LINEARIZED ULTRASOUND BEAM ALIGNMENT SERVO

摘要

A levitated rotor (340), neutrally buoyed in ultrasound transmission fluid, moves to position and aim an ultrasound transducer in up to five servo-controlled coordinates of position and tilt rotation. Stator drives/sense windings drive the rotor (340) via a rotor magnet and sense coordinates via inductive interactions with a rotor coil. For five-axis control, one set of stator windings controls two-axis lateral translation while a second set controls axial translation plus two-axis tilt rotation. The windings produce a comparatively linear relationship between the five rotor geometric coordinates and the electromagnetic couplings that drive and sense these coordinates. To produce this linearity seamlessly over a wide coordinate range coming close to the windings, each set of windings is divided into overlapping subsets. A two-way drive/sense matrix mapping translates between up to five control coordinates and more than five winding circuits.