Journal of Chongqing Jiaotong University(Natural Science)

Impacts of Weather Factors on Subway Passenger Flow of Beijing

HAN Xili1,2, LUO Yang1

2020, 39(10): 1-4. DOI: 10.3969/j.issn.16740696.2020.10.01

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In order to study the influence rule of weather factors on the passenger flow of subway, based on the daily meteorological data and subway passenger flow data of Beijing from 2016 to 2018, the influence of weather condition, wind force, air quality, extreme high temperature (T>30 ℃), extreme low temperature (T<0 ℃) and other weather factors on the daily subway passenger flow of Beijing was analyzed through SPSS 24 statistics and oneway ANOVA. The results show that under the extreme high temperature weather (T>30 ℃), the daily subway passenger flow of Beijing increases during working days, but does not change significantly on weekends. Under the extreme low temperature weather (T<0℃), the daily subway passenger flow of Beijing decreases during working days and weekends. During working days and weekends, weather condition, wind force, air quality and other factors have no significant influence on the daily subway passenger flow.

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Optimization Algorithm and Implementation of Dispatched Vehicles between Several Flights in Condition of Flights Delay

ZHAO Guihong1, QIN Zhen1, LI Jianfu2

2020, 39(10): 5-9. DOI: 10.3969/j.issn.1674-0696.2020.10.02

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The improper arrangement of apron operation is one of the reasons for airport ground delay. Therefore, it is of great significance to reasonably arrange the operation process and shorten the operation time of the apron. The bionic particle swarm optimization (PSO) algorithm was introduced into the solution of this kind of scheduling problem. Combined with the actual apron operation situation, the overall service time was reduced by reasonably arranging service vehicles. Based on the idea of PSO algorithm, the optimal location of individual vehicle and the global optimal location were studied, and the flights that each vehicle should serve were obtained. Then the service flow of each vehicle could be obtained by sorting the flights. The longest service time of the vehicle was the optimal time of this kind of service vehicle. The mathematical model of vehicle problem was established, and the PSO algorithm was used to solve the problem. The simulation results show that the proposed method is feasible. Through the optimization, the vehicle service time is shortened, and the apron operation time is reduced, which can better guarantee the flight departure on time.

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Intelligent Travel Service Model of Public Transportation under Dynamic Influence of Passenger Flow

LIU Sha, DONG Guofa, LI Xiang, ZENG Xi

2020, 39(10): 10-17. DOI: 10.3969/j.issn.1674-0696.2020.10.03

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Bus is an important means of transportation for urban residents. Being disturbed by the uncertainties of journey time, passenger flow etc., the bus travel often causes delay of passengers. To solve this problem, a reliable bus travel service model was proposed aiming at improving the whole process of bus travel. The proposed model ensured that passengers could arrive at the destination on time and save time effectively. Firstly, the LSTM (Long Short-Term Memory) algorithm was implemented to predict bus journey time, and to provide passengers with target vehicles. Secondly, the influence of dynamic passenger flow on bus travel was taken into consideration. Then, a fuzzy expert system was established to evaluate the passenger flow of public transportation, which was used for planning reasonable departure time and avoiding delay caused by large amount of passenger flow. The passenger flow data in fuzzy expert system was obtained by k-NN algorithm. The actual case shows that the proposed model can provide reliable travel strategy for travelers. The research results have a positive role in promoting bus service level and developing smart travel.

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Coordinated Development of Civil Aviation in Beijing, Tianjin and Hebei Based on the Synergy Model of Composite System

CHU Yanchang, CHEN Feichao, HOU Yunyan

2020, 39(10): 18-23. DOI: 10.3969/j.issn.1674-0696.2020.10.04

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The coordinated development of civil aviation in Beijing, Tianjin and Hebei refers to the coordination and mutual coordination of various civil aviation subsystems in Beijing, Tianjin and Hebei Province, forming a pattern of joint management and differentiated operations. Taking Capital International Airport, Tianjin Binhai International Airport and Shijiazhuang Zhengding International Airport as research objects, the evaluation index system was constructed by using synergy effect and stakeholder theory. Finally, the composite system collaborative model was used to quantitatively measure the coordinated development of the Beijing-Tianjin-Hebei civil aviation system. The results show that, on the one hand, although the overall system synergy is in an “oscillating” upward trend, the overall synergy is still in a low degree of synergy; on the other hand, although the order of each subsystem of Beijing-Tianjin-Hebei civil aviation is constantly increased, each subsystem presents great differences. Among them, the order degree of airlines and airport subsystems has been high, and the air traffic control system has been maintaining a low-speed growth trend.

