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基于状态反馈H_∞算法的高速水翼双体船姿态控制 被引量:1
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作者 任俊生 杨盐生 《中国航海》 CSCD 北大核心 2004年第2期29-32,77,共5页
研究基于状态反馈H∞算法的高速水翼双体船在波浪中运动的姿态控制器的设计。首先对水翼双体船运动的非线性数学模型在平衡点线性化,建立水翼双体船的线性模型;然后应用状态反馈H∞算法设计水翼双体船的姿态控制器;最后利用Matlab的Simu... 研究基于状态反馈H∞算法的高速水翼双体船在波浪中运动的姿态控制器的设计。首先对水翼双体船运动的非线性数学模型在平衡点线性化,建立水翼双体船的线性模型;然后应用状态反馈H∞算法设计水翼双体船的姿态控制器;最后利用Matlab的Simulnk工具箱,以高速水翼双体船HC200B A1为例进行仿真研究,结果表明该控制器设计能够有效地减少波浪引起的不利船体摇荡,使得船体在波浪中保持在预定的姿态。在同样参数条件下,对状态反馈H∞控制器与线性二次型调节器(LQR)设计的控制效果进行比较,显示前者的控制效果要优于后者。 展开更多
关键词 状态反馈h∞算法 高速水翼双体船 姿态控制器 设计 线性模型 仿真
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H_∞算法在车体振动控制中的应用 被引量:1
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作者 李宁洲 罗冠炜 《兰州交通大学学报》 CAS 2004年第1期102-106,共5页
应用H∞控制方法设计输出反馈控制器对机车车体垂向振动进行半主动控制,采用数值方法对设计结果进行仿真.结果表明,加入控制器后的悬挂系统对来自轨面的扰动对车体振动的影响有较强的抑制作用.
关键词 h∞算法 车体振动控制 反馈控制器 机车工程 悬挂系统
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穿浪双体船T型水翼状态反馈H∞控制器设计 被引量:4
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作者 张松涛 孙明晓 +1 位作者 梁利华 姜见龙 《舰船科学技术》 北大核心 2014年第10期78-82,共5页
穿浪双体船在海洋中高速航行时,纵向运动会对其性能造成不利影响,产生的垂向加速度使乘员晕船,设备短期失效。为了解决此问题,首先建立穿浪双体船纵摇和垂荡运动模型,然后运用切片理论求解运动方程中的水动力系数,将随机海浪作为外界干... 穿浪双体船在海洋中高速航行时,纵向运动会对其性能造成不利影响,产生的垂向加速度使乘员晕船,设备短期失效。为了解决此问题,首先建立穿浪双体船纵摇和垂荡运动模型,然后运用切片理论求解运动方程中的水动力系数,将随机海浪作为外界干扰,以T型水翼为纵向运动稳定装置,进而建立带T型水翼的穿浪双体船纵向运动模型。最后以90 m长的穿浪双体船为研究对象,利用状态反馈H∞控制策略设计控制器,对船体的纵摇和垂荡进行仿真实验。结果表明:状态反馈H∞控制器可有效地减小船舶纵向运动,降低晕船率,为减小高速船纵向运动提供可靠实用的方法。 展开更多
关键词 穿浪双体船 T型水翼 纵向运动 垂向加速度 状态反馈h∞算法 晕船率
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H.263 VIDEO CODEC IMPLEMENTATION BASED ON MULTIMEDIA DSP
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作者 Zhu Xiuchang Liu Feng Hu Dong (Department of Information Eng., Nanjing Institute of Posts and Telecommunications, Nanjing 210003) 《Journal of Electronics(China)》 2003年第2期128-131,共4页
This letter introduces the implementation of H.263 video codec based on multimedia DSP TM1300, and discuses several key problems related to video coding.
