Accurate object positioner using proportional EM actuator - has push=pull stages with laser measurement of displacement to supply data to control stages operating in MM range

摘要

A micropositioner, with a bandwidth of around 100 Hz, has rotationally symmetric armature (3) within a core (1). An airgap exists between the core and armature. Together with the windings (2,7) a pair of e.m. actuators is produced. At one end of the armature a mirror (10) is installed. The range of motion is in the millimetre range. A laser (12) is reflected off the mirror to provide measurement of the displacement and this provides feedback to regulating circuits (16,17) that adjust the excitation current to the coils. A digital processor (20) provides a reference value for the displacement. USE/ADVANTAGE - Provides high dynamic force over extremely small displacement range. Can dynamically correct position deviations caused by shaking of astronomical telescope.