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Policy Iteration for Optimal Control of Discrete-Time Time-Varying Nonlinear Systems

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 781-791页

作者： Guangyu Zhu Xiaolu Li Ranran Sun Yiyuan Yang Peng Zhang beijing research Center of Urban Traffic Information Sensing and Service Technologies Key Laboratory of transport Industry of Big Data Application Technologies for Comprehensive transport Beijing Jiaotong UniversityBeijing 100044China transport planning and research institute Ministry of TransportChinaBeijing 100028China

Aimed at infinite horizon optimal control problems of discrete time-varying nonlinear systems,in this paper,a new iterative adaptive dynamic programming algorithm,which is the discrete-time time-varying policy iteration(DTTV)algorithm,is developed.The iterative control law is designed to update the iterative value function which approximates the index function of optimal performance.The admissibility of the iterative control law is analyzed.The results show that the iterative value function is non-increasingly convergent to the Bellman-equation optimal solution.To implement the algorithm,neural networks are employed and a new implementation structure is established,which avoids solving the generalized Bellman equation in each iteration.Finally,the optimal control laws for torsional pendulum and inverted pendulum systems are obtained by using the DTTV policy iteration algorithm,where the mass and pendulum bar length are permitted to be time-varying parameters.The effectiveness of the developed method is illustrated by numerical results and comparisons.

关键词： Adaptive critic designs adaptive dynamic programming approximate dynamic programming optimal control policy iteration time-varying

Optimization of bike-sharing parking spot layout based on usage requirements

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第1期11卷 136-151页

作者： Di Sun Jin Zhou Furong Wan Zhiqiang Sun Xueying Gao College of Urban Rail Transit and Logistics beijing Union University beijing 100101 P.R.China transport planning and research institute Ministry of transport beijing 100028 P.R.China

In this paper,two problems that exist in parking spot layout of bike-sharing which need to be solved are addressed.One is the size of parking spot,while another is the location of parking spot.First,the generation and attraction model of traffic travel is used to predict the usage requirements of bike-sharing,to acquire the parking requirements of bike-sharing.Then,we establish the best station spacing model to calculate the optimal quantity of parking spots.Moreover,the method of shortest distance clustering is applied to cluster the parking demand spots.Finally,the location optimization of bike-sharing parking spot is carried out by using gravity location model.In summary,the layout of bike-sharing parking spot is finished based on the abovementioned four steps.

关键词： Bike-sharing parking spot demand forecast traffic simulation

Effect of organic materials on the chemical properties of saline soil in the Yellow River Delta of China

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Frontiers of Earth Science 2015年第2期9卷 259-267页

作者： Yan YU Jie LIU Chunmeng LIU Shuang ZONG Zhaohua LU School of Chemical and Environmental Engineering China University of Mining and Technology (Beijing) Beijing 100083 China transport planning and research institute Ministry of Transport Beijing 100028 China

A 180-day incubation experiment was con- ducted to investigate the effect of different organic materials on the chemical properties of coastal soil with high salinity and relatively low pH. Four organic materials （three kinds of plant residues： straw, composted straw, and fresh reed; and one kind of poultry manure： chicken manure） were applied at a ratio of 15 g·kg^-1 to samples of costal saline soil from the Yellow River Delta of China. The results showed that the soil pH and exchangeable sodium percentage （ESP） decreased, whereas soil cation exchangeable capacity （CEC） and macronutrient concen- trations increased, regardless of the type of organic material used. All treatments showed a remarkable increase in soil soluble organic carbon （SOC） during the 180-day incubation. The peak values of SOC in descend- ing order were chicken manure, reed, composted straw, straw, and control soil. At the end of incubation, the highest level of SOC occurred in the straw-amended soil, followed by composted straw, reed, and chicken manure- amended soils. Soil respiration rate and available nitrogen were significantly influenced by the type of material used. Although reed-amended soil had a relatively high SOC and respiration rate, the ESP was reduced the least. Consider- ing the possible risk of heavy metals caused by chicken manure, it is proposed that straw and composted straw are the more efficient materials to use for reclaiming costal saline soil and improving the availability of macronu- trients.

