【作者】 张浩；

【导师】 李显生；

【作者基本信息】 吉林大学 ， 交通环境与安全技术， 2012， 博士

【摘要】 公路建设和公路交通运输的快速发展，对车辆的操纵稳定性和行驶安全性提出了更高的要求。客车作为便捷交通和快速客运的主体，其操纵稳定性的好坏直接关系到人的生命和财产安全。客车，特别是大客车，由于其功用、结构和载荷形式与乘用车有着显著的差异，研究其操纵稳定性有着重要的意义。因此，深入研究客车动力学特征并掌握其动态特性，分析主要结构参数变化对客车状态参数的影响。在转弯行驶工况下，对客车进行有效的操控、改变稳态转向特性、提高弯道行驶能力，已成为客车领域重要的研究课题之一。本文基于车辆系统动力学，运用Matlab/Simulink仿真分析了客车的动态特性和弯道行驶特性。通过构建客车操纵稳定性检测系统和设计整车道路试验试验方案研究客车的操纵稳定性特征，并在试验验证模型有效性的基础上提出了客车侧倾稳定性的根轨迹分析方法。为提高车辆的弯道行驶的稳定性，进行了控制策略研究，并提出了自适应控制方法。具体研究内容如下：1.通过对客车坐标系和轮胎坐标系的描述，明确各参数变量的坐标系和正负关系。建立客车简化坐标系模型和等效力学模型，并对车辆的侧向运动、车辆的横摆运动和侧倾运动进行了力学分析。针对客车的侧倾运动分析得到三自由度线性方程，通过状态方程的形式给出了车辆系统的求解方法。分析车辆的基本特性参数、悬架特性参数和轮胎特性参数等常见的试验测量方法和经验公式从而为客车仿真参数选取和动力学仿真提供基础。利用Matlab进行了客车系统的动态特性仿真分析，主要是在转向盘转角阶跃输入条件下，研究客车轮胎侧偏刚度、转动惯量和质心高度等参数的变化对系统状态变量的影响，研究结果为客车参数选取和设计提供理论基础和参考依据。最后，研究客车以不同车速在不同转向盘转角输入条件下的转弯特性，通过对客车转弯特性的仿真分析为下文引入客车操纵稳定性控制奠定了基础。2.利用VBOX系列设备，搭建了客车操纵稳定性检测系统。该检测系统是由VBOX3、陀螺仪、汽车操纵力角测量仪、数据采集模块和笔记本电脑等组成。通过对陀螺仪坐标系的标定，明确了陀螺仪坐标系和右手坐标系的关系，确定了其数据处理的方法；根据对汽车操纵力角测量仪的标定，确定了VBOX3采集电压信号和转向盘转角的关系；对VBOX3的动态标定消除了GPS天线安装距离和位置的误差。为了检验系统的稳定性和可靠性，设计了静态检测固定角度、动态检测匀速直线运动和稳态圆周运动客车状态变量的方法，通过理论分析和试验结果对比，验证了该检测系统测量结果的精确度和准确度，为客车操纵稳定性检测提供了试验基础。3.在现有国内外车辆操纵稳定试验方法的基础上，结合客车的特点和检测设备的安装检测方法，制定了客车的操纵稳定性道路试验方案。根据制定的稳态圆周试验、双移线试验和蛇形试验等试验方案，利用所构建的客车操纵稳定性检测系统进行实车道路试验的检测。通过分析检测设备安装位置和测量点位置对测量变量的影响，给出了试验数据的分析处理方法，然后通过试验结果分析了客车在稳态圆周运动、双移线运动和蛇形试验条件下的操纵稳定的特点和状态变量的变化规律。通过客车动力学模型Matlab仿真数据与稳态圆周道路试验数据对比，对所建模型的有效性进行了验证。仿真结果和试验结果所表现出来的车辆运动特性基本一致，验证了所建立客车动力学模型的有效性。4.通过对侧倾稳定性基本概念的介绍，从驾驶员-车辆-道路环境的角度出发对车辆的操纵稳定性进行分析。针对驾驶员因素从感知阶段、判断决策阶段和操作阶段三个阶段分析了其对客车侧倾稳定性的影响；针对道路环境因素从道路表面的附着系数和平整程度以及道路的几何线形的角度分析了其对客车侧倾稳定性的影响；针对车辆相关参数从行驶系、转向系和车辆整体参数的角度分析了其对客车侧倾稳定性的影响。在分析车辆操纵稳定性常用的评价方法基础上采用了根轨迹分析方法，通过固定车速下的转弯特性研究，分析不同转向盘转角输入条件下的横摆角速度和侧倾角的根轨迹变化，对客车的侧倾稳定性进行分析评价。仿真分析结果表明，根轨迹分析方法能够较好的分析客车系统的稳定性，从而为客车的侧倾稳定性分析提供了新方法。5.依据车辆直接横摆力偶矩的控制原理，提出了客车直接横摆力偶矩控制的目标和控制策略。针对PID和模糊逻辑控制的基本理论，设计了横摆角速度的PID控制方法、质心侧偏角的模糊逻辑控制方法以及PID和模糊逻辑联合控制的方法，并通过转向盘转角阶跃输入条件下的仿真分析对控制效果进行了对比。仿真结果表明PID控制、模糊逻辑控制和联合控制均能有效地控制车辆状态变量的稳态值，PID和模糊逻辑联合控制能够解决常规PID控制中控制参数整定方法烦杂的困扰，控制效果要优于单独PID和模糊逻辑控制。为提高控制器的自适应功，能提出了自适应模糊逻辑控制的方法。对模糊逻辑控制中量化因子和分析，研究结果表明所建立的自适应控制方法能够有效地提高客车系统的响应品质和行驶安全性，为提高客车弯道行驶能力提供了有效地控制方法。更多还原

