Abstract:
A turret assembly for attachment on the undersurface of an aircraft that reduces performance limitations due to gimbal lock and reduces the cross section profile of the assembly. The assembly includes a roll actuator including a drive shaft. A yoke having a cross member is coupled to the drive shaft and a pair of prongs. The yoke is rotated via the roll actuator and drive shaft along a roll axis oriented substantially parallel to the body of the aircraft. A turret is mounted on the prongs of the yoke. A tilt actuator is contained within the turret. The tilt actuator tilts the turret on a tilt axis relative to the yoke. The tilt axis is perpendicular to the roll axis.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/220,619, filed Aug. 29, 2011, the entire disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to a moveable ball turret for surveillance aircraft and more specifically to a ball turret having tilt and roll actuation with gimbal lock avoidance. 
       BACKGROUND 
       [0003]    The way that the Vietnam War is now remembered as the helicopter war, the current conflicts in Iraq and Afghanistan may be remembered for the use of unmanned aerial surveillance (UAV) craft or drones. Drones may facilitate remote intelligence gathering, alleviating the need for foot soldiers to enter into hostile areas “blind,” with little or no information about the location and strength of hostile forces. Drones may provide close combat support, such as identifying and eliminating targets of interest, alleviating the need to expose soldiers and/or airmen to potential small arms fire, mortars, rocket grenades, road-side bombs, anti-aircraft weaponry, missiles, and other dangers. 
         [0004]    Although many presently used drones are the roughly the same scale size as piloted aircraft, such aircraft are both relatively expensive and may be detected due to their size. Recently, smaller drones have been developed that may be deployed in greater numbers and are relatively less expensive resulting in greater use by individual units in the field. Smaller drones have certain tradeoffs as they cannot carry the amount of payload of a larger drone. Further, power for such smaller drones is limited due to the size of the aircraft and therefore operating periods are also limited. 
         [0005]    Unmanned drone aircraft typically mount a camera in a ball turret assembly which allows movement in three dimensions to allow the camera to track objects on the ground without altering the flight path of the aircraft. Data such as image data may be captured via a sensor such as a camera and transmitted back to a controller. Known ball turret assemblies use a pan tilt mechanism with a cylindrical or spherical turret to mount a sensor such as a camera. Such devices are suspended from the bottom of the aircraft via a fork shaped yoke that may be rotated around a roll axis via a roll actuator. The tilt motion of such a turret starts from zero degrees pointing the camera straight down to a 90 degree positive or negative tilt pointing the camera in the direction of the flight of the aircraft. Thus, such arrangements traditionally have a roll axis that is vertical and a tilt axis is 90 degrees offset from the roll axis. 
         [0006]    Current turret designs require gimbals and mounting structures that present a relatively large cross-profile. Thus, drag based on the turret mounting for known turret designs is a consideration especially when drag decreases fuel efficiency and decreases operational range. Such increased drag is a significant factor in limiting the range of smaller drones that have limited power supplies. Further, for certain important viewing areas such as the area directly below the aircraft, the gimbal is locked and therefore panning to the right or left is more difficult to access using the traditional actuators because the tilt simply rotates the turret toward the front or rear of the aircraft. Thus panning right or left requires rotating the turret on the roll axis and then tilting the turret. As with all components, fewer moving parts are desirable and this is especially true with smaller drones where the efficiency of the payload needs to be maximized. Ideally, the portion of the coverage affected by gimbal lock should be an area that is less important or not important at all. As explained above, current gimbal designs put gimbal lock either directly below the aircraft, or point them directly forward and therefore gimbal lock effects relatively important viewing areas. 
         [0007]    A further issue is the wiring needed to power and draw data from sensors such as cameras in the ball turret. In known ball turret assemblies, such wiring inhibits the full range of movement of the camera on the ball turret resulting in limited vision. For example, if the turret is rotated to view the area directly below the aircraft, the movement is constrained by the electrical wiring which does not allow the ball to be rotated fully. Since it is desirable for the turret to be rotated fully, conventional mountings substitute a brush interface (a slip ring) for physical wiring which limits the bandwidth thereby limiting data transmission. 
