Abstract:
Integrated surveillance systems and methods for processing multiple sensor inputs and determining a best route for avoiding multiple hazards. An example method performed on a first aircraft includes generating a plurality of routes for avoiding a previously determined alert from a first advisory system. Then, probability of success information is generated at other advisory systems for each of the plurality of routes. The best route of the plurality of routes is determined based on the generated probabilities and output to the flight crew or other aircraft. The probability of success information includes a previously defined uncertainty value. The uncertainty value corresponds to quality of data provided to or provided by the respective advisory system.

Description:
PRIORITY CLAIM 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/050,190 filed May 2, 2008, the contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Maintaining or increasing current levels of aviation safety with tripled capacity and traffic flow is a daunting task. Supporting pilots&#39; awareness and ability to respond accurately and quickly to potential hazards is a critical element to acceptable future safety levels. Yet pilots&#39; task and information loading in the emerging US Next Generation (NextGen) and Single European Sky Air Traffic Management Research (SESAR) environments could significantly increase, leading to increased potential for errors and increased safety risks rather than the hoped for decreases. 
         [0003]    Existing aircraft advisory systems issue advisories independently of advisories of other aircraft advisory systems. For example a Traffic Collision and Avoidance System (TCAS) system may issue an advisory to “descend, descend.” However, if the aircraft is flying close to terrain, the Enhanced Ground Proximity Warning System (EGPWS) system issues an advisory “terrain, terrain”, “pull up, pull up” Just such incidents were reported to the NASA Aviation Safety and Reporting System (ASRS). In this time-critical, stressful situation, the pilots had to decide on their own which alert would take precedence and the appropriate action to take. Indeed this decision was made even more difficult by the blaring audio alerts. Each system was designed with its own goals and objectives. Since the systems are separate and independent they do not have a common framework to share intent. The pilots were left on their own to de-conflict the alerts. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides integrated surveillance systems and methods for processing multiple sensor inputs and determining a best route for avoiding multiple hazards. 
         [0005]    An example method performed on a first aircraft includes generating a plurality of routes for avoiding a previously determined alert from a first advisory system. Then, probability of success information is generated at other advisory systems for each of the plurality of routes. The best route of the plurality of routes is determined based on the generated probabilities and output to the flight crew or other aircraft. 
         [0006]    In one aspect of the invention, the generation of routes are based on information received from one of a Flight Management System (FMS) or a Flight Control System (FC). 
         [0007]    In another aspect of the invention, the probability of success information includes a previously defined uncertainty value. The uncertainty value corresponds to quality of data provided to or provided by the respective advisory system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings: 
           [0009]      FIG. 1  is a block diagram of an example system formed in accordance with an embodiment of the present invention; and 
           [0010]      FIGS. 2 and 3  are flow diagrams of example processes performed by the system shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    The present invention is an integrated surveillance system that processes multiple sensor inputs, e.g. Traffic Alert Collision Avoidance System (TCAS), Enhanced Ground Proximity Warning System (EGPWS), Weather Radar, Automatic Dependent Surveillance-Broadcast (ADS-B) In System and inputs from other aircraft systems, i.e., Flight Management System (FMS)/Flight Control System (FC). The reason for the FMS/FC input is to determine the aircraft state, speed, attitude, flap settings, etc, which could impact the responsiveness of the aircraft to execute a certain maneuver, e.g. it might be hard to perform a speed up advisory if the flaps are extended. One of the key features of this new cognitive function is the analysis of a probability of outcome tree. If it is 100% certain that you will hit the ground if you descend and 100% certain that you will collide with traffic if you climb, but 100% certain that you will avoid terrain and only 50% certain that you will collide with the traffic if you pull up and right and speed up, the system would recommend the 50% solution. The system checks the probability of safe outcome for all possible combinations of maneuvers and recommends the combination with the highest probability of a safe outcome. 
