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07 July 2023, Volume 42 Issue 6 Previous Issue   
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Transportation+Big Data & Artificial Intelligence

Transportation+Big Data & Artificial Intelligence
Transportation Infrastructure Engineering
Transportation Equipment


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Transportation+Big Data & Artificial Intelligence

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Application of BP Neural to Composite Beam Steel Member Positioning Network Based on Improved Fruit Fly Optimization Algorithm LIU Ping, LIU Weihan, LIANG Dong 2023, 42(6): 1-8.  DOI: 10.3969/j.issn.1674-0696.2023.06.01 Abstract ( )   PDF (3519KB) ( )   In order to improve the installation accuracy of steel members of bridges, an improved BP neural network based on the optimized fruit fly algorithm was established to accurately predict the spatial coordinates of steel members. In the fruit fly algorithm, Logistic mapping was introduced to optimize the initial position of fruit fly population, chaotic dynamic weight and multi-population cooperative search were added to enhance the global search and local exploration ability of the algorithm, which effectively solved the problems of long training time and low accuracy of BP neural network in dealing with complex engineering problems. The improved BP neural network could identify many variables that affected the positioning of steel components and screened out the key variables. Combined with an engineering example of a corrugated steel web-prestressed concrete composite beam low tower cable-stayed bridge, the optimized neural network was used to predict the spatial coordinates of steel web and steel anchor box in the section to be constructed. The research shows that the hole shaft deviation and cable casing deviation of the steel anchor box and corrugated steel web opening connector of the bridge have been greatly improved through the verification of the construction process, which reflects the good application prospect of the improved BP network in accurately predicting the spatial coordinates of steel members. References | Related Articles | Metrics

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Application of Completed Cable Force Optimization of Cable-Stayed Bridge Based on Genetic Algorithm WANG Tao1, HU Yupeng2, ZHANG Xingbiao1, WANG Lu1 2023, 42(6): 9-17.  DOI: 10.3969/j.issn.1674-0696.2023.06.02 Abstract ( )   PDF (1307KB) ( )   In order to study the application of intelligent optimization algorithm in cable force optimization of cable-stayed bridge, genetic algorithm and finite element algorithm were embedded and combined. Based on the self-developed finite element program, a 3D FEM calculation model of the whole large-span cable-stayed bridge for both highway and railway use was established by using rod and beam elements, and the calculation methods of the influence matrix of cable force on the bending moment of each element node were discussed. Two kinds of cable force optimization objective functions were established and solved by using the genetic algorithm toolbox integrated by MATLAB. Meanwhile, the calculation codes which could be directly applied were given, and the difference of optimization results of different objective functions was discussed. Polynomial fitting method was used to adjust the cable force optimization results, and the difference between the calculation results of bridge state with and without considering geometrical nonlinear effect was discussed. The research results show that the intelligent random search based on genetic algorithm can effectively solve the extremum of the objective function related to cable forces and assist bridge designers to obtain the optimal cable forces of cable-stayed bridges. References | Related Articles | Metrics

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Implement Method of Coordinate Correction of Tangent Assembly of Steel Tubular Arch in ANSYS ZHOU Shuixing, ZHOU Linqi, , LIU Zengwu 2023, 42(6): 18-23.  DOI: 10.3969/j.issn.1674-0696.2023.06.03 Abstract ( )   PDF (570KB) ( )   The arch rib of concrete-filled steel tubular arch bridge is mostly installed by segment and segment, and the birth and death element of ANSYS can be used for process analysis. Affected by the virtual displacement of the inactive elements, the segment elements were not activated at the tangent position in ANSYS program. Aiming at the concrete-filled steel tubular arch bridge with truss section, the average displacement of cantilever end node was proposed to be the displacement of the whole section of arch rib to modify the element coordinate before activation, so that it was in the tangent installation position of the previous segment. The calculation formula for coordinate correction was put forward, and the calculation command flow for steel pipe arch installation was compiled, which was used in the construction of concrete-filled steel tubular arch bridge with a span of 320 m. The results show that on the premise of achieving one-time tension of the buckle cable, the error between the measured buckle cable force and the theoretical cable force is within 3%, and the elevation difference between the upstream and downstream arch ribs is controlled within 5 mm. The arch rib shape after arch formation is in good agreement with the self-weight shape of the bare arch. References | Related Articles | Metrics

