oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
三种未知环境中局部危险避规方法的分析与比较  [PDF]
于宏啸,段建民
北京理工大学学报 , 2012,
Abstract: 以智能车辆在部分或全未知环境中局部危险避规为研究对象,以二维雷达和摄像机为传感器实时检测局部障碍物信息.通过对比分析普通加权、粒子吸引、仿生学筛选方法在触须避规路径选择上的应用,不同方法在规划时间、最优性、平滑度因素对纯避障环境中安全行驶的影响,确定不同环境应用的方法,实车验证了三种算法的正确和有效性,在2010年中国智能车未来挑战赛的单项纯避障环境中,应用该三种算法在不同的环境条件下取得了很好的效果.
dda法和fisher判别法在潜在滑坡判识中的应用比较  [PDF]
李秀珍,王成华,邓宏艳
岩土力学 , 2011,
Abstract: 选择地貌特征(包括地形坡度、沟谷切割状况、洼地封闭状况、前缘临空状况)、滑面特征(包括滑面倾角、滑面形态、滑面阻抗比)、滑体结构和近期活动迹象4大类9个因子作为古(老)滑坡类潜在滑坡的判识指标,以三峡库区和岷江上游地区相同数量的典型滑坡作为学习样本,依据距离判别分析(dda)和fisher线性判别分析(flda)方法,分别建立了两个研究区潜在滑坡的dda判识模型和flda判识模型。实例分析结果表明,dda方法对两个研究区学习样本和测试样本的误判率均为0,而flda方法对两个研究区测试样本的误判率分别为5.56%和11.11%,对学习样本的错判率分别为11.1%和0%。因此,在三峡库区和岷江上游地区潜在滑坡的判识中,dda法比flda法判识准确性更高、适用性更强。
黄河下游畸形河湾形态及裁弯的可行性分析  [PDF]
张林忠,江恩惠,曹永涛,万强
人民黄河 , 2013,
Abstract: ?借助实测资料及模型试验研究成果,分析了黄河下游畸形河湾的形态、成因以及危害,研究了畸形河湾裁弯的可行性.结果表明:在畸形河湾充分发育的河段,在河湾的最窄处裁弯,裁弯比按3~7控制,裁弯成功的几率大,工程效益较高,在这类河段实施“引河法”裁弯是可行的.
基于旋转势场法的双足机器人避障路径规划方法  [PDF]
宋晖,殷国富,李光日
- , 2015, DOI: 10.15961/j.jsuese.2015.05.024
Abstract: 中文摘要: 针对双足机器人在实际环境中运动时难以实时规避障碍物的问题,提出一种基于旋转势场法的避障路径规划方法。该方法将足迹规划思想引入基于势场法的局部实时路径规划中,通过设计新的障碍物旋转势场来解决传统势场法的局部极小值问题,进而利用旋转势场和足迹规划间的映射关系实现双足机器人的实时避障运动。将该算法应用到1台双足机器人上进行实验验证,现场设定障碍物使路径更接近实际作业环境,机器人顺利完成了U型场地的避障,验证了该方法的有效性。
Abstract:Since the biped robots are difficult to avoid obstacles in real time due to the balance constraints when the biped robots walk in actual environments,a path planning and obstacle avoidance method was proposed based on the rotating potential field.First,the idea of footprint planning was introduced into the local real-time path planning based on the potential field.Then,the local minima problem in the traditional potential field was solved by designing a new obstacle rotation potential field and the real-time obstacle avoidance was achieved using the mapping relationship.Finally,the effectiveness of the proposed method was confirmed by obstacle avoidance experiments on a small size biped robot in the environment with U-shaped obstacles
服装二维裁片虚拟模拟技术  [PDF]
朱广舟,李晓久
纺织学报 , 2014,
Abstract: 在三维服装虚拟缝合及试衣过程中,服装2-D裁片虚拟模拟是关键技术之一。应用服装CAD软件绘制服装纸样并存储成DXF格式,通过DXF文件接口程序将纸样载入系统。采用正则栅格法对裁片进行四边形剖分,连接四边形对角线完成对2-D裁片的三角网格化。以三角形顶点为质点、三角形边为弹簧,构建裁片质点-弹簧模型,通过模型受力分析、数值求解完成对2-D裁片的虚拟模拟。以男士背心为例,通过裁片网格剖分实验验证正则栅格法的有效性;同时完成对背心裁片自然下落于桌面和背心虚拟缝合效果模拟。
基于改进势场法的足球机器人避障路径规划  [PDF]
钟碧良,张祺,杨宜民
控制理论与应用 , 2003, DOI: 10.7641/j.issn.1000-8152.2003.4.032
Abstract: 分析了势场法用于移动机器人路径规划中产生目标不可达问题的原因,提出了改进的斥力势场函数,将机器人与目标的相对距离考虑在内,以确保总的势场力在目标位置全局最小.改进的势场法应用于足球机器人避碰控制.仿真与应用结果表明,它能有效地解决在目标附近有障碍物时目标不可达问题.
