In order to explore the design strategy of participatory design approach in the design of external human-machine interface (eHMI), this paper at the theoretical level researches the relevant literature and typical interfaces of eHMIs, and sorts out the basic concepts of explicit human-vehicle interaction features theory. Through the user participatory design method, we summarized the key design points of the eHMI and produced a design prototype, and optimized the prototype according to the participatory design experimental results and actual needs to obtain a design solution. The design was tested and evaluated at the practical level, and a strategy for user participation in the design of the external human-machine interface was concluded. The results show that the participatory design approach can improve the usability and acceptance of eHMIs, reduce the cognitive differences in the presentation of interface content, and provide a reference for the design of out-of-vehicle HCI in future work.

Diet management has become a common concern in daily life. Most of the current related designs provide accurate calorie estimates and personalized diet recommendations, which does not touch the core of management – how to make this behavior active and sustainable. This study introduces the concept of Positive Design, constructs a three-step design path which is applied in practice, aiming to give long-term happiness to diet management and promote users’ active adherence. The vital step is to invite target users and designers to join in collaborative work, identify and filter eight conflict dilemmas which are worthy of study. Positive design is a new theoretical perspective based on positive psychology. The final scheme produced in this paper aims to explore the application of this method in diet management design, and also provide a certain reference for subsequent research.

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