Transportation+Big Data & Artificial Intelligence

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Safety Monitoring and Assessment of Simply-Supported Hollow Slab Beam Bridge Based on Deflection Monitoring LI Xiaoya1,2，WANG Xuyi1,2，CAO Sugong1,2,3 2023, 42(6): 24-31.  DOI: 10.3969/j.issn.1674-0696.2023.06.04 Abstract ( )   PDF (1295KB) ( )   A single deflection monitoring index was selected, and a formula for calculating the effectiveness coefficient β of long-term deflection monitoring data was proposed, and the deflection sampling frequency f for the short and medium span simply-supported beam bridges was determined. The assessment indexes for hinge joint damage were determined based on the effect of hinge joint damage on the simply-supported hollow slab beam bridges. Both bearing capacity of single beam and a three-level early warning threshold for hinge joint damage were set, and the safety monitoring and assessment were carried out on a simply-supported hollow slab beam bridge. The results show that the mid-span deflection monitoring of a simply-supported hollow slab beam bridge can be used to assess the bearing capacity of single beam and the hinge joint damage; the monitoring value of the mid-span deflection effect of short and medium span simply-supported beam bridges under live load is related to the bridge span, sampling frequency, and driving speed. It is recommended that the sampling frequency of mid-span deflection should be greater than or equal to 9 Hz. The change rate of external load borne by each beam slab can be used to measure the degree of hinge joint damage. The use of a three-level warning mechanism for monitoring and warning of simply-supported hollow slab beam bridges has achieved good results. References | Related Articles | Metrics

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The Accumulated Water Depth Distribution Model of Superelevation Runoff of Highway under Rainstorm Conditions ZHANG Chi1, ZHOU Yuming1, ZHANG Kunlun2, ZHANG Min3 2023, 42(6): 32-39.  DOI: 10.3969/j.issn.1674-0696.2023.06.05 Abstract ( )   PDF (895KB) ( )   Under the rainstorm conditions, the ponding in the superelevation runoff of the highway is easy to cause traffic safety problems. The distribution of accumulated water depth in the superelevation runoff was studied to provide the theoretical guidance for road design. By introducing the Saint-Venant equation and the Manning formula in fluid mechanics, the road geometric model was extracted and the road grid was divided. The finite element method was used to analyze the runoff transfer characteristics and runoff depth between the road grid units, build the distribution model of water accumulation depth in superelevation runoff under rainstorm conditions, and conduct experimental analysis on superelevation runoff of two-way four-lane highway. The results show that the accumulated water depth distribution model can objectively reflect the distribution of ponding depth in the superelevation runoff under different road longitudinal slopes, superelevation cross slopes and rainfall intensities. The research results provide reference and guidance for the linear optimization design of road sections with poor drainage in superelevation runoff. References | Related Articles | Metrics

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Prediction Model of Skid Resistance of Asphalt Pavement Based on Dynamic Friction Behavior of Tire/Road YU Miao1,2, ZHANG Qiang1, SHI Lin3, TANG Oudi1 2023, 42(6): 40-46.  DOI: 10.3969/j.issn.1674-0696.2023.06.06 Abstract ( )   PDF (640KB) ( )   In order to explore the influence rules of pavement texture (macro texture, micro texture), load, speed, slip rate and tire pressure on the friction coefficients of asphalt pavement, the self-developed tire-pavement dynamical friction test system was used to conduct dynamical friction tests on 9 types of rut specimens. The results show that the influence of macro texture on friction coefficient of asphalt pavement is very significant, followed by speed, micro texture and load, and the influence of tire pressure is not significant. Among them, the macro texture is the main factor affecting the friction coefficient, which affects the contact area and stress concentration of tire and road, and the friction coefficient increases with the increase of texture richness. The friction coefficient increases with the increase of slip rate at the initial stage and then tends to be stable. On the contrary, the friction coefficient decreases with the increase of velocity. However, the contribution of tire pressure to the friction coefficient is relatively small. Finally, the prediction model of friction coefficient of asphalt pavement is established combined with BP neural network. References | Related Articles | Metrics

