The shift of meters from having needles and numerical displays to larger displays has been driven by integrating multiple sources of information using advanced driver assistance systems and entertainment for autonomous driving. Table terminals are being used as in-vehicle meters, requiring complex displays and significant time for building and validating systems that provide drivers with crucial driving information. However, the development of meter systems is hampered by a shortage of software human resources. A framework incorporating a display design tool specializing in tablet terminal applications using model-based development methods is proposed. The framework combines design tools, model-based methods, and image-processing techniques to create a codeless system that does not require specialized software engineers to perform automated verifications. Display design tools, such as Kanzi, Qt, Altia, and CGI-Studio are available for developing tablet applications. Furthermore, they are now being used for meters and navigation system designs. These tools allow designers to intuitively create screens, specify display positions, and animate warning messages and other image components, such as signs. However, changing the display positions of display components partially or completely is time-consuming and difficult to manage due to design changes. Additionally, over 30 languages must be supported depending on the destination, making manual data management by human operators significantly complex. Qt has distinctive features among the aforementioned tools. After intuitively creating a screen, attribute data, such as display positions, were converted into Qt Modeling Language (QML)—a proprietary language similar to JavaScript. The display components described in the QML were animated and controlled by C++ code. Therefore, advanced coding techniques based on object orientation are required to master Qt. However, the vehicle software industry lacks human resources. Notably, Qt can simultaneously manage parts using code, prevent human errors in placement, and support over 30 languages logically and in a nonspecialized manner by creating derivations from object-oriented base classes. However, MATLAB/Simulink is commonly used as a standard model-based design tool in vehicle design, including mechanical and software design of meters. MATLAB/Simulink does not require special code; it can be designed intuitively using block diagrams, making it suitable for engineers without special software skills. However, the behavior of the designed model can only be studied using a simple graphical representation. Therefore, the results must be properly visualized. For example, a model-based designer can conclude from the graph that two warning signals are detected simultaneously by modeling the meter logic. However, determining the effectiveness of warning signals is impossible without their display. Screen design in Qt and logic design in MATLAB/Simulink have been performed separately and in combination. Hardware becomes expensive when each is implemented in a separate ECU. This study developed a framework based on object orientation using a base class that can be commonly used on Qt, and each logic inherited this base class. The logic was automatically coded and embedded after checking the behavior of the model in MATLAB/Simulink, eliminating the need for the logic designer to write C++ code. This allows a designer to concentrate on the design and visually inspect whether the logic is correct on the Qt screen. Furthermore, the design efficiency was improved because logic and screen design can be performed on a single PC, and logic and screen software can be implemented on a single ECU. However, a system was introduced to extract the characteristic points of the images and automatically warn the user for automatic evaluation of multilingual images mass-produced by code. Moreover, this system automatically evaluates whether design changes, such as changes in display position, have been correctly implemented, improving development efficiency. Although Qt's function of an automatic horizontal alignment of characters without understanding the meaning of multilingual characters is effective, it does not guarantee correct display. When comparing the correct display on a PC with the ECU display results, even if they are the same 16-bit color, a simple comparison cannot be made. A new system was introduced to extract the characteristic points of the images and automatically warn the user for automatic evaluation of multilingual images mass-produced by code. Moreover, this system automatically evaluates whether design changes, such as changes in display position, have been correctly implemented, improving development efficiency.

Prof. Dr. Masatoshi Arai, Technology officer/Professor, Marelli Corporation/Saitama University