GIMBAL SYSTEMS PROVIDING HIGH-PRECISION IMAGING CAPABILITIES IN A COMPACT FORM-FACTOR

• US 20140049643A1
• Filed: 08/10/2013
• Published: 02/20/2014
• Est. Priority Date: 08/16/2012
• Status: Active Grant

• Current Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Original Assignee: Ascendant Engineering Solutions
• Inventors: Segerstrom, Eric, Mooty, Greg, Miller, Rick
• Granted Patent: US 9,435,520 B2
• Time in Patent Office: Days
• US Class Current: 348/144
• CPC Class Codes: B64D 47/08 Arrangements of cameras
• CPC Class Codes: B64U 20/87 Mounting of imaging devices, e.g. mounting of gimbals
• CPC Class Codes: F21V 21/30 Pivoted housings or frames
• CPC Class Codes: F21V 5/00 Refractors for light sources characterised by cooling arrangements F21V29/504
• CPC Class Codes: F41G 3/145 using a target illuminator
• CPC Class Codes: F41G 3/22 for vehicle-borne armament, e.g. on aircraft
• CPC Class Codes: G01J 3/0202 Mechanical elements; Supports for optical elements
• CPC Class Codes: G01J 3/0289 Field-of-view determination; Aiming or pointing of a spectrometer; Adjusting alignment; Encoding angular position; Size of measurement area; Position tracking
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• 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

Abstract

A small form-factor gimbal system that provides for stabilization of payload assets in a manner that provides improved stabilization capability. Such a small form-factor gimbal system provides for precision payload asset steering functionality through integration of an inertially stabilized two-axis gimbal in combination with a beam stabilization mechanism (BSM). In a preferred embodiment, such a small form-factor gimbal system has a gimbal diameter of about 5″ or less and employs a laser assembly having a Coudé path arrangement in which the laser beam passes from the azimuth subassembly to the elevation subassembly along the elevation subassembly rotational axis.

Claims

1. A two-axis gimbal system, comprising:

a gimbal assembly including a base subassembly, an azimuth subassembly having a rotatably mounted on the base subassembly in a manner enabling the azimuth subassembly to rotate about a first rotational axis, and an elevation subassembly rotatably mounted on the azimuth subassembly in a manner enabling the elevation subassembly to rotate about a second rotational axis, wherein the second rotational axis extends substantially perpendicular to the first rotational axis;

a laser amounted on the azimuth subassembly;

a first laser light beam steering device amounted on the azimuth subassembly, wherein the first laser light beam steering device redirects a laser light output of the laser from a first laser light beam travelling direction to a second laser light beam travelling direction and wherein the second laser light beam travelling direction is substantially along the second rotational axis;

a second laser light beam steering device mounted on the elevation subassembly for redirecting the laser light output from along the second laser light beam travelling direction to along a third laser light beam travelling direction; and

a micro-electro-mechanical system (MEMS) gyro mounted on the elevation subassembly.

2. The two-axis gimbal system of claim 1 wherein the second laser light beam steering device includes a fast steering mirror (FSM).

3. The two-axis gimbal system of claim 2, further comprising:

a laser light detecting device mounted on the elevation subassembly.

4. The two-axis gimbal system of claim 3 wherein the first laser light detecting device includes a short wavelength infrared (SWIR) camera.

5. The two-axis gimbal system of claim 3, further comprising:

a long wavelength infrared (LWIR) camera mounted on the elevation subassembly.

6. The two-axis gimbal system of claim 4, further comprising:

a SWIR illuminator mounted on the elevation subassembly.

7. The two-axis gimbal system of claim 1 wherein the gimbal subassembly movement apparatus of the azimuth subassembly and the gimbal subassembly movement apparatus of the elevation subassembly each include direct drive torque motors exerting rotational force on a respective one of the gimbal subassemblies.

8. The two-axis gimbal system of claim 7 wherein:

the azimuth subassembly includes an angular position sensor for sensing angular position about the azimuth subassembly rotational axis; and

the elevation subassembly includes an angular position sensor for sensing angular position about the elevation subassembly rotational axis.

