Beijing Aerospace Times Optical electronic Technology Co.
Beijing Aerospace Times Optical electronic Technology Co.
Zhang F.,Beijing Aerospace Times Optical Electronic Technology Co. |
Huang J.-X.,Beijing Aerospace Times Optical Electronic Technology Co. |
Wang S.-B.,Beijing Aerospace Times Optical Electronic Technology Co.
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2016
To improve the precision of fiber optic gyroscope (FOG) in high dynamic environment, the angular acceleration must be accurately identified to make effective compensation. In view that the FOG angular acceleration obtained by direct differentially processing the FOG angle velocity information has relatively large errors, the angular acceleration information is divided into the linear part and the nonlinear part. The linear part uses savitzky-golay algorithm to carry out least square fitting, while the nonlinear part uses RBF neural network (RBF NN) method to carry out fitting. This method has more strong adaptability and has better fitting effect because it can more truly reflect the real physical process. Finally, simulations are made to test and compensate the measurement errors of FOG angular velocity under high dynamic environment, which verifies that the algorithm is correct and effective, and the identification accuracy of the angular acceleration is improved by two orders of magnitude than that of the direct differential method, showing that the proposed method can effectively compensate the FOG measurement errors under high dynamic environment. © 2016, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.
Dong P.,North China Electrical Power University |
Huang S.,North China Electrical Power University |
Li Z.,China Electric Power Research Institute |
Qiao X.,Beijing Aerospace Times Optical electronic Technology Co.
Gaodianya Jishu/High Voltage Engineering | Year: 2016
UHVDC hierarchical connection mode is a new structure in which the ±800 kV UHVDC system access to the 1 000 kV UHV AC system for the first time. In order to decide the overvoltage level of converter bus, we researched the temporary power frequency overvoltage and switching overvoltage of converter bus in two kinds of UHVDC hierarchical connection modes. The reason of the highest overvoltage is analyzed. The highest overvoltage and overvoltage conditions are presented. For Taizhou station in scheme1, the phase to ground overvoltage is 1.54, and the phase to phase overvoltage is 2.71. For Linyi station in scheme2, the phase to ground overvoltage is 1.57, and the phase to phase overvoltage is 2.97. Measures to reduce the converter bus overvoltage are put forward. This study provides a basis for the selection of the air gap distance and insulation of the 1 000 kV UHVDC converter station. © 2016, High Voltage Engineering Editorial Department of CEPRI. All right reserved.
Liu Y.,Beijing Aerospace Times Optical Electronic Technology Co. |
Song S.,HIT Special Robot Co. |
Wang C.,Beihang University
International Journal of Advanced Robotic Systems | Year: 2017
In this article, the design on the shock absorber of the lunar probe soft landing can be considered as a single- or multi-objective optimization problem. Here, the optimized objective parameters include the maximum toppling stability, defined as Dmin, and the minimum stroke of primary strut energy absorption, SPmax . However, the two optimized variables are conflict objectives. In order to give an overall consideration about the multi-performances of landing, the multi-objective optimization strategy is proposed and nondominated sorting genetic algorithm II is employed to find the best decision parameters of the shock absorber design. To conduct the optimizations, firstly, the worst landing cases and safety boundaries for both toppling and primary strut energy absorptions are obtained by the computer simulation experiments. Both single- and multi-objective optimizations are then implemented aiming to expand the stability boundary. The results show that the landing stability is effectively improved after optimizations, and also demonstrate that the multi-objective optimization strategy is superior to that of the single-objective optimization. © The Author(s) 2017.
Liu H.,Beijing Aerospace Times Optical electronic Technology Co. |
Wang W.,Beijing Aerospace Times Optical electronic Technology Co. |
Li X.,Beijing Aerospace Times Optical electronic Technology Co.
2012 IEEE International Conference on Robotics and Biomimetics, ROBIO 2012 - Conference Digest | Year: 2012
A novel defect segmentation method, which utilizes both the Gaussian Mixture Model (GMM) and the Graph Cut Model (GCM), is presented to solve the defect segmentation problem of the hot image for the fiber splicing process on our industrial robot system. Since the fiber has a plastic surface, the LED lamp will create a highlight region in the fiber center when the camera collects the image data during the splicing process. Unfortunately, this highlight region always submerges the defect region. To solve this problem, both the image samples of normal mode and those of the defect mode are employed as the prior information to improve the segmentation performance. When implementing our method, first the GMM and the image samples of normal mode are used to build the statistic illumination model of the spliced fiber. The log histogram is tuned by the GMM components. Once the GMM is built, it can be utilized to restrain the highlight of the defect images. Then the GCM and the image samples of defect mode can be employed to segment the defect region and analyze their region features. Many simulation results have proved the effect of our proposed method. © 2012 IEEE.
Ding M.,University of Southampton |
Wang P.,Dublin Institute of Technology |
Wang J.,Beijing Aerospace Times Optical Electronic Technology Co. |
Brambilla G.,University of Southampton
IEEE Photonics Technology Letters | Year: 2014
A compact singlemode-multimode-singlemode fiber tip (SMST) refractive index sensor is demonstrated. Focused ion beam milling is exploited to have a clean fiber tip cut which is then coated by a layer of gold to increase reflection. An average sensitivity of 265 nm/RIU and a resolvable index change of 3.77 × 10-5 are obtained experimentally with a ∼ 2.94 μm diameter SMST. Because of its compactness, ease of fabrication, linear response, good sensitivity, easy connectivity to other in-fiber optical components, and low cost, this refractometer could find various applications in chemical and biological sensing. © 2013 IEEE.
