Patent attributes
In a robotic system having a two-axis robotic wrist connected to a reference member, the wrist has a movable member movable relative to the reference member in pitch and yaw. A first serial chain linkage connects the movable member to the reference member and a second serial chain linkage connects the movable member to the reference member in parallel relationship with the first serial chain linkage. The linkages are configured to constrain the movable to spherical movement, and such that the robotic wrist is non-singular, non-overconstrained, and non-overactuated. Actuation of a pair of revolute joints connected to the reference member deflects the movable member in pitch and yaw. The roll angle resulting from deflection in pitch and yaw is that of an intersecting-shaft constant-velocity coupling connecting the reference member to the movable member.