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18 September 2019, Volume 38 Issue 09 Previous Issue    Next Issue
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Transport+Big Data and Artificial Intelligence
Bridge & Tunnel Engineering
Highway & Railway Engineering
Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment
Traffic & Transportation Engineering
Vehicle &Electromechanical Engineering


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Transport+Big Data and Artificial Intelligence

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Trajectory Tracking Control of Intelligent Tractor Based on MPC Algorithm YAN Guojun1,2,3, BEN Nengjun1, GU Jianhua1, YANG Yan1 2019, 38(09): 1-6.  DOI: 10.3969/j.issn.16740696.2019.09.01 Abstract ( )   PDF (450KB) ( )   This research focuses on the MPC controller design, which makes unmanned tractors follow the reference trajectory. By linearizing the nonlinear kinematics model of the tractor, the linear variable system was obtained, and the MPC algorithm was used to control the steering of the tractor to achieve the purpose of trajectory tracking. In order to optimize the computation speed of the controller, an adaptive MPC controller was proposed. The predicted horizon of the adaptive MPC controller could automatically adjust itself with the change of the reference trajectory curvature, the adaptive MPC controller could shorten the calculation time and ensure the realtime performance of the control system and ensure the trajectory tracking result. The simulation results show that the trajectory tracking controller effectively tracks the reference trajectory when the tractors speed is 10m / s with a distance error of less than 0.03m, and the heading angle error of less than 0.015rad. References | Related Articles | Metrics

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Mathematical Modeling and Solution of Ship Route Planning in Marine Construction Waters XIE Xinlian, LIU Yi, HE Ao 2019, 38(09): 7-12.  DOI: 10.3969/j.issn.1674-0696.2019.09.02 Abstract ( )   PDF (473KB) ( )   To better plan the ship route in the marine construction waters where lies a great risk for maritime navigation, this paper established a mathematical model with the shortest route length possible as the objective function and non-navigable regional and ship steering angle as the constrained equation route planning, focusing on the specific methods as solutions. To this end, we first split the free navigable area into several convex polygons through link lines by graph theory, then connected their midpoints in the construction waters two by two to form the Maklink route network and, based on this network, used the two-stage optimization method for solution, in which Dijkstra algorithm was used to first find the initial route free of danger and then ant colony algorithm to optimize the route mentioned above so as to get the most desirable one with shortest length and smallest steering angle. References | Related Articles | Metrics

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Optimization of En-Route Network Capacity for Aircraft Performance WANG Lili, WANG Hangchen 2019, 38(09): 13-19.  DOI: 10.3969/j.issn.1674-0696.2019.09.03 Abstract ( )   PDF (780KB) ( )   Owing to the low utilization rate of airspace, lack of quantitative models for managing air traffic flow, congestion of air routes and intersections and capability to deal with emergencies, the system for optimal distribution model was improved from the civil aviation actual operation characteristics of air traffic control. Based on the multi-commodity flow theory, the air traffic flow with different performances was transformed into multi-commodity flow on the network. Meanwhile, a mathematical model considering the three-flow synergy was established and the approximate algorithm to reduce the difficulty was expressed. First, the traffic flows of huge, medium and small aircraft with different performances were considered, and the necessity for distinguishing aircrafts different performances with different flows was explained; second, the cost function of the en-route with flow change, based on en-route length, aircrafts speed and fuel coefficient was defined; third, considering network connectivity, route capacity, controller work load and flow type, multi-commodity flow theory and improved system for the optimal allocation model, in which the total cost in the route network is minimum, were used to establish a mathematical model that considers the three-stream synergy. At the same time, aiming at improving the low efficiency of multi-commodity flow calculation in the Ford-Fulkson algorithm, an approximation algorithm for the phased distribution of air traffic flow was designed according to the characteristics of dynamic changes of route network cost; finally, a numerical example was constructed based on some airspace in the North China Control Zone. The simulation results show that the model can complete the coordination of three traffic flows in real time with a large-scale air traffic flow, and it has a greater efficiency in scale calculation than the traditional algorithm. References | Related Articles | Metrics

Bridge & Tunnel Engineering

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Advances in Shear Strength of Reinforced Concrete Beams Against Size Effect LUO Lin1,2, ZHOU Yincheng2, XIANG Bo2, GONG Zheng2 2019, 38(09): 20-28.  DOI: 10.3969/j.issn.1674-0696.2019.09.04 Abstract ( )   PDF (601KB) ( )   As shear failure mechanism is complicated and size effect theories for reinforced concrete beams are inconsistent, the shear strength of reinforced concrete beams against size effect was reviewed and both theoretical and experimental studies about shear strength of reinforced concrete beams were introduced based on size effect with and without web reinforcements after a summary of several different size effect theories. Based on the existing shear strength test data of reinforced concrete beams collected, it obtained a shear strength test database with 250 data for reinforced concrete beams against size effect. Upon the summary of previous research, the progress and prospect of shear strength of reinforced concrete members on size effect have been analyzed. References | Related Articles | Metrics

