A systematic review of global research on natural user interface for smart home system

The smart home system (SHS) equipped with intelligent sensors and actuators aims at providing seamless services for users. The natural user interface (NUI) enables intuitive interaction between users and the SHS, significantly lowering the barrier to entry and enhancing user experience. However, a comprehensive evaluation of research on NUI for the SHS to provide a valuable synthesis of existing research and informing future research directions remains unavailable. This study attempts to address this gap by systematically evaluating 1979 relevant journal and conference articles from the Web of Science Core Collection and Scopus, and those articles with a weak connection to the topic and poor data integrity were excluded. Finally, 1330 articles were chosen to for analysis in terms of contributions, critical papers, co-occurrence, and clustering using scientometric techniques. It was revealed that, with the help of advancing technologies, the research field of NUI aims to enrich the variety of interactive device types, improve the accuracy of interpreting and responding to user behavior, and optimize the compatibility with diverse user demographics. Besides, a conceptual framework summarizing typical types of NUI for the SHS was proposed, and strengths and weaknesses of each NUI were discussed for investigating specific future directions. Furthermore, four general research directions (strategies for promoting effective multimodal NUI, adoption of artificial intelligence for better performance, exploration of mixed reality applications in the SHS, and standardization of protocols in the smart home ecosystem) were also identified for academics and practitioners in their future research and practice.