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Road Performance of Inorganic Micro-powder Modified Asphalt and Its Mixture JIA Xiaodong1, 2, LIANG Naixing1, PENG Yiwen3 2023, 42(6): 47-54.  DOI: 10.3969/j.issn.1674-0696.2023.06.07 Abstract ( )   PDF (2366KB) ( )   In order to study the effect of inorganic micro-powder hydrated lime and cement on the road performance of asphalt and its asphalt mixture, the modified asphalt and its mixture were prepared by using the self-developed ultrasonic wind pressure dispersion instrument. Through softening point, penetration, force ductility, scanning electron microscope, freeze-thaw splitting test, low-temperature bending beam test and indirect tensile fatigue test, the influence law of two types and six types of micro-powder on the water stability, low-temperature crack resistance, and fatigue performance of asphalt and its asphalt mixture was analyzed, and the influence mechanism was also analyzed in depth. The research results show that both kinds of inorganic micro-powder can improve the water stability and fatigue performance of the mixture. As the particle size of the micro-powder decreases (the specific surface area increases), the improvement effect of water stability and fatigue performance becomes more obvious. Under the same particle size, the stability of cement water is better than that of hydrated lime, but the fatigue performance is opposite. Two types of micro-powder have adverse effects on the low-temperature performance of asphalt mixtures, but as the particle size decreases, the adverse effects gradually decrease. The adverse effect of hydrated lime on the low-temperature performance of the mixture is smaller than that of cement. References | Related Articles | Metrics

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Steel Slag and Cement Based Geopolymer Solidification of Wet and Soft Loess: Mechanical Properties and Micro Mechanisms CHEN Rui, ZHANG Xing, ZHU Yue 2023, 42(6): 55-61.  DOI: 10.3969/j.issn.1674-0696.2023.06.08 Abstract ( )   PDF (1500KB) ( )   The geopolymer (GP), a low-carbon and environmentally friendly material, was adopted to solidify wet and soft loess. The effects of geopolymer content and age on the strength and deformation of solidified soil were studied through unconfined compression and one-dimensional consolidation tests, and the solidification mechanism was studied through microscopic characteristic analysis, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The experimental results show that the unconfined compressive strength q of solidified soil increases with age, and a prediction formula for the change of q with age is derived. The q of solidified soils increases with GP concentration from 5% to 10%, but the strength slightly decreases when the dosage increases to 20%. When the mixing ratio is 10% and 20%, the compressibility of the solidified soil is significantly reduced, and shows obvious structural characteristics. The hydration products of GP mainly include sodium aluminosilicate hydrate (NASH) and calcium silicate hydrate (CSH) composite gel, and the hydration product content evidently increases with age. The cementing and filling effects of GP can be considered as a chemical structuration, which is the fundamental reason for improving the mechanical properties of the solidified soil. Combined with the macro and micro test results, a mechanism model of geopolymer solidified wet and soft loess is put forward. References | Related Articles | Metrics

Transportation Infrastructure Engineering

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Compaction Characteristics and Particle Crushing Characteristics of Soil-Rock Mixtures with Different Proportions MA Lina1,2, QIAO Danyang1, WANG Qicai1,2, DUAN Yun1, GUO Jie3 2023, 42(6): 62-71.  DOI: 10.3969/j.issn.1674-0696.2023.06.09 Abstract ( )   PDF (943KB) ( )   In order to explore the compaction characteristics of the soil-rock mixture filler and the degree of particle crushing inside the mixture after compaction, the compaction tests with different rock content (P5) and particle crushing tests were carried out indoors. The research results show that, as the P5 content remains unchanged, changing the composition and proportion of fine-grained materials has a more significant impact on the optimal moisture content than the maximum dry density does. The initial rock content of the soil-rock mixture samples with different gradations is the key factor affecting particle crushing. The area enclosed by the particle grading curve before and after compaction can represent the degree of particle size change. The main range of particle size change is 2.5~20 mm, and the degree of particle size change shows a gradually decreasing trend as the particle size decreases. The fractal dimension after compaction has a good fitting relationship with the maximum dry density and the optimal moisture content. The optimal moisture content has a more significant effect on the fractal dimension after compaction than the maximum dry density does. According to the fractal theory, the fractal dimension after compaction is larger than that before compaction, and the difference between the fractal dimension before and after compaction and the crushing index can characterize the particle crushing degree of the mixture in a certain way. The relative fractal dimension of the mixture increases with the increase of the stone content, namely, the greater the relative fractal dimension, the greater the degree of particle crushing. References | Related Articles | Metrics