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Analysis and Solution to Uneven Force of Prestressed Anchor Cable XING Xiaofei1, SHI Yalong1, SHEN Wenhui2, LU Yingming3 2019, 38(09): 29-33.  DOI: 10.3969/j.issn.1674-0696.2019.09.05 Abstract ( )   PDF (1218KB) ( )   The tensioning process of pre-stressed anchors in Bandar Malaysia north subway station found that some of them were unevenly loaded and as seriously eccentric as with a force of more than 80%, which severely affected the safety of foundation pit supporting structures. Owing to this, the factors causing uneven anchorage force were analyzed, and the adding of a correcting device under the anchor plate was proposed and multiple tensile tests were conducted for verification. The results show that most anchor cables have large uneven forces before the corrective device is installed and the installation of a correcting device effectively reduces the anchor cables uneven force. Finally, combined with the design information of the anchor cables in the station, it is proposed that the maximum eccentric force should exceed no more than 30%. References | Related Articles | Metrics

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Application of Elastic Wave Theory in Simply Supported Deck Slab LIANG Dong1, 2，ZOU Xuan1 2019, 38(09): 34-38.  DOI: 10.3969/j.issn.1674-0696.2019.09.06 Abstract ( )   PDF (540KB) ( )   With the widening of roads and bridges, there still exist the shortcomings in the dynamic vibration equations of the present structures for calculating the non-axial vibration response, so the 2D wave equation, based on the spherical wave equation, was derived from the elastic wave theory used for calculating the vibration of the bridge surface at any point in case of the vehicle-bridge coupling. The results of the model and the 2D wave equation established by the finite element software ANSYS show that the variance between the two is less than 10% and the 2D wave equation can better calculate the vibration response of the non-axial position in a simpler way, making up for what lacks in the classical calculation of the transverse vibration state. References | Related Articles | Metrics

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Research on Signal Filtering Method in GPS Dynamic Observation HUANG Guobin1，TAN Xinglong2 2019, 38(09): 39-44.  DOI: 10.3969/j.issn.1674-0696.2019.09.07 Abstract ( )   PDF (585KB) ( )   Wavelet filtering and EMD filter were applied to the GPS dynamic observation data filtering, and an EMD combined wavelet filtering method was put forward for the applilation of wavelet filtering and spectrum analysis to the EMD decomposition. These three filtering methods were applied to the bridge dynamic monitoring data processing in combination with evaluation index analysis, and calculation results show that the EMD combined wavelet filtering method performs better than the other two. References | Related Articles | Metrics

Highway & Railway Engineering

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Effect of Addition of Graphene Oxide and Graphene on Properties of Cement Mortar YUAN Xiaoya1, ZENG Junjie1, GAO Jun2, XIAO Guilan1 2019, 38(09): 45-50.  DOI: 10.3969/j.issn.1674-0696.2019.09.08 Abstract ( )   PDF (826KB) ( )   Graphene (G) coagulates easily and graphene oxide (GO) as its derivative is highly dispersible in water. When mixed in cement slurry, they can display their own advantages and enhance the latter’s dispersibility. Cement mortar mixed together with G and GO and their mechanical properties and corrosion resistance in sodium sulfate solution were investigated in this study. The results show that the simultaneous addition of G and GO to cement mortar improves the strength of cement mortar. When the mass loading of G and GO is 0.075% and 0.03% respectively, the 28d compressive strength and flexural strengthen of cement mortar increases by 49.34% and 40.21% respectively in comparison with the references. The immersion test in sodium sulfate solution shows that the sulfate resistance of the G/GO-blended cement mortar improves significantly. Scanning electron microscopy (SEM) and photoelectron spectroscopy Analytical (EDS) analysis show that the co-addition of GO and G reduce not only the formation of Aft and Afm in the mortar, but also the content of sulfate and aluminum ions in the sample. The porosity test results show that the co-addition of GO and G effectively reduces the porosity of cement mortar and densifies the internal structure of the resulting mortar. References | Related Articles | Metrics

