Patent Publication Number: US-2020302794-A1

Title: Monitor and control of surface traffic at airport

Description:
BACKGROUND 
     This Application is a non-provisional U.S. Patent Application claiming priority to, and benefit of Indian Provisional Patent Application No. 201641026764, entitled “MONITOR AND CONTROL OF SURFACE TRAFFIC AT AIRPORT” and filed on Aug. 5, 2016, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     Many different types of vehicles travel on the surface at airports. These vehicles include aircraft as well as trucks, cars, busses and other vehicles. As these vehicles move around, there are many opportunities for accidents to occur due to the size differences of the vehicles, weather conditions, and the ever increasing volume of such traffic as the accessibility of air travel continues to expand. 
     Existing systems for managing surface traffic at airports have various short comings. For example, existing systems typically are centered on providing situational awareness and data to pilots of aircraft. The other surface vehicles such as baggage trucks, busses, and other support vehicles are not monitored and their position is not reported to the larger aircraft. Further, these other surface vehicles do not have access to the data on the location and trajectory of the larger aircraft. 
     Therefore, what is needed in the art are systems and methods for monitoring and controlling the location and activity of surface vehicles, including non-aircraft, to assist the operators of such vehicles to avoid accidents. 
     SUMMARY 
     A surface movement, guidance and control system is provided. The system includes a plurality of base stations, disposed at a site, each base station providing a coverage area and having a known geo location and using an IP-based high data rate radio link with low latency. Each base station is adapted to receive periodic positional updates from vehicles on the site over the IP-based high data rate radio link. The system also includes a server. The server is communicatively coupled to the plurality of base stations. The server is configured to track and periodically transmit the location of the vehicles to the base stations. Each base station broadcasts vehicle position information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a system for monitoring and controlling surface vehicles and aircraft at an airport according to an embodiment. 
         FIG. 2  is a block diagram of a system for monitoring and controlling surface vehicles and aircraft at an airport according to another embodiment. 
         FIG. 3  is a flow chart of a process for monitoring and controlling surface vehicles and aircraft according to an embodiment. 
         FIG. 4  is a block diagram of a control center for monitoring and controlling surface vehicles and aircraft according to an embodiment. 
         FIG. 5  is a diagram of a customer premises equipment for use in a surface vehicle and aircraft according to an embodiment. 
         FIG. 6  is a block diagram of a software architecture for customer premises equipment for surface vehicles and aircraft according to an embodiment. 
         FIG. 7  is a diagram of traffic display software for a central server of  FIG. 4 . 
         FIG. 8  is a block diagram of a system for monitoring and controlling surface vehicles and aircraft according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     With the increase in air traffic, and thus the increase in tarmac congestion, at some airports, it has become desirable that these airports include a traffic-monitoring system that monitors and displays, in real time, the respective positions of all mobile stations (e.g., aircraft, baggage carts, emergency vehicles), and that helps airport operators to prevent collisions or other problems resulting from improper positioning or movement of mobile stations. One such system for which engineers are currently developing standards is an Aeronautical Mobile Airport Communications System (AeroMACS). Airport engineers envision that with an AeroMACS, a mobile station will determine, periodically, its position and report it to one or more servers via one or more base stations that are strategically placed in and around the airport so that wherever a mobile station is located within or around the airport, it will be within communication range of at least one base station. Engineers also envision that an AeroMACS will have other capabilities in addition to traffic monitoring. For example, engineers envision that an AeroMACS will allow a mobile station to report its status (e.g., fuel level, gate assignment, whether any components are malfunctioning) to one or more servers, and to receive instructions (e.g., to leave the gate, to hold its current position until further notice) and other information from the one or more servers. 
       FIG. 1  is a diagram of a system  10 , which includes a plurality of base stations (BS)  12  that are positioned at various locations around a site, such as an airport, to monitor and control the movement of vehicles at the site. The base stations  12  each have a coverage area  20  and are communicatively coupled to a control center (CC)  14 , e.g., via a Local Area Network (LAN) or other appropriate back-haul technology at the site. Together, base stations  12  and control center  14  form a system that enables monitoring, tracking and controlling of a number of mobile stations (MS)  16  (e.g., aircraft, baggage carts, emergency vehicles, etc.), and which can solve some or all of the above-described problems with existing systems for tracking ground movement at a site such as an airport according to an embodiment. 
