Unmanned aircraft system for inspecting railroad assets

Abstract

To provide an unmanned aircraft system for inspecting railroad assets.SOLUTION: An aerial system control network and an unmanned aircraft (UAV) system and method (2600) are provided for inspecting railroad assets using a UAV. The aerial system control network comprises multiple towers and a ground control system connected to multiple communication towers. The ground control system includes: transmitting a flight plan including railroad lines and a flight path through the multiple communication towers; receiving data through the multiple communication towers while the UAV is monitoring railroad lines; detecting obstacles along the flight path based on the received data; and adjusting the flight plan based on the obstacles.SELECTED DRAWING: Figure 26

Description

Technical Field

[0001] The present disclosure generally relates to railway asset management, and more particularly to an unmanned aerial vehicle system for inspecting railway assets.

Background Art

[0002] The safety and efficiency of railway operations rely heavily on the continuous analysis of trains, railway rights-of-way, tracks, and other assets / facilities. There are various factors that can affect the track condition and impact the movement of trains, including criminal activities and abnormal weather events that can cause track flooding, subgrade erosion, or overheating (tracks can bend or become distorted due to high heat). Earthquakes, landslides, and abandoned vehicles and other objects on crossings can obstruct the tracks.

[0003] Vigilance is always the best defense against these hazards. As a result, in accordance with Federal Railroad Administration (FRA) regulations and company policies, employees responsible for track / right-of-way and bridge maintenance regularly inspect the tracks and underlying infrastructure (bridges, tunnels, support structures, signals, etc.). Currently, this work is mainly carried out by employees using automobiles, on foot, dedicated rail equipment, or rail-mounted hi-rail (rail / road) vehicles. This work is often labor-intensive and can be strenuous. Railway companies do everything they can to make human inspections as safe and accurate as possible. However, there are always irreducible risk elements associated with employees having to go outside to examine the tracks and rail structures. Employees may need to straddle or ride on the track structure. The track structure is slippery, uneven, and / or can be exposed to all weather conditions. Some structures, such as bridges, are located high above the ground. Trains moving through inspection zones can increase the risk, especially in areas with high traffic volume.

Summary of the Invention

Means for Solving the Problems

[0004] Embodiments of the present disclosure provide an aerial system control network, an unmanned aerial vehicle (UAV) system, and a method for inspecting railway assets using an unmanned aerial vehicle.

[0005] In an exemplary embodiment, the aerial system control network provides for inspecting railway assets using an unmanned aerial vehicle. The aerial system control network includes a plurality of towers and a ground control system connected to the plurality of towers. The ground control system transmits a flight plan including a railway line and a flight path via a plurality of communication towers, receives data while the UAV is monitoring the railway line via the plurality of communication towers, detects obstacles along the flight path based on the received data, and adjusts the flight plan based on the detected obstacles.

[0006] In another exemplary embodiment, an unmanned aerial vehicle (UAV) system provides for inspecting railway assets using an unmanned aerial vehicle. The unmanned aerial vehicle (UAV) system includes a UAV and an aerial system control network. The aerial system control network includes a plurality of towers and a ground control system connected to the plurality of towers. The ground control system transmits a flight plan including a railway line and a flight path via a plurality of communication towers, receives data while the UAV is monitoring the railway line via the plurality of communication towers, detects obstacles along the flight path based on the received data, and adjusts the flight plan based on the detected obstacles.

[0007] In another exemplary embodiment, a method provides for inspecting railway assets using an unmanned aerial vehicle. The method includes transmitting a flight plan including a railway line and a flight path via a plurality of communication towers, receiving data while the UAV is monitoring the railway line via the plurality of communication towers, detecting obstacles along the flight path based on the received data, and adjusting the flight plan based on the detected obstacles.

[0008] Other technical features may be readily apparent to those skilled in the art from the following figures, description, and claims.

[0009] To obtain a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts.

Brief Description of the Drawings

[0010]

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DETAILED DESCRIPTION OF THE INVENTION

[0011] The figures 1-26 discussed below and the various embodiments used to explain the principles of the present disclosure of this patent document are merely examples and should in no way be construed as limiting the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented with any type of device or system appropriately arranged.

[0012] Preferred embodiments of the principles of the present invention are based on an unmanned aerial vehicle (airplane) capable of vertical takeoff and landing. In particular, the aircraft includes an autopilot system that interfaces with a system command and control infrastructure. The aircraft also supports various on-board sensors that process navigation information generated from a geographic information system and provide location information. The aircraft and the entire railway right-of-way system are also characterized by having devices capable of transmitting and receiving information with an on-board navigation beacon (ADSB) and / or a Mode C transponder or their equivalents.

[0013] Embodiments of the aircraft have sufficient on-board power generation capacity to provide reliable power to all of the various aircraft systems, such as sensors, communication, and control subsystems. In addition, the aircraft preferably has a sufficient liquid fuel capacity to support a flight time of more than 8 hours. The aircraft also has a plurality of sensors for collecting information and a payload capacity necessary to support the communication and control subsystems required to pass that information in real time to a flight operations center. The aircraft also preferably includes an on-board information storage medium for local storage of the collected information. In addition, the system includes both on-board subsystems and external subsystems to facilitate emergency maneuvering and landing of the aircraft in the flight corridor.

[0014] Generally, the on-board sensors take high-resolution, accurate location photos with a resolution of at least 1 / 4 foot from the operating altitude more than twice per second. Preferably, the sensor system also has an independent communication ability to communicate with other on-board subsystems, including built-in local computing capabilities, its own navigation system, and autopilot. The sensors can include photo sensors, video cameras, thermal detection cameras, and / or multispectral sensors. Specifically, the sensor system includes a real-time day / night video camera for the pilot's situation awareness that includes at least some limited real-time protection capabilities.

[0015] The system also includes software focused on rail detection and analysis of the condition of railway land. Thereby, inspections of linear assets such as tracks, bridges, and the like are advantageously supported. In particular, the system software (both on-board and remote) includes machine vision software trained to understand and recognize critical situations within an area having at least two linear boundary lines. The system software can also demonstrate normal functional states on the linear area.

[0016] More specifically, the onboard software is launched on the aircraft in a straight line connecting the sensor and the ground-based communication system. The onboard software processes the data collected by the sensor. The data is then loaded into the ground-based communication system. In response, the ground-based communication system outputs quantitative and qualitative data regarding what the sensor has captured. The software system processes the large amount of data, creates another set of geographically located data, and then creates a third data set. The system software creates several reports associated with the target data and creates a geographical location file that enables the user to easily map the location of the selected state of the target. Preferably, the large amount of data remains unprocessed. The receiver receives only the usable data that is truly necessary. The large amount of data is stored for future data mining and use.

[0017] In addition, the system software also includes field information software. The field information software can be used separately from this system or even on multiple aircraft. The field information software embodies algorithms for mapping functionality, determines the order in which the software should execute operations, thereby advantageously eliminating human errors. Specifically, the field information software receives media generated by the sensor system, transfers that data to a laptop or other processing system, and then starts the local software. The local software automatically performs data encoding, labeling, and transfer to drives and files, and appropriately sends those data to anyone who needs them (e.g., different departments within an organization). The field information software can be used for any data collected related to the field location. The field information software preferably is based on a network connection system including a server or a set of hardware devices. In some embodiments, the field information software is activated after the flight by the aircraft (i.e., performs post-flight data processing). The data can be distributed among network connection resources. The network connection resources perform further analysis and ensure that proper encoding and storage of the data are carried out. This helps maintain the management of the distribution process and minimizes data errors.

[0018] The railroad right-of-way, galleries, and towers are important factors in the aerial railroad inspection system. This system accesses the 900 MHz channels used for the Automatic Train Control System (ATCS) implemented through AAR. However, the actual spectrum used is not a strict requirement for the practice of this principle, and other secure and approved spectrums can be used. The hardware and software of this system are optimized to use low-bandwidth AAR channels for higher functionality. In the case of a system using preferred AAR channels, users usually require a license. Redundant Ethernet (registered trademark) controls communication with aircraft, including appropriate channels. These functions can be implemented by railroad telecommunications assets.

[0019] The aircraft is preferably an aircraft that performs vertical takeoff and landing and operates (including landing) throughout along the railroad asset network. When the aircraft takes off, the pilot issues an autopilot command to start flying. The flight starts following the route to the actual railroad right-of-way programmed by the Geographic Information System, the aircraft flies, and then it follows that railroad right-of-way. In other words, when the pilot activates the autopilot, the system software takes over the operation and flies the aircraft as close as possible to the track when it comes over the track. Also, the software system enables the sensor to automatically take pictures of the track twice per second. At the same time, the sensor and software system control the pitch, yaw, and roll of the aircraft and the sensor. As a result, one or more appropriate sensors can be placed over the track while keeping the track in focus to ensure the required resolution and overlapping images. If the analysis software determines that there is not enough overlap after the flight or if part of the track is missing due to railroad right-of-way occupancy, it quickly flies that route again and the sensor takes additional pictures.

[0020] While the autopilot is activated and the sensor is taking pictures, the aircraft control system utilizes space-based GPS (or ground-based GPS error correction if available) to position the aircraft over the railway right-of-way while maintaining the operating altitude and compliance with the linear flight path. Both ensure compliance with the sensor resolution and the regulatory requirements regarding the height and width of the flight path.

[0021] Also in this case, preferably, the aircraft and the sensor have independent navigation systems. Advantageously, when both the aircraft and the sensor have independent navigation systems, the computing power is reserved for the critical items imposed on each component. For example, the sensor system may include sensor stabilization software and hardware. Also, the sensor can disable the image collection function if it is not over the private land of the railway operator.

[0022] Preferably, the aircraft broadcasts its location, speed, altitude, and heading via the existing FAA surveillance network (SBS) and also broadcasts to other aircraft equipped to receive these signals. In addition, the railway infrastructure can support the FAA SBS system using auxiliary ADSB / transponder receivers, radars, and other elements placed along the railway right-of-way. While the aircraft is in flight, its operating status, location, and overall soundness are transmitted to the pilot via the command and control link. During all flight phases, the aircraft has access to multiple command and control transceiver locations, and a level of command and control redundancy is guaranteed.

[0023] If the aircraft loses connection to the command and control system, after a time period determined by the operator and / or FAA regulations has elapsed, the aircraft will initiate its "link loss profile" and return to the departure point via a pre-determined route, or automatically descend and land along the railroad right-of-way in the event of a loss of communication and power. The pilot will be aware of the link loss situation and, based on the last transmission from the aircraft, will notify users and dispatchers on the railroad right-of-way about the aircraft's notable landing. Also, secondary communication and navigation systems of the sensors can assist in positioning the aircraft.

[0024] If there is another critical system failure during flight, the aircraft will automatically initiate one of several pre-determined end-of-flight procedures or return to its departure location or another safe location as programmed. During the flight, the pilot has the option to utilize secondary sensors for real-time imagery of the railroad right-of-way. Also, this secondary sensor can be used for some situation analysis but is mainly used for pilot awareness. During the flight, if a critical situation is identified, the aircraft's sensors can utilize a secondary communication channel that is not the primary connection to send an immediate notification to the pilot.

[0025] Upon completion of the assigned mission, the pilot will engage in the landing procedure. The aircraft will utilize all of the aforementioned systems to reach the landing site and engage in the landing procedure for vertical landing. The landing procedure includes activating an air-to-ground laser that provides precise landing information to the aircraft. During the final stage of the pre-landing flight, the pilot will use the aircraft command and control system to ensure a safe landing. The aircraft is equipped with multiple support systems to ensure a safe landing. If anything that impedes a safe landing exists on the ground or in the landing area, the landing abort procedure will be initiated and an alternative landing site will be used. After a safe landing, the pilot will remove the sensor data storage drive and insert it into the server. The server system will then initiate an automated process of analysis and data distribution, resulting in the distribution of customized reports and useful datasets.

[0026] FIG. 1 shows an exemplary line network 100 according to various embodiments of the present disclosure. Although a line network is shown in FIG. 1, the principles of the present disclosure are equally applicable to other types of networks. The embodiment of the line network 100 shown in FIG. 1 is merely exemplary. Other embodiments of the line network can be used without departing from the scope of the present disclosure.

[0027] The freight transportation line network shown in FIG. 1 is approximately 32,500 miles of railroad lines in the western United States where most of the area is rural. To protect this important transportation infrastructure and nearby communities, various on-track vehicles and equipment are currently used to perform regular inspections. To enhance those inspections while improving the labor safety of railroad employees, aerial monitoring of the railroad infrastructure can be performed using an unmanned aircraft system (UAS). These operations can be beyond visual line of sight (BVLOS) in both day and night and in visual meteorological conditions.

[0028] Tracks (including the freight transportation line network), the areas around them ("right-of-ways"), and the assets on the right-of-ways are accurately monitored using GPS (Global Positioning System) and other technologies such as LIDAR (Light Detection and Ranging). A corporate-level Geographic Information System (GIS) includes this data. This information is used for the planning and execution of flights directly above the right-of-ways.

[0029] The unmanned aircraft (UA) is capable of vertical takeoff and landing (VTOL) and has a flight endurance of 10 hours at a cruise speed of approximately 40 kts with a sprint speed exceeding 60 kts. The navigation method uses a GPS waypoint-based flight plan. The flight route is at an altitude of 400 ft or less above the ground directly above the railway line. The cruise altitude is typically 380 ft AGL. The autopilot can maintain this altitude within + / - 10 feet in calm wind conditions and can correct when the aircraft is pushed up or down by wind or environmental factors. The navigation performance of the system is such that the UA stays within a lateral corridor of approximately + / - 100 ft from the centerline of the main railway line. This lateral corridor corresponds to the boundary of the property. Most avoidance maneuvers or loitering flights can be completed within + / - 1,500 ft from the main track centerline if necessary to maintain safety. The sensors installed on the UA are designed to have a narrow field of view such that the data and images collected are only of the track area.

