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BP neural network classification on passenger vehicle type based on GA of feature selection 被引量:2
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作者 秦慧超 胡红萍 白艳萍 《Journal of Measurement Science and Instrumentation》 CAS 2012年第3期251-254,共4页
This paper has concluded six features that belong to passenger vehicle types based on genetic algorithm(GA)of feature selection.We have obtained an optimal feature subset,including length,ratio of width and length,and... This paper has concluded six features that belong to passenger vehicle types based on genetic algorithm(GA)of feature selection.We have obtained an optimal feature subset,including length,ratio of width and length,and ratio of height and length.And then we apply this optimal feature subset as well as another feature set,containing length,width and height,to the network input.Back-propagation(BP)neural network and support vector machine(SVM)are applied to classify the passenger vehicle type.There are four passenger vehicle types.This paper selects 400 samples of passenger vehicles,among which 320 samples are used as training set(each class has 80 samples)and the other 80 samples as testing set,taking the feature of the samples as network input and taking four passenger vehicle types as output.For the test,we have applied BP neural network to choose the optimal feature subset as network input,and the results show that the total classification accuracy rate can reach 96%,and the classification accuracy rate of first type can reach 100%.In this condition,we obtain a conclusion that this algorithm is better than the traditional ones[9]. 展开更多
关键词 genetic algorithm(GA) feature selection back-propagation(BP)network passenger vehicles type
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Benefits of Reducing Air Emissions: Replacing Conventional with Electric Passenger Vehicles 被引量:1
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作者 Ofira Ayalon Bernanda Flicstein Amos Shtibelman 《Journal of Environmental Protection》 2013年第10期1035-1043,共9页
The study estimated the cost of local and global air emissions, and to compare the differences between electric passenger vehicles (EV) and conventional, internal combustion engine (ICE) vehicles. The air emissions we... The study estimated the cost of local and global air emissions, and to compare the differences between electric passenger vehicles (EV) and conventional, internal combustion engine (ICE) vehicles. The air emissions were estimated for the year 2020, for Denmark, France and Israel, because of their significantly different fuel mixes to produce electricity—a high percentage of renewable energy, mainly nuclear energy and high fossil fuels, respectively. Air emissions from electricity production and conventional traffic were calculated for each country and then multiplied by the specific country’s cost of emissions. Subtracting the total cost of electricity production from the total cost of conventional transportation yields the total benefit for each of the economies studied. The environmental benefit, depending on EV penetration rates, was found to be in the range of 7.8 to 133 MEUR/year for Denmark, 94 to1948 MEUR/year for France and only 4 to 82 MEUR/year for Israel, whose energy mix is the most polluting. Our analysis also shows higher potential benefits when replacing passenger car fleets comprising a high percentage of diesel cars with EVs, as well as in highly populated areas. In addition, we quantified the differences between EVs with fixed batteries and the new switch able battery concept (EASYBAT), as part of the EU 7th Framework Program me. The additional electricity demands for the EASYBAT concept are negligible, and therefore, do not change the overall conclusion that the cleaner the electricity energy mix and the higher the penetration of EVs, the higher the environmental benefits achieved. 展开更多
关键词 Air Emissions ELECTRIC vehicles passenger Car Externalities Power Generation Externalities Battery-Switch EASYBAT EU FP7
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Impacts of automated passenger cars on the capacity of a freeway basic section: applicability in the determination of vehicle adjustment factors in mixed traffic
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作者 Sia M.Lyimo Valerian Kwigizile +1 位作者 Jun-Seok Oh Zachary D.Asher 《Digital Transportation and Safety》 2023年第4期298-307,共10页
The highway capacity manual(HCM)provides a formula to calculate the heavy vehicle adjustment factor(fHV)as a function of passenger car equivalent factors for the heavy vehicle(ET).However,a significant drawback is tha... The highway capacity manual(HCM)provides a formula to calculate the heavy vehicle adjustment factor(fHV)as a function of passenger car equivalent factors for the heavy vehicle(ET).However,a significant drawback is that the methodology was established solely based on human-driven passenger cars(HDPC)and human-driven heavy vehicles(HDHV).Due to automated passenger cars(APCs),a new adjustment factor(fAV)might be expected.This study simulated traffic flows at different percentages of HDHVs and APCs to investigate the impacts of HDHVs and APCs on freeway capacity by analyzing their influence on fHV and fAV values.The simulation determined observed adjustment factors at different percentages of HDHVs and APCs(fobserved).The HCM formula was used to calculate(fHCM).Modifications to the HCM formula are proposed,and vehicle adjustment factors due to HDHVs and APCs were calculated(fproposed).Results showed that,in the presence of APCs,while fobserved and fHCM were statistically significantly different,fobserved and fproposed were statistically equal.Hence,this study recommends using the proposed formula when determining vehicle adjustment factors(fproposed)due to HDHVs and APCs in the traffic stream. 展开更多
