG′ is denoted as θ 3 . 
     It is assumed that the tractor  302  moves along line AB and the trailer  304  moves along line MG′. The moving orientation signal acquisition means  104  acquires moving orientation signals of the tractor and the trailer, that is the orientation of line AB and the orientation of line MG′ (it is assumed that the trailer turns by the minimum turning radius OG′). 
     The angle acquisition means  106  acquires an angle signal between the moving orientations of the tractor and the trailer.  FIG. 3  shows the condition that both the tractor and the trailer turn by their minimum turning radiuses. However, in an actual condition, it is impossible that the vehicle directly enters into such a condition (directly turns by the minimum turning radius). For example, when the tractor and the trailer are initially along a straight line, the tractor and the trailer can not enter a condition that turn by the minimum radius immediately even the driver turns the steering wheel to a maximum position, it need a period of time for the tractor and the trailer to enter the condition shown in  FIG. 3 . During the above period, since the tractor is directly operated by the driver, it may enter into the condition that turns by the minimum radius quickly. However, the trailer can not enter into the condition that turns by the minimum radius so quickly. The trailer will gradually increase its turning angle and gradually enter into the condition that turns by the minimum radius. During this period, the moving track of the trailer is not strictly along a circle having a radius of OG′ (shown in  FIG. 3 ), the moving track is an arc. For accurate prediction of this arc, the angle between the actual moving orientation of the tractor and the actual moving orientation of the trailer is utilized, the angle is shown as the angle between AB and MG′ in  FIG. 3 . The angle is measured by the angle acquisition means  106  in real time. The angle acquisition means  106  is mounted at the joint point of the tractor and the trailer, as denoted by point M in  FIG. 3 . The angle acquisition means may be a Hall sensor. 
     As described above, when the tractor and the trailer are along a straight line, or the tractor and the trailer both turn by their minimum turning radius, the moving tracks of the tractor and the trailer are fixed. However, during the period mentioned above, the trailer gradually enters into the condition that turns by its minimum turning radius from the initial status. During this period, the turning radius of the trailer is changing and shall be regarded as a dynamic turning radius. The dynamic signal generation means  108  predicts the moving track of the trailer during this period. The dynamic signal generation means  108  generate dynamic signals of the tractor and the trailer based on the original video signals acquired by the video signal acquisition means  107 , the static signals acquired by the static signal acquisition means  102 , the moving orientation signals acquired by the moving orientation signal acquisition means  104  and the angle signal acquired by the angle acquisition means  106 . The video signal acquisition means  107  may be implemented by a backward camera inclined at a particular height of the rear of the trailer, the acquired original video signals are video images behind the trailer. 
     According to an embodiment, the dynamic signal generation means  108  a moving orientation prediction means  402  and a position prediction means  404 . The moving orientation prediction means  402  generates moving orientation prediction signals of the tractor and the trailer based on the static signals, the moving orientation signals and the angle signal. The position prediction means  404  generates position prediction signals of the tractor and the trailer based on the static signals, the moving orientation signals and the angle signal. 
     According to an embodiment, more static signals may be acquired, as shown in  FIG. 5 . 
     θ 4  is an angle between the actual moving orientation of the tractor and the actual moving orientation of the trailer. The actual turning radius of the trailer is OG, not the minimum turning radius, because the trailer does not immediately turn by its minimum turning radius. In  FIG. 4 , θ 4  is the angle between AB and MG. 
     Point C is a joint point of MG and a vertical line from point O to MG, OC is perpendicular to MG, so the angle between OM and OC is θ 4 ; 
     Then, 
         OM= √{square root over (MB 2   +OA   2   −AB   2 )};
 
     MC=OM×sin θ 4 ; 
     OC=OM×cos θ 4 ; 
     CG=MG−MC; 
     
       
         
