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基于有效路形的车辆振动模型 被引量:4
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作者 张韡 魏朗 余强 《交通运输工程学报》 EI CSCD 北大核心 2008年第4期16-19,24,共5页
为了更加有效地分析车辆与路面突起的接触过程,将轮胎简化为刚性圆环,对现有有效路形的定义进行了改进,将有效路形从原有的轮心轨迹转换为轮胎最低点的轨迹,推导了有效路形的一般求解方程,建立了以有效路形作为路面激励输入的2自由度车... 为了更加有效地分析车辆与路面突起的接触过程,将轮胎简化为刚性圆环,对现有有效路形的定义进行了改进,将有效路形从原有的轮心轨迹转换为轮胎最低点的轨迹,推导了有效路形的一般求解方程,建立了以有效路形作为路面激励输入的2自由度车辆振动模型,并进行了车辆平顺性仿真及试验验证。分析结果表明:以有效路形作为路面输入的仿真结果与实车道路试验结果有着良好的一致性,以有效路形为路面输入时,车轴加速度平均相对误差为5.17%,车身加速度平均相对误差为1.71%;以实际路形为路面输入时,车轴加速度平均相对误差为12.93%,车身加速度平均相对误差为28.48%。 展开更多
关键词 汽车工程 有效路形 实际路形 车辆振动模型
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基于激光结构光技术的路形病害检测系统 被引量:1
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作者 史文建 朱毅军 +2 位作者 乔捷 贾永奎 崔来军 《交通科技》 2006年第6期63-65,共3页
从基础原理出发,介绍基于激光结构光技术的路面变形病害检测系统,给出一种快速、准确的路面变形病害的检测方法。具有一定技术实力的单位可以通过文中介绍的原理,自行研发性价比更高的路面变形病害检测系统,全面提升道路病害检测技术,... 从基础原理出发,介绍基于激光结构光技术的路面变形病害检测系统,给出一种快速、准确的路面变形病害的检测方法。具有一定技术实力的单位可以通过文中介绍的原理,自行研发性价比更高的路面变形病害检测系统,全面提升道路病害检测技术,增强企业的核心竞争力。 展开更多
关键词 激光 结构光 路形 车辙 瘸害 养护 CCD检测
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基于加速度计的路形计算方法研究
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作者 赵红毅 《计算机仿真》 CSCD 北大核心 2011年第1期388-391,共4页
传统的路形测量方法测量过程复杂且测量精度低,为了降低路形测量的难度以及提高路形计算的准确性,提出了一种基于加速度计的路形计算方法,主要由2个加速度计、一个激光位移传感器组成的测量系统为硬件条件,以加速度计所检测到的检测梁... 传统的路形测量方法测量过程复杂且测量精度低,为了降低路形测量的难度以及提高路形计算的准确性,提出了一种基于加速度计的路形计算方法,主要由2个加速度计、一个激光位移传感器组成的测量系统为硬件条件,以加速度计所检测到的检测梁纵向加速度信号作为计算机主要输入信号,经过MATLAB软件滤波处理并对其进行二次积分所得到的检测梁纵向位移作为主要计算参数而求得道路的纵断面形状。在真实的道路上进行了验证,结果表明,所求得的路形与实际的路形接近,吻合度较好。计算方法具有结构简单,精度较高等优点,可满足对大多数路面形状的测量需求。 展开更多
关键词 路形 加速度计 激光位移传感器 纵向加速度信号 滤波
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路形和跟车对驾驶行为的影响综述 被引量:1
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作者 刘欢 冷英 《人类工效学》 2018年第1期81-86,共6页
交通事故发生的原因一直是人们关注的问题,导致事故发生的因素是多方面的,其中最重要的原因是驾驶员的驾驶行为,而影响驾驶行为的因素较多,交通环境尤其重要。本文选择交通环境中的路形和是否跟车两个因素,对路形和是否跟车影响驾驶行... 交通事故发生的原因一直是人们关注的问题,导致事故发生的因素是多方面的,其中最重要的原因是驾驶员的驾驶行为,而影响驾驶行为的因素较多,交通环境尤其重要。本文选择交通环境中的路形和是否跟车两个因素,对路形和是否跟车影响驾驶行为的研究进行综述,为提高道路安全提供参考。 展开更多
关键词 路形 跟车 驾驶行为 交通事故 交通安全 交通环境 道路线形 事故预防 交通心理
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使用激光位移传感器的路形测量系统 被引量:1
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作者 凌国相 《国外汽车》 1991年第4期69-73,共5页
高性能的路形测量系统由4个激光位移传感器和一个非接触式的光学速度传感器组成。在路形测量车的行驶方向上,4个激光位移传感器中的任意3个传感器以非等间隔的方式排列,组成4个不同的3-传感器子系统。4个测量子系统具有不同的空间频率... 高性能的路形测量系统由4个激光位移传感器和一个非接触式的光学速度传感器组成。在路形测量车的行驶方向上,4个激光位移传感器中的任意3个传感器以非等间隔的方式排列,组成4个不同的3-传感器子系统。4个测量子系统具有不同的空间频率特性。通过求该系统传递函数的方法可对路形及其路面功率谱进行精确地测量。该系统的输出与车身高度无关,且基本上不受车辆振动的影响。 展开更多
关键词 激光 传感器 路形 测量
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高速路形测定仪的开发及应用研究
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作者 赵济海 王哲人 《中国公路学报》 EI CAS CSCD 北大核心 1993年第A01期37-44,共8页
关键词 路形 激光 位移器 路面不平度
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道路谱测量检测技术研究综述 被引量:20
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作者 段虎明 石峰 +1 位作者 谢飞 张开斌 《电子测量与仪器学报》 CSCD 2010年第1期72-79,共8页
通过回顾近年来车辆工程的设计开发和公路行业的检测监控中,道路谱测量检测技术的理论研究和发展现状,对比分析了近年来这一领域涌现出的多种测量和检测技术的新方法。根据测试原理的不同,分为接触式测量和非接触式测量两大类来介绍。... 通过回顾近年来车辆工程的设计开发和公路行业的检测监控中,道路谱测量检测技术的理论研究和发展现状,对比分析了近年来这一领域涌现出的多种测量和检测技术的新方法。根据测试原理的不同,分为接触式测量和非接触式测量两大类来介绍。接触式道路谱测量方法的优点是测量精度高、重复性好,缺点是测量速度慢,操作复杂,测量时需要进行交通管制。非接触式测量方法优点比较明显,即测量速度快、操作简单、运行效率高,且不影响道路交通的正常运行,缺点是精度相对比较低、误差源多、价格昂贵。最后针对真实路形测量仪器的设计与开发进行了阐述,并对道路谱测量检测技术未来的发展趋势和研究前景进行了探讨。 展开更多
关键词 道路谱 路面不平度 路形 信号测量
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载荷和胎压对轮胎包容特性的影响 被引量:8
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作者 郭孔辉 刘青 丁国峰 《农业工程学报》 EI CAS CSCD 北大核心 1998年第3期53-55,共3页
以弹性滚子接触模型为基础,通过不同载荷与不同胎压下的有效路形仿真,从理论上分析了轮胎载荷和胎压对轮胎包容特性的影响。
关键词 轮胎包容特性 载荷 胎压 有效路形 轮胎
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载荷与径向刚度对机械弹性车轮包容特性的影响 被引量:2
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作者 王强 赵又群 +1 位作者 付宏勋 张彬彬 《农业工程学报》 EI CAS CSCD 北大核心 2016年第13期36-42,共7页
