实测轮胎荷载作用下层间接触条件对沥青路面力学响应的三维有限元分析

实际道路中层间接触状态非常复杂,层间接触状态对路面的使用性能有直接影响;并且轮胎与路面的接地形状随着轮胎负荷及胎压的不同呈现出明显的非均匀分布,路面结构内的力学响应也随之发生不规则变化。基于此,采用三维有限元方法,分析在实测轮胎荷载作用下,完全连续、基、面层间光滑两种层间接触状态时,柔性基层和半刚性基层路面力学响应的差异。分析结果表明,层间光滑时面层内的最大剪应力以及层底拉应变均明显增大,相应路面车辙和开裂的机率大大增加,因此必须高度重视层间处理工艺。     

Robust state feedback stabilization of articulated steer vehicles

In this work, a full-state feedback controller is designed to prevent the oscillatory instability or snaking behaviour of an articulated steer vehicle. To design the controller, first, a linearized model of the vehicle is developed and analyzed to identify the most important uncertain tire parameters with regard to the snaking mode. By using this linearized model, the equations of motion are represented in the form of a polytopic system, which depends affinely on the most important uncertain tire parameters. Then, by solving some linear matrix inequalities, both the Lyapunov and state feedback matrices for the robust stabilization of the vehicle are found. The performance of the resulting controller is evaluated by conducting several simulations based on the linearized model. To verify the results from the linearized model analysis, some simulations are also done by a virtual prototype of the vehicle in ADAMS. The results based on the linearized model are reasonably consistent with those from the simulations in ADAMS. They show that the controller can effectively stabilize the vehicle during the snaking mode in different driving conditions.     

Analysis of handling performance based on simplified lateral vehicle dynamics

In this article, the analysis methods for vehicle handling performance are studied. Using simple models, dynamic characteristic parameters such as yaw, natural frequency, and the damping coefficient of a vehicle can be theoretically formulated. Here, the vehicle is simplified by a bicycle (single-track) model, and the tire is modeled by an equivalent cornering stiffness and first order lag. From the experimental road data, the tire model parameters (equivalent cornering stiffness and time lag constant) are extracted. These parameters are then inserted into the theoretically formulated equations of dynamic characteristic parameters. For the purpose of validating the efficiency of the suggested methods, experimental road tests (where the cars have different handling performances) are performed. The results show that vehicle handling performance can be sufficiently represented by the suggested dynamic characteristic parameters. So, it is concluded that the proposed method has practical use for the development of new cars or for the comparison of similar cars since the evaluations of the vehicle handling performance can be efficiently determined by the suggested dynamic characteristic parameters.     

车辆侧向响应特性的多参数影响分析

建立了基于非线性轮胎侧偏特性的四轮车辆数值模型,考虑了轮胎垂直载荷的侧向转移,用该模型计算了车辆转向角阶跃输入下的侧向速度和横摆角速度响应,计算结果表明车辆质心纵向位置对车辆侧向响应特性具有较大的影响,而车辆转动惯量和轮间距对车辆侧向响应特性几乎没有影响.车辆响应特性随车辆质心纵向位置约呈指数关系变化,车辆质心越向前移,横摆角速度的响应也越快但超调量也随之增加.     

轮胎压力监测系统的软硬件实现方法

介绍轮胎压力监测系统的一种半双工实现方法。阐述了基于MPXY8020A传感器、NRF403收发芯片的轮胎监测系统设计方案,给出了各模块的硬件结构、工作流程、通讯协议等。该系统可实时监测每个轮胎内部的实际温度和压力,确定故障轮胎并实时报警,有效避免爆胎事故的发生。     

轮胎中央充放气系统及其技术实现

介绍了轮胎中央充放气系统的基本原理、功能和作用。以某三轴车型为例,对其总体结构设计和关键部位设计进行了阐述。通过试验验证,设计的轮胎中央充放气系统完全实现了车辆行驶过程的测压、充气和放气功能,具有较高的实用价值。     

基于TPMS的轮胎自动降压技术的研究

设计了TPMS系统并提出了一种新型的先导式自动降压电磁阀的设计思想。该系统可实现胎压的实时监测并基于TPMS获得的实时数据实现轮胎的自动降压。     

手持式智能轮胎沟槽深度检测系统设计

针对传统轮胎沟槽深度测量工具检测效率极低、数据不准确、测量维度少和延展性差等特点，设计了一种手持式智能轮胎沟槽深度检测系统。该系统由手持式智能检测设备、手机和云平台三部分组成。手持式智能轮胎检测设备负责采集和处理轮胎沟槽深度数据；手机负责传输和显示轮胎沟槽深度数据；云平台负责分析和存储轮胎沟槽深度数据。试验结果表明，该轮胎花纹深度数据处理算法抗干扰能力强，该手持式智能轮胎沟槽深度检测系统测量效率高，可扩展性强且精度高，每条轮胎检测平均用时4 s，检测数据误差保持在3.5%范围内。     

智能轮胎下沉量实时监测系统设计

从利用轮胎下沉量表征轮胎承载状态的角度出发，设计了一款智能轮胎下沉量实时监测系统，利用单片机处理模块实现对气压、温度、激光测距传感器的集成控制，并采用无线传输的方式将各传感器采集获取的数据传送至上位机显示。经测试，系统工作稳定，满足基本使用要求。     

基于边界分析的重载轮胎滚动过程接地角和印记非对称性分析与验证

基于解析弹性基础的柔性胎体模型,并考虑胎体圆环的径向变形与切向变形之间的耦合关系,为重载大扁平比轮胎建立了柔性环二维轮胎低频动力学模型。采用接地边界求解方法探究了轮胎的接地滚动过程中的接地角和接地印记的非对称特性,并进行了轮胎接地刚度和接地印记非线性实验验证。结果表明:采用接地边界求解可准确计算接地角和接地印记;基于胎内应变传感器的接地印记估计方法可间接测量轮胎滚动过程中的接地印记。