Table of Content

25 January 2023, Volume 51 Issue 1

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2023, 51(1):  0. 

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Mechanical Engineering

Strengthening and Toughening Process Method of 30CrMnSiA Thin-Wall Cup-Shaped Parts



XIA Qinxiang, XIE Zhangxiong, CHEN Can, et al

2023, 51(1):  1-7.  doi:10.12141/j.issn.1000-565X.220075

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30CrMnSiA thin-wall cup-shaped part is a key basic component widely used in the flexible gear of harmonic reducer. Aiming at the problem of the low bearing capacity and short service life of harmonic reducer caused by insufficient strength and toughness of 30CrMnSiA thin-wall cup-shaped parts manufactured by traditional turning method, this paper proposed a plastic deformation-heat treatment process which consists of spinning, quenching, tempering, spinning and aging to manufacture 30CrMnSiA thin-wall cup-shaped parts with less or no cutting and excellent mechanical properties. Through the tensile and impact experiment, by comparing the mechanical properties of each process part, the microorganization of each process part was analyzed. The results show that tempered sorbite microstructure with high strength can be obtained by spinning-quenching and tempering process, but the plasticity was reduced significantly. The fibrous microstructure of spun parts can be further refined by aging heat treatment, and the fine carbides precipitated and uniformly distributed on the ferrite matrix. High strength and good plasticity can be obtained by subsequent aging at 300 ℃ for 6 h. As compared with parts obtained by turning forming after quenching and tempering heat treatment, the yield strength and tensile strength of 30CrMnSiA thin-wall cup-shaped parts manufactured by plastic deformation and heat treatment are improved by 93.65% and 47.88%, respectively. The hardness is increased by 26.87%, and the impact strength is increased by 12.01%. Meanwhile, the elongation and percentage reduction of area are 11.60% and 24.64%, respectively. The thin-wall cup-shaped parts with high strength and toughness can be manufactured by the plastic deformation and heat treatment process of spinning-quenching-tempering-spinning-aging, which provides a new method for manufacturing the thin-wall cup-shaped parts with high-strength and toughness.

Design and Experimental Research of Hydraulically Driven Bionic Venus Flytrap Flexible Gripper



LI Jian, WANG Yuhan, WANG Yangwei, et al

2023, 51(1):  8-15.  doi:10.12141/j.issn.1000-565X.220089

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With the development of science and technology and the needs of life, flexible gripper technology has gradually become a research hotspot because of its safety and compliance. As a plant that can realize envelope grasping, the movement characteristics of flytrap grass have strong reference for the grasping movement of flexible grippers. According to the soft mesh structure and the deformation mechanism of the Venus flytrap, this paper proposed a hydraulically driven bionic Venus flytrap flexible gripper structure composed of double bionic blades. Firstly, a mathematical model of the relationship between the bending angle and the pressure of the fully embedded single-column grid was analyzed based on the simulation model, and then the relationship between the bending angle and the pressure of the multi-column grid was analyzed based on the simulation model, and the working pressure of the flexible gripper was determined to be 0.040 MPa. The analysis of simulation results shows that the bending angle change and force of the incomplete edge mesh are greater than that of the complete mesh, which proves that the incomplete mesh is the weak point of the strength of the flexible gripper. The bending experiments and closing force experiments of the hydraulically actuated and pneumatically actuated bionic blades were carried out, and it was proved that the performance of hydraulic actuation was better than that of pneumatic actuation under working pressure, and the ready pressure of the flexible gripper was determined to be 0.010 MPa. Finally, adaptive experiments show that the designed flexible gripper can grasp objects of different shapes, and the maximum load capacity is confirmed to reach 304.3 g. The hydraulically driven bionic Venus flytrap flexible gripper proposed in this paper can provide an effective solution for live insect capture and non-destructive harvesting, as well as a theoretical and technical basis for the research and development of bionic plant robots.