T2铜板冲裁间隙对冲裁力及断面质量的影响  [PDF]
郑海涛,樊瑜瑾,杨振,郑淮和,唐军
- , 2016, DOI: 10.11951/j.issn.1005-0299.20160611
Abstract: 为提高冲裁件的断面质量和冲裁效率,实现对冲裁间隙的合理优化,现提出了一种新的板料冲裁试验构想:采用广泛应用于变压器等领域板厚为6 mm且相同规格的T2紫铜作为试验材料,通过更换凸模来改变冲裁间隙,完成在不同冲裁间隙条件下对板料的冲裁试验,采集并分析冲裁力随冲裁行程的变化曲线;同时测量光亮带的宽度和最大冲裁力位置,并拟合冲裁力、光亮带宽度等与冲裁间隙之间的曲线.试验表明:冲裁力在塑性变形阶段增大幅度先快后慢,而在此阶段的初期冲裁间隙对冲裁力几乎无影响,但随着冲裁的深入,冲裁间隙越大,冲裁力则越小,当进入断裂带后冲裁力急速下降;对比在相同冲裁间隙条件下冲裁力随冲裁行程的变化曲线和断面质量,可获得冲裁件断面光亮带会随着冲裁力达到最大值时而结束.研究表明,当冲裁间隙为16.67%左右时,光亮带宽度较大且冲裁力较小.
In order to improve the efficiency and cross-sectional quality of punching parts, and achieve a reasonable optimization of punching clearance, now a new sheet metal punching test idea was proposed: the T2 copper with about 6 mm thickness and the same specifications could be used as the test material, which is widely used in transformers and other, by replacing the top die to change the punching clearance, and the punching test for sheet metal under different conditions of punching clearance could be carried out, so punching pressure with the change of the cutting stroke could be collected and analyzed; Measure burnish sectional width and position of maximum punching force simultaneously, and fit curve of both punching force and bright sectional width with the punching clearance. The experimental results show that in stage of plastic deformation the punching force increases rapidly at first then slow down, but in early period of the stage the punching clearance has no effect on the punching force, then with the depth of punching, the greater punching clearance, the smaller punching force, when entering the fault zone the punching force decline dramatically; Compare with section quality and the punching force along with the change of punching trip under the same conditions, that bright cross section will end when the punching force reaches a maximum can be obtained. Research shows that when punching clearance is about 16.77%, the bright sectional width is larger and the punching force is smaller.
基于光流法的视觉避障系统研究
Visual Obstacle Avoidance System Based on Optical Flow Method
 [PDF]

黄宏燕, 高斯文, 余艳梅, 何小海
Journal of Image and Signal Processing (JISP) , 2016, DOI: 10.12677/JISP.2016.52009
Abstract:
本文针对无人机自主飞行过程中有效定位和识别障碍物的问题,研究了基于金字塔Lukas-Kanade光流法的视觉避障原理,在光流法基础上给出了障碍物检测方法及相应的避障策略。结合配有320 × 240像素摄像头的视觉模块和高性能嵌入式计算平台,构建了一套完整的实时视觉避障系统。实验表明,本文算法能够很好地识别障碍物并作出相应的避障动作,具有较好的实时性和鲁棒性。
To solve the problems of effective orientation and obstacle recognition in autonomous flight of Unmanned Aerial Vehicles, this essay has studied the visual obstacle avoidance principle based on Pyramid LK optical flow and the obstacle detection method as well as the relevant obstacle avoidance strategy with the foundation of optical flow. Combining with the 320 × 240 pixle camera- equipped visual module and high-performance embedded computing platform, we constitute a complete real-time visual obstacle avoidance system. Experiments show that the proposed algorithm can recognize obstacle well and react with relevant obstacle avoidance action, which has good real-time and robustness features.
斜裁服装中的省道转移方法  [PDF]
纺织学报 , 2010,
Abstract: 分析了斜裁服装中纸样(衣片)上某个省道转移到同一纸样(衣片)其他部位的方法。有选择地将文化式女上衣原型或斜裁女上衣原型纸样的前、后衣片按侧缝并排摆放,在此基础上建立斜裁框架,然后进行斜裁省道定位和省道转移,最终完成斜裁衣身转移构成。以文化式女上衣原型作为斜裁框架,主要介绍了斜裁服装中最基本的省道转移方法。在斜裁应用实例中,以斜裁女上衣原型作为斜裁框架,通过斜裁锥领花瓣袖女上衣实例分析,介绍进行斜裁省道转移以及完成纸样结构设计等方法。
段玉裁的小学思想和“段学”书目  [PDF]
刘新民
图书情报工作 , 2001,
Abstract: ?介绍段玉裁的生平及其小学思想以及“段学”体系的书目。
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.