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Experimental Study of Relationship between Voidage and Permeability Coefficient of Asphalt Mixture YANG Datian1, ZHOU Qian2 2019, 38(09): 51-56.  DOI: 10.3969/j.issn.1674-0696.2019.09.09 Abstract ( )   PDF (820KB) ( )   To study the correlation among voidages and between voidage and permeability coefficient obtained from different test methods of asphalt mixture, such four types as SMA-13, AC-13, AC-16 and AC-20 were selected and their samples of diameter 100 mm and height 50 mm were produced. Saturated surface dry method and vacuum sealing method were used to test their bulk specific gravity and compute their voidages, called Vssd and Vvac respectively, and the effective void ratio Ve was gained. Permeability coefficient k was measured with a flexible wall variable head tester. Linear equation fitting and two-sample equal variance hypothesis were used for Vssd, Vvac and Vc. The results show that there is a strong correlation and significant difference between Vssd and Vvac, and between Vvac and Ve, and that the relationship between voidage and permeability coefficient k is fitted through the exponential function, that is, both have a strong correlation. From the exponential fitting curve, their critical void ratio Vcrit and critical permeability coefficient kcrit are obtained as the evaluation index for asphalt mixture composition design, construction quality control and durability. References | Related Articles | Metrics

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Strain-Dependent Model for Complex Modulus of Asphalt Mixture ZHOU Weifeng 2019, 38(09): 57-62.  DOI: 10.3969/j.issn.1674-0696.2019.09.10 Abstract ( )   PDF (696KB) ( )   Two kinds of asphalt mixture were carried out on the frequency sweep test under different mechanical models by means of simple performance test and M2F trapezoid beam loading facility. The Boltzmann complex modulus model was established by nonlinear least squares fitting, and then the strain-dependent model under different mechanical models was built up by mathematical deduction and numerical fitting based on Boltzmann function. The results show that the strain-dependent model of complex modulus based on Boltzmann function can accurately and effectively describe the influence of temperature, frequency and strain on the complex modulus, and the strain-dependent features of asphalt under various mechanical models are different. References | Related Articles | Metrics

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Application of BIM Technology to Highway Slope SUN Jiancheng, ZHU Shuanghan, JIANG Haopeng 2019, 38(09): 63-67.  DOI: 10.3969/j.issn.1674-0696.2019.09.11 Abstract ( )   PDF (723KB) ( )   Owing to the under development of BIM technology applied to the highway slope and the IFC standard function layer and data transmission rules, the standardized technical routes of highway slope BIM model design, construction, operation and maintenance were given. Combined with the project example, the application of Revit and Civil 3D to the highway slope was compared. Based on different modeling ideas, the research shows that each software has its emphasis on the technical functions of parameter setting, information quantification and model analysis, and the result provides the technical route and technical experience for BIM technology to be applied to Chinas highway slope. References | Related Articles | Metrics

Port & Waterway · Hydraulic & Hydroelectric · Resources & Environment

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Model Test and Analysis of the Navigation Flow Conditions at the Entrance and Connection Areas of Multi-lane Shiplocks LI Xia1,2, ZUO Ning1, PENG Yongqin1 2019, 38(09): 68-73.  DOI: 10.3969/j.issn.1674-0696.2019.09.12 Abstract ( )   PDF (621KB) ( )   For the study of the navigation condition of shiplocks in different sizes and scales in combination with the overall hydraulic model test and ship model test, the flow condition at the entrance and connection areas of double-lane small lock, double-lane big lock and three-lane big lock schemes has been analyzed in terms of flow velocity and pattern. The results show that the hub operation, lock scales and lanes play a significant role: the double-lane small lock has a better navigation flow condition, but with a limited capacity; the three-lane big lock has a slightly worse navigation flow condition but, through optimal scheduling of the flood discharge gate and the power station, can basically meet the navigation requirement while the capacity and flow condition of the double-lane big lock are just in between. References | Related Articles | Metrics

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Study and Simulation of Fine Sediment Behavior in Permanent Backwater Zone of Three Gorges Reservoir XIAO Yi, LI Wenjie, YANG Shengfa 2019, 38(09): 74-80.  DOI: 10.3969/j.issn.1674-0696.2019.09.13 Abstract ( )   PDF (1230KB) ( )   The fine sediment deposition in the permanent backwater zone of the Three Gorges Reservoir has exceeded its predictions made during its design period. A series of laboratory experiments were done on samples of fine sediment from the typical part of Huanghuacheng in the Three Gorges Reservoir. Compared with the 4 existing formulas, an improved incipient velocity function for fine sediment deposit was developed including its influence of water pressure and molecular force, and a 2D hydrodynamic-morphological model for simulating channel evolution processes was improved according to the movement of the physical movement of local fine sand. The proposed velocity formula was considered in calculating fine sediment transport, and the improved 2D numerical model applied in Huanghuacheng. Comparisons between model simulation results and field measurements were in agreement. The result shows that the 2D model can predict fine sediment behavior and assist navigation management decisions in the permanent backwater region mentioned above. References | Related Articles | Metrics