关键词 Connected and automated vehicles Adjustment factors passenger car equivalent factors Automated passenger cars Freeway operation
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Research on a Multi-grid Model for Passenger Evacuation in Ships 被引量:4
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作者 Miao Chen Duanfeng Han Haipeng Zhang 《Journal of Marine Science and Application》 2011年第3期340-346,共7页
In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices... In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices were used, interaction of force among pedestrians or between pedestrians and constructions was considered, and static floor fields in a multi-level exit environment were simplified into cabin and exit static floor fields. Compared with the traditional cellular automata model, the multi-grid model enhanced the continuity of the passengers'track and the precision of the boundary qualifications. The functions of the dislocation distribution of passengers as well as partial overlap of tracks due to congestion were realized. Furthermore, taking the typical cabin environment as an example, the two models were used to analyze passenger evacuation under the same conditions. It was found that the laws of passenger evacuation simulated by the two models are similar, while the simulation's authenticity and accuracy are enhanced by the multi-grid model. 展开更多
关键词 passengers' evacuation in ships multi-grid model simulation evacuation floor field interaction of force
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Experimental Study on Coupled Motions of Mother Ship Launching and Recovering of Human-Occupied Vehicle in Regular Waves
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作者 Yunsai Chen Liang Ma +1 位作者 Wenyang Duan Peng Liu 《Journal of Marine Science and Application》 CSCD 2020年第1期53-63,共11页
The launching and recovery process of a human-occupied vehicle(HOV)faces more complex wave effects than other types of submersible operations.However,due to the nonlinearity between the HOV and its mother ship,difficu... The launching and recovery process of a human-occupied vehicle(HOV)faces more complex wave effects than other types of submersible operations.However,due to the nonlinearity between the HOV and its mother ship,difficulties occur in theoretically simulating their coupled motion and hydrodynamics.The coupled motion responses and the load under different regular wave conditions are investigated experimentally in this study.The optimized design of the experimental scheme simulated the launching and recovery process of the mother ship and HOV in regular waves.The attitude sensor performed synchronous real-time measurement of the coupled motion between the mother ship and HOV as well as obtained the load data on the coupled motion under different cable lengths.The results show that models in heading waves mainly lead to the vertical motion of the hoisting point.In beam waves,the transverse and vertical motions of the hoisting point occur in a certain frequency of waves.Under the heading and beam wave conditions,the longer the hoisting cable is,the greater the movement amplitude of the submersible is.Moreover,compared with the condition of the beam waves,the hoisting submersible has less influence on the mother ship under the condition of the heading waves.The findings provide theoretical support for the design optimization of the launching and recovery operation. 展开更多
关键词 Human-occupied vehicle Experimental study Launch and recovery Coupled motion response Mother ship Regular wave
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Assessment of Investment Risk in Greek Short Sea Shipping: A Ro-Ro Passenger Ferry Case
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作者 Dimitrios V. Lyridis Panayotis G. Zacharioudakis 《Journal of Shipping and Ocean Engineering》 2012年第1期36-44,共9页
The purpose of this paper is to introduce an innovative methodology in shipping investment evaluation based on simulation of a project cash flow. It concerns a complementary approach to current practices and its aim i... The purpose of this paper is to introduce an innovative methodology in shipping investment evaluation based on simulation of a project cash flow. It concerns a complementary approach to current practices and its aim is to provide more information mainly to ship-owners that consider the feasibility of deploying Ro-Ro Passenger ferries. The paper examines a typical semi-conventional RoPax ferry operating in the Aegean Sea. It addresses important economic, operational and procedural issues concerning risk evaluation. The current status is that risk is a notion still strange to main stakeholders. The Greek practice in performing a feasibility study for a project draws on investor's experience and feeling aided by a preliminary economic study. The main thesis of this paper is that there are alternative techniques to evaluate investment risk and measure profitability of a project. A Monte Carlo simulation in collaboration with a typical Ro-Ro cash-flow model is implemented to reveal the extent of risk and provide a useful tool for the assessment of future investments in Greek Short Sea Shipping. 展开更多
关键词 Greek Short Sea shipping investment risk passenger ferries Ro-Ro feasibility study.