           
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     Based on the above data and signals, the dynamic signal generation means  108 , the moving orientation prediction means  402  and the position prediction means  404  predict the next movement of the vehicle, especially the next movement of the trailer. 
     Set point C′ as the original point, C′ is generally the position of the backward vision camera, a horizontal two-dimensional coordinate is utilized. 
     GD is a distance from the middle point of the rear bridge of trailer to the right edge of the trailer. Point D is the right edge of the trailer. 
     GE is a distance from the middle point of the rear bridge of trailer to the left edge of the trailer. Point E is the left edge of the trailer. 
     GC′ is a distance from the original point C′ (the position of the backward camera) to the middle point of the rear bridge. 
     C′R is a distance from the original point C′ (the position of the backward camera) to the rear edge of the trailer. Point R is the rear edge of the trailer. 
     Since the backward vision camera may observe the scene within a predetermined distance behind the trailer. It is assumed that a point P is placed within the observation range of the backward vision camera, the coordinate of point P in the coordinate system with the original point C′ is P(x, y). The distance from the point P to the rear edge of the trailer is “dist”. As shown in  FIG. 6 , only the distance along axle x is considered in “dist”, the distance along axle y is not considered. 
     At a next time, point P moves to point P′, the coordinate of point P′ is P′(x′, y′). The trailer turns an angle θ, which means the angle of the line defined by the middle point of the rear bridge and point O. Angle θ may be computed as follows: 
     θ=dist/OG, “dist” means both the distance from point P to the rear edge of the trailer, and the length of the arc passed by point G. Angle θ may be computed by the formulation above. 
         P ( x,y )=((dist+ GC+CR ), GD ) 
     Then, the coordinate P′(x′, y′) of point P′ is: 
         P ′( x′,y ′)=(( OG−GR )×sin θ+( GC+CR )×cos θ)− GC,OG ×(1−cos θ)+( GC+CR )×sin θ+ GR ×cos θ).
 
     Then the dynamic signal generation means  108  predicts the next position P′ of the reference point P. 
     After the moving orientation and the position are predicted based on the dynamic signals, the dynamic signal presentation means  110  presents the prediction based on the dynamic signals, so as to provide sufficient information to the driver. 
     As shown in  FIG. 7 , according to an embodiment, the dynamic signal presentation means  110  includes a video signal presentation means  702  and a dynamic signal rendering means  704 . The video signal presentation means  702  presents video signals acquired by the video signal acquisition means  107 . The video signal presentation means  702  may be implemented by a display. The dynamic signal rendering means  704  renders the dynamic signals generated by the dynamic signal generation means upon the video signals presented by the video signal presentation means. 
     According to an embodiment, the dynamic signal rendering means  704  includes an coordinate conversion means  740  for converting a real world coordinate to a pixel coordinate and a predicted line generation means  742  for generating predicted lines based on the moving orientation prediction signals and the position prediction signals. 
       FIG. 8  illustrates a schematic view of presentation of a dynamic signal according to an embodiment of the present disclosure. The backward vision camera  800  (an implementation of the video signal acquisition means is raised to a height h with an inclined angle p. The coordinate used for prediction is a two-dimensional coordinate (x, y). The coordinate used by the backward vision camera is a three-dimensional coordinate (x′, y′, z′). It is assumed that the coordinate (x, y) used for prediction is set at a position with a distance f from the backward vision camera. A corresponding coordinate P(x, y, z) of the point P and a corresponding coordinate P′(x′, y′, z′) of the prediction position P′ in the three-dimensional coordinate may be obtained by existing conversion algorithm. The conversion algorithm shall be known in prior art and is not concerned by the present disclosure, the conversion algorithm is not described in detail here. 
     Therefore, the conversion from a real world coordinate to a pixel coordinate is accomplished. After obtaining the pixel coordinates of point P and the prediction point P′, the predicted lines may be rendered by using the pixel coordinates of point P′. Then a predicted moving track of the trailer may be rendered upon the video signals presented by the video signal presentation means. 
     The handling assistant apparatus for two-body connected vehicle may intuitively reflect the relationship between the driver&#39;s operation and the moving track of the trailer by rendering predicted lines. The accuracy of operation is raised and the possibility of accidents such as crash or scrape is reduced. 
     The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.