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Estimation of Waiting Time Value Based on Multi-Logit Model

XIAO Mei1, XU Fubo1, BIAN Haoyi2, YAN Jianqiang3

2020, 39(10): 24-30. DOI: 10.3969/j.issn.1674-0696.2020.10.05

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Waiting time is one of the important factors affecting the attractiveness of public transportation. Waiting time value as the medium of conversion between waiting time and travel cost often has a greater impact on the organizational optimization results of public transportation. The data of willingness to pay (WTP) for travelers to reduce waiting time under different conditions was obtained through research interviews and SP survey methods. Based on the theory of disaggregation, a prediction model of payment behavior based on multinomial Logit model was established. Based on the traveler’s willingness to pay, the value of waiting time under different conditions was calculated by using the prediction results, and the difference of waiting time value under different conditions and its variation rule changing with waiting time length were studied. The results show that the waiting time value is significantly affected by the waiting time length, income level, travel purpose and weather conditions, and it is positively related to waiting time length and income level. The waiting time value of working trip is higher than that of entertainment trip, meanwhile, the waiting time value in bad weather is higher than that in fine weather. In addition, the relationship between the waiting time value and the waiting time length can be well analyzed by Logistic curve, and the fitting coefficient is close to 1.

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Evaluation Method of Driving Level of Urban Rail Transit Drivers Based on Support Vector Machine

LIU Jie

2020, 39(10): 31-36. DOI: 10.3969/j.issn.1674-0696.2020.10.06

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Aiming at the quantitative evaluation of the driving level of rail transit drivers, based on data extraction, data denoising and data dimensionality reduction, an evaluation model of rail drivers driving level based on support vector machine was established and studied. The research results show that the accuracy and stability of SVM model using Gaussian kernel function is better than that of ordinary, linear and polynomial SVM models. Compared with the manual evaluation results, the cosine similarity of SVM model with Gaussian kernel function is higher than 0.98, which indicates the validity of evaluation results of the proposed model.

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Case Study of Shipping Accident Based on MORT

DING Tao1, LIN Zhenchuang1, WANG Fan2, HUANG Zeqian1, WANG Yu1

2020, 39(10): 37-42. DOI: 10.3969/j.issn.1674-0696.2020.10.07

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To control the incidence of shipping accidents and reduce the possibility of public life threats and property losses, the Vessel “Mahedu 104” sunken accident on Aug.16 at Maanshan was analyzed as a case study, by utilizing the management oversight and risk tree (MORT) analysis method, which was based on the theory of systematic causation. Besides, the S-branch and M-branch models of the case study were established by MORT analysis, to scientifically explore the main risk sources of the entire accident occurrence process and the potential danger factors of the existing shipping management system. The corresponding safety management risk factor evaluation index system was determined, and the fuzzy analytic hierarchy process qualitative and quantitative evaluation index was used to quantitatively evaluate the risk factors and find out the main causes of the accident at all levels. This research is of great significance to promote the sustainable development of the shipping economy and improve the safety management level of shipping companies.

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Application of BIM Technology in the Lotus Bridge and Mechanical Properties of Special-Shaped Cable Tower

CHEN Suhua1,2，DING Jianming1,2，JIANG Yanxu2，YU Zhiguang2，LIN Feng2

2020, 39(10): 43-48. DOI: 10.3969/j.issn.1674-0696.2020.10.08

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The BIM technology and parameterized design method were used to study the complex landscape bridge design. Based on Rhinoceros software, the full bridge parameterized BIM model was established. The application of BIM technology in bridge scheme design, structure optimization, design rationality check, engineering quantity statistics and auxiliary design drawing was studied. At the same time, the data docking between the BIM model and the finite element software was realized. And the mechanical properties of the special-shaped cable tower were analyzed emphatically. The research shows that BIM technology and parameterized design are the basis of three-dimensional forward design of bridge, which can effectively control design errors and improve design efficiency and quality in engineering design stage. The mechanical analysis of the special-shaped cable tower shows that the overall stress of the cable tower is mainly under pressure, and the anchorage zone has a relatively higher safety reserve of compressive stress due to the application of circumferential prestress. The stress levels in all directions are within the controllable range. It provides an effective technical route for the application of BIM technology in the design stage of bridge engineering.