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Deformation Monitoring and Stability Analysis of Excavation Slope SUN Yuan1, TIAN Weiqiang1, LING Dehong1, YANG Qingwen2, YANG Zheng3 2019, 38(09): 81-87.  DOI: 10.3969/j.issn.1674-0696.2019.09.14 Abstract ( )   PDF (1220KB) ( )   Deformation monitoring is an effective method for testing the effect of a retaining slope and forecasting its deforming trend. A protected excavation slope in Guizhou was selected as a sample for a detailed exploration about slope structure. The dates of displacement and underground water level of slope from June 2015 to June 2017 were collected and analyzed. The results indicate that the slope deformation was great after the support began (from June to August 2015) and the rate decreased over time, which means that the slopes strike, rock stratums dip and overburdens thickness had deformed it in addition to the rainfall affecting the underground water level, and that the deformation gradually converged after October 2016, which means that the slope was reaching a stable state. References | Related Articles | Metrics

Traffic & Transportation Engineering

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Influence of Foggy Environment on Expressway Car-following Safety LIU Zhaohui1, YU Chunbin2, WANG Chao1, LI Qian1 2019, 38(09): 88-94.  DOI: 10.3969/j.issn.1674-0696.2019.09.15 Abstract ( )   PDF (556KB) ( )   In order to construct a car-following safety system aimed at the features of expressway traffic flow, the influence of the foggy environment on the car-following model and the establishment of the road safety standard were discussed based on both theoretical and simulation analysis. For theoretical analysis, it started from the fog level judgment, collected the meteorological information from different sections of the expressway by the fog monitoring system, and the fog levels were divided by fuzzy clustering analysis. And then it studied the sections of different fog levels separately. By mainly considering the influence of the visibility on speed and that of the road surface humidity on the friction coefficient, it obtained the relationship, and by the nonlinear fitting method, established the safety distance model of different foggy sections of the expressway. Based on this, it analyzed and obtained the models adaptability according to the running features of the vehicle, and the reference value of driving speed and safety distance on different road sections through the data fusion technology, which provides the theoretical basis for the driver's driving safety; for simulation analysis, it clustered and analyzed the meteorological information by using MATLAB and analyzed the error of the nonlinear fitting result by using Origin. The results indicate that the influence of foggy environment on visibility and humidity is relatively large, and the car-following model under an ideal state will no longer apply, which means the necessity to timely update the vehicle follow-up distance and speed limit and obtain the driving safety theory distance value suitable for different fog levels by modifying the model. References | Related Articles | Metrics

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Study on Driving Risk Measurement for Two-lane Freeway Vehicle Group RONG Ying, WEN Huiying, ZHAO Sheng 2019, 38(09): 95-100.  DOI: 10.3969/j.issn.1674-0696.2019.09.16 Abstract ( )   PDF (469KB) ( )   To find out how local vehicle flow influences road safety, a driving risk measurement was done for two-lane freeway vehicles by means of vehicle group. A method for the range of vehicle-group was proposed to analyze such possible conflicts as lateral collision, side scraping, rear-end collision. Reasonable measurement index for each was selected for the driving-risk measurement model of the two-lane highway based on time-to-collision (TTC) and post encroachment time (PET). The models feasibility was finally confirmed with a case study of VISSIM simulation. The results show that, according to the vehicles lane-changing behaviors, the two-lane vehicle group is not just a merge of the opposite vehicles on a two-lane freeway, that evaluating its driving risk can shorten the check of the potential area, improve its risk identification, and that the risk warning for deviation of running speeds through velocity analysis is far greater than others, which proves the efficiency of the model. References | Related Articles | Metrics

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Prediction of Chinas Car Ownership by Grey Neural Network with Simpson Formula WU Wenqing1, XIA Jie2 2019, 38(09): 101-108.  DOI: 10.3969/j.issn.1674-0696.2019.09.17 Abstract ( )   PDF (556KB) ( )   According to the features of non-linearity and randomness of car ownership data, a grey neural network model with Simpson formula was established to predict Chinas car ownership. First, the formula was employed to construct the background value of classic GM (1,1) for improving prediction accuracy; second, such seven factors of car ownership as total gross national income, per capita gross domestic product, total population, investment in fixed assets, total import and export, steel output and total retail sales of consumer goods were viewed by correlation analysis and then the input of neural network was used for building BP neural network model. To determine the weight of the combined model with the prediction error of grey system and BP neural network, the grey neural network model was constructed. With the comparison among the classic grey GM (1,1), GM (1,1) of Simpson formula, BP neural network, grey neural network, Simpson formula grey neural network model, the results show that grey neural network with Simpson formula has the highest prediction accuracy where the relative error is as low as 3% and the mean square deviation is 3.2780%, which is smaller than grey neural network model and single prediction model. References | Related Articles | Metrics

