Sensors for drive systems

In the area of drives and motion control sensors are key components and determine the quality of the complete system. Therefore, design engineers should have a thorough knowledge of the properties and characteristics of each sensor type. This tutorial deals with the sensors for current, position and acceleration as they are the most important control components in drive systems. In a systematical way, their principles of working, their properties and limitations as well as the necessary interfaces and signal processing are presented. Accuracy and resolution of the sensors are important issues in the design and are analyzed in the context of the signal processing of each variable. An overview of the state of the art of sensorless (i. e. encoderless) schemes and their advantages and disadvantages with reference to the actual industrial requirements is given. The two main solutions, the fundamental model approach and the signal injection solution are explained and compared.