9. The two-axis gimbal system of claim 1, further comprising:

a low-latency target tracker apparatus mounted on the gimbal assembly, wherein the low latency target tracker apparatus includes one or more target imaging cameras for generating target image information; and

wherein the one or more target imaging cameras are mounted on the elevation subassembly.

10. The two-axis gimbal system of claim 1, further comprising:

a beam stabilization mechanism mounted on the gimbal assembly;

wherein the beam stabilization mechanism is coupled to an output signal of the MEMS gyro, to an input signal of a gimbal subassembly movement apparatus of the azimuth subassembly and to an input signal of a gimbal subassembly movement apparatus of the elevation subassembly.

11. The two-axis gimbal system of claim 10 wherein:

the beam stabilization mechanism comprises a low-latency target tracker apparatus; and

the low latency target tracker apparatus includes one or more target imaging cameras for generating target image information; and

the one or more target imaging cameras are mounted on the elevation subassembly.

12. The two-axis gimbal system of claim 11, further comprising:

an infrared camera mounted on the elevation subassembly; and

a visible light camera mounted on the elevation subassembly;

wherein the low-latency target tracker apparatus comprises at least one of the infrared camera and the visible light.

13. The two-axis gimbal system of claim 12 wherein:

the beam stabilization mechanism comprises the second laser light beam steering device; and

the second laser light beam steering device includes a fast steering mirror (FSM).

14. The two-axis gimbal system of claim 13 wherein:

the gimbal subassembly movement apparatus of the azimuth subassembly and the gimbal subassembly movement apparatus of the elevation subassembly each include direct drive torque motors exerting rotational force on a respective one of the gimbal subassemblies;

the azimuth subassembly includes an angular position sensor for sensing angular position about the azimuth subassembly rotational axis; and

the elevation subassembly includes an angular position sensor for sensing angular position about the elevation subassembly rotational axis.

15. A two-axis gimbal system, comprising:

a gimbal assembly including a base subassembly, an azimuth subassembly having a rotatably mounted on the base subassembly in a manner enabling the azimuth subassembly to rotate about a first rotational axis, and an elevation subassembly rotatably mounted on the azimuth subassembly in a manner enabling the elevation subassembly to rotate about a second rotational axis, wherein the second rotational axis extends substantially perpendicular to the first rotational axis;

a laser assembly mounted on the azimuth subassembly, wherein the laser assembly includes a laser light beam steering device that redirects a laser light output of a laser of the laser assembly from a first laser light beam travelling direction to a second laser light beam travelling direction and wherein the second laser light beam travelling direction is substantially along the second rotational axis;

a short wavelength infrared (SWIR) camera mounted on the elevation subassembly;

a SWIR illuminator mounted on the elevation subassembly;

a visible light camera mounted on the elevation subassembly;

a micro-electro-mechanical system (MEMS) gyro mounted on the elevation subassembly; and

a beam stabilization mechanism mounted on the gimbal assembly, wherein the beam stabilization mechanism includes a fast steering mirror mounted on the elevation subassembly for redirecting the laser light output from along the second laser light beam travelling direction to along a third laser light beam travelling direction and wherein the beam stabilization mechanism is coupled to an output signal of the MEMS gyro, to an output signal of the SWIR camera, to an input signal of a gimbal subassembly movement apparatus of the azimuth subassembly and to an input signal of a gimbal subassembly movement apparatus of the elevation subassembly.

16. The two-axis gimbal system of claim 15 wherein:

the beam stabilization mechanism includes a low-latency target tracker apparatus mounted on the gimbal assembly;

the low latency target tracker apparatus includes one or more target imaging cameras for generating target image information; and

the one or more target imaging cameras are mounted on the elevation subassembly.

17. The two-axis gimbal system of claim 16 wherein:

the gimbal subassembly movement apparatus of the azimuth subassembly and the gimbal subassembly movement apparatus of the elevation subassembly each include direct drive torque motors exerting rotational force on a respective one of the gimbal subassemblies;

the azimuth subassembly includes an angular position sensor for sensing angular position about the azimuth subassembly rotational axis; and

the elevation subassembly includes an angular position sensor for sensing angular position about the elevation subassembly rotational axis.