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Application Practice of MBR Technology in Rural Domestic Sewage Treatment ZHANG Zhanmei1, 2, HUANG Ziran1, ZHANG Zhongtian1, SHI Ruiqi1, REN Xiaoyu1 2023, 42(6): 72-75.  DOI: 10.3969/j.issn.1674-0696.2023.06.10 Abstract ( )   PDF (585KB) ( )   Taking the domestic sewage treatment project in a town of Chongming Island in Shanghai as an example, combined with the local sewage characteristics and geological and topographic characteristics, the domestic sewage treatment system was designed and constructed according to the decentralized treatment mode using the integrated MBR technology. An analysis was conducted on the cost and effluent quality of the integrated MBR domestic sewage treatment system during the operation phase. The cost was analyzed and the effluent quality of the integrated MBR treatment technology was detected during the operation time. The results show that the integrated MBR domestic sewage treatment system not only operates stably, and the effluent quality meets the Class A standard of GB18918-2002 Pollutant Discharge Standard for Urban Sewage Treatment Plants, but also has a small footprint, less maintenance and management workload, and a high degree of automation. References | Related Articles | Metrics

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Effect of the Baffle Sill on Energy Dissipation Characteristics of the Single Open Ditch Located in Ship Lock Chamber CHEN Ming1, MA Xinlin1, DUAN Liming2, HUANG Haijin1 2023, 42(6): 76-83.  DOI: 10.3969/j.issn.1674-0696.2023.06.11 Abstract ( )   PDF (2128KB) ( )   For the filling/empty system of the side branch hole of the long corridor at the bottom of the ship lock, the three-dimensional turbulence flow numerical simulation method was adopted to systematically study the influence characteristics of the dissipating sill on the energy dissipation of a single open ditch in the lock chamber by changing the height of the dissipating sill and the distance between the dissipating sill and the side branch hole. The research results show that the energy dissipation effect after adding a baffle sill within the single open ditch is better than that of without any baffle sills; moreover, when the height of the dissipation sill is half of the height of the side support hole, and the distance between the dissipation sill and the side support hole is 0.4~0.6 times the width of the open ditch, the energy dissipation effect in the lock chamber is better. Meanwhile, the synergistic energy dissipation mechanism of a single open ditch and a dissipation sill is elucidated. References | Related Articles | Metrics

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Mining the Rules of Ships Encountering in Restricted Channel Based on Improved DBSCAN Algorithm ZHANG Xinyu, YAO Yuanxin, QI Zhuang, HUANG Li, YANG Qiong 2023, 42(6): 84-92.  DOI: 10.3969/j.issn.1674-0696.2023.06.12 Abstract ( )   PDF (1724KB) ( )   The encounter situation of ships in restricted channel is complex and changeable. In order to identify the potential navigation risk, a method based on SO-DBSCAN (self-optimal DBSCAN) algorithm to mine the ship encounter laws in restricted channel was proposed. Firstly, a dynamic ship domain model of restricted channel based on ship speed ratio correction was constructed. Considering the influence of ship safety distance and navigation speed on traffic flow in restricted channel, the Fuji model was improved by introducing ship speed ratio correction factor. Secondly, a method of encounter situation division based on dynamic relative bearing was proposed. According to the requirements of the relevant provisions of the international regulations for preventing collisions at sea, 14 kinds of encounter situations were divided by using the dynamic relative bearing relationship between ships and the navigation speed as guidance. Finally, Silhouette Coefficient and Calinski-Harabasz evaluation indexes were introduced, and the maximum weighted sum was taken as the objective function to independently solve the optimal clustering strategy. By collecting the AIS data of the restricted channel of Tianjin port for example verification, the temporal and spatial rules of encountering were mined, and the hot spots of encountering were identified. The research shows that the encounter frequency of ships in the study area is more frequent in the period of 15:00—17:00, and the encounter critical waters are mainly concentrated in the vicinity of Buoy No.42-No.48 and Buoy No.22-No.32, which are in line with the actual navigation. In general, the proposed method to mine the ship encounter laws in restricted channel based on SO-DBSCAN algorithm can not only solve the problem of complex parameter adjustment based on traditional density clustering algorithm, but also effectively identify the high-risk areas. References | Related Articles | Metrics

