整体式抱罐车转向动力学建模及转向模式分析
Dynamic modeling and steering mode analysis on integral ladle-transport vehicle

针对高温铁水抱罐车车身惯性积大于主轴惯量，转向时更容易发生侧翻问题。为了增强抱罐车的转向安全性能，以四轴整体式高温铁水抱罐车为研究对象，考虑车身惯性矩阵中的大惯性积，结合阿克曼转向原理以及牛顿-欧拉力学定律，建立抱罐车转向动力学模型。该模型包含车身纵向、横向、横摆、侧倾运动4个自由度，重点分析不同转向模式下抱罐车车身的侧倾运动性能；以某230 t四轴高温铁水抱罐车为试验对象，测试其转向过程中的车身侧倾响应。研究结果表明：转向时抱罐车车身的侧倾角响应是一个随时间逐渐衰减的欠阻尼振动过程，理论计算与试验结果相符，验证了该抱罐车转向动力学模型的有效性；较大的惯性积使车身的侧倾振幅增加了约15%，降低了转向安全性；轮胎转角满足阿克曼定理时，抱罐车转向轴位置变化对车身的侧倾振动频率和稳态响应值没有影响，但是会改变车身侧倾振幅；全轮转向模式（转向轴位置不与车轴重叠）可以获取比六轮转向模式（转向轴位置与某一车轴重叠）更小的车身侧倾振幅，因而转向过程更平稳，安全性更高，并且这一规律不受抱罐车车速与转向半径的影响；在不同轮距、轴距等车辆结构参数下，抱罐车全轮转向模式的侧倾性能优于六轮转向模式。
High temperature ladle-transport vehicle has the characteristic that the inertia product of car-body is greater than the principal axis of inertia, which makes the vehicle easy to roll over in steering. In order to enhance the steering safety of ladle-transport, the steering dynamic model was established for an integral type of four-axle high temperature ladle-transport vehicle combining Newton-Euler mechanics theory together with Ackerman principle, where the huge products of inertia of car-body were taken into account. Four freedom degrees of car-body, such as longitudinal motion, lateral motion, yaw vibration, and rolling motion were included in the model, and the focus was given to the rolling motion of car-body under different steering modes. And experiments were conducted for a four-axle ladle-transport vehicle weighted 230 t to test its rolling behaviors during the process of steering. The results show that the rolling behavior of car-body during steering belongs to an under-damping vibration, which gradually decreases over time. The theoretical results agree well with the experiments, verifying the validity of the steering dynamics model of ladle-transport vehicle. The larger inertia product increases the roll amplitude by about 15% and reduces steering safety. When the steering performance of ladle-transport vehicle meets the Ackerman principle, the change of steering-axle’s location makes effect on the amplitude of roll vibration, but has no influence on frequency and steady-state response. Rolling amplitude of car-body resulted from all-wheel steering, where the steering axle does not overlap with the real axle of vehicle, can be smaller than that resulted from six-wheel steering, where the steering axle overlaps with one of the real axles of vehicle. Therefore, the process of steering is steadier and safer. And this law is not affected by the steering radius and speed of the vehicle. For different structure parameters of ladle-transport vehicle, such as wheel base and axle base, better steering performance can still be obtained from all-wheel