Stabilized platform system for camera

• US 5,897,223 A
• Filed: 11/17/1997
• Issued: 04/27/1999
• Est. Priority Date: 11/17/1997
• Status: Expired due to Term

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Wescam, Inc. (L3Harris Technologies, Inc.)
• Inventors: Alas, Raigo, Tritchew, Steven, Lewis, Michael D.
• Primary Examiner(s): Blankenship, Howard B.
• Application Number:
  US08/971,617
• Time in Patent Office: 526 Days
• Field of Search: 396/7, 396/12, 396/13, 396/419, 396/428, 348/144-147
• US Class Current: 396/13
• CPC Class Codes: G02B 27/644 compensating for large deviations, e.g. maintaining a fixed line of sight while a vehicle on which the system is mounted changes course
• CPC Class Codes: G03B 15/006 Apparatus mounted on flying objects

Abstract

A stabilized platform system for isolating a payload from angular motion and translational and angular vibration of a supporting structure, has an inner gimbal for carrying the payload, a sprung shell containing and carrying the inner gimbal in a manner permitting the inner gimbal a limited amount of angular movement relative thereto about pitch, roll and yaw axes, and an outer gimbal containing the sprung shell and inner gimbal. A passive vibration isolator is connected between the sprung shell and the outer gimbal and has two symmetrical arrays of dampened coil springs located on opposite sides of the sprung shell.

Claims

1. A stabilized platform system for isolating a payload from angular motion and translational and angular vibration of a supporting structure, said platform system having:

an inner gimbal for carrying the payload,

a sprung shell containing and carrying the inner gimbal in a manner permitting the inner gimbal a limited amount of angular movement relative thereto about pitch, roll and yaw axes,

an outer gimbal containing the sprung shell and inner gimbal, and

a passive vibration isolator connected between the sprung shell and the outer gimbal and having two symmetrical arrays of dampened coil springs located on opposite sides of the sprung shell.

2. A stabilized platform system according to claim 1 including an array of at least three magnetic torque motors, each motor having an electrically energizable coil portion carried by the sprung shell and a magnetic structure portion carried by the inner gimbal, each magnetic torque motor having an active axis along which an inner gimbal positioning force can be applied but having freedom of movement about the other two axes, and a controller for controlling energization of the motors to apply controlled moments to the inner gimbal about any axis of rotation.

3. A stabilized platform according to claim 1 having at least one capacitive angle sensor having a first portion carried by the sprung shell and a second portion carried by the inner gimbal with an air gap between said first and second portions, said capacitive angle sensor being responsive to relative motion between the first and second portions to provide a signal indicative of the angular position of the inner gimbal relative to the sprung shell.

4. A stabilized platform system according to claim 1 wherein each array of dampened coil springs of the passive vibration isolator extends completely around the sprung shell on the respective side thereof to provide compliance in three orthogonal directions.

5. A stabilized platform system according to claim 1 also including eccentric mechanism connecting the passive vibration isolator to the outer gimbal and responsive to angular movement of the outer gimbal to position the sprung shell at an optimum location in the outer gimbal by correcting static displacement of the isolator.

6. A stabilized platform system according to claim 1 wherein the inner gimbal carries at least one fiber optic gyro operable to provide a signal of angular movement of the inner gimbal about a pre-determined axis.

7. A stabilized platform system according to claim 1 also including a first mounting member carrying the outer gimbal, said outer gimbal being angularly adjustable relative to the first mounting member about an elevation axis.

8. A stabilized platform system according to claim 7 also including a second mounting member carrying the first mounting member, the first mounting member being angularly adjustable relative to the second mounting member about a horizontal axis perpendicular to the elevation axis.

9. A stabilized platform system according to claim 8 wherein the second mounting member is itself angularly adjustable about a vertical axis.

10. A stabilized platform system according to claim 1 also including a mounting member carrying the outer gimbal, the outer gimbal being angularly adjustable relative to the mounting member about an elevation axis, said mounting member itself being angularly adjustable about a vertical axis.

11. A stabilized platform system according to claim 1 wherein the sprung shell has a main body portion and a pair of shell disks on opposite sides thereof connected to the main body portion only at a radially inner location, and said coil springs are connected to the shell disks at a radially outer location.