Miniature pan/tilt tracking mount

• US 5,463,432 A
• Filed: 05/24/1995
• Issued: 10/31/1995
• Est. Priority Date: 05/24/1993
• Status: Expired due to Term

• Current Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: Philip Kahn
• Inventors: Kahn, Philip
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): LEE, EDDIE C H
• Application Number:
  US08/449,257
• Time in Patent Office: 160 Days
• Field of Search: 352/243, 354/81, 354/94, 354/99, 354/293, 358/108
• US Class Current: 352/243
• CPC Class Codes: F16M 11/10 around a horizontal axis F16M11/12 takes precedence
• CPC Class Codes: F16M 11/18 with mechanism for moving the apparatus relatively to the stand
• CPC Class Codes: F16M 11/2014 around a vertical axis F16M11/2035 takes precedence
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G08B 13/1963 Arrangements allowing camera rotation to change view, e.g. pivoting camera, pan-tilt and zoom [PTZ]

Abstract

The invention is directed to a computer-controlled miniature pan/tilt tracking mount for the precise control of position, velocity, and acceleration of small payloads (e.g., a video camera). The invention consists of a motorized rotational tilt axis mounted atop a motorized rotational pan axis. For both axes, a worm gear mounted upon the motor shaft bidirectionally rotates a worm wheel mounted upon the orthogonal load axis shaft. A large ratio of motor size to armature weight provides high relative torque, speed, and accuracy. The worm gears provide compact reduction with minimal backlash and they can hold position without energized motors to conserve power for battery-operated uses. The invention includes integrated motor drive power electronics and microcontroller execution of host computer commands to effect precise control of pan/tilt mount speed, acceleration, position, configuration, and motor and electronics power consumption. Superior motor drive capabilities are achieved by the use of pulse-width modulation (PWM).

Claims

1. A pan/tilt device comprising:

a pan assembly fixed to a support apart from said pan/tilt device, said pan assembly having a pan assembly shaft, said pan assembly shaft being coupled to rotate according to the rotation of a shaft of a pan motor, the rotation of said pan assembly shaft being relative to said support apart from said pan/tilt device, the rotation of said shaft of said pan motor being controlled according to a pan motor input signal;

a tilt assembly fixed to and rotatable with said pan assembly shaft, said tilt assembly having a single continuous tilt assembly shaft, said tilt assembly shaft being coupled to rotate according to the rotation of a shaft of a tilt motor, the rotation of said tilt assembly shaft being relative to said tilt assembly, the rotation of said shaft of said tilt motor being controlled according to a tilt motor input signal, said tilt assembly shaft being perpendicular to said pan assembly shaft; and

a payload mounting plate fixed to and rotatable with said tilt assembly shaft;

wherein said pan assembly includes a pan housing having the pan motor mounted thereto, said pan housing supporting said pan assembly shaft, said pan housing enclosing a set of pan gears coupling said pan assembly shaft to rotate according to the rotation of said shaft of said pan motor, comprising a pan worm gear and a pan worm wheel and a set of pan position detection devices for sensing the position of said pan worm wheel, said pan housing providing protection to said pan worm wheel, said pan worm gear, and said pan position detection devices from environmental contaminants;

wherein the shaft of said pan motor is perpendicular to said pan assembly shaft, wherein said shaft of said pan motor rotates said pan worm gear which is engaged with said pan worm wheel which is fixed to said pan assembly shaft such that rotation of said shaft of said pan motor causes said pan assembly shaft to rotate;

wherein said tilt assembly includes a tilt housing having the tilt motor mounted thereto, said tilt housing supporting said tilt assembly shaft, said tilt housing enclosing a set of tilt gears coupling said tilt assembly shaft to rotate according to the rotation of said shaft of said tilt motor, comprising a tilt worm gear and a tilt worm wheel and a set of tilt position detection devices for sensing the position of said tilt worm wheel, said tilt housing providing protection to said tilt worm wheel, said tilt worm gear, and said tilt position detection devices from environmental contaminants;

wherein shaft of said tilt motor is perpendicular to said tilt assembly shaft, wherein said shaft of said tilt motor rotates said tilt worm gear which is engaged with said tilt worm wheel which is fixed to said tilt assembly shaft such that rotation of said shaft of said tilt motor causes said tilt assembly shaft to rotate; and

wherein said tilt shaft includes a tilt shaft portion that extends outside of said tilt housing, and said payload mounting plate is fixed to said tilt shaft portion.