         [0008]    Thus, it would be desirable to have a ball turret mounting system to minimize cross-section and thereby minimize drag. It would also be desirable to have a mounting system for a ball turret that allows efficient actuators for maximum coverage for cameras in the ball turret. Also, it would be desirable to provide a physical wired connection to provide greater data bandwidth. 
       SUMMARY 
       [0009]    According to one example a turret assembly for attachment on the undersurface of an aircraft is disclosed. The assembly includes a roll actuator including a drive shaft. A yoke having a cross member is coupled to the drive shaft and a pair of prongs. The yoke is rotated via the roll actuator and drive shaft along a roll axis oriented substantially parallel to the body of the aircraft. A turret is mounted on the prongs of the yoke. A tilt actuator is located within the turret. The tilt actuator tilts the turret on a tilt axis relative to the yoke. The tilt axis is perpendicular to the roll axis. 
         [0010]    Another example is an aircraft having a fuselage having an undersurface. A control system accepts positioning commands from a ground station. A data control system sends data to the ground station. A roll actuator includes a drive shaft. A yoke has a cross member coupled to the drive shaft and a pair of prongs. The yoke is rotated via the roll actuator and drive shaft along a roll axis oriented substantially parallel to the body of the aircraft. A turret is mounted on the prongs of the yoke. A tilt actuator is located within the turret. The tilt actuator tilts the turret on a tilt axis relative to the yoke. The tilt axis is perpendicular to the roll axis. 
         [0011]    Another example is a method of positioning a turret mounted on the prongs of a yoke having a cross member coupled to a drive shaft and a pair of prongs on the undersurface of an aircraft. The turret is rotated via a roll actuator coupled to the drive shaft along a roll axis oriented substantially parallel to the body of the aircraft. The turret is tilted via a tilt actuator within the turret on a tilt axis relative to the yoke, the tilt axis being perpendicular to the roll axis. 
         [0012]    The above summary of the present invention is not intended to represent each embodiment or every aspect of the present invention. The detailed description and Figures will describe many of the embodiments and aspects of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. 
           [0014]      FIGS. 1A and 1B  is a perspective view of an unmanned surveillance aircraft having an example ball turret assembly; 
           [0015]      FIG. 2A  is close up perspective view of the example ball turret assembly mounted on the aircraft of  FIG. 1 ; 
           [0016]      FIG. 2B  is a bottom view of the example ball turret assembly in  FIG. 2A ; 
           [0017]      FIG. 2C  is a side view of the example ball turret assembly in  FIG. 2A ; 
           [0018]      FIG. 2D  is a front view of the example ball turret assembly in  FIG. 2A ; 
           [0019]      FIG. 2E  is a rear view of the example ball turret assembly in  FIG. 2A ; 
           [0020]      FIGS. 3A-3L  are side and front views of the example ball turret in various tilt and roll positions; 
           [0021]      FIG. 4A  is a cross-section view of the example ball turret of  FIG. 2A  and related components; 
           [0022]      FIG. 4B  is a cross-section top view of the example ball turret of  FIG. 2A  taken along the line  4 B- 4 B′ in  FIG. 4A ; 
           [0023]      FIG. 4C  is a cross-section top view of the example ball turret assembly of  FIG. 2A ; 
           [0024]      FIG. 5  is a block diagram of the electronic and mechanical control systems and data acquisition systems in the ball turret assembly in  FIG. 2 ; 
           [0025]      FIG. 6  is a block diagram of the tilt control system and the data acquisition control system in the ball turret in  FIG. 2 ; 
           [0026]      FIG. 7  is a block diagram of the pan or roll control system in the ball turret mounting in  FIG. 2 ; 
           [0027]      FIG. 8  is a diagram showing the drag parameters of the design of the ball turret in  FIG. 1 ; 
           [0028]      FIG. 9  is a coded diagram of the most frequent used viewing areas for roll and tilt actuation of the ball turret in  FIG. 1 ; and 
           [0029]      FIG. 10  is a view of the example aircraft in  FIGS. 1A-1B  in flight with the areas of gimbal lock of the ball turret. 
