共查询到18条相似文献,搜索用时 218 毫秒
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基于Voronoi地图表示方法的同步定位与地图创建 总被引:1,自引:1,他引:0
针对基于混合米制地图机器人同步定位与地图创建 (Simultaneous localization and mapping, SLAM)中地图划分方法不完善的问题, 提出了基于Voronoi地图表示方法的同步定位与地图创建算法VorSLAM. 该算法在全局坐标系下创建特征地图, 并根据此特征地图使用Voronoi图唯一地划分地图空间, 在每一个划分内部创建一个相对于特征的局部稠密地图. 特征地图与各个局部地图最终一起连续稠密地描述了环境. Voronoi地图表示方法解决了地图划分的唯一性问题, 理论证明局部地图可以完整描述该划分所对应的环境轮廓. 该地图表示方法一个基本特点是特征与局部地图一一对应, 每个特征都关联一个定义在该特征上的局部地图. 基于该特点, 提出了一个基于形状匹配的数据关联算法, 用以解决传统数据关联算法出现的多重关联问题. 一个公寓弧形走廊的实验验证了VorSLAM算法和基于形状匹配的数据关联方法的有效性. 相似文献
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基于粒子滤波和点线相合的未知环境地图构建方法 总被引:1,自引:0,他引:1
针对粒子滤波处理未知环境地图构建时存在存储空间负荷高、计算量大的问题, 本文使用线段特征描述环境信息, 将点线相合的增量式地图构建方法引入粒子滤波中. 在每个粒子中保存对已构建线段特征地图的假设; 使用点线相合的位姿估计算法将观测信息引入重要性函数, 确定采样空间; 通过观测信息与已构建线段特征地图之间的相合关系更新粒子权重; 最后通过选择性重采样去除因匹配不当和误差积累产生的错误地图. 分析表明, 该算法的复杂度较低. 在真实传感器数据上的实验结果验证了该算法构建室内环境地图的有效性和鲁棒性. 算法所需存储空间和粒子数远小于现有粒子滤波地图构建方法. 相似文献
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数据关联是移动机器人同时定位与建图(SLAM)中的一个难点问题.将经典的单匹配最近邻(ICNN)算法和分枝限界联合匹配(JCBB)算法结合起来,提出了一种基于局部地图的混合数据关联方法.在SLAM数据关联过程中,首先采用ICNN算法在局部地图中进行数据关联,并判断关联结果的正确性,若有错则采用JCBB算法在错误匹配处周围的局部区域内重新进行数据关联,以纠正错误的关联结果.实验结果表明,该方法实时性强,精确度高,适用于不同复杂程度的环境. 相似文献
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一种基于特征地图的移动机器人SLAM方案 总被引:1,自引:0,他引:1
设计了一种结构化环境中基于特征地图的地图创建方案;采用激光测距仪进行特征地图创建,利用"聚合-分害虫-聚合"的方法来提取线段表示环境信息实现局部地图创建;为了实现移动机器人的同时定位与地图创建,采用扩展卡尔曼滤波方法对机器人的位姿与地图信息进行预测及更新,结合状态估计和数据关联理论,实验显示x的校正量保持在±0.9cm之内;y的校正量保持在±2.5cm之内;θ的校正量在±1.2之内,实现了基于扩展卡尔曼滤波器的SLAM. 相似文献
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为了创建AGV大范围全局导航地图,论文提出一种基于多摄像头的全局导航地图创建方法.首先,在AGV活动区域上方垂直安装多个摄像头采集大范围区域的局部图像;其次,通过相位相关法和改进的SURF特征匹配相结合的算法对四幅局部图像进行拼接;最后,采用基于粒子群的模糊C均值聚类算法对全局图像进行分割提取障碍物信息,并建立室内环境全局导航地图.实验表明该方法与现有算法相比具有更好的实时性,能够快速建立全局导航地图. 相似文献
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改进的极小连通支配集SLAM数据关联方法 总被引:2,自引:0,他引:2
地图的极小连通支配集(MCDS)方法解决了机器人同时定位与地图创建(SLAM)过程中数据关联的规模随地图的不断增长而增加的问题。为了进一步优化MCDS方法的性能,对它进行了两处改进:一是延迟建立极小连通支配集;二是自适应地搜索极小连通支配集。K时刻的极小连通支配集子图延迟一个时间步而在K+1时刻建立,根据环境特征的疏密,搜索与K时刻接近的N个时间步内获得的地图数据,同时应用联合相容检验准则和分支定界搜索算法进行数据关联。仿真结果表明,改进的极小连通支配集方法的数据关联结果是可信的,大大降低了算法计算复杂度。 相似文献
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基于局部纹理ASM模型的人脸表情识别 总被引:1,自引:0,他引:1
针对主动形状模型(ASM)迭代过程容易陷入局部最优解的不足,提出了一种基于局部纹理模型的改进ASM算法,即EWASM.在局部纹理模型构建中,以每个特征点的中垂线方向搜索其邻域信息以确定最佳匹配位置,对衡量匹配程度的马氏距离加以推广,进而得到改进的扩展加权局部纹理模型,它由中心局部纹理模型、前局部纹理模型和后局部纹理模型共3个子模型加权组成,并对加权参数进行实验优化,使各个特征点之间的联系更加紧密,模型的鲁棒性更好.通过表情识别实验对提出的EWASM算法和传统ASM算法进行对比,选用RBF神经网络分类器进行表情分类,实验结果表明EWASM算法收敛速度更快,识别率也得以提高,并解决了局部最小问题,能更有效地表征表情. 相似文献
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针对在移动机器人同时定位与建图(SLAM)过程中如何快速准确获取数据关联结果的问题,提出了一种基于DBSCAN(density-based spatial clustering of application with noise)聚类分组的快速联合兼容SLAM数据关联算法(DFJCBB).首先,采用局部关联策略将参与关联的特征点限定在局部地图中;其次,针对多数环境中量测都有较明显的分布,采用一种基于密度聚类的方法DBSCAN对当前时刻的量测进行分组,从而得到若干关联度小的观测小组;最后,在每个小组中采用联合兼容分支定界(JCBB)算法进行数据关联,以获得每个小组量测与局部地图特征之间的最优关联解,并将这些关联解组合获得最终的关联结果.基于模拟器和标准数据集的仿真实验验证了该关联算法的性能,结果表明该关联算法在保证获得较高关联准确度的同时,大大降低了算法复杂度、缩短了运行时间,适用于解决不同复杂环境中的SLAM数据关联问题. 相似文献
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传统的图像检索方法均是基于图像的局部特征的,忽略了图像整体特征。针对此问题,深入分析图像的整体特征,提出了一种基于局部特征和整体特征的混合方法来提取图像的内容。首先,采用平稳小波变换方法提取图像的水平、垂直和对角线的图像整体信息;其次,应用每个子矩阵的灰度共生矩阵提取图像的局部特征。根据局部特征和整体特征的联合特征描述,应用多模关联规则的数据挖掘方法对图像进行检索,并且其关联规则的主要决定参数为欧几里得距离。实验结果显示,所提出的基于内容的小波变换多模关联规则数据挖掘的图像检索方法相对于已有方案有较大的性能提升。 相似文献
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Tien Dung Do Siu Cheung Hui Fong A.C.M. Fong B. 《Evolutionary Computation, IEEE Transactions on》2009,13(2):217-228
Associative classification (AC), which is based on association rules, has shown great promise over many other classification techniques. To implement AC effectively, we need to tackle the problems on the very large search space of candidate rules during the rule discovery process and incorporate the discovered association rules into the classification process. This paper proposes a new approach that we call artificial immune system-associative classification (AIS-AC), which is based on AIS, for mining association rules effectively for classification. Instead of massively searching for all possible association rules, AIS-AC will only find a subset of association rules that are suitable for effective AC in an evolutionary manner. In this paper, we also evaluate the performance of the proposed AIS-AC approach for AC based on large datasets. The performance results have shown that the proposed approach is efficient in dealing with the problem on the complexity of the rule search space, and at the same time, good classification accuracy has been achieved. This is especially important for mining association rules from large datasets in which the search space of rules is huge. 相似文献
