Beijing Aerospace Times Optical electronic Technology Co.

Beijing, China

Beijing Aerospace Times Optical electronic Technology Co.

Beijing, China

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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.


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. | Wang G.,Beijing Aerospace Times Optical electronic Technology Co.
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2012

In order to remove the fractal noise of fiber optic gyroscope signal, a method of full frequency-domain multi scale wavelet threshold denoising was proposed. Based on the differential form of fractal noise of fiber optic gyroscope signal, the relation between fractal noise and white gaussian noise was revealed. Combing with the high order vanishing moments of wavelet function, decorrelation of fractal noise was achieved in the wavelet domain. When fractal signal was decomposed by wavelet with high-order vanishing moments, the decomposed signal was similar to white gaussian noise and apt to be removed through threshold processing. In addition, according to the wide-band characteristic of the whitened fiber optic gyroscope signal, noise was eliminated through threshold processing to approximation coefficients and detail coefficients. Experiments of fiber optic gyroscope signal denoising demonstrated that the proposed method of better than the classic wavelet threshold deonising, kalman filtering and moving average.


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

A transfer alignment method for reentry spacecraft in view of the space environment's particularity is proposed to serve the need of rapid and precise transfer alignment. The state and measurement equations of the fiber optic gyroscope inertial measurement unit (FOG IMU) are established, and by using the output attitude difference between the outputs of FOG IMU and star sensor, a transfer alignment algorithm is achieved. Since only using UKF has the problems of filtering instability, and only using PF has the problems of particle degradation, an algorithm based on unscented particle filter (UPF) method is presented on account of the nonlinear feature of the state and measurement equations. Simulations are made by using a satellite tool kit (STK) tool to simulate the spacecraft its operations on-orbit, which show that, compared with its traditional method, the misalignment estimation can converge to 0.6 arcmin within 3 s, the estimation accuracy is increased by 30%, and convergence time is shorten by 70%. © 2016, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.


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.


Patent
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.

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