Abstract: The present application discloses a multi-axis motion system and methods of use, using an air bearing configured to position a semiconductor wafer chuck support relative to an inspection device. The air bearing includes a vacuum clamping function operative to secure the wafer chuck support to a surface formed on the underside of a structure that houses the inspection device. In one embodiment, the system includes a first positioner operative to position a carriage assembly in a first direction, the carriage assembly including a second positioner and a third positioner operative to selectively and independently travel in a second direction orthogonal to the first direction. The chuck support is secured to the positioners by one or more pivoting decoupling systems configured to transmit actuation forces from the positioners in the first and second directions, allowing the chuck support to be decoupled from the positioners when the chuck support is vacuum clamped to the underside of the structure.

Abstract: A method for compensating for accuracy errors of a hexapod is disclosed, said hexapod comprising a base, an actuation assembly having six linear translation actuators, a control unit, and a movable carriage comprising a platform connected to the base by means of the actuation assembly. The method includes a measurement step for determining geometry and positioning errors on the hexapod, the measurement step including sub-steps for determining positioning errors of the pivot centers on the carriage and on the base, for determining length errors of the actuators and for measuring positioning errors of the actuators along the path thereof, the compensation method also including a step for calculating, from measurements taken, error compensation values and a step for applying said error compensation values to the control unit of the hexapod, during subsequent use of said hexapod.

Abstract: A method for compensating for accuracy errors of a hexapod is disclosed, said hexapod comprising a base, an actuation assembly having six linear translation actuators, a control unit, and a movable carriage comprising a platform connected to the base by means of the actuation assembly. The method includes a measurement step for determining geometry and positioning errors on the hexapod, the measurement step including sub-steps for determining positioning errors of the pivot centers on the carriage and on the base, for determining length errors of the actuators and for measuring positioning errors of the actuators along the path thereof, the compensation method also including a step for calculating, from measurements taken, error compensation values and a step for applying said error compensation values to the control unit of the hexapod, during subsequent use of said hexapod.

Abstract: An apparatus comprises a brushless motor, driver, incremental displacement sensor, and processor. The motor has a rotor, stator, and electrical terminals accepting a drive signal. The initial phase of the rotor is unknown. The driver is connected to the electrical terminals and produces the drive signal. The displacement sensor is configured to measure a displacement of the rotor and to produce an output signal. The processor has an input receiving the output signal and an output connected to the driver. The processor causes the driver to produce the drive signal according to a predetermined function of time, observes the output signal from the displacement sensor resulting from the drive signal, and performs mathematical computations on the basis of the observed output signal and a model of dynamic behavior of the motor to estimate the initial phase of the rotor.

Abstract: An apparatus comprises a brushless motor, driver, incremental displacement sensor, and processor. The motor has a rotor, stator, and electrical terminals accepting a drive signal. The initial phase of the rotor is unknown. The driver is connected to the electrical terminals and produces the drive signal. The displacement sensor is configured to measure a displacement of the rotor and to produce an output signal. The processor has an input receiving the output signal and an output connected to the driver. The processor causes the driver to produce the drive signal according to a predetermined function of time, observes the output signal from the displacement sensor resulting from the drive signal, and performs mathematical computations on the basis of the observed output signal and a model of dynamic behavior of the motor to estimate the initial phase of the rotor.