Development and Metrological Evaluation of a Low-Cost Stepper Motor Positioning System with Magnetic Feedback: Analysis of Deterministic Error Mechanisms

Modern industrial automation systems and intelligent electric drives require precise and reliable methods for position measurement and actuator operational parameter diagnostics. Cost-effective systems that enable real-time monitoring of drive operation and analysis of errors affecting positioning accuracy are particularly crucial in this domain. This article presents the design and validation of a custom measurement and control platform for precise positioning of a stepper motor shaft using an AS5600 absolute magnetic encoder as a feedback element. The proposed architecture integrates the sensing hardware, controller based on the ESP32 microcontroller and dedicated software enabling the acquisition, analysis, and diagnostics of drive operating parameters. A comprehensive metrological evaluation of the sensor system was conducted, assessing measurement resolution, position accuracy, repeatability and the effect of the mechanical assembly tolerances on error generation. Experimental tests revealed the occurrence of systematic deviations resulting primarily from misalignment of mechanical components and non-ideal positioning of the magnet relative to the sensor. The results demonstrate that these systematic errors can be effectively compensated for using look-up tables (LUTs) or Fourier-series harmonic modeling. The developed platform offers a blueprint for implementing advanced, low-cost measurement, and control units in high-precision drives. Furthermore, the findings show that detailed sensor characterization and error source identification enable significant control quality improvements using budget-friendly components. Overall, this approach highlights the vital role of integrating data acquisition, analysis, and digital error correction to enhance accuracy in modern electric drives.