         [0012]    It is also possible that one or more of the advisories will have deterministic uncertainty. For example, the position of another aircraft reported by the ADS-B In system may have uncertainties based on the navigation signals used by the reporting aircraft and the latency of the data. Therefore, in addition to knowing the mean probability that a particular advisory action, e.g. heading change, will result in a safe outcome, there will be an uncertainty or variance in the probability as well. The TCAS system has a known bearing uncertainty relative to the heading of the subject aircraft. Therefore, the probability of having a safe outcome from a hazardous situation based on a particular advisory, e.g. new heading, will have a corresponding uncertainty or variance. The cognitive function performed by the system would also take the uncertainty or variability into account in addition to the mean probability. An example would be as follows. If the TCAS system advised that another aircraft was approaching from a relative bearing 15 degrees left of heading and the TCAS bearing uncertainty was 5 degrees, the advisory would include a no fly zone from 10 degrees to 20 degrees to the left of heading. 
         [0013]    In one embodiment, uncertainty or variance is a constant for data from a particular system. In another embodiment uncertainty or variance is formed from a combination of factors. For example, if the GPS receiver is not working or receiving adequate signals, the position of the aircraft may be know with less certainty. This coupled with uncertainty or variability in the TCAS bearing accuracy would result in a different variance than due to the TCAS uncertainty alone if the GPS receiver were working perfectly. 
         [0014]    In another embodiment, the present invention exchanges advisories and aircraft state information between aircraft, e.g. if one aircraft cannot dive because of terrain perhaps the two aircraft can execute a coordinated maneuver that has a higher probability of success than two individual, self optimized maneuver advisories. 
         [0015]    In another embodiment, the present invention utilizes information about the aircraft involved in the hazardous situation from other external systems, such as ground based or satellite based surveillance systems. These other systems may have a different perspective on the hazardous situation than would result in a safer outcome when considered with the on-board sources of data. The ground or satellite based systems would provide aircraft traffic or weather hazard information to the aircraft to integrate into the integrated surveillance system calculations. 
         [0016]    The benefit of this invention is that it analyzes the impact of an advisory from one system (internal and/or external) that would result from that advisory from other hazard systems&#39; perspectives. 
         [0017]    In one embodiment, a cognitive advisory function is added to an integrated surveillance systems (ISS) or added as an integrating function in aircraft with federated surveillance systems. This function allows the ISS to monitor surveillance systems for hazardous situations and calculate the probability (mean and variance) of successful evasion of hazards and the margins of safety based on inputs from various sensor systems such as TCAS, EGPWS, weather radar, and enhanced vision systems. Additionally, the probability of successful outcome can be improved by considering aircraft state and dynamics information from the FMS and/or FCS. These inputs will enable the ISS to predict the probability of the aircraft to execute candidate evasive maneuvers, thereby adding to the fidelity of the resultant advisory to the pilot. Information from other aircraft involved in the hazardous situation and from other sources such as ground based and satellite based surveillance systems can be added to the cognitive advisory function. 
         [0018]    Note that this cognitive function can be implemented by the use of other mathematical or geometrical methods other than the mean and variance of the probability of a successful outcome. Similar benefits are realized by exchanging three dimensional “keep out” zones, which would describe the hazardous volumes identified by a particular sensor. By fusing all of these hazardous volumes and factoring in the aircraft state and performance information, the cognitive function determines the best path through the hazards. The fundamental innovation of this invention is the cognitive integration of dissimilar surveillance and other aircraft systems (whether on the subject aircraft, other aircraft, ground based and/or satellite based systems). 
         [0019]    In one embodiment, as shown in  FIG. 1 , a system  20  on an aircraft includes an Integrated Aircraft Advisory System (IAAS)  30  that receives output from multiple sensor inputs (a TCAS  34 , an EGPWS  32 , a Weather Radar  36 , an FMS  38 , an FC  42 , an Enhanced Vision System (EVS)  40 , and/or external sources via a data link communications  44  then calculates a maneuver for the aircraft and outputs the calculated maneuver to the flight crew via an input/output device(s)  46 . Example input/output devices  46  include speakers, headsets, displays, warning lights, etc. The IAAS  30  performs an analysis of a probability of an outcome for two or more evasive maneuvers. The data links communications  44  could be one of many different types of data links, such as data links typically used for surveillance purposes (ADS-B IN, TIS-B (Traffic Information System-IN)) or data links traditionally used for data communications (ACARS (Aircraft Communications Addressing and Reporting System) and VDLM2 (VHF Data Link Mode 2)). 
         [0020]    In another embodiment, the IAAS  30  exchanges advisories and aircraft state information with other aircraft via the data link communications  44 . If a first aircraft cannot descend because of terrain, the first aircraft and a proximate second aircraft can execute a coordinated maneuver that has a higher probability of success than two individual, self optimized maneuver advisories. 
