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	Research on model reference sliding mode control in roll stabilization of aerocraft (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China Chu H.-R. 收藏 \| 浏览/下载：46/0 \| 提交时间：2013/03/25 Aimed at aerospace roll stabilization control arithmetic based on model reference sliding mode variable structure theory and chattering reduction arithmetic are formulated. Correctness and validity of arithmetic are analyzed. With flight dynamics the roll-loop mathematic model and reference model are established. Sliding hyperplane is deduced based on model reference sliding mode variable structure theory. Combing with reaching law control law is derived and stability of roll-loop is analyzed. Chattering of aileron instructions is alleviate by using boundary layer approach. Digital flying simulation result shows that variable structure control arithmetic realized roll stabilization control the roll angle is less than 5.3 under powered flight and that of unpowered flight is less than 0.5 respectively. The command fin angle is less than 1.5. High frequency chattering of fin command nearby the minimum velocity was trailed off by chattering reduction arithmetic. The sliding mode control arithmetic show good performance when aerodynamic coefficients varies 20%. The control arithmetic is easy to be implemented for its simplicity. 2011 IEEE.
	Gimbal displacement error analysis on an electro-optical seeker (EI CONFERENCE) 会议论文 OAI收割 Optical Design and Testing IV, October 18, 2010 - October 20, 2010, Beijing, China 作者: Zhang X.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：40/0 \| 提交时间：2013/03/25 It is essential to analyze the gimbal displacement errors for a seeker due to the importance for cueing of targets and tracking for the final approach. Otherwise for a seeker electro-driven with a concentric glass dome the large errors will decrease the picking pointing and tracking precision rooted from the displacement errors existing between the rotation center of the optical system and the gimbal. And the gimbaled camera system displacement errors are never eliminated but reduced due to the geometric errors consists of geometric tolerances of gimbal structure manufacture installation and vibration coming from working environment. In this paper the gimbal displacement errors in an electro-optically stabilized platform resulting from geometric errors and environment errors were analyzed and shown in detail. The mathematical modal of the gimbal displacement errors created based on multi-body dynamics demonstrated the connection between the gimbal displacement errors and the stabilized platform. Taking a visible light image seeker as a case the diameter is 120mm and the geometric tolerances came from the values of primary design and the vibration data came from the environmental vibration test on the pitch-yaw seeker and at the same time the errors resulting from installation were considered too. Based on calculating the maximum gimbal displacement error will reach to 0.2mm for pitching angle smaller than 40 and yawing angle smaller than 60. However the critical parts have been found out according to the probability theory and the reliability analysis successfully used in the paper and finally the maximum gimbal displacement error reduced to 0.1mm which is acceptable corresponding to the picking pointing and tracking precision for an optical imaging seeker. 2010 Copyright SPIE - The International Society for Optical Engineering.
	Quaternion based assessment method for color image fusion algorithms (EI CONFERENCE) 会议论文 OAI收割 2010 3rd International Congress on Image and Signal Processing, CISP 2010, October 16, 2010 - October 18, 2010, Yantai, China 作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y. 收藏 \| 浏览/下载：30/0 \| 提交时间：2013/03/25 A new approach to assess the performance of color image fusion algorithms is proposed. The color information is fully used by this method. Quaternions are used to encode the pixels in a color image into a quaternion matrix. Local variance of the luminance layer of the color image is taken as the real part of a quaternion then the three RGB channels of the color image are encoded into the three imaginary parts of a quaternion. The angle between the singular value feature vectors of the quaternion matrices corresponding to one of the source image and the fused image is used to measure their structural similarity. Edge information transferring is used to balance the sensitivity of the assessment methods. Experimental results show that the proposed assessment method is better consistent with the HVS than some of the state-of-the-art method. Accurate assessment results can be given by the proposed method for various of color image fusion algorithms by using the source images and the fused image. 2010 IEEE.
