Papers by Author: Wei Liu

Abstract: Subdivision technology provides a convenient way to represent smooth surfaces of arbitrary topological structures. The technology is now widely applied in character animation and computer graphics. However, it meets challenges if to be employed in machining. This paper focuses on the problems of surface subdivision in machining applications and the solutions for these problems. The work includes two parts. First, an algorithm of Loop subdivision that can keep sharp surface features is presented. And second, a cross-section method is employed to obtain the NC tool path of the divided surface. The NC tool path of the refined model is verified with the MasterCAM software. The research is valuable for the improvement of the subdivision scheme commonly used in CAD/CAM system.

Abstract: The linear quadratic Gaussian Optimal control of a two-stage HFAC inverter system has been investigated in this paper. The uncertainty model of the high frequency resonant inverter is developed and analyzed with the input line and load variations taken into design considerations. The proposed control scheme has the advantages of fast response for both input line and load perturbations. It also ensures a wide range of system stability and guarantees robustness of the power converter. Both simulations and experimental results are provided to verify with the theoretical analysis through an experimental prototype with an output power of 500-W operating at 10 KHz and an output voltage of 24 V (peak value).