载货汽车多侧翻指标关联性分析与实用化表征方法研究

以优化载货汽车实用化侧翻预警指标表征方法为目的,针对3种侧翻指标(侧向加速度、侧倾角、横向载荷转移率)展开理论关联性分析和动力学仿真试验验证。基于简化的车辆侧倾动力学模型,推导3种侧翻指标关联模型,在Matlab/Simulink中建立基于某轻型载货汽车实际参数的非线性多自由度动力学模型,设置车速与转向角独立变化的2组阶跃转向工况,研究车辆侧翻指标定量关联性及实用化表征方法。通过最终稳定点的分布拟合得到侧倾角和横向载荷转移率与侧向加速度之间的线性数值化模型,进而验证了提出利用侧向加速度间接表征侧倾角和横向载荷转移率的实用化侧翻预警指标表征方法。结果表明:随着方向盘转角和车速的提高,侧倾角和横向载荷转移率与侧向加速度在整个仿真过程中能够快速趋于稳态。通过此法计算出的车辆侧倾角和横向载荷转移率,为后续车辆侧翻预警控制系统的设计提供了良好的指标基础。

Study on the correlation and practical characterization method of multi-rollover indices for trucks

In order to optimize practical characterization method of rollover warning indices for truck, the theoretical analysis of correlation and dynamic simulation test validation are carried out for three kinds of rollover indices (lateral acceleration, roll angle, lateral load transfer rate). Based on the simplified roll dynamics model of vehicle, the model about three kinds of rollover index correlation is deduced, and a nonlinear multi-degree-of-freedom dynamic model with the actual parameters of a certain light truck is established in Matlab/Simulink. The two groups of step-steering with setting the vehicle speed and steering angle changing independently, is used to study the quantitative correlation of vehicle rollover indices and practical characterization methods. The linear quantification model between roll angle or lateral load transfer rate and lateral acceleration is obtained by fitting the distribution of the final stability point. It is verified that the practical characterization method of rollover warning indices that uses lateral acceleration to indirectly characterize roll angle and lateral load transfer rate is feasible. The results show that with the increase of the steering wheel angle and the vehicle speed, the roll angle, the lateral load transfer rate and the lateral acceleration can quickly be tend to stable state in the whole simulation process. The vehicle roll angle and lateral load transfer rate calculated by this method provide a good index basis for the design of the following vehicle rollover warning control system.