| With the sustaining and rapid economic development in China, hazmat carrying trade has been unprecedented flourishing. At the same time, the volume of hazmat transportation has been rising continually. As the need of high-speed development of freeway and modern logistics, and the further integration (heavy-duty, container, Train and so on) and specialization (van-type transportation, professional transportation and special transportation) of highway transportation, heavy truck, especially the semi-trailer develops more rapidly. Hazmat transportation in China develops gradually from the current transportation form of medium and short distance, and medium and small load to the one of long distance and large load (heavy). Allopatry , long-distance, and large-tonnage transportation has become the general status of hazmat transportation in China.Although it greatly improves the transit efficiency, semi-trailer hazmat transportation brings a great deal of hidden risk, for example, serious accidents frequently happen in highway hazard transportation, and oversize accidents are shocking. The safety of semi-trailer for hazmat transportation has become a bottleneck of restricting the development of road transportation.Facing the increasingly severe security situation of road transportation, the United States, Japan and other developed countries have carried out a great deal of work in the warning system of vehicle safety monitoring, such as warning system of dangerous state for vehicle, collaborative system between vehicle and road, risk preventing system before a curve, vehicle rollover warning and controlling system etc. Intelligent transportation system based on the integration of human, vehicle and road is the developing trend of road traffic safety, thereinto the technology of getting the safety state of vehicle and monitoring and early-warning is one of the research emphases. Transfer from macro industry management to micro technology management is the changing trend of hazmat transportation management in developed countries. Research on the monitoring and early warning of state in transit of hazmat transportation is the frontier technology and research focus.In the "National Plan for Medium and Long Term Science and Technology Development (2006-2020)", the development of technology for preventing and early warning and emergency treating of traffic accident was classified as the priority themes in the field of transportation industry. While in the field of public security, improving early detecting and preventing capabilities for the accident was acted as the train of thought, and leakage monitoring of hazmat, early warning and emergency rescuing technologies were acted as the key technologies. Therefore, active technologies of monitoring and early warning for the hazmat transportation have become the major technical requirement of our country.This thesis just combines with the technical requirement in active monitoring of hazmat transportation, at the same time is based on the Technological Developing Project of Jilin Province"Research of Integrated Monitoring and Early Warning Technology for Road Transportation of Hazmat", the 863 Project"Integrated Testing or Early Warning Technology and Device for Operating Motortruck Safety Performance"and National Natural Science Foundation Project"Research on the Key Monitoring and Early Warning Techology for the Safty of Hazmat Transportation Based on GIS-T", chooses semi-trailer vehicle for hazmat transportation as the research object, regards the active early warning of vehicle sideward rolling safety as the target, respectively identifies the roll dangerous state of van semi-trailer hazmat transportation and liquid tank semi-trailer hazmat transpotation while turning, and studies the related laws among the parameters (steering wheel angle, vehicle speed and cargo filling coefficient, and so on). Research in the thesis mainly contains the following aspects:(1) From the perspective of vehicle dynamics modeling method, kinetics equation solving method, the working process of VS solver's, tire model and suspension performance of TruckSim software, the modeling methods of every subsystems for semi-trailer are deeply analyzed, and the required parameters (property curves) of car body, load, tire system, suspension system and other subsystems in the modeling process are studied. Respectively, the actual operation of van semi-trailer, solid-state hazmat transportation and a half tank of liquid hazmat transportation are taken as the research objects, based on the actual parameters, dynamic models of the whole vehicle are built in the Trucksim simulation environment. The the tractor and trailer moving law is analyzed under the condition of fixed speed and sinusoidal input of steering wheel angle and different speed and step input steering wheel angle, the order of main body while the risk of sideward roll happens during vehicle runing process is established.(2) The influencing factors of roll stability when the semi-trailer turning are analyzed, the basic parameters of the running state identification model of hazmat transportation vehicle are determined. When vehicle turning, taking the inside wheel of the semi-trailer just off the ground as the determinant condition for the sideward roll risk. For the condition of non-partial set, the relationship among the density for different values of the goods, the semi-trailer cargo filling factor K, the vehicle speed V and steering wheel angleθ(involving turning radius) are studied when the roll risk of semi-trailer happens. Then the K/V/θroll threshold identification model under different cargo density is gotten by simulation. Aiming at the problem of prone to the partial set when cargo loading process, the relationship among the eccentricity of goods a, the vehicle speed V and steering wheel angleθ(involving turning radius) is studied when the roll risk of semi-trailer happens. Then the a/V/θroll threshold identification model under different cargo loading M and centroid height h values is established by simulation. Finally, according to the curves from the corresponding parameters, the threshold identification model curve of each parameter for non-partial load and partial roll are compared, and their change regularity are analyzed.(3) The motion law of the ideal pendulum, the pendulum with a system acceleration and the pendulum with vibration damping are respectively reasearched. Based on the analysis of the existing washboard layout on a semi-trailer tank with liquid hazmat, the tank liquid swing around the tank is abstracted as a swinging damping pendulum rounding the cross-section center. Then, the relationship of the tank liquid's centroid position and the liquid loading coefficient is gotten by analysising and calculating. Taking the liquid propylene as the tank containing liquid, and the physical function parameters of liquid propylene at room temperature as an index, the law of the shimmy damper attenuation in round cans body is studied. Assuming that the liquid does not shimmy, the acceleration is respectively gotten by simulation when a semi-trailer take a turn and under the conditions of differet loading coefficient K. And thus the transverse eccentricity a as well as the horizontal distance from the vertical uplift c are gotten when the liquid shimmy. Finally, the relationship among loading coefficient K the vehicle speed V and steering wheel angleθ(involving turning radius) is studied by simulation when the roll risk of semi-trailer happens under the conditions of liquid shimmy, and then the K/V/θroll threshold identification model is established.(4) According to similarity theory, a experimental platform of similar model is built. The similar conditions and similar criteria between the model vehicle and the prototype vehicle are studied. Through the research of program design, data parse, data synchronization, a data collecting system is developped. Finally, the experimental results are gotten by similar model experiment, and through the compare with the results between experiment and simulation, the consistency is proved. How to identify the dangerous state of the hazmat transportation vehicles in the change of different behavior parameters is the technical problems in actively monitoring and early warning technology of anti-rollover. The research has important theoretical value and practical significance, and it can provide reference for the early warning of the vehicle dangerous state in cooperative system of vehicle and road.
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