Abstract:
The invention is related to controlled mechanical platforms for video cameras. A device rotating on a support allows control and stabilization of the position of a camera being rotatable in three dimensions. The construction described above can improve stability of the platform. Vibration level transmitted from the unstable base to the platform is reduced. Areas of application: portable stabilizers for operators, installation of cameras on vehicles, cranes and cables, unmanned machines.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention is a stabilized platform for one or more cameras. 
     This invention relates to platforms for video cameras for rotation in multiple directions at a common intersection point of three rotational axes. 
     With the invention, a position and stability of the mounted video camera(s) can be controlled using a platform having center of mass of a stabilizing part coinciding with rotational axes. 
     Description of the Related Art 
     U.S. patent application Ser. No. 12/669,480 and Chinese patent application No. 20111380351.6 describes mechanisms in which a video camera is located in the center of the rotating unit. 
     Locking elements for axes elements and servo drives are mounted on the sides. 
     The axes elements are fixed to the frames encircling the camera, making said frames quite large. 
     Large frames have disadvantages such as reduced structural rigidity, increased errors in the production and operation, increased loads on bearings. 
     An amplitude of oscillations of the video camera with a telephoto lens can be reduced by reducing frictional forces at the nodes of rotation. 
     This can be achieved by increasing manufacturing accuracy of the axial units and reducing bearings loads. 
       FIG. 4  shows the prior art, where the stabilized platform has a rotating load ( 15 ), a frame ( 16 ), a position of a first bearing ( 17 ), a position of a second bearing ( 18 ), where the direction of gravitational force ( 19 ) is equal to the mass of a rotatable load ( 15 ). 
     In the illustrated prior art, a bearing is being loaded by proportional load ( 20 ), the distance between bearings is L 1  and the distance of the lever arm is L 2 . 
     BRIEF SUMMARY OF THE INVENTION 
     Purpose of the invention is to reduce friction forces of rotational parts between an unstable base and a stable platform and to increase rigidity of the overall construction. 
     The above-mentioned disadvantages are overcome by the use of a compact unit of rotation, locating a video camera at the side and balancing the video camera by a counterweight on an opposite side of the axial unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows front view of an example of the structure for stabilizing a platform. 
         FIG. 2  shows top view of an axial unit. 
         FIG. 3  shows side view of an axial unit. 
         FIG. 4  shows a prior art device. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1-3 , the stabilized platform includes a leg ( 1 ), a housing ( 2 ), and an adjustable platform ( 14 ) supporting and stabilizing a video camera ( 3 ). With reference to  FIGS. 2-3 , the stabilized platform provides a gimbal with three controlled axes of rotation. 
     The stabilized platform further includes an axial unit with: 
     i) a first connector ( 4 ) located on a first axis of rotation ( 4 ) called a panoramic rotation axis ( 4 ) which extends along a length of the leg ( 1 ), 
     ii) two second connectors ( 7 ) located on a second axis of rotation ( 7 ) called a transverse tilting axis ( 7 ), and iii) two third connectors ( 12 ) located on a third axis of rotation ( 12 ) called a longitudinal inclination axis. 
     The first, second, and third axes of rotation intersect at a common intersection point. The second axis of rotation ( 7 ) and the third axis of rotation ( 12 ) are perpendicular one to another 
     As shown in  FIGS. 2-3 , the axial unit further includes a horizontally rotating unit ( 5 ), a servo drive unit ( 6 ,  9 ,  10 ) comprised of a first servo drive ( 6 ), a second servo drive ( 9 ), and a third servo drive ( 10 ). 
     The horizontally rotating unit ( 5 ) is connected to the leg ( 1 ) and rotates around the first axis of rotation ( 4 ). The first connector ( 4 ) connects the horizontally rotating unit ( 5 ) to the leg ( 1 ). The horizontally rotating unit ( 5 ) rotates horizontally, around the first axis of rotation ( 7 ), when the first axis of rotation ( 4 ) extending along a length of the leg ( 1 ) extends vertically. 