       
    
    
       [0030]    While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION 
       [0031]      FIGS. 1A and 1B  are perspective views of an unmanned reconnaissance aircraft  100 . The aircraft  100  has a fuselage  102  mounting a left wing  104  and a right wing  106 . The aircraft  100  is powered by an engine  108  which rotates a propeller  110 . The aircraft  100  is stabilized with the assistance of elevators  114  and a tail  116  mounted on a boom  112 . In this example, the aircraft  100  is small enough to be carried by an individual soldier and has a top speed of about 55 knots and a cruising speed of about 25 knots. Of course, the principles described herein may be applied to larger or smaller aircraft that are faster or slower than the example aircraft  100  in  FIG. 1 . 
         [0032]    The aircraft  100  includes a ball turret assembly  118  that is suspended from an under surface  120  of the fuselage  102 . The ball turret assembly  118  includes a ball turret  122  that is mounted in a housing  124  on the under surface  120 . The ball turret  122  is mounted in front of a fairing  126  that is also part of the housing  124 . In this example, the ball turret  122  holds an infrared camera  130  and a color camera  132 . In this example, the infrared camera  130  may be a MicroTau 320 or 640 model camera available from FLIR and the color camera is a 5 megapixel Model MT9P031 EO sensor. Both cameras are configured for taking approximately 30 frames per second video stream of images but may also send still images at higher resolution. Of course other types of cameras and/or sensors may be mounted in the ball turret  122 . The ball turret  122  is rotated by a yoke which is mounted on the fairing  126 . As will be explained below, the fairing  126  in combination with the ball turret assembly  118  reduces drag because the yoke is behind the ball turret  122 . By actuators for tilting and rolling the ball turret  122 , the cameras  130  and  132  may be directed toward areas under the under surface  120  of the fuselage  102 . As shown in  FIG. 1A , the ball turret has been rotated to point the cameras  130  and  132  to the left side of the aircraft  100 .  FIG. 1A  shows an approximate imaging area that may be viewed by the cameras  130  and  132  in this position.  FIG. 1B  shows the ball turret  122  rotated to position the cameras  130  and  132  to view an area to the front of the aircraft  100 . 
         [0033]      FIGS. 2A-2E  are close up views of the example ball turret assembly  118  in  FIG. 1 .  FIG. 2A  is close up perspective view of the example ball turret assembly  118 ,  FIG. 2B  is a bottom view of the example ball turret assembly  118 ,  FIG. 2C  is a side view of the example ball turret assembly  118 ,  FIG. 2D  is a front view of the example ball turret assembly  118  and  FIG. 2E  is a rear view of the example ball turret assembly  118 . The ball turret assembly  118  includes the ball turret  122  mounted on the fairing  126  on the under surface  120  of  FIG. 1  via a gimbal assembly  200 . A yoke  202  extends from the fairing  126 . The yoke  202  includes a pair of prongs  204  and  206  that hold the ball turret  122  via pins  208  and  210 . The prongs  204  and  206  have respective opposite ends from the pins  208  and  210  connected by a cross bar  212 . The cross bar  212  is attached to a roll drive shaft  214  that supports the yoke  202  from the fairing  126 . The ball turret  122  includes an exterior surface  220  that is water proof and sealed to protect the mechanical and electrical components such as the cameras  130  and  132  stored therein. Since the yoke  202  does not have any actuating or electronic components the number of parts requiring water-proofing is also decreased. The exterior surface  220  has an aperture  222  for the infrared camera  130  and a mounting cylinder  224  for the color camera  132 . 