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Optimum Design of Stirrup Reinforcement of Ribbed Arch Bridge Considering Randomness of Parameters

LI Xiaogang1，DING Peng1，CHEN Xiaohu1，ZHOU Jianting2，WU Haobo2

2020, 39(10): 49-53. DOI: 10.3969/j.issn.1674-0696.2020.10.09

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Aiming at the problem of quickly and objectively determining the optimal reinforcement scheme of ribbed arch bridge with hoops, the principle of uniform design and efficiency coefficient method was used. Considering the randomness of parameters affecting the reinforcement effect, such as concrete bulk density, reinforcement thickness of both sides, reinforcement thickness of arch back, reinforcement thickness of spandrel and elastic modulus of concrete, the section bearing capacity margin was selected as the evaluation index of reinforcement effect. At the same time, multiple response indexes were integrated into a single index, and the total efficiency coefficient was calculated based on this. According to the judgment of the total efficiency coefficient, the optimal reinforcement scheme was obtained. Meanwhile, combined with the response surface method, the sensitivity analysis of random variables to reinforcement effect was explored. The research results show that: among all the random variables, the thickness of arch back and spandrel is the most sensitive to the reinforcement effect of ribbed arch bridge, and when both of them reach 35%, they should be focused in the design. The sensitive percentage of concrete elastic modulus is only 4%, which can be less considered in the scheme design.

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Lighting Quality of Asymmetric Light Distribution in Highway Tunnels

DING Hao1,2, LIU Peng1, MA Fei2, XIA-Yang Yuyu2, LI Yu1

2020, 39(10): 54-59. DOI: 10.3969/j.issn.1674-0696.2020.10.10

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By using the light intensity of lamps and lanterns to distribute light asymmetrically on the longitudinal section of the road, three kinds of illumination types, such as forward, backward lighting and symmetrical lighting, were formed to explore the illumination quality of asymmetric light distribution in highway tunnels. The contrast method between full-scale test and numerical simulation was used to analyze the lighting efficiency of three types of lighting on cement concrete and asphalt concrete pavement. The main evaluation indexes of lighting quality were average brightness, average illumination, uniformity, STV and TI of road surface. The research results show that when the tunnel pavement is cement concrete, differences in evaluation indicators for all three types of lighting are small. The average brightness difference does not exceed 4.74% of the respective values, the average illuminance difference does not exceed 10.2% of the respective values, and the uniformity difference does not exceed 5.26% of the respective values. When the tunnel pavement is asphalt concrete, the average brightness of the backlight pavement is 96% and 46% higher than that of the forward lighting and symmetrical lighting respectively; the visibility of small targets in backlighting is 2.6 times higher than that in forward lighting and 1.8 times than that in symmetrical lighting; the threshold increment of backlight illumination is higher, but it is still within the acceptable range, and the middle section lighting will not cause great negative impact on driving safety.

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Application of Integrated Geophysical Prospecting Technology in Disease Detection of Operating Karst Tunnels

ZHANG Xiao, YIN Zhanchao, LIU Xiao, DUAN Chonghao, HAO Pengshuai

2020, 39(10): 60-66. DOI: 10.3969/j.issn.1674-0696.2020.10.11

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The Nanshibi Tunnel in Jiangxi province is located in the karst development zone. During the operation period, the water gushing and mud gushing diseases occur every time of seasonal heavy rainfall. The water gushing points are scattered and the water gushing volume is large, which cannot be completely solved by many treatments. Accurate positioning of water source and water guiding channel is the premise of disease control. The integrated detection method was used to detect before the grouting treatment. The water body was located by transient electromagnetic and high-density electric method, and the cave and fault-breaking area were detected by seismic mapping method. The comprehensive geophysical prospecting results were compared and analyzed to determine the spatial location and distribution pattern of the unfavorable geological bodies. The correctness of geophysical prospecting results was verified by the exposure of left hole drilling and grouting line. The research results show that: for operating tunnels in karst areas, the comprehensive use of multiple geophysical prospecting technologies and their mutual confirmation can accurately locate the spatial distribution of water-filled karst caves and water-conducting fissures, which is of guiding significance for the tunnel disease treatment construction.

