Abstract:
Systems and methods are disclosed to assist a driver with a dangerous condition by creating a graph representation where traffic participants and static elements are the vertices and the edges are relations between pairs of vertices; adding attributes to the vertices and edges of the graph based on information obtained on the driving vehicle, the traffic participants and additional information; creating a codebook of dangerous driving situations, each represented as graphs; performing subgraph matching between the graphs in the codebook and the graph representing a current driving situation to select a set of matching graphs from the codebook; determining a distance metric between each selected codebook graphs and the matching subgraph of the current driving situation; from codebook graphs with a low distance, determining potential dangers; and generating an alert if one or more of the codebook dangers are imminent.

Description:
[0001]    This application claims priority to Provisional Application 62/146,565, filed Apr. 13, 2015, and this application is a divisional of application Ser. No. 15/088,494, filed Apr. 1, 2016, the content of which is incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to systems and methods for long term automotive danger prediction. 
         [0003]    In this age of increasing driving distractions, drivers are ever more likely to fail to recognize potential danger in complex driving situations. Collision avoidance systems are becoming common in cars. These systems apply the brakes when the driver fails to notice obstacles at close range. These systems operate in a short time range and are mostly reactive. However, these systems do not predict danger on a longer time horizon, nor focus on the driver&#39;s attentiveness. 
       SUMMARY 
       [0004]    In one aspect, systems and methods are disclosed to assist a driver with a dangerous condition by combining several sensor modalities available on modern cars to detect traffic participants as well as static elements; creating a graph representation where traffic participants and static elements are the vertices and the edges are relations between pairs of vertices; adding attributes to the vertices and edges of the graph based on information obtained on the driving vehicle, the traffic participants and additional information; creating a codebook of traffic situations known to be precursors to dangerous situations, each represented as graphs; performing subgraph matching between the graphs in the codebook and the graph representing a current driving situation to select a set of matching graphs from the codebook; determining a distance function between each selected codebook graphs and the matching subgraph of the current driving situation; from codebook graphs with a low distance, determining potential future dangers; and generating alerts to the driver appropriately. 
         [0005]    Advantages of the system may include one or more of the following. The system helps drivers who are ever more likely to fail to recognize potential danger in complex driving situations. The system provides long range (several seconds) advance warning for dangerous driving situations. In contrast, existing system are collision warning that simply react to the presence of an obstacle directly ahead of the vehicle by applying the brakes. Long range warnings about impending dangerous driving situations could lead to a reduction in accidents. Collision warning systems provide an added security, however they can only be engaged at the last moment, when it is often too late. By identifying a dangerous situation ahead of time, the system has time to warn the driver or slow down the vehicle over a longer period of time, avoiding sudden evasive maneuvers which are inherently dangerous. The system can improve the safety of driving a car by predicting the occurrence of dangerous driving situations up to several seconds ahead of time. The system provides an added level of safety for driving cars and can also be used in autonomous cars. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  shows an exemplary system architecture for danger prediction. 
           [0007]      FIG. 2  shows an exemplary automotive computing system. 
           [0008]      FIG. 3  shows an exemplary operation of the system. 
       
    
    
     DESCRIPTION 
       [0009]    Referring now to the drawings in which like numerals represent the same or similar elements and initially to  FIG. 1 , an exemplary process for assisting driver is presented. 
         [0010]    The process captures input from hardware such as radar, video, GPS, street map, driver-status, traffic and weather information and combines it to represent a driving situation in a top-view 2D representation containing a graph of static elements (road, signs, etc.) and traffic participants. The GPS unit of the car is used to position the driving vehicle on a street map that contains information about roads, intersection, etc. The radar module detects and tracks the position and velocities of a number of objects relative to the driving car. These objects (position and velocities) are then placed on a top view two-dimensional representation. Video information may be used to improve the accuracy of the positioning by using lane detection or structure from motion. In addition, the video may be used to recognize the type of objects (car, pedestrian, static obstacle) found by the radar. Furthermore it may also be used to recognize traffic signage. 