         [0034]    A roll axis is represented by a dashed line  240  which points forward relative to the aircraft  100 . As will be explained the ball turret  122  may be rotated around the roll axis  240  via the roll drive shaft  214  being rotated by a roll actuator in the fairing  126 . A tilt axis represented by a dashed line  250  is  90  degrees offset from the roll axis  240 . The ball turret  122  is therefore rotated on the prongs  204  and  206  around the tilt axis  250  via a tilt actuator contained in the turret  122 . A wiring harness  260  containing wiring for power, data and communications extends from the fairing  126  to the ball turret  122  through the interior of the drive shaft  214  and is attached to the yoke  202  and follows the prong  204  to the interior of the ball turret  122 . 
         [0035]      FIG. 3A-3L  are side and front views of the example ball turret  122  in various degrees of tilt and roll to position the infrared camera  130  and the color camera  132  relative to the fairing  126  on the under surface  120  of the aircraft  100  in  FIG. 1 .  FIG. 3A  is a side view and  FIG. 3B  is a front view of the ball turret  122  at zero degrees tilt on the tilt axis  250  and zero degrees roll on the roll axis  240 . As shown in  FIGS. 3A-3B , the infra-red camera  130  is pointed directly down to the ground. The yoke  202  is positioned via the actuating the drive shaft  214  via a tilt actuator in the fairing  126  to rotate the prongs  204  and  206  relative to the roll axis  240 . The ball turret  122  is rotated at zero degrees relative to the tilt axis  250  by the tilt actuator within the ball turret  122 . In order to view areas to the immediate right or left of the ball turret  122 , the yoke  202  is rotated via the drive shaft  214  thus avoiding gimbal lock. 
         [0036]      FIG. 3C  is a side view and  FIG. 3D  is a front view of the ball turret  122  at approximately plus seventy degrees tilt and zero degrees roll. In  FIGS. 3C and 3D , the ball turret  122  has been actuated around the tilt axis  250  from the positions shown in  FIGS. 3A and 3B  via the tilt actuator. The rotation around the roll axis  240  remains the same and therefore the cameras  130  and  132  are pointing ahead of the aircraft  100  at a down twenty degree angle from the horizontal plane. 
         [0037]      FIG. 3E  is a side view and  FIG. 3F  is a front view of the ball turret  122  at approximately negative seventy degrees tilt and zero degrees roll. In  FIGS. 3E and 3F , the ball turret  122  has been actuated around the tilt axis  250  from the positions shown in  FIGS. 3A and 3B  via the tilt actuator. The rotation around the roll axis  240  remains the same and therefore the cameras  130  and  132  are pointing behind the aircraft  100  at a down twenty degree angle from the horizontal plane. 
         [0038]      FIG. 3G  is a side view and  FIG. 3H  is a front view of the ball turret  122  at zero degrees tilt and positive ninety degrees roll. In  FIGS. 3G and 3H , the ball turret  122  has been actuated around the roll axis  240  from the positions shown in  FIGS. 3A and 3B  by rotating the drive shaft  214  and thereby the yoke  202 . The rotation around the tilt axis  250  remains the same and therefore the cameras  130  and  132  are pointing to the left side of the aircraft  100 . 
         [0039]      FIG. 3I  is a side view and  FIG. 3J  is a front view of the ball turret  122  at zero degrees tilt and negative ninety degrees roll. In  FIGS. 3I and 3J , the ball turret  122  has been actuated around the roll axis  240  from the positions shown in  FIGS. 3A and 3B  by rotating the drive shaft  214  and thereby the yoke  202 . The rotation around the tilt axis  250  remains the same and therefore the cameras  130  and  132  are pointing to the right side of the aircraft  100 . 
         [0040]      FIG. 3K  is a side view and  FIG. 3L  is a front view of the ball turret  122  at positive twenty degrees tilt and positive one hundred ten degrees roll. In  FIGS. 3K and 3L , the ball turret  122  has been actuated around the roll axis  240  from the positions shown in  FIGS. 3A and 3B  via rotating the drive shaft  214 . The rotation around the tilt axis  250  is at about twenty degrees by rotating the ball turret  122  relative to the yoke  202 . The cameras  130  and  132  are therefore pointing to the left front side of the aircraft  100  at an angle above the plane of the flight path of the aircraft  100 . 