Inverse Kinematics Solution of 5-DOF Manipulator via Joint Angle Parameterization and Feasible Direction of Approach Vector



WAN Zhenping, LUO Zhao, LU Longsheng, et al

2023, 51(1):  16-21.  doi:10.12141/j.issn.1000-565X.220066

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The manipulator with five degrees of freedom (5-DOF) cannot reach any pose, so it is easy to get no solution when the traditional pose description method is used to solve the inverse kinematics. In this paper, a 5-DOF manipulator consisting of four rotary joints and one prismatic joint, which is suitable for cleaning, spraying, welding and other operations, is taken as an example to establish a kinematic model and its inverse kinematic analysis is carried out. Then, an inverse kinematics solution method based on joint angle parameterization combined with the feasible direction of approach vector is proposed based on the end pose description of degree of freedom constraints. In this method, firstly, the motion space of the end executor is reduced from three dimensions to two dimensions through joint angle parameterization. Then, the feasible direction of the approach vector of the end executor at different target positions (distal, middle and proximal) is analyzed by geometric method, so as to avoid blind parameter setting and ensure the existence of inverse kinematics solutions. Thereafter, the optimal solution is selected according to the motion continuity and motion range of each joint. The simulation analysis results of path planning show that the actual path is very consistent with the planned path and the joint motion is stable, which proves the feasibility and accuracy of the proposed solution method. The 5-DOF manipulator studied in this paper is representative to some extent and the proposed solution method possesses the advantage of low computational complexity and simple solving process. Therefore, the solution idea can provide reference for the inverse kinematics solution of the manipulator with less degrees of freedom.

Dynamic Wear Characteristics of Tooth Profile of RV Reducer for Industrial Robot



ZHOU Jianxing, ZHANG Ronghua, ZENG Qunfeng, et al

2023, 51(1):  22-30.  doi:10.12141/j.issn.1000-565X.220047

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In order to overcome the difficulty in accurate prediction of the dynamic wear of tooth profile of precision RV reducer for industrial robot, this paper took BX-40E reducer as an example, obtained the wear coefficients under different position conditions through equivalent experiment based on the generalized Archard wear formula, with the consideration of the influence of different position conditions after the wear evolution in the wear prediction process. According to the deformation coordination theory and Langkali-Nikraves contact force model, the load distribution and contact pressure between teeth were determined. Considering the time-varying tooth profile wear and meshing force excitation, the numerical calculation model of dynamic tooth profile wear of transmission system was established by analytical modeling method. As compared with the tooth profile wear curve with the constant wear coefficient, both the wear value and the tooth surface distribution are significantly different, and the overall difference increases with the increase of wear times. The accuracy and necessity of quantifying the tooth surface wear with the wear coefficient taking into account the difference of contact position conditions were obtained. The wear depth curve of cycloid gear and needle teeth presents an asymmetric and irregular inverted “W” shape along the tooth profile. Due to the wear, the teeth near the tooth root and tooth top first fall off and then mesh, resulting in impact and micro protrusion peak. There is almost no wear at the concave convex transition position of cycloid tooth profile. With the increase of wear times, the wear peak area becomes narrower, and the non-uniform increase of wear rate slows down. There is a functional mapping relationship between the meshing force and the pressure angle. The results of the study provide a theoretical basis for improving the wear reduction and vibration reduction of cycloidal needle gear.

