Brushless permanent magnet motor position estimator

A nonlinear rotor position estimation algorithm for permanent magnet brushless motors is presented. The algorithm is based on an example of a new concept in rotor position estimation. Innovations in this estimator are in its application of the same algorithm at both stand still and while the motor is rotating, its ability to track rotor position without imposing any power signal requirements on the motor controller and the dispensation with the need to make any kind of load torque estimation. The algorithm estimates the current rotor position from the current motor terminal voltages, currents and rates of change of currents. At stand still the algorithm relies on being able to detect in terminal measurements, changes in the magnetic saturation pattern inside the motor