【作者】 刘涛；

【导师】 郭孔辉；

【作者基本信息】 吉林大学 ， 车辆工程， 2013， 博士

【摘要】 汽车高速行驶爆胎是一种极其危险的情况，由于绝大多数驾驶员不具备爆胎事故处理经验，在爆胎发生及发展的过程中，驾驶员受到外部环境及自身心理恐慌等多种因素影响而容易采取过度操作甚至误操作，导致恶性交通事故的发生。以往的研究人员在爆胎事故预防以及降低爆胎事故损失等方面都做了大量的研究工作，但其中有些研究工作并不具有针对性，有些在短期内尚不具备实际应用条件。鉴于爆胎事故所造成的人员伤亡及财产损失巨大，但目前对于汽车爆胎相关问题的研究还很不深入，因此本文在总结国内外研究成果的基础之上，以提高爆胎汽车主动安全性为目标，以某国产A级轿车为研究对象，围绕着爆胎轮胎力学特性试验及爆胎轮胎建模，爆胎汽车的运动特性，用于爆胎汽车轨迹跟随的驾驶员模型以及爆胎汽车差动制动控制方面开展研究，主要研究工作如下：1、爆胎轮胎模型建立。爆胎后轮胎的力学特性发生显著变化，建立一个合理的、准确的爆胎轮胎模型是进一步研究爆胎汽车运动特性的关键。为此本文首先完成了标准胎压及零胎压的轮胎力学特性试验，分析了爆胎前后轮胎力学特性的变化以及载荷变化对爆胎轮胎力学特性的影响，并以UniTire模型为基础，将模型中爆胎前后变化较为明显的几个关键力学特性参数进行修正，同时考虑轮胎脱圈与轮辋卡地等情况，建立了UniTire爆胎轮胎模型，实现了对爆胎轮胎力学特性的准确描述并拓展了UniTire模型的应用范围。2、爆胎汽车运动特性研究。爆胎后汽车的运动特性发生了显著变化，深入分析爆胎汽车的运动特性是进一步研究爆胎汽车稳定性控制的关键。分析了爆胎后轮胎工作条件的变化，结合爆胎轮胎的力学特性，分析了爆胎对车轮定位参数的影响以及转向轮爆胎对转向系统的影响，并进一步分析了这些变化对爆胎汽车运动特性的影响。利用所建立的爆胎轮胎模型及整车动力学仿真模型，深入分析了汽车在不同情况下发生爆胎后的运动特性，初步完成了爆胎后的实车运动特性试验。3、用于爆胎汽车轨迹跟随的驾驶员模型研究。将驾驶员模型应用到汽车爆胎仿真中，深入分析了驾驶员模型在汽车爆胎仿真中轨迹跟随精度下降的问题，提出爆胎汽车转向响应特性的改变是导致驾驶员模型在汽车爆胎仿真中轨迹跟随精度下降的根本原因。建立了考虑汽车左、右转向特性不对称的驾驶员模型，仿真结果表明爆胎后汽车轨迹跟随精度有所提高。为了进一步解决此问题，将状态参考器加入到驾驶员模型中，当汽车发生爆胎后，用参考车辆模型与实际车辆模型之间的状态偏差对驾驶员模型输出的方向盘转角进行补偿，建立了用于爆胎汽车轨迹跟随的驾驶员模型，提高了驾驶员模型在汽车爆胎仿真中的轨迹跟随精度。4、爆胎汽车差动制动控制研究。汽车高速行驶爆胎具有极大的危险性，而绝大多数驾驶员往往不具备爆胎事故的处理经验，其错误操作直接导致了爆胎事故的严重后果，因此有必要研究针对于爆胎汽车的控制策略，辅助驾驶员控制爆胎汽车的稳定性与运动状态。为此本文从汽车爆胎的实际出发，分析了爆胎对控制模型中参数的影响，对最优横摆力矩进行修正，提出预防爆胎轮胎脱圈的控制措施，得出了爆胎汽车控制中制动车轮的选择原则，建立了轮缸压力与附加横摆力矩之间的关系，初步探讨了爆胎汽车质心侧偏角估计与如何判断爆胎发生的问题。通过汽车在不同情况下发生爆胎后有无爆胎控制的仿真对比，验证了本文所提出的控制策略不但保证了爆胎汽车的稳定性，而且有效降低了爆胎汽车轨迹偏离程度以及驾驶员转向操作的难度。5、驾驶员在环的控制效果验证。爆胎后驾驶员所采取的操作措施在一定程度上直接决定了爆胎汽车的运动状态及稳定性，而在爆胎发生及发展的过程中，驾驶员所采取的操作措施又具有极大的不确定性，很难用一个准确的驾驶员模型去描述，因此本文借助基于dSPACE的汽车实时仿真平台，将UniTire爆胎模型及整车模型连接到dSPACE中，研究了驾驶员操作对爆胎汽车运动状态的影响，并将爆胎汽车控制系统嵌入到汽车爆胎实时仿真平台中，验证了驾驶员在环的爆胎控制效果。论文主要创新点如下：1、完成了标准胎压与零胎压轮胎力学特性试验，以试验结果为依据，考虑载荷对爆胎轮胎力学特性的影响，建立了UniTire爆胎轮胎模型，实现了对爆胎轮胎力学特性的准确描述；2、深入研究了驾驶员模型在汽车爆胎仿真中轨迹跟随精度降低的问题，建立了用于爆胎汽车轨迹跟随的驾驶员模型，提高了驾驶员模型在汽车爆胎仿真中的轨迹跟随精度；3、考虑爆胎汽车实际情况，提出了基于电子稳定性控制原理的爆胎汽车差动制动控制策略，该策略不但保证了爆胎汽车的稳定性，而且有效降低了爆胎汽车的轨迹偏离程度及驾驶员转向操作的难度；4、基于dSPACE的汽车实时仿真平台，将UniTire爆胎模型与车辆模型连接到dSPACE中，研究了驾驶员操作对爆胎汽车运动状态的影响，并将爆胎汽车控制系统嵌入到汽车爆胎实时仿真平台中，验证了驾驶员在环的爆胎控制效果。更多还原