	A local feature based simplification method for animated mesh sequence (EI CONFERENCE) 会议论文 OAI收割 2010 2nd International Conference on Computer Engineering and Technology, ICCET 2010, April 16, 2010 - April 18, 2010, Chengdu, China 作者: Wang B.; Wang B.; Zhao J.; Zhang S. 收藏 \| 浏览/下载：35/0 \| 提交时间：2013/03/25 Although animated meshes are frequently used in numerous domains only few works have been proposed until now for simplifying such data. In this paper we propose a new method for generating progressive animated models based on local feature analysis and deformation area preservation. We propose the use of solid angle and height value for a non-hyperbolic vertex to define the local feature parameter. This local factor is embedded to the vertex quadric error matrix when calculating the edge collapse cost. In order to preserve the areas with large deformation we add deformation degree weight to the aggregated quadric errors when computing the unified edge contraction sequence. Finally a mesh optimization process is proposed to further reduce the geometric distortion for each frame. Our approach is fast easy to implement and as a result good quality dynamic approximations with well-preserved fine details can be generated at any given frame. 2010 IEEE.
	The method on the measurement of the aircraft attitude by the spatial cosines relationship of the single station and planes to the intersection the multi-station of electro-optical theodolite (EI CONFERENCE) 会议论文 OAI收割 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China Zhao L.-R.; Cao Y.-G. 收藏 \| 浏览/下载：23/0 \| 提交时间：2013/03/25 In order to realize the aircraft attitude measurement The paper advances electro-optical theodolite methods of measuring the aircraft attitude by using the spatial cosines relationship the single station theodolite and how to use intersection of the multi-station theodolite. The single station theodolite was introduced in a measured distance from the aircraft posture information. An exhaustive approach was used to access to the aircraft axis of the feature points and the location in the space was used to obtain space posture parameters. The multi-station theodolite was introduced to get the information of the aircraft flight attitude by method of using planes to the intersection. Two-dimensional image to obtain objective axis by fitting algorithm using Hough transform. And then Calculate the vertical distance of the origin to the target of the central axis and the origin to the target of the central axis of the angle between the normal and the X-axis obtaining the linear equation in the two-dimensional plane. Two-dimensional axis of the target image and the camera system's optical center only identified a space plane. The aircraft yaw axis angle and pitch angle can be obtained by getting the space axis using plains to the intersection method. Experimental results show that attitude angle error of the single station theodolite is less than 1 when its distance is less than 6000m and attitude angle error of the multi-station theodolite is less than 0.6 when its intersection angle is between 30 and 150. In this paper according to test result of precision comparing the mathematical model is correct and the algorithm is reasonable in extracting effective parameters of the aircraft's attitude. 2010 IEEE.
	Assessment of color image fusion algorithms based on quaternion singular value decomposition (EI CONFERENCE) 会议论文 OAI收割 MIPPR 2009 - Remote Sensing and GIS Data Processing and Other Applications: 6th International Symposium on Multispectral Image Processing and Pattern Recognition, October 30, 2009 - November 1, 2009, Yichang, China 作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y. 收藏 \| 浏览/下载：30/0 \| 提交时间：2013/03/25 In this paper a new approach to objectively assess the performance of image fusion algorithms is proposed. It is based on the quaternion representation for the structural information of color images. Quaternions are used to encode the pixels of a color image into a quaternion matrix. Local variance of the luminance layer of color image is taken as the real part of a quaternion then the three RGB channels of the color image are encoded into the three imaginary parts of the quaternion. The angle between the singular value feature vectors of the quaternion matrices corresponding to the source image and the fused image is used to measure the structural similarity of them. Different weight is given to the source images by using variance. The experiment results show that the proposed assessment method is consistent with the HVS. The color information of a color image can be fully used by this method. It can give an accurate assessment result for each fusion algorithm by using the source images and the fused image. 2009 Copyright SPIE - The International Society for Optical Engineering.
	三维重建和摄像机标定技术研究学位论文 OAI收割工学博士, 中国科学院自动化研究所: 中国科学院研究生院, 2004 作者: 祝海江收藏 \| 浏览/下载：54/0 \| 提交时间：2015/09/02 三维重建摄像机标定平移运动对应消失线接近角 3D reconstruction camera calibration translation motion corresponding vanishing line the approach angle