Abstract:
Parking assistance is provided to a driver by shifting the viewing perspective of cameras attached to the vehicle. Shifting the perspective is accomplished by capturing images of objects adjacent the vehicle to be parked, determining distances between the vehicle and objects adjacent the vehicle, creating a three-dimensional map of objects adjacent the vehicle, overlaying images of objects adjacent the vehicle onto the three-dimensional map, and creating a virtual three-dimensional representation of objects adjacent the vehicle.

Description:
BACKGROUND 
       [0001]    Parking a vehicle is a challenge for some drivers. Some vehicle manufacturers provide rear-facing cameras, which can help with parking but their true value is limited primarily because they do not provide a spatial point of reference. Stated another way, they do not provide a perspective of objects adjacent the vehicle, which often make it difficult to park a car. A method and apparatus for assisting a driver with parking a car would be an improvement over the prior art. 
       BRIEF SUMMARY 
       [0002]    In accordance with embodiments of the invention, parking assistance is provided to a driver by shifting the viewing perspective of cameras attached to the vehicle. Shifting the perspective is accomplished by capturing images of objects adjacent the vehicle to be parked, determining distances between the vehicle and objects adjacent the vehicle, creating a three-dimensional map of objects adjacent the vehicle, overlaying images of objects adjacent the vehicle onto the three-dimensional map, and creating a virtual three-dimensional representation of objects adjacent the vehicle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a side view of a vehicle, namely an automobile; 
           [0004]      FIG. 2  is a top view of the vehicle shown in  FIG. 1 ; 
           [0005]      FIG. 3  is a block diagram of an apparatus for providing shifted perspective parking assistance; 
           [0006]      FIG. 4  is an illustration of a shifted perspective to two vehicles adjacent to each other; and 
           [0007]      FIG. 5  is a block diagram showing steps of a method for shifting the perspective of a parking camera. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]      FIG. 1  is a side view of a vehicle  100 . The vehicle  100  has a front end  102  and a rear end  104 . It also has a front bumper  106  and a rear bumper  108 . 
         [0009]      FIG. 2  is a top or plan view of the automobile  100  shown in  FIG. 1 . The front end  102  of the vehicle  100  has several cameras  202 ,  204 ,  206  and  208 . The rear end  104  of the vehicle  104  is also provided with several cameras  210 ,  212 ,  214  and  216 . 
         [0010]    As used herein, the term “field of view” refers to an area or region captured by an imager in each camera. Each camera has a field of view  240 . The combined fields of view of the cameras at the front  102  subtend an angle of about one-hundred eighty degrees relative to a longitudinal axis  242 , as do the cameras at the rear  104 . The cameras thus capture images of objects around or adjacent the vehicle, specifically including objects in front of and behind the vehicle. 
         [0011]    As is well known, many cameras employ an ultrasonic distance sensor to focus the camera lens and adjust a flash unit. In a preferred embodiment each camera  202 ,  204 ,  206 ,  208  attached to the front  102  of the vehicle  100  is provided with a corresponding ultrasonic distance sensor  218 ,  220 ,  222  and  224 . The cameras  210 ,  212 ,  214  and  216  at the rear end  104  are also provided with corresponding ultrasonic distance sensors  226 ,  228 ,  230  and  232 . 
         [0012]    The distance sensors determine and provide a measurement of the distance between themselves and an object within a field of view  240  of a corresponding camera. In other words, a first camera  202 , at the right front of the vehicle  102  has a distance sensor  218 , which determines distances between the distance sensor  218  or camera  202  and objects within the field of view  240  of the camera  202 . Similarly, the camera  210  at the left rear bumper of the vehicle has a distance sensor  226 , which determines distances between the distance sensor  226  and camera  210  and objects within the field of view  240  of the camera  210 . Together, the distance sensors determine distances between the vehicle  100  and objects around, i.e. adjacent, the vehicle  100 . 
         [0013]    As used herein, the term, “adjacent” means mean in close proximity to. An object is or can be adjacent to a vehicle to be parked, if the object is in front of, behind, next to, or otherwise in close proximity, such that the separation distance between the object or a portion or surface thereof, and a vehicle to be parked is less than about ten feet up to as much as about twenty to thirty feet, depending on the size of the vehicle to be parked. 
         [0014]    As used herein, “perspective” refers to the appearance of objects in respect to their relative distances from each other and their positions, relative to each other.  FIG. 3  is a block diagram of an apparatus  300  for providing parking assistance by shifting the perspective of the cameras  202 - 216  and for providing on a display device, one or more images representing a view of the vehicle from the perspective of an object around the vehicle, i.e., adjacent to the vehicle, an image of which is captured by a camera, the distance from the vehicle of which is measured by a distance sensor. The terms, “around” and “adjacent” are used interchangeably hereinafter. 