         [0041]      FIGS. 4A and 4B  are cross-section views of the example ball turret  122  and the related ball turret assembly  118  of  FIG. 2 . As shown in  FIGS. 4A -4B , an interior surface  400  of the ball turret  122  encloses various mechanical and electrical components. The infrared camera  130  is mounted on a circuit board  410  while the color camera  132  is mounted on a circuit board  420 . The circuit boards  410  and  420  are fixed on the interior surface  400  in order to orient the infrared camera  130  through the aperture  222  and the color camera  132  through the mounting cylinder  224 . The tilt actuator includes a tilt motor  430  that rotates a drive shaft  432 . The drive shaft  432  drives the gears in a gear box  434 . The gear box  434  down shifts the rotations from the motor  430  to rotate a drive shaft  436  that is mounted on the pin  208  rotatably coupled to the prong  204  of the yoke  202 . The other prong  206  of the yoke  202  is rotatably mounted on the pin  210  on the exterior of the ball turret  122 . 
         [0042]    The yoke  202  is mounted on the drive shaft  214  which is connected to the fairing  126 . The fairing  126  encloses the actuators for the roll or pan motion. The roll actuator thus drives the drive shaft  214  and the yoke  202 . The fairing  126  encloses a pan or roll motor  440  which rotates a drive shaft  442  which drives a gear box  444 . The gear box  444  in turn drives the drive shaft  214  to rotate the yoke  202 .  FIG. 4C  is a top view of the housing  124  which includes the fairing  126  and the ball turret  122 . The fairing  126  encloses a circuit board  450  that holds the electronics for controlling the tilt and roll actuators. A vertical tab  452  includes an electronic connector  454  which provides connections to electronic components contained in the fuselage  102 . A set of cables  456  extend from the connector  454  through an aperture  458  to provide control and data signals to and from the electronic components in the fairing  126  and the ball turret  122 . 
         [0043]    As shown in  FIG. 2B , the wiring harness  260  containing wiring for power, data and communications extends from the fairing  126  to the ball turret  122  through a slip ring assembly and the interior of the drive shaft  214 . As shown in  FIGS. 2B and 2C , the wiring harness  260  is attached to the yoke  202  and follows the prong  204  to the interior of the ball turret  122 . The controls for the roll and tilt actuators prevent the ball turret  122  from rotating the yoke  202  to tangle the wiring harness  260 . Since the data connections are hardwired from sensors such as the cameras  130  and  132 , maximum bandwidth may be achieved from image data acquired by the cameras  130  and  132 . 
         [0044]    This arrangement allows the cameras  130  and  132  in the turret  122  maximum view of the area of interest and reduces the drag of the turret assembly  118 . As explained above, the pan or roll mechanics (actuators) driving the yoke  202  are located behind the ball turret  122  in the fairing  126 . Since the actuators for the roll motion are mounted in the fairing  126  and movement occurs only in the roll actuator in the fairing  126  to rotate the yoke  202  holding the ball turret  122 , the yoke  202  has no moving parts or electronic components. This allows the ball turret  122  and fairing  126  alone to be water proofed to protect the electronic and mechanical components of the ball turret assembly  118  contained in the ball turret  122 . 
         [0045]      FIG. 5  is a block diagram of the electronic and mechanical control systems and data acquisition systems in the ball turret assembly  118  and fuselage  102  of the aircraft  100  in  FIG. 1 . Identical elements are labeled with identical reference numbers as in  FIGS. 1-4 . The control systems include a ball turret control system  500 , an air vehicle control system  502  and a data processing system  504 . As will be explained the control system  502  and data processing system  504  are stored entirely within the fuselage  102  of the aircraft  100  in this example. 
