Magnetic soft stops for gimbals

Abstract

A gimbal arrangement includes a static structure, a gimbal supported for rotation relative to the static structure, an actuator operably connected to the gimbal and configured to rotate the gimbal relative to the static structure, and a magnetic soft stop. The magnetic soft stop is connected between the static structure and the gimbal to limit rotation of the gimbal relative to the static structure to within a predetermined range. Sensor systems and imaging methods are also described.

What is claimed is: 
     
         1 . A gimbal arrangement, comprising:
 a static structure;   a gimbal supported for rotation relative to the static structure;   an actuator operably connected to the gimbal and configured to rotate the gimbal relative to the static structure; and   a magnetic soft stop connected between the static structure and the gimbal to limit rotation of the gimbal relative to the static structure to within a predetermined range.   
     
     
         2 . The gimbal arrangement as recited in  claim 1 , wherein the magnetic soft stop includes an electromagnet. 
     
     
         3 . The gimbal arrangement as recited in  claim 2 , wherein the electromagnet is fixed relative to the static structure. 
     
     
         4 . The gimbal arrangement as recited in  claim 2 , wherein the electromagnet is fixed relative to the gimbal. 
     
     
         5 . The gimbal arrangement as recited in  claim 1 , wherein the magnetic soft stop includes a permanent magnet. 
     
     
         6 . The gimbal arrangement as recited in  claim 5 , wherein the permanent magnet is fixed relative to the static structure. 
     
     
         7 . The gimbal arrangement as recited in  claim 5 , wherein the permanent magnet is fixed relative to the gimbal. 
     
     
         8 . The gimbal arrangement as recited in  claim 1 , wherein the magnetic soft stop includes a ferromagnetic body. 
     
     
         9 . The gimbal arrangement as recited in  claim 8 , wherein the ferromagnetic body is fixed relative to the static structure. 
     
     
         10 . The gimbal arrangement as recited in  claim 8 , wherein the ferromagnetic body is fixed relative to the gimbal. 
     
     
         11 . The gimbal arrangement as recited in  claim 1 , wherein there is no mechanical hard stop arranged between the gimbal and the static structure. 
     
     
         12 . The gimbal arrangement as recited in  claim 1 , wherein the magnetic soft stop conforms in fit and form of a mechanical hard stop for a DB-110 sensor system. 
     
     
         13 . The gimbal arrangement as recited in  claim 1 , further comprising a controller operably connected to the magnetic soft stop, wherein the controller is disposed in communication with a memory having instructions recorded on the memory to:
 activate the magnetic hard stop; and   limit rotation of the gimbal relative to the static structure to a predetermined range.   
     
     
         14 . The gimbal arrangement as recited in  claim 1 , further comprising a sensor fixed relative to the gimbal. 
     
     
         15 . The gimbal arrangement as recited in  claim 1 , wherein the gimbal is arranged about a roll axis relative to the static structure. 
     
     
         16 . The gimbal arrangement as recited in  claim 1 , wherein the gimbal is arranged about a pitch axis relative to the static structure. 
     
     
         17 . The gimbal arrangement as recited in  claim 1 , wherein the gimbal is a first gimbal and further comprising a second gimbal, wherein the magnet is a first magnet, and further comprising:
 a second gimbal supported for rotation relative to the first gimbal; and   a second magnet arranged between the first gimbal and the second gimbal, wherein the second magnetic soft stop is connected between the second gimbal and the first gimbal to limit rotation of the second gimbal relative to the first gimbal.   
     
     
         18 . A sensor system, comprising:
 a gimbal arrangement as recited in  claim 1 ;   a sensor fixed relative to the gimbal; and   a controller operably connected to the magnetic soft stop, wherein the controller is disposed in communication with a memory having instructions recorded on the memory to:
 activate the magnetic hard stop; and 
 limit rotation of the gimbal relative to the static structure to a predetermined range. 
   
     
     
         19 . The sensor system as recited in  claim 1 , wherein magnetic soft stop comprises:
 an electromagnet fixed relative to one of the static structure and the gimbal; and   a permanent magnet fixed relative to the other of the static structure and the gimbal, wherein there is no mechanical hard stop arranged between the gimbal and the static structure.   
     
     
         20 . An imaging method, comprising:
 at a gimbal arrangement comprising a static structure, a gimbal supported for rotation relative to the static structure, an actuator operably connected to the gimbal and configured to rotate the gimbal relative to the static structure, and a magnetic soft stop connected between the static structure and the gimbal to limit rotation of the gimbal relative to the static structure to within a predetermined range,   limiting rotation of the gimbal relative to the static structure to a predetermined range by communicating a magnetic force between the gimbal and the static structure.