Perspective view conformal traffic targets display

A system and method for displaying traffic targets in a conformal perspective view. The system comprises a display screen for graphical display of data, one or more sensors for obtaining traffic data regarding traffic targets, and one or more processors for receiving traffic data from the one or more sensors and providing input to the display screen. The display screen displays traffic targets as icons in a 3-dimensional graphical representation of real space. The display size of the icons is selected from a finite set of sizes which correspond to a finite set of distance ranges based on the distance to the traffic targets.

TECHNICAL FIELD

The present invention generally relates to graphical displays and, in particular, to displays used in operating a craft.

BACKGROUND

In operating a craft, such as an aircraft, submarine or lunar lander, the operator needs to quickly ascertain what traffic targets are approaching and determine how best to avoid the targets. Current technology provides the operator with much of the information needed to complete this task. For example, real-time sensors can indicate on a display where traffic targets are located. The ability of these sensors to accurately detect relevant data, such as target location, speed, direction, etc., is continuously being improved. However, current displays are limiting the ability of the operator to quickly understand the data being delivered from the sensors.

Unfortunately, most current displays do not adequately represent the relative location of traffic targets shown on the display. This limits the operator's ability to make a quick determination of which targets pose the greatest threats to the craft. In certain situations, such as in an aircraft, the ability to quickly ascertain such information is crucial to successful navigation of the craft. For example, where more than one target is present, the operator will need to know which target is closest to his own craft in order to determine in which direction the craft should be maneuvered first.

For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a display which will provide the operator with quick and easy access to depth and relational position data of traffic targets.

SUMMARY

The problem of providing a display which gives the operator of a craft quick and easy access to depth and relational position data of traffic targets is solved by the present invention of a perspective view conformal traffic targets display.

In one embodiment, a display system comprising a display screen for graphical display of data, one or more sensors for obtaining traffic data regarding traffic targets, and one or more processors for receiving traffic data from the one or more sensors and providing input to the display screen is provided. The display screen displays traffic targets as icons in a 3-dimensional graphical representation of real space. The display size of the icons is selected from a finite set of sizes which correspond to a finite set of distance ranges based on the distance to the traffic targets.

In another embodiment, a method for displaying conformal traffic in perspective view comprising checking real-time traffic sensor outputs, determining if detected traffic targets are within a field of view, selecting icon display size from a finite set of sizes which correspond to a finite set of distance ranges based on the distance to the traffic targets, and displaying the icons on a display screen is provided.

The present invention together with the above and other advantages may best be understood from the following detailed description of the embodiments of the invention illustrated in the drawings, wherein:

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the scope of the present invention. Furthermore, it will be understood by one of skill in the art that although the specific embodiments illustrated below are directed at aircraft for purposes of explanation, the method and apparatus may be used in various embodiments employing various types of crafts, such as submarines, space craft, lunar landers, and unmanned air vehicles (UAV), etc. The following detailed description is, therefore, not to be taken in a limiting sense.

Embodiments of the present invention may be described in terms of functional block diagrams and various processing steps. It should be appreciated that such functional blocks may be realized in many different forms of hardware, firmware, and or software components configured to perform the various functions. For example, embodiments of the present invention may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, look-up tables, and the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. Such general techniques are known to those skilled in the art and are not described in detail herein. Moreover, it should be understood that the exemplary process illustrated may include additional or fewer steps or may be performed in the context of a larger processing scheme. Furthermore, the various methods presented in the drawing figures or the specification are not to be construed as limiting the order in which the individual processing steps may be performed.

FIG. 1is an image of a graphical display according to one embodiment of the present invention. The graphical display includes traffic targets102-1. . .102-N. Traffic targets102-1. . .102-N have different sizes indicating the relative distance to each target. As depicted inFIG. 1, target102-2is larger than targets102-1and102-3, thus, indicating that target102-2is closer to the aircraft than targets102-1and102-3. In one embodiment, this conformal view (i.e. closer objects appear larger than objects further away as in the real world) is achieved by using a finite set of layers of conformal size. Each layer is associated with a specific range of distances and a specific icon size. Each traffic target located within a particular range is displayed using the same icon size. In one embodiment, there are 3 layers each associated with 1 of 3 distance ranges. A first range is 5 miles and greater, a second range is 2-5 miles, and a third range is 2 miles and less. Each target located in one of these ranges utilizes the same base icon size. These ranges are provided by way of example and not by way of limitation. In other embodiments, other appropriate range distances and number of ranges are chosen based on the intended application.