     As shown in  FIGS. 2-3 , the axial unit still further includes a transversely tiltable frame ( 8 ), and a longitudinally tiltable frame ( 11 ). 
     The transversely tiltable frame ( 8 ) extends in a direction of the second axis of rotation ( 7 ) and in a direction of the third axis of rotation ( 12 ). The transversely tiltable frame ( 8 ) is tiltable in a transverse plane. 
     As shown in  FIG. 2 , in top view the transversely tiltable frame ( 8 ) is a closed rectangle comprised of four connected sides. 
     The two second connectors ( 7 ) connect two opposite sides of the horizontally rotating unit ( 5 ) to two opposite sides of the transversely tiltable frame ( 8 ) such that the transversely tiltable frame ( 8 ) is rotatable about the second axis of rotation ( 7 ). 
     As shown in  FIG. 3 , in side view the longitudinally tiltable frame ( 11 ) has a U-shape and comprises two arms jointed by a member (the lower member in  FIG. 3  extending along a direction of the transversely tiltable frame ( 8 ). 
     The two arms each have a free end (the upper ends in  FIG. 3 ). The two third connectors ( 12 ) connect inner sides of the arms of the longitudinally tiltable frame ( 11 ) to opposite ends of the transversely tiltable frame ( 8 ) such that the longitudinally tiltable frame ( 11 ) rotates around the third axis of rotation ( 12 ). 
     Outside faces of each of the arms of the longitudinally tiltable frame ( 11 ) include mounting slots ( 13 ) for fastening equipment for stabilization, as shown in  FIG. 2 . The mounting slots ( 13 ) rotate around the third axis of rotation ( 12 ). 
     An adjustable platform ( 14 ), for stabilized equipment, is shown in  FIGS. 2-3  as being mounted to the mounting slots ( 13 ) of the left arm of the longitudinally tiltable frame ( 11 ). 
     The housing ( 2 ) is mounted to the transversely tiltable frame ( 8 ). 
     The axial unit, via the leg ( 1 ), may be supported to an unstable base. The leg ( 1 ) can be directed upwards (as shown in  FIG. 1 ) or downwards and is rotatable about the first axis of rotation ( 4 ). 
     The first servo drive ( 6 ) is mounted on a first side of the horizontally rotating unit ( 5 ). The first connector ( 5 ) connects the leg ( 1 ) to an opposite, second side of the horizontally rotating unit ( 5 ). 
     The second servo drive ( 9 ) is secured on an outside of the transversely tiltable frame ( 8 ), whereas the third servo drive ( 10 ) is secured on an inside of the transversely tiltable frame ( 8 ). 
     The third element ( 12 ) is mounted on the longitudinally tiltable frame ( 11 ). 
     The platform ( 14 ) for stabilized equipment allows to a user to relocate the equipment in three directions to achieve precise balance of a rotating mass. 
     With reference again to  FIG. 1 , the video camera ( 3 ) is mounted on one side of the device. 
     On the opposite side, a position sensor of the stabilized platform, a servo drive controller, and a battery are secured. 
     The servo drive unit is further equipped with internal feedback of the acting force. A mechanical gyroscope may be used to achieve even greater stabilization. 
     Installation of two cameras on opposite sides allows stereoscopic shooting. 
     The above described structure of the stabilized platform for rotation and stabilization of a mounted video camera allows for production of a compact axial unit with increased rigidity and precision. 
     The invention&#39;s stabilized platform allows a center of mass of rotation to be situated between two bearings, thus a load on these two bearings does not exceed a weight of the load. 
     By reducing frictional forces, vibrations of the unstable base transmitted to the stabilized platform are also reduced. 
     Additionally, centers of mass of the stabilized equipment are spaced apart, enhancing the effect of additional inertial stabilization. 
     Areas of application include portable stabilizers for operators, installation of cameras on vehicles, cranes and cables, and unmanned machines.