POSITION CONTROLLED DRIVE MECHANISM

摘要

A position controlled drive mechanism including an electric motor, an encoder associated with the rotatable shaft of the electric motor and a controller connected to both the electric motor and the encoder is described herein. The controller includes at least two of the following modes of operation in which the controller is configured as to: a) control the electric motor to rotate the rotatable shaft to a selected position; b) control the electric motor to maintain a current position; c) control the electric motor to rotate the rotatable shaft in a selected direction until an external object hinders the rotation of the rotatable shaft; and d) control the electric motor so as to assist an externally initiated rotation movement of the rotatable shaft detected by the encoder.