         [0046]    The ball turret control system  500  includes mechanical actuators to roll and tilt the ball turret  122  relative to the aircraft  100  as well as an electronics module  510  to manage the data output from the cameras  130  and  132 . The electronics module  510  is contained within the ball turret  122  and includes the cameras  130  and  132  that are coupled to a video controller  512 . The cameras  130  and  132  output raw image data to a video controller  512 . The video controller  512  in this example is a field programmable gate array (FPGA) configured to process the parallel raw image data from the cameras  130  and  132 . The FPGA is configured to accept the parallel data from the cameras  130  and  132  and serialize it for the video output. The outputs of the video controller  512  are sent to two USB ports  514  and  516 . Of course the data may be routed using other output interfaces. The USB ports  514  and  516  are coupled to the data processing system  504  in the fuselage  102  of the aircraft  100 . 
         [0047]    The ball turret control system  500  includes a tilt control module  520  that controls the tilt motor  430  and a pan or roll control module  522  that controls the roll motor  440 . As explained above, the tilt control module  520  is contained in the turret  122  while the pan or roll control module  522  and roll motor  440  are contained in the fairing  126  in  FIG. 2A . The tilt control module  520  and the roll control module  522  are coupled to a set of angular sensors  524  that sense the position of the turret  122 . In this example, the angular sensors  524  are magnetic sensors that track magnets on the yoke  202  to sense the tilt angular position, and another magnet on the roll drive shaft to sense the roll angular position. A Serial Peripheral Interface (SPI) coupler  526  connects the video controller  512  with the tilt control module  520  to provide data on video display for purpose of orientating an image such as for compensating for rotation and zoom. 
         [0048]    The video data processing system  504  receives serial video data from the USB ports  514  and  516  via a video input controller  530 . The serial video data includes information on how to display each image frame such as rotation and scale. The video data processing system  504  may include an FPGA to convert the raw video data to a data feed to a ground station. The video data processing system  504  may perform stab/tracker according to settings stored by the controller  530 . The video input controller  530  thus receives the input serial video data from the USB ports  514  and  516  and stabilizes the video frame by frame. The video input controller  530  also offsets the video display and smoothes the images from frame to frame to filter out rapid movement. The video data processing system  504  may also perform automatic gain control measurements on the video data and return the results to the ground station. 
         [0049]    The ball turret control system  500  also includes the air vehicle control system  502  which sends control signals via a controller area network (CAN) connector  560  to the tilt control module  520  and the roll control module  522  to position the ball turret  122  relative to the aircraft  100 . The air vehicle control system  502  receives commands from a remote ground controller (not shown). The ground controller may send commands to position the ball turret  122  via a control device such as a joystick. The air vehicle control system  502  forwards the received commands to the tilt control module  520  and the roll control module  522  to rotate the ball turret  122  to the desired position via the tilt and roll motors  430  and  440 . The air vehicle control system  502  also provides sensor and state estimates based on position and speed sensors on the aircraft  100 . The position of the aircraft is passed from the air vehicle control system  502  to the control system  500  via the CAN connector  560  as input data for an algorithm to stabilize and orient the turret  122  to maintain lock on a ground target and therefore compensate for movement of the aircraft  100 . The algorithm runs on a processor  700  in the roll control module  522  as will be explained below. The algorithm converts the aircraft state data such as the aircraft state estimate and body rates into a state estimate internally and then passes commands based on the data to the motor controller software running on cortex processors  600  and  700  (shown in  FIGS. 6 and 7 ) of the respective tilt control module  520  and the roll control module  522  to adjust the tilt and roll of the ball turret  122 . The air vehicle control system  502  also provides mission data such as way points, the flight mode, joystick commands, and camera control data to the turret control system  500  via the CAN connector  560 . The air vehicle control system  502  also interfaces with the video data processing system  504  by sending camera select commands and camera control data for an integrated image. 
         [0050]      FIG. 6  is a block diagram of the ball turret control system  500  which includes various circuit boards and electronic components contained in the ball turret  122  in  FIG. 2 . As explained above, the tilt control module  520  contains inputs and outputs to the infrared camera  130  and the color camera  132 . The tilt control module  520  is also coupled to the tilt motor  430 . 