关键词 Video communication h.263 Algorithm optimization TM1300
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Improved Rate Control Using Statistical Information in Unit-Layer for H.264/AVC
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作者 Myoung-jin KIM Min-cheol HONG 《Journal of Measurement Science and Instrumentation》 CAS 2011年第3期256-259,共4页
The purpose of this paper is to improve allocation of the number of bits by estimating the target bits in H.264/AVC rate control.In the scheme,an enhancement method of the target unit-layer bit allocation is proposed,... The purpose of this paper is to improve allocation of the number of bits by estimating the target bits in H.264/AVC rate control.In the scheme,an enhancement method of the target unit-layer bit allocation is proposed,which uses a frame and unit complexity estimation to improve the existing mean absolute difference(MAD)complexity measurement.Using the statistical characteristics,we obtain change of occurrence bit about QP to apply the bit amount by QP from the video characteristics in the estimated bit amount of the current frame.Simulation results show that not only the proposed rate control scheme could achieve time saving of more than 99% over existing rate control algorithm,but also PSNR and bit rate were almost the same as the performance in all the sequences. 展开更多
关键词 bit rate control MAD unit-layer statistical information
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Proximal point algorithm for a new class of fuzzy set-valued variational inclusions with (H,η)-monotone mappings
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作者 李红刚 《Journal of Chongqing University》 CAS 2008年第1期79-84,共6页
We introduced a new class of fuzzy set-valued variational inclusions with (H,η)-monotone mappings. Using the resolvent operator method in Hilbert spaces, we suggested a new proximal point algorithm for finding approx... We introduced a new class of fuzzy set-valued variational inclusions with (H,η)-monotone mappings. Using the resolvent operator method in Hilbert spaces, we suggested a new proximal point algorithm for finding approximate solutions, which strongly converge to the exact solution of a fuzzy set-valued variational inclusion with (H,η)-monotone. The results improved and generalized the general quasi-variational inclusions with fuzzy set-valued mappings proposed by Jin and Tian Jin MM, Perturbed proximal point algorithm for general quasi-variational inclusions with fuzzy set-valued mappings, OR Transactions, 2005, 9(3): 31-38, (In Chinese); Tian YX, Generalized nonlinear implicit quasi-variational inclusions with fuzzy mappings, Computers & Mathematics with Applications, 2001, 42: 101-108. 展开更多
关键词 variational inclusion h η)-monotone mapping resolvent operator technique fuzzy set-valued mapping proximal point algorithm: convergence of numerical methods
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Complexity scalable control algorithm for intra coding in H.264 under energy constraints
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作者 Gao Xuejun Lam Kin Man +1 位作者 ZhuoLi ShenLansun 《High Technology Letters》 EI CAS 2010年第3期274-279,共6页
In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is ... In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is proposed, based on the rearrangement of the order of candidate modes and an efficient complexity allocation and control (CAAC) scheme at the macroblock (MB) level. The candidate modes of each MB are rearranged according to the local-edge information. Experimental results show that our proposed algorithm can make an appropriate cut-off point of the candidate modes sequence adaptively according to the current energy condition of a mobile device, so as to adjust the complexity at any level while maximizing the video quality, which can prolong the operational lifetime of the battery with minimum degradation in video quality. 展开更多
关键词 complexity scalable control complexity allocation rearrangement of candidate modes intra coding h. 264 energy constraints
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Fast Motion Estimation Algorithm with Edge Alignment for H.264 Encoder
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作者 Rastislav Adamek Gabriela Andrejkova 《Computer Technology and Application》 2013年第7期341-345,共5页
Image sequences processing and video encoding are extremely time consuming problems. The time complexity of them depends on image contents. This paper presents an estimation of a block motion method for video coding w... Image sequences processing and video encoding are extremely time consuming problems. The time complexity of them depends on image contents. This paper presents an estimation of a block motion method for video coding with edge alignment. This method uses blocks of size 4 × 4 and its basic idea is to find motion vector using the edge position in each video coding block. The method finds the motion vectors more accurately and faster than any known classical method that calculates all the possibilities. Our presented algorithm is compared with known classical algorithms using the evaluation function of the peak signal-to-noise ratio. For comparison of the methods we are using parameters such as time, CPU usage, and size of compressed data. The comparison is made on benchmark data in color format YUV. Results of our proposed method are comparable and in some cases better than results of standard classical algorithms. 展开更多
关键词 Codec h.264 ENCODER edge detection EVO (Enabling Virtual Organizations) conference system.
