Gimbal system with airflow

1. A gimbal system, comprising:

a gimbal apparatus including a payload and also including a gimbal mount supporting a first gimbal and a second gimbal, the first gimbal being coupled pivotally to the gimbal mount and the second gimbal being coupled pivotally to and supported by the first gimbal and also being coupled to and supporting the payload such that the gimbal apparatus orients the payload by pivotal movement of the first and second gimbals relative to the gimbal mount about at least two nonparallel axes; and

a fan mounted to the first gimbal.

2. The gimbal system of claim 1 , wherein the payload detects electromagnetic radiation.

3. The gimbal system of claim 2 , wherein the payload includes a detection portion of an imaging system, and wherein the detection portion detects visible radiation, infrared radiation, or both.

4. The gimbal system of claim 1 , wherein the payload includes a laser.

5. The gimbal system of claim 1 , wherein the gimbal apparatus further includes at least one other gimbal, wherein the payload is supported by the at least one other gimbal and is pivotally coupled to the second gimbal via the at least one other gimbal.

6. The gimbal system of claim 1 , wherein the first gimbal and the second gimbal are separated by a gap, and wherein the fan is positioned to drive air through the gap.

7. The gimbal system of claim 6 , wherein the gap has a substantially semi-spherical shape.

8. The gimbal system of claim 6 , wherein portions of the gap have a smaller cross-sectional area than other portions of the gap, increasing air flow along at least one relatively hotter portion of a surface of the first and second gimbals.

9. The gimbal system of claim 1 , wherein the payload is enclosed by the second gimbal.

10. The gimbal system of claim 9 , wherein the payload is hermetically sealed inside the second gimbal, and wherein the second gimbal is at least substantially spherical.

11. The gimbal system of claim 1 , further comprising a controller that operates the fan according to a temperature measured by a temperature sensor operatively coupled to the controller.

12. The gimbal system of claim 11 , wherein the second gimbal encloses the payload, and wherein the temperature sensor measures a temperature associated with the second gimbal.

13. The gimbal system of claim 1 , wherein the first gimbal is an outer gimbal, wherein the second gimbal is an inner gimbal, and wherein the outer gimbal defines a channel in which the fan is disposed.

14. The gimbal system of claim 1 , further comprising:

one or more drivers configured to drive pivotal movement of the first and second gimbals; and

a controller configured to control operation of the drivers.

15. The gimbal system of claim 1 , wherein the gimbal apparatus and the fan are configured such that operation of the fan drives airflow through a gap disposed between the first and second gimbals.

16. A method of cooling a gimbal system that includes a gimbal apparatus including a payload and also including a gimbal mount supporting a first gimbal and a second gimbal, the first gimbal being coupled pivotally to the gimbal mount and the second gimbal being coupled pivotally to and supported by the first gimbal and also being coupled to and supporting the payload such that the gimbal apparatus orients the payload by pivotal movement of the first and second gimbals relative to the gimbal mount about at least two nonparallel axes, the method comprising:

operating a fan to drive airflow through a gap disposed between the first and second gimbals.

17. The method of claim 16 , further comprising a step of sensing a temperature associated with the second gimbal, wherein the step of operating a fan includes a step of operating a fan based on the step of sensing a temperature.

18. A gimbal system, comprising:

a gimbal apparatus including a payload with at least one detector and also including a gimbal mount supporting a first gimbal and a second gimbal, the first gimbal being coupled pivotally to the gimbal mount and the second gimbal being coupled pivotally to and supported by the first gimbal and also being coupled to and supporting the payload such that the gimbal apparatus orients the payload by pivotal movement of the first and second gimbals relative to the gimbal mount about at least two nonparallel axes;

one or more drivers configured to drive pivotal movement of the first and second gimbals;

a controller configured to control operation of the drivers; and

a fan attached to and supported by the gimbal apparatus,

wherein the fan and the first and second gimbals are configured such that operation of the fan drives airflow through a gap disposed between the first and second gimbals.

19. The gimbal system of claim 18 , wherein the payload detects both visible radiation and infrared radiation.

20. The gimbal system of claim 18 , wherein the payload includes a laser.

21. The gimbal system of claim 18 , wherein the first gimbal has an outer wall and an inner wall, and wherein the fan is disposed generally between the outer wall and the inner wall.

22. The gimbal system of claim 18 , wherein the fan is mounted to the first gimbal.

23. The gimbal system of claim 22 , wherein the first gimbal defines a tunnel, and wherein the fan is disposed in the tunnel.

24. The gimbal system of claim 22 , wherein the fan is disposed outside the first gimbal.

25. The gimbal system of claim 18 , wherein the fan and first and second gimbals are configured such that air from outside the gimbal apparatus flows through the gap.