Modeling And Applications Of Heavy Vehicle Cargo Transport Based On Multibody Dynamics

At present, heavy vehicles large-scale transportation has become one of the main modes of highway cargo transportation in China. With the development of heavy vehicle transport system, heavy vehicle transport, on the one hand, is improving the efficiency of the transport of goods and reducing the transportation cost, but on the other hand the aspacts that mechanical damage of packaging system, driving stability and safety, road alignment design consistency can need to be improved. A closed-loop "intelligent speed control algorithm-truck- good packaging system-road geometric alignment" system (ITGRS) based on dynamic response characteristics of heavy vehicle is established using ADAMS/Truck and MATLAB/Smulink to analysis influence mechanism of vibration and shock response of packaging systems, and that of road alignment design inconsistency. The ITGRS platform proposed in this paper is very important practical significance in goods safe transportation, road alignment design and traffic operation safety.The modelling theory and numerical solution of the multi-rigid-body model and multi-flexible-body model are presented and analysed based on multi-body system dynamics theory. The characteristic parameters and the modeling method of the vehicle dynamics modeling, goods model of packaging system and road geometry module are illustrated in detail to provide reliable theory basis for deeply analyzing the dynamic characteristics of integrated ITGRS system.In integrated ITGRS system, intelligent fuzzy control technology is applied to united simulation between MATLAB/Smulink and ADAMS/Truck. Fuzzy control algorithm can precise manipulate speed control module in accordance with the requirements for the driver’s practical manipulation. The algorithm guarantees the effectiveness of control module in integrated ITGRS system, which provide basis for exploring driving dynamics characteristics in the condition of various complex tests.In order to accurately reflect the robustness and effectiveness of the integrated ITGRS system in real environment, according to same boundary conditions of real vehicle test, some relevant vibration and shock tests on roughness pavement and curve road segment have been done to verify integrated ITGRS model, which provides the reliability test platform for packaging systems fragility spectrum analysis, traffic safety and road alignment design consistency in the process of transportation.In order to explore the vibration and shock response characteristics of the packaging system from road geometry features using the test platform, first of all, selecting typical plank road, ramp road, roof road, sine road, and stochastic uneven road with road roughness characteristic parameters for input excitation, the response function of fragility of packaging system are deduced through nonlinear regression method. Secondly, the three-dimensional boundary characteristic spectrums of fragility are plotted, which are on the basis of limit radius for eigenvalue parameter in the Highway Engineering Technical Standards (HETS, 2014). The fragility response functions and three-dimensional boundary characteristic spectrum of fragility obtained from integrated ITGRS system provide important reference basis for goods transportation safety of heavy vehicle.Finally, taking the heavy vehicle traveling speed, curve radius, maximum superelevation rate, maximum grade, road surface friction coefficient as input excitation of the ITGRS system, the dynamic response characteristics——lateral acceleration, yaw acceleration, tyre-road coupling lateral force, vehicle running state and trajectory, can be attained from heavy transportation vehicle in curves. The safety margins of dynamic response characteristics provide an effective method and visualization research mechanism to identify road traffic safety and minimum radius design consistency.