In another embodiment, the conformal view is achieved by changing the icon size for each target as a continuous function of distance to the target. The icon sizes are bounded by a maximum and a minimum icon size. The maximum and minimum icon sizes improves the clear visualization of all the targets by preventing icons for closer targets from occupying too much of the display and icons for targets located further away from being too small on the display. In such an embodiment, there is typically one range of distances used for determining when targets will be displayed on the screen.

In some embodiments, if a target is not within the field of view, it is caged against the side of the display. In other embodiments, if a target is not within the field of view, it is not displayed. In yet other embodiments, a filter is used to limit the display to the most pertinent traffic (e.g. targets that do not pose a threat are not be displayed). Additionally, in some embodiments, the color of the icon is changed to correspond to standard caution or warning alerts such as alerts in Traffic alert and Collision Avoidance Systems (TCAS).

The layered conformal size provides several advantages over other current approaches to display traffic targets. First, unlike current displays which typically render all targets the same size, the present display enables the operator to gain a quick general awareness of the relational position of targets. Second, it prevents target icons from getting too big or too small. For example, if the layers were not used, the target icons would continue to get larger as the distance to the target decreases and smaller as the distance increases. This approach would be more conformal. However, due the size and speed of typical targets (e.g. other aircraft), a target may be a potential threat at far distances where the icon is very small in a more conformal view or may maneuver very close where the icon will be so large it occupies too much of the display. Therefore, the layers prevent an icon from getting too small or too big so that the operator can be aware of the relational position of targets without sacrificing awareness of targets far away or losing display area to targets that are very close. Lastly, this layered conformal view reduces the load placed on the processor in determining the icon size allowing the processor to work more efficiently on other tasks.

FIG. 2is an image of a graphical display according to another embodiment of the present invention. The graphical display includes terrain208, flight symbology206, targets204-1and204-2, and indexing lines202-1and202-2. In some embodiments, terrain104includes mountains, ground, and rivers, etc. In other embodiments, terrain104includes geo-spatial boundaries, restricted airspace, etc. Although only two targets are displayed inFIG. 2, it will be understood by one of skill in the art that in other embodiments the display contains N number of targets and indexing lines. Indexing lines202-1and202-2run from targets204-1and204-2, respectively, to terrain208. The indexing lines in this embodiment further aid the operator in obtaining a quick perspective of the relational position of the targets. By connecting targets204-1and204-2to terrain208, the operator has better depth perception with regards to the targets' location. Additionally, in one embodiment, the indexing line alternates colors to indicate units of altitude. As depicted inFIG. 2, target204-1is 3 units above terrain208and target204-2is 4 units above terrain208. A unit may be any appropriate measure of altitude such as 1000 feet or 1000 meters, etc. Current displays do not typically include an indexing line for targets as in the present invention. Therefore, present invention provides an advantage over current displays by making it easier to gain depth perception regarding targets and easier to determine quickly the relative altitude of targets.

FIG. 3is an image of a graphical display according to another embodiment of the present invention. The display inFIG. 3also uses an indexing line as inFIG. 2. However, the indexing line inFIG. 3is used to indicate different data regarding targets304-1and304-2. Although only two targets are displayed inFIG. 3, it will be understood by one of skill in the art that in other embodiments the display contains N number of targets and indexing lines. InFIG. 3indexing lines302-1and302-2run from targets304-1and304-2, respectively, to a specified altitude306. In some embodiments, altitude306is the altitude of the operator's aircraft. In other embodiments, altitude306is a different appropriate altitude. As depicted inFIG. 3, it is easy for the operator to see how far a particular target is above or below the specified altitude306.