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Mariam Zomorodi‐moghadam Moloud Abdar Zohreh Davarzani Xujuan Zhou Pawel Pawiak U.Rajendra Acharya 《Expert Systems》2021,38(1)
Coronary artery disease (CAD) is one of the major causes of mortality worldwide. Knowledge about risk factors that increase the probability of developing CAD can help to understand the disease better and assist in its treatment. Recently, modern computer‐aided approaches have been used for the prediction and diagnosis of diseases. Swarm intelligence algorithms like particle swarm optimization (PSO) have demonstrated great performance in solving different optimization problems. As rule discovery can be modelled as an optimization problem, it can be mapped to an optimization problem and solved by means of an evolutionary algorithm like PSO. An approach for discovering classification rules of CAD is proposed. The work is based on the real‐world CAD data set and aims at the detection of this disease by producing the accurate and effective rules. The proposed algorithm is a hybrid binary‐real PSO, which includes the combination of categorical and numerical encoding of a particle and a different approach for calculating the velocity of particles. The rules were developed from randomly generated particles, which take random values in the range of each attribute in the rule. Two different feature selection methods based on multi‐objective evolutionary search and PSO were applied on the data set, and the most relevant features were selected by the algorithms. The accuracy of two different rule sets were evaluated. The rule set with 11 features obtained more accurate results than the rule set with 13 features. Our results show that the proposed approach has the ability to produce effective rules with highest accuracy for the detection of CAD. 相似文献
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对于基于特征的开源入侵检测系统Snort来说,如何提高速度以适应高速网络的发展是关键。在分析Snort新特性和现存多种规则匹配方法的基础上,考虑到大量Snort规则在一定时间内只有一小部分规则是活跃的,提出基于活跃规则集的Snort规则匹配方法,通过把每个端口下的规则分成活跃规则集与不活跃规则集,结合反馈规则匹配频度的思想,实时更新规则匹配顺序和控制活跃规则集大小,从而提高规则匹配速度。 相似文献
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Local feature matching is an essential component of many image and object retrieval algorithms. Euclidean and Mahalanobis distances are mostly used in order to quantify the similarity of two stipulated feature vectors. The Euclidean distance is inappropriate in the typical case where the components of the feature vector are incommensurable entities, and indeed yields unsatisfactory results in practice. The Mahalanobis distance performs better, but is less generic in the sense that it requires specific training data. In this paper we consider two alternative ways to construct generic distance measures for image and object retrieval, which do not suffer from any of these shortcomings. The first approach aims at obtaining a (image independent) covariance matrix for a Mahalonobis-like distance function without explicit training, and is applicable to feature vectors consisting of partial image derivatives. In the second approach a stability based similarity measure (SBSM) is introduced for feature vectors that are composed of arbitrary algebraic combinations of image derivatives, and likewise requires no explicit training. The strength and novelty of SBSM lies in the fact that the associated covariance matrix exploits local image structure. A performance analysis shows that feature matching based on SBSM outperforms algorithms based on Euclidean and Mahalanobis distances. 相似文献