Pressure-Velocity Compound Control Strategy of Hydraulic System



XIA Yimin, LUO Lianglin, GUO Kun, et al

2023, 51(1):  31-40.  doi:10.12141/j.issn.1000-565X.210814

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Taking the valve control cylinder system controlled by proportional relief valve and proportional speed-regulating valve as the research object, this paper established a dynamics model of hydraulic system. The friction force of propulsion hydraulic cylinder was compensated based on LuGre model. The bristly observer was established to estimate the motion characteristics of the spool and the stability of the observer was proved by Lyapunov first method. The uncertainty of hydraulic system was integrated with external load interference, and the adaptive rate was estimated. Based on the inverse integral adaptive control algorithm, a pressure-velocity compound control strategy was proposed and the stability of the control strategy was verified. Based on the hydraulic cylinder speed control, the pressure error was introduced into the speed expectation to realize the pressure-flow compound control of valve control cylinder system. The co-simulation platform of the valve-controlled cylinder system was established in AMESim and Matlab, and the speed regulation, sudden load and load disturbance of the valve-controlled cylinder system were simulated and analyzed under different error proportions. The simulation results show that the pressure-velocity composite controller has good control performance under the conditions of speed regulation, sudden load and load disturbance of the valve control cylinder system. The overflow control of proportional relief valve effectively reduces the fluctuation and overshoot of system pressure. Overchanging the proportion of pressure error can effectively change the distribution of pressure and velocity error when the formation changes abruptly. In practical engineering, the distribution of compound control error can be carried out by changing the proportion of pressure error according to the need.

Dynamic Characteristics Analysis of Vibrating Screen Based on System and Particle Coupling Dynamics



HE Zhaoxia, WANG Xingzhe, XING Zengfei, et al

2023, 51(1):  41-50.  doi:10.12141/j.issn.1000-565X.220104

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In order to analyze the interaction between the vibration of vibrating screen and the movement of particles and reveal the influence of vibration parameters on the dynamic characteristics of the system, this paper establishes a model for the coupling of vibration sieve system dynamics and particle dynamics. By using this model, real-time bi-directional coupling simulation of screening process can be realized, and the accuracy of the simulation model is effectively improved. The steady-state particle distribution at each layer of screen is obtained based on the actual screening yield which is calculated in terms of screen test. As compared with the uncoupled model, the model considering the coupling of vibrating screen and particle dynamics can obtain more accurate force analysis, and enhance the material throwing of the sieve body, avoiding the particle accumulation of each layer in the traditional simulation, which is more consistent with the actual screening situation. Meanwhile, the coupling analysis also indicates that the maximum impact force of materials does not decrease as the number of screen layers decreases. Finally, the variation law of material impact force with the main parameters of vibrating screen is studied. The results indicate that the impact force of the particles not only varies as the proportion of screen surface area, but also relies on the residence time of the particles on the screen; the impact force of the particles decreases with the increase of the inclination angle of screen surface. When the vibration direction angle is within 57°to 90°, the magnitude of the impact force shows an inverted V-shape. The results provide a theoretical guidance for the dynamic optimization design and noise reduction of vibration screen.

Materials Science & Technology

Study on CMC/CS/Ca²⁺ Composite Hydrogel for Transdermal Delivery of SPE in vitro and Its Antioxidant Activity



YE Jun, LIU Luying, HUANG Zhuosheng, et al

2023, 51(1):  51-60.  doi:10.12141/j.issn.1000-565X.220388

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Peptides, such as soybean peptide (SPE), play an important part in drugs targeted therapy and diagnosis. However, their intolerance for the extremely low pH and ionic barriers of the stomach makes them hard to be delivered orally. Transdermal delivery system can deliver drugs to the blood avoiding the obstacles of the gastric. In this paper, carboxymethyl cellulose/cationic starch/Ca²⁺ (CMC/CS/Ca²⁺) composite hydrogel was successfully prepared by freeze-thaw cycle, and it can overcome the barrier of penetration of water-soluble SPE in the stratum corneum during transdermal delivery. The results of particle charge detector (PCD), Fourier transform infrared spectroscopy (FT-IR) and rheology show that chemical and physical cross-linking occurs among CMC, CS and Ca²⁺, forming a stable hydrogel. Moreover, the interaction among SPE, CS and Ca²⁺ makes its mechanical properties meet the requirements of transdermal delivery. The results of scanning electron microscope (SEM) and specific surface area measurement (BET) illustrate that there is a porous 3D network structure in those composite hydrogels. The moisture content of the composite hydrogel is higher than 95.63% and remains above 97.34% after 25 min at 25 ℃. All composite hydrogels swell rapidly within 120 min, and the equilibrium swelling fraction can reach up to 636.23% at 720 min. Moreover, it is also indicated that the composite hydrogels have high affinity for water, which is the fundamental reason for improving the transdermal delivery efficiency of SPE. The results of in vitro release show that the release type of SPE releasing from hydrogel belongs to swelling controlled release type, and the maximum scavenging rates of DPPH radical and ABTS radical are 47.07% and 72.16%, respectively. The cumulative permeation per unit area of SPE is 0.55, 0.70 and 0.60 mg/cm², separately, and the cumulative penetration percentage is 84.13%, 92.93% and 92.57%, respectively. The appearance and pH value, thermostability and cold endurance of the hydrogel all meet the standards of QB/T 2872—2017. Therefore, these composite hydrogels are expected to be applied not only in transdermal delivery of peptides and protein drugs, but also in skin antioxidant care.