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Development and Missions of Unmanned Surface Vehicle 被引量:73
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作者 严汝建 庞硕 +1 位作者 孙寒冰 庞永杰 《Journal of Marine Science and Application》 2010年第4期451-457,共7页
The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that ope... The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service. 展开更多
关键词 unmanned surface vehicle littoral combat ship surveillance and reconnaissance unmanned combat system mine countermeasures
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A Review of Current Research and Advances in Unmanned Surface Vehicles 被引量:10
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作者 Xiangen Bai Bohan Li +1 位作者 Xiaofeng Xu Yingjie Xiao 《Journal of Marine Science and Application》 CSCD 2022年第2期47-58,共12页
Following developments in artificial intelligence and big data technology,the level of intelligence in intelligent vessels has been improved.Intelligent vessels are being developed into unmanned surface vehicles(USVs)... Following developments in artificial intelligence and big data technology,the level of intelligence in intelligent vessels has been improved.Intelligent vessels are being developed into unmanned surface vehicles(USVs),which have widely interested scholars in the shipping industry due to their safety,high efficiency,and energy-saving qualities.Considering the current development of USVs,the types of USVs and applications domestically and internationally are being investigated.USVs emerged with technological developments and their characteristics show some differences from traditional vessels,which brings some problems and advantages for their application.Certain maritime regulations are not applicable to USVs and must be changed.The key technologies in the current development of USVs are being investigated.While the level of intelligence is improving,the protection of cargo cannot be neglected.An innovative approach to the internal structure of USVs is proposed,where the inner hull can automatically recover its original state in case of outer hull tilting.Finally,we summarize the development status of USVs,which are an inevitable direction of development in the marine field. 展开更多
关键词 Unmanned surface vehicle Maritime supervision Intelligent vessel ship automation level Internal structure shipping industry
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Numerical Simulations of the Performance of Steel Guardrails Under Vehicle Impact 被引量:4
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作者 HAO Hong DEEKS J Andrew WU Chengqing 《Transactions of Tianjin University》 EI CAS 2008年第5期318-323,共6页
Road side barriers are constructed to protect passengers and contain vehicles when a vehicle crashes into a barrier. In general, full-scale crash testing needs to be carried out if a geometrically and structurally equ... Road side barriers are constructed to protect passengers and contain vehicles when a vehicle crashes into a barrier. In general, full-scale crash testing needs to be carried out if a geometrically and structurally equivalent barrier has not previously been proven to meet the requirements of containing the vehicle and dissipating sufficient impact energy for passenger protection. As full-scale crash testing is very expensive, the number of data that can be measured in a test is usually limited, and it may not always be possible to obtain good quality measurements in such a test, a reliable and efficient numerical simulation of crash testing is therefore very useful. This paper presents finite element simulations of a 3-rail steel road traffic barrier under vehicle impact. The performance levels defined in Australian Standards AS5100 Clause 10.5 for these barriers are checked. The numerical simulations show that the barrier is able to meet low performance levels. However, the maximum deceleration is higher than the acceptable limit for passenger protection. If present, a kerb launches the vehicles into the barrier, allowing for the possibility of overriding the barrier under certain circumstances, but it redirects the vehicle and reduces the incident angle, which reduces impact force on the barrier. Further investigation into all common kerb profiles on roads should be carried out, as only one kerb profile is investigated in this study. 展开更多
