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Finite time control for probe descent near small bodies

Computer Modelling and New Technologies 2014年第9期18卷 468-476页

作者： Liang, Chunhun Li, Yuanchun College of Communication Engineering Jilin University Changchun China College of Electrical and Information Changchun Institute of Technology Changchun China Department of Control Engineering Changchun University of Technology Changchun China

For the purpose of probe soft landing on small bodies safely, this paper focuses on the orbital dynamics and describes a new control algorithm for the probe descent near a rotating small body. The general formulation of the probe equations of motion in the Body-Fixed Coordinate system is obtained through Newton's second law firstly. Then the nominal polynomial trajectory of vertical direction is planned in the condition of fuel consumption suboptimum. Considering uncertainties and perturbations, the control laws based on Adaptive Terminal Sliding Mode with compensation term are developed to track the desired trajectory finally. Suppose the initial conditions presented in this paper, position and velocity errors tend to zero in the finite time in the phase of sliding mode motion so it will make the task succeed during descent phase near small bodies. Finally, the effectiveness of the guidance and control algorithm is verified by MATLAB simulations. The proposed algorithm can fast and accurately track the planned trajectory in the finite time and is robust to parameter uncertainty, feedback state error and external disturbances. The validity is conformed by computer simulation.

关键词： Probes

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An ID-based short group signature scheme

Journal of Software

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Journal of Software 2013年第3期8卷 554-559页

作者： Chen, Xiangguo Zhou, Shaojie Guo, Lifeng Yu, Jia Ma, Huiran School of Information Engineering Qingdao University Qingdao 266071 China College of Measure-Control Technology and Communication Engineering Harbin University of Science and Technology Harbin 150040 China School of Computer and Information Technology Shanxi University Taiyuan 030006 China

A new ID-based group signature scheme, in which group managers and group members are all ID-based, is presented in this paper. Our scheme is obtained by using a new way to the construction of group signature schemes and based on an ID-based signature scheme from bilinear pairing. Due to the nice and simple constructive method and the sound properties of bilinear pairing, it is shown that the proposed scheme is very simple and practical and has the advantages of concurrent join, immediate revocation, easy tracing and short signature length. The security analysis is also under the formal security notion of an ID-based group signature scheme. © 2013 ACADEMY PUBLISHER.

关键词： Authentication

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Car tracking algorithm based on Kalman filter and compressive tracking

Car tracking algorithm based on Kalman filter and compressiv...

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Congress on Image and Signal Processing, CISP

作者： Hui Li Peirui Bai Huajun Song College of Electronics Communication and Physics Shandong University of Science and Technology Qingdao China College of Information and Control Engineering China University of Petroleum (East China) Qingdao China

ISBN: (纸本)9781479958368

According to the features of traffic supervisory video, Compressive Tracking (CT) algorithm is adopted to detect and track the moving car. When the camera angle, moving vehicle scale and background changed, the CT algorithm still has a strong robustness. However, the algorithm is invalid when car is sheltered so that the tracked car cannot be located. In order to overcome this problem, a new method which uses Kalman filter to predict the sheltered car moving position is proposed. Experimental results show that despite changed in tracking window size and target location or sheltered overall or partly, the proposed algorithm can also track that car successfully, and has good real-time performance which meets the requirements of engineering application.

关键词： Target tracking Prediction algorithms Vehicles Computed tomography Kalman filters Feature extraction

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Analysis of three-dimensional reality modeling algorithm in animation design

Analysis of three-dimensional reality modeling algorithm in ...

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2nd International Conference on Precision Mechanical Instruments and measurement technology, ICPMIMT 2014

作者： Cai, Bai Chuan Mei, Rong Fang Mei, Jian Guo Yang, Bo School of Software East China Normal University Putuo shanghai 200062 China Department of electronic information and control engineering Yibin Vocational and Technical College Yibin Sichuan 644003 China School of computer and communication engineering University Of Chongqing Shapingba Chongqing 400044 China Chongqing Municipal Health Technical School Banan chongqing 401320 China College of Art and Design Shaanxi University of Science and Technology Shanxi Xian710021 China

ISBN: (纸本)9783038351948

During animation design process, when the overlap of animation graphics is overtopping, inaccurate three-dimensional feature points appear in the established model, which resulting in low fidelity of model. For this drawbacks, a three-dimensional reality animation design modeling based on an optimization algorithm of animation modeling fidelity is proposed. Triangle refinement method is utilized to refine feature points distributed disorderly in the three-dimensional animation model, so as to obtain a three-dimensional animation composed of triangles, according to the method of calculating the intersection of intersecting triangles, optimal triangles can be achieved, i.e. the new three-dimensional coordinate points are acquired. Afterwards, two-dimensional coordinate calculation is processed for the new added points to get the exact coordinates of the point in the three-dimensional animation model, eventually obtain a three-dimensional animation model with high degree of fidelity. © (2014) Trans Tech Publications, Switzerland.