Experiment and Simulation of In-Plane Crushing Performance of Circular Double-Arrow Honeycomb



QI Chang, DING Chen, LIU Haitao, et al

2023, 51(1):  61-68.  doi:10.12141/j.issn.1000-565X.220099

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As a kind of bionic material, honeycomb structure has remarkable advantages in many fields, such as impact energy absorption, lightweight and so on. Among them, the plateau stress and energy absorption of double-arrow honeycomb (DAH) are higher than that of hexagonal honeycomb under compression load. In order to further improve the specific energy absorption (SEA) of DAH, this paper proposed a circular double-arrow honeycomb (CDAH) by introducing double arc edges to replace the original straight edges of DAH, and the CDAH samples were prepared by 3D printing and quasi-static compression tests were carried. At the same time, the numerical simulation model of CDAH was established based on finite element software, and the accuracy of the model was verified by comparing with the experimental results. The critical impact velocity of CDAH was derived by using the impact wave theory, and the dynamic response of CDAH under different impact velocities in the plane was studied with the verified numerical model. The experimental and simulation results show that, as compared with DAH, both the plateau stress and the energy absorption of CDAH are higher. When the strain reaches 0.6, the SEA of CDAH is 71% higher than that of DAH. And there are obvious inverted “V” and inverted “U” shaped deformation bands under medium and high speed impact, showing good characteristics of negative Poisson's ratio. With the increase of impact speed, the plateau stress and specific energy absorption of CDAH are significantly increased, and the plateau stress under 100 m/s impact is 3 times higher than that under 5 m/s impact, which is helpful to the application in high speed impact protection.

Preparation and Properties of Fibrin Gel Tubular Scaffold



LIN Zhanyi, LIU Peng, MEI Jingyi, et al

2023, 51(1):  69-75.  doi:10.12141/j.issn.1000-565X.220062

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Suitable scaffold material is one of the keys to the successful construction of small caliber tissue engineering blood vessels in vitro. Fibrin gel with natural protein composition is an ideal source of scaffold materials. In this study, fibrinogen was used as raw material and mixed with a certain proportion of thrombin and calcium chloride, and the gel material was obtained through technical steps such as temperature control. Then, the clotting time, water absorption, degradation time and mechanical properties were tested. The microstructure of the material was observed by scanning electron microscope. Secondly, the hydrogel tubular scaffold was made by using a specific tubular mold. By loading human fibroblasts in the scaffold, the effect of fibrin gel scaffold on the growth of human fibroblasts was studied and its cytocompatibility was judged. The results show that the overall appearance of the fibrin gel obtained by this method is milky white, smooth and uniform in thickness; the average gel forming time is (172.0±4.7) s; the water absorption rate is 34.50%±1.87%; the complete degradation time is 7 days and the Young's modulus is (2624±295) Pa; the overall structure of the gel has certain stability; the microstructure of the gel is presented as porous mesh fibers, and the fiber diameter is (0.41±0.03) μm with average pore size of reticular fiber of (47.87±9.60) μm². After embedding human fibroblasts, the cells are morphologically intact and evenly distributed in the gel, and the cells survived well. This study provides a reference for the further study of in vitro construction of small caliber tissue engineering vascular graft.