关键词： organic material soil organic carbon salt-affected soil ESP respiration rate

基于MFD及实时路况的城市道路机动车排放计算方法

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Atmospheric and Oceanic Science Letters 2020年第2期13卷 89-96页

作者： WANG Kun TONG Yali CAO Tianhui WANG Chenlong WANG Renjie GAO Jiajia LIU Yuan beijing Municipal institute of Labor Protection BeijingChina Environmental Science research&Design institute of Zhejiang Province HangzhouZhejiangChina Transport Planning and Research Institute Beijing BeijingChina China Association of Environmental Protection Industry BeijingChina

本文提出了基于交通流宏观基本图(MFD)以及实时路况数据的城市道路机动车排放计算方法,并以环境保护部发布的指导方法为参照,对所述方法进行了对比验证。以2015年3月北京市五环路高速,国道京福路,省道京周路的氮氧化物排放为例,两种方... 详细信息

本文提出了基于交通流宏观基本图(MFD)以及实时路况数据的城市道路机动车排放计算方法,并以环境保护部发布的指导方法为参照,对所述方法进行了对比验证。以2015年3月北京市五环路高速,国道京福路,省道京周路的氮氧化物排放为例,两种方法计算结果平均偏差分别为?27.7%,?12.9%,?12.0%。因此,基于MFD及实时路况数据对交通流量及机动车排放的估算,可以较好地反映道路机动车的运行情况及排放特征,在构建应用于街区尺度模型的排放清单,城市区域道路机动车排放的时空分布特征等方面具有非常好的应用潜力。

关键词： MFD 交通态势道路类型车型交通监测数据

Cost of non-renewable energy in production of wood pellets in China

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Frontiers of Earth Science 2013年第2期7卷 199-205页

作者： Changbo WANG Lixiao ZHANG Jie LIU State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China transport planning and research institute Ministry of Transport Beijing 100028 China

Assessing the extent to which all bio-fuels that are claimed to be renewable are in fact renewable is essential because producing such renewable fuels itself requires some amount of non-renewable energy （NE） and materials. Using hybrid life cycle analysis （LCA）--from raw material collection to delivery of pellets to end users--the energy cost of wood pellet production in China was estimated at 1.35 J/J, of which only 0.09 J was derived from NE, indicating that only 0.09 J of NE is required to deliver 1 J of renewable energy into society and showing that the process is truly renewable. Most of the NE was consumed during the conversion process （46.21%） and delivery of pellets to end users （40.69%）, during which electricity and diesel are the two major forms of NE used, respectively. Sensitivity analysis showed that the distance over which the pellets are transported affects the cost of NE significantly. Therefore the location of the terminal market and the site where wood resources are available are crucial to saving diesel.

关键词： wood pellet non-renewable energy （NE） hybrid life cycle analysis （LCA） bio-fuel

City level CO_(2) and local air pollutants co-control performance evaluation: A case study of 113 key envir on mental protection cities in China

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Advances in Climate Change research 2022年第1期13卷 118-130页

作者： Qing-Yong ZHANG Bo-Feng CAI Mu-Dan WANG Jun-Xia WANG You-Kai XING Guang-Xia DONG Zhen ZHANG Xian-Qiang MAO School of Environment Beijing Normal University'Beijing 100875China Center for Climate Change and Environmental Policy Chinese Academy of Environmental PlanningBeijing 100012China China National Environmental Monitoring Centre Beijing 100012China Ministry of transport Transport Planning and Research InstituteLaboratory of Transport Pollution Control and Monitoring TechnologyBeijing 100028China

‘Co-control',or synergistically reducing CO_(2)and local air polluta nt emissions,is an important strategy for cities to achieve'low carb on'and'blue sky'simultaneously.However,there were few studies to evaluate and compare the level of co-control of CO_(2) and local air pollutants in cities year.The present study proposed qualitative and quantitative methods to evaluate the level of co-control of CO_(2)and three local air pollutant(SO_(2).NOX,and particulate matter PM)emissions in key environmental protection cities in China over two periods(2012-2015 and 2015-2018).Statistical analysis found that,though three local air pollutant emissions positively correlated with CO_(2) emission,no significantly positive correlation was found between local air pollutants emission reductions and CO_(2) emission reductions,indicating that co-control effects were poor in general.By using the co-control effect coordinate system,qualitative evaluation showed that less than half of the sample cities could achieve co-control of the total amount of CO_(2) and local air pollutants.By employing the indicator of emission reduction equivalence(EReq),quantitative evaluation showed that the co-control level of the sample cities improved in 2015-2018 compared with 2012-2015.Further regression analysis showed that,reducing coal consumption and economic development significantly enhanced the co-control performance of the observed cities.The present case study proved that the proposed methods for evaluation and comparison of the city co-control performance works well,and can be used in other countries and regions to promote global cities racing to carbon and local air pollutants co-control.