     These base stations  12 , in one embodiment, provide an IP-based high data rate radio link according to a standard such as AeroMACS. Advantageously, the AeroMACS standard provides a high bandwidth communication link on the order of 5 to 10 Mbps along with low latency on the order of 10 ms. Additionally, the AeroMACS standard provides a priority and preemption capability that gives preference to certain messages, users or uses, e.g., messages related to safety of the vehicles traveling on the surface of the site. By incorporating this priority, the AeorMACS bandwidth can be used for other less critical applications, e.g., Voice over IP, without jeopardizing the safety of the vehicles managed by the system  10  by ensuring that the critical position information and conflict alerts can be exchanged without affecting system performance. 
     The base stations  12  are configured to allow communications between the control center  14  and the mobile stations  16  much like cell towers are configured to allow communications between mobile phones and a cell base station. For example, the control center  14  can be configured to send instructions (e.g., halt, proceed, return to a home position, etc.) to a mobile station  16  via the base station  12  that is wirelessly connected to the mobile station, and a mobile station  16  can be configured to send its current position, its status (e.g., in service, out of service, waiting for an instruction to proceed, instructed task complete, etc.), or an acknowledgement (e.g., instruction received) to the control center  14  via the base station  12  that is wirelessly coupled to the mobile station  16 . Periodically, the control center  14  broadcasts the current position of some or all of the vehicles over some or all of the base stations  12  so that each vehicle that receives the message will know, e.g., the position and trajectory of the vehicles in its vicinity. 
     The base stations  12  can be configured to determine which base station should be connected to a particular mobile station, even as the mobile station is moving, in much the same way as cell towers determines which cell tower should be connected to a mobile phone even while the mobile phone is moving. The control center  14  and base stations  12  are in fixed positions, such that they may communicate with one another over a wired channel or a wireless channel in a wired, wireless or combination of wireless and wired local area network. 
     It is contemplated that a system provider will provide the base stations  12  and the control center  14 , and the relative software and firmware for the server and base stations. In other embodiments, the system provider also can provide some or all of the mobile stations  16  and the software and firmware for the mobile stations. Moreover, although described for instantiation in an airport, the system  10  can be instantiated in or on a site (e.g., a warehouse, a military base, an offshore oil rig, etc.) other than an airport to monitor and control the operation of vehicles at the site. 
       FIG. 2  is a block diagram of another embodiment of a system, indicated generally at  200 , for monitoring and controlling vehicles, e.g., surface vehicles and aircraft (collectively “mobile stations”  206 ) at a site such as an airport according to another embodiment. System  200  includes a plurality of base stations (BS)  202  that are positioned at various locations around the site such as an airport. These base stations  202 , in one embodiment, provide an IP-based high data rate radio link according to a standard such as AeroMACS with the same advantages discussed above with respect to base stations  12  of  FIG. 1 . The base stations  202  are coupled to a control center  204  over the local area network (LAN)  205  of system  200 . Control center  204  includes a database  208  that tracks the current location of each of the mobile stations that are in communication with system  200  via base stations  202 . In some embodiments, the location database  208  stores other pieces of information regarding mobile stations  206 , e.g., current trajectory, destination, fuel level, etc. 
     In one embodiment, the base stations  202  can be used to assist mobile stations  206  to precisely determine the location of the mobile station  206 . To this end, the precise location of each base station  202  is surveyed and determined at the time system  200  is set up. Then, in operation, base station  202  uses a Global Positioning System (GPS) receiver  212  to determine its location. Base station  202  compares the output of the GPS receiver  212  to the known location and determines a correction factor. This correction factor is shared with the mobile stations  206  to improve their determination of their own location. Thus, the mobile stations  206  are able to determine their physical location to within a meter using GPS. 
     The operation of the system of  FIG. 2  is described in conjunction with  FIG. 3 .  FIG. 3  is a flow chart of a process for monitoring and controlling vehicles, e.g., surface vehicles and aircraft on the ground at an airport, according to an embodiment. The process begins at block  302 . The mobile stations  206  transmit their current location and other information on a wireless communication link between the mobile station  206  and the base station  202  to which the mobile station  206  is connected. The mobile stations  206  transmit this information on a periodic basis, e.g., once per second. In one embodiment, the packet size for the information is approximately 50 bytes. With this refresh rate and packet size, a 10 Mbps AeroMACS channel can track thousands of vehicles even assuming overhead on the data link of 20 percent. 