[0030] The railway network is organized into sections and subsections. Each subsection includes a track length of 50 - 300 miles in length. The subsections are interconnected. Near each end of the railway subsections, there are yard facilities occupying extensive land (acres). Staff and equipment for supporting UAS operations can be placed in these yard facilities. The operator can operate the UAS by launching from the yard, flying along the subsection, and landing at the next yard (where inspections, maintenance, refueling, and relaunch of the UA can be performed) over most of the network. The operator can perform two flight missions in up to 100 subsections per day.

[0031] To monitor and control the UAS, the operator can leverage its experience in the development and deployment of PTC (Positive Train Control). The operator can use its existing telecommunications infrastructure, including private secure tower facilities and a terrestrial backhaul network, to implement voice communications over VHF aviation radio or provide flight crews with weather information from a series of weather observation stations located along the track for command and control (C2) of the UAS fleet.

[0032] The telecommunications network is designed to be robust and redundant. The telecommunications network reaches up to the network operations center (NOC) of its headquarters. From the NOC, any train located in any subdivision of the network can be dispatched. From this central location, switches and signals along its entire route are controlled, and crew coordination over voice radio is carried out. Similarly, each UAS can be controlled from the ground control station (GCS) of the flight control center of its region by one pilot-in-command (PIC) and one copilot from the flight control center or central location of its region. During flight time, it is possible to control the aircraft from multiple locations. For example, the flight control center of its region can initiate the flight and then transfer the aircraft to another flight control center without landing. Command and control can be accomplished using variations of CNPC (command non-payload control) or C2 (command and control) radio in a dedicated spectrum. Voice communications are accomplished via remotely controlled aviation VHF transceivers mounted on towers along the railroad right-of-way. Also, UAS operations also utilize the existing network of weather observation stations located alongside the local tracks.

[0033] The telecommunications infrastructure is also used to support an air traffic situational awareness system. This system can display the positions of both cooperative and non-cooperative air traffic to the pilot of the UAS. The UA itself is a cooperative aircraft. The UA can be equipped with a Mode S transponder with ADS-B output.

[0034] The UAS operation flight control center is built in the locomotive yard facility and can perform inspection tasks more efficiently and cost-effectively. The flight crew plans the safety inspection tasks for the area as needed. From the dedicated UAS maintenance and data processing facilities in the operation flight control center, the ground crew can prepare the UAV for its mission and supervise the launch and recovery operations. By flying the UAV from its GCS, the flight crew can utilize the UAV's flight distance and duration to fly over one or more sub-areas as per the flight plan. Some data is streamed live during the flight operation. The remaining data is returned to the flight control center for post-processing. All relevant data is transferred to cloud data storage for timely dissemination to appropriate end-users such as track inspectors, engineers, and maintenance planners.

[0035] Figure 2 shows an exemplary unmanned aircraft system (UAS) operation flight control center 200 according to various embodiments of the present disclosure. The embodiment of the UAS operation flight control center 200 shown in Figure 2 is merely exemplary. Other embodiments of the UAS operation flight control center can be used without departing from the scope of the present disclosure.

[0036] Figure 2 illustrates the concept of the flight control center. In the railway locomotive yard, five sub-areas are connected. Important parts of the other four sub-areas are within 175 miles. Across this area, many locations where gunite water occurs, track sections where thermal buckling is likely to occur, areas where signal feedback for monitoring of dangerous assets is not available, and several dangerous bridges are seen. These connected sub-areas can benefit from aerial safety inspections and timely detection of problems provided by this technology.

[0037] A typical railroad subdivision 205 begins at a railroad yard on the outskirts of a populated area, extends into rural areas, and terminates at another yard near a populated area. Along the way, the track 210 is close to major and peripheral roads, passes near or through small towns or villages, and passes near an airport. However, since the UA can fly directly over the railroad operator's property, except for a very short time (about a few seconds) when crossing a road, the UAS may not fly directly over a third party. The UAS may feature some safety protocols designed to keep the UA over or on the railroad operator's private property in case of an emergency.

[0038] Since the yard or subdivision section may be located on the surface within the airspace boundary, the UAS is regulated when flying in Class G, Class E, Class D, Class C, and Class B airspace below 400 ft AGL. The UAS is designed not to require takeoff and landing from an airport with a control tower. The procedures described in paragraphs

[0102] to

[0128] are used to operate in controlled airspace, near airports, and known flight activity locations. In conjunction with the technology, many operational and procedural safety mitigations can be implemented. They are all intended to maintain situational awareness of manned air traffic and coordination with manned air traffic. Note that the UA is equipped with a transponder and the flight crew may have two-way voice communication. The position of the UA relative to the airport and detected air traffic is monitored on the GCS using a moving map display with a VFR sectional aeronautical chart overlay. In this way, BVLOS UAS operations are similar to manned aircraft operations, especially in Class B, C, and D airspace. Regarding Title 14 of the Code of Federal Regulations, Part 91.113, the position of other coordinated air traffic is known by using an air traffic situational awareness system. In the case of uncoordinated traffic recognition, additional sensors such as primary radar are used non-intrusively. For additional redundancy, visual observers can be placed at selected locations during flight.

[0039] Figures 3A and 3B show exemplary UASs 300, 301 according to various embodiments of the present disclosure. The embodiments of UAS 300 shown in FIG. 3A and UAS 301 shown in FIG. 3B are merely exemplary. Other embodiments of the UAS can be used without departing from the scope of the present disclosure.

[0040] The UAS uses hybrid quad-rotor technology. That technology combines a fixed-wing aircraft for long-range forward flight with a quad-rotor system for vertical takeoff and landing. The hybrid quad-rotor technology gives the ability to still fly hundreds of miles to inspect an entire sub-region while enabling the launch and recovery of the UA from near an orbit or a small area of an airfield.

[0041] For BVLOS operations, examples of UASs include both the HQ-40, HQ-60B, and HQ-60C hybrid quad-rotor aircraft. The HQ-40 is a small UAS with a 10 ft wingspan. Its maximum gross weight is 45 lbs. The HQ-60B and HQ-60C are larger UASs with a 15 ft wingspan. Their maximum gross weight is 115 lbs. The HQ-60B has a longer range, longer endurance, and larger payload capacity than the HQ-40. These aircraft share not only the same flight computer and flight control software but also many of the same subsystems. Both aircraft can be operated from the same GCS. The following is an overview of both aircraft.

[0042] The HQ-40 consists of a single fuselage, a single main wing, two booms, two vertical stabilizers, and a single horizontal stabilizer. The forward flight engine is installed at the rear of the fuselage. The quad-rotor system motors are installed on the booms. The aircraft uses two struts at the front of the boom and the lower part of the vertical stabilizer as landing struts. The aircraft controls its attitude with auxiliary wings near the wingtips at the trailing edge of the main wing and an elevator on the horizontal stabilizer. The aircraft is equipped with strobe and position lights. Also, the aircraft features a highly visible paint scheme. FIG. 3A below shows the HQ-40 airframe. Tables 1 and 2 list its physical dimensions and performance characteristics.

[0043]

Table 1

[0044]

Table 2

[0045] HQ-60B consists of a single fuselage, a single main wing, two booms, two vertical stabilizers and a single horizontal stabilizer. The forward flight engine is installed at the rear of the fuselage. The quad-rotor system motors are installed on the booms. The aircraft uses structures located at the lower center of the fuselage and the lower part of the vertical stabilizers as landing struts. The aircraft controls its attitude with auxiliary wings near the wingtips at the trailing edge of the main wing, an elevator on the horizontal stabilizer, and rudders on each vertical stabilizer. Each moving wing has redundancy and is independently controlled and actuated. The aircraft is equipped with strobe and position lights. Also, the aircraft features a highly visible paint scheme. Figure 3B below shows the HQ-60B airframe. Tables 3 and 4 list its physical dimensions and performance characteristics.

[0046]

Table 3

[0047]

Table 4

[0048] Special airworthiness certifications in the experimental category have been issued for the HQ-series UAS (HQ-40 and HQ-60B), and more than 360 hours of VLOS / EVLOS operations and more than 880 hours of BVLOS operations (with 18 hours of night-time BVLOS) have been accumulated. As a result, a total flight time of 1,258 hours is obtained as of August 2017.

[0049] Figure 4 shows an exemplary command center (CC) user interface (UI) 400 according to various embodiments of the present disclosure. The embodiment of the CC UI 400 shown in FIG. 4 is merely exemplary. Other embodiments of the CC UI can be used without departing from the scope of the present disclosure.

[0050] The GCS facility comprises equipment for supporting a plurality of individual flight crews. Each flight crew can operate a single UAS in a plurality of sub - zones. Each GCS shown in FIG. 5 can include a ground - station laptop, a PC computer for launching UA - specific GCS software, a communication radio for the telemetry link, and ground - station devices including management of the wireless link and bridge between the aircraft and the operator interface, a ground - station communication antenna, and a ground - station GPS antenna.

[0051] In addition to these components, the GCS can also include devices for connectivity to a telecommunications network, equipment and interfaces for the use of railway and aviation voice radios, equipment and interfaces for communication with a flight control center, software for monitoring the location of trains, and equipment and displays for an air traffic awareness system. Also, the ground control station can include electronics tools and a backup power system capable of supporting normal operations during flight time.

[0052] The HQ-60B uses UAS autopilot (mounted on the aircraft) and a Ground Control System (GCS). This unit has been observed in DoD programs for well over 250,000 hours and has been highly successful. The autopilot software features easily definable mission parameters and limits, waypoint insertion, context menus for common functions, route copying between aircraft, easy route planning, high-performance smooth zoom 2D and 3D terrain mapping, integration of terrain databases with web mapping servers for elevation and imagery, an intuitive primary flight display, and the ability to change airspeed, altitude, and heading commands in the display. The display data can be configured as per the user's requirements. The status bar provides a high-level alert interface.

[0053] The pilot can determine the aircraft's attitude using the Primary Flight Display (PFD) on the operator interface and can determine the aircraft's position using the geographically referenced image at the center of the default display. The aircraft's position is overlaid on this image. The PFD and the aircraft's position are updated at a maximum rate of 25 Hz.

[0054] Any commands that could interfere with the normal operation of the UA are prevented by a confirmation window. Inputs that could result in undesirable outcomes are defended against. Multiple steps are required for its activation.

[0055] Figure 5 shows an exemplary Ground Control System (GCS) facility 500 according to various embodiments of the present disclosure. The embodiment of the GCS facility 500 shown in Figure 5 is merely exemplary. Other embodiments of the GCS facility 500 can be used without departing from the scope of the present disclosure.

[0056] Each flight control center may include a UAS Launch and Recovery Site (LRS). The ground crew prepares and maintains the UAs and supervises the launch and recovery operations. The HQ-60B system requires the following equipment for pre-flight preparation and post-flight activities: namely, onshore power (30 V DC power), lithium polymer (LiPo) battery safe storage, LiPo charging station (used to charge avionics and VTOL batteries), bulk fuel supply and transfer equipment, aircraft scale, tools and spare parts kit (including tools and spare parts for maintenance), launch abort system (the ground crew can abort the launch for safety reasons), web camera / VoIP equipment for communication with the flight crew in the GCS, and local C2 (command and control) radio for launch and recovery.

[0057] The ground crew and flight crew can receive training on crew roles and responsibilities and crew qualification management. Specific obligations of the ground crew are emphasized in paragraphs

[0102] to

[0128] .

[0058] Figures 6A and 6B show an exemplary telecommunication tower 600 according to various embodiments of the present disclosure. The embodiments of the telecommunication tower 600 shown in Figures 6A and 6B are merely exemplary. Other embodiments of the telecommunication tower 600 can be used without departing from the scope of the present disclosure. Figure 7 shows an exemplary radio frequency (rf) reception range analysis 700 according to various embodiments of the present disclosure. The embodiments of the rf reception range analysis 700 shown in Figure 7 are merely exemplary. Other embodiments of the rf reception range analysis 700 can be used without departing from the scope of the present disclosure.

[0059] Command and control of the UA can be accomplished using a wireless network. This command and control of the UA is independent of an example of a series of GCSs that perform handover procedures. Rather, there is one GCS connected to a network of ground-based radios spaced equidistantly along the flight path of the UA to maintain continuous communication.

[0060] To maintain the C2 link between the UA and the GCS, the UA must be within line-of-sight (LOS) of one or more antennas of this network. The antenna placement in the network is designed such that the reception ranges overlap. This means that the UA is always within the LOS of two radios along the subsector during flight. The wireless network is connected to the GCS on top of a network designed with a standby time of about 50 milliseconds.

[0061] Figures 6A and 6B show a telecommunications tower. This tower is about 300 ft high and is located at an altitude of about 1.6 NM from the orbit. This type of tower is positioned at intervals of about 15 - 30 NM along the orbit. Figure 7 shows an RF reception range analysis for a C2 wireless network using towers along the subsector. The use of seven towers provides an overlapping reception range at the orbit altitude for the entire length of the subsector. Existing towers can be used to install wireless networks along other subsectors. RF analysis and appropriate performance tests are carried out before conducting daily beyond visual line of sight (BVLOS) UAS operations for those networks.

