Register-Level Digital Twin for a PLC Stepper Card and Stepper Motor for Teaching Purposes using MATLAB Simulink and Stateflow

Abstract

This thesis presents a register-level digital twin of a stepper motor drive designed to facilitate teaching and early verification in situations where hardware is limited. The digital twin models the B&R X20SM1426 controller as a transparent state machine that utilises the same register interface as the actual device. It is paired with a discrete-time stepper motor model that captures the essential behaviours necessary for realistic motion. A script-driven test bench conducts typical motion tasks and fault scenarios, records the responses, and compares them against expected behaviours derived from datasheets and common practice. The work emphasises clarity and accessibility: internal states, status flags, and motion profiles are visible and can be modified, allowing students to safely explore command sequences, Ramp-mode motion, and fault handling. Additionally, the software offers smoother, higher-order trajectory options to illustrate the trade-offs involved in motion quality. Validation involves comparing simulated trends with manufacturer characteristics to ensure the model performs realistically for educational purposes. The result is a compact, classroom-ready platform designed for experimenting with embedded motion control at the register level. It is suitable for demonstrations, assignments, and automated checks of controller logic. The model intentionally simplifies specific physical effects to enhance transparency and speed. The findings indicate possibilities for future improvements, such as more detailed electromagnetic modelling and hardware-in-the-loop evaluation.

Date of Award	2025
Original language	English
Supervisor	Franz Auinger (Supervisor)