Patent attributes
A user interface system comprises a plurality of linkages connected between a platform and a base. The linkages permit motion of the platform over at least a portion of a spherical surface. A support assembly coupled between the platform and the base comprises a spherical joint having a center of rotation substantially concentric with a center of the spherical surface. The spherical joint constrains motion of the platform to the spherical surface. The system may include a sensor corresponding to each linkage. Each sensor may be coupled to sense a movement of its corresponding linkage in response to motion of the platform over the portion of the spherical surface. A user-manipulable handle may be coupled to the platform so that the user can move the platform.