Awardees of the 48th International Exhibition of Inventions Geneva have been announced. Research teams from Tsinghua University won a total of 40 awards with a record number of gold prizes. A de-scattering computational imaging system for intelligent surveillance from the research team of CHENG Xuemin and HAO Qun from SIGS was awarded gold. LI Xinghui’s team from SIGS won a silver prize for its invention, an absolute two-DOF grating encoder.
De-scattering computational imaging system for intelligent surveillance
Concept drawings (top) and prototype (bottom) of the team’s invention
The gold-prize-winning invention “De-scattering computational imaging system for intelligent surveillance” aims mainly to achieve video monitoring for large field-of-view spaces in all-weather and 24-hour conditions.
In recent years, anti-scattering vision has become a hot topic in the field of optical imaging. When carrying out outdoor visual perceptions in extreme weather and broad vision, the medium’s composition and dynamic process of the air light field lead to poor visibility, thus the demands for real-time and high-definition imaging tasks are difficult to meet. Addressing these issues, the team has proposed a computational imaging mechanism based on spatial light field coding and temporalized echo detection and developed an imaging camera system that realizes specific information perception of interested targets under strong scattering conditions.
The team led by Associate Research Professor CHENG Xuemin and Adjunct Professor HAO Qun has long been engaged in research work on design, integration, and field applications of opto-mechanical-electrical systems, novel optoelectronic imaging sensing technologies, and intelligent processing of visual information. This project is expected to be applied in monitoring tasks of community security, urban traffic, airports, and port operations. It can also aid in the development of new visual perception scenarios for underwater research. The members of this project also include master’s students, YUE Junbai and ZHANG Weiqiang.
Some members of the project team
An absolute two-DOF grating encoder
Principle of absolute two-DOF grating encoder
Nowadays, precision positioning technology is widely used in advanced manufacturing fields, which directly affects the manufacturing accuracy, processing accuracy, and imaging accuracy of the equipment. At present, there is an urgent need for ultra-precision positioning systems with resolution and accuracy reaching the nanometer level. In addition, the system should be able to simultaneously measure absolute displacement in the X- and Y- directions to eliminate error accumulation.
The award-winning invention, “an absolute two-DOF grating encoder,” optimizes and solves the aforementioned problems. The invention from the team led by Associate Professor LI Xinghui consists of an absolute position codes cross-correlation module and a grating interference measurement module. The system adopts a two-dimensional grating made by interference lithography and proximity lithography technology, which can simultaneously encode incremental displacement and absolute position. Afterward, the position information of the grating is obtained through a precisely designed optical reading head. According to the experiment, the incremental displacement resolution of the system is 1 nm, while the positioning accuracy of the absolute position is 9 nm. Additionally, the experiment verifies that the absolute code channel has no interference with incremental encoding.
The absolute two-DOF grating encoder will provide an effective solution for precision positioning problems in advanced manufacturing fields.
Project team
This project was undertaken by Associate Professor LI Xinghui, Associate Research Professor ZHOU Qian, Associate Research Professor NI Kai, Research Professor WANG Xiaohao, and students ZHU Junhao, WANG Shengtong, WANG Huanhuan, and SHI Yaping.
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The International Exhibition of Inventions of Geneva was founded in 1973 and is held annually (except 2020). To date, a total of 48 exhibitions and two online special editions have been successfully held.
The event is jointly hosted and organized by the Swiss Federal Government, the governments of the canton and city of Geneva, and the World Intellectual Property Organization. This annual exhibition is one of the oldest, largest, and most well-known invention exhibitions around the world.
Source: Institute of Data and Information
Written by Yue Junbai and Zhu Junhao
Edited by Alena Shish & Yuan Yang
