【作者】 高红博；

【导师】 许洪国；

【作者基本信息】 吉林大学 ， 交通环境与安全技术， 2014， 博士

【摘要】 近年来，伴随着甩挂运输的大范围推广，半挂汽车列车已经成为了公路运输车辆的主体，但由于汽车列车自身结构的复杂性、车辆安全性评价体系不完善以及牵引车和半挂车匹配不合理等因素，导致由半挂汽车列车引发的交通事故一直居高不下。车辆制动稳定性直接影响车辆的行驶安全，作为高效运输工具的半挂汽车列车在制动时，由于特殊的车辆结构和行驶环境，比单体车辆更容易发生失稳，尤其是在弯道制动，极易发生甩尾、折叠甚至侧翻等危险工况，从而引发恶性交通事故。因此，开展半挂汽车列车弯道制动的方向稳定性研究，分析车辆转弯制动的失稳机理，提出改善车辆转弯制动方向稳定性的控制策略，对保障公路货物运输的安全、顺畅有重要的现实意义。本文首先建立了包括制动系、转向系、非线性轮胎、悬架和鞍座组成的半挂汽车列车底盘系统模型，其中利用相关数据完成了轮胎模型的特性仿真。在此基础上根据车辆动力学原理，建立了包含载荷转移在内的半挂汽车列车19自由度动力学模型，并利用Matlab/Simulink完成了仿真模型的构建。其次依据半挂汽车列车行驶特点，搭建了由VBOX Ⅲ、陀螺仪、汽车操纵力角测量仪、制动踏板计和制动触发条组成的半挂汽车列车行驶稳定性检测系统。制定了半挂汽车列车稳态圆周运动和定半径转弯制动的试验方案，通过实车道路试验，验证了所建模型的可靠性。利用所建仿真模型，针对半挂汽车列车结构参数和使用参数对车辆转弯制动方向稳定性的影响进行了仿真分析，并提出了改善意见。同时，理论分析了半挂汽车列车转弯制动引起失稳的机理原因，并仿真验证了理论分析的正确性。最后为提高半挂汽车列车转弯制动方向稳定性设计了控制策略，即在控制轮胎最佳滑移率的基础上，以差动制动作为主要执行方式，侧向加速度、牵引车横摆角速度、铰接角和铰接角速度为控制参数的多目标LQR最优控制。控制仿真结果表明，所提出的主动控制策略可显著提高半挂汽车列车弯道制动的横摆稳定性和侧倾稳定性，为车辆稳定性控制系统的进一步研发提供了技术参考。更多还原

【Abstract】 In recent years,with the widely popularizing of Drop and Pull Transport,Tractor-semitrailer has become the subject vehicle of road transport.But the amount oftraffic accident triggered by Tractor-semitrailer has been high level all the time due tothe complexity of body structure|,the imperfection of safety assessing in combinationof vehicles and unreasonable matching in tractor and trailer.Braking stability of the vehicle has been constant attentioned as a problem tosolve. It is easier to lose stabililty than single vehicle when Tractor-semitrailer brakein a high speed transporting, with the reason of road environment complexity and highspeed, especially brake in the corners, which is more easier to produce major accidentof sliding, jackknifing and rolloverring.Therefore, this article focused on the instability mechanism ofTractor-semitrailer steering and braking based on vehicle dynamics theory, whichanalyzed the influence of related parameters on the direction stability whenvehicle braking in a turn, and proposed a control strategy to improve stability ofvehicle steering and braking.Firstly, it was established a chassis system model included braking system,steering system, nonlinear tire, suspension and saddle, and realized the characteristicssimulation of tire model using related parameters. On this basis, developed a18-DOFTractor-semitrailer nonlinear dynamics model considering load transfer invehicle dynamics to describe the motion characteristics of tractor-semitrailer brakingin a turn, and finished the construction of simulation model using byMatlab/Simulink.Built a driving stability detection system of Tractor-semitrailer composed ofgyroscope,VBOX Ⅲ, steering force and angle measuring instrument, brakepedal and brake trigger.Formulated a scheme of Tractor-semitrailer driving circle instability and braking in a turn, and carried out the road test of real vehicle, analyzedthe driving characteristics simulation of vehicle from the test result and calibrated thereliability of simulation model. Meanwhile, simulated and analyzed the effect ofstructure parameters and operation parameters on the direction of Tractor-semitrailersteering and braking, and some improving advice were given from which. At the sametime, with the help of vehicle dynamics theory, theoretically analyzedthe reasons caused by losing stability of vehicle steering and braking, validated thecorrectness of theory analysis from the simulation result output by simulation model constructed.Finally, designed the control strategy according to the mechanism of vehiclelosing stability to improve the stability of Tractor-semitrailer braking in a turn, whichis multi-objective LQR optimal control strategy in lateral acceleration, yaw rate oftractor,jackknifing angle and jackknifing angle rate, Based on the optima control oftire slip rate and the main execution way of differential braking controlling. It wasshown that from the simulation, this active control strategy proposed canimprove the yaw stability and roll stability when Tractor-semitrailer steering andbraking, which can provide technical reference for further development in stabilitycontrol system.更多还原