为解决机械弹性车轮在不平路面的冲击振动传递问题,提高车辆行驶平顺性能,该文基于弹性滚子接触模型、有限元分析及试验测试方法对车轮的包容特性及影响因素进行了研究。通过对车轮有效路形的分析,揭示了负荷和径向刚度对车轮包容特性... 为解决机械弹性车轮在不平路面的冲击振动传递问题,提高车辆行驶平顺性能,该文基于弹性滚子接触模型、有限元分析及试验测试方法对车轮的包容特性及影响因素进行了研究。通过对车轮有效路形的分析,揭示了负荷和径向刚度对车轮包容特性的影响规律,并验证了所建模型的可靠性,结果表明:在车轮径向刚度一定的条件下,有效路形幅值随负荷的增加而减小,但有效路形扰动长度随负荷的增加而增大;在负荷一定的条件下,有效路形幅值随车轮径向刚度的增加而增大,扰动长度随之增加而降低。利用有限元模型和台架试验对车轮的低速稳态包容特性进行了分析,得出了车轮垂向动态力学响应随负荷和径向刚度变化的规律,在径向刚度一定的条件下,车轮垂向力响应随负荷的增加由抛物线形过渡到马鞍形,在负荷一定的条件下,车轮垂向力响应随径向刚度的增加而增大,分析结果反映了该车轮实际包容特性的客观规律性。该研究为机械弹性车轮结构优化及整车振动特性分析提供了参考。 展开更多
关键词 轮胎 模型 有限元法 机械弹性车轮 包容特性 有效路形 载荷 径向刚度
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On the beginning of the Japanese Upper Paleolithic:A review of recent archaeological and anthropological evidence
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作者 Hiroyuki SATO Kazuki MORISAKI 《人类学学报》 CSSCI CSCD 北大核心 2024年第3期470-487,共18页
The beginning of the Japanese Upper Paleolithic has mainly been examined using two major models:the Middle Paleolithic evolutionary model within the archipelago and the continental Upper Paleolithic diffusion/migratio... The beginning of the Japanese Upper Paleolithic has mainly been examined using two major models:the Middle Paleolithic evolutionary model within the archipelago and the continental Upper Paleolithic diffusion/migration model.However,recent archeological data from Japan and nearby countries are challenging such simple models.This paper critically reviews previous chronology of the Japanese Paleolithic,including possible Lower and Middle Paleolithic(LP/MP),and attempts to show an alternative model of the beginning of the Japanese Upper Paleolithic.This paper suggests several possible specimens of LP/MP and recommends further geoarchaeological investigation to understand the reliability and cultural relationship between possible LP/MP specimens and the Early Upper Paleolithic(EUP).The start of the Japanese EUP is presently characterized by a flake industry with trapezoids and denticulates around 39-37 kaBP cal on Paleo-Honshu Island,which has partial resemblance with contemporary assemblages in China and the Korean Peninsula,although trapezoids are endemic only to the Japanese EUP and may have derived from the ancestral lithic tradition.Blade technology appeared earliest on Central Paleo-Honshu Island,about 1000 years later than the earliest flake technology.Although blade technology may have originated from the elongated flake technology of the previous period,the sudden simultaneous emergence implies that it diffused from the Korean Peninsula.This paper proposes that blade technology from the Korean Peninsula arrived on the northeastern Paleo-Honshu Island,including the Japan Sea coastal region of western Honshu,rather than the southwest,where flake technology long prospered,due to differences in ecological settings and adaptation strategies between the two regions. 展开更多
关键词 Japanese Archipelago Early Upper Paleolithic migration route TRAPEZOID denticulate blade technology
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车辆多体动力学仿真中的路面模型构造方法的研究 被引量:2
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作者 陈超 魏来生 赵韬硕 《车辆与动力技术》 2012年第1期41-44,共4页
讨论多体动力学仿真软件中车辆试验路面的生成原理及3种具体的三维路面模型的构造方法 .介绍双轨路形计的工作原理,并用其测量了某试验场路面的不平度数据.依据此数据分别利用3种路面模型构造方法建立了所测路面的模型,通过对所建路面... 讨论多体动力学仿真软件中车辆试验路面的生成原理及3种具体的三维路面模型的构造方法 .介绍双轨路形计的工作原理,并用其测量了某试验场路面的不平度数据.依据此数据分别利用3种路面模型构造方法建立了所测路面的模型,通过对所建路面模型的讨论和比较,总结了各建模方法的优点和不足. 展开更多
关键词 多体动力学仿真 越野路面 三维路面模型 三角形单元 路面不平度 路形
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Synthesis and photoluminescence properties of single-crystal ZnO hexagonal pyramids by PEG400-assisted thermal decomposition route 被引量:1
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作者 刘劲松 张朔 +6 位作者 李子全 朱孔军 陈建康 裘进浩 王春花 高雪琴 王莉萍 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2459-2464,共6页