       Develop an Integrated Pilot Alerting and Notification Concept 
       [0021]    The present invention is an Integrated Alerting and Notification (IAN) adaptive information management system that will be able to account for user&#39;s current cognitive capacity to receive, understand, and integrate information, and be able to determine the user&#39;s level of interpretability as new alerting and notification information becomes available. The IAAS  30  intelligently manages the information flow to the pilot in order to maximize information throughput and situation awareness while minimizing the cognitive overhead imposed by information management. 
         [0022]    The IAAS  30  performs the integration of many different types of sensor and detection systems into a coherent and coordinated set of displays and controls that provide unprecedented assistance to the pilot. The areas of technology required for the creation of IAN are:
       Hazard Detection—sensor based hazard warnings that rely on radar, lidar, vision systems such as Forward Looking Infrared Radar (FLIR), temperature sensors, and other aircraft based sensing systems.   Hazard Determination—processing based warnings that are derived from database information, such as the EGPWS where GPS and radar altimeter information are correlated to a terrain database to warn pilots of upcoming terrain features; the provision of offboard sensor information such as ADS-B information from other aircraft in the area; or provision of weather or other data obtained from ground based sensors.   Communications—the transmission of information to the aircraft from other aircraft or the ground to provide ADS-B, terrain update, weather information updates, or other data that would assist in navigation, hazard avoidance, or flight efficiency.   Sensors and Database Fusion—where sensors may be combined, or sensors and databases may be combined, to yield not only a single view of the operational space, but will permit the derivation of additional data not available in the individual components.   Hazard Assessment and Deconfliction—where the information from all sensors and sources is combined, prioritized, and presented in order of most important and/or most cogent.   Integrated Alerts, Notifications, and Information Displays—the presentation of relevant external awareness information relevant to hazard avoidance and strategic planning, presented in a manner that blends easily with other cockpit information.   Methods, Modeling, and Metrics—the ability to objectively assess the performance of similar but varied concepts that address the problem space.       
 
         [0030]      FIGS. 2 and 3  illustrate an example process  80  performed by the system  20  shown in  FIG. 1 . First, at a block  84 , the IAAS  30  receives an advisory or an alert from one of the advisory systems ( 32 ,  34 ,  36 , or  40 ). Next, at a block  85 , either one of the advisory systems or the IAAS  30  calculates potential maneuvers to avoid the determined threat included within the advisory/alert based on current aircraft state and performance information received from the FMS  38  and/or the FC  42 . At a block  86 , the IAAS queries the other advisory systems that did not produce the received advisory and/or alert. The query requests that those other advisory systems analyze the calculated potential maneuvers to determine a probability of success using any predefined uncertainty (variance) information. Next, at a block  88 , the results of the query are sent to the IAAS  30  which compares the results. At a block  90 , the IAAS  30  determines the best maneuver based on the performed comparison. At a block  92 , the IAAS  30  outputs the determined best result to the input/output devices  46  and/or sends it to other vehicles or aircraft via the data link communications  44  (block  94 ). 
         [0031]    In one embodiment, the query request is sent to systems external to the aircraft, such as other aircraft or ground or satellite-based systems. The other aircraft determines maneuvers in response to potential maneuvers received and then analyzes the determined maneuvers in a similar manner as described in blocks  86 - 90 . The determined best (or two or more best) maneuvers are returned to the aircraft having begun the original query. This interactive analysis may occur a few times until all the aircraft have agreed upon the best maneuvers for all. 
         [0032]      FIG. 3  illustrates a process  98  that another aircraft would perform upon receiving a best route determination received from a proximate vehicle. At a block  100 , the other aircraft receives the determined best route information from proximate vehicle. At a block  102 , a system aboard the other vehicle generates two or more route options for avoiding the other aircraft based on the received route information. At a block  106 , an IAAS  30  of the other aircraft queries its resident advisory systems to perform an analysis of the generated two or more route options. At a block  108 , the IAAS  30  of the other aircraft compares the results of the query. At a block  110 , the IAAS determines the best of the generated two or more routes based on the performed comparison and at a block  114  outputs the determined best route to the input/output device  46  of the other aircraft. 
         [0033]    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.