Dynamic sensor calibration: A comparative study of a Hall effect sensor and an incremental encoder for measuring shaft rotational position

Abstract

The following work investigates a cost efficient method of measuring shaft rotational position. The proposed sensor configuration consists of a magnet and a Hall effect sensor. When compared to the alternative (an optical encoder), this approach has several advantages including cost, and durability. The puck shaped magnet was placed on the end of a rotating shaft and generated a magnet field oriented transverse to the shaft axis. The Hall effect sensor was placed in a stationary holder co-axially aligned with the shaft and slightly offset, in the axial direction, from the magnet. The sensor output was compared to a high accuracy incremental encoder, which is the industry standard technique. The proposed sensor was tested for its ability to record shaft rotational speed under a variety of test conditions, including; various constant speeds, varying speeds, magnet size, sensor to magnet lateral distance, and various obstructions between the magnet and the sensor (termed readability). The sensor provided excellent measurement results, under all test conditions and compared well to the incremental optical encoder.