Abstract:
A vehicle trajectory visualization system capable of displaying real-time (or recorded) vehicle orientation, position, velocity, and waypoint data using a 3D rendering system. The aforementioned data is transmitted from the vehicle to a base station that processes and manipulates the data prior to 3D rendering and insertion into a database. Due to the storing of the vehicle trajectory data, playback of past trajectories is possible, enabling enhanced visual After-Action Review. This system provides instant visual inspection of any virtual or real vehicle&#39;s planned trajectory and waypoints versus actual traveled trajectory.

Description:
BACKGROUND OF THE INVENTION 
     In the process of watching the planned operations of a vehicle (e.g. unmanned) as it flies, drives, burrows, floats, or maneuvers through a medium, it is difficult to ensure the vehicle remains on the planned path and sequences the waypoints correctly. Without a visualization system to view the planned versus actual trajectory, waypoints and other information regarding vehicle operations, one cannot accurately determine whether the vehicle meets the desired requirements. As the vehicle travels out of sight, it becomes more difficult to evaluate the desired vehicle travel trajectory effectiveness (waypoint time of arrival, deviations from plan, etc.). Vehicle waypoints are difficult for people to visualize, as are vehicle trajectories. 
     Therefore, there exists a need for a visualization system that tracks vehicle position, orientation, and velocity, shows planned versus actual trajectory, visualizes waypoints and waypoint sequencing, etc. with real-time and playback capability, thus allowing developers and trainers alike to perform After-Action Review (AAR), train in vehicle usage, track trajectory, and determine if requirements are met. 
     SUMMARY OF THE INVENTION 
     The present invention visually provides real-time vehicle trajectory information. It also provides a display of the vehicle planned travel trajectory with waypoints, After-Action Review of planned versus actual vehicle trajectory by visually inspecting historical missions, and the ability to replay logged vehicle telemetry and missions. 
     In one aspect of the present invention, the system provides for visualizing vehicle current and historical position, orientation, and velocity using real-time transmission of data from a vehicle. 
     In another aspect of the present invention, a 3D rendering system is provided for comparing planned versus actual vehicle trajectories. 
     In still another aspect of the present invention, data received from the vehicle is logged in a database for replay in the 3D rendering system. 
     In yet another aspect of the present invention, a visualization of the vehicle track is generated by a real-time virtual simulation. 
     Other objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  is a schematic diagram of an example system formed in accordance with the present invention; 
         FIG. 2  is a screen shot of a top down view of a vehicle operation scenario displayed according to an embodiment of the present invention; 
         FIGS. 3A  and B are screen shots of rendered video images from different viewpoints for a vehicle operation scenario according to an embodiment of the present invention; 
         FIG. 4  is a zoomed view of features presented for display according to an embodiment of the present invention; 
         FIG. 5  is a screen shot of a side view of a rendered video image of an air combat scenario according to an embodiment of the present invention; and 
         FIG. 6  is a functional representation of the system shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Aspects of the present invention provide systems and methods for displaying real-time vehicle orientation, position, and velocity information, as well as planned waypoint markers and past trajectory information. 
     Although the following disclosure will make reference to specific wireless transmission protocols and rates, 3D rendering system details, and database operation information, other comparable data communication methods and systems may be used. Particular configurations and protocols discussed in examples can be varied and are merely cited to illustrate an embodiment of the present invention and are not intended to limit the scope of the invention. 
       FIG. 1  shows a vehicle trajectory visualization system  20  that performs real-time monitoring and presentation of a vehicle&#39;s trajectory and evaluation of its waypoint sequencing correctness. The system  20  includes a vehicle  22  in signal communication with the base station  24 . The vehicle  22  includes sensors  30  and a database  32 . The base station  24  includes a processor  40  in signal communication with a database  42 , a display  44  and a user interface (UI)  46 . The base station  24  outputs a three-dimensional (3-D) presentation of vehicle operation on the display  44  based on information stored in the database  32  and generated by the sensors  30 . 
     The sensors  30  output sensed orientation, position, and velocity information. The database  32  includes previously stored waypoint data (3-D data). The vehicle  22  includes a communication component  34  that packages and sends the waypoint data and the sensor information to the base station  24  at a predetermined transmission rate (i.e. 30 Hz) using a predefined wireless communication protocol, such as IEEE#802.11b. The processor  40  applies various coordinate transformation calculations to prepare the received data for 3-D rendering and display on the display  44 . For example, the processor  40  receives universal transverse mercator (UTM), geodetic, etc., coordinates and transforms them into a 3-D rendering coordinate system. In addition, the processor  40  prepares the received data for insertion into the database  42  for later retrieval. 
     As shown in  FIGS. 2 ,  3 A and  3 B, the processor  40  presents images that include 3-D waypoint icons  100  that correspond to stored waypoint location information. Also, the processor  40  generates connecting lines  102  that connect successive waypoint icons  100 , thus providing a visual indication of the vehicles intended trajectory. 
     As the vehicle  22  travels in the real environment, the processor  40  generates and displays a series of breadcrumb icons  110  with connecting lines  112  based on the vehicle orientation, position, and velocity information received from the vehicle  22 . The breadcrumb icons  110  and connecting lines  112  indicate the vehicle&#39;s actual trajectory. The breadcrumb icons  110  are presented at predefined distance or time intervals. 