[0062] The autopilot used in the UA features a built-in C2 / telemetry link in the ISM (Industrial, Scientific, and Medical) bands (2.4 GHz and 900 MHz). With the integration of CNPC / C2 wireless, a second C2 link is added to the aircraft. The requirement for performing normal VTOL takeoff and recovery is to have a higher bandwidth telemetry link than cruise flight. During takeoff, recovery, and local operations, the C2 link can be the 2.4 GHz wireless. When the aircraft departs from the takeoff and recovery zones, the communication link is switched by the flight crew to the CNPC / C2 wireless network.

[0063] Figure 8 shows a schematic diagram 800 of an exemplary system according to various embodiments of the present disclosure. The schematic diagram 800 of the system shown in Figure 8 is merely illustrative. Other embodiments of the schematic diagram 800 of the system can be used without departing from the scope of the present disclosure.

[0064] Figure 8 is a diagram of the communication flow. Commands, control, and telemetry data are locally transmitted in the 2.4 GHz ISM band during launch and recovery. When the aircraft establishes a cruise configuration, the UAS can enter the CNPC / C2 network through the nearest CNPC / C2 tower. The pilot makes this change using a custom software application launched on the ground station computer. This software also provides feedback to the pilot regarding the health and status of the CNPC / C2 system. If for some reason the link health of the CNPC network is not sufficient, the UA can be recovered on the local 2.4 GHz ISM link at the flight control center. If there is a problem with the local C2 health for some reason, the flight can be postponed until the problem is resolved. The health of all radios in the CNPC network can be monitored by the pilot. If the radio link health is insufficient for continued flight during cruise, the pilot can change the flight plan or execute an emergency vertical landing near the orbit.

[0065] Figure 9 shows an overview of an exemplary air traffic awareness system 900 according to various embodiments of the present disclosure. Figure 10 shows an overview of an exemplary broadcast automatic dependent surveillance - broadcast (ADS - B) site 1000 according to various embodiments of the present disclosure. Figure 11 shows an exemplary user interface display 1100 of air traffic according to various embodiments of the present disclosure. The embodiments of the air traffic awareness system 900 shown in Figure 9, the embodiments of the ADS - B site 1000 shown in Figure 10, and the embodiments of the user interface display 1100 shown in Figure 11 are merely illustrative. Other embodiments of the air traffic awareness system 900, the ADS - B site 1000, and the user interface display 1100 can be used without departing from the scope of the present disclosure.

[0066] The ability to "visually avoid" other air traffic in accordance with 91.113 of Title 14 of the United States Code of Federal Regulations is important. An air traffic situation awareness system can monitor both cooperative and non - cooperative air traffic. The components of this system can include local sensors and dispatch system and range system software tools.

[0067] As shown in FIG. 9, the dispatch system can be linked to the FAA air traffic management system (surveillance broadcast system) and also to a network of local sensors. A local network of ADS - B Xtend receivers can be installed along each sub - sector to extend the ADS - B reception range below 500 feet AGL. This example is presented in FIG. 10. By RF analysis, six additional receivers were installed on towers along the sub - sector to provide ADS - B reception range down to the ground (50 ft AGL). Note that local sensor data is not incorporated into the SBS data feed.

[0068] The range system software is an air traffic display designed to provide situation awareness to the UAS pilot. This software assists the pilot in avoiding approaches to manned air traffic (the likelihood of a manned air traffic target being able to visually identify the UA is low). By using the dispatch system, data from the FAA radar as well as data from ADS - B, ADS - R, TIS - B, and FIS - B are fused with detection values from local sensors to present the flight path of air traffic targets to the UA PIC on the range system. As shown in FIG. 11, various symbols and alert features present representations of both the UA and any air traffic target.

[0069] An example of a local sensor for the detection of non-coordinated traffic is the radar that has been tested as part of this air traffic recognition system. This radar detects personnel, ground vehicles, ships, bird targets, and low-flying aircraft. The radar configured to detect and generate the trajectories of GA aircraft-sized targets tracked a GA aircraft at a distance of 5.4 NM (10 km) with a central distance error of 20 feet (about 6 meters). The tracking time was about 70 - 110 seconds. Note that since altitude data is not available, radar tracking from this sensor is limited to two-dimensional display. Without additional adjustment, the pilot assumes that the targets are located at the same altitude and must act appropriately to avoid those targets.

[0070] For the test configuration and environment, the air traffic recognition system was set up so that the UA PIC could recognize GA air traffic (coordinated and non-coordinated) at a distance of at least 3 NM. On average, there was at least 60 seconds between its initial recognition and the closest point (between the "intruder" GA aircraft and the UA). In one study to model the visual perception of air traffic by humans, the probability of visual perception of a Piper Archer (a typical size of GA aircraft) by two pilots actively scanning air traffic was presented. The probability of visual detection was shown to be only 10% at a distance of 3 NM (the probability was shown to be 100% at less than 0.5 NM). Results from another test showed that the recognition of an intruder by the UA PIC using the distance system occurred about 17 seconds before that by a ground-based visual observer. The test results indicate that the use of the air traffic situation recognition system provides the ability to detect air traffic that is equal to or better than that of ground- or on-board visual observers.

[0071] The deployment of local sensors for non - cooperative traffic can be based on the following: (1) The ground - based ADS - B reception range along the entire length of the sub - sectors for the detection of cooperative air traffic. (2) Locations known for high density of non - cooperative air traffic. This knowledge can be obtained from the results of outreach efforts. Depending on the nature of the activities, this can lead to the deployment of sensors (radars) on a seasonal basis rather than throughout the year. (3) Risk assessment specific to the flight corridors above the tracks. The deployment can initially be based on actual air traffic data or on modeling validated by such data. Sensors or other mitigators (visual observers) can be placed in locations where the risk of mid - air collision exceeds the risk in locations where the risk of mid - air collision is considered to be within the acceptable range of the non - mitigated risk of mid - air collision (relative non - mitigated risk).

[0072] As additional air traffic avoidance technologies become operationally approved, they can be utilized. Examples of such technologies include alternative radars and onboard collision avoidance.

[0073] Two - way voice communication on aviation frequencies is an important safety mitigation. With two - way voice communication, pilots who cannot visually see each other's aircraft can inform each other of their intentions and coordinate their actions in a safe manner. The telecommunications infrastructure can use an IP wireless gateway / bridge system to host local CTAFs, towers, and approach frequencies for each sub - sector. Such a system provides push - to - talk capabilities from towers equipped with VFTF transceivers. This capability is similar to having a network of aviation ground station radios such as those used at airports for UNICOM / CTAF. In one embodiment, since the voice radios are not brought on board UA aircraft, the ground stations facilitate air - to - air communication.

[0074] This use of an aviation VHF transceiver requires FAA / FCC approval. This use is an atypical deployment of such radios. On the other hand, it has been found that its use is an important element for enabling UAS to operate BVLOS in the NAS in the same manner as manned aviation and for safely integrating UAs into the NAS.

[0075] The guidelines and procedures of the ATM (Aeronautical Information Manual) for flight under VFR are continued below. The following is an overview of the procedures for a typical flight.

[0076] The flight plan can be carried out in the same way as for manned aviation. The Pilot in Command (PIC) is familiar with all information applicable to the flight. The flight crew can use existing flight tools and information sources together with software designed for the purpose of UAS flight plans over railway infrastructure. This software uses information collected from GIS databases, site surveys, publicly available data, and approved navigation databases to assist in the development of flight plans. The flight plan can take into account mission objectives (subdivision areas, types of safety inspections, sensors), local terrain, departure and recovery sites, as well as local weather along the flight route, population along the flight route, vertical obstacles, ascent and descent paths for departure and recovery, consideration of local airspace and air traffic, gatherings of people or special events near the track. The flight fuel requirements are determined by the intended flight time. The departure time and total time in the air can be determined so that notifications can be distributed to other NAS users (DoD, Ag, GA) if necessary, and a NOTAM (Notice to Airmen) can be filed if necessary.

[0077] The outputs of the planning process are sets of GPS coordinates defining the launch and recovery locations, sets of GPS coordinates defining the landing pattern to the landing location, sets of GPS waypoints defining the flight route for normal operation, sets of GPS waypoints defining the flight route for operation under C2 link interruption, sets of GPS coordinates defining the airspace boundary (geo-fence) designed not to deviate from the railway operator's property, descriptions of suitable emergency landing areas (or areas to be avoided) within and immediately beyond the geo-fence, aeronautical charts for use on the GCS moving map display, terrain and demographic map overlays, information and procedures for transitioning through any airspace along the flight route or any airport vicinity, a schedule for issuing notifications and NOTAMs, and payload / sensor installation and fuel loading plans for the ground crew.

[0078] If the UAS PIC is convinced that flight cannot be safely conducted during any part of the flight planning process, the flight operation can be postponed until changes can be incorporated or appropriate mitigations can be implemented. Examples of where flight cannot be safely conducted include special events where large numbers of people can gather in close proximity to the trajectory, seasonal and highly localised pesticide spraying operations in close proximity to the trajectory, or the installation of new vertical obstacles at locations where loitering flight may be required.

[0079] Both the flight crew and the ground crew have responsibilities for pre-flight actions. In the GCS, the flight crew can configure all software and displays according to the pre-flight checklist. The UA configuration file can be verified. The flight plan waypoints can be loaded into the autopilot interface. Maps and map overlays can be loaded into the autopilot interface and the air traffic situation awareness system. The commonly used radio frequencies can be preset. Also, the sensor interface can be configured. Communication with the ground crew can be established at the Launch and Recovery Station (LRS). At the LRS, the ground crew can perform a pre-flight inspection of the UA, install and configure the sensors according to the flight plan, and fuel the UA. After the software and displays are configured, the ground crew cooperates with the flight crew to power on the UA system.

[0080] The flight crew and the ground crew each complete the final GCS and UA pre-flight checks, such as the transfer of the flight plan and boundaries to the autopilot, center of gravity calculation and verification, C2 and payload link checks, battery voltage check, fuel quantity verification, rotor calibration check, IMU check, VTOL system check, and the operation check of starting the pusher engine and increasing the rotation speed. By completing these tasks, the flight crew and the ground crew can be adjusted to complete the pre-takeoff checks, including visual confirmation of obstacles in the takeoff area at the flight control center. The ground crew members are in charge of the takeoff abort control. In the GCS, the flight crew can conduct the necessary pre-takeoff radio communication with ATC or notify on the CTAF. The final decision to proceed or abort can be made by the PIC.

[0081] Vertical takeoff and transition to forward flight are executed through the autopilot mode. The execution involves a series of maneuvers that occur without manual control operations by the PIC. Along with the "go" decision, a takeoff command can be issued from the GCS. During takeoff and transition, the ground crew can abort the takeoff for safety reasons.

[0082] The vertical ascent profile can bring the UA to an altitude of approximately 60 ft AGL. From there, the UA transitions to forward flight under the thrust of the forward propulsion motor. When the UA transitions to forward flight, the PIC of the GCs can verify the CNPC link integrity and admit the UA to the CNPC network. Then, the PIC can activate the flight plan. The UA proceeds to fly along the pre-programmed route.

[0083] During the cruise flight phase, the aircraft can collect the necessary data according to the flight plan to a specific target area along the trajectory. During flight, the flight crew can communicate with ATC and other NAS users and monitor the display indicating the positions of other air traffic. Also, weather, UA flight status, and system integrity (engine RPM, fuel level, battery life, GPS signal, C2 link, etc.) can be continuously monitored. The remotely measured position of the UA on the moving map can be used to ensure that the aircraft is executing the flight plan correctly. The PIC can take the initiative at any time in changing the flight plan or the course, speed, and altitude of the UA.

[0084] What is important for the safe operation of UAs in controlled airspace are procedures designed to enable BVLOS inspection missions in order to conduct manned aircraft operations safely and with minimal impact. In the case of operations in Class B, C, and D airspace, UAs, although cooperative, may not be detected by FAA radar considering their low cruise altitude. For routes affected by this issue, reporting and loitering points can be established 1.5 to 3 nautical miles on both sides of the intersection of the trajectory with the airspace boundary and the intersection of the trajectory with the runway approach path. These points can be designated and named in an agreement letter (LOA) with the control facility (such as Point Q (latitude / longitude)). Alternatively, these points can be referenced by distance and relevance to landmarks ("1.5 NM from the intersection of the route with Runway 36"). The UA PIC can call ATC on the aviation voice radio at each reporting point along the flight direction. In the case of Class D, an ATC transmission confirmation response is equivalent to obtaining approval to proceed to the next reporting point without waiting instructions. In Class B and C, a transmission confirmation response and permission to proceed must be obtained. If loitering is required at the reporting and loitering points, the UAS can fly a circuit route designed to avoid people and structures on the ground. If ATC provides an instruction to proceed to the next point with no traffic, the UA can continue its course.

[0085] Operations in Class E and Class G near airports are similar. The UA PIC can monitor the CTAF and make position reports. Based on voice radio position reports and the movement of air traffic on the air traffic situation awareness display, the PIC can use the reporting and loitering points to coordinate with manned air traffic. If necessary, the PIC can loiter at a sufficient distance from the runway centerline and wait for manned aircraft to complete their instrument approach or landing pattern.

[0086] Note that unplanned loitering or turning maneuvers can cause a lateral deviation of -1,500 ft from the + / - 100 ft corridor over the railroad operating company's property. To perform such maneuvers in a safe manner, knowledge of the vertical obstacles and local terrain within that area is required. This information can be displayed to the pilot on the GCS moving map to assist in situation awareness. Since the cruise altitude of the UA is -350 ft, the flight path is above most vertical obstacles (less than <200 ft in height) not shown on the map. If there is a risk of collision with an obstacle due to lateral maneuvers, the pilot must descend or land off - track or on - track.