         [0015]    As used herein, the term “bus” refers to a set of electrically-parallel conductors in a computer system and which form a main transmission path for components of the computer system. The system  300  in  FIG. 3  comprises multiple cameras  302 ,  304  and  306  each of which is coupled to a bus  308  preferably embodied as a controller area network or “CAN” bus that couples the cameras to a controller  310 , i.e., a processor  310 . The cameras  302 ,  304  and  306  capture images of objects within their corresponding fields of view  322  responsive to commands that they receive from the controller  310 . The cameras, which are digital, provide data via the bus  308  to the controller  310 , which represent captured images of objects within the corresponding fields of view. By virtue of the placement of the cameras on the vehicle, the cameras are thus able to capture images of objects around the vehicle. 
         [0016]    The system  300  additionally comprises a distance sensor associated with each camera. The distance sensors  316 ,  318  and  320  ultrasonically measure or determine distances between themselves, each of which is attached to the vehicle, and objects within the fields-of-view  322  of the corresponding cameras. 
         [0017]    The ultrasonic distance sensors  316 ,  318  and  320  are also coupled to the controller  310  via the same bus  308 . The distance sensors, by virtue of their physical and operational association with cameras, determine distances between objects around the vehicle and are able to thus create a three-dimensional mapping of objects around the vehicle. The distance sensors are used to create a three-dimensional mapping of objects around the vehicle and their locations from the vehicle. 
         [0018]    The controller  310  is coupled to a non-transitory memory device  312  through a second bus  314 , commonly referred to as an address/control/data bus, commonly used in microcontroller and microprocessor computer based systems. Program instructions in the non-transitory memory device  312  cause the processor to overlay the locations of the objects around the vehicle onto the images of objects captured by the cameras  302 ,  304  and  306  and thus create a virtual three-dimensional representation of objects around the vehicle  100 . 
         [0019]    Program instructions in the memory device  312  cause the processor  310  to “create an image” of the virtual three-dimensional representation of objects around the vehicle. That image is displayed on a touch-sensitive display device  324  located in the control panel or dashboard  326  of the vehicle  100 , which is omitted from  FIG. 3  for brevity and clarity. The image displayed on the display device  324  is thus an image of objects around the vehicle  100  that a person would see when the vehicle  100  is viewed from the perspective of one of the objects detected by the distance sensors and “seen” by a corresponding camera. 
         [0020]      FIG. 4  illustrates a shifted perspective view  400  of a vehicle to be parked  402  and which is in front of a vehicle that is already parked and stationary  404 . The second vehicle  404  is also an object that is around, i.e., adjacent to, the vehicle  402  to be parked. Cameras and distance sensors on the first vehicle  402  detect an object  406  away from the vehicle  402  and project on a display device an image of the two vehicles. The view of the two vehicles is shifted in space to a point in an x-y plane and with a horizontal rotation angle, Θ. 
         [0021]    The ability to provide an image of objects adjacent to the vehicle  100  inherently requires a three-dimensional model of surfaces and dimensions of the vehicle  100  to which the cameras and distance sensors are attached. Knowing those dimensions and surface models enables the controller  310  to render on the display device  324  a virtual image of the vehicle  100  on the display device that appears to be a three-dimensional model. The rendering of a second vehicle on the display device  324  is facilitated by models of surfaces of generic vehicle characteristics, selected by the controller  310  responsive to program instructions stored in the non-transitory memory device  312 . 
         [0022]      FIG. 5  depicts steps of a method of providing vehicle parking assistance. More particularly,  FIG. 5  depicts steps of a method to shift the perspective of a parking camera. 
         [0023]    As a first step  502 , the method requires the capture of images of objects around or adjacent a vehicle, using an apparatus such as the one described above. Those of ordinary skill in the art will recognize the necessity of limiting the distance or range of objects images of which are to be captured. By way of example, images that are more than 3-10 feet from the front and rear bumpers, are ignored. 
         [0024]    At step  504 , the actual distances between the vehicle surfaces and objects around the vehicle and in the field of view of a camera are determined using ultrasonic distance sensors. Once those distances are determined, the locations of those objects around the vehicle are “mapped” in step  506  by their spatial coordinates. The spatial coordinates are x and y coordinates in a horizontal plane in which the vehicle lies. 
         [0025]    At step  508 , the images of objects captured by the cameras are overlaid onto the map or the locations of those objects detected by the ultrasonic sensors. At step  510 , a rendering or drawing of a three-dimensional representation of those objects in space is prepared and at step  512 , the three-dimensional rendering is displayed on a two-dimensional display device. The image displayed on the display device is a view of the vehicle from the perspective of a point in an x-y coordinate plane, in which the vehicle lies, with a specified horizontal rotation angle, from the perspective of that point in space the result of which is a shifted perspective of the vehicle to be parked as shown in  FIG. 4 . 
         [0026]    As used herein, the term “real time” refers to an actual time during which something takes place. Those of ordinary skill in the art will recognize the importance of rendering a shifted perspective of a parking camera in real time. The method described above and the apparatus depicted in  FIG. 3  thus provide a real-time rendering of a parked object and a vehicle to be parked viewed from the perspective of a point located in an x-y coordinate plane in which the vehicle lies with a horizontal rotation angle that enables or provides on an instrument-panel mounted display device, a view of objects in front of and behind a vehicle to be parked. 
         [0027]    The foregoing description is for purposes of illustration only. The true scope of the invention is set forth in the following claims.