Abstract:
The present invention provides methods and systems for adjusting video quality outputted by an aerial vehicle to manage the data stream bandwidth to match the needs of each mission segment. A mission segment is monitored in order to determine a preferred video quality of service. A quality of service is set based on the monitored mission segment. The quality of service is selectively altered based on a change of at least one of a mission segment or an environmental condition.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    An unmanned, aerial vehicle (UAV), sometimes called an “unmanned, air-reconnaissance vehicle,” is an unpiloted aircraft. UAVs can be remote controlled or fly autonomously based on pre-programmed flight plans or more complex dynamic automation systems. UAVs are currently used in a number of military roles, including reconnaissance operations. 
         [0002]    The use of any UAV is beneficial only when information can be transmitted back to the operator in real time. As the skies above the battlefield become increasingly cluttered with UAVs, data links can be filled to capacity or overfilled, which results in congestion and poor performance. The flight characteristics of a hovering capable UAV; helicopter configuration, multi open blade, single ducted, or multi ducted has mission segments that require differing levels of quality in terms of image resolution and frame rates. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention provides methods and systems for adjusting video quality outputted by a hovering capable aerial vehicle. The purpose of each mission segment is defined so as to provide a preferred video quality of service. The quality of service changes from imaging needs for controlled flight above obstacles, to imaging needs for controlled flight through obstacles, and image quality for surveillance resolutions. During high speed cruise the image quality is of less interest than the image rate that supports control actions. During hover the image rate is of less importance than the image quality and resolution needed for surveillance. A quality of service is set based on the monitored mission segment and the available radio frequency bandwidth. The quality of service is selectively altered based on a change of at least one of a mission segment or an environmental condition. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings: 
           [0005]      FIG. 1  is a pictorial representation of a Quality of Service (QOS) manager; and 
           [0006]      FIG. 2  illustrates a mission profile with differing segment objectives. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0007]      FIG. 1  illustrates a vehicle/aircraft  202 , such as a hovering UAV, having an example Quality of Service (QOS) manager  212 . The QOS manager  212  monitors mission segment (cruise, transition, hover, etc.) to set a predetermined quality of video to be down linked. Based on the mission segment of the  202 , the QOS manager  212  sets a video quality (frame rate, resolution, etc.) in either real time by an operator or during mission planning to work with the communications link bandwidth limitations. The QOS manager  212  also evaluates the current conditions, such as turbulence, weather and lighting, to adjust for the best video quality. The QOS manager  212 , in one embodiment, adjusts the output of a digital camera. By way of example when the aircraft  202  is operating in forward flight the frame rate may be set to high, such as 30 frames per second, but the image resolution may be set low to 320 px×240 px in order to reduce bandwidth required. The frame rate is set to high to allow for controllability of the flying the aircraft, but the level of detail can be lower because the operator need not see the airspace in high resolution to safely fly the aircraft  202 . Conversely in a hover, when the aircraft  202  is in surveillance mode, the frame rate may be reduced to 5 frames per second, but the resolution increased to 1040 px×960 px. This shows the surveillance target clearly, but does not take up extra bandwidth because of the reduced frame rate. 
         [0008]    The aircraft  202  includes a flight management system (FMS)  204 . The FMS  204  generally includes or is in communication with an inertial navigation system (INS)  206  that communicates heading, velocities, and altitude, a global positioning system (GPS)  208  that communicates position information and a flight management computer (FMC)  210 , that generates guidance information and coupled with the direction, altitude and current position provides flight commands to the FMS  204  in order to fly the aircraft  202 . The FMS  204  is generally programmed for an entire mission prior to the aircraft  202  starting the mission. The FMS  204  contains information such as mission segments, waypoints, direction of travel and altitude. The FMC  210  is also in communication with a QOS manager  212  and sends information including current segment, based on direction of travel, altitude and current position, and conditions. The QOS manager  212  processes the segment information combined with the conditions to determine the frame rate and image size to provide the needed image quality for the mission segment. The QOS manager  212  also receives instructions from a ground controller using a communication device  216 . The QOS manager  212  selectively activates a camera  214  on the aircraft  202 . The aircraft  202  also includes the communication device  216  for transmission of images from the aircraft  202  to an operator. The communications device  216  may communicate with the ground station using digital, analog or any other communication means. In addition to the mission segment management of quality of service the QOS manager  212  may input environmental conditions such as time of day and imager direction relative to light sources, turbulence, and obscurants to enhance image quality, 
         [0009]      FIG. 2  illustrates a mission profile with differing segment objectives for which the QOS manager  212  controls image quality during an example programmed mission  300 . In a first segment  302 , a vehicle  301  is taking off and is in autonomous flight, meaning that it has been given flight instructions taking the vehicle  301  to a preprogrammed altitude. The first segment generally operates in a QOS state 1, which is used for normal flight and is generally a high frame rate and a low resolution. The second segment  304  and the third segment  306 , shows the vehicle  301  traveling to a location, which again places the vehicle  301  in QOS state 1. In the fourth segment  308 , the vehicle  301  is transitioning into an approach and surveillance mode. The fourth segment  308  is operating in QOS State 2, which has a medium frame rate and a medium resolution. The fifth segment  310  has the vehicle  301  in a hover and stare phase. The fifth segment  310  is operating with a lower frame rate and a higher resolution in order to capture the detail of what is happening below. The fifth segment  310  is operating in QOS state 3. The sixth segment  312  shows the vehicle  301  in slow flight surveillance, requiring a frame rate for flying the vehicle  301  but also uses a medium resolution trying to locate a target. In the sixth segment  312  the vehicle  301  is operating in QOS State 2. In the seventh  314 , eighth  316  and ninth  318  segment&#39;s the vehicle  301  is flying back to the operators and is operating in QOS State 1. In alternate embodiments there exist additional alternate QOS States. 
         [0010]    In another embodiment, the QOS manager  212  adjust one or more controllable settings of the camera  214 . For example, an iris setting is adjusted. The iris setting determines the amount of light entering the camera  214 , just like the iris of an eye. Other settings that can be changed on the camera  214  include shutter, aperture, backlight, shutter speed or any other setting that would increase or decrease the size in the recorded information, thereby allowing for more or less resolution. 
         [0011]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.