[0087] Upon reaching the end of the mission, the ground crew of the LRS can be alerted to prepare the recovery site. Since the UA is close to the flight control center, the PIC can switch the C2 link from the CNPC C2 network to the local C2 network. The ground crew can clear the obstacles in the landing area and secure the landing area. The PIC can then cooperate with the ground crew to initiate the pre - defined landing pattern and approach. When reaching an altitude of approximately 60 ft within the designated distance of the touchdown point, the aircraft can transition to vertical flight and start the vertical descent to the landing point. After reaching the landing point and touching down, the aircraft can decelerate the rotation of its motor and complete the recovery phase.

[0088] After landing, the ground crew can perform a post - flight inspection of the UA in accordance with the procedure using a checklist. The ground crew can complete records such as UA flight time, VTOL and pusher motor operation time, and aircraft operating time. The maintenance records are in accordance with Title 14 of the United States Code of Federal Regulations, Part 91.417. The UAS can be stored and secured in a hangar. Data can be transferred from the on - board storage device. In the GCS, the flight crew can record the PIC / SIC flight time.

[0089] Engine Start: The autopilot features an engine stop / start switch for both the pusher motor and the VTOL motor. Both the pusher motor and the VTOL motor are set to be stopped prior to pre-flight inspection in the GCS. The switch located on the side of the fuselage is set to "off". The starting plug of the VTOL motor has been removed by the ground crew. The pusher engine start occurs at the end of the pre-flight check. First, enable the pusher engine. Next, set the switch to "on". Then, a ground crew member starts the pusher engine using the electric starter. When the pusher engine passes the pre-flight check, insert the plug for the VTOL engine. Next, enable the VTOL engine in the GCS. At that point, the ground crew can withdraw from the area near the aircraft.

[0090] Takeoff Abort: The takeoff phase of the flight can be aborted for any reason. This takeoff abort can be performed by the PIC from the GCS or from the takeoff abort control of the LRS. The takeoff abort control is a special device that can be connected to the GCS via a telecommunications network.

[0091] Link Loss Plan and Geofence Update: The link loss flight plan and the airspace boundary (geofence) can be updated as needed during long flights to ensure that the latest information is taken into account.

[0092] Weather: The UA cannot operate below the dew point temperature or in strong winds as per its limitations. Local weather observation stations, aviation weather forecasts and reports (including weather radar) can be continuously monitored by the flight crew. In case of dangerous weather conditions, abort the mission and the UA can land on or near the orbit. To recover the UA, the ground crew closest to the location can be sent out.

[0093] Pilot-in-Command (PIC): The PIC has the responsibility for the safe operation of the aircraft. The PIC can verify whether all checklist items regarding the operation of the aircraft are being followed during normal, abnormal, and emergency situations. The preflight inspection of the GCS and all flight phases (from "engine start" to "shutdown") can be the responsibility of the pilot. The decision to proceed or abort and any decisions regarding safe flight can be the ultimate authority of the PIC. This ultimate authority of the PIC includes decisions and actions regarding the operation of the UA to avoid air traffic based on the information displayed on the air traffic situation awareness system.

[0094] Second-in-Command (SIC): The SIC may have the responsibility for assisting the PIC in providing traffic warnings and weather information. The SIC can also create position reports and handle air-to-air, ATC, or emergency communications. The SIC can communicate with ATC when appropriate. If necessary, the SIC can also communicate with the entity to adjust aircraft positioning and usage.

[0095] Both the PIC and the SIC may hold an FAA private pilot license and a Class 3 aviation physical examination certificate.

[0096] Ground Crew A (GCA): The GCA may have the responsibility for ensuring that the preflight inspection of the physical aircraft and the logbook items related to the physical aircraft components are filled in. The GCA may need to verify that the necessary aircraft maintenance before flight is completed according to the applicable maintenance manual. The GCA may have the ultimate authority in determining whether the aircraft is in a flyable condition. It can be the responsibility of the GCA to "abort" the aircraft's takeoff if any abnormality or danger is observed during takeoff. During landing, the GCA may have the responsibility to order an "abort" if necessary. During recovery, the GCA can walk around the airframe after flight to conduct a thorough inspection and document any damage, abnormality, or other problems that occurred to the aircraft.

[0097] Ground Crew B (GCB): The GCB may have the responsibility for on-site access and safety and can assist the GCA as necessary. The GCB can ensure that there are no personnel, objects, and equipment in the takeoff and recovery areas for departure and entry. In the case of a malfunction or an injury to the GCA, the GCB may have the responsibility to disable the engine ignition switch while the GCA is starting the engine. After takeoff and recovery, it may be the responsibility of the GCB to ensure that all equipment related to the operation is recovered from the site and removed.

[0098] The ground crew can launch and recover the UA at night. Therefore, the ground crew can be trained to recognize and overcome the optical illusions caused by darkness and understand the physiological conditions that can reduce night vision.

[0099] The ground crew may hold an FAA A&P mechanic certificate.

[0100] The UAS-specific training program can be carried out under the instruction of a qualified instructor. The flight crew can be provided with ground schooling on the operation of all systems necessary for BVLOS operations (UA autopilot interface, C2 network control and integrity monitoring interface, air traffic situation awareness software, and aviation radio software interface). Through the ground schooling, both the flight crew and the ground crew can be trained regarding UA pre-flight inspections, UA preventive maintenance, and takeoff and recovery operations. Through flight practice, the flight crew can master normal and emergency procedures.

[0101] Personnel cannot perform flight operations without completing the documented training program. Recurrent training may include a combination of ground training and flight training.

[0102] Voice communication interruption: Voice communication among crew members is important for safety. The PIC and SIC occupy the GCS and can communicate directly with each other. The PIC and SIC can have voice communication with ground crew members at the remote launch / retrieval site via VoIP (Voice over Internet Protocol) and IP camera devices. If voice communication cannot be established or maintained, the operation can be postponed until the communication is established.

[0103] Voice communication is an important operational safety mitigation for BVLOS operations. The UA cannot enter or depart from Class B, C, or D airspace without two-way voice communication with ATC. Due to the interruption of voice communication with ATC in Class B, C, or D controlled airspace, the immediate VTOL recovery of the UA on the ground at its current location is performed. The UA cannot enter or depart from Class E airspace without two-way voice communication on the local CTAF. The UA cannot fly within 2 miles of the airport approach area without two-way voice communication on the CTAF.

[0104] Link interruption: When a C2 link interruption occurs, a warning appears on the GCS, and an audible warning is repeated along with it. This warning is triggered based on a timeout defined by the PIC. The timeout is typically 30 seconds. The autopilot processes the link interruption event using a set of parameters defined by the PIC for a given flight mission (including a flight timer that defines the maximum amount of time the aircraft can fly). The flight timer is typically based on the loaded fuel quantity or mission requirements. Also, a safe link interruption location (latitude, longitude, altitude) that the aircraft can aim for via a defined set of waypoints is defined and is called the "link interruption flight plan". When the link interruption location is reached, the aircraft can fly a circular path with a defined radius of turn. This location can be within the boundaries of the flight area and away from people or structures. In most situations, the location can be over a railway line or right next to a railway line. Attempts can also be made to restore communication with the aircraft. If this restoration is unsuccessful, several flight termination techniques can be used.

[0105] If a link interruption occurs during takeoff, the aircraft can continue its departure plan and then follow the link interruption procedure. During ascent, cruise, and descent, the aircraft can follow the link interruption procedure. During landing, the aircraft can continue to follow the pre-programmed landing plan. If the flight time (the length of the timer set by the PIC before operation) is exceeded, the aircraft can guide itself to a pre-programmed auto-landing waypoint. The aircraft can perform a VTOL landing at the auto-landing waypoint.

[0106] GPS Outage: In the event of a GPS failure, the aircraft reverts to the Inertial Navigation System (INS). Attitude and heading are maintained. Heading is determined using a magnetometer. Since aircraft position estimation is propagated, the aircraft position can drift due to errors in heading measurement and wind direction and speed estimation. If the GPS outage is temporary, the autopilot can be returned to GPS guidance when the GPS signal is regained. If the GPS outage is persistent, a flight termination can be executed.

[0107] Flyaway: An airspace boundary or geop fence can be established. In any situation where the aircraft's on-board autopilot is still functioning, but the aircraft is flying away from its planned course and does not respond to commands to return to course (most likely resulting from human error in the flight plan, communication outage, etc. in the flight plan), a flight termination due to airspace boundary violation causes a VTOL landing within 20 meters of the boundary.

[0108] Aircraft System Failure: A major UA system failure is likely to result in loss of control or a crash of the aircraft. A VTOL motor failure can typically result in a crash landing. A failure of the forward flight motor can result in a forced landing because the HQ system has the ability to automatically transition to hovering flight and land in the event of a pusher engine failure. A failure of a single flight control can result in a forced landing. A failure of multiple flight controls is likely to result in a crash landing.

[0109] GCS Failure: In the event of a GCS failure, the aircraft can continue its programmed flight plan. However, loss of functionality of the control station can ultimately result in loss of the command and control link. The aircraft can execute its link loss procedure until communication is restored.

[0110] Flight End: The flight end mode can be entered based on any of the following criteria: GPS failure (timeout), GPS and C2 link (timeout), airspace violation (based on the geofence boundary), minimum / maximum altitude violation (limit to prevent deviation above 400 ft AGL).

[0111] In addition to the above list of criteria, an intentional flight end can be executed by the PIC at any time. When entering the flight end mode, the aircraft can automatically execute an emergency VTOL recovery.

[0112] Any incident, accident, or flight operation that crosses the lateral or vertical boundaries of the flight area, or enters a restricted airspace or warning area as defined by the applicable COA, must be reported to the UAS Integration Office. Accidents and incidents must be reported to the National Transportation Safety Board (NTSB) in accordance with Title 49, Code of Federal Regulations, Section 830.5 and as directed on the NTSB website.

[0113] Quarterly after-action reports can document not only the operations conducted and activities planned for the future, but also the lessons learned from flight activities, including but not limited to anomalies encountered and impacts (if any) on airspace and other users. This information can be provided to the FAA to support future rulemaking.

[0114] In summary, the following conditions apply to BVLOS aerial inspection operations: (1) Daytime and nighttime VMC only. (2) Launch and recovery: Only from railroad operator's private land, not from airports. (3) Flight route: Cruise below 400 ft AGL (typically 350 ft AGL) above ground. Only directly above railroad operator's owned land (within a lateral boundary of + / - 100 ft from the centerline of the main track). Class B, C, D, E, and G airspace (except above airport grounds). Remote, rural, suburban, and urban areas. Enclosed by "geofence". (4) UAS: Hybrid fixed-wing configuration capable of vertical takeoff and landing (VTOL). 15-hour endurance. 750 NM range. Has +475 hours (and ongoing) of flight history and experimental category (SAC-EC) special airworthiness certification. Uses autopilot with +250,000 hours (and ongoing) by DoD systems. Equipped with Mode S transponder and ADS-B output (TSO units can be used if available). Equipped with strobe and position lights, high visibility paint scheme. Flight termination mode is emergency vertical landing. (5) 91.1 13: Aviation traffic situation recognition system that fuses FAA SBS feed and local sensors. Moving map display with targets similar to other traffic display systems. (6) Two-way voice communication: Enables coordination between pilots and ATC.

[0115] The following hazards, namely the UAS making an abnormal approach (NMAC) to a manned aircraft and the UAS colliding with a person on the ground, may result from this operation.

[0116] The risk to third parties on the ground exists when landing beyond the owned land due to loss of aircraft control. This risk is mitigated by procedures, improved visibility (so that people on the ground may be able to visually detect an approaching object), and several safety features of the UAS (including geofence and flight termination mode, designed to perform an emergency vertical landing on the railroad operator's private land (railroad tracks) under various situations).

[0117] The risk of collision with manned aircraft inherently exists in the U.S. national airspace system. A conservative approach can be taken for this assessment. Instead of addressing the risk of mid-air collision (MAC), it is possible to address the risk of near mid-air collision (NMAC). This risk of NMAC increases when the UA deviates from its planned flight route and cruising altitude or encounters a manned aircraft in an unexpected way (maneuvering in an inconsistent or unpredictable way that is not detected by the air traffic awareness system and has no response to adjustment requests via two-way voice communication, making it difficult for the UA to avoid). These situations are mitigated by flying below 400 ft AGL where air traffic density is low. Other mitigations include air traffic awareness systems, NOTAM storage (notification and coordination with DoD and other NAS users), and improved visibility (so that the pilot of a manned aircraft may be able to visually identify the UA during flight).

[0118] The following describes the models used to evaluate the safety mitigations and the impact of mitigation failures in these BVLOS operations to prevent hazards.

[0119] For this risk assessment, the main assumption is that each of the individual safety mitigations is 100% effective in preventing hazards under normal operations. If none of these mitigations fail, no hazards will occur. This is a simplified assumption used to avoid more complex modeling of the relative effectiveness of mitigations and their possible interactions.

[0120] CONOPS and Crew Effectiveness: The BVLOS CONOPS and crew training have been developed by experienced aviation experts. Their effectiveness is being continuously evaluated under the R&D flight test program. For this risk assessment, the effectiveness of the panic behind these operations and the highly trained personnel who can execute these plans is assumed to fail to prevent hazards with a 5% probability in all airspace classes.