FIG. 4is an image of a graphical display according to another embodiment of the present invention. The display inFIG. 4also uses an indexing line as inFIGS. 2 and 3. However, the indexing line inFIG. 4is used to indicate different data regarding targets404-1and404-2. Although only two targets are displayed inFIG. 4, it will be understood by one of skill in the art that in other embodiments the display contains N number of targets and indexing lines. InFIG. 4, the indexing line is used to indicate the ascension or descension rate of targets404-1and404-2. As depicted by indexing line402inFIG. 4, target404-1is ascending at one unit per time division. The unit and time division can be any appropriate values for the intended use of the display. For example, in one embodiment the values are 10 miles per hour. Target404-2is neither ascending or descending as indicated by the lack of an indexing line.

FIG. 5is an image of a graphical display according to another embodiment of the present invention. The display inFIG. 5also uses an indexing line as inFIGS. 2-4. However, the indexing line inFIG. 5is used to indicate different data regarding targets504-1and504-2. Although only two targets are displayed inFIG. 5, it will be understood by one of skill in the art that in other embodiments the display contains N number of targets and indexing lines. InFIG. 5, the indexing line is used with an arrowhead to indicate the targets speed and direction of travel. As indicated by indexing line502-1, target504-1is traveling into the path of the operator's aircraft whereas, indexing line502-2indicates that target504-2is traveling away from the path of the operator's aircraft.

Each of the embodiments found inFIGS. 2-5provides the operator with useful information by using indexing lines. In other embodiments, the indexing line is used to show the projected location of a target in a given number of seconds. In yet other embodiments, the indexing line is used to show the projected location of a target when the target's projected path intersects with the craft's current projected path. The use of indexing lines in each of the embodiments enables the operator to gather that information quickly and easily. In some embodiments, the operator can switch between the different types of indexing lines as described above. In other embodiments, additional indexing lines are used to depict other important information for use by the operator. In yet other embodiments, multiple indexing lines are used for a single target to indicate different data regarding the target. In some embodiments, one or more indexing lines are used for each target displayed. In other embodiments, one or more indexing lines are only used for targets associated with a caution or warning alert. Additionally, in some embodiments, the color of the indexing lines will match the color of its associated icon.

FIG. 6is block diagram of a graphical display system according to one embodiment of the present invention. InFIG. 6, an exemplary graphical display system600includes processor604configured to provide information to display element or monitor606. One or more data sources are coupled to processor604. These data sources include, but are not limited to, navigation and control sensors608, navigational database610, terrain database612and traffic sensors602. In some embodiments, one or more of these data sources are omitted. The databases and sensors are typically located onboard the craft but it is not required that they be so located. For example, in some embodiments, the databases are located in a central flight tower or mission control center and the sensors are located on a surveillance craft or in a surveillance tower which relays traffic data to the craft. Additionally, each of these databases is instantiated as one or more databases. Data in these databases is stored on any type of suitable medium such as floppy disks, conventional hard disks, CD-ROM, flash ROM, nonvolatile ROM, RAM, or other suitable medium.

Processor604includes or interfaces with hardware components that support the graphics display system. By way of example and not by way of limitation, these hardware components include one or more microprocessors, memories, storage devices, interface cards, and other standard components known in the art. Additionally, processor604includes or functions with software programs, firmware or computer readable instructions for carrying out various methods, process tasks, calculations, control functions, and the generation of display signals and other data used in the operation of the display system. These instructions are typically stored on any appropriate medium used for storage of computer readable instructions such as floppy disks, conventional hard disks, CD-ROM, flash ROM, nonvolatile ROM, RAM, and other like medium.

Display element606includes any display element suitable for displaying the various symbols and information for the operation of embodiments of the present invention. There are many known monitors that are suitable for this task, such as various CRT and flat-panel display systems. Display element606is instantiated on a panel mounted display, a heads-up display (HUD) projection, flexible Organic LED (OLED) or any other existing or later developed display technology.

Processor604generates data for display on display element606based on positional and traffic data. In some embodiments, processor604is configured to receive and process navigation and positional data (e.g. position, speed, direction) regarding current aircraft location from navigation and control sensors608. In other embodiments, processor604is configured to receive navigation and positional data from navigational database610. Navigational database610is configured to store data concerning one or more flight paths. In one embodiment utilizing navigational database610, positional data is used to search for and display traffic for different locations along one or more flight paths helping an operator choose the safest path to follow. In yet other embodiments, processor604is configured to receive data from navigation and control sensors608and from navigational database610.