【Abstract】 Vehicle security and handling stability demand need to improve with the rapiddevelopment of road construction and transportation. The stability of bus which isused as the main tools of convenient and fast transportation is directly related tohuman life and property safety. Because of bus especially coach is different from busin function, structure, loading forms and so on; the research on bus handling stabilityhas an important significance. Therefore, researching dynamics of bus system deeply,mastering motion characteristics, analyzing effect to the performance with majorparameters changing of vehicle system, effective controlling of bus to improve activesafety driving in turn driving and complex conditions, etc., have become a importanttopic in the handling and stability research fields of bus.Based on vehicle system dynamics, kinematic characteristics and turn drivingcharacteristics of bus has been analyzed by using computer simulation technology. Bybuilding bus handling stability detection system and designing vehicle road testprocedure of bus, handling stability characteristics are analyzed and effectiveness ofbus dynamics model is verified. Bus roll stability is analyzed by using method of rootlocus. In order to improve bus stability in turn driving control, research on vehiclecontrol strategies are analyzed, and adaptive control methods are proposed. Thedetailed contents are as follows:1. Coordinate system of bus and tire are used to identify the relationship of eachvariables and positive and negative. By establishing bus simplify coordinate systemmodel and equivalent mechanical model, inertial forces and external forces areanalyzed through vehicle lateral movement and vehicle’s yaw motion and roll motion.Three degrees of freedom linear motion equation of bus is established and it can besolved by using method of state space equation. Measurement method of vehicle basicparameters, suspension parameters and tire characteristics and some empiricalformula are proposed, which is very useful for bus simulation and its parameter canbe obtained through this method. By using bus simulation parameter, bus kinematiccharacteristics are analyzed. Bus in steering wheel angle step response is analyzedunder the conditions of different tire wheel cornering stiffness, moment of inertia,centroid height. Simulation results provide a theoretical basis and reference for theselection and design of bus. Finally, turn driving characteristics of bus with differentspeeds in different steering wheel angle input are analyzed. The result laid foundationfor introduction of bus handling stability control for the following.2. Bus handling stability detection system was built by VBOX series equipment,and then it was integrated. Bus handling stability detection system was constituted by VBOX3, gyroscope, vehicle handling and power angle measurement, data acquisitionmodule and notebook computers. Through calibration gyro coordinate system, a clearrelationship between gyro coordinate system and right-hand coordinate system and itsdata processing were obtained. By calibration vehicle handling and power anglemeasurement, the relationship between VBOX3collection voltage signal and steeringwheel angle is identified. The error of GPS antenna installation distance and locationis eliminated through VBOX3dynamic calibration. In order to test the stability andreliability of detection system, a fixed angle of the static detection and dynamicdetection of bus uniform linear motion and steady-state circular motion is designed.Detection system measurement precision and accuracy is verified through theoreticalanalysis and experimental results compared, which provides an experimental basis forbus handling stability detection.3. Based on existing domestic and foreign vehicle handling stability testprocedure, road test program was formulated through the combination of buscharacteristics and the use of testing equipment. Bus handling stability detectionsystem was used to detect bus road test characteristics through steady static circulartest procedure, double lane change test procedure and pylon course slalom testprocedure. Influence between testing equipment installation location andmeasurement point position about measured variables are analyzed and analysismethod of experimental data is given. Test results are used to analyze handlingstability characteristics and state parameter variation through steady static circular testprocedure, double lane change test procedure and pylon course slalom test procedure.Bus dynamic model is verified by comparing between MATLAB simulation andsteady static circular test. Vehicle motion characteristics compared betweensimulation and experimental are basically the same, which verify the effectiveness ofbus dynamics model.4. Basic concepts of roll stability was introduced, vehicle roll stability impactfactor of driver was analyzed from three stages of perception, judgment and operationphase, which is from the view of driver-vehicle-road environment. Vehicle rollstability impact factor of driver was analyzed from road surface adhesion coefficientand the formation degree of the angle of the road geometry. Vehicle roll stabilityimpact factor of vehicle-related parameters was analyzed from driving system,steering system and vehicle overall parameters. Based on analysis of vehicle handlingstability evaluation method, root locus analysis is used to analysis bus handlingstability. Turn driving characteristics of bus is analyzed under fixed speed withdifferent steering wheel angle input. Bus yaw rate and roll angle of the root locus areanalyzed, which are used to analysis and evaluation bus handling stability. The resultsshow that root locus analysis method can analyze bus handling stability effectivelyand given a new method for bus analysis.5. Thought analysis of Vehicle Stability Control and Vehicle Stability Failure, bus direct yaw moment control objectives and control methods are proposed based onvehicle direct yaw moment control principle. Based on PID and fuzzy logic controltheory, PID control method was used in yaw rate control, fuzzy logic control methodwas used in slip angle and PID and fuzzy logic joint control was also used in bussystem. Simulation results show that PID control, fuzzy logic control and joint controlcan effectively reduce steady-state value of bus state parameters. PID and fuzzy logicjoint control can solve the troublesome problem of control parameters in theconventional PID control tuning methods, its control effect is better than separatecontrol. In order to enhance adaptive of controller, adaptive fuzzy logic controlmethod was proposed. Quantization factor and scale factor were optimized by usinggenetic algorithm, and then was simulated. The simulation results can effectivelyimprove the quality of vehicle systems response and security and given an effectivecontrol method for bus turn driving.更多还原