Liu W.D.,South China University of Technology |
Sun Y.,Beijing Aerospace times optical electronic technology Co.
Applied Mechanics and Materials | Year: 2014
Ideal geometry is mainly represented by several parameters in traditional CAD system. Based on these parameters, ideal geometry can be dynamically constructed to build the entire CAD entity; however, the modeling of variated geometry by parameters is not included, and parametric representation for variated geometry is introduced in this paper; sets of parameters for different types of geometry variation are discussed. Based on parametric representation for variated geometry, the translation and orientation error of part that affected by the variation of geometry is calculated, the process for converting geometry error to parametric part location error is introduced. © (2014) Trans Tech Publications, Switzerland.
Wang W.,Beijing Aerospace Times Optical Electronic Technology Co. |
Xiang Z.,Beijing Aerospace Times Optical Electronic Technology Co. |
Xing H.,Beijing Aerospace Times Optical Electronic Technology Co.
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2012
To solve the problems of thermally induced nonreciprocal phase-shift in fiber coil, a three-dimensional temperature transient thermal model was established through thermal analysis. Under the actual working environment of fiber optic gyroscope (FOG), the temperature transient response model was used to analyze the thermally induced nonreciprocity caused by three-dimensional temperature gradient. Numerical simulations were carried out on the quadruple winding pattern fiber coil to obtain the velocity errors caused by temperature gradient. The calculation results from the FOG experimental data in incubator show that the maximum difference between the tested velocity error and the model calculated data is 0.48 (°)/h, which verify the effectiveness of three-dimensional temperature transient response fiber coil model. This model could provide reference for the design of fiber coil thermal structure parameters, hence reduce the Shupe error of fiber coil and improve the FOG's temperature performance.
Liu F.-M.,Beijing Aerospace Times Optical electronic Technology Co. |
Huang T.,Beijing Aerospace Times Optical electronic Technology Co. |
Li R.-L.,Beijing Aerospace Times Optical electronic Technology Co. |
Zheng G.-K.,Beijing Aerospace Times Optical electronic Technology Co.
Guangzi Xuebao/Acta Photonica Sinica | Year: 2011
Effects of external stress applied to polarization-maintaining (PM) fiber pigtail of a Y-branch multi-functional integrated optical device on extinction ratio as well as its temperature stability are researched. Based on the analysis of stress on the fiber, expression of extinction ratio as a function of the magnitude and direction of the stress is deduced, and the temperature stability of extinction ratio is discussed. Results show that the external stress is the main factor which affects extinction ratio and its stability. When the direction of stress is at an angle from the birefringent axes of a free PM fiber, the maximum extinction ratio achieves during fiber-chip coupling is smaller than that of a free fiber. As a result, the polarizing direction of the chip and the slow axis of the fiber will be mis-aligned. The change of the stress in magnitude and direction caused by temperature results in the fluctuation of the extinction ratio. While the stress is along the birefringent axes of the fiber, it has no effect on extinction ratio, and the polarizing direction of the chip and the slow axis of the fiber can be precisely aligned. Fiber pigtails fixed with a V-groove and with a U-groove are analyzed in comparison, and test results show that a fixing block with a V-groove can improve extinction ratio and its stability effectively.
Feng W.-S.,Beijing Aerospace Times Optical Electronic Technology Co. |
Wang X.-F.,Beijing Aerospace Times Optical Electronic Technology Co. |
Wang W.,Beijing Aerospace Times Optical Electronic Technology Co.
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2011
By studying the turns' difference in each layer of fiber coil, the improvement of FOG's temperature performance is realized. A new turn-by-turn quantization Shupe bias error model is established. Comparing Mohr temperature distribution models of fiber coils, an interpolation model based on the known temperature boundary condition is proposed. The quantization Shupe bias error models are established whose number of turns of the two outermost layers is different from other layers. Based on the temperature distribution models mentioned above, the effects of three kinds of corresponding fiber coils on the temperature performance of FOG are simulated under the radial temperature gradient respectively. A measuring system is designed to verify the effect. Experiment results show that the Shupe bias errors of the two outermost layers of fiber coils is reduced at least 50% when with half turns, and this agrees with the results of theoretical study.
BEIJING Aerospace TIMES OPTICAL ELECTRONIC TECHNOLOGY CO. | Date: 2011-10-31
An electro-optic effect based optical voltage transformer comprises an optical voltage sensor head and an electrical unit, wherein the electrical unit comprises an optical closed-loop feedback control unit and a signal processing unit, the optical closed-loop feedback control unit is connected to the optical voltage sensor head and the optical voltage sensor head is connected to the signal processing unit. In this invention, the light source output power is more stable, the light source center wavelength drift is effectively controlled and the output power coastdown caused by light source aging is prevented; the optical power fluctuation of the optical polarization caused by factors such as temperature, optical fiber vibration, etc., is eliminated, which is conductive to stability and reliability of the optical system; the accuracy of data is improved.