关键词： Three dimensional computer graphics

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Simulation on eliminating interference in long-distance communication

Simulation on eliminating interference in long-distance comm...

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2nd International Conference on Precision Mechanical Instruments and measurement technology, ICPMIMT 2014

作者： Mei, Rong Fang Cai, Bai Chuan Mei, Jian Guo Li, Xiu Ying School of computer and communication engineering University Of Chongqing Shapingba Chongqing 400044 China Department of electronic information and control engineering Yibin Vocational and Technical College Yibin Sichuan 644003 China School of Software East China Normal University putuo shanghai 200062 China Chongqing Municipal Health Technical School banan chongqing 401320 China Institute of Computer Technology Southwest Jiaotong University Chengdu Sichuan 610031 China Wuliangye Institute of Technology Yibin Vocational and Technical College Yibin Sichuan 644003 China

ISBN: (纸本)9783038351948

Due to wide frequency band, the long-distance communication is prone to be jammed by traditional radios. Furthermore, severe interference will lead to serious deterioration of performance. To solve this problem, the paper proposes energy-balance interference eliminated method and mixed communication algorithm, namely interference cancellation system model. The system elects a cluster head by utilizing the residual energy of nodes and the distance between cluster heads to balance the energy consumption and maximum the life cycle of the network. A Boolean vector corresponding to a random number defined is applied to this interference cancellation system. Experimental results show that under the premise of accurate channel estimation, systems using this technology to eliminate external interference in long-distance communication system have practical significance. © (2014) Trans Tech Publications, Switzerland.

关键词： Energy utilization

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Design of spread-spectrum communication system based on FPGA

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Sensors and Transducers 2013年第SPEC.ISSUE期23卷 49-53页

作者： Yan, Yixin Liu, Xiaolei Zhang, Xiaobing College Measurement Control Technology and Communication Engineering Harbin University of Science and Technology Harbin Heilongjiang 150080 China

Spread spectrum communication technology, compared with the conventional communication technology, has many characteristics, such as a low interception rate, strong anti-noise performance, noise immunity, information hiding and multiple access communication. Widely used in military communication and civil communication at present, it is the core technology in the third generation mobile communication standards and has become one of the three high-tech communication transmission modes to enter the information age. The communication system of direct sequence spread spectrum (DSSS) is most common in the spread spectrum communication technology, and this type of system was studied in this research. FPGA is one of hot research topics on hardware design. It has been widely used in the algorithm implementation and product prototype verification due to its rich logical unit, high integration, flexible configuration and many other advantages. Design and implementation on digital communication system with a more complex function have become reality on the hardware platform of FPGA with the considerable development of modern microelectronics especially in recent years. The research studied the various parts of key technologies, introduced the various algorithms of the most critical synchronization technologies (including pseudo-code acquisition, pseudo-code tracking, and carrier synchronization) in system in detail and gave their simulation results by establishing a complete simulation system for Direct Sequence Spread Spectrum. © 2013 IFSA Publishing. All rights reserved.

关键词： Field programmable gate arrays (FPGA)

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A novel method for measurement of fetal volume from US images using segmentation techniques

A novel method for measurement of fetal volume from US image...

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International Conference on Green Computing communication and Electrical engineering (ICGCCEE)

作者： P. Hari Krishnan V. Karthickeyan P. Ramamoorthy Department of Electrical Engineering Anna University Chennai India M.E Control and Instrumentation Anna University Regional Centre Coimbatore SNS College of Technology Electronics & Communication Engineering Coimbatore