       FIG. 4  illustrates a zoomed-in view of a portion of a displayed breadcrumb icon  110  with connecting lines  112 . A vehicle velocity vector icon  118  is also presented with a start point at the center of the breadcrumb icon  110  and pointing in the direction in three-dimensional space that indicates the vehicle&#39;s actual velocity vector at that instant in time based on the velocity information received from the vehicle  22 . 
     In another embodiment, terrain and obstacles are generated and displayed in order to more accurately represent the environment in which the vehicle  22  is operating. The terrain and obstacle images presented on the display  44  are generated by the processor  40  based on information stored at either the vehicle database  32  or the base station database  42 . 
     When a user manipulates the user interface  46  in a change viewpoint mode, the processor  40  changes the viewpoint of the image that is presented. Also, multiple viewpoint images may be presented at the same time. For example, as shown in  FIGS. 3A and 3B ,  FIG. 3A  shows a viewpoint from the right side of the vehicle  22  and slightly above the horizon from the vehicle  22 .  FIG. 3B  has the viewpoint much closer to the vehicle  22 , but behind the vehicle  22 . 
     In one embodiment, vehicle waypoints are programmed in the vehicle  22  in terms of a relative or world coordinate system (i.e. latitude, longitude, and altitude) and sequence. The visually rendered and recorded vehicle trajectories between these waypoints aid in evaluating planned trajectories (lines  102 ) versus actual vehicle trajectories (lines  112 ). A calculated trajectory path  120  is generated by the processor  40  to visually represent a calculated vehicle trajectory based on known environmental conditions and vehicle control dynamics. For example, terrain, obstacle and weather information is stored in either or both of the databases  32 ,  42  and vehicle control dynamics are used by the processor  40  to determine the path  120  based on predefined threshold requirements, such as vertical and horizontal clearances and speed and turning limitations. This improves testing vehicle performance allowing observers to view overshoots and unplanned reactions to environmental conditions. It is also possible to visualize the calculated trajectory path  120  by extracting vehicle control loop responses from vehicle control dynamics (see  FIG. 6 ). This is beneficial when comparing various control loops within the vehicle to determine which algorithm is in control of a vehicle at any given time. 
     Referring to  FIG. 5 , trainers can perform training and after-action review for a trainee on a new vehicle.  FIG. 5  shows a visual display of a trainee vehicle  200  after engaging in a dog fight with the trainer/enemy vehicle  202 . In the after-action review, the trainers can review and show the trainee where the loss of target occurred and use it to show what actions could have been taken to improve performance in the future. 
     In one embodiment, the vehicle trajectory information is stored in the vehicle database  32  or the base station database  42 . The stored information is transmitted to the base station  24  using either the same remote communications medium or any other acceptable medium. The base station  24  then processes the received data as it would the data received from the vehicle  22  in real-time. The processed data is then displayed by the 3D rendering system. 
       FIG. 6  presents a notional functional representation of the vehicle  22  and the base station  24 . The vehicle  22  includes a control loop (a linear feedback system), which includes sensors  31 , control algorithms  33 , and actuators or servos  35 . In certain systems, the vehicle is either unstable enough or there is a collision avoidance system that requires more than one control algorithm  33  to be active. In that case, the control algorithms  33  are combined into a single response or are compared and the best solution is used. 
     When stating “extracting vehicle control loop responses from vehicle control dynamics,” it is with the intent of extracting the commanded position/orientation from the various control algorithms  33  in order to display the various calculated trajectories  120  in the 3D graphical display  55 . This is done by the vehicle  22  extracting the various calculated trajectories  120  from the control algorithms  33  and the actual trajectory  112  from the sensor data  31  and preparing the data for output extraction  37  through a wireless connection  50  to the base station  24 . On the base station  24 , the data is received, coordinate transformations of the received data are performed and the data is logged by the coordinate transformation function  53 . Then, the data is displayed in the 3D graphical display  55 . This is one instantiation of the calculated trajectory  120 . 
     Another instantiation of the calculated trajectory  120  is also represented in the notional functional design in  FIG. 6 . The calculated trajectory  120  is displayed in the 3D graphical display  55  after coordinate transformations are performed. The coordinate transformation function  53  performs coordinate transformations of the received data using a resident control loop. The resident control loop generates a dynamic “plant” model of the vehicle using mass and aerodynamic properties (a 6DOF model)  49 , sensor models (data)  45 , data of waypoints from the database  42 , data produced by a control algorithm  43 , and data from known or estimated environmental components  47 . The data from the environmental components  47  may include wind, air data, etc. There are two potential sources for the environmental components: on board vehicle sensors (ie. wind estimator, air data sensor, etc.) or weather station when on board sensors are not present on the vehicle  22 . The telemetry data outputted by the 6DOF model  49  is sent to output  51  then to the coordinate transformation function  53 . The coordinate transformation function  53  performs coordinate transformations and sends the data to be logged in the database  42 . Then the data is displayed in the 3D graphical display  55 . 
     For both instantiations, the data is logged in the database  42 . Performance analysis  41  can be performed on the data post-run or during the actual flight on a separate threaded process, thereby allowing real-time processing and display of the telemetry during the flight of the vehicle  22 . Performance analysis allows the comparison of calculated trajectories  120 , the planned trajectory (lines  102 ), and the actual trajectory (lines  112 ). 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.