Based on the positional data, processor604obtains terrain data from terrain database612and traffic data from traffic sensors602. In one embodiment, terrain database contains data regarding the terrain and processor604sends a signal to display element606to render a simulated graphical representation of the terrain based on that data. In another embodiment, the terrain database contains actual images of the terrain and processor604sends a signal to display element606to display the actual image based on the positional data.

Traffic sensors602include any number of receivers, infrared lasers, millimeter wave cameras or other sensor elements for obtaining traffic data regarding traffic targets. In some embodiments, traffic data includes data about a target's location, speed, size, and trajectory. In other embodiments, traffic data also includes data about a target's aircraft type, flightplan, airline, class, and avionic equipage. Various known equipment is suitable for obtaining some or all of this data including Automatic Dependent Surveillance Broadcast (ADS-B) equipment and Traffic alert and Collision Avoidance Systems (TCAS).

Processor604analyzes the data received from traffic sensors602and determines if the traffic targets are located within the field of view. In some embodiments, traffic targets that are not within the field of view are not displayed. In other embodiments, targets that are not within the field of view are caged to the side of display element606.

Processor604also calculates the display icon size of targets. Based on the distance to each target, processor604assigns each target to one of a finite set of distance ranges. Each finite distance range is associated with one icon size. Each displayed target within a particular distance range will be displayed with the same size icon. This layered conformal view provides several advantages as discussed above with respect toFIG. 1.

In some embodiments, processor604analyzes the traffic data to determine the threat posed by each target. In some embodiments, processor604only sends a signal to display element606to display targets associated with a caution or warning. In other embodiments, processor604sends a signal to display element606to highlight and change the shape and color of displayed traffic targets to reflect the target threat. The threat is determined based on the target's size, proximity to the aircraft and trajectory. In some embodiments, the highlighting, shape and color change correspond to audio warnings and alerts such as TCAS alerts. Additionally, in some embodiments, processor604calculates indexing lines for targets based on data received from traffic sensors602and sends a signal to display element606to render indexing lines as discussed above with respect toFIGS. 2-5.

In one embodiment, the display view is an egocentric view (i.e. a view from current aircraft location). In another embodiment, the display view is an exocentric view (i.e. a view from a location other than current aircraft location). In yet another embodiment, a user can select between an egocentric and an exocentric view of the 3-dimensional graphical representation of real space.

FIG. 7is a flow chart showing a method of displaying traffic targets in a conformal perspective view according to one embodiment of the present invention. At704, traffic sensors are checked for traffic targets around a specified position or location. In one embodiment, these sensors pass data to one or more processors for immediate use. In another embodiment, these sensors pass data to a memory for recall and use by the one or more processors at a later time. If no targets are located, the process will continue at704until targets are located.

At706, it is determined if the traffic targets are located within the field of view of the display. In some embodiments, if located traffic targets are not within the field of view, those targets will not be displayed. In other embodiments, those targets not located within the field of view will be caged against the side of the display.

At708, the threat posed by each target is checked. In some embodiments, targets which are not associated with a caution or warning are not displayed. Additionally, in some embodiments, the icon color and object format is selected at710based on the target threat. In other embodiments, the icon selected for each target is representative of the target's type of craft.

At712, the icon display size for displayed targets is selected based on the distance to the target. In one embodiment, this selection is based on assigning each target to one of a finite set of distance ranges with an associated icon size as described above with respect toFIG. 1. In another embodiment, this selection is based on a continuous function of distance to the target as described above with respect toFIG. 1.

At714, the targets are displayed based on the size, object format, color and threat determinations made previously. At716, in some embodiments indexing lines are computed and displayed for the displayed targets as described above with respect toFIGS. 2-5. The process then repeats at704. In a preferred embodiment, the repeat rate is 20 times per second. In other embodiments, a slower repeat rate is used with predicative positioning, a technique known to one of skill in the art.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. For example, although the specific embodiments illustrated are directed at aircraft, the method and apparatus may be used in various embodiments employing various types of crafts, such as submarines, space craft, lunar landers, and UAVs, etc. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.