ISBN: (纸本)9781479949816

The paper presents a novel method to measure the volume of a fetus from ultrasonic sound image using image processing technique. Even though Ultrasonic image are poor in diagnostic quality and highly noise susceptible, they are preferred for the reason that Ultrasound imaging techniques were the safest for diagnosing pregnant women fetus, since they are almost free from hazardous radiation. Edge enhancement is made to improve this poor quality image which is to be used as input image for segmentation simultaneously smoothens the unwanted image edge to enhance only important edges of fetus. Anisotropic diffusion technique are used for image enhancement technique. Iso-intensity and Edge-focusing segmentation techniques were applied to US-images to obtain appropriate and clear edge image. By Iso-intensity contour approach, the pixel values with equal intensities were selected. Another contour selection technique, which had been used, was the Edge-focusing technique, which makes use of the differences of importance between different edges in the image. Determining the contour as a set of the points in the 3D-volume was the foremost and important step in fixing the shape of the fetus. The natural shape of body or head is like a sphere or an ellipsoid, both of these figures have been fitted. After the process of fitting an analytical figure has been completed, the volume of fetus can be calculated. These image processing techniques are applied to the fetal image through image processing tool in Matlab software. Post-processing operations are required after each techniques is used.

关键词： Image edge detection Image segmentation Fetus Mathematical model Equations Ultrasonic imaging Harmonic analysis

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The design of a portable instrument for straightness measurement of large machine tool

The design of a portable instrument for straightness measure...

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2013 International Conference on Mechanical and Electronics engineering, ICMEE 2013

作者： Zhang, Ren Sun, Xue Guo, Xiao Yan Chen, Jie College of Information Engineering Tarim University Xinjiang alar 843300 China College of Measure-control Technology and Communication Engineering Harbin Univ.Sci.Tech Harbin 150080 China

ISBN: (纸本)9783037858103

The paper inctroduces the guide for the design of a portable instrument for straightness measurement of large machine tool. the measuring instrument is designed with two-quadrant photocell which is used as the position sensor, single-chip for the processor is MSP430F427 which have LCD driver circuit, the instrument is charged by lithium battery-powered. Its size is small, no external connection when it is used, data acquisition, processing and error displayed can be done in the part of light target. It have the advantage of convenience, simple and high measurement accuracy when it is used. © (2013) Trans Tech Publications, Switzerland.

关键词： Data acquisition

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A two-layer optimization framework for UAV path planning with interval uncertainties

A two-layer optimization framework for UAV path planning wit...

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IEEE Workshop on Computational Intelligence in Production and Logistics Systems (CIPLS)

作者： Bai Li Raymond Chiong Mu Lin School of Control Science and Engineering Zhejiang University Hangzhou China School of Design Communication and Information Technology The University of Newcastle Callaghan Australia College of Biomedical Engineering and Instrument Science Zhejiang University Hangzhou China

We propose a two-layer optimization framework for the unmanned aerial vehicle path planning problem to handle interval uncertainties that exist in the combat field. When evaluating a candidate flight path, we first calculate the interval response (i.e., the upper and lower bounds) of the candidate flight path within the inner layer of the framework using a collocation interval analysis method (CIAM). Then, in the outer layer, we introduce a novel criterion for interval response comparison. The artificial bee colony algorithm is used to search for the optimal flight path according to this new criterion. Our experimental results show that the CIAM adopted is a feasible option, which largely eases the computational burden. Moreover, our derived flight paths can effectively handle bounded uncertainties without knowing the corresponding uncertainty distributions.

关键词： Uncertainty Path planning Cost function Educational institutions Programming Bismuth

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Design of automatic shifting controller for electric vehicle with five speed transmission

Design of automatic shifting controller for electric vehicle...

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8th International Forum on Strategic technology, IFOST 2013

作者： Jingbo, Xu Xiaohong, Xu Xin, Su Xin, Guo College of Measure-control Technology and Communication Engineering Harbin University of Science and Technology Harbin China Higher Educational Key Laboratory for Measuring Control Technology and Instrumentations of Heilongjiang Province Harbin China Department of Textile Engineering Shazhou Professional Institute of Technology Zhangjiagang China

ISBN: (纸本)9781479909315

On the basis of the motor controller dedicated for electric vehicle, the vehicle realizes automatic transmission, through development of the automatic shift controller. The function of gear-selection and gear-shifting is implemented through air cylinder and shifting fork driven by electromagnetic valve. The MeU detects the vehicle speed, the motor rotating speed, the gear position, the accelerator position and the motor current, adjusts the motor rotating speed and controls the electromagnetic valves. The algorithm of speed tracking adjusts the motor speed accurately and rapidly, and provides guarantee for the dynamic shift. According to vehicle and motor running status, the two-parameter shift schedule combined with the current parameter, improves the motor efficiency and makes the shifting process more smoothly. © 2013 IEEE.

关键词： Electric vehicles

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