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Fabian Walz Sören Hohmann 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(8):1126-1142
ABSTRACTSo far, longitudinal motion control has focused on situations like highway driving, where disturbances of the road profile can be neglected. In this paper, we show how the Two Point Tire Model can be used to derive a novel feed-forward control law for a vehicle's longitudinal motion that considers the effects of the road profile and can complement existing control approaches. For this purpose, we recapitulate the basic model assumptions and equations and briefly discuss how it can be used on arbitrary road profiles. Two approaches for implementation in a real vehicle are presented. Comparisons of these approaches in simulation and to a human driver of an experimental vehicle show that the controller can deal with stepped obstacles of up to 14?cm in height. However, the control performance is essentially limited by the actuator delay and human drivers outperform the controller due to their ability of sensing subtle vehicle motions. The results indicate that the control performance can be further improved by using a preview on the necessary drive torque, which can be provided by the solution that we propose. 相似文献
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This study analyzes consumer preferences for a new incentive program based on a point card to promote green consumption; the study also examines the program’s impact on bus utilization in South Korea. An ex-ante analysis was conducted to examine how consumer behavior can be modified based on varying incentive levels of the point card system. In addition, the effect of the system on consumers’ public transport utilization and resulting CO2 emissions reductions are analyzed. The adoption probability of the point card is forecast at about 93%, and annual CO2 emissions are forecast to decrease by 610 kt CO2. 相似文献
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《铁道标准设计通讯》2017,(4):14-18
针对地面激光扫描仪外业获取的海量线路点云数据,核心解决线路点云的专业化处理与利用问题。结合铁路线路技术特征,进行线路点云预处理研究,主要包括线路点云数据配准、采用基于几何特征的传统分割方法结合CCD影像信息进行线路点云数据分割,再经过除噪平滑处理后,对离散点云数据集进行封装处理,进而为后续正向CAD设计数据的提取提供基础操作模型。提出线路点云可视化对象重构方法,基于离散数据点曲率为主的几何特性估算,初步判定线路主点及变坡点信息,进而在不同主点范围内,通过特征截面的构造获取线数据和面数据。重构的线路点云数据符合正向设计习惯,基于此获得的连续钢轨走行面数据可用做线路几何形位判别指标的基础数据。 相似文献
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为了实现无先验信息、无人工决策干预的船体小组立智能制造,采用机器视觉技术来实现小组立表面特征提取与定位。根据船体小组立智能生产线自动焊接定位的需求,设计对小组立工件激光扫描点云进行识别与提取的机器视觉方法,从降低复杂度和运算时间的角度对算法进行了优化,并开发了相应软件。通过不同小组立工件特征提取与定位实验,验证了本文算法在无先验信息、无人工干预、工件随机摆放条件下的可靠性,表明本文所介绍的机器视觉方法能够适应船体构件种类多、非标准件比例高、装配位置随机的特点,为船体智能制造实现提供支持。 相似文献
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Cities are complex systems, where related Human activities are increasingly difficult to explore within. In order to understand urban processes and to gain deeper knowledge about cities, the potential of location-based social networks like Twitter could be used a promising example to explore latent relationships of underlying mobility patterns. In this paper, we therefore present an approach using a geographic self-organizing map (Geo-SOM) to uncover and compare previously unseen patterns from social media and authoritative data. The results, which we validated with Live Traffic Disruption (TIMS) feeds from Transport for London, show that the observed geospatial and temporal patterns between special events (r = 0.73), traffic incidents (r = 0.59) and hazard disruptions (r = 0.41) from TIMS, are strongly correlated with traffic-related, georeferenced tweets. Hence, we conclude that tweets can be used as a proxy indicator to detect collective mobility events and may help to provide stakeholders and decision makers with complementary information on complex mobility processes. 相似文献
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针对胎架布置过程中耗时耗力,浪费大量物资的问题,提出一种面向船舶分段建造的智能胎架布置坐标快速确定方法。首先,构建船体分段面密度模型,并求解其质心;然后,在胎架轨道和最大支撑载荷的约束条件下,确定胎架最优平面点位坐标;其次,通过拟合船体分段外板的曲面模型,以平面点位坐标及胎架活络头接触角度为条件,确定胎架与外板的接触点;最后,通过坐标换算方法,获取各胎架定位高度,确定胎架布置坐标。 本文选用某典型分段为对象,详细阐述确定胎架布置坐标的确定过程 ,实验结果表明该方法能够减少胎架数量、缩短布置时间。 相似文献
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多机多点牵引道岔同步性研究 总被引:1,自引:0,他引:1
李斌 《铁路通信信号工程技术》2007,4(6):10-12
多点牵引且使用外锁闭的大号码道岔的同步转换要求各牵引点转辙机、外锁闭与道岔尖轨充分协调运动,因此,我们根据道岔各牵引点开口准确地计算相应转辙机动程、外锁闭空动程等相关数据,同时改变转辙机起动顺序,作到六点牵引道岔尖轨基本同步运动。 相似文献
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