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High Temperature Rheological Properties of Waterborne Epoxy Emulsified Asphalt

LIU Honghui, LI Xiaojuan

2020, 39(10): 67-73. DOI: 10.3969/j.issn.1674-0696.2020.10.12

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The emulsified asphalt modified by waterborne epoxy resin with different contents was studied. Through the temperature and frequency scanning of dynamic shear rheological test (DSR), the high-temperature rheological properties of 10%, 15%, 20% water-based epoxy resin, 3% SBR composite modified emulsified asphalt and SK90# matrix emulsified asphalt evaporation residue were compared and analyzed to determine the optimal dosage of water-based epoxy resin. The research results show that, in the test temperature range, the complex shear modulus G* of each emulsified asphalt material decreases with increasing temperature and increases with increasing frequency. And the phase angle δ of each emulsified asphalt decreases with the increase of the amount of aqueous epoxy resin. The phase angle δ of the lower content of waterborne epoxy resin and waterborne epoxy/SBR composite modified emulsified asphalt material increases with the increase of temperature and decreases with the increase of frequency. 20% water-based epoxy resin/SBR composite modified emulsified asphalt has the best high temperature deformation resistance and rheological property. The optimum amount of waterborne epoxy resin is 20%.

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Damage Healing Property of Fe2O3-Asphalt Binder

LI Mingxia1, WU Guoxiong1,2,3, LI Xinkai4, ZOU Weiran1, CHENG Yuhang1

2020, 39(10): 74-78. DOI: 10.3969/j.issn.1674-0696.2020.10.13

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In order to explore the self-healing performance of Fe2O3-asphalt binder and its influencing factors, the fatigue-healing-fatigue test of Fe2O3-asphalt binder was carried out by DSR test. And the healing ability of asphalt binder with different Fe2O3 dosage ratios under the conditions of different healing time, different loading strain and different damage degree was studied and analyzed. The research results show that the prolongation of healing time is helpful to the self-healing of Fe2O3-asphalt binder, the increase of damage degree will reduce its healing ability, and different loading strain will also affect the healing performance of Fe2O3-asphalt binder. Under the same healing condition, with the increase of the proportion of Fe2O3 content, the healing rate of Fe2O3-asphalt binder increases at first and then decreases, and the increase and decrease range are related to the proportion of Fe2O3 content. When the dosage ratio of Fe2O3 is 20%, the healing rate of asphalt binder reaches the maximum. When four kinds of healing indexes based on the change of complex modulus of asphalt binder before and after healing are used to evaluate the healing performance, the evolution law of the healing rate of Fe2O3-asphalt binder is consistent under the condition of different Fe2O3 dosage ratio. The healing rate calculated by HI1 healing index formula is generally too large, the healing rate calculated by HI2 healing index formula is generally small, and the healing rate calculated by HI3 and HI4 is close to each other.

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Road Performance of Lime-Modified Yunnan Red Clay Roadbed

XIAO Qingyi, SUN Lidong, FENG Shijie, ZHANG Heng

2020, 39(10): 79-84. DOI: 10.3969/j.issn.1674-0696.2020.10.14

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In order to promote the road construction in Yunnan red clay area and solve the problems of shrinkage cracking when red clay was used as roadbed filler, the lime-modified Yunnan red clay with the mass fraction of 0, 2%, 4%, 6%, 8%, 10% lime was studied. The liquid plastic limit test, compaction test, unconfined compression test, load ratio test and shrinkage test were used to evaluate the engineering properties of the modified red clay. The research results show that when the lime is added to Yunnan red clay for improvement, although the volume shrinkage, shrinkage coefficient and shrinkage limit of Yunnan red clay are slightly increased, the liquid limit, plasticity index and optimum moisture content of red clay are decreased a lot, and the shrinkage cracking of red clay is well restrained. The unconfined compressive strength and CBR of the lime-modified red clay are remarkably improved, and the deformation resistance is enhanced. Comprehensively considering the test results, adding 8% lime in Yunnan red clay can effectively improve the compaction characteristics of red clay, enhance soil strength, inhibit shrinkage cracking, and make it meet the technical requirements of highway subgrade filling.