         [0011]    The top-view 2D representation is then converted into a combined graph representation where vertices are the traffic participant (TP) as well as the static elements (SE) and the edges represent the relations between pairs of TP/SEs. Vertices and edges contain attributes describing their nature and characteristics. Vertices attributes may contain the type of object it represents (e.g. car, truck, pedestrian, etc.), intrinsic parameters (e.g. physical characteristics of cars, width of road lanes, mental status of driver, etc.), and also global information (e.g. weather, traffic, etc.). Edges attributes typically contain relations such as action types (e.g. ‘driving on’, ‘approaching’, etc.), relative position, speed and acceleration. Attributes can be either actual values or ranges of values. Such top-view 2D graph representations are compact and well suited for comparison and queries. 
         [0012]    Next, potential dangerous driving situations are analyzed. Such situations may originally be described in police reports, driver&#39;s permit booklets, in naturalistic driving datasets (e.g. SHRP2) or also from common sense driving knowledge. Transcribing this knowledge into a codebook of dangerous driving situation is a one-time manual step. 
         [0013]    Let&#39;s follow an example to illustrate the process. Starting with the following common sense description: “When driving on the passing lane on a highway, you must watch out for cars cutting you off while attempting to pass, in particular you can anticipate this by watching for cars going faster than the car in front of them”. The following graph encodes the situation: 
         [0014]    Static elements (vertices): 
         [0015]    SE1: highway lane #1 
         [0016]    SE2: highway lane #2 (passing lane) 
         [0017]    Traffic Participants (vertices): 
         [0018]    DC: driving car 
         [0019]    TP1: car ahead on lane 
         [0020]    TP2: car ahead of TP1 
         [0021]    Relations (edges): 
         [0022]    DC-SE2: driving on lane 
         [0023]    TP1-SE1: driving on lane 
         [0024]    TP2-SE1: driving on lane 
         [0025]    DC-TP1: relative position: ahead, less than 100 m, to the right 2 to 3 m; relative speed: forward negative 
         [0026]    TP1-TP2: relative position: ahead, less than 100 m; relative speed forward negative 
         [0027]    The process of matching the encoded situation to the current driving situation is performed using subgraph matching techniques. Once possible candidate situation have been identified, a distance function is used to evaluate how close the current situation is to the candidate codebook situations. Thresholds are defined so that alerts can be triggered when the current driving situation is deemed close to one or more of the codebook situations. 
         [0028]    Coming back to the example, the current driving situation of  FIG. 3  is encoded into a graph. There is not an exact match with the codebook situation described above; however subgraph matching successfully identifies a subgraph of the current driving situation that is an exact match. The next step is to measure how close a match the two situations are based on the attributes of the graph vertices and edges. In this case the positions and velocities of the TPs are close, so the distance calculation returns a small value and because it is below threshold, a warning is activated. 
         [0029]    The distance function is calculated using the attributes of two subgraphs which structures have been matched. We are contemplating various implementation of this distance function. In one embodiment, the attributes of subgraphs can be compared using a trained classifier that has learned to output a distance value based on supervised machine learning. Such classifiers could be trained independently for each codebook entry, or globally, based on attributes statistics (such that the input feature vectors to a classifier have matching length). Supervised learning techniques such as SSI are well suited to train such classifiers with alternating pairs of positive and negative examples. In another embodiment, the distance function between a pair of subgraphs is defined manually based on certain attributes, so that each codebook situation comes with its own distance function. In a third embodiment, a generic distance function is defined that checks each attribute against a range of acceptable values encoded in the codebook situations. These ranges may have been obtained either manually by direct observation or through unsupervised learning techniques, such as clustering using recorded driving datasets. 