关键词 vehicle impact steel barrier kerb performance level vehicle containment passenger protection
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Lethe<sup>@</sup>-Udr1 Passenger Sedan Final Proposed Configuration
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作者 Roberto Capata 《Journal of Transportation Technologies》 2011年第4期83-93,共11页
For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of... For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of this choice resides in the opportunity to reduce weight and dimension, in comparison to a traditional In- ternal Combustion Engine (ICE). It’s not possible to use the GT engine directly for the vehicle traction, so the UDR1 HS configuration shows the GT set connected with the electric generator only. The result is that the traction is pure electric. Many efforts are spent in the definition of a generic scientific method to define the correct ratio HD (the Hybridization Degree) between the installed power of the battery pack and that of the GT electric generator which simultaneously guarantee the main life for the battery package and the ca- pacity of the vehicle to complete a common mission (about 15 km - 30 km) without lack of energy or stop. This paper reports all studies carried out and finally proposes a possible configuration (weight distribution, VMU logic control, GT dimensions and power rate, battery package characteristics and so on) for mid term solution in the Italian transport system. 展开更多
关键词 Hybrid vehicle passenger Sedan Components Distribution DEGREE of HYBRIDIZATION VMU LOGIC
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Influences of accumulated mileage and technological changes on emissions of regulated pollutants from gasoline passenger vehicles 被引量:5
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作者 Qingyu Zhang Juwang Fan +5 位作者 Weidong Yang Fang Ying Zhen Bao Yi Sheng Cheng Lin Xuan Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第9期197-206,共10页
In this study, the influences of accumulated mileage (deterioration) and technological changes (emission standards) on emission factors (EFs) of regulated pollutants (CO, HC, and NOx) from gasoline passenger v... In this study, the influences of accumulated mileage (deterioration) and technological changes (emission standards) on emission factors (EFs) of regulated pollutants (CO, HC, and NOx) from gasoline passenger vehicles were investigated based on Inspection and Maintenance (I/M) data using the chassis dynamometer method. The accumulated mileage of passenger vehicles was significantly linearly correlated with vehicle age. For most cases, the average EFs of CO, HC and NOx were significantly linearly correlated with accumulated mileage, indicating that emission deterioration had a significant impact on pollutant EFs. Implemented emission standards markedly influenced the EFs of regulated pollutants, and EFs markedly decreased with progressing emission standards. The present study also compared EFs of regulated pollutants between this study and the International vehicle emission (IVE) model, and marked differences in EFs were seen with variations in emission standards, vehicle types and accumulated mileage; NOx EFs in this study were higher than in the IVE model. The results provide new insight into estimating regulated pollutant emissions using the IVE model. 展开更多
关键词 Gasoline passenger vehicle I/M program Emission factor Emission standard Emission deterioration
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Real-world fuel consumption of light-duty passenger vehicles using on-board diagnostic (OBD) systems 被引量:3