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Experimental Analysis of Influencing Factors on Ice-Melting of Loop Heat Pipe

ZHOU Shuiwen1, 2, 3, ZHANG Xiaohua1, 2, 3, ZHANG Rong1, 2, 3, ZHAO Kun4, WANG Jianzhuang1,2,3

2020, 39(10): 85-92. DOI: 10.3969/j.issn.1674-0696.2020.10.15

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Influencing factors on ice-melting of loop heat pipe (LHP) was tested and sensitivity coefficients of various factors were calculated based on indoor snowmelt pavement structure model. The influence factors included heating mode, fluid temperature, pipe diameter, pipe distance and heating power. The results show that: LHP has excellent heat transferring effect and the maximum warming rate of road surface can reach 8 ℃/h, while the influence scope is limited at horizontal direction. The heat is continously transported from LHP to road surface and inner pavement. The heat utilization rate of direct electric heating is higher, and the ice thickness only affects the melting time of ice and snow. Road surface is sensitive to heating power and spacing, and 4cm depth is sensitive to fluid temperature and pipe diameter. The heating power sensitivity is the strongest, and the fluid temperature sensitivity is the worst; the thicker the pipe diameter and the larger the spacing, the sensitivity increases.

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Experimental Study on Scour Process for Wide Graded Gravel under Non-constant Flow Process

ZHAO Tianlong1, 2, MA Tingsen1, FU Changjing1, 2, XIAN Cailin1

2020, 39(10): 93-99. DOI: 10.3969/j.issn.1674-0696.2020.10.16

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According to the characteristics of gravel transportation in the process of landslide dam break, three categories of seven groups of wide graded gravel were designed. The first category consisted of two groups of uniform gravel with particle size of 4 mm and 5 mm respectively, and the second one consisted of four groups of non-uniform gravel with maximum particle sizes of 20, 37.5, 53 and 75 mm respectively, and the third one was non-cohesive non-uniform gravel with the maximum particle size of 20 mm. Four groups of test flow conditions including constant flow A and B as well as non-constant flow C and D, and two types of tail-gate opening I and II were selected. A total of 25 groups test conditions were carried out. The flume scour test of wide graded gravel was carried out. The influence rule of discharge process, downstream discharge conditions and grading width of gravel on the scour characteristics of gravel was compared and analyzed. The results show that: for the non-cohesive gravel, the transportation of gravel under non-constant flow is more active than that under constant flow, which is characterized by large scouring and silting. The larger the opening of the tail-gate is, the better the downstream discharge conditions are, the more severe the scouring of gravel is, and the greater the scouring amount is. With the increase of the grading width of gravel, the position of the gravel with the largest scouring depth in the flume is gradually close to the downstream position of the flume, and the scouring amount decreases continuously.

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Model Test Study on Propagation Characteristics of Landslide-Generated Surge along River in Three Gorges Reservoir Area

YUAN Peiyin1, WANG Pingyi2, ZHAO Yü2,3, LI Dongying1

2020, 39(10): 100-104. DOI: 10.3969/j.issn.1674-0696.2020.10.17

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In order to study the propagation characteristics of landslide-generated surge along the river in the Three Gorges Reservoir area, a large-scale reservoir model test was carried out. The reservoir model was divided into four regions: landslide section, straight section, curved section and straight section beyond bend. A total of 25 measuring points were arranged. The variation law of water level h at each measuring point was compared and analyzed. The propagation and attenuation laws of the maximum surge height Hmax and average surge height Hav of the landslide-generated surge along the river were discussed. The results show that with the increase of propagation distance, Hmax and attenuation degree of surge decrease in three regions — landslide section, straight section and straight section beyond bend. The surge height of landslide section is the largest and the attenuation is the fastest, and the other three regions have similar surge height and similar attenuation.

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Assessment of Ecological Environment Quality of Ecological Red Line Area in Northeast Chongqing

GUAN Dongjie, YIN Boling

2020, 39(10): 105-117. DOI: 10.3969/j.issn.1674-0696.2020.10.18

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Delimitation of ecological red line is one of the important measures for ecological environment protection in China. The ecology environment quality of ecological red line area in northeast Chongqing was analyzed and evaluated by using ArcGIS software. Through the construction of eco-environmental quality evaluation index system, the coupling set pair analysis and NPP quantitative index method were used to clarify the stress factors affecting the regional ecological environment quality, and to explore the future protection direction of regional ecological environment. The results show that: the ecological environment quality of the red line area is poor in the center, medium in the south and the center east, favorable in the north of the study area. Ten key indicators, such as the intensity of agricultural activities, have an important impact on the ecological environment quality of the study area. In the future, the ecological environment quality will have a trend of good development in eight areas such as Liangping ecological red line region, and have a declining trend in three areas such as Wanzhou ecological red line region. The ecological environment quality and ecosystem function in different regions of the study area show opposition and identical relationship. The proposed coupling set pair analysis method and NPP model are used to evaluate and predict the importance of regional eco-environmental quality and ecological function services, and the evaluation results accord with the characteristics of regional ecological environment, which can provide reference for the research and improvement of the ecological environment quality in typical areas.

