Yu Qifeng's main research work

1. Since 1980s, Yu Qifeng has been devoted to the analysis and research of fringe images in optical experimental mechanics, and initiated and developed a series of theories and methods for processing optical interference fringe patterns, such as spin filtering, isoline window filtering and correlation method, which can filter out all kinds of noises (including ESPI) of fringe patterns and keep fringe phase integrity. In the integration of optical experimental mechanics with optical engineering, photogrammetry, computer vision and other disciplines, the application field of photogrammetry, a new international interdisciplinary subject, has been opened up, and distinctive theoretical research results and application results have been obtained.

2. Combining the optical measurement conditions and target characteristics of the shooting range test base, he invented a variety of three-dimensional attitude measurement methods for shooting range targets, and developed a digital image analysis system for shooting range optical measurement, which realized the technical leap from three-degree-of-freedom position parameter measurement to six-degree-of-freedom position and attitude parameter measurement in China without adding external measurement equipment. This achievement has been applied to all test shooting ranges with optical measurement requirements in our army and has become the main force of shooting range interpretation equipment. This achievement was identified as "the new change of domestic shooting range interpretation system in the past 40 years" and "fruitful pioneering work was carried out in the field of optical film interpretation in digital shooting range, and there was a major breakthrough and innovation in the precise measurement of optical images."

3. I have been engaged in the technical and scientific research of large-scale structural deformation measurement and large-scale motion measurement in experimental mechanics for a long time, and developed the theory and method of camera measurement. In the aspect of measuring moving targets with fixed-point cameras, the key technologies of three-dimensional attitude measurement and automatic real-time three-dimensional motion measurement of shooting range targets are overcome. In the aspect of measuring moving target with moving camera, the theory and method of measuring three-dimensional motion of point target with moving camera, blind multi-point dynamic deformation monitoring and dynamic calibration of unstable measurement platform are established. In the static scene measurement of moving camera (self-motion measurement of camera platform), a series of new methods of aircraft visual navigation are proposed, which improve the accuracy and adaptability of scene matching and target recognition. In the aspect of static deformation measurement, the theory and method of lossless phase denoising of interference fringe pattern and systematic error elimination of fringe center line are put forward. The research results have been successfully applied to manned space flight and national defense.