초록 ▼

Selective compliance in up to six degress of freedom in a magnetically levitated fine motion device, or robot wrist, with limited motion in X,Y,Z, ROLL, PITCH, YAW, is provided by controlled actuation currents applied to six electrodynamic forcer elements. The wrist has a stator support base definin

Selective compliance in up to six degress of freedom in a magnetically levitated fine motion device, or robot wrist, with limited motion in X,Y,Z, ROLL, PITCH, YAW, is provided by controlled actuation currents applied to six electrodynamic forcer elements. The wrist has a stator support base defining a dual periphery, carrying a number of stator magnet units. A shell flotor unit nests within the stator support base dual periphery, and carries forcer coils at locations corresponding to respective magnet units. The magnet unit and related flotor coil form a forcer element. There are a number of forcer elements. The vector sum of all the translational forces and rotational torques established at the forcer elements determines the X,Y,Z, ROLL, PITCH, and YAW motion of the flotor. The flotor carries an end effector which may be a tool. Position and orientation of the flotor is monitored by light emitting diodes and lateral effect cells. Coil currents are controlled as a composite of present position, desired final position, and desired compliance. As the fine motion device approaches its final position, the control unit changes forcer coil current patterns at various sets of forcer elements, to provide selected compliance in one or more degrees of freedom while approaching and finally while maintaining the desired position. Cooling is provided as needed; docking and locking provision is made to allow de-energizing the coils for cooling, motion of the base, or shutdown.

대표청구항 ▼

A six-degree-of-freedom fine motion device, having but a single moving part, comprising: (a) a stator support unit (9) defining a base and a dual enclosure having dual walls upthrust from the base to define a dual periphery; (b) a multiplicity of forcer magnets (4) disposed at spaced positions about

A six-degree-of-freedom fine motion device, having but a single moving part, comprising: (a) a stator support unit (9) defining a base and a dual enclosure having dual walls upthrust from the base to define a dual periphery; (b) a multiplicity of forcer magnets (4) disposed at spaced positions about said dual periphery; (c) a flotor unit (1) having a related periphery nested in said dual periphery of said stator support unit (9); (d) forcer elements (5) including a multiplicity of forcer element flotor coils (3) arrayed about said periphery of said flotor unit (1) in active juxtaposition with said forcer magnets (4); (e) position and orientation sensing means (6) arrayed about said dual periphery of said stator support unit (9) and about said periphery of said flotor unit (1) to sense the relative positions and orientations of said stator support unit and said flotor unit; and (f) control means connected to said position and orientation sensing means (6) in feedback mode, for providing respective forcer elements (5) with electrodynamic actuation appropriate to maintain equilibrium at a desired starting position and orientation, appropriate to cause motion to a desired final position and orientation according to a force-to-displacement ratio K, and appropriate to provide a desired compliance in at least one degree of freedom by selectively lessening the force-to-displacement ratio K in a related set of forcer elements (5).