Papers by Author: Yan Li

Abstract: In this paper a hybrid algorithm named IPSO-VND is proposed and applied to solving the vehicle routing problem with simultaneous pickup and delivery (VRPSPD). The IPSO-VND algorithm combines two meta-heuristics: Improved Particle Swarm Optimization (IPSO) is used to find a group of excellent solutions, and then the Variable Neighborhood Descent (VND) is implemented to deeply search to achieve the optimal solution around these solutions. During the IPSO procedure, in order to make up for the change of a particle’s position, a velocity component is added to the movement of any particle which has been optimized or made feasible. During the VND procedure, three different neighborhood structures: insertion, swap and cross are successively used. Computational results on the benchmark problems show that our IPSO-VND algorithm is effective.

Abstract: Considering the nonlinear relationship of the joint surface between parts in machine tool assembly, a finite element analysis method based on assembly relationship is proposed. By this method, a finite element model is set up. Based on the analysis of experimental data, the result is close to the actual working conditions, which proves that this analysis method based on the machine tool assemble relationship is feasible and reliable

Abstract: To reduce the noise error existing in the output signal of fiber optic gyroscopes (FOGs) and increase the precision of the FOGs, this paper established a mathematical model of the FOGs output signal, analyzed the error characteristics of the FOGs output signal, put forward a new de-noising arithmetic based on the wavelet transform, soft and hard threshold compromise filtering, threshold values were determined by multi-dimensions recursion arithmetic. Through experiment, it has been already validated that the proposed approach had the competitive performances on visual quality, signal to noise ratio (SNR) and the standard variation, it is effective in eliminating the white noises existing in the output signal of the FOG.

Abstract: In general, production control of digital workshops is a complicated systematical engineering. Because of lacking the methods and means of acquiring the manufacturing data in real time, the traditional production control methods cannot satisfy the real production control requirement of digital workshops. In this paper, we put forward an intelligent control system for digital workshop production. The main contributions include three aspects: Firstly, we introduce and adopt Radio Frequency Identification (RFID) technology as a means to acquire the manufacturing information in real time produced by the bottom-level manufacturing devices. Secondly, we develop the wcPML (workshop control with Physical Markup Language) and utilize it to act as a media to realize the information visualized description and transmission between the top-level control systems and bottom-level manufacturing sites of workshops. Thirdly, we adopt Java Web technology and wireless LAN to build the infrostructure for the intelligent control system for workshop production. Some key enabling technologies for the intelligent control system also are presented and described following with some concluding remarks.

Abstract: The rolling technic of involute spline has many advantages. This method can increase the production efficiency, has no cutting, can improve the metal structure of machining surface to increase the quality of surface and prolong the life of product, so the technic is used extensively in the industry of automobile and tractor. The design model of spline outline is built according to the formative theory of equidistant spiral surface by means of meshing principle of involute spline, roller is manufactured and machining spline is test according to the model. The correction of spline outline is accounted by means of measuring the outline of spline in three-coordinates measuring machine and comparing the measuring data and the data of ideal involute spline. The spline is remachined in corrected roller and ideal spline shape is gotten.