Structure of C-S-H/PCE Prepared from PCE with Different Side Chain Densities and Its Effects on Early Hydration Properties of Cement



YIN Suhong, YANG Xinglin, FENG Xian, et al

2023, 51(1):  76-83.  doi:10.12141/j.issn.1000-565X.220176

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The development of prefabricated buildings increases the demand for using early strong agents in the production of prefabrication. As a new type of crystal early strength agent, synthetic calcium silicate hydrate (C-S-H) can significantly enhance the early strength of cement-based materials, but its poor dispersibility limits its application. In this paper, the polycarboxylate superplasticizers (PCE) with different side chain density were used as a dispersant to synthesis a series of C-S-H/PCE by means of co-precipitation method. The influence of C-S-H/PCE on the structure of C-S-H was studied with XRD, FT-IR, DLC. Moreover, its influence on the cement hydration behavior, hardened body strength and composition structure was investigated. The results show that the smaller the side chain density of PCE, the better the dispersion of C-S-H seeds and the smaller the particle size; the median particle size can reach 339.5 nm; the increase of the number of seed particles can provide more nucleation sites. The incorporation of C-S-H/PCE can significantly accelerate cement hydration, advance the exothermic peak of hydration acceleration by 1.3 h, and increase the heat release by 10.8% at 8 h. After the incorporation of C-S-H/PCE, the porosity of the hardenite of the cement slurry decreases at 8 h and 1 d and the compressive strength increases by 13% and 15%, respectively.

Traffic & Transportation Engineering

Online Joint Estimation of Main States of Lithium-Ion Battery Based on DAEKF Algorithm



LUO Yutao, WU Zhiqiang

2023, 51(1):  84-94.  doi:10.12141/j.issn.1000-565X.220050

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In order to realize the online joint estimation of three major states of ternary lithium-ion battery, namely SOC (State of charge), SOH (State of Health) and SOE (State of Energy), and to deal with the open-loop cumulative error caused by various noises in the actual use of electric vehicles, and, furthermore, to improve the stability of online estimation of lithium-ion battery, this paper proposed an online joint estimation method of the three major states of ternary lithium-ion battery in multiple time scales based on double adaptive extended Kalman filter (DAEKF). In the investigation, the state space equation of DAEKF algorithm is derived based on the second-order RC model, and the parameters are identified online by the recursive least square method with forgetting factor (FFRLS). The SOC and SOE of lithium-ion battery are estimated online in the micro time scale, and the SOH of lithium-ion battery is estimated online in the macro time scale. Thus, the online joint estimation of the three major states of lithium-ion battery can be realized. Finally, the proposed method was verified by experiments under different operating conditions of NVR18650B ternary lithium-ion battery. The experimental results show that the proposed method can rapidly converge the model parameters under the two verification conditions; that the estimation errors of SOC and SOE in the micro time scale are kept within 1%, and the estimation errors of SOH in the macro time scale are kept within 1.6%; and that, as compared with the EKF algorithm, the proposed method has a higher estimation accuracy and better estimation convergence and stability.

Coordinated Optimization Model of Arterial Segmented Green Waves Considering the Efficiency of Tram Operation