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Quantitative Analysis of Carbon Emission from Surrounding Rock Support in Highway Tunnel Construction and Research on Carbon Reduction Path LI Hongdi, DU Yifan 2023, 42(6): 93-102.  DOI: 10.3969/j.issn.1674-0696.2023.06.13 Abstract ( )   PDF (598KB) ( )   Highway tunnel construction needs to consume energy and materials and emit a large amount of greenhouse gases into the atmosphere. As the main process of highway tunnel construction, surrounding rock support accounts for a large proportion of energy and material consumption, but at present, less attention is paid to the carbon emission of tunnel surrounding rock support and specific carbon reduction methods. Based on this, the calculation caliber and measurement model of carbon emissions were standardized and studied. According to the carbon emission calculation results of tunnel support construction of 40 tunnels with different grades and lengths of surrounding rock, key carbon emission sources were analyzed, and a carbon emission prediction model for tunnel support construction was established thereby. The specific carbon reduction paths including optimizing construction machinery configuration and using recycled materials were proposed. Finally, a case study was conducted to analyze the carbon reduction effect. The research results show that two carbon reduction measures can reduce carbon emissions by up to 7.62% and 24.83%, respectively. References | Related Articles | Metrics

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Urban Traffic Congestion Propagation Model Based on SIS Propagation Theory CHEN Yuting1, YAN Qipeng1, MAO Jiannan1, HUANG Hao1, LIU Lan1,2 2023, 42(6): 103-110.  DOI: 10.3969/j.issn.1674-0696.2023.06.14 Abstract ( )   PDF (703KB) ( )   In order to study the mechanism and characteristics of urban traffic congestion propagation patterns, an urban traffic congestion propagation model was proposed based on SIS propagation theory. Firstly, the identification methods for the traffic status of road sections were determined, and the numerical changes in congestion propagation efficiency and dissipation efficiency under different identification criteria were compared and analyzed. Secondly, the difference of travel time was considered, and the time deviation parameters were added into classical SIS theory. Then, the variation trend of the proportion of congested road sections over time and the relationship between the proportion of congested road sections and their change rate were studied and taken as a basis to describe the characteristics of congestion propagation. Finally, the Chengdu road traffic network was used as the research road network, and the proposed model was calibrated and validated by using real data during morning peak hours. The results show that the proposed model can accurately describe the relationship between the proportion of congested road sections and their change rate. References | Related Articles | Metrics

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Variable One-Way Traffic Control Algorithm in Internet of Vehicles ZHAO Hongzhuan, LI Lin, ZHOU Dan, CHEN Jianpeng, ZHAN Xin 2023, 42(6): 111-118.  DOI: 10.3969/j.issn.1674-0696.2023.06.15 Abstract ( )   PDF (909KB) ( )   In order to solve the problems of unbalanced traffic flow, unsatisfied traffic demand and irregular time distribution in two-way two-lane scenario, a variable one-way traffic control algorithm was proposed. Taking the traffic density and queue length information obtained from the roadside as constraints, the optimal switching model was formed by using fuzzy control and rolling traffic switching factor method, and the optimal transition clearance scheme for multiple regions of variable road sections was obtained by Q-learning clearance algorithm. The simulation results show that taking 90 s as a detection step size, the switching scheme was real-time acquisitioned and generated, with an accuracy of 91.5%. The transition clearance module generates the optimal clearance scheme for dividing areas according to the real-time status, which reduces the clearance time. When the directional unevenness coefficient is 1.5 and 5.0, compared with the current road network, the overall delay of the road network is reduced by 29.4 % and 25.2 %, the average running speed is increased by 6.8 % and 9.1 %, and the vehicle detour time is reduced by 6.2 % and 7.9 %, which significantly improves the overall service level. References | Related Articles | Metrics