         [0051]    The control system  500  includes a cortex processor  600 , a tilt motor current sensor  602 , a tilt angular sensor  604 , a bridge  606 , a CAN receiver/transmitter  608  and a power regulator  610 . The cortex processor  600  controls the motor  430  via the bridge  606  in response to commands received on the CAN receiver/transmitter  608 . The cortex processor  600  obtains motor rotation data from the motor sensor  602  and the angular sensor  604  and sends the data to the CAN receiver/transmitter  608 . The angular sensor  604  is an angular or proximate Hall effect sensor in this example that senses the magnetic field of a magnet on yoke  202  to determine the angular position of the ball turret  122 . A series of connectors including a motor control connector  630 , a CAN connector  632 , a pair of USB connectors  634  and  636  and a power connector  638  are bundled in the wiring harness  260  to connect the control system  500  to the components in the fairing  126 . 
         [0052]    The power regulator  610  receives power from the power connector  638  which is coupled to a power supply such as batteries carried by the aircraft  100 . The power regulator  610  provides power to the electrical components at different voltages specific to the electronic component. 
         [0053]      FIG. 7  is a block diagram of the roll control system  522  in the ball turret assembly  118  in  FIG. 2 . The roll control system  522  includes a cortex processor  700 , a roll motor current sensor  702 , a roll angular sensor  704 , a bridge  706 , a CAN receiver/transmitter  708 , a second CAN receiver transmitter  710 , a tilt system interface  712 , a power regulator  714 , and a control system interface  716 . The cortex processor  700  controls the roll or pan motor  440  with motor control input  718  to the bridge  706  in response to commands received on the CAN receiver/transmitter  710 . The cortex processor  700  relays tilt commands via the CAN receiver/transmitter  708  via the tilt interface  712  to the tilt control module  520 . The cortex processor  700  obtains motor rotation data from the motor sensor  702  and the angular sensor  704  and sends the data to the CAN receiver/transmitter  708  which sends the data to the air vehicle control system  502  in  FIG. 5 . The angular sensor  704  is an angular or proximate Hall effect sensor in this example that senses the magnetic field of a magnet mounted on the yoke  202  to determine the roll angular position of the ball turret  122 . 
         [0054]    The power regulator  714  receives power from a power input  720  which is coupled to a power supply such as batteries carried by the aircraft  100 . The power regulator  714  provides power to the electrical components at different voltages specific to the electronic component. 
         [0055]    With the present configuration of the ball turret  122 , solid wire connections may be used such as the wiring harness  260  between the roll actuator controls and the electronic controls in the ball turret  122  since the turret  122  is mounted in front of the fairing  126  thereby eliminating a slip ring or brush configuration. Because of this mounting and the natural constraints of the body of the aircraft  100 , the pan and tilt movements do not twist the wiring harness when the cameras  130  and  132  are pointed down to the ground and moved to the left or right. Such a configuration also avoids gimbal lock when positioning the cameras  130  and  132  straight below the aircraft for applications such as mapping. The fairing  126  in conjunction with the housing  124  surround the ball turret  122  and function as smooth surfaces with reduced cross section to reduce drag. 
         [0056]      FIG. 8  is a series of drag profiles at different speeds of the aircraft  100  with various cross-sections measured in drag area. The horizontal axis represents the drag area of the ball turret assembly  118  while the vertical axis represents the endurance of the aircraft  100 . A solid line  800  represents drag at sea level at cruise speed. A solid line  802  represents drag at an altitude of 12,500 feet at cruise speed. A dashed line  804  represents drag at maximum air speed at sea level. A dashed line  806  represents drag at maximum air speed at 12,500 feet altitude. 
