Six Degrees of Freedom Position Sensor

A position sensor with six degrees of freedom (DoF) measurement capability may be used for position sensing of the rotor in a bearingless slice motor to enable active control The sensor is designed to fit entirely under the rotor and operates by accessing the rotor bottom surface only, enabling packaging of the pump on the top of the rotor. The sensor has two parts: both operate using eddy currents. One of these parts measures the two radial DoF of the rotor. The other part measures the axial, angular rotation and tip/tilt DoF. The sensor utilizes a conductive target fixed to the underside of the rotor. The design and fabrication of the sensor along with the signal processing methods are described.