Generation of Absolute Patterns for Magnetic Encoders of Arbitrary Size With De Bruijn Sequences
Kai-Yang Peng, Jen-Yuan James Chang · IEEE Sensors Letters · 2024
In this letter, we propose a magnetic encoding method utilizing De Bruijn sequences for absolute encoding. By integrating a single-dimensional array of Hall-effect sensors, a dual-track absolute positioning system was successfully developed and validated. The system leverages the Eulerian circuit algorithm to ensure the nonrepetitive nature of subsequences, fully exploiting variable symbols and subarray length characteristics within the sequence, thereby enabling arbitrary cyclic encoding lengths. This design overcomes the constraints imposed by commercially available products with fixed encoder dimensions. The feasibility of the system was validated through a specific magnetization process, resulting in a dual-track magnetic scale coupled with custom-made arrayed sensing elements and firmware signal integration. This design not only ensures high precision in positioning but also offers universality and adaptability of the generation of absolute patterns for quasi-absolute magnetic encoders of any size, making them applicable to diverse applications.