Our software does away with the need for position sensors (encoders and resolvers) by calculating the rotor position from measurement of current and voltage.
At low speed, the problem becomes even harder, as there is no winding emf, so we:
The winding inductance is hard to measure when there is an emf present so it is only used for low speed.
To achieve low torque ripple we start with the motor design link.
Our sensorless control forces us to push the boundaries of adaptive control, by having no sensors we need to learn the characteristics of the motor during operation. The inverter is continuously monitoring the motor and the load.