Large-scale synthesis of ZnO hexagonal pyramids was achieved by a simple thermal decomposition route of precursor at 240 oC in the presence of PEG400. The precursor was obtained by room-temperature solid-state grindin... Large-scale synthesis of ZnO hexagonal pyramids was achieved by a simple thermal decomposition route of precursor at 240 oC in the presence of PEG400. The precursor was obtained by room-temperature solid-state grinding reaction between Zn(CH3COO)2-2H2O and Na2CO3. Crystal structure and morphology of the products were analyzed and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results of further experiments show that PEG400 has an important role in the formation of ZnO hexagonal pyramids. Difference between the single and double hexagonal pyramid structure may come from the special thermal decomposition reaction. The photoluminescence (PL) spectra of ZnO hexagonal pyramids exhibit strong near-band-edge emission at about 386 nm and weak green emission at about 550 nm. The Raman-active vibration at about 435 cm-1 suggests that the ZnO hexagonal pyramids have high crystallinity. 展开更多
关键词 ZnO hexagonal pyramids thermal decomposition route formation mechanism photoluminescence property
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Behavior of soil lateral deformation under embankments 被引量:1
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作者 余闯 刘松玉 《Journal of Southeast University(English Edition)》 EI CAS 2005年第1期78-81,共4页
Based on analysis of additional horizontal stress in the soil underembankment load, the behavior of the lateral deformation of the soil along the depth is studied. Theresult shows that the distribution of lateral defo... Based on analysis of additional horizontal stress in the soil underembankment load, the behavior of the lateral deformation of the soil along the depth is studied. Theresult shows that the distribution of lateral deformation along the depth is arch-shaped, whichcorresponds nicely with the observed data. According to this, a new prediction model is establishedto forecast the lateral deformation. The shapes of the model curve with three parameters in themodel a, b and c are presented. The three parameters can easily be determined by three measured data(s_0, 0), (s_1, h_0)and (s_2, 2h_0). This model is applied to study two cases. The comparisonsillustrate that the displacement predicted by the model corresponds nicely with the measured data. 展开更多
关键词 lateral deformation EMBANKMENT PREDICTION additional stress
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EFFECT OF TOOL-PATH ON MILLING ACCURACY UNDER CLAMPING 被引量:5
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作者 郭魂 左敦稳 +2 位作者 王树宏 徐礼林 王珉 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第3期234-239,共6页
To resolve the deformation problem for thin-walled aero-parts in the actual production, this paper simulates the effect of the tool-path on the machining accuracy of the thin-walled frame. The frame is shaped in the p... To resolve the deformation problem for thin-walled aero-parts in the actual production, this paper simulates the effect of the tool-path on the machining accuracy of the thin-walled frame. The frame is shaped in the part milling under a given clamping condition by using the three-dimensional finite element method (FEM). Result shows that the sidewall deformation has a big difference if only the tool-path changes. When the tool-path from the outside to the inside is used, the machining deformation is smaller than another three kinds of toolpaths. Simulation results are compared with experimental data, and the correctness of the simulation is verified.Reasonable processing paths can be found by FEM. 展开更多
关键词 finite element method tool-path machining accuracy DEFORMATION
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A Fully Integrated CMOS Readout Circuit for Particle Detectors 被引量:2
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作者 张雅聪 陈中建 +2 位作者 鲁文高 赵宝瑛 吉利久 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第2期182-188,共7页
