Abstract: A method for moving a stage relative to a base includes coupling a magnet assembly to the stage; coupling an array of coils to the base; and directing current to at least one of the coils with a control system that includes a processor to generate a force that levitates the stage relative to the base and moves the stage relative to the base. In one embodiment, the control system generates at least one current command that levitates and moves the stage while inhibiting the excitation of a first targeted flexible mode.

Abstract: A method for moving a stage relative to a base includes coupling a magnet assembly to the stage; coupling an array of coils to the base; and directing current to at least one of the coils with a control system that includes a processor to generate a force that levitates the stage relative to the base and moves the stage relative to the base. In one embodiment, the control system generates at least one current command that levitates and moves the stage while inhibiting the excitation of a first targeted flexible mode.

Abstract: A stage assembly for positioning a device includes: (i) a stage that retains the device; (ii) a base; (iii) a mover assembly that moves the stage along a first axis, along a second axis, and along a third axis relative to the base; (iv) a magnetic sensor system that monitors the movement of the stage along the first, second and third axes, the magnetic sensor system generating a magnetic sensor signal; (v) a second sensor system that monitors the movement of the stage along the first, second and third axes, the second sensor system generating a second sensor signal; and (vi) a control system that controls the mover assembly using at least one of the magnetic sensor signal and the second sensor signal.

Abstract: According to an aspect of the present invention, an apparatus includes a stage, at least a first coil, at least a first magnet, a plurality of Hall sensors, and a stage position estimation module. The first coil is included in a coil array that is a part of a coil arrangement. The first magnet is configured to cooperate with the first coil to form a motor that drives the stage. The dynamics model arrangement obtains a current command provided to the first coil and provides a first signal based on the current command. The Hall sensors are included in the coil arrangement, and are configured to measure a flux that includes a magnetic component and a coil component. The stage position estimation module is configured to obtain the flux and the first signal, and to process the flux and the first signal to estimate a position of the stage.

Abstract: According to one aspect, an apparatus includes a stage, a motor to move the stage, an amplifier, and a controller. The motor has at least a first coil and a second coil, and the amplifier is configured to selectively provide current to either the first coil or the second coil. The controller is configured to control force generated by the motor. When moving the stage, the controller controls the motor force by using the amplifier to provide current to the first coil, smoothly reducing a force generated by the first coil before the stage moves to a predetermined switching location so that the coil is generating substantially no force at the switching location, switching the amplifier so that the amplifier provides current to the second coil, and smoothly increasing a force generated by the second coil after the stage moves past the predetermined switching location.

Abstract: A stage assembly for positioning a device includes: (i) a stage that retains the device; (ii) a base; (iii) a mover assembly that moves the stage along a first axis, along a second axis, and along a third axis relative to the base; (iv) a magnetic sensor system that monitors the movement of the stage along the first, second and third axes, the magnetic sensor system generating a magnetic sensor signal; (v) a second sensor system that monitors the movement of the stage along the first, second and third axes, the second sensor system generating a second sensor signal; and (vi) a control system that controls the mover assembly using at least one of the magnetic sensor signal and the second sensor signal.