A setup routine measures the motor's characteristics and determines all of the required parameters automatically. Depending on the type of motor, speed and positioning information is obtained at a speed of 25–250 rpm with an accuracy said to be comparable to that of a conventional optical encoder with 500 or 1,000 increments.
According to Nanotec, this allows a level of control to be achieved as good as – and with the same torque as – a motor controlled using an encoder. To operate at lower speeds and for positioning purposes, it is possible to switch automatically to open-loop mode.
Nanotec says that its sensorless technology allows stepper motors to be operated like servomotors
The company says that the new closed-loop mode is suitable for applications where traditional closed-loop set-ups with encoders cannot be used due to cost constraints. The new sensorless control system is available as a firmware update for Nanotec’s N and C series controllers.