【Abstract】 The tire blowout is an extremely dangerous situation for the vehicle at high speed. Dueto the psychological panic, the drivers tend to take excessive even wrong operations after tireblowout, which ultimately leads to vicious accidents. The previous researches had largelyfocused on accident prevention and loss reduction, while some of the researches were nottargeted, and some lacked the practical application conditions in the short term.Though the consequent casualties and property losses are tremendous, but the relatedissues are not thorough. On the basis of the research work at home and abroad, thedissertation takes a domestic A-Class vehicle as the object to study the active safety afterblowout. Concerning several main aspects, such as the mechanical properties tests of the tireafter blowout, the relevant tire modeling, the movement characteristics of the vehicle, alsothe driver model for trajectory following and the differential brake control after tireexplosion, the dissertation carries out the following research work:1. The establishment of the tire model after blowout. The mechanical properties of thetire change largely after blowout, so a reasonable and accurate tire model is essential forfurther research on the movement characteristics of the vehicle. Given this, the author firstlytests the mechanical characteristics for the tire under standard tire pressure and zero tirepressure and analyzes the corresponding changes of the tire characteristics when the loadchanges. Based on the UniTire model, several key parameters of the mechanicalcharacteristics, which changes greatly after tire blowout, are modified. And the UniTiremodel for the tire explosion is established when the bead unseating and the rim got stuck inthe ground cracks, so as to improve the accuracy and extend the application range ofUniTire.2. The research on the movement characteristics of the vehicle after tire blowout.Similarly, there exist remarkable changes in the movement characteristics of the vehicle aftertire blowout, which is the key factor for the vehicle’s stability control. Besides the variation of the tire’s work conditions, the dissertation analyzes the influence of the flat tire on thewheel alignment parameters. Specially, the influence of the steering front wheel on thesteering system is also considered. Then the movement characteristics of the vehicle affectedby these factors are discussed in this thesis. With the established blowout tire model and thevehicle dynamics simulation model, the author carries out the analysis of the movementcharacteristics of the vehicle when different tires punctured. Moreover, the correspondingvehicle tests are conducted initially.3. The research on the driver model for trajectory following of the vehicle. Applying thedriver model to the vehicle simulation after tire explosion, the author discusses the precisiondecrease in trajectory following faced by the driver model, and points out it is the change insteering response characteristics that leads the driver model unable to control the vehicleback to its original path when tire blowing out. In addition, having built and simulated thedriver model considering the asymmetric left, right steering characteristic, the paper indeedimproves the trajectory following accuracy. After the foregoing analysis, a state referencedevice is added to the driver model. When a deviation exists, compared with the ideal state,it would compensate the steering wheel angle of the driver model. In other words, with theestablishment of the driver model for trajectory following, the corresponding followingprecision is improved in the tire blowout simulation.4. The differential brake control of the vehicle after tire blowout. It is known to all thatthe tire blowout at high speed is extremely dangerous, and the vast majority of drivers do nothave relevant experience of handling this, which would directly lead to a serious trafficaccident. So it is necessary to do a research on the control strategy so as to assist the driversto control the vehicles’ stability and movements after tire blowout. Considering the actualsituation of the tire blowout, the dissertation analyzes its affect on the parameters of thecontrol model and modifies the optimal yaw moment. Then the control measures to preventtire from bead unseating are put forward. In addition to the selection principle of the brakewheels after tire blowout, the author also establishes the relations between the wheel cylinderbraking pressure and the yaw moment, followed by the estimation of the slip angle for the vehicle and the judgment of tire blowout. Necessarily, considering tire blowout underdifferent conditions, the simulations are carried out with the control strategy mentionedabove, which ensures the stability of the vehicle. Meanwhile, the trajectory deviation of thevehicle is decreased and the steering operation is easier for maneuvering.5. The validation for driver in the loop control. To some extent, what the drivers doafter tire blowout would directly affect the movement state and the stability of the vehicle.While the fact is that the drivers’ operations are of great uncertainty, and the accurate drivermodel is subsequently hard to build. Therefore, the dissertation turns to the dSPACE, a realtime simulation platform. After linking the UniTire model for tire blowout and the vehiclemodel to the dSPACE, the author studies the influences of drivers’ operations on themovement state of the vehicle. With the control system embedded in the simulation platform,the driver in the loop control is validated.Major innovation points of this dissertation are as follows:1、The mechanical characteristics are tested for the tire under standard tire pressure andzero tire pressure. Based on the test results and the load, the UniTire model for tire blowoutis established, and the characteristics could be accurately prescribed.2、The precision decrease in trajectory following faced by the driver model is deeplyanalyzed. In view of this, the driver model for the trajectory following after tire blowout isbuilt, which improves the precision of the model.3、Given the actual situation, the differential brake control strategy after tire blowout,which is based on electronic stability program, is proposed, whose participation in the modelensures the stability. Besides, the trajectory deviation of the vehicle is decreased and thesteering is easier for maneuvering.4、Assisted by the real time simulation platform dSPACE, the UniTire model for tireblowout and the vehicle model are linked to dSPACE. Then the drivers’ operations are takeninto consideration. With the control system embedded in the real time simulation platform,the driver in the loop control for tire blowout is verified effectively.更多还原