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Li L.,Harbin Engineering University | Li L.,CAS Academy of Opto Electronics | Yang W.,Harbin Engineering University | Yang W.,Huazhong Institute of Electro Optics | And 2 more authors.
Chinese Control Conference, CCC | Year: 2015

Carrier-Smoothed-Code (CSC) can effectively suppress the multipath effect and receiver noise in the code-based differential positioning, which is widely adopted by the Ground Based Augmentation System (GBAS). However, the accuracy of smoothed code can be degraded significantly by the Code-Carrier-Divergence (CCD) effect. The CCD monitoring technology of for BeiDou Satellite System (BDS) is still under developing. This paper analyzed and compared two methods of CCD monitoring in GPS and BDS, respectively. Based on the CCD monitoring results, it was found that the tow-order linear invariant filter is better for CCD in terms of detection time and estimation accuracy. With the given constant false alarm rate, CCD detection threshold can be obtained. Furthermore, the sigma-inflation method is used to compensate the non-perfect distribution of the constructed test statistics. The real-world experiment of GPS and BeiDou is implemented to make a comparative analysis. The experimental result shows that the two-order detection method is more applicable to BDS due to the better availability. © 2015 Technical Committee on Control Theory, Chinese Association of Automation. Source

Luo Y.,Zhejiang University | Bai J.,Zhejiang University | Zhou X.,Zhejiang University | Huang X.,Zhejiang University | And 3 more authors.
Optics Express | Year: 2016

An inevitable problem of Panoramic Annular Lens (PAL) System is the blind area in the central part of image plane, which vastly reduces the pixel efficiency of detector. Here we present a design of PAL system based on dichroic filter, which can combine two channels of rays in different bands and image them on the same detector. The dichroic filter in this paper is designed to make ultraviolet rays reflect and visible rays transmit, and the ultraviolet rays are imaged on the PAL imaging area while the visible rays are imaged on the blind area of conventional PAL image plane. In order to image both bands of rays on the same plane, we add a correcting lens group in front of PAL system. As a result, the FOV of ultraviolet channel is ranging from 30°∼90° and the one of visible channel is ranging from 0°∼10°. © 2016 Optical Society of America. Source

Yuan G.-N.,Harbin Engineering University | Zuo Z.-D.,Harbin Engineering University | Zuo Z.-D.,Huazhong Institute of Electro Optics | Qu G.-T.,Harbin Engineering University | Ji H.,Harbin Engineering University
Huazhong Keji Daxue Xuebao (Ziran Kexue Ban)/Journal of Huazhong University of Science and Technology (Natural Science Edition) | Year: 2013

In order to suppress the system chattering exist in the classical sliding variable structure control and simplify the computational process of second-order sliding variable structure controller, a reaching condition of second-order sliding variable structure control was proposed. When the control system was under the reaching condition, two results were got by applying the ordinary differential equations theory and Lyapunov stability theory: the one is the system phase trajectory can converge to the sliding mode in finite time; the other is the control system has excellent robustness. Finally, a system variable structure controller was designed with the reaching condition. Simulation results show that the reaching condition with excellent robustness can suppress the system chattering effectively. Source

Du Y.,Huazhong Institute of Electro Optics | Liu A.D.,Wuhan National Laboratory for Optoelectronics
Applied Mechanics and Materials | Year: 2013

A noncontacting velocimetry technique based on line scan sensor arrays is proposed. Auto-correlation method is the mainly velocity measurement algorithm before. In my research, I will introduce a novel spatial filtering method based on line scan sensor for noncontacting velocimetry. When used for measuring a vehicle's velocity, the variation of the distance between the sensor and the road may cause a primary source of errors. In this paper, an adaptive Double-channel optical system is recommended to eliminate the errors, and we verify the effectiveness of the design in theory. © (2013) Trans Tech Publications, Switzerland. Source

Wang S.,Huazhong Institute of Electro Optics | Zeng X.H.,Huazhong Institute of Electro Optics Wuhan
Applied Mechanics and Materials | Year: 2013

This paper has described the status and role of the strapdown mirror control technology. It has analyzed the emphasis and difficulty in the study. In order to achieve higher system reliability and improve performance and eliminate all kinds of error of strapdown stable platform process what are stabilization while reducing the volume. In-depth analysis of the swing ship is on strapdown platform and mirror effect. The boat rocking and the sight stabilization mathematical model of mirror rotating. A study on the simulation what uses the MATLAB. By establishing the model of boat rocking, what analysis of the swing's influence on the mirror steady accuracy and tracking accuracy. The existing stable servo control and principle has been detailed analysis. Through the simulation studies what compared their advantages and disadvantages. Also it has studied the coning error compensation method and the kalman filtering what influenced on the accuracy of strapdown mirror control system. © (2013) Trans Tech Publications, Switzerland. Source

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