On October 31, five days before the first China International Import Expo (CIIE), China International Import Expo Bureau released a Wechat miniprogram of China International Import Expo Navigation Service in collaboration with Tencent company. The Floor Plan module in the miniprogram is supported by the positioning system for navigation which was developed by Professor LIU Erwu's team from the School of Electronics and Information Engineering, Tongji University. The system will provide digital navigation service to exhibitors during the CIIE. This is the world's first huge indoor positioning system for navigation. Inside the exhibition hall, the system can accurately lead you to the exact location you want to visit.

Professor Liu's team independently developed the indoor positioning technology of DWELT (Dynamic Weighted Evolution for Location Tracking) which targeted positioning without satellite and wireless signals. DWELT integrated mobile phone sensors, geomagnetic, wireless and visual signals by means of data fusion and machine learning. In this way, high-precision positioning can be achieved without extensive deployment of infrastructure and hardware. DWELT meets the needs of precise positioning for navigation at complex scenarios such as exhibitions, stadiums, shopping malls and underground parking lots. DWELT represents an internationally leading solution for indoor positioning on mobile phones characterized by its high precision, low cost, low latency, full sample, simple deployment and easy expansion. It won the championship in Microsoft International Indoor Localization Competition in addition to a silver medal in innovation at the China International Industry Fair.