Number of Magnetic Poles and Sensors in an Absolute Magnetic Encoder Using Eccentric Structures

With the recent technological innovations in various fields, such as the internet of things and artificial intelligence, our lives have been integrated with robots. Therefore, robots are required to cooperatively operate in the same space as humans. Robots can effectively be controlled depending on the accuracy of the sensors that acquire information regarding the control target. By applying an eccentric structure to a magnetic encoder, the authors developed an absolute angle sensor with a simple configuration and high accuracy. Magnetic encoders can achieve a high resolution by increasing the number of magnetic poles of the magnet. However, the number of sensors used is proportional to the number of magnetic poles of the magnet. In this paper, we proposed a method for calculating the angle by reducing the number of sensors via a table reference. The proposed method achieves absolute angles with the same accuracy as the conventional method.