     At block  304 , this information is relayed by each of the base stations  202  to the control center  204  so that the information from the mobile stations can be consolidated at block  306 . The control center  204  includes a database  208  that is used to track the data from the individual mobile stations  206 . Periodically, the control center  204  shares information from database  208  with one or more of the mobile stations  206 . For example, control center  204  generates a broadcast, multicast or point-to-point message at block  308 . This message includes information from database  208  on the various vehicles being tracked by system  200 . In one embodiment, the process broadcasts the location of all mobile stations  206  to all of the mobile stations  206 . In this embodiment, the broadcast message is transmitted to the base stations  202  at block  310  and broadcasted to the mobile stations at block  312 . In other embodiments, position information is sent to one or more mobile stations in either a point-to-point message (via a connected base station) or in a multicast message to selected mobile stations. 
     In some embodiments, filtering is used on the data that is transmitted to all, some or as few as one of the mobile stations  206 . For example, the data transmitted to a particular mobile station may be limited to the location of other mobile stations connected to the same base station  202  as the mobile station in a point-to-point message. Further, in other examples, the data transmitted to a mobile station  206  may be limited to potential hazards and vehicles on the current path of the mobile station  206 . For aircraft, the mobile station  206  may only receive information on vehicles on its projected taxiway. 
       FIG. 4  is a block diagram of a control center  400  for monitoring and controlling vehicles, e.g., surface vehicles and aircraft at an airport, according to an embodiment. The control center includes a central server  402  that is coupled to a display  404 . Central server  402  includes a processor  406  and memory  408  that are interconnected over a bus  409 . Program instructions are stored on memory  408  to implement a protocol for monitoring and controlling vehicles, e.g., mobile stations  206  of  FIG. 2 , using a process such as the process of  FIG. 3 . The program instructions in memory  408  are executed on processor  406 . Additionally, as processor  406  receives information from mobile devices  206 , processor  406  stores the information in memory  408 , for example, in a location database such as location database  208  of  FIG. 2 . Processor  406  also accesses the data in the location database in memory  408  to generate one or more multicast or broadcast messages to send to mobile devices  206 . 
     Central server  402  also includes network interface  412 . The network interface  412 , in one embodiment, includes an Ethernet port for connecting to a Local Area Network (LAN) for the airport. In other embodiments, the network interface  412  comprises a wireless interface, e.g., an AeroMACS or other appropriate high data rate link. The multicast messages from the processor  406  are transmitted out of the network interface  412  to the base stations  202  for transmission to the mobile stations  206 . 
     Central server  402  also displays vehicle positions on display  404 . Processor  406  generates a graphical map  414  of the site, e.g., the airport, warehouse, military base, oil rig or other site, on a real-time basis, e.g., with a refresh rate of approximately  1  second. The processor  406  superimposes the current position and information about the mobile stations  206  located on the selected portion of the map. The user may zoom in or out to change the portion of the map  414  of the airport area that is displayed on the display  404 . Further, the user can pan from side to side and up and down on the map  414 . 
     Central server  402  also Includes I/O ports  410  to allow attachment of human machine interface such as keyboard, mouse and joystick to allow the user to manipulate the image presented on the display  404 . In some embodiments, the input/output interface includes other components that allow the user to communicate directly with the vehicle. For example, the central server  402  may be coupled to equipment at input/output ports  410  that enable the user to provide voice or textual communication with the driver or passenger of the mobile station  206 . Alternatively, input/output port  410  may be coupled to equipment that is used to remotely control a mobile station, e.g., a joy stick or other device to control the speed or direction of movement of the mobile station  206 . 
       FIG. 5  is a diagram of a customer premises equipment (CPE)  500  for use in a vehicle, such as a surface vehicle and aircraft, according to an embodiment. CPE  500  operates to determine the position of an associated surface vehicle, e.g., aircraft, baggage car, emergency vehicle, etc. Processor  502  runs software stored in memory  504  to implement the various functions of CPE  500 . For example, processor  502  runs software for determining the position of CPE  500  based on information from GPS module  506 . Further, processor  500  transmits the position and other information about CPE  500  and its associate vehicle via IP-based modem (e.g., AeroMACS modem)  510 . 