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Calculation Model for the Opening of the Same-Direction Lane Divider at the Entrance of the Expressway WANG Hong，WANG Hongtao，WU Jingan，LI Qilin，ZHU Shunying 2023, 42(6): 119-127.  DOI: 10.3969/j.issn.1674-0696.2023.06.16 Abstract ( )   PDF (803KB) ( )   Based on the existing research on “vehicle and road” factors at home and abroad, the “driver” lane changing behavior factor was added to study the opening of same-direction lane divider at the entrance of the expressway. Based on the drivers psychology and reactions, four lane changing interaction behaviours were proposed: coercion, collaboration, competitive coercion, and competitive collaboration. Four calculation models of the minimum, general, moderate and ideal opening length corresponding to the lane changing behaviour and the clear distance of the opening position in the same-direction lane divider were constructed by the acceptable clearance theory and vehicle kinematics theory. The proposed model was used to calculate reasonable clear distance of opening positions and four types of opening lengths for the “4 to 8” expressway at design speeds of 120 km/h, 100 km/h and 80 km/h. VISSIM and SSAM microscopic traffic simulation software were adopted to simulate and analyze the safety of four types of opening length values and position clear distance values by cluster analysis and fuzzy evaluation methods. The simulation results show that based on the position clearance calculated by the proposed model, there are fewer conflicts at the road section where vehicles entering the highway enter before the same-direction lane divider opening, and the opening position is set reasonably. The minimum opening length of the same-direction lane divider based on coercion lane changing is between critical safety and relatively safe. The opening lengths based on collaboration, competitive coercion, and competitive collaboration are all between relatively safe and safe levels and the security is orderly improved, which shows four types of lengths are basically in line with the minimum, general, moderate and ideal levels. References | Related Articles | Metrics

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Literature Review on Vehicle-Road Cooperative Control Methods at Intersections SUN Lishan1, ZHANG Kangyu1, XU Yan1, WANG Miao1, ZHANG Xin2, KONG Dewen1 2023, 42(6): 128-137.  DOI: 10.3969/j.issn.1674-0696.2023.06.17 Abstract ( )   PDF (693KB) ( )   In order to gain an in-depth understanding of the vehicle-road cooperative control method at the intersection under the intelligent network connection, the development context of the research on the intersection of the vehicle-road cooperative control was systematically reviewed from the perspective of the control method. Firstly, according to the essential characteristics of vehicle-road coordination technology, the basic methods of vehicle-road coordination control were summarized. Secondly, considering the current and future development status and trends of intersection collaborative technology, starting from the type of signal control and the number of collaboratively controlled intersections, the vehicle-road collaborative control methods and their differences at intersections were expounded. In terms of single intersection, the cooperative control characteristics of signalized and non-signaled control intersections were analyzed and the linkage control mechanism between signal lights and vehicles, as well as the time-space conflict resolution method between vehicles and vehicles, vehicles and virtual agents were expounded. In terms of multiple intersections, the advantages of multiple intersections cooperative control were compared and analyzed, and the research progress of multiple intersections cooperative control was summarized from the aspect of balanced regulation of local traffic flow. Finally, the current difficulties of vehicle-road coordination technology at intersections and suggestions for popularization and application were put forward. The research results show that the combing of the current intersection vehicle-road collaborative control method provides a certain guiding reference for the future research, development and evaluation of the intersection collaborative control in the complex, special and transitional stages. References | Related Articles | Metrics

