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Zhu Q.,Yanshan University | Zhu Q.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province | Xia C.,Yanshan University | Chen W.,Yanshan University | And 2 more authors.
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2015

Aiming at the particle degradation problem of an mobile robot FastSLAM a chaos optimization MPSO based algorithm was proposed. The algorithm incorporated the newest observation information into the prediction of particle, adjusted the proposal distribution of the particles, and the accuracy of prediction of a robot's position was enhanced. The MPSO was solved by a sequential two-step optimization strategy. Firstly, the speed of evolution of particle was improved by the median-oriented acceleration, the particle degradation effectively was overcome, the convergence of the algorithm was improved. Then, focusing on the depletion of the particle, the chaos search algorithm optimization algorithms was introduced to MPSO global optimal position to disperse gathered at local optimum particle swarm to the global optimum location close to broaden the scope of the solution space, thus maintaining the population the diversity of simulation. The experimental results prove that the improved method is correct and feasible. ©, 2015, China Mechanical Engineering Magazine Office. All right reserved. Source


Chen W.,Yanshan University | Chen W.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province | Zhang X.,Yanshan University | Zhu Q.,Yanshan University | And 2 more authors.
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2015

For the problems of slow image processing speed, poor real-time performance and accuracy of feature points extraction and matching in robot localization process, an improved SIFT hierarchical image matching algorithm was proposed based on color moment. Extreme point's detective range was extended, and the gradient directions and magnitude of feature points were calculated by using Sobel operator to improve SIFT performance; besides, the vector angle was taken as a criterion to measure SIFT features' similarity, thus the accuracy and speed of feature points extraction and matching were improved. In image matching process, image sequence was sorted by color moment, then the improved SIFT features were matched with these sorted images precisely. Experimental results show that the proposed algorithm is a real-time and robust method to mobile localization problem: compared with SIFT, the false matching rate of the proposed algorithm is lowered by 9.2%, and the number of feature points are reduced by 20%; hierarchical match improves the speed and accuracy of image matching, for the computation amount of SIFT features is reduced by 60% and the total time consume is reduced by 40%. ©, 2015, China Mechanical Engineering Magazine Office. All right reserved. Source


Zhang Y.-J.,Yanshan University | Zhang Y.-J.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province | Jia W.,Yanshan University | Fu X.-H.,Yanshan University | And 3 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2016

As to fitting the multi-peaks Brillouin scattering spectrum with traditional method, the maximum power point is usually selected as the benchmark while other extreme value points which are less than the maximum power are lost. The fitting curve only has one peak because the multi-peaks Brillouin scattering spectrum is simplified into the highest peak and several small peaks. So it will lead to the loss of useful information. In order to improve the feature extraction accuracy of Brillouin scattering spectrum, a hybrid optimization algorithm named MCDM-PSO-LM algorithm is presented based on MCDM and PSO-LM algorithm. The MCDM algorithm can identify and locate the peaks and valleys of multi-peaks Brillouin scattering spectrum accurately. The PSO-LM hybrid algorithm can realize the curve fitting on every peak and valley, and it can seach the center frequency shift of each peak. The PSO-LM hybrid algorithm can solves these disadvantages, which PSO algorithm premature convergence to local minimum and LM algorithm depends on the initial value problem. It can also combine the global search ability of PSO algorithm and the local search ability of LM algorithm. Compared with traditional algorithms, MCDM-PSO-LM algorithm can ensure the solving speed and accuracy to the optimal value, and the analytical solution will be close to the optimal value sufficiently. So it improves the operation ability. With different signal to noise ratio and linewidth, the results of frequency shift and temperature error show that the MCDM-PSO-LM method can locate every peak and valley of multi-peaks Brillouin scattering spectrum accurately. Thus, it can be used for the feature extraction of multi-peaks Brillouin scattering spectrum. The recognition effect of this method is obviously better than that of traditional algorithms and it can improve the accuracy of information analysis. © 2016, Peking University Press. All right reserved. Source


Chen W.,Yanshan University | Chen W.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province | Yu N.,Yanshan University | Yu N.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province | And 2 more authors.
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2014

We propose a compact photonic crystal Mach-Zehnder interferometer index sensor with a two-dimensional rotated square lattice, based on the photonic crystal self-collimation effect. Using the same background index, the different index of the circular rods has different effective index. The line defected and the air slab waveguide are respectively used as the beam splitter and mirror of the interferometer, and a sensing area is setting on one arm of the interferometer. The index of the circular rods changes with the concentration of the solution filled into the sensing region, thereby affecting the center wavelength of the transmission spectrum, and establishing a mathematical relationship between the solution concentration and the transmission wavelength. Then we carry out a numerical simulation of the concentration measurement of the alcohol solution, the results show that the sensor sensitivity is 250 nm/RIU in the refractive index variation within the scope of 1.33-1.37. Source


Li D.,Yanshan University | Zhang Y.,Yanshan University | Zhang Y.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province | Fu X.,Yanshan University | Fu X.,The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2014

A new method which combines the Simplex code with the average superposition algorithm-S superposition algorithm is proposed . In the condition of the same denoising effect of the two methods, S superposition algorithm can substantially reduce the number of superposition to reduce the time of the signal processing and solve the problem brought by the length of Simplex code. In order to verify the correctness of the S superposition algorithm, create mathematical model of the distributed optical fiber sensing system. Simulation experiment is launched with the mathematical model. The results of the simulation experiment show that the S superposition algorithm can greatly reduce the signal processing time. It proves the correctness and validity of the new method. Source

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