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作者 Xuan Zheng Sheng Lu +5 位作者 Liuhanzi Yang Min Yan Guangyi Xu Xiaomeng Wu Lixin Fu Ye Wu 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2020年第2期207-216,共10页
An increasing discrepancy between real-world and type-approval fuel consumption for light-duty passenger vehicles(LDPVs)has been reported by several studies.Normally,real-world fuel consumption is measured primarily b... An increasing discrepancy between real-world and type-approval fuel consumption for light-duty passenger vehicles(LDPVs)has been reported by several studies.Normally,real-world fuel consumption is measured primarily by a portable emission measurement system.The on-board diagnostic(OBD)approach,which is flexible and offers high-resolution data collection,is a promising fuel consumption monitoring method.Three LDPVs were tested with a laboratory dynamometer based on a type-approval cycle,the New European Driving Cycle(NEDC).Fuel consumption was measured by the OBD and constant-volume sampling system(CVS,a regulatory method)to verify the accuracy of the OBD values.The results of the OBD method and the regulatory carbon balance method exhibited a strong linear correlation(e.g.,R^2=0.906-0.977).Compared with the carbon balance results,the fuel consumption results using the OBD were 7.1%±4.3%lower on average.Furthermore,the real-world fuel consumption of six LDPVs was tested in Beijing using the OBD.The results showed that the normalized NEDC real-world fliel consumption of the tested vehicles was 13%±17%higher than the type-approval-based fuel consumption.Because the OBD values are lower than the actual fuel consumption,using a carbon balance method may result in a larger discrepancy between real-word and type-approval ftiel consumption.By means of the operating mode binning and micro trip methods,a strong relationship(R^2=0.984)was established between the average speed and relative fuel consumption.For congested roads(average vehicle speed less than 25 km/h),the fuel consumption of LDPVs is highly sensitive to changes in average speed. 展开更多
关键词 Fuel consumption LIGHT-DUTY passenger vehicles ON-BOARD DIAGNOSTIC SYSTEMS
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Problems Associated with Evacuation from the Ship in Case of an Emergency Situation
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作者 Dorota H. Lozowicka 《International Journal of Automation and computing》 EI 2006年第2期165-168,共4页
The problems associated with evacuation of people from the ship in an emergency situation are analyzed, especially passenger ships are taken under consideration. The most dangerous accidents requiring evacuation are d... The problems associated with evacuation of people from the ship in an emergency situation are analyzed, especially passenger ships are taken under consideration. The most dangerous accidents requiring evacuation are described. Marine accidents often occur as eliminating all of the hazards to human health and life is still impossible. In every case, the evacuation process from the ship must be taken under consideration. Evacuation route arrangement should provide the possibility of safe departure from danger areas for passengers and crew members. Evacuation routes designed for human interaction within the evacuation process and other important factors are reviewed. Additionally, the method for seeking evacuation time as a function of initial distribution of passengers and evacuation routes choosing is suggested. A genetic algorithm will be used, whilst the calculated evacuation time is connected with a fitness function. Parameters Of evacuation routes topology are coded as non-binary chromosomes. Genetic operators are fitted for such types of problems to avoid receiving infeasible solutions. The objective of the proposed method is to find the evacuation time in worse case scenarios. 展开更多
关键词 passenger ship EVACUATION genetic algorithm.