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Approach Sequencing of PMS Under Uncertain Conditions WANG Lili, XIONG Zirui 2023, 42(6): 138-145.  DOI: 10.3969/j.issn.1674-0696.2023.06.18 Abstract ( )   PDF (2304KB) ( )   Aiming at the problem of flight delay propagation caused by the uncertainty of the passing time of the aircraft during the approach, in order to improve the robustness and practicability of the sequencing scheme in actual operation, the static and dynamic sequencing models under uncertain conditions were established based on the point merge system (PMS), respectively, which could hedge the influence of uncertainty. The static sequencing model aimed to minimize the delay time and the maximum flight time of the sequencing side and was optimized by using the improved NSGA-II algorithm combined with random chance constraints. The dynamic sequencing model aimed to minimize the total flight time, and the initial scheme was optimized by heuristic algorithm based on sliding time window. The delay time of the sequencing side of the static and dynamic sequencing models with additional buffers is reduced by 38.8% and 20.8% respectively, compared with the traditional methods. Under the buffer time of 37.5 seconds, the total flight time, the delay time of sequencing side and the maximum flight time of the static sequencing model are reduced by 4%, 19.9% and 7.1% respectively, compared with the dynamic sequencing model. The delay propagation of merge point can be effectively alleviated by losing less operational efficiency. Among them, the static sequencing model changes more in aircraft sequence than the dynamic sequencing model does, and the robust performance of the dynamic sequencing model is better. References | Related Articles | Metrics

Transportation Equipment

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Parameter Optimization of Single-Axle Monorail Vehicle System Based on Multi-objective Collaborative Optimization Algorithm WEN Xiaoxia, GAO Shuang, DU Zixue, YANG Zhen, WU Haoxin 2023, 42(6): 146-154.  DOI: 10.3969/j.issn.1674-0696.2023.06.19 Abstract ( )   PDF (1402KB) ( )   In order to improve the stability of the single-axle monorail vehicle, the structure of the single-axle bogie straddle monorail vehicle with spatial linkage structure was analyzed, and the nonlinear dynamics model of the single-axle monorail vehicle with the spatial linkage structure was established. The sensitivity analysis of the positioning parameters and suspension parameters of the spatial linkage structure of the monorail vehicle to the stability of the single-axle monorail vehicle was carried out by use of the global sensitivity method. Taking the side rolling angle and wheel load reduction rate of the single-axle monorail vehicle body as the target and taking the vehicle curve passing ability as the constraint, the optimization research was conducted on the positioning parameters of the spatial linkage structure and system suspension parameters of a single-axle bogie, which was based on the improved genetic algorithm (NSGA-II). The optimization results show that after the parameter optimization, the side rolling angle of the monorail vehicle body is reduced by 6.695%, and the wheel load reduction rate is reduced by 9.262%, which improves the operation stability of the single-axle monorail vehicle. References | Related Articles | Metrics

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Lane Change Decision and Simulation Verification Based on Fuzzy Reasoning FENG Ying, QIAO Baoshan, JIANG Ziwang, YUAN Xianju 2023, 42(6): 155-162.  DOI: 10.3969/j.issn.1674-0696.2023.06.20 Abstract ( )   PDF (1145KB) ( )   Lane change decision making is an important part in the lane change process of a vehicle. Reasonable decision model can effectively reduce traffic accidents caused by dangerous lane change behavior of vehicles. In order to enable the lane change model to adapt to dynamic traffic road environments, based on the real-time data collected by the NGSIM project of the Federal Highway Administration of the United States Department of Transportation, the relative distance, speed and other relevant characteristic parameters of interactive vehicles during lane change were extracted and analyzed. The dynamic decision model of vehicle lane changing was established based on fuzzy reasoning theory. Through the established Prescan and MATLAB/Simulink co-simulation platform, the NGSIM measured data was used to verify the lane change decision model. The results show that the accuracy of the binary decision lane change model based on fuzzy reasoning reaches 85% and can accurately determine the lane change timing, which can provide a theoretical basis for lane change of intelligent vehicle. References | Related Articles | Metrics