摘要 |
An exposure apparatus includes a motion control system, the motion control system including a structure, a plurality of actuators to apply forces to the structure, respectively, and a plurality of sensors to sense motion states of the structure, respectively. The apparatus includes a pseudo-random signal generator to generate a plurality of pseudo-random signals and to apply the plurality of pseudo-random signals to the plurality of actuators, the plurality of pseudo-random signals being equal in number to a number of degrees of freedom of the motion control system, a storage unit to store a first plurality of time-series data obtained by the plurality of sensors with a second plurality of time-series data corresponding to the plurality of pseudo-random signals, and a characteristic deriving unit to derive a characteristic of the motion control system based on the first and second plurality of time-series data.
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