Research on the Best Driving Speed of the Deceleration Bump 2020-01-1088
The ride performance and stability of the vehicle will decrease while the vehicle passing a deceleration bump with a relatively high speed. If the speed is too low, the road efficiency and ride comfort will be affected. It is essential to identify a proper speed taking all the factors into consideration. In this paper, the dynamic model of the vehicle passing through the deceleration bump is established. Two kinds of indicators，vibration weighted acceleration RMS and wheel load impact coefficient, are used to comprehensively evaluate the ride comfort and stability. The highway model, vehicle model and two common trapezoidal and circular cross-sections bump models are set up in Carsim. Parameters such as vertical acceleration and tire force at different vehicle speed are obtained. Then use the nonlinear least square method to fit the data, and comprehensively consider the two indicators to get the best speed. Finally, different deceleration bumps are selected for real vehicle test, and the calculation results are optimized. The results show that for the common B-class and C-class vehicles, it is more suitable to drive at medium and low speed under the common deceleration bumps. The optimal speed of the trapezoidal cross-section deceleration bump is 25-30 km/h, and the circular cross-section deceleration bump is 30-40 km/h, driving at the calculated speed can well meet the comfort and the safety of driving. This research can lay a good foundation for the application of road speed reducer, and it is of great significance to reduce road traffic accidents and improve the safety of vehicles.