WANG Hao, XIE Ning

2023, 51(1):  95-105.  doi:10.12141/j.issn.1000-565X.220111

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In order to improve the traffic efficiency and reduce the stops of tram in intersections, this paper proposes a coordinated signal control optimized method to realize the multimodal segmented green wave control of tram and general traffic. First of all, the signal cycle of each intersection along the arterial is determined. Based on the cycle length, the intersections are clustered and coordinated with the tram departure interval, and the influence of the station location on the tram green wave coordination is discussed. Secondly, constraints are established for general traffic green wave system and tram green wave system to avoid the tram stopping at the intersection. A mixed integer linear planning model is established based on the goal of optimizing the maximum variable green wave bandwidth of general traffic, so as to coordinate and optimize the multi-mode trunk green wave system of trams and general traffic. Finally, a comparative analysis is carried out by using the Nanjing Qilin tram line as a case study. The results indicate that this model can optimize the signal control scheme of arterial segmented green wave which guarantees the passive priority of tram in intersections and running efficiency of general traffic. VISSIM simulation results indicate that, as compared the current signal control scheme, the proposed model can reduce the vehicle delay of each intersection by 20.89%~35.24%; and that, as compared with the MULTIBAND model, this model reduced the delay of person by 6.94%, which improves the overall operation efficiency of the intersection.

Fundamental Diagram Model of Mixed Traffic Flow of Connected Vehicles Considering Time Delay



LUO Ruifa, HAO Huijun, XU Taorang, et al

2023, 51(1):  106-113.  doi:10.12141/j.issn.1000-565X.210702

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Due to the continuous development of connected and automated vehicles, there will be a mixed traffic flow in which intelligent networked vehicles and manual driving vehicles coexist in the future. Therefore, the study of mixed traffic on the road can effectively solve traffic congestion and other problems, so it has certain practical significance. In order to explore the relationship between the flow, density and speed of this type of mixed traffic flow, this paper established a fundamental diagram model of the mixed traffic flow in an autonomous driving environment based on the comprehensive consideration of the degradation of intelligent networked vehicles and the delay between vehicles. First, it determined the types of vehicles in the traffic flow and the proportion of different types of vehicle, and considered the vehicle functional degradation when connected intelligent vehicles follow artificial vehicles. Then, the delay time of each type of three vehicles was determined and the following model of each vehicle was improved. On this basis, considering both the vehicle delay and the vehicle function degradation, the fundamental diagram model of traffic flow balance was derived, and the sensitivity analysis of free flow speed parameter in the model was carried out. The research result shows that connected and automated vehicles have a positive impact on the maximum flow and optimal density of mixed traffic flows, while vehicle delays have a negative impact; the free flow speed has a positive impact on the maximum flow and a negative impact on the optimal density of mixed traffic flow. The SUMO simulation results show that the simulated flow-density distribution points in different scenarios conform to the theoretical curve, which verifies the accuracy of the theoretical model in the paper.

Analysis of Freeway Crash Severity Based on Spatial Generalized Ordered Probit Model



HU Yucong, WEI Hu, ZENG Qiang

2023, 51(1):  114-122.  doi:10.12141/j.issn.1000-565X.210758

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To provide a deep insight into the significant factors that affect the severity of freeway crashes, this study took the crash data from the Dongguan section of the Guang-Shen Yanjiang Freeway in China from 2014 to 2019 as the research object. Crash severity levels were divided into three categories (i.e., no injury crash, minor injury crash, severe injury or fatality crash). Accounting for spatial correlation among adjacent crashes via conditional autoregressive priors, spatial generalized ordered Probit models with different correlation distance thresholds were developed, where the crash severity was used as the dependent variable and 13 potential influencing factors were used as independent variables. The research results show that there is significant spatial correlation among crashes; the spatial generalized ordered Probit models outperform the generalized ordered Probit model and multinomial Logit model; and the spatial model with 250-meters correlation distance threshold achieves the best performance. The results of model parameter estimation reveal that the type and registered province of vehicles, the time of crash occurrence, curvature of crash location, bridge section, and crash type have significant effects on freeway crash severity. The marginal effects of these factors indicate that: as compared with crashes with cars involved only, the involvement of bus, truck and other type vehicles will increase the probability of severe injury or fatality by 3.27%, 1.53%, and 4.11%, respectively; the involvement of vehicles from other provinces will increase the probability of severe injury or fatality by 1.02%; as compared with those occurring on weekend, spring, and bridge, crashes occurring on weekdays, summer, and non-bridge sections would increase the probability of severe injury or fatality by 0.87%, 2.38%, and 0.08%, respectively; the probability of heavy casualties caused by bicycle accidents is 1.64% lower than that of multi-vehicle accidents; the probability of severe injury or fatality will decrease by 1.54% for per 1 km^-1 increase in horizontal curvature of crash location.