     In some embodiments, CPE  500  also includes additional communication functions. For example, CPE  500  may include WiFi functionality in WiFi modem  508  to communicate with optional tablet  514 . Tablet  514  includes display  516  that displays a map similar to display  404  of central server  402 . Processor  502  uses the data broadcast from the central server  402  to update a database in memory  504  with the location and other information about vehicles on the airport and displays the information on a map, like shown and described above with respect to  FIG. 4 . Additionally, CPE  500  may also include an Ethernet port  512  to allow CPE to be plugged into a wired network for software updates, to share position information, etc. 
       FIG. 6  is a block diagram of a software architecture for customer premises equipment  500  of  FIG. 5  for use in vehicles, such as surface vehicles and aircraft, according to an embodiment. The software architecture is built on IP-based modem software (SW)  600 , e.g., AeroMACS software. In one embodiment, software  600  runs on processor  502  of CPE  500 . Software  600 , in one embodiment, is software for implementing a modem that is compliant with the AeroMACS standard. Software  600  includes a socket API  602  that interfaces with D-GPS software  604  and position out software  606 . D-GPS software  604  joins a multicast group to receive position updates for vehicles that are tracked by, for example, control center  204  of  FIG. 2 . 
     Further, D-GPS software  604  also functions to determine the location of CPE  500 . To that end, D-GPS software  604  receives GPS offsets from a base station, e.g., base station  202  of  FIG. 2 . As discussed above, these offsets are generated by comparing the output of a local GPS receiver  212  at the base station  202  with a known position of the base station. Further, the D-GPS software  604  provides the updated offsets to position out software  606 . 
     Position out software  606  reads the GPS position information and applies the offsets from D-GPS software  604 . Position out software  606  also formats information about the CPE  500  similar to the format used in Automatic Dependent Surveillance-Broadcast (ADS-B) messages. Position out software  606  sends the information to the multicast address associated with the control center  204  to report the current status of the CPE  500 . 
       FIG. 7  is a diagram of traffic display software  700  for the central server  402  of  FIG. 4  or CPE  500  of  FIG. 5 . Socket layer  702  provides an interface between the operating system and position in software  704  running on processor  406  or processor  502 . Socket layer  702  communicates information on vehicles, e.g., position and trajectory, etc. to position in software  704 . 
     Position in software  704  receives the information via the IP-based modem  510  in CPE  500 . The position in software  704  passes the information to, for example, the tablet (Cockpit Display of Trafficlnformation (CDTI)  514  for display on screen  516 . In a similar manner, software  700  can be used to display the position information on map  414  on display  404 . 
       FIG. 8  is a block diagram of a system  800  for monitoring and controlling vehicles, such as surface vehicles and aircraft, according to another embodiment. This embodiment is similar to the embodiment of  FIG. 2 . However, in this embodiment, the central server  204  includes a bridge  850 . Bridge  850  enables system  800  to receive position data from mobile stations  206  via both base stations  202  and from Mode-S transponders  852  via ADS-B receivers  854 . In other embodiments, bridge  850  is configured to communication with other sensors such as Universal Access Transceiver (UAT) transmitters, radar and or other airport-based sensors such as multilateration sensors. Bridge  850  receives data from Mode-S or UAT transponders  852  regarding the position, trajectory, etc. of an associated aircraft. This information is merged with the data from mobile stations  206  and incorporated in broadcast messages from the base stations  202  to mobile stations  206 . The information from the Mode-S or UAT transponders is also included in the data presented on the display, e.g., map  414  of display  404  in control center  404  of  FIG. 4 . For Mobile stations equipped with both AeroMACS and UAT or Mode-S transponders, the Central Server can compare position reports received via UAT or Mode-S against position data received over AeroMACS and generate alerts on the display when any anomaly is detected. 