         [0030]    Turning now to  FIG. 1 , GPS and map data is used to build a local 2D map view  10 . Radar and video data is used to synthesize a 3D model  14 , while video data is used to recognize object types  18 . From the foregoing, the process creates a map view  34  with TPs  30 . A graph is created in  38 . The graph receives data such as driver status, weather status, traffic status, and car attributes and updates the graph in  40 . The data is used to train codebook attributes in  44 . Together with human knowledge, a codebook is formed in  46 . The graph is matched to the codebook in  48 , and subgraphs are generated in  50 . The process determines subgraph distance in  52 , and inter-vehicle distances are determined in  54 . If too close, an alarm is generated in  60 . 
         [0031]    Referring now to  FIG. 2 , an exemplary car processing system  100 , to which the present principles may be applied, is illustratively depicted in accordance with an embodiment of the present principles. The processing system  100  includes at least one processor (CPU)  104  operatively coupled to other components via a system bus  102 . A cache  106 , a Read Only Memory (ROM)  108 , a Random Access Memory (RAM)  110 , an input/output (I/O) adapter  120 , a sound adapter  130 , a network adapter  140 , a user interface adapter  150 , and a display adapter  160 , are operatively coupled to the system bus  102 . 
         [0032]    A first storage device  122  and a second storage device  124  are operatively coupled to system bus  102  by the I/O adapter  120 . The storage devices  122  and  124  can be any of a disk storage device (e.g., a magnetic or optical disk storage device), a solid state magnetic device, and so forth. The storage devices  122  and  124  can be the same type of storage device or different types of storage devices. 
         [0033]    A speaker  132  is operatively coupled to system bus  102  by the sound adapter  130 . A transceiver  142  is operatively coupled to system bus  102  by network adapter  140 . A display device  162  is operatively coupled to system bus  102  by display adapter  160 . 
         [0034]    A first user input device  152 , a second user input device  154 , and a third user input device  156  are operatively coupled to system bus  102  by user interface adapter  150 . The user input devices  152 ,  154 , and  156  can be any of a keyboard, a mouse, a keypad, an image capture device, a motion sensing device, a microphone, a device incorporating the functionality of at least two of the preceding devices, and so forth. Of course, other types of input devices can also be used, while maintaining the spirit of the present principles. The user input devices  152 ,  154 , and  156  can be the same type of user input device or different types of user input devices. The user input devices  152 ,  154 , and  156  are used to input and output information to and from system  100 . 
         [0035]    Of course, the processing system  100  may also include other elements (not shown), as readily contemplated by one of skill in the art, as well as omit certain elements. For example, various other input devices and/or output devices can be included in processing system  100 , depending upon the particular implementation of the same, as readily understood by one of ordinary skill in the art. For example, various types of wireless and/or wired input and/or output devices can be used. Moreover, additional processors, controllers, memories, and so forth, in various configurations can also be utilized as readily appreciated by one of ordinary skill in the art. These and other variations of the processing system  100  are readily contemplated by one of ordinary skill in the art given the teachings of the present principles provided herein. 
         [0036]    Further, it is to be appreciated that processing system  100  may perform at least part of the methods described herein including, for example, at least part of method of  FIG. 1 . 
         [0037]      FIG. 3  shows an exemplary operation of the system. In this hypothetical, a white car ahead is about to pass the truck and cut into the driving car&#39;s lane. On the right is the map representation of the traffic as obtained using radar, GPS and map. As an illustration of an action taken by the system, the yellow warning pops up before the white car starts changing lane. 
         [0038]    Embodiments may include a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. A computer-usable or computer readable medium may include any apparatus that stores, communicates, propagates, or transports the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be magnetic, optical, electronic, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. The medium may include a computer-readable storage medium such as a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk, etc. 
         [0039]    A data processing system suitable for storing and/or executing program code may include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code to reduce the number of times code is retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) may be coupled to the system either directly or through intervening I/O controllers. 
         [0040]    Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters. 
         [0041]    The foregoing is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that those skilled in the art may implement various modifications without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention.