Heavy-duty Truck Modeling, Simulation And Analysis Of The Impact Of Assembly On Performance Characteristics

Since 1956, China's first production of a truck up to now, truck has a production history of more than 50 years in China. With the rapid development of economic, national efforts to build infrastructure increases, the deployment of heavy-duty truck's role in the supplies calling has become increasingly. Heavy-duty truck on the national R & D investment intensity is gradually increasing and developing to high-end, large-tonnage. The "Eleventh Five-Year" National High-tech Research and Development Program, the 863 Plan, established two projects about advanced technology of heavy-duty truck.With the development of computer technology, the use of multi-body dynamics software for heavy-duty truck's modeling, simulation and analysis has become an important method of researching heavy-duty truck dynamics. The accuracy of heavy-duty truck models directly affect the reliability of the simulation results, so how to establish an efficient and accurate heavy-duty truck model is worthy of further study.The purpose of this study is based on the requirements of the national 863 project, basing on the raw data given by the enterprise and Trucksim software, explore universal method for determining the parameters of heavy-duty truck and compare the results of simulation with the real vehicle tests to confirm the accuracy of the model. Then study the impact of body, suspension and steering assembly parameters and their interactions on performance, especially the handling and stability performance to find the optimal combination of the assembly parameters. The main contents are as follows:(1) Method of determining heavy-duty truck assembly parameters.In-depth study of Trucksim, according to the relevant principles of theoretical mechanics, automobile construction and automotive theory, researched the method of obtaining assembly characteristic parameters of the heavy-duty truck body, axle and suspension, tires, powertrain, steering and braking systems from the raw data given by the enterprise, including more than 200 groups parameters or characteristic curve parameters, such as vehicle quality and size, tire characteristics, wheel alignment, suspension K & C characteristics, damper, engine, clutch, transmission, differential, brake system and steering system parameters and so on. According to these parameters established vehicle dynamics model by Trucksim and simulation the linear driving conditions, continuous shift driving conditions and steady static circular conditions to debug assembly parameters of heavy-duty truck, solved the problem of describing three-axis heavy-duty truck modeling parameters to model and simulate heavy-duty truck dynamics in Trucksim. (2) Handling and stability, power and braking simulation of heavy-duty truck.For the vehicle shape of simulation animation alike with the real vehicle shape, modify the shape in 3D software Maya for Trucksim animation modules calling. Reference to relevant national standards and real vehicle tests, simulated pylon course slalom test, steering wheel angle step input test, steering angle pulse input test, steady static circular test, returnability test and the steering efforts test, contrasted the results with the real vehicle test results, verify the correctness of the model and then simulated the pylon course slalom test at 70 km/ h for which national standards required but no real vehicle tests there. Reference to national standards, simulated the slipping test, steep hill climbing test, acceleration performance test and maximum speed test. Reference to national standards, simulated the 0-type braking test. The simulations of tests that have not real vehicle test showed the value of the simulation. When some tests have not conducted or have some question, we can analyze its performance through the dynamic simulation.(3) Research on body, suspension and steering assembly parameters' impact on heavy-duty truck performance.Focusing on vehicle handling and stability, made researches on how assembly characteristics affecting vehicle performance. First of all, basing on national standards and relevant literature chose the experimental index for handling and stability test, dynamic test, and braking test. Then changed a characteristic parameter value of the body, suspension and steering assembly and kept the other parameters constant. Simulated vehicle handling and stability to choose parameter which has significant impact on handling and stability test. Designed orthogonal pilot program, and simulated tests follow the program to study the impact of assembly parameters and their interactions on performance of the vehicle to get the impact of test factors and their interactions on the performance, the primary and secondary levels order and the best combination of them. Simulated the performance of the heavy-duty truck with the best combination, and found the vehicle performance improved, applied the direction and basis for the selection of heavy-duty truck assembly parameters and performance optimization.