Abstract:
Systems and methods for assisted recovery. An example method receives at least one of a directional or pitch command signal. Localizer or glide slope signals are generated based on the received signal. The localizer or glide slope signals are wirelessly transmitted via a predefined frequency over a transmitter and received at receivers of a navigation system. The vehicle is controlled based on the received signals. A proximity warning device generates an alert when the aircraft is within an alert distance from at least one of terrain, obstacle or special use airspace and an assisted recovery component generates the directional and pitch command signals based on the generated alert and a time delay.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation-in-Part of U.S. patent application Ser. No. 10/782,055, filed Feb. 19, 2004 now U.S. Pat. No. 7,098,810, which is hereby incorporated by reference. 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 60/653,800 filed on Feb. 16, 2005 and is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     When pilot and flight crew become unobservant to ground proximity or other warnings due to attention drawn to handling other situations or emergencies, the pilot and flight crew may fail to react in a timely manner. One solution for resolving situations of this nature includes sending instructions to an auto pilot or flight control system that would provide commands to the flight controls in order to avoid the obstacles. However, there exists no standard interface between warning systems and auto pilots. Thus, it is very expensive to outfit a fleet of aircraft that includes various different types of avionic packages. 
     Therefore, there exists a need to provide a standard and inexpensive interface to allow communication between a warning system and an auto pilot system. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention includes systems and methods for assisted recovery. An example method receives at least one of a directional or pitch command signal. Localizer or glide slope signals are generated based on the received signal. The localizer or glide slope signals are wirelessly transmitted via a predefined frequency over a transmitter and received at receivers of a navigation system. The vehicle is controlled based on the received signals. 
     Upon detection of a “threat” an Assisted Recovery System (ARS) generates signals that are sent to a Wireless Assisted Recovery System (WAR). 
     In one embodiment the WAR generates appropriately modulated RF signals for Localizer and Glide Slope Navigation Receivers (ILS). 
     In another embodiment the WAR generates RF signals that are received and used by other navigation receivers, such as GPS Navigation Receivers. 
     The ILS includes Localizer and Glide Slope systems. 
     In another embodiment, the vehicle is an aircraft, a surface vehicle, or a subsurface vehicle. 
     In still another embodiment, a proximity warning device generates an alert when the aircraft is within an alert distance from at least one of terrain, obstacle or special use airspace and an assisted recovery component generates the directional and pitch command signals based on the generated alert and a time delay. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. 
         FIGS. 1 and 2  are block diagrams of components of the present invention; and 
         FIG. 3  is a flow diagram of an example process performed by the systems shown in  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates example components included within an aircraft  24  for performing the present invention. The aircraft  20  includes a navigation command generation system  24  with a transmit antenna  26 , a navigation system  28  with a receive antenna  30 , and an auto pilot or flight control system  34 . 
     The navigation command generation system  24  generates one or more navigation signals and wirelessly transmits the generated signals to the navigation system  28  via the transmit antenna  26  and the receive antenna  30 . In this example, the auto pilot or flight control system  34  is designed to fly based on navigation signals or instructions generated by the navigation system  28 . The navigation system  28  (e.g. Instrument Landing System (ILS)) generates navigation instructions based on the signals received from the navigation command generation system  24 . Because the navigation system  28  and receive antenna  30  are typically standard on aircraft that include ILS equipment or comparable equipment, the components described above can be inexpensively implemented on these type of aircraft, because the navigation system  28  already includes standardized ILS signal processing components. 
       FIG. 2  illustrates an example embodiment of the system shown in  FIG. 1 . In this example, a system  50  includes the navigation command generation system  24  ( FIG. 1 ) that includes an enhanced ground proximity warning system (EGPWS)  54 , a plurality of sensors  56   a - e , a memory device  58 , a localizer signal generator  62 , and a glide slope signal generator  64 . The EGPWS  54  is in data communication with the sensors  56   a - e , the memory device  58  and the generators  62  and  64 . The memory device  58  includes amongst other things a terrain and obstacle database. The sensors shown in  56   a - e  can be physical sensors located on the aircraft, or the information could be coming from a GPS receiver. The sensor  56   c  in the case of GPS would actually be a ground speed sensor. Likewise heading information from a GPS is computed using track and mag dev/var. In most cases, the EGPWS has the sensors shown and GPS as well. 
