Toward Reproducibility of Digital Twin Research: Exemplified with the PiCar-X

Digital twins are becoming increasingly relevant in the Industrial Internet of Things and Industry 4.0, enhancing the capabilities and quality of various applications. However, the concept of \dts lacks a unified definition and faces validation challenges, partly due to the scarcity of reproducible modules or source codes in existing studies. While many applications are described in case studies, they often lack detailed, re-usable specifications for researchers and engineers. In previous research, we defined and formalized the \dt concept. This paper presents a reproducible laboratory experiment that demonstrates various \dt concepts. Our formalized concept encompasses the \pt, the digital model, the digital template, the digital thread, the digital shadow, the \dt, and the \dtp. We illustrate this series of concepts by using a PiCar-X, showcasing the progression from a \pt to its \dtp. The entire code base is published as open source, and for each concept, Docker-compose files are provided to facilitate independent exploration, understanding, and extension.