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A Fast Half-Pixel Motion Estimation Algorithm and Efficient Interpolation Hardware Architecture Unit for H.264/AVC
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作者 Zuo Chunsheng Lin Tao Fan Jing 《International Journal of Technology Management》 2015年第1期73-76,共4页
In this paper, a fast half-pixel motion estimation algorithm and its corresponding hardware architecture is presented. Unlike three steps are needed in typical half-pixel motion estimation algorithm, the presented alg... In this paper, a fast half-pixel motion estimation algorithm and its corresponding hardware architecture is presented. Unlike three steps are needed in typical half-pixel motion estimation algorithm, the presented algorithm needs only two steps to obtain all the interpolated pixels of an entire 8x8 block. The proposed architecture works in a parallel way and is simulated by Modelsirn 6.5 SE, synthesized to the Xilinx Virtex4 XC4VLX15 FPGA device. The implementation results show that this architecture can achieve 190 MHz and 10 clock cycles are reduced to complete the entire interpolation process when compared with typical half-pixel interpolation, which meets the requirements of real-time application for very high defination videos. 展开更多
关键词 Motion estimation half-pixel interpolation hardware architecture FPGA
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飞机结冰在线辨识方法研究 被引量:1
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作者 丁娣 车竞 +1 位作者 汪清 钱炜祺 《空气动力学学报》 CSCD 北大核心 2016年第6期704-708,737,共6页
开展飞机结冰气动特性在线辨识研究,不仅可以用于分析结冰对飞机气动特性的影响,而且对于飞机结冰在线识别具有重要的意义。近年来卡尔曼滤波和H_∞算法在飞机结冰在线辨识中应用较多,二者均具有可靠性高、收敛快等特点,但对于噪声环境... 开展飞机结冰气动特性在线辨识研究,不仅可以用于分析结冰对飞机气动特性的影响,而且对于飞机结冰在线识别具有重要的意义。近年来卡尔曼滤波和H_∞算法在飞机结冰在线辨识中应用较多,二者均具有可靠性高、收敛快等特点,但对于噪声环境下算法的可靠性和精度评估还不够充分。本文针对飞机结冰在线辨识需求,探讨了扩展卡尔曼滤波和H_∞算法作为结冰在线辨识算法的应用。首先通过NASA双水獭结冰研究飞机算例,利用扩展卡尔曼滤波和H_∞算法,辨识双水獭飞机结冰后的俯仰方向导数,通过考虑阵风扰动和测量噪声后的仿真数据快速估计该飞机俯仰方向上的三个稳定和控制导数,并将辨识结果与参考值对比,发现两种算法均能在2s之内快速收敛到参考值附近,且滤波得到的状态量与仿真数据吻合较好,说明算法可靠性高且收敛快,具备飞机结冰在线探测的能力。在此基础上利用不同测量噪声统计特性的仿真数据,评估测量噪声对两种算法辨识精度的影响,经分析发现随着测量噪声标准差取值增大,扩展卡尔曼滤波辨识结果精度明显降低,而H_∞算法的辨识精度变化较小,说明扩展卡尔曼滤波辨识精度依赖于噪声先验信息的准确性,而H_∞算法不依赖于噪声先验信息,即使数据质量较差,H_∞算法也能得到精度相当的辨识结果。 展开更多
关键词 飞机结冰在线辨识 扩展卡尔曼滤波 h∞算法 稳定和控制导数 辨识精度 测量噪声 噪声统计特性
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SPATIAL ERROR CONCEALMENT BASED ON MOJETTE TRANSFORM
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作者 Ji Wenping Shen Lansun 《Journal of Electronics(China)》 2007年第3期417-420,共4页
This letter presents a novel spatial error concealment algorithm for the H.264 video coding. The error concealment algorithm is based on directional interpolation. Mojette transform is used to estimate the orientation... This letter presents a novel spatial error concealment algorithm for the H.264 video coding. The error concealment algorithm is based on directional interpolation. Mojette transform is used to estimate the orientation features of the damaged blocks,and the image is interpolated in the appro-priate directions. The proposed method is compared with bilinear interpolation algorithm in the ref-erence implementation of H.264 and all directional interpolation. Experimental results prove that the proposed algorithm has better subjective and objective image reconstruction quality. 展开更多
关键词 h.264 Error concealment Mojette transform Video communication
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Wiener-Hopf Operators on Discrete Abelian Groups
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作者 许庆样 胡俊云 《Journal of Mathematical Research and Exposition》 CSCD 1999年第3期549-553,共5页
The groupoid approach to study Wiener-Hopf operators on discrete abelian groups is realized.
关键词 GROUPOID C-ALGEBRA discrete abelian group
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A Rate-distortion Based Quantization Level Adjustment Algorithm in Block-based Video Compression 被引量:1
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作者 蒋伟 王嘉 孙军 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第3期343-349,共7页
In this paper, a rate-distortion based quantization level adjustment (RDQLA) algorithm is presented. Based on the rate-distortion criterion, the quantization level adjustment algorithm effectively improves coding ef... In this paper, a rate-distortion based quantization level adjustment (RDQLA) algorithm is presented. Based on the rate-distortion criterion, the quantization level adjustment algorithm effectively improves coding efficiency by adaptively optimizing quantization levels of the signals near the boundaries of quantization cells and adjusting quantization levels per block. In addition, it has no overhead and is fully compatible with the existing compression standards. The proposed algorithm can be applied in any block based image and video coding method. In particular, the algorithm has been verified on the platform of H.264. Experimental results show that the proposed algorithm improves objective and subjective performances substantially. It is shown that the proposed algorithm has a gain of several dB comparing with the newest H.264 standard for high bit rates. 展开更多
关键词 RATE-DISTORTION QUANTIZATION DEAD-ZONE video standards
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