     The EGPWS  54  includes hardware and software components for determining the aircraft&#39;s position relative to terrain, obstacles and protected or restricted airspace and for generating alerts based on the determination. The EGPWS  54  also includes an assisted recovery component  60 . The assisted recovery component  60  generates a direction signal and/or altitude signal. The direction signal is a direction that the assisted recovery component  60  desires that the aircraft fly in order to avoid any identified obstruction, such as terrain, man-made obstacle or protected airspace. The altitude signal generated by the assisted recovery component  60  is an altitude value that would allow the aircraft to avoid the identified terrain, obstacle, or airspace. An example assisted recovery component  60  is described in U.S. patent application Ser. No. 10/782,055. 
     The localizer signal generator  62  receives the direction signal from the assisted recovery component  60  and generates a localizer signal that is output through an associated antenna  66  at a previously defined localizer frequency. The glide slope signal generator  64  receives the altitude signal generated by the assisted recovery component  60  and outputs a glide slope signal through an associated antenna  68  according to a previously defined glide slope signal frequency. 
     The system  50  also includes a Navigation System  70  that includes a localizer antenna  72  and a glide slope antenna  74 . The localizer receiver contained within the Navigation System  70  is tuned to receive the signal outputted by the antenna  66 . In one embodiment, the glide slope antenna  74  receives the signal outputted by the antenna  68 . In one embodiment, tuning signals are generated by the assisted recovery component  60  and then sent along a data bus to the Localizer and Glide slope signal generators  62  and  64 , and also to the Navigation System  70 . The navigation system  70 , which consists of one or more Localizer and Glide Slope receivers, tunes these receivers according to the received tuning signals 
     In one embodiment, additional messages are sent via the data bus to force a Flight Management System (FMS) (not shown) to allow tuning of the radios. In another embodiment, the EGPWS  54  communicates with the FMS to force the FMS to tune the radios and engage the autopilot in an approach mode. 
     The navigation system  70  includes a component (not shown) that processes the received localizer and glide slope signals as it would if the signals came from a ground-based system. A display device  76  presents the processed localizer and glide slope signals on a display  76 . An auto pilot or flight control system  78  (hereinafter autopilot) is in data communication with the navigation system  70 . The autopilot  78  is activated or has been previously activated to fly according to the processed localizer and glide slope signals. As such, the autopilot  78  produces flight control signals that are sent to the flight controls  80  for controlling pitch, roll, or yaw or throttle settings of the aircraft in order to maintain course and/or speed relative to the processed localizer and glide slope signals. 
       FIG. 3  illustrates an example process  100  performed by the system  50  shown in  FIG. 2 . First, at a block  102 , flight instructions are received from the assisted recovery component  60 . At a block  104 , localizer or glide slope signals are generated based on the received flight instructions. At a block  106 , the generated localizer or glide slope signals are outputted to the respective transmitters and at a block  110  are received by respective navigation system receivers. At a block  112 , localizer or glide slope values are generated based on the received signals. At a block  114 , the autopilot maintains course or altitude based on the generated localizer or glide slope values. 
     In one example, the assisted recovery component  60  determines that the aircraft is to fly a 6° climb and sends a signal to the glide slope signal generator  64  that is a command or navigation instruction to perform a 6° climb. The glide slope signal generator  64  creates a 6° climb ILS glide slope signal. 
     The assisted recovery component  60  generates a composite signal (a mixture of 90 and 150 Hz.), which is used to amplitude modulate a single transmitter (the generator  64 ), tuned to a Glide Slope frequency. If it is desired to show the autopilot (or pilot) a centered needle, the transmitter is modulated with equal amplitudes of 90 and 150 HZ. If it is desired to make the aircraft climb, the transmitter is modulated to have the 150 Hz portion predominate. In one embodiment, the autopilot is given a signal indicating “fly up” but since moving the aircraft doesn&#39;t change the received signal, the aircraft just continues to climb, trying to center the needle (center the plane on the glideslope). 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, the system described can be fully or partially implemented on vehicles other than aircraft, such as ground-based, sea surface or subsurface vehicles. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.