[0121] Two-way voice communication: Voice communication is an important operational safety mitigation for BVLOS operations. Through voice communication, aircraft pilots can coordinate their activities even when they cannot see each other. However, human error is inevitable. As shown in Table 5, this mitigation is assumed to fail at a rate of 25% in all airspace classes. Also, this mitigation is assumed to have no impact on the risk of a UAS colliding with a person on the ground. Debris falling due to an in-air collision is not considered.

[0122] Air traffic situation awareness system: The ability to "see and avoid" other air traffic in accordance with 14 CFR Part 91.113 is important. The air traffic situation awareness system is not a certified ground-based detection and avoidance (GBDSAA) system. The air traffic situation awareness system can monitor and display the positions and routes of cooperative and non-cooperative air traffic. This allows the pilot of the UA to avoid nearby manned air traffic. This ability is important in uncontrolled airspace. The percentages in Table 5 were estimated under the assumption that this system is likely to fail in preventing NMACs in an environment where there may be more non-cooperative low-altitude air traffic. The failure rate ranges from 5% in Class B, C, and D airspace to 20% in Class E and Class G airspace. This mitigation is assumed to have no impact on the risk of colliding with a person on the ground.

[0123] UAS Mode S transponder with ADS-B: This device makes the UA a cooperative aircraft and allows the UAS to enter Class B and C airspace as per existing regulations (along with two-way radio communication). The percentages in Table 5 were estimated under the assumption that this system is likely to fail in preventing NMACs in an environment where there may be more non-cooperative low-altitude air traffic. The failure rate ranges from 1% in Class B and Class C airspace and 10% in Class D airspace to 20% in Class E and Class G airspace. This mitigation is assumed to have no impact on the risk of colliding with a person on the ground.

[0124] Airport Reuters Location: Procedures have been established to enhance the safety of areas near the airport. These procedures direct UA to loiter / fly Reuters at locations away from the extended centerline of the runway and the approach path to the runway when manned air traffic is in the landing pattern or in an instrument approach state. These locations are planned and known to be free of vertical obstacles. The percentages in Table 5 were estimated under the assumption that this system has a high likelihood of failing to prevent NMAC in an environment where there may be more non-cooperative low-altitude air traffic. The failure rate ranges from 10% in Class B, C, and D airspace to 20% in Class E and Class G airspace. This relaxation is assumed to have no impact on the risk of collision with people on the ground. Debris falling due to an in-air collision is not considered.

[0125] Airspace Class-Specific Procedures: Procedures for operations in various airspace classes have been developed. These procedures include standby / Reuters locations before entering / leaving controlled airspace and emergency procedures tailored to specific locations and the use of lost link flight plans to consider avoiding people on the ground, vertical obstacles, and the airport grounds. The percentages in Table 5 range from 5% in Class B and Class C airspace to 10% in Class D, Class E, and Class G airspace. This relaxation is assumed to have no impact on the risk of collision with people on the ground. Debris falling due to an in-air collision is not considered.

[0126] Pre-Flight Checklist: Proper execution of the pre-flight check ensures that the system is operating properly as designed. A fully functional system is most likely to be effective in preventing NMAC and preventing injury to people on the ground. As shown in Table 5, this relaxation is estimated to have a 25% chance of failing to prevent NMAC and prevent collisions with people on the ground in all airspace classes. Again, this is a conservative estimate, similar to assuming that the pilot community is composed of C students.

[0127] Strobe and High Visibility Paint: The UAS is smaller than a manned aircraft. High visibility paint, strobes, and position lights increase the likelihood that other pilots and people on the ground can visually detect the UAS, especially at night. For this risk assessment, it is assumed that in the event of a failure to improve the visibility of the UA, there is a 10% chance of being unable to prevent a NMAC and a 90% chance of being unable to prevent a collision with people on the ground. This implies that people on the ground are more likely to be able to act based on visualizing the lighting and paint scheme than the pilot of a manned aircraft.

[0128] NOTAM: Notification to aviation personnel informs other NAS users about UA flight activities. This NOTAM has the highest likelihood of preventing a NMAC if it is issued in a timely manner and other NAS users read and interpret it correctly. For this risk assessment, failure to issue, read, understand, and comply with or correctly use the information in the NOTAM can result in human error and thus is assumed to have a 25% probability of failing to prevent harm.

[0129] Table 5 below lists the safety mitigations presented above, along with an estimate of the likelihood that failure of that mitigation will result in failure to prevent a harmful outcome.

[0130]

Table 5

[0131] A system failure that causes a loss of control leading the UA to deviate from its planned course is likely to result in the hazards listed above. These failures and events were developed using knowledge (UAS subsystems, how they fail, and what happens when they fail). Failure conditions are listed below along with the resulting deviation from the planned course over the private property of a railroad operator.

[0132] For this risk assessment, the two main assumptions regarding system failures are that the probability of a single system failure is 0.01 (1%) and the probability of multiple failures is 0.0001 (0.01%) (the failure rate is per hour).

[0133] Flyaway: In any situation where the aircraft's on-board autopilot is still functioning, but the aircraft is flying away from its planned course and does not respond to a command to return to course (most likely resulting from human error in the flight plan, communication interruption, etc. in the flight plan), VTOL landing is performed within 20 meters from the boundary due to the end of the flight by airspace boundary violation. The maximum deviation is 166 ft.

[0134] Ground Control System (GCS) failure: In the event of a GCS failure, the aircraft can continue its programmed flight plan. However, the loss of functionality of the control station can ultimately result in the interruption of the command and control link. The aircraft can execute its link interruption procedure and ultimately perform a controlled landing on the property of the railway operating company. For example, the landing zone is 66 ft in diameter and is within the + / - 100 ft corridor of the private land of the railway operator.

[0135] GPS interruption: In the event of a GPS failure, the aircraft reverts to the Inertial Navigation System (INS). The attitude and heading are maintained. The heading is determined using a magnetometer. Since the aircraft position estimate is propagated, the aircraft position can drift due to errors in heading measurement and wind direction and speed estimation. If the GPS interruption is temporary, the autopilot can be returned to GPS guidance when the GPS signal is regained. If the GPS interruption is persistent, the flight can be terminated. The deviation is 66 ft.

[0136] Link Loss: Command and Control (C2) When a link loss occurs, a warning appears on the GCS, and an audible warning is repeated. This warning is triggered based on a timeout defined by the pilot. The timeout is typically 30 seconds. The autopilot processes link loss events using a set of parameters defined by the pilot for a given flight mission (including a flight timer that defines the maximum amount of time the aircraft can fly). The flight timer is typically based on the amount of fuel loaded or mission requirements. Also defined is a safe link loss location (latitude, longitude, altitude) that the aircraft can aim for via a defined set of waypoints, called the "link loss flight plan". When the link loss location is reached, the aircraft can fly a circular path with a defined radius until the flight timer expires. If a link loss occurs during takeoff, the aircraft can continue its departure plan and then follow the link loss procedure. During ascent, cruise, and descent, the aircraft can follow the link loss procedure. During landing, the aircraft can continue to follow the pre-programmed landing plan. If the flight time (the length of the timer set by the PIC before operation) is exceeded, the aircraft can guide itself to a pre-programmed auto-landing waypoint. The aircraft can then perform a VTOL landing. The landing zone is 66 ft in diameter and is within a + / - 100 ft corridor of the railroad operator's private land.

[0137] Voice Communication Loss: Voice communication is an important operational safety mitigation for BVLOS operations. The UA cannot enter Class D or C airspace or depart from within Class D or C airspace without two-way voice communication with ATC. A loss of voice communication with ATC in Class D or C controlled airspace results in an immediate VTOL recovery of the UA at its current location on the ground. The UA cannot enter Class E airspace or depart from within Class E airspace without two-way voice communication on the local CTAF. The UA cannot fly within 2 miles of the airport approach area without two-way voice communication on the CTAF. The landing zone is 66 ft in diameter and is within a + / - 100 ft corridor of the railroad operator's private land.

[0138] Power System Distribution Failure: Unlike larger transport aircraft that have redundant power distribution systems, there is only one power distribution system. With battery backup, some power loss scenarios are excluded. Connector and cable wiring problems that can cause power distribution losses should be identified prior to flight through preflight and regular maintenance inspections. A complete loss of power can lead to autopilot failure and may cause the ignition of the pusher engine to stop. Without power from the forward flight engines and the ability to receive control inputs, a statically stable aircraft can glide along a trajectory determined by the final control surface position prior to failure. In the worst case, with a glide ratio of approximately 8:1, the aircraft will continue straight flight for approximately 3,200 linear feet and then crash into the ground.

[0139] In-Flight Computer Failure: There is only one flight computer / autopilot. If this computer fails, the forward flight engines will automatically stop due to the so-called dead man circuit on the power distribution panel. This is a safety feature of the autopilot connected to the forward flight engine ignition. If the dead man circuit loses the hardware signal from the autopilot, the engine will stop. Without power from the forward flight engines and the ability to receive control inputs, a statically stable aircraft can glide along a trajectory determined by the final control surface position prior to failure. In the worst case, with a glide ratio of approximately 8:1, the aircraft will continue straight flight for approximately 3,200 linear feet and then crash into the ground.

[0140] The assumption for this failure scenario is that the in-flight computer experiences a "hard" failure where the autopilot function is not available. Note that the engine shutdown prevents a true flyaway condition.

[0141] The worst-case scenario is one in which some combination of several functions within the flight computer fails, but the UA is still capable of controlled flight without responding to pilot commands. Here, the UA can fly until it runs out of fuel. The UA has a range of at least 450 NM (27,337,750 feet). According to the developers of the autopilot, this failure has never occurred in the operating history of this unit.

[0142] IMU sensor failure: The aircraft has only one IMU and no redundant sensors (gyroscopes, accelerometers). A failure that provides incorrect data can lead to uncontrollable flight. There may be no possibility of an emergency VTOL landing. During flight, the system status is monitored. If a sensor failure results in inconsistent flight behavior, the pilot can initiate the end of the flight and make an emergency landing on or near the property. However, the results can vary depending on the sensor failure. In the case of this failure, the deviation is assumed to be 600 ft.

[0143] Atmospheric data system failure: Loss of the atmospheric data system can result in inaccurate altitude and airspeed readings. The aircraft can climb or descend (depending on the failure). However, the aircraft can still stay on its flight path. The aircraft can experience an aerodynamic stall due to an incorrect high airspeed reading. In this case, the aircraft may stall and fall near its current location. An alternative example is that the airspeed is incorrectly low, and the aircraft makes a steep descent in accordance with the airspeed and collides with the ground. In either case, navigation within the horizontal plane is maintained. A long-term loss of atmospheric data can lead to loss of control of the aircraft.

[0144] To ensure the availability of this system, there is a pre-flight check to verify the airspeed sensor function. During flight, the air data system status is monitored. If an air data system anomaly is quickly identified during flight, the aircraft can land on the property of the railroad operating company. The landing zone is 66 ft in diameter. This is within a + / - 100 ft corridor of the railroad operator's private property.

[0145] Air traffic situation awareness system failure: Loss of SBS data feed and / or loss of the local sensor network or local sensor failures that compromise the data fusion function can result in inaccurate representation of air traffic. As a result, mid-air collisions can occur. The flight crew can monitor the system's integrity. This includes monitoring system indicators, the progress of cooperative and non-cooperative target tracks, and time synchronization with the system server. If an anomaly is quickly identified during flight, the aircraft can land on the property. The landing zone is 66 ft in diameter. This is within a + / - 100 ft corridor of the railroad operator's private property.

[0146] Propulsion failure: In the event of a propulsion system failure while the autopilot is still functioning, the pilot can control the landing. By turning at a 20-degree bank angle, the UA can descend with a turning radius of 665 ft.

[0147] Table 6 below summarizes the amount of deviation from the most likely flight path corridors that occur when a single failure occurs (on the diagonal of the table) and when two failures occur. This information can be used to develop the probabilities in Table 7 below. Table 7 can be used in item 6 to determine the risk of the UAS colliding / crashing into people on the ground.

[0148]

Table 6

[0149] Using the information developed above, the occurrence rates of three different sized deviation incidents are estimated. The first size is a deviation of 166 ft. The second size is a deviation of 3,200 ft. The third size is a longer deviation (where the UAS is considered to be errant or out of control (flyaway scenario)). Any deviation less than 100 ft from the course is considered a normal part of the UAS operation.

[0150] Table 7 shows the percentage of different deviations occurring based on this analysis. Note that the most likely to occur (overall) are those up to 3,200 ft (but greater than 166 ft). However, under a single failure, the UAS is most likely to experience no deviation at all.

[0151]

Table 7

[0152] As described above, it is assumed that the probability of a single failure occurring per flight hour is 0.01 and the probability of multiple failures occurring is 0.0001 (1% and 0.01% respectively). Therefore, combining these assumptions with the estimates in Table 7, the probability of deviation from the specified path for different deviation sizes can be estimated. These are listed in Table 8.

[0153]

Table 8

[0154] Based on this analysis and due to the design of this UAS, shorter deviations are far more likely to occur than large errant deviations. The probability of an errant deviation failure is of such a magnitude that it is currently ignored as it is lower than the other two probabilities. Therefore, the probability of a deviation incident is P DI = 9.22×10 -4 + 1.88×10 -3 = 2.80×10 -3It is as follows.

[0155] The following items will explain the assumptions and considerations for the method to calculate the assumptions and related risks used in the analysis of abnormal proximity.