     EXAMPLE EMBODIMENTS 
     Example 1 includes a surface movement, guidance and control system, comprising: a plurality of base stations, disposed at a site, each base station providing a coverage area and having a known geo location and using an IP-based high data rate radio link; wherein each base station is adapted to receive periodic positional updates from vehicles on the site over the IP-based high data rate radio link; and a server, communicatively coupled to the plurality of base stations, the server is configured to track and periodically transmit the location of the vehicles to the base stations; and wherein each base station broadcasts vehicle position information. 
     Example 2 includes the system of Example of 1, wherein the server is communicatively coupled to the plurality of base stations over a local area network, and wherein the base station comprises an AeroMACS base station. 
     Example 3 includes the system of example 2, wherein the local area network comprise a wired network, a wireless network or a combination of wired and wireless network connections. 
     Example 4 includes the system of any of examples 1-3, wherein the site is an airport and wherein the server is configured to track and periodically transmit the location of aircraft and surface vehicles. 
     Example 5 includes the system of example 4, wherein the server is located in a control center and the control center further includes a display coupled to the server to display, on a real-time basis, the location of the aircraft and surface vehicles. 
     Example 6 includes the system of example 5, wherein the server further includes a location database for storing the current location of the aircraft and surface vehicles. 
     Example 7. The system of any of examples 1-6, wherein each base station includes a global positioning system (GPS) receiver that the base station uses to produce and provide correction factors to the aircraft and surface vehicles to improve the accuracy of the position determinations of the vehicles. 
     Example 8 includes the system of any of examples 1-7, wherein the server further includes a bridge that communicates with the plurality of base stations and with a plurality of transponders, each transponder is associated with a vehicle to provide at least position information to the server. 
     Example 9 includes a method for providing surface guidance movement and control, the method comprising: receiving updates from a plurality of surface vehicles and aircraft at an IP-based radio link of a plurality of AeroMACS base stations; forwarding the updates from each of the plurality of AeroMACS base stations to a central server; updating a database with the updates from the plurality of surface vehicles and aircraft at the central server; generating a message containing information from the database; transmitting the message to at least one of the plurality of AeroMACS base stations; broadcasting the message from the at least one of the plurality of AeroMACS base stations. 
     Example 10 includes the method of example 9, wherein broadcasting the message comprises broadcasting the messsage from each of the plurality of AeroMACS base stations. 
     Example 11 includes the method of any of examples 9-10, wherein broadcasting the message comprises broadcasting the message as a multicast message from at least one of the AeroMACS base stations. 
     Example 12 includes the method of any of examples 9-11, wherein broadcasting the message comprises broadcasting the message as a point-to-point message from one of the plurality of base stations. 
     Example 13 includes the method of any of examples 9-12, wherein generating a message comprises filtering the information from the database to select information that is placed in a message to a mobile station. 
     Example 14 include the method of any of examples 9-13, wherein receiving updates comprises receiving updates as to at least one of position, trajectory, destination, and fuel level of one or more of the plurality of surface vehicles and aircraft. 
     Example 15 includes the method of any of examples 9-13, wherein generating a message comprises generating a message containing the current location of the plurality of surface vehicles and aircraft. 
     Example 16 includes a customer premises equipment (CPE) associated with a vehicle, the CPE comprising: a GPS module, configured to provide data relative to the position of the CPE; an IP-based modem, configured for communicating with an IP-based base station; a memory configured to store a database that includes the current location of a plurality vehicles; a processor for executing program instructions stored on a non-transitory storage medium to cause the processor to: determine the location of the CPE based on the data from the GPS module; and transmit the determined location to a central server using the IP-based modem. 
     Example 17 includes the CPE of example 16, wherein the IP-based modem receives the current location of the plurality of vehicles from the central server via the IP-based base station. 
     Example 18 includes the CPE of any of examples 16-17, wherein the memory is configured to store additional information in the database including trajectory, destination, and fuel level of one or more of the plurality of vehicles. 
     Example 19 includes the CPE of any of examples 16-18, wherein the program instructions further cause the processor to read position information from the GPS module and apply offsets received from the IP-based base station through the IP-based modem to the read position information. 
     Example 20 includes the CPE any of examples  16 - 19 , and further including an interface for communicating with a tablet for displaying information from the database. 
     A number of embodiments of the invention defined by the following claims have been described. Nevertheless, it will be understood that various modifications to the described embodiments may be made without departing from the spirit and scope of the claimed invention. Accordingly, other embodiments are within the scope of the following claims.