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Implementation of a flexible Major Vacation Toll-free Program for small passenger vehicles in China
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作者 Meng XU Ziyou GAO 《Frontiers of Engineering Management》 2017年第4期498-499,共2页
On July 24,2012,the State Council of the People’s Republic of China implemented'a toll-free program for small passenger vehicles during major vacations1).In the several months that followed,local governments issu... On July 24,2012,the State Council of the People’s Republic of China implemented'a toll-free program for small passenger vehicles during major vacations1).In the several months that followed,local governments issued implementation articles.The current Major Vacation Tollfree Program for small passenger vehicles(MVTP)pioneers the concept(Xu and Gao,2016),'Benefaction to People.'The current MVTP has received 展开更多
关键词 Implementation of a flexible Major Vacation Toll-free Program for small passenger vehicles in China FLEXIBLE
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Passenger Vehicle Registrations Rallied in February——registrations reflect auto market tendency
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《中国汽车(英文版)》 2007年第4期2-,共1页
Passenger vehicles (including vans) registrations year-on-year increased 42.2% in Feb. 2007, reaching 408,570 units. Due to the reason there was a larger sales period before the past Chinese New Year in late of Februa... Passenger vehicles (including vans) registrations year-on-year increased 42.2% in Feb. 2007, reaching 408,570 units. Due to the reason there was a larger sales period before the past Chinese New Year in late of February, thus Feb. 2007 made a rather different tendency than previous years. The registrations exceeded more than 0.2 million compared with the 展开更多
关键词 MORE passenger vehicle Registrations Rallied in February registrations reflect auto market tendency THAN
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A research into the application of the production capacity of passenger and light commercial vehicles in China
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作者 P.h D. JI Xuehong Auto Industry Development Institute , CATARC 《中国汽车(英文版)》 2007年第6期12-,11,共2页
1. An overall judgment on the situation 2006 saw the rapid growth of passenger vehicles, with the production capacity putting into use rose from less than 70 percent to around 80 percent. That with light commercial ve... 1. An overall judgment on the situation 2006 saw the rapid growth of passenger vehicles, with the production capacity putting into use rose from less than 70 percent to around 80 percent. That with light commercial vehicles was similar too. The situation in 2005 and 2006 showed that there are no evidential overdone production capacity. 展开更多
