Laser pointing and tracking using a completely electromagnetically suspended precision actuator

The system description and experimental results of control strategy for laser acquisition, reacquisition, pointing, and tracking are discussed. This method uses an electromagnetically suspended precision actuator for laser pointing and tracking. Magnetic levitation technology has been used in high performance motion control system due to its noncontact nature, active control ability, and feasible multiple degree-of-freedom (DOF). The laser system consists of a laser source fixed on the test table as transmit system, a position sensing detector (PSD) with filter mounted on a stage and a mirror attached to the shaft of the magnetic actuator. The experimental evaluation of switching between encoder and PSD feedback loops, laser locking on stationary and moving PSD within maximal travel range, and laser tracking to smaller reference on stationary PSD, are carried out. This discussion focuses on the rotational axis due to the limited sensor resolution on the five bearing control loops.