Direct drive controller with haptic feedback

Abstract

A reliable and cost-efficient direct drive force feedback motor is suitable for joystick applications, allowing multiple degrees of output freedom, requiring no coil commutation, and permitting compact packaging. A multiple degree-of-freedom motor consistent with the invention comprises an output shaft, a stator, and a rotor. The stator comprises first and second lamination stacks, each lamination stack having an interior curved surface and a coil wound thereon, the lamination stacks being disposed adjacent the output shaft. The rotor is fixed to the output shaft and movably supported adjacent the stator with an air gap disposed between the rotor and the stator, the rotor including at least one magnet disposed thereon and being movable along the interior curved surface of the lamination stacks in directions defining at least first and second degrees of freedom. Energization of the coil of the first lamination stack establishes a first magnetic field to urge the output shaft to rotate in a first plane, and energization of the coil of the second lamination stack establishes a second magnetic field to urge the output shaft to rotate in a second plane substantially orthogonal to the first plane.

1 - 26 . (canceled) 
   
   
       27 : A lamination stack for use in a stator of a motor having an output shaft, comprising:
 a plurality of laminations stacked flat against one another and parallel to one another;   wherein the laminations near the edge of the stack are disposed slightly closer to the output shaft to form a stepped concave surface about the longitudinal axis of the output shaft in a plane orthogonal to a side surface of the plurality of laminations.   
   
   
       28 : The lamination stack of  claim 27 , wherein the shape of the stepped concave surface of the plurality of laminations about an equator of the plurality of laminations approximates an arc having a constant radius in a plane orthogonal to a side surface of the plurality of laminations. 
   
   
       29 - 31 . (canceled) 
   
   
       32 : A stator coil winding for use in a motor comprising an output shaft having a rotor coupled thereto and a longitudinal axis, said winding comprising:
 a spiral coil having a plurality of turns therein, wherein said coil is disposed adjacent said output shaft and is wound around an axis generally parallel to the longitudinal axis of said output shaft.   
   
   
       33 : The stator coil winding of  claim 32 , wherein said spiral coil is disposed relative to said rotor such that torque control over said output shaft in a degree of freedom is exerted by selective provision of a current having a predetermined direction and magnitude to said spiral coil. 
   
   
       34 : The stator coil winding of  claim 32 , wherein said spiral coil is wound around a lamination stack. 
   
   
       35 : The stator coil winding of  claim 34 , wherein said lamination stack has an interior curved surface. 
   
   
       36 : The stator coil winding of  claim 34 , wherein said lamination stack has a plurality of slots formed therein. 
   
   
       37 : The stator coil winding of  claim 36 , wherein said slots lie in planes substantially parallel to one another. 
   
   
       38 : The stator coil winding of  claim 36 , wherein said lamination stack comprises a plurality of laminations radially disposed about a center point, with a plane of each lamination extending through said center point. 
   
   
       39 : The stator coil winding of  claim 36 , wherein said lamination stack has no slots formed therein. 
   
   
       40 : The stator coil winding of  claim 36 , wherein said spiral coil is wound around a single solid ferrite mass. 
   
   
       41 : The stator coil winding of  claim 32 , wherein said coil has a substantially rectangular cross-section. 
   
   
       42 : A stator coil winding method for use in a motor comprising an output shaft having a rotor coupled thereto and a longitudinal axis, said method comprising:
 winding a spiral coil having a plurality of turns therein around an axis generally parallel to the longitudinal axis of said output shaft; and   disposing said coil adjacent said output shaft.   
   
   
       43 : The method of  claim 42 , further comprising:
 selectively providing controlling a current having a predetermined direction and magnitude to said coil to control the torque of said output shaft in a degree of freedom.   
   
   
       44 - 46 . (canceled) 
   
   
       47 : A rotor for use in a motor having an output shaft, comprising:
 a linkage member adapted for coupling to the output shaft of said motor, said linkage member having only two arms extending therefrom, each said arm coupled to a magnet.   
   
   
       48 : The rotor of  claim 47 , wherein said linkage member is a magnet. 
   
   
       49 : The rotor of  claim 47 , wherein at least one said magnet coupled to the arm of said linkage member is faceted. 
   
   
       50 : The rotor of  claim 47 , wherein at least one said magnet coupled to the arm of said linkage member has a spherical exterior surface. 
   
   
       51 : The rotor of  claim 47 , wherein said arms extend in substantially orthogonal directions relative to one another. 
   
   
       52 : The rotor of  claim 47 , wherein each arm comprises a downward turned portion. 
   
   
       53 : The rotor of  claim 52 , wherein the downward turned portions of said arms lie in planes substantially orthogonal to one another. 
   
   
       54 . (canceled)