FIELD

The subject disclosure relates to unmanned aerial vehicles or other aircraft and more particularly to a method and system for unmanned aerial vehicle or other aircraft escape route planning.

BACKGROUND

Unmanned Aerial Vehicle (UAV) operations are expected to increase over the next years, including leisure and business operations, carried out manually steered in line of sight and automatic without human interference. With UAVs carrying payloads in urban areas in very low airspace, their ability to maneuver in case of engine failures or other failures is limited. The concept of ETOPS (Extended Operations) and downdrifts of commercial aircraft does not apply to UAVs, since reduced climb capabilities and obstacles need to be taken into consideration when finding a route to the nearest suitable landing site for the UAV.

SUMMARY

In accordance with an example, a method includes separating, by a processor, a flight plan of a vehicle into a number of portions with each portion including a particular length that is determined based on a complexity of an environment where the flight plan takes place. The complexity of the environment is based on at least one of a set of factors within the environment. The set of factors includes at least one of a terrain of the environment, one or more obstacles, one or more no-fly zones, or one or more no-landing zones within the environment. The method also includes determining, by the processor, an escape route for each portion of the flight plan of the vehicle. The escape route includes a route to a safe landing site in response to a failure of a system onboard the vehicle that requires the vehicle to land, drop a payload or both. The method additionally includes generating, by the processor, an escape route plan for the flight plan in response to all portions of the flight plan being assigned at least one escape route.

In accordance with another example, a system including a processor and a memory associated with the processor. The memory incudes computer-readable program instructions that, when executed by the processor causes the processor to perform a set of functions including separating a flight plan of a vehicle into a number of portions with each portion including a particular length that has been determined based on a complexity of an environment where the flight plan takes place. The complexity of the environment is based on at least one of a set of factors within the environment. The set of factors include at least one of a terrain of the environment, one or more obstacles, one or more no-fly zones, or one or more no-landing zones within the environment. The set of functions also include determining an escape route for each portion of the flight plan of the vehicle. The escape route includes a route to a safe landing site in response a failure of a system onboard the vehicle that requires the vehicle to land, drop a payload or both. The set of functions additionally include generating an escape route plan for the flight plan in response to all portions of the flight plan being assigned at least one escape route.

In accordance with an example and any of the preceding examples, wherein the method and system also include computing one or more escape route volumes around each landing site of one or more landing sites, wherein determining an escape route for each portion of the flight plan includes using the one or more escape route volumes.

In accordance with an example and any of the preceding examples, wherein computing the one or more escape route volumes includes using one or more of a plurality of inputs. The plurality of inputs include at least one of type data indicative of a type of the vehicle, normal performance data indicative of a normal performance model of the vehicle, degraded performance data indicative of a degraded performance model of the vehicle, first location data indicative of a location of a landing site, second location data indicative of a location of a no-fly-zone, third location data indicative of a location of a payload drop site to extend remaining battery power for operation of the vehicle, obstacle data, a micro weather forecast data, historical data associated with a history of micro weather, battery condition information, a deviation between planned and actual conditions during flight, or an uncertainty of any of the inputs.

In accordance with an example and any of the preceding examples, wherein the determining the escape route for each portion of the flight plan includes determining at least one four-dimensional (4D) escape route for each portion of the flight plan.

In accordance with an example and any of the preceding examples, wherein the at least one 4D escape route includes a volume defined by the portion of the flight plan and at least one closest landing site to the portion of the flight plan, changes to the volume as the vehicle moves along the portion of the flight plan, uncertainty in the plurality of inputs and deviation from the flight plan.

In accordance with an example and any of the preceding examples, wherein the method and system further include determining the flight plan of the vehicle using a set of navigation data.

In accordance with an example and any of the preceding examples, wherein the set of navigation data is indicative of at least one of a defined airway, a location of a suitable regular landing site, a location of a suitable emergency landing site, a location of a no-fly-zone, one or more no-landing zones, one or more payload drop sites, or a database of obstacles.

In accordance with an example and any of the preceding examples, wherein the method and system further comprising rerouting a particular portion of the flight plan in response to the particular portion not having an assigned escape route.

In accordance with an example and any of the preceding examples, wherein rerouting the particular portion of the flight plan includes rerouting the particular portion of the flight plan closer to a suitable landing site.

In accordance with an example and any of the preceding examples, wherein the method and system further include receiving current or updated data; and modifying the escape route plan based on the current or updated data.

In accordance with an example and any of the preceding examples, wherein the current or updated data is received by the vehicle and the escape route plan is modified by the vehicle.

In accordance with an example and any of the preceding examples, wherein the current or updated data is received by at least one of a ground station or another vehicle and the escape route plan is modified by at least one of the ground station or the other vehicle. The method and system further include transmitting a modified escape route plan to the vehicle.

In accordance with an example and any of the preceding examples, wherein the current or updated data comprises at least one of a change in a location of a landing site, a change in a location of a no-fly-zone, a change in a location of a payload drop site, a change in a database including obstacles, a change in a micro weather forecast, or a deviation between planned and actual conditions during flight.

In accordance with an example and any of the preceding examples, wherein the method and system further include executing the escape route plan in response to detecting a failure of a system onboard the vehicle that requires the vehicle to land, drop a payload or both.

In accordance with an example and any of the preceding examples, wherein executing the escape route plan includes landing the vehicle at a closest landing site based on the escape route plan.

In accordance with an example and any of the preceding examples, wherein executing the escape route plan includes: dropping a payload at a payload drop site based on a condition of the vehicle and the escape route plan; and landing the vehicle at a closest landing site based on the escape route plan.

In accordance with an example and any of the preceding examples, wherein the method and system further include: detecting a change in health of the vehicle; and modifying the escape route plan in response to detecting the change in the health of the vehicle, wherein modifying the escape route plan comprises modifying at least one of a particular escape route or a particular portion of the flight plan and an assigned escape route.

In accordance with an example and any of the preceding examples, wherein modifying the escape route plan is performed by the vehicle.

In accordance with an example and any of the preceding examples, wherein modifying the escape route plan is performed by a ground station or another vehicle.

The features, functions, and advantages that have been discussed can be achieved independently in various examples or may be combined in yet other examples further details of which can be seen with reference to the following description and drawings.

