Magnetic Linear Encoder Based on Fuzzy Transition Algorithm

In the research into linear displacement sensors, the main research targets are optical grating and magnetic grating-based displacement sensors. However, magnetic grating and optical grating techniques are horizontal measurement methods, which basically require a sliding substrate, a read head, and other components. The resulting magnetic grating or optical grating-based displacement sensors are large in size and cannot realize displacement measurements in small space or vertical measurement scenarios. In this article, a novel and highly accurate linear displacement sensor is designed for use in small space and vertical measurements that uses a completely different structure to conventional magnetic grating or optical grating-based displacement sensors. The proposed magnetic linear displacement sensor consists of two components: a moving shaft with nested magnets and a printed circuit board (PCB) that does not need a moving substrate or a sliding guide. The proposed sensor offers a simple structure, small size, high measurement stability, and high environmental adaptability. The sensor has a completely new structure, and no similar structural design has been reported in the current literature. A permanent magnet ring, an anti-oscillation interference structure, and a system circuit are designed in this article, and the possible oscillating interference, deterministic error, and random interference error characteristics of the sensor are analyzed. A linear displacement sensor decoding algorithm based on fuzzy transitions is designed based on the anti-oscillation structure: the corresponding anti-interference algorithm is added to it, and the effectiveness of the fuzzy transition decoding algorithm is then verified. Finally, an experimental platform is designed for nonlinear error calibration and swing error validation, and the performance specifications of the proposed displacement sensor are verified using this platform. The effect of oscillation error suppression is verified via oscillation experiments that confirm the robustness of the magnetic displacement sensor.