Novel schemes for a charge sensitive amplifier (CSA) and a CR-(RC), semi-Gaussian shaper in a fully integrated CMOS readout circuit for particle detectors are presented. The CSA is designed with poly-resistors as ... Novel schemes for a charge sensitive amplifier (CSA) and a CR-(RC), semi-Gaussian shaper in a fully integrated CMOS readout circuit for particle detectors are presented. The CSA is designed with poly-resistors as feedback components to reduce noise. Compared with conventional CSA, the input referred equivalent noise charge(ENC) is simulated to be reduced from 5036e to 2381e with a large detector capacitance of 150pF at the cost of 0.5V output swing loss. The CR-(RC),semi-Gaussian shaper uses MOS transistors in the triode region in series with poly-resistors to compensate process variation without much linearity reduction. 展开更多
关键词 charge sensitive amplifier SHAPER readout circuit noise optimization
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Effect of processing route on grain refinement in pure copper processed by equal channel angular extrusion 被引量:2
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作者 唐超兰 李豪 李赛毅 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第7期1736-1744,共9页
An experimental study of the microstructures in pure copper billets processed by 8 passes of equal channel angular extrusion (ECAE) via an extended range of processing routes with a 90° die is carried out. Each... An experimental study of the microstructures in pure copper billets processed by 8 passes of equal channel angular extrusion (ECAE) via an extended range of processing routes with a 90° die is carried out. Each processing route is defined according to the inter-pass billet rotation angle (χ), which varies from 0° to 180°. According to the generation of high-angle boundaries and reduction of grain size by electron backscatter diffraction (EBSD) measurements, the grain refinement is found to be most efficient for route with χ=90°and least efficient with χ=180°, among the seven routes studied. This trend is supported by supplementary transmission electron microscopy (TEM) measurements. Comparison of the EBSD and TEM data reveals the importance of considering the non-equiaxity of grain structures in quantitative assessment of microstructural differences in ECAE-processed materials. 展开更多
关键词 pure copper equal channel angular extrusion severe plastic deformation strain path grain refinement
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A Radial Stub Test Circuit for Microwave Power Devices 被引量:2
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作者 罗卫军 陈晓娟 +3 位作者 梁晓新 马晓琳 刘新宇 王晓亮 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第9期1557-1561,共5页
With the principles of microwave circuits and semiconductor device physics, two microwave power device test circuits combined with a test fixture are designed and simulated, whose properties are evaluated by a paramet... With the principles of microwave circuits and semiconductor device physics, two microwave power device test circuits combined with a test fixture are designed and simulated, whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz. The simulation and experimental results verify that the test circuit with a radial stub is better than that without. As an example, a C-band AlGaN/GaN HEMT microwave power device is tested with the designed circuit and fixture. With a 5.4GHz microwave input signal,the maximum gain is 8.75dB,and the maximum output power is 33.2dBm. 展开更多
关键词 radial stub test circuit GAN HEMT
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New Methods to Solve Fuzzy Shortest Path Problems 被引量:3
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作者 刘春林 何建敏 施建军 《Journal of Southeast University(English Edition)》 EI CAS 2001年第1期18-21,共4页
