Two-layers service middleware for non-smart IoT sensors: case studies on industrial applications

In 2021, more than 5.5 million new devices will be connected to the Internet of things every day. The discovery and access of IoT sensors are difficult to adapt to the growth rate of machines. Especially for non-smart IoT sensors, due to their inability to actively match and lack of self-description, the existing IoT technology is challenging to find and access. This paper provides a two-layers service middleware for non-smart IoT sensors accessing. An edge-side middleware service is proposed to model and discover the non-smart IoT. A server-side IoT middleware service is proposed to encapsulate non-smart IoT sensors into standard web services for downstream applications. Then, the data from non-smart devices are then integrated into a knowledge graph-based database with unified web service APIs to solve the heterogeneity problem. The proposed method is applied to the two industrial projects of "rural sewage treatment automatic station service" and "material digital production line service" to solve the discovery and access of many non-smart IoT devices. This paper provides a novel and feasible technical way to discover and access non-smart IoT devices in two aspects of theoretical research and industrial practice.