期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
一种基于CI因子图的多机器人2D地图融合算法 被引量:4
1
作者 王巍 浦云明 李旺 《机器人》 EI CSCD 北大核心 2017年第6期872-878,共7页
针对地图融合时多机器人位姿估计过程中互协方差未知的问题,提出了一种基于协方差交叉点(covariance intersection,CI)因子图的2D地图融合算法.首先通过坐标变换矩阵实现机器人坐标到全局坐标的转换,然后以最小化非线性性能指标为原则... 针对地图融合时多机器人位姿估计过程中互协方差未知的问题,提出了一种基于协方差交叉点(covariance intersection,CI)因子图的2D地图融合算法.首先通过坐标变换矩阵实现机器人坐标到全局坐标的转换,然后以最小化非线性性能指标为原则求取局部的估计信息权重,通过算法融合各局部估计信息,计算出融合点的位姿和互协方差.最后通过协方差通用公式,计算出融合点到下一级变量节点的概率约束(协方差),进而完成因子图融合.实验结果表明,该算法具有一定的可行性. 展开更多
关键词 多移动机器人系统 协方差 因子图算法 协方差交叉点算法
原文传递
QIM digital watermarkingbased on LDPC code and messagepassingunder scalingattacks
2
作者 崔鑫 颜斌 +1 位作者 贾霞 王亚菲 《Journal of Measurement Science and Instrumentation》 CAS 2014年第1期37-40,共4页
Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronizati... Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronization attacks of QIM digital watermarking,a low density parity check (LDPC) code-aided QIM watermarking algorithm is proposed,and the performance of QIM watermarking system can be improved by incorporating LDPC code with message passing estimation/detection framework.Using the theory of iterative estimation and decoding,the watermark signal is decoded by the proposed algorithm through iterative estimation of amplitude scaling parameters and decoding of watermark.The performance of the proposed algorithm is closer to the dirty paper Shannon limit than that of repetition code aided algorithm when the algorithm is attacked by the additive white Gaussian noise.For constant amplitude scaling attacks,the proposed algorithm can obtain the accurate estimation of amplitude scaling parameters.The simulation result shows that the algorithm can obtain similar performance compared to the algorithm without desynchronization. 展开更多
关键词 digital watermarking quantization index modulation (QIM) message passing algorithm based on factor graph low density parity check (LDPC) code amplitude scaling attack
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部