# A Framework for Communicating and Building a Digital Twin Model of the Electric Car
## 1 Introduction
\begin{table}
\begin{tabular}{l l l} \hline
**Category** & **Dimensions** & **Comment** \\ \hline \hline \multirow{6}{*}{Creation time} & A DT was designed in parallel with the product’s design or later in the product life cycle. \\ \cline{2-3}  & Modelled characteristics & Which object behavior is modelled: geometric, kinematic, sensor, control, or system characteristics. \\ \cline{2-3}  & Digital model types & Referring to the types of simulation models, the following are distinguished: \\  & & \(\bullet\) Deterministic and stochastic models. \\  & & \(\bullet\) Static and dynamic models. \\  & & \(\bullet\) Discrete and continuous models. \\ \cline{2-3}  & Model authenticity & How reliable is the digital twin representation compared to the actual product? \\ \cline{2-3}  & Model maintenance & DT’s ability to ensure system validation and accuracy in new circumstances. Some cases require manual adaptation, while others are autonomous. \\ \cline{2-3}  & Modularity & How the architecture of the DT system is designed and whether it integrates more modules. \\  & & \(\bullet\) Unit—low complexity DT system architecture. \\  & & \(\bullet\) System—several units cooperating within a modular system architecture. \\  & & \(\bullet\) System of systems—a set of interconnected systems, services and modules. \\ \hline \multirow{6}{*}{Data} & Data storage & The location where data are stored depends on the size, type, and method of obtaining it local disk, local server, cloud. \\ \cline{2-3}  & Data scope & The scale of data acquisition. Data from a single object, external data from many resources or big data. \\ \cline{2-3}  & Data quality & Matching system requirements. The attributes of data quality are accuracy, completeness, consistency, and uniqueness. \\ \cline{2-3}  & Data sources & DT uses data from physical sensors and measurements but also from simulation and analysis. \\ \cline{2-3}  & Data interpretation & DT’s capabilities to use incoming data. If a DT operates on irregular and unsorted data. \\ \hline \multirow{6}{*}{Control} & Level of cognition & DT is only for monitoring and diagnostic purposes or gives predictive forecasts based on a simulation. \\ \cline{2-3}  & Levels of autonomy & How DT processes decisions: with user support or fully independently, autonomous. \\ \cline{2-3}  & Learning capabilities & Determines whether a machine learning algorithm exists; supervised, semi-supervised, unsupervised, and reinforced. \\ \cline{2-3}  & Types of interaction devices & Method of interacting with DT, starting with keyboard, mouse, display, and touchscreen. It may also include remote control via mobile phones or even cameras for the adaptive assistance system. \\ \cline{2-3}  & Human interaction capabilities & In case of new challenges, DT adapts itself or the output responses are predefined. \\ \cline{2-3}  & & \\ \cline{2-3}  & & \\ \end{tabular}
\end{table} 
Table 1: _Cont._The complexity of Industry 4.0 affects the automotive industry, especially in the simulation aspect [31]. There are many methods for simulating automotive systems, such as the following [32]:  
* Model-in-the-loop (MiL)--a computer-simulated model in an environment, such as Simulink; used for capturing the most important features of the plant (hardware), identifying errors in mathematical equations, and understanding the behavior of a model under specific conditions and finding areas for improvement. * Software-in-the-loop (SiL)--a computer-simulated model and controller model; software simulator instead of real hardware; an essential tool for identifying defects and problems; the software provides input data that is fed into the model. The model then process the input and produces output that is captured and analyzed. Outputs are compared to the expected results to determine whether the model is working correctly. * Processor-in-the-loop (PiL) or FPGA-in-the-loop (FiL)--controller code runs on the built-in processor, testing the processor in the developed control logic and finding faults.