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Survey of Abnormal Behavior of Marine Vessels TANG Huang, YIN Yong, SHEN Helong 2019, 38(09): 109-115.  DOI: 10.3969/j.issn.1674-0696.2019.09.18 Abstract ( )   PDF (546KB) ( )   As the abnormal behavior detection of marine vessels is of great significance to the safety of maritime navigation, intelligent supervision of sea areas and development plan of harbors, its present methods and achievements, challenges as well as future research direction were defined and summarized. It is urgent that a robust algorithm with high accuracy and high real-time performance be proposed to detect and study their abnormal behavior for the improvement of maritime navigation safety. References | Related Articles | Metrics

Vehicle &Electromechanical Engineering

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Study on Optimization of Dynamic Parameters Based on Side Rolling of Controlled Suspension Monorail Vehicle TANG Fei1， MA Shuai2， LI Yao2, XU Xiaohan3 2019, 38(09): 116-121.  DOI: 10.3969/j.issn.1674-0696.2019.09.19 Abstract ( )   PDF (1247KB) ( )   Aiming at the marked side rolling of the suspension monorail vehicle passing the curve, this paper explores how to control it from the perspectives of vehicle design and system dynamic parameter optimization. It analysed first the vehicles structure to establish its topological structure and dynamic simulation model, then the sensitivity of its system dynamic parameters to filter out those significantly affecting the rolling, and at last, took the system dynamic parameters as optimal design variables, using the vehicle operating stability, curve possibility and stationarity as optimal constraint conditions, applying the NSGA-II genetic algorithm as optimization algorithm, combining the multi body dynamic software (ADAMS) with the multi-objective optimization software (mode FRONTIER) to optimize the vehicles rolling. The optimized solution shows that its rolling angle is reduced by 15.90 %~17.11 % when the stiffness of the air spring, vertical stiffness of the walking wheel and the radial stiffness of the horizontal wheel get optimalized under the given constraint conditions, and its side rolling can be effectively controlled. References | Related Articles | Metrics

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Research of Vehicle Rolling Based on Suspension Decoupling Genetic Control HE Feng1, FENG Zihang1,2, WU Qing3 2019, 38(09): 122-127.  DOI: 10.3969/j.issn.1674-0696.2019.09.20 Abstract ( )   PDF (602KB) ( )   The steering angle of the wheel greatly influences the vehicles side tilt. In order to effectively reduce its roll and vibration, the nine-degree-of-freedom active suspension model and four-wheel road excitation time domain model were established. The differential geometric decoupling method was used to decouple the vehicle suspension system and obtain the state while the second-order system simulation in the feedback controller with genetic algorithm could wholly optimize its second-order coefficients and obtain the optimal solution. The simulation results show that the vehicle root roll angle, vertical acceleration of the suspension and elevation of the pitch angle are greatly attenuated after a comparison between the vehicles suspension and passive suspension in the decoupling genetic control and effectively stabilizes the vehicle. References | Related Articles | Metrics

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Experimental Study on Operating Speed Characteristics of Tractor-semitrailer on Expressway Uphill Section SHU Haibo1,2, SHAO Yiming2 2019, 38(09): 128-132.  DOI: 10.3969/j.issn.1674-0696.2019.09.21 Abstract ( )   PDF (501KB) ( )   A typical six axle tractor-semitrailer was selected as the representative model for the expressway. The operating speed of the train with different initial speeds (80, 90, 100 km/h) and different slope gradients (2.2%, 2.9%, 3.5%) were tested on a Chongqing mountainous expressway, and the rear-end characteristics of the car rear-end tractor-semitrailer were analyzed. The results show that the maximum continuous climbing speed remain the same when the tractor-semitrailer enters the same longitudinal slope section at different initial speeds. On different slopes, when the operating speeds of the vehicle decrease differently, the maximum continuous climbing speeds are different. The greater the gradient, the lower the speed and the smaller the maximum continuous climbing speed. The time of the car rear end tractor-semitrailer shortens with the decrease of the initial speed of the tractor-semitrailer entering the slope, and the slope does not much affect the car rear end tractor-semitrailer. References | Related Articles | Metrics