[0156] The main assumptions in this analysis are as follows. (1) Air traffic density is correlated with airspace classes. That is, Class B has the most traffic, followed by Classes C, D, and E. Class G has the lowest traffic density. (2) Air traffic density is lower below 400 ft AGL. (3) Air traffic below 400 ft is uniformly disrupted within a given airspace class. (4) Deviation incidents are not considered in the determination of NMAC risk.

[0157] An Abnormal Proximity (NMAC) as defined by AIM (7-6-3) is "an incident associated with the operation of an aircraft in which a report stating that a collision potential existed as a result of a proximity of less than 500 feet to another aircraft, or that a risk of collision existed between two or more aircraft, was received from a pilot or flight crew member."

[0158] For this risk assessment, the NMAC volume is modeled as a sphere around the aircraft. NMAC occurs when the spheres surrounding two aircraft intersect. The NMAC volume for a UA is a sphere with a radius of 500 ft. Since a UA has a wingspan of approximately 15 ft, this sphere encloses the UA itself and includes a 500 ft buffer. The NMAC volume for a manned aircraft is a sphere with a radius of 700 ft. Since the wingspan of a commercial aircraft is approximately 200 ft, this sphere encloses the largest manned aircraft and also includes a 500 ft buffer.

[0159] For this risk assessment, air traffic is assumed to be uniformly disrupted within a given airspace class. This assumption enables the calculation of the likelihood of collisions using a basic geometric (spatial) model. Under this assumption, the airspace is modeled as a collection of grid cells. Within each cell, air traffic is approximated as having a constant density.

[0160] Also, according to 14 CFR 91.119, except for the airspace directly surrounding an airport, it is also assumed that the air traffic density is lower for altitudes below the field perimeter route altitude (about 800 ft AGL) and even for altitudes below 400 ft AGL.

[0161] In reality, there are areas with higher aircraft densities. Aircraft are likely to follow specific routes (Victor airways, IR and VR routes, and direct courses between airports). Typically, the density is higher near airports (especially near populated areas and where Class C and B airspace designations are approved). However, this environmental variation can only be considered with location-specific data. That data is not readily available and requires more complex modeling.

[0162] Table 9 provides the estimated frequency of air traffic in different airspace classes in units of aircraft per cubic mile per hour. These values can be used to calculate the exposure to the risk of abnormal proximity in different airspace classes.

[0163] [Table 9]

[0164] Figure 12 shows an exemplary unmitigated abnormal proximity risk 1200 according to various embodiments of the present disclosure. The embodiments of the unmitigated abnormal proximity risk 1200 shown in Figure 12 are merely exemplary. Other embodiments of the unmitigated abnormal proximity risk can be used without departing from the scope of the present disclosure.

[0165] The in - hour (per hour) air traffic frequency within 1 cubic mile is applied to cells of 1 nm×1 nm×800 ft. With the reduction of this area, the air traffic density value becomes a conservative estimate. An abnormal approach occurs when one aircraft intrudes into the other's NMAC volume. To estimate this probability, Monte Carlo simulation was performed. One billion pairs of random points were selected within the airspace cells as shown in Figure 12. The percentage of these point pairs with a distance less than 700 ft was calculated. The criterion for NMAC was met at a rate of 39%. This value of 3.9×10 -1 can be called the geometric risk for NMAC. This represents the unmitigated risk of abnormal approach for all airspace classes.

[0166] It should be noted that this is a very conservative estimate. NMAC events are assumed to occur in all cases where the distance is less than 1,200 ft (less than 500 ft is a dual NMAC event). However, in reality, due to following the trajectory, any value less than 1,200 ft would already trigger an NMAC event for manned aircraft. This is an artifact of the Monte Carlo simulation.

[0167] Again, the main assumption of this risk assessment is that the safety mitigations adopted for these operations are fully effective. If none of them fail, NMAC will not occur.The worst - case scenario is when all possible mitigation system failures occur under the assumptions of Table 5. Table 10 below presents the probabilities of NMAC for different airspace classifications using the above values and exposure assumptions.

[0168]

Table 10

[0169] FIG. 13 shows an exemplary pedestrian risk zone 1300 according to various embodiments of the present disclosure. The embodiment of the pedestrian risk zone 1300 shown in FIG. 13 is merely exemplary. Other embodiments of the pedestrian risk zone can be used without departing from the scope of the present disclosure.

[0170] The following items will describe the considerations regarding the assumptions and related risks used in the analysis of a collision with a person on the ground and the method for calculating them.

[0171] The main assumptions in this analysis are as follows. (1) All people on the ground are unprotected. (2) The ground population is correlated with the airspace class. That is, class B is located in a metropolitan area. Class C is located in an urban area. Class D is located in a suburban area. Classes E and G are located in rural areas. (3) The ground population is uniformly obstructed within a given airspace class. (4) Any individual on a railway line is an active participant in the operation. An intruder is not considered a special case. That is, the intruder is engaged in illegal activities and accepts the related risks. (5) A person crossing a road is assumed to be unprotected and is considered in a uniform distribution of population density. This is a conservative estimate. (6) A course deviation incident is considered in the determination of the risk to a person on the ground.

[0172] For this risk assessment, the population is assumed to be uniformly disrupted within a given airspace class. This assumption enables the calculation of the probability of collision using a basic geometric (spatial) model. Considering the flight path of the UAS operation, the ground risk zones are modeled on both sides of the path as shown in Figure 13. The length of each zone segment is 1 mile, and the width is determined by the glide capability of the UAS. In one embodiment, the UA can glide 3,200 ft from a starting altitude of 400 ft AGL. The geometric risk for one pedestrian per mile is the ratio of the area of a typical human to the area of the segment in question. For the calculation, the area of a human (seen from above) is assumed to be 2.25 square feet. The resulting geometric risk value is 6.66×10 -8 per segment.

[0173] Considering the flight route, the population density along the route can be estimated in the area directly adjacent to the path. For this risk assessment, the population densities associated with different airspace classes are estimated based on exemplary census data for representative areas. Table 11 lists these population estimates.

[0174]

Table 11

[0175] Considering the worst-case scenario where all mitigation systems fail, Table 12 gives the probability of collision with a human for different airspace classes, calculated using the assumed population per segment for the assumed population values. These values are the population densities of the segments to which the geometric risk applies and reflect the magnitude of the unmitigated risk of collision with a human. A more accurate analysis would use a portion of the census block data collected along a specific flight path (or data from another source such as a land scan).

[0176]

Table 12

[0177] The main assumption of this risk assessment is that the safety mitigations employed for these operations are fully effective. If none of them fail, NMAC will not occur. The worst-case scenario is when all of the mitigation system failures that could occur under the assumptions of Table 5 occur. Table 13 below presents the probability of collision with people on the ground for different airspace classifications using the above values and assumptions.

[0178]

Table 13

[0179] The probability of collision with people on the ground is also assumed to depend on the incidents that occur. A UAS cannot collide with a third-party person unless it deviates from its course. Therefore, a method for evaluating the reliability of a UAS beyond the mitigation systems discussed must be developed. In general, this is a difficult task because very limited or no data exists for accurately assessing the reliability of UAS components. Therefore, estimations must be made.

[0180] Therefore, here, P SH =PSH\DIP DI can be calculated (P DI is defined in paragraphs

[0177] and

[0178] above). Table 14 is presented to include the probability of a deviation incident.

[0181]

Table 14

[0182] Some estimations are that the inherent risk of NMAC for general aviation VFR flight in the NAS is approximately 1.33×10 per hour -7This suggests that. This risk assessment using conservative assumptions indicates that the proposed BVLOS operation is of the same level of existing risk and cannot substantially increase the risk in the NAS.

[0183] The estimated risk of death due to a falling object hitting is approximately 1.44×10 per hour -9 (3×10 per year -6 ) 2 This is. This risk assessment using conservative assumptions indicates that the proposed BVLOS operation does not substantially increase the risk to people on the ground. Table 15 provides a summary of the operational risk analysis.

[0184]

Table 15

[0185] Figure 14 shows an exemplary safety corridor airspace (SCA) interface 1400 according to various embodiments of the present disclosure. The embodiments of the SCA interface 1400 shown in Figure 14 are merely exemplary. Other embodiments of the SCA interface 1400 can be used without departing from the scope of the present disclosure.

[0186] Figures 15A, 15B, and 15C show exemplary defective rail states 1500, 1501, and 1502 according to various embodiments of the present disclosure. The embodiments of the defective rail states 1500, 1501, and 1502 shown in Figure 15 are merely exemplary. Other embodiments of the defective rail states 1500, 1501, and 1502 can be used without departing from the scope of the present disclosure.

[0187] The defective state 1500 is called a broken rail or rail gap. The defective state 1500 is caused by rapid cooling in the area where the rail is separated.

[0188] Defect state 1501 is called the mixing of fine-grained soil into the ballast. Defect state 1501 is caused by the sediment on the macrogirder of the rail. The mixing of fine-grained soil into the ballast causes erosion of the base of the rail and the macrogirder. Since the ballast takes in the load of the train from the rail, due to the sediment, the ballast can no longer make the rail very tolerant. Due to the lack of tolerance, stress is generated on the components (such as macrogirders) of the rail, and there is a potential risk of loosening or coming off the rail. The mixing of fine-grained soil into the ballast can be determined when new things that are not ballast seem to spread in the image or when the macrogirder is covered.

[0189] Defect state 1502 is called a curved rail, a wavy rail, or a misaligned rail. Defect state 1502 is caused by the cutting movement of the rail due to rapid heating. The rail expands to a certain extent due to heat, and thereby the rail is pushed out. Due to the expansion of the rail, a deviation in the measured value between the rails occurs.

[0190] Defect states 1500, 1501, and 1502 can be detected by comparing the image with the image of the previous rail, and also by comparing the image with one image or a series of images of the rail taken previously.

[0191] All of those defect states 1502 are analyzed for changes such as pixel coloring, pixel density, and the amount of pixels (indicating distance) between components. The changes are identified when one of the changes occurs between a series of images of a single flight, and also when one of the changes occurs in the images of the same rail from different UAV flights.

[0192] Also, the defect state can be detected based on specific measured values. For example, one of the standards for the rail width is 1435 mm (4 ft 8.5 in). In this embodiment, when the captured image shows that the rail deviates from 1435 mm, the curved rail defect state 1502 is detected.

[0193] To avoid false detection or non-substantive detection, a threshold can be assigned to each defect state 1500, 1501, and 1502. For example, one of the standards for the gap between consecutive rails is 14.30 mm. To include the tolerance range, the gap threshold can be 14.50 mm. When a gap is detected to be less than 14.50 mm, the system will not identify the gap.

[0194] Also, the system can identify the length of each rail and use that length to verify different gaps. For example, one of the standards for the length of a rail is 39 ft. For a rail of this length, the system can use the gap threshold within the range corresponding to each rail. In an embodiment of a 39 ft rail, the system can use the gap threshold to account for the gap between the rails, but use a much smaller gap threshold between those ranges. For example, the system uses 5 mm as the gap threshold for those with a distance from the end of the rail exceeding 1 ft, and uses a gap threshold of 15 mm for those with a distance from the end of the rail of 1 ft or less.

[0195] Also, the system can also make a determination or perform a defect based on the criticality of the defect. A certain defect can be regarded as critical or warning. A critical defect is a defect that potentially derails, damages the train, or significantly hinders the movement of the train. A warning defect is a defect that requires maintenance but does not pose a risk of train derailment, damage, or significant interference.

[0196] FIG. 16 shows an exemplary concept of operation 1600 according to various embodiments of the present disclosure. The embodiment of the concept of operation 1600 shown in FIG. 16 is merely exemplary. Without departing from the scope of the present disclosure, other embodiments of the concept of operation 1600 can be used.

[0197] Different concepts of operation 1600 include, but are not limited to, auxiliary tunnel and bridge inspection 1605, continuous asset overflight 1610, auxiliary track inspection 1615, and auxiliary track integrity flight 1620.

[0198] FIG. 17 shows an exemplary UAS ecosystem 1700 according to various embodiments of the present disclosure. The embodiments of the UAS ecosystem 1700 shown in FIG. 17 are merely exemplary. Other embodiments of the concepts of the UAS ecosystem 1700 can be used without departing from the scope of the present disclosure.

[0199] The UAS ecosystem includes a satellite 1705, a GPS module 1710, a propeller 1715, a flight controller 1720, a motor controller 1730, a motor 140, a frame 1745, LED positioning lighting 1750, an RC receiver 155, a remote controller 1760, a camera mount 1765, a camera 1770, a live image broadcast 1775, virtual reality goggles 1780, a lithium polymer battery 1785, and the like.

[0200] The satellite 1705 enables communication between the UAS and the flight control center.

[0201] The GPS module 1710 is a device that can receive location information from GPS satellites. The GPS module is used for both tracking the UAS and enabling the UAS to follow a programmed flight plan.

[0202] The propeller 1715 is rotatably coupled to the UAS and provides lift to the UAS. The propeller is used for takeoff and landing purposes. The UAS may include a plurality of propellers.

[0203] The flight controller 1720 includes programming for a flight plan for takeoff and landing of the UAV. The flight controller 1720 is installed on the UAS. The flight controller 1720 controls the propeller according to the flight plan.

[0204] The motor controller 1730 is included in the UAS. The motor controller 1730 controls the motor 140 for this purpose.

[0205] The motor 140 provides forward thrust for the UAS. The UAS may include a plurality of motors 140.

[0206] The frame 1745 of the UAS provides support and protection for the components of the UAS. The frame 1745 is structured such that the UAS can continue to glide in the event of a failure of a thrust or lift component or system.