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Lane Departure Identification and Early Warning Method for Autonomous Vehicle

HU Zhengyun1, TONG Qiuhong2, LIU Shuai2

2020, 39(10): 118-125. DOI: 10.3969/j.issn.1674-0696.2020.10.19

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Driverless vehicles need to perceive the environment through the vision system, and lane recognition and monitoring at front is an important part of driving route planning and driving safety monitoring. Aiming at the problem of real-time and adaptability of lane-line image recognition, a lane-line image threshold segmentation optimization algorithm based on the combination of maximum inter-class variance method and genetic algorithmwas proposed. The proposed algorithm determined the first generation population by binary coding, took the maximum inter-class variance calculation formula as the fitness function, and used the variance between classes as the fitness value. The threshold of image segmentation was calculated by genetic algorithm and the image processing was performed by MATLAB programming, which effectively eliminated noise, protected the details of the image and improved the accuracy, fitness and recognition speed of lane-line image recognition. Then, according to the lane-line feature, the lane-line detection and tracking algorithm was used for fitting. The lane departure algorithm was used to judge whether the car deviated from the lane line during the driving process. The proposed algorithm was transplanted to the vehicle image processing chip, and the correctness of the proposed algorithm was verified by real vehicle experiments.Finally,the real-time data of the current lane departure was obtained by the vehicle intelligent terminal and sent to the cloud server.Based on these data, the degree of lane departure was judged and the lane departure warning was realized.The experimental results show that the obtained lane departure data is in good agreement with the actual vehicle driving state at that time.

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Adaptive Control of Active Suspension System with Saturation Nonlinearity

CAO Qingsong, YI Xing, XU Li

2020, 39(10): 126-131. DOI: 10.3969/j.issn.1674-0696.2020.10.20

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The vibration damping performance of active suspension system was seriously restricted by nonlinearity of actuator saturation, which even destabilized the system. The saturation characteristic of system actuator was described by the standard saturation function expression. The dynamic model of active suspension system for 1/4 vehicle body with state feedback of actuator saturation was established, and then the proposed model was transformed into an equation of state with approximate Brunovsky standard. Multi-layer neural network method was used to design the adaptive controller. The adaptive tracking of controller, the robustness of controller under different saturation, the influence of control parameters on the controller and the adaptive effect of controller under random excitation were simulated and studied by using the designed controller. The research results show that the error between output response of system and target value is small, and the controller tracking effect is good. As the saturation decreases, the robustness of system decreases. The selection of control parameters affects the output response of system, and determines the selection range of the main control parameters. The proposed controller still has good adaptive effect under random excitation. This paper can provide some theoretical references for the study on saturation nonlinearity of active suspension system.

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Battery Equalization System with Peaking Shaving and Valley Filling Mode Based on Fuzzy PID Control

LI Jun, HUANG Zhixiang, ZHOU Wei

2020, 39(10): 132-138. DOI: 10.3969/j.issn.1674-0696.2020.10.21

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For the traditional equalization system, the control is complex and the equilibrium speed is slow. Combined with fuzzy control and PID control theory, a fuzzy PID control battery equalization system with peaking shaving and valley filling mode was proposed. The fuzzy PID algorithm was used to modulate the duty cycle (PWM) of the MOS transistors to achieve the optimal control of the equalization current. The equilibrium strategy of the equalization system was analyzed and the working principle of the equalization circuit was verified by establishing the peaking-shaving and valley-filling equalization system. Taking the SOC consistency of the battery as the equilibrium target, the equalization control simulation was carried out under the charging and discharging conditions of the 6-cell lithium-ion battery cells, and compared with the equalization system without fuzzy PID control. The simulation results show that the fuzzy PID control equalization system can reduce the inconsistency between battery packs and significantly shorten the equalization time. During the charging process, the equalization speed is increased by 47.1%; during the discharging process, the equalization speed is increased by 39.7%.

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