Methods and systems for controllably moving multiple moveable stages in a displacement device

A displacement device comprising:

• a stator comprising one or more stator tiles, each stator tile comprising:
• an x-trace layer comprising a plurality of x-trace groups, each x-trace group comprising a plurality of electrically conductive x-traces which extend in a stator-x direction across the stator tile and into which currents may be independently driven;
• a y-trace layer comprising a plurality of y-trace groups, each y-trace group comprising a plurality of electrically conductive y-traces which extend in a stator-y direction across the stator tile and into which currents may be independently driven;
• the x-trace layer and the y-trace layer overlapping one another in a stator-z direction;
• the stator-x direction and the stator-y direction non-parallel to one another;
• a plurality of moveable stages, each moveable stage comprising:
• a first magnet array comprising:
• a plurality of first magnetization segments linearly elongated in a stage-x direction, each first magnetization segment having a corresponding magnetization direction orthogonal to the stage-x direction and a plurality of second magnetization segments linearly elongated in a stage-y direction, each second magnetization segment having a corresponding magnetization direction orthogonal to the stage-y direction;
• and
• the stage-x direction and the stage-y direction non-parallel to one another;
• and
• one or more amplifiers connected to drive currents in the x-traces and the y-traces to move a first moveable stage and a second moveable stage relative to the stator wherein for at least a first portion of a time where the first moveable stage overlaps with a first x-trace of a first stator tile in the stator-z direction and a first magnet array of the second moveable stage overlaps the first x-trace of the first stator tile in the stator-z direction, controllably driving current in the first x-trace of the first tile based at least in part on a first amount of overlap in the stator-z direction of the first magnet array of the first moveable stage with the first-x-trace of the first tile and a second amount of overlap in the stator-z direction of the first magnet array of the second moveable stage with the first-x-trace of the first tile.

A displacement device comprising:

• a stator comprising one or more stator tiles, each stator tile comprising:
• an x-trace layer comprising a plurality of x-trace groups, each x-trace group comprising a plurality of electrically conductive x-traces which extend in a stator-x direction across the stator tile and into which currents may be independently driven;
• a y-trace layer comprising a plurality of y-trace groups, each y-trace group comprising a plurality of electrically conductive y-traces which extend in a stator-y direction across the stator tile and into which currents may be independently driven;
• the x-trace layer and the y-trace layer overlapping one another in a stator-z direction;
• the stator-x direction and the stator-y direction non-parallel to one another;
• a plurality of moveable stages, each moveable stage comprising:
• a first magnet array comprising a plurality of first magnetization segments linearly elongated in a stage-x direction, each first magnetization segment having a corresponding magnetization direction orthogonal to the stage-x direction and at least two of the first magnetization segments having magnetization directions that are different from one another;
• and
• a second magnet array comprising a plurality of second magnetization segments linearly elongated in a stage-y direction, each second magnetization segment having a magnetization direction orthogonal to the stage-y direction and at least two of the second magnetization segments having magnetization directions that are different from one another;
• the stage-x direction and the stage-y direction non-parallel to one another;
• and
• a controller configured to direct one or more amplifiers to drive currents in the x-traces and the y-traces to move a first moveable stage and a second moveable stage relative to the stator;
• wherein the controller comprises:
• a trajectory generator configured to generate reference positions for each moveable stage;
• and
• a current command generator configured to generate current control signals for directing the one or more amplifiers to drive currents in the x-traces and the y-traces, the current command generator configured to generate the current control signals based at least in part on the reference positions for each moveable stage.