[0207] The LED positioning lighting 1750 is installed on the UAS. The LED positioning lighting 1750 provides a display of the UAS to other aircraft and identifies the location of the UAS. Also, the LED positioning lighting is beneficial for low visibility environments such as tunnels, fog, and at night.

[0208] The RC receiver 1755 is a wireless receiver built into the UAS. The RC receiver can communicate with a tower or other satellite to receive signals. The command center transmits signals to the UAS through the RC receiver 1755.

[0209] The remote controller 1760 is installed on the frame 1745 of the UAS or communicates through the RC receiver 1755. The remote controller 1760 can load a flight plan before flight, or receive an updated flight plan, or be a controller through the RC receiver 1755.

[0210] The camera mount 1765 is used to mount the camera 1770. The camera mount 1765 provides support for the camera 1770. The camera mount 1765 can be attached to the base of the frame 1745.

[0211] The camera 1770 is used to capture images and video data of railway lines. A plurality of cameras and different types of cameras can be attached to the UAS.

[0212] Camera 1770 is used to identify the route network for monitoring. Also, the railway image can also be used to adjust the flight plan. In other words, if the location of the UAV from the flight plan is not confirmed by the image, the flight plan can be adjusted. Also, the UAV can send a difference display indicating the difference between the determined location from the flight plan or sensor and the determined location from the image to the command center.

[0213] Also, camera 1770 is used to identify defects in the railway line. Camera 1770 can detect obstacles on the rails such as an engine stopped or parked on the track, garbage or other debris. When detecting defects, camera 1770 can be used to capture an image of the rail to be analyzed for broken rails / rail gaps 1500, fine-grained soil contamination of ballast 1501, curved rails 1502, etc.

[0214] Live image broadcast 1775 is executed using camera 1770 and RC receiver 1755. The image / frame captured by camera 1770 can be broadcast to the command center or the like. Live image broadcast can provide real-time images or videos for the user to further analyze the defect situation.

[0215] Virtual reality goggles 1780 can be used by the operator on the ground or at the command center. The virtual reality goggles can display the live image broadcast 1775 from camera 1770.

[0216] The lithium polymer battery 1785 is built into the frame 1745 of the UAS. The battery 1785 can be used to supply power to different components of the UAS.

[0217] Figure 18 shows an exemplary UAS system component 1800 according to various embodiments of the present disclosure. The embodiments of the UAS system component 1800 shown in Figure 18 are merely exemplary. Other embodiments of the UAS system component 1800 can be used without departing from the scope of the present disclosure.

[0218] The UAS system component 1800 includes, but is not limited to, software 1805, a UAS 1810, a tracker control module 1815, an autopilot 1820, a laser altimeter sensor 1825, a rack-mounted ground control station 1830, and the like.

[0219] The software 1805 can be installed on the UAS and at the command center. The software 1805 can execute any of the functions described in this application.

[0220] The UAS 1810 is an unmanned aircraft system. The UAS flies over the railway line to monitor the integrity of the track. The UAS also monitors for obstacles on the rails.

[0221] The tracker control module 1815 tracks the UAS during operation. The tracker control module 1815 includes a flight plan and can detect when the UAS deviates from the flight plan. The tracker control module 1815 can update the flight plan, determine problems with the UAS itself, or display an alarm to the user at the command center.

[0222] The autopilot 1820 controls the UAS 1810. The autopilot 1820 can be installed on the UAS or on the ground and send commands through an RC receiver.

[0223] The laser altimeter sensor 1825 determines the altitude of the UAS 1810. The laser altimeter 1825 communicates with the command center.

[0224] The rack-mounted ground control station 1830 provides a command center for the UAS 1810. The control station 1830 can control the flight plan of the UAS and monitor the UAS while the flight plan is being executed.

[0225] Figures 19A, 19B, and 19C show exemplary UASs 1900, 1905, 1910 according to various embodiments of the present disclosure. The embodiments of the UASs 1900, 1905, 1910 shown in FIG. 19 are merely exemplary. Other embodiments of the UAS can be used without departing from the scope of the present disclosure.

[0226] Figure 20 shows an exemplary optical sensor 2000 according to various embodiments of the present disclosure. The embodiment of the optical sensor 2000 shown in FIG. 20 is merely exemplary. Other embodiments of the optical sensor 2000 can be used without departing from the scope of the present disclosure.

[0227] [[ID=]12]Figures 21A and 21B show exemplary UAS safety boundaries 2100, 2101 according to various embodiments of the present disclosure. The embodiments of the UAS safety boundaries 2100, 2101 shown in FIGS. 21A and 21B are merely exemplary. Other embodiments of the UAS safety boundary can be used without departing from the scope of the present disclosure.

[0228] Figures 22A and 22B show exemplary trajectory integrity sensor images 2200, 2201 according to various embodiments of the present disclosure. The embodiments of the trajectory integrity sensor images 2200, 2201 shown in FIGS. 22A and 22B are merely exemplary. Other embodiments of the trajectory integrity sensor image can be used without departing from the scope of the present disclosure.

[0229] In images 2200 and 2201, the UAS is monitoring the rail 2205. The UAS inspects for possible failures at each joint 2210.

[0230] Figures 23A, 23B, 23C, and 23D show exemplary potential rail head defects 2300 according to various embodiments of the present disclosure. The embodiments of the potential rail head defects 2300 shown in FIG. 23 are merely exemplary. Other embodiments of potential rail head defects can be used without departing from the scope of the present disclosure.

[0231] Images 2300, 2305, 2310, and 2315 show defects in the rail detected by the UAS. In the first image 2300, the UAS system detects possible defects. The UAS system zooms in on the rail to capture image 2305. The UAS system repeats the display zoom for images 2315 and 2320 until the defective or non-defective state is identified and confirmed. The non-defective state is when it is determined that no repair of the rail is required.

[0232] FIG. 24 shows an exemplary block diagram of a control network 2400 according to various embodiments of the present disclosure. The embodiments of the control network 2400 shown in FIG. 24 are merely exemplary. Other embodiments of the control network can be used without departing from the scope of the present disclosure.

[0233] The control network 2400 includes, but is not limited to, a fixed operator location 2405, a field operator location 2410, an autopilot 2415, a UAS 2420, a wired network 2425, a tower 2430, an airborne radio 2435, etc. The control network 2400 is used to monitor defects or obstacles on the railroad track. The airborne radio 2435 communicates with another aircraft 2440, which can be manned or unmanned.

[0234] The fixed operator location 2405 is a permanently located command center. The fixed operator location 2405 can be connected to the tower 2430 by wire or wirelessly for communication with the UAV.

[0235] The field operator location 2410 is a temporarily located command center. In other words, the field operator location 2410 is located far from the command center and can monitor the UAS on-site. The field operator location 2405 can be wirelessly connected to the tower 2430 for communication with the UAS 2420. Also, the field operator location 2410 can communicate directly with the UAS or directly control the UAS without using the tower. Further, the field operator location 2410 can communicate with the fixed operator location 2405.

[0236] Also, although the autopilot 2415 is shown to be located at the field operator location 2410, it can also be located at the fixed operator location 2405. The autopilot 2415 is used to control the UAS 2420.

[0237] The UAS 2420 flies over the railway line and monitors for defects or obstacles. Also, the UAS 2420 can include the autopilot 2415. The UAS 2420 can communicate directly with the autopilot 2415 (when located at the field operator location 2410), or with the system at the field operator location 2410, or with the tower 2430.

[0238] The UAS 2420 can be programmed to maintain communication with multiple towers (e.g., at least two towers). This would mean that it would be necessary to transition to a third tower before disconnecting from one of the two connected towers. The UAS 2420 (or the autopilot 2415, the system at the fixed operator location 2410 or the field operator location 2405) can determine the number of towers or which tower to connect to based on signal strength, signal quality, etc.

[0239] The wired network 2425 connects a fixed operator location to a plurality of towers 2430. Each of the towers 2430 is individually connected to other towers through the wired network 2425. Since the towers 2430 are connected to the wired network 2425, the field operator location 2410 can maintain communication with the UAS 2420 even after the UAS has flown out of the range of the wireless signal of the field operator location 2410.

[0240] The tower 2430 transmits and receives wireless signals to and from the UAS, other towers 2430, and the system of the field operator location 2410. The tower 2430 is also connected to the wired network 2425 for communication with the fixed operator location 2405 and other towers 2430.

[0241] FIG. 25 shows an exemplary railroad right-of-way / air system control network 2500 according to various embodiments of the present disclosure. The embodiment of the railroad right-of-way / air system control network 2500 shown in FIG. 25 is merely exemplary. Other embodiments of the railroad right-of-way / air system control network can be used without departing from the scope of the present disclosure.

[0242] The railroad right-of-way / air system control network 2500 includes, but is not limited to, a UAS 2505, a first tower 2510, a second tower 2515, a ground control system 2520, an automatic control 2530, an RTK 2545, a tower wireless transceiver 2550, a UAV wireless transceiver 2555, an automatic control 2560, etc.

[0243] Long-range UAS deployments have been noted in military activities in military airspace or combat zones in foreign countries where commercial aviation regulations are not as prevalent. Airport location accuracy, terrain avoidance, communication / command and control latency, and aircraft payload considerations are fundamentally different and are often not applicable to commercial, low-altitude, domestic use.

[0244] In the development of methods / means for pursuing long-distance flight operations, a system solution with several key features was created.

[0245] First, the control network 2500 is capable of taking in FAA air traffic data (if available) and merging that data with additional air traffic and obstacle data (dedicated geospatial data installed at various tower sites along railroad rights-of-way and collected from auxiliary aviation voice / data receivers).

[0246] Second, the control network 2500 assembled in Figure 25 provides wayfinding guarantees for both aircraft below 500 ft AGL and various data collection sensors to mission planners and pilots. The wayfinding guarantees assist with terrain avoidance, wayfinding accuracy, sensor / payload focus, and location accuracy as well as ground altitude verification. The components of RTK 2545, UAS 2505, PCC 2530, tower wireless transceiver 2550, UAV wireless transceiver 2555, ground control system 2520, first tower 2510, and second tower 2515, overall, provide this awareness for remote plotting such that an opinion can be held regarding the aircraft's performance, environment, flight accuracy, sensor performance, and compliance with FAA air regulations and our flight requirements. Finally, in the event of an emergency or malfunction, the system, overall, enables the pilot to safely land the aircraft on the railroad right-of-way.

[0247] Third, in addition to the network used for data transmission / reception between tower wireless receiver 2550 and UAV wireless receiver 2555 and autopilot 2560 and ground control 2520, an aviation band radio 2435 is installed at almost all airports (within the vicinity of 2510 and 2515). The aviation band radio 2435 provides the pilot with the ability to communicate with other aircraft near the airport and thereby avoid low-altitude encounters near airports without local / control towers (an important safety feature and something very unique to this deployment).

[0248] Figure 26 shows an exemplary process for inspecting railway assets using an unmanned aerial vehicle according to various embodiments of the present disclosure. For example, process 2600 can be executed using a UAS.

[0249] In operation 2605, the system performs railway vision information processing. Railway vision information processing includes locally or remotely processing images to detect obstacles or defects on the railway line. Railway vision information processing also includes locally storing the results and transferring the results for archiving at the command center. The system transmits a flight plan including the railway line and the flight path via a plurality of communication towers. The railway line can include multiple railways over a geographical location. The flight path is the path along which the UAV moves to monitor the railway line. The flight path can include flying along the track, flying around the bridge, flying through the tunnel, etc. The flight path can have a start and end point at a set location or different locations.

[0250] In operation 2610, the system monitors the railway line for detection of track components and other features. The system can receive data while the UAV is monitoring the railway line via a plurality of communication towers. The UAV can be connected to a plurality of towers (at least two towers). The communication towers can be connected based on signal strength, signal quality, etc. The plurality of communication towers includes an aeronautical band radio configured to communicate data with other aircraft.

[0251] The system can detect obstacles along the flight path based on the received data. The received data can include data from other sources such as local airports of the FAA, other aircraft, etc. The received data can be combined with operator data to reduce the risk of collision or interference with the UAV or a general change in the flight plan. The received data can include current air traffic data, obstacle data, geographical information data, aeronautical voice data, weather data, etc.

[0252] In operation 2615, the system performs grouping of flight paths. Grouping of flight paths includes changing the nose azimuth or speed and adjusting to avoid gaps in image overlap.

[0253] In operation 2620, the system performs image stitching. Successive images are stitched together for a complete understanding of the railway line. Also, image stitching provides an alignment suitable for the analysis theory.

[0254] In operation 2625, the system performs post - processing of images. Image results (including geographical location, time, etc.) are collected from the camera and the GPS receiver. The system can detect defects along the flight path based on the received data. Rolling window logic is used for defects. Rolling window logic compares changes such as pixel color, pixel density, and pixel length between rails in successive or a series of images. The system recognizes that the pixel color and pixel density of the rails are different from those of components from macraggi, ballast, and the surrounding environment (e.g., rock, soil, mud). Also, the system recognizes the distance from common components. For example, the system recognizes the distance between rails and the distance between macraggi. In operation 2630, the system performs report generation. Report generation includes HTML navigation and KML display. The report can be published in any known format including PDF, CSV, etc.

[0255] In operation 2635, the system performs data transfer. The data is stored in the local storage of the UAS and retrieved or downloaded at one of the fixed operator locations or field operator locations.

[0256] FIG. 26 shows an example of a process 2600 for inspecting railway assets using an unmanned aircraft. However, various modifications to FIG. 26 can be made. For example, although depicted herein as a series of steps, the steps of the process can be repeated, occur in parallel, occur in a different order, or occur multiple times.