Analysis on Propagation of Spatio-Temporal Dynamic Effects Towards Freeway Traffic Crash



YANG Yang, HU Yanran, YUAN Zhenzhou, et al

2023, 51(1):  123-133.  doi:10.12141/j.issn.1000-565X.220353

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This paper aims to explore and quantify the spatio-temporal propagation mechanism of freeway traffic crashes and address the defect of traditional traffic wave theory considering single dimension in such problems. Firstly, the speed changing before and after the traffic crash was analyzed based on the dynamic traffic flow data collected by microwave radar detectors. Furthermore, the speed changing rate was introduced as a measure of the impact of a crash, the bilinear interpolation method was adopted to construct the speed changing rate curve, and the Savitzky-Golay filtering fitting method was applied to fit the outer contour of the spatio-temporal region affected by the crash. Finally, the indicators of spatio-temporal impacts of traffic crash were figured out and analyzed under the condition that the speed changing rate threshold is 20%, 30% and 40%, respectively. The indicators include the beginning time of the crash effect, the end time of the crash effect, the duration of the crash effect, the closest distance of the crash effect, the furthest distance of the crash effect, the spatial range of the crash effect, the propagation speed of the crash effect and the dissipation speed of crash effect. The results indicate that the smaller the threshold of speed changing rate is, the earlier the crash influence starts, the later the crash influence ends, the longer the duration and the longer the distance of the crash influence has; the higher the speed changing rate threshold is, the later the crash influence starts, the earlier the crash influence ends, the shorter the duration and the shorter the distance of the crash influence have; additionally, under various speed changing rate threshold, the changing trend of propagation speed generated by the traffic crash varies with time. The approach adopted in this paper has strong operability and high identification of results, which can provide theoretical support for real-time traffic control and guidance after freeway crashes.

Rutting Abnormality Analysis Method for 3D Asphalt Pavement Surfaces Based on Semantic Segmentation Model



WANG Aidi, LANG Hong, DING Shuo, et al

2023, 51(1):  134-144.  doi:10.12141/j.issn.1000-565X.210778

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Rutting depth is an important indicator for the evaluation of pavement conditions and road maintenance. The existing rutting depth measurement method fails to consider the influence of potholes, raveling, cracks and bridge joints under complex road conditions, and its effectiveness and applicability are limited, and the authenticity of the measurement results remains to be further verified. In view of this, an abnormality detection and correction method based on semantic segmentation model is proposed. The road cross section elevation data is collected by three-dimensional line laser technology, and the rutting depth is extracted by the envelope algorithm. For cross-section of the maximum rut to more than 10 mm, this paper builds a semantic semantic division framework based on deep learning, proposes an improved DeepLabV3+ network to automatically identify and pixel positioning of the disease type, and designs a correction rule based on Lagrangian interpolation to correct the abnormal rut by combining the maximum rut depth elevation points. The results show that the improved DeepLabV3+ model can more accurately identify and locate pavement distress causing rutting abnormality, and its comprehensive detection accuracy of five pavement characteristics and distress reaches 81.63%. Its performance in Mean Intersection over Union (MIoU) and Intersection over Union (IoU) is better than that of U-Net, PSPNet, and DeepLabV3+ models. The field validation results show that the method in the paper can not only automatically analyze the causes of rutting abnormality, but also exclude the influence of other distress by correcting the abnormal rutting, so as to restore the actual rutting depth level to a greater extent. The research results in this paper can provide scientific data support for pavement preventive maintenance.