A microprocessor-based system for adaptable calibration and linearization of hall-effect position sensors

The proposed system demonstrates a method that adapts to relatively unpredictable transducer output characteristics and produces a calibrated, linear output. Little a priori knowledge or assumptions concerning the transducer´s characteristics are required. An external reference transducer is used as input to a microcontroller-based signal-processing system that implements a real-time calibration procedure whereby the reference sensor and the Hall sensor measure position in tandem. The unique and variable characteristics of each transducer are converted to an accurate and predictable position measure via a look-up table that is automatically generated during the calibration procedure. An 8031 microcontroller-based prototype was developed for angular sensors and is programmable to maximize resolution for any angular range between 0 and 360°. The proposed system is discussed with regard to applications in transducer manufacturing and biomedical engineering.