This paper discusses the problem of finding a shortest path from a fixed origin s to a specified node t in a network with arcs represented as typical triangular fuzzy numbers (TFN). Because of the characterist... This paper discusses the problem of finding a shortest path from a fixed origin s to a specified node t in a network with arcs represented as typical triangular fuzzy numbers (TFN). Because of the characteristic of TFNs, the length of any path p from s to t , which equals the extended sum of all arcs belonging to p , is also TFN. Therefore, the fuzzy shortest path problem (FSPP) becomes to select the smallest among all those TFNs corresponding to different paths from s to t (specifically, the smallest TFN represents the shortest path). Based on Adamo's method for ranking fuzzy number, the pessimistic method and its extensions - optimistic method and λ combination method, are presented, and the FSPP is finally converted into the crisp shortest path problems. 展开更多
关键词 triangular fuzzy number fuzzy shortest path ranking function
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Fractal features of size distribution of Chinese intercity bus hubs
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作者 姚志刚 周伟 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期626-629,共4页
Size distribution characteristics of intercity bus hubs in China from 1997 to 2(104 were analyzed regarding highway passenger volume as a size index of intercity bus hubs. Yearly fractal dimensions of intercity bus h... Size distribution characteristics of intercity bus hubs in China from 1997 to 2(104 were analyzed regarding highway passenger volume as a size index of intercity bus hubs. Yearly fractal dimensions of intercity bus hub sizes were exactly calculated by a novel model. Fractal dimensions of the 200 biggest intercity bus hubs from 2000 to 2004 were 1. 486 2 to 1. 511 8, and that is consistent with fractal dimensions of Chinese urban system sizes. It showed that the size distribution of intercity bus hubs had fractal structure. Fractal dimensions from 1997 to 2004 indicated that intercity bus hub size distribution grew from bi-fractal to single fractal. It is concluded that the intercity bus hub system is in evolutionary progress, and the Central Government should support large intercity bus hubs more to optimize system structure. 展开更多
关键词 intercity bus hub FRACTAL size distribution fractal dimension
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Robot coverage algorithm under rectangular decomposition environment
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作者 张赤斌 颜肖龙 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期188-191,共4页
The environment modeling algorithm named rectangular decomposition, which is composed of cellular nodes and interleaving networks, is proposed. The principle of environment modeling is to divide the environment into i... The environment modeling algorithm named rectangular decomposition, which is composed of cellular nodes and interleaving networks, is proposed. The principle of environment modeling is to divide the environment into individual square sub-areas. Each sub-area is orientated by the central point of the sub-areas called a node. The rectangular map based on the square map can enlarge the square area side size to increase the coverage efficiency in the case of there being an adjacent obstacle. Based on this algorithm, a new coverage algorithm, which includes global path planning and local path planning, is introduced. In the global path planning, uncovered subspaces are found by using a special rule. A one-dimensional array P, which is used to obtain the searching priority of node in every direction, is defined as the search rule. The array P includes the condition of coverage towards the adjacent cells, the condition of connectivity and the priorities defined by the user in all eight directions. In the local path planning, every sub-area is covered by using template models according to the shape of the environment. The simulation experiments show that the coverage algorithm is simple, efficient and adapted for complex two- dimensional environments. 展开更多
关键词 path planning complete coverage algorithm rectangular decomposition
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