关键词 A research into the application of the production capacity of passenger and light commercial vehicles in China
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计及安全性与舒适性的智能车辆换道轨迹规划研究
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作者 陈峥 赵文龙 +3 位作者 郭凤香 赵志刚 刘昱 刘永刚 《交通运输系统工程与信息》 EI CSCD 北大核心 2024年第1期55-65,共11页
针对当前智能车辆在换道过程中的安全性以及乘员舒适性问题,本文提出一种基于风险场评估轨迹的二次筛选方法。首先,在Frenet坐标系下,将车辆运动解耦为横向和纵向两个维度,基于五次多项式生成所有横向d-t曲线簇和纵向s-t曲线簇;其次,由... 针对当前智能车辆在换道过程中的安全性以及乘员舒适性问题,本文提出一种基于风险场评估轨迹的二次筛选方法。首先,在Frenet坐标系下,将车辆运动解耦为横向和纵向两个维度,基于五次多项式生成所有横向d-t曲线簇和纵向s-t曲线簇;其次,由车辆的动力学特性和三圆碰撞模型设计轨迹初筛评价函数,选取合格轨迹作为候选轨迹;最后,参考人工势场理论的思想,引入行车过程中风险场的概念,根据换道效率,换道风险值和横、纵向冲击度建立总损失函数评价候选轨迹以进行二次筛选,选取最佳轨迹并完成可视化。为检验算法的可行性,通过搭建双车道的道路环境,设计障碍车不同速度和加速度的多场景进行弯道换道的仿真验证。研究结果表明,本文所提算法能够满足换道的安全性和舒适性需求。同时,在正常换道场景下,乘员在换道过程的97.5%时间处于舒适状态,在紧急避障场景下也能达到平衡安全性与舒适性的目标。 展开更多
关键词 智能交通 换道轨迹规划 风险场 智能车辆 Frenet坐标系 乘员舒适性
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面向客船火灾的人员逃生路径规划研究
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作者 陈立家 陆崔旺 +1 位作者 许毅 汪洋 《武汉理工大学学报(交通科学与工程版)》 2024年第5期999-1004,1010,共7页
文中针对火灾蔓延对人员逃生过程的影响,提出一种客船火灾蔓延条件下基于改进蚁群算法的逃生路径规划算法.根据客船三维模型进行火灾蔓延模拟以掌握火灾蔓延态势,定义逃生人员火灾产物耐受限值进行可逃生区域识别,确定安全逃生节点.引... 文中针对火灾蔓延对人员逃生过程的影响,提出一种客船火灾蔓延条件下基于改进蚁群算法的逃生路径规划算法.根据客船三维模型进行火灾蔓延模拟以掌握火灾蔓延态势,定义逃生人员火灾产物耐受限值进行可逃生区域识别,确定安全逃生节点.引入目标方向改进启发函数,避免陷入局部最优,加入最差蚁群的影响和信息挥发系数自适应化,改进蚁群算法的信息素更新机制.通过安全路径二次优化,减少规划出的路径中多余拐点.结果表明:改进后的蚁群算法可以有效地用于客船发生火灾时人员的逃生路径规划. 展开更多
关键词 客船火灾逃生 路径规划 火灾蔓延 蚁群算法
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大跨度钢-混结合梁悬索桥涡激振动控制指标体系研究
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作者 李永乐 朱金 +2 位作者 万田保 李涵 秦顺全 《桥梁建设》 EI CSCD 北大核心 2024年第2期22-30,共9页
为保证已建桥梁发生涡激振动后桥梁结构的安全以及桥上行车和行人安全,提出综合考虑人员舒适性、结构受力和停车线形三方面的大跨度钢-混结合梁悬索桥涡激振动控制指标体系。该体系包含9项指标,分别为驾乘人员舒适度、驾乘人员晕动症、... 为保证已建桥梁发生涡激振动后桥梁结构的安全以及桥上行车和行人安全,提出综合考虑人员舒适性、结构受力和停车线形三方面的大跨度钢-混结合梁悬索桥涡激振动控制指标体系。该体系包含9项指标,分别为驾乘人员舒适度、驾乘人员晕动症、行人舒适度(狄克曼指标)、加劲梁强度、加劲梁应力、加劲梁挠度、桥面纵坡、竖曲线半径和停车视距。以武汉鹦鹉洲长江大桥为背景,分别计算了“限速”和“封桥”2个交通管制措施下9项指标对应的涡激振动振幅限值。在此基础上,将9项指标对应的涡激振动振幅限值的最小值作为涡激振动限值建议取值。结果表明:当该桥发生低阶竖弯涡激振动(VS1、VAS1)时,涡激振动的控制因素为加劲梁挠度指标;当大桥发生VAS2模态的竖弯涡激振动时,涡激振动由驾乘人员晕动症指标和行人舒适度指标共同控制;当大桥发生高阶竖弯涡激振动(VAS3、VAS4)时,涡激振动由行人舒适度指标控制。涡激振动控制指标体系及限值标准的计算框架可适用于不同桥型涡激振动限值的计算。 展开更多
关键词 悬索桥 钢-混结合梁 涡激振动 控制指标体系 人员舒适性 结构受力 行车线形
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不同坐姿乘员在自动驾驶汽车碰撞中的损伤仿真实验
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作者 武和全 李羿辉 +1 位作者 刘瑾 张申奥 《汽车安全与节能学报》 CAS CSCD 北大核心 2024年第4期484-491,共8页
为研究不同坐姿乘员在自动驾驶汽车中的碰撞安全性,筛选了7种具有代表性的乘员姿态(包括头部、上肢和躯干的变化)进行正面碰撞的仿真实验,对其乘员运动学和所受载荷进行了对比分析,研究其姿态对乘员碰撞损伤的影响。结果表明:在正面碰... 为研究不同坐姿乘员在自动驾驶汽车中的碰撞安全性,筛选了7种具有代表性的乘员姿态(包括头部、上肢和躯干的变化)进行正面碰撞的仿真实验,对其乘员运动学和所受载荷进行了对比分析,研究其姿态对乘员碰撞损伤的影响。结果表明:在正面碰撞仿真实验中,倚靠姿态乘员的综合损伤风险与其他姿态相比更高,较交谈姿态,倚靠姿态乘员胸部压缩量增大了45.5%,肋骨骨折严重,内脏器官应变提高了48.8%,左倾姿态乘员损伤风险则明显降低,其头部损伤风险减少了49.1%,胸部损伤降低了14.4%。基于此,提出乘员在碰撞前可通过调整自身姿态来规避部分损伤的策略,以提高乘员在自动驾驶汽车中的碰撞安全性。 展开更多
关键词 自动驾驶汽车 正面碰撞 仿真实验 乘员损伤风险 乘员非标坐姿
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