Research On The Hydraulic Control System Of The Anchorage Strength Test Of Car Seat Belt

Car seat belt plays an important role in automobile passive safety and it is one of the important facilities to ensure the safety of passengers in car. Its performance directly affects the safety of the occupants. For the performance testing of the seat belts, China and other countries all over the world have formulated the corresponding testing standards.This paper sets the car seat belt anchorage strength test as the research background, analyzed the national automobile seat test standards according to the technical requirement of automobile safety seat belt anchorage strength test. To satisfy the need of testing equipment status of car seat belt anchorage and business demand, designed the testing equipment and the hydraulic loading system of test equipment.Based on the basic principle of hydraulic proportional control, designed the hydraulic system of car seat safety belt anchorage testing equipment. Use the proportional overflow valve to control the system pressure and ensure the hydraulic cylinder can load smoothly and linearly. Designed the hydraulic circuit of the loading system, select and calculation the hydraulic parts to ensure the equipment could meet the standard of the loading process.Analysis the modeling methods of the hydraulic system with system identification and analytic method, establish the AMESim simulation model of the hydraulic proportion loading system. According to the constitute of hydraulic proportional loading system block diagram, analysis the mathematical model of relationship between input and output, ensure the sub model of the AMESim model by the transfer function model. Obtained the component parameters by experiment and then simulate the model. Hydraulic load simulation and experimental results consistent with the measured load curve. Researched on the static and dynamic characteristics according to the step response and Bode diagram of the system, and found the system has the problem of long convergence time and oscillation. Optimized the system with PID controller, for the AMESim simulation model can easily set the PID parameters and simulation, use trial and error method to get the PID parameter. The convergence time and the vibration amplitude of the optimized hydraulic system are improved effectively, and the overall test performance is improved, which provides a theoretical basis for the specific optimization design of the test equipment.