[0257] Certain embodiments of the present disclosure are based on a UAS capable of vertical takeoff and landing. In particular, the UAS includes an autopilot system that interfaces with a system command and control infrastructure. The UAS also supports various onboard sensors that process navigation information generated from a geographic information system and provide location information. Specifically, these sensors are capable of transmitting and receiving information with an Automatic Dependent Surveillance - Broadcast (ADSB) and a Mode C transponder or their equivalents.

[0258] Embodiments of the UAS have sufficient onboard power generation capabilities to provide reliable power to all of the various aircraft systems such as sensors, communication, and control subsystems. In addition, the UAS preferably has a sufficient liquid fuel capacity to support a flight time of more than 8 hours. The UAS also has a payload capacity necessary to support a plurality of sensors for collecting information and the communication and control subsystems necessary to transmit that information in real - time to a flight operation center. The UAS also preferably includes an onboard information storage medium for local storage of the collected information. In addition, the system includes both onboard and external subsystems to facilitate emergency maneuvering and landing of the UAS in a flight corridor.

[0259] Generally, the onboard sensor takes high-resolution accurate location photos with a resolution of 1 / 4 feet or more from the operating altitude at least twice per second. Preferably, the sensor system also has an independent communication ability to communicate with other onboard subsystems including built-in local computing capabilities, its own navigation system, and autopilot. The sensor may include a photo sensor, a video camera, a thermal detection camera, and / or a multispectral sensor. Specifically, the sensor system includes a real-time day and night video camera for the pilot's situation awareness including at least some limited real-time protection capabilities.

[0260] Also, the system includes software focused on rail detection and analysis of the railway right-of-way condition. Thereby, inspections of linear assets such as tracks, bridges, and the like are advantageously supported. In particular, the system software (both onboard and remote) includes machine vision software trained to understand and recognize critical situations within an area having at least two linear boundary lines. Also, the system software can demonstrate the normal functional state on the linear area.

[0261] More specifically, the onboard software is launched on the UAS in a straight line connecting the sensor and the ground-based communication system. The onboard software processes the data collected by the sensor. Then, the data is loaded into the ground-based communication system. In response, the ground-based communication system outputs quantitative and qualitative data regarding what the sensor captured. The software system processes the large amount of data, creates another set of geographically located data, and then creates a third data set. The system software finally creates several reports associated with the target data and creates a geographic location file that allows the user to easily map the location of the selected state of the target. Preferably, the large amount of data remains unprocessed. The receiver receives only the usable data that is truly needed.

[0262] In addition, the system software also includes field information software. The field information software can be used separately from this system or further used in multiple UASs. The field information software embodies an algorithm for mapping functionality, determines the order in which the software should execute operations, thereby advantageously eliminating human errors. Specifically, the field information software receives media generated by the sensor system, transfers their data to a laptop or other processing system, and then starts the local software. The local software automatically performs data encoding, labeling, and transfer to drives and files, and appropriately sends those data to anyone who needs them (e.g., different departments within an organization). The field information software can be used for any collected data related to the field location. The field information software is preferably based on a network connection system including a server or a set of hardware devices. In some embodiments, the field information software is activated after the flight by the UAS (i.e., performs post-flight data processing). The data can be distributed among network connection resources. The network connection resources perform further analysis and ensure that appropriate encoding and storage of the data are carried out. This helps maintain the management of the distribution process and minimizes data errors.

[0263] Railroad rights-of-way, corridors, and towers are important factors in the aerial railroad inspection system. This system accesses the 900 MHz channel used for the automatic train control system (ATCS) implemented through AAR. However, it is not a strict requirement for the practice of this principle. The hardware and software of this system are optimized to use low-bandwidth AAR channels to increase functionality. In the case of a system using a preferred AAR channel, the user usually requires a license. Redundant Ethernet controls communication with the UAS, including appropriate channels. These functions can be implemented by railroad telecommunications assets.

[0264] The UAS is preferably an aircraft that performs vertical takeoff and landing and operates (including landing) anywhere along the railway asset network. When the UAS takes off, the pilot issues an autopilot command to start the flight. The flight starts following a route programmed by a geographic information system to the actual railway right-of-way, and the UAS flies and then follows that railway right-of-way. In other words, when the pilot activates the autopilot, the system software takes over the operation and flies the UAS as close as possible to the track when it comes over the track. Also, the software system enables the sensor to automatically take pictures of the track twice a second. At the same time, the sensor and the software system control the pitch, yaw, and roll of the UAS. As a result, one or more appropriate sensors can be placed over the track while keeping the track in focus to ensure the required resolution and overlapping images. If the analysis software determines that there was not enough overlap after the flight or if part of the track was missing due to railway right-of-way occupancy, it quickly flies that route again and the sensor takes additional pictures.

[0265] While the autopilot is activated and the sensor is taking pictures, the UAS control system utilizes space-based GPS (ground-based GPS error correction if available) to maintain the UAS over the railway right-of-way while keeping the operating altitude and linear flight path compliance. Both ensure compliance with the regulatory requirements regarding sensor resolution as well as the height and width of the flight path.

[0266] Again in this case, preferably, the UAS and the sensor have independent navigation systems. Advantageously, when both the UAS and the sensor have independent navigation systems, the computing power is conserved for the critical items imposed on each component. For example, the sensor system may include sensor stabilization software and hardware.

[0267] Preferably, the UAS broadcasts its location, speed, altitude, and heading via the existing FAA surveillance network (SBS) and also broadcasts to other aircraft equipped to receive these signals. In addition, the railroad infrastructure can support the augmentation of the FAA SBS system by using auxiliary ADSB / transponder receivers, radars, and other elements along the railroad right-of-way. While the UAS is in flight, its operating status, location, and overall health are transmitted to the pilot via the command and control link. During all phases of flight, the UAS has access to multiple command and control transceiver locations, and a level of command and control redundancy is promised.

[0268] If the UAS loses connection to the command and control system, after a period of time as determined by the operator and / or FAA regulations, the UAS initiates its "link loss profile" and descends automatically to land along the railroad right-of-way. The pilot is aware of the link loss condition and will inform users and dispatchers on the railroad right-of-way about the aircraft's notable landing based on the last transmission from the UAS. Also, secondary communication and navigation systems of the sensors can assist in positioning the UAS.

[0269] In the event of other critical system failures during flight, the UAS automatically initiates one of several pre-established end-of-flight procedures or returns to its launch location or another safe location as programmed. During the course of the flight, the pilot has the option to utilize secondary sensors for real-time imagery of the railroad right-of-way. Also, this secondary sensor can be used for some situation analysis but is mainly used for pilot awareness. During the course of the flight, if a critical situation is identified, the UAS's sensors can utilize a secondary communication channel, which is not the primary connection, to send an immediate notification to the pilot.

[0270] Upon completion of the specified mission, the pilot engages in the landing procedure. The UAS utilizes all of the aforementioned systems to reach the landing site and engages in the landing procedure for vertical landing. The landing procedure includes activating an air-to-ground laser that provides precise landing information to the UAS. During the final stage of the pre-landing flight, the pilot uses the UAS command and control system to ensure a safe landing. The UAS is equipped with multiple support systems to ensure a safe landing. If anything that impedes a safe landing exists on the ground or in the landing area, the landing abort procedure is initiated and an alternative landing site is identified. After a safe landing, the pilot removes the sensor data storage drive and inserts it into the server. The UAS then initiates an automated process of analysis and data distribution, resulting in the delivery of a customized report and a useful dataset.

[0271] The invention has been described with reference to specific embodiments. However, these descriptions are not intended to be construed in a limiting sense. Various modifications of the disclosed embodiments and alternative embodiments of the present disclosure may become apparent to those skilled in the art by reference to the description of the invention. Those skilled in the art should understand that the disclosed concepts and specific embodiments may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Also, those skilled in the art should clearly understand that such equivalent constructs do not depart from the spirit and scope of the present disclosure as set forth in the appended claims.

[0272] Therefore, it is intended that the claims may embrace any such modifications or embodiments that fall within the true scope of the present disclosure.

[0273] The description in this patent document should not be read as implying that a particular element, step, or function is an essential or important element that must be included in the claims. Also, unless the exact term "means for" or "step for" and the participle phrase identifying the subsequent function are explicitly used in a particular claim, none of the claims are intended to invoke 35 U.S.C. § 112(f) with respect to any of the appended claims or claim elements. The use of terms such as "mechanism", "module", "device", "unit", "component", "element", "member", "apparatus", "machine", "system", "processor", "processing device", or "controller" (but not limited thereto) within a claim is understood and intended to refer to structures known to those skilled in the art that are further modified or enhanced by the characteristics of the claim itself and are not intended to invoke 35 U.S.C. § 112(f).

[0274] It may be advantageous to set forth definitions of certain terms and descriptions used throughout this patent document. The terms "comprising" and "including" and their derivatives mean inclusion without limitation. The term "or" is inclusive and means and / or. The description "associated with" and its derivatives may mean including, included, interconnected, encompassing, encompassed, connected to or with, coupled to or with, communicating, cooperating, interposed, juxtaposed, nearest, linked to or with, having, having the characteristics of, having a relationship to or with, or the like. The description "at least one" when used within a list of items means that different combinations of one or more of the listed items may be used or only one of the items in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0275] This disclosure describes certain embodiments and generally related methods. However, variations and substitutions of these embodiments and methods may be apparent to those skilled in the art. Accordingly, the above description of exemplary embodiments does not define nor limit this disclosure. Without departing from the spirit and scope of this disclosure as defined by the following claims, other variations, alternatives, and modifications are also possible.

Claims

1. An air system control network for an unmanned aerial vehicle (UAV) for inspecting railway assets, comprising a plurality of communication towers, a ground control system connected to the plurality of towers, transmitting a flight plan including a railway line and a flight path via the plurality of communication towers, receiving data while the UAV is monitoring the railway line via the plurality of communication towers, detecting an obstacle along the flight path based on the received data, and adjusting the flight plan based on the obstacle a ground control system configured to perform the above An air system control network including.

2. The air system control network according to claim 1, wherein the received data includes current air traffic data, obstacle data, geographical information data, and air voice data.

3. The plurality of communication towers include aviation band radios configured to communicate data with other aircraft, The air system control network according to claim 1, wherein the flight plan is adjusted based on the communicated data.

4. The UAV includes at least one camera configured to capture an image of the railway line, The air system control network according to claim 1, wherein the received data includes a plurality of images captured from the at least one camera mounted on the UAV.

5. The ground control system is monitoring the plurality of images for deviations from the flight plan, and adjusting the flight plan to maintain the railway line in the plurality of images The air system control network according to claim 4, further configured to perform the above.

6. The ground control system is monitoring the plurality of images for a defective state of the railway line The air system control network according to claim 1, further configured to perform the above.

7. The defective state is the difference between a first image and a second image continuously captured along the flight path, and the difference between the first image and a stored image captured at the same location from a previous flight of the UAV The air system control network according to claim 6, identified from the above.

8. An unmanned aerial vehicle (UAV) system for monitoring a railway line, comprising a UAV, and an air system control network The air system control network includes A plurality of communication towers, An on-ground control system connected to the plurality of towers, Transmitting a flight plan including a railway line and a flight route via the plurality of communication towers; Receiving data while the UAV is monitoring the railway line via the plurality of communication towers; Detecting an obstacle along the flight route based on the received data; Adjusting the flight plan based on the obstacle; An on-ground control system configured to perform the above; A unmanned aerial vehicle (UAV) system including the above.

9. The UAV system according to claim 8, wherein the received data includes current air traffic data, obstacle data, geographic information data, and air voice data.

10. The plurality of communication towers include aviation band radios configured to communicate data with other aircraft, The UAV system according to claim 8, wherein the flight plan is adjusted based on the communicated data.

11. The UAV system according to claim 8, wherein the received data includes a plurality of images captured from at least one camera mounted on the UAV.

12. The on-ground control system Monitors the plurality of images for deviations from the flight plan; Adjusts the flight plan to maintain the railway line in the plurality of images; The UAV system according to claim 11, further configured to perform the above.

13. The on-ground control system Monitors the plurality of images for defective conditions of the railway line; The UAV system according to claim 11, further configured to perform the above.

14. The defective condition Is identified from the difference between a first image and a second image continuously captured along the flight route, and The difference between the first image and a stored image captured at the same location from a previous flight of the UAV; The UAV system according to claim 13.

15. A method for an aerial system control network of an unmanned aerial vehicle (UAV) for inspecting railway assets, the method comprising: Transmitting a flight plan including a railway line and a flight route via a plurality of communication towers; Receiving data while the UAV is monitoring the railway line via the plurality of communication towers; Detecting an obstacle along the flight route based on the received data; Adjusting the flight plan based on the obstacle; The method including the above.

16. The method according to claim 15, wherein the received data includes current air traffic data, obstacle data, geographic information data, and aviation voice data.

17. Further comprising communicating data with other aircraft via the airborne radios of the plurality of communication towers, wherein the flight plan is adjusted based on the communicated data, the method according to claim 15.

18. The method according to claim 15, wherein the received data includes a plurality of images captured from at least one camera mounted on the UAV.

19. Further comprising monitoring the plurality of images for deviations from the flight plan, and adjusting the flight plan to maintain the railway line in the plurality of images, the method according to claim 18.

20. Further comprising monitoring the plurality of images for a defective condition of the railway line, wherein the defective condition is determined from a difference between a first image and a second image captured continuously along the flight path, and a difference between the first image and a stored image captured at the same location from a previous flight of the UAV, the method according to claim 18. ​

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