         [0057]    As shown in  FIG. 8 , the endurance of the aircraft is affected by the cross section area of the ball turret assembly  118  which creates drag. The larger the cross section area of the ball turret assembly  118 , the shorter the endurance of the aircraft. An arrow  810  represents the cross section area of the mounting of the ball turret assembly  118  in  FIGS. 2-4 . As may be shown, the ball turret  122  in conjunction with the fairing  126  reduces the forward profile of the ball turret  122  and decreases drag. As explained above, the pan or roll mechanics (actuators) are contained in the fairing  126  and behind the ball turret  122  thereby reducing the drag from such components. 
         [0058]      FIG. 9  is a graphic showing the desired areas of the positioning of the ball turret  122  relative to the cameras  130  and  132 . A vertical axis  900  represents the elevation which is controlled by a combination of the roll and tilt of the ball turret  122 . The elevation is limited by the fuselage  102  of the aircraft  100  and therefore ranges from negative 90 degrees (straight down) to positive 20 degrees. A horizontal axis  902  represents the azimuth which ranges from negative 180 degrees to positive 180 degrees. A set of areas  904  represents the general position of the cameras  130  and  132  for functions such as surveillance and reconnaissance. A set of other areas  906  represents areas that are blocked by the aircraft  100 . A set of areas  908  represent other areas that may be potential positions for the cameras  130  and  132  during a variety of missions. A set of areas  910  represents the general position of the cameras  130  and  132  for functions such as mapping. In previous systems, this is the set of areas most affected by limited performance due to gimbal lock. A final set of areas  912  represents a region of lower or minimal observation interest (namely, an area above the horizon and generally ahead of the air vehicle). Within the areas  912  can lie an area or region (such as area  1006 , described below in  FIG. 10 ), where the performance of the turret  122  is limited and/or effected by the turret&#39;s gimbal lock. As such, this area  912  is not of typical use or importance to any anticipated gimbal operations and functions. That is, by aligning the roll-axis to be directed above the horizon and in front of the aircraft  100  during its typical operations, the region or area of gimbal lock is placed such that it will have minimum to no effect on the typical operation of the ball-turret  122 . 
         [0059]      FIG. 10  is a view of the example aircraft  100  in  FIGS. 1A-1B  in flight with the areas of gimbal lock of the ball turret  122  such as those shown in the areas  912  of the graphic in  FIG. 9 . The aircraft  100  is shown in flight relative to a line  1000  representing the horizon. As shown in  FIG. 10 , the aircraft  100  is generally flown at an angle relative to the horizon  1000  (that is, the aircraft while flying may have a positive angle of attack relative to a horizontal, or substantially horizontal, direction of travel). The turret  122  is generally pointed at areas on the ground such as an area  1002  which avoid gimbal lock. The turret  122  may be pointed to an area  1004  that is straight ahead of the flight of the aircraft  1000  and avoid gimbal lock due to the angle of the aircraft  100  relative to the horizon  1000 . As may be seen in  FIG. 10 , when pointed at the area  1004 , the ball turret  122  is actually tilted relative to the center axis of aircraft  100 . The ball turret  122  is in gimbal lock in a position  1006  above the horizon  1000  that is aligned with a dashed line  1008  representing the tilt axis of the turret  122 . The area  1006  is above the horizon  1000  and therefore is not generally used (as the vehicle is typically used to view and track ground based objects) thereby avoiding gimbal lock. This positioning of the roll-axis also provides the benefit of allowing a roll-axis control motor or actuator to be positioned in the fairing positioned directly behind the ball-turret  122  (such as the fairing  126  shown in  FIGS. 1-4  and referenced herein above). 
         [0060]    The various controllers such as the video controller  512  in  FIG. 5 , and the cortex processors  600  and  700  in  FIGS. 6 and 7  may be conveniently implemented using one or more general purpose computer systems, microprocessors, digital signal processors, micro-controllers, application specific integrated circuits (ASIC), programmable logic devices (PLD), field programmable logic devices (FPLD), field programmable gate arrays (FPGA) and the like, programmed according to the teachings as described and illustrated herein, as will be appreciated by those skilled in the computer, software and networking arts. 
         [0061]    While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.