关键词： Co-control CO_(2)emission reduction Local air pollutant emission reduction:Performance evaluation Key environmental protection cities

Estimation of the Aircraft CO_2 Emissions of China's Civil Aviation during 1960-2009

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Advances in Climate Change research 2012年第2期3卷 99-105页

作者： HE Ji-Cheng XU Yu-Qing Division of Environment and Resources research Transport Planning and Research Institute Ministry of Transport Beijing 100028 China National Climate Center China Meteorological Administration Beijing 100081 China

Based on data collected by Chinese Civil Aviation Statistic Center, the annual CO 2 emissions of aircrafts during 1960-2009 were calculated, and the emission intensity and its dynamic characteristics were analyzed. The results show that the total CO 2 emissions of aircrafts in China increased from 120 × 10 3 t in 1960 to 41.44 × 10 6 t in 2009. The CO 2 emission intensity decreased from 2.9 kg (converted t km) 1 in 1960 to 0.96 kg (converted t km) 1 in 2009 at an average rate of 0.04 kg (converted t km) 1 per year. The average share of CO 2 emissions of aircrafts on the total CO 2 emissions from the sector of transportation, storage and post was 6.6% during 1980-2005, and 0.25% on the total emissions from fossil fuel combustion during 1971-2008.

关键词：二氧化碳排放量民航飞机中国民航碳排放强度平均增长率估计排放总量动态特性

transportation Development Transition in China

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Chinese Geographical Science 2012年第3期22卷 319-333页

作者： JIN Fengjun DING Jinxue WANG Jiao'e LIU Dong WANG Chengjin Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China transport planning and research institute Ministry of Transport Beijing 100028 China

Scientific development is an invaluable asset to a country.Policies and development modes should be carried out based on scientific findings not only in industry,but also in transportation infrastructure construction.Building an integrated transportation system,which is in line with the national requirements of China and supports sustainable socio-economic development,is a key strategic issue related to building a moderately prosperous society and achieving realistic goals of a medium-level developed country.Based on a systematic review of the advances in China's transportation infrastructure over the last 60 years,this paper explores the main drivers of transportation development,including national policy,transportation structure,investment efficiency,and technological innovation.Analysis shows that China's comprehensive transportation infrastructure construction since 1949 can be divided into five stages initiated by these drivers,which correspond to four transition modes:policy transition,structural transition,efficiency transition,and technology transition.The transition path of China's transportation development shows that the dominant factors have changed,and the interval for each transition has shortened.With the implementation of the '12th Five-Year Plan',China's transportation infrastructure construction is showing some new characteristics and facing a new development transition.Finally,this paper analyzes the trends in transportation development in China and concludes that technological innovation will be the main driving force to increase the transportation supply and service area in the future.

关键词：交通运输结构中国交通基础设施建设综合运输体系中等发达国家技术创新综合交通运输交通发展

A recursive model for static empty container allocation

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Frontiers of Computer Science 2011年第4期5卷 486-495页

作者： Zijian GUO Wenyuan WANG Guolei TANG Jun HUANG Faculty of Infrastructure Engineering Dalian University of Technology Dalian 116023 China transport planning and research institute Ministry of Communications Beijing 100028 China

Backlogged empty containers have gradually turned into a serious burden to shipping networks. Empty container allocation has become an urgent settlement issue for the container shipping industry on a global scale. Therefore, this paper proposes an improved immune algorithm based recursive model for optimizing static empty container allocation which integrates with the global maritime container shipping network. This model minimizes the operating and capital costs during container shipping considering 0-1 mixed-integer programming. So an immune algorithm procedure based on a special two- dimensional chromosome encoding is proposed. Finally, computational experiments are performed to optimize a 10-port static empty container shipping system. The results indicate that the proposed recursive model for static empty container allocation is effective in making an optimal strategy for empty container allocation.

关键词： immune algorithm shipping network emptycontainer allocation