汽车稳定性控制轮胎力测试机理与动态解耦优化研究

The present vehicle electronic stability control system (ESC) cannot estimate accurately the wheel forces and their distribution information, especially under the condition of low adhesion road or complex manipulation input, so it is difficult for the ESC to control the unsafe slide out or spin out movement, because the wheel forces acted on the tires play a decisive role on vehicle’s movement. The wheel force transducer (WFT) is an effective means to validate the wheel forces estimation algorithm, but its sensing mechanism applied in the whole vehicle test is still unclear now. In order to improve the wheel force test accuracy, this project will study the wheel force sensing mechanism and dynamic decoupled optimization method based on the WFT with resistance strain principle, in which the effects of the tire rubber is considered extraordinarily. Firstly, the vision sensing technology and the vehicle motion model will be employed to study the tire attitude test methods under the limit conditions, which can obtain the coordinate transformation matrix to improve the wheel force resolution accuracy. Then, the finite element model of WFT with the tire rubber will be built as the simulation platform. The simulation and calibration tests will be conducted to study the WFT calibration and non-linear decoupling methods. Subsequently, this project will explore the WFT comprehensive performance evaluation and its decoupling optimization method based on the indexes such as the structure factor, the comprehensive sensitivity, et al. Finally, the WFT prototype will be improved and used to conduct the comparison tests, which aim to build the wheel force distribution test & control model for driving vehicle. This project will provide the theory and method reference for the independent development of WFT and the accurately quantification of the wheel forces distribution and its variation characteristic for the vehicle stability control.

汽车稳定性控制系统对低附和复杂操控下的侧滑或激转等危险工况难以控制,其实质是对该工况下的轮胎力分布估计不准确,而地面对轮胎的作用力对汽车运动起决定性作用。轮胎力传感器（WFT）是进行轮胎力估算检验的直接有效手段,但在整车应用条件下其测试机理尚不清晰。本项目以提高轮胎力测试精度为主要目标，研究包括轮胎橡胶胎体在内的电阻应变式轮胎力测试机理和动态解耦优化方法。首先基于视觉和车身运动学模型研究极限工况下轮胎姿态测试方法，获取坐标转换矩阵以提高轮胎力解析精度。其次建立包括橡胶胎体在内的整个测力车轮有限元模型，通过仿真和实车测试研究WFT动态标定和非线性解耦方法。然后引入结构因子和综合灵敏度等指标研究WFT性能综合评估和解耦优化方法。最后改进样机进行实车对比试验，建立汽车运动控制过程中轮胎力分布测控模型。本研究将为自主开发WFT以及精确量化汽车运动控制过程中轮胎力分布及其变化特征提供理论和方法参考。

汽车运动主要是由地面对车轮作用力的结果，尤其在极限工况下。车轮力信息是汽车运动控制系统与道路载荷表征的重要基础。对车轮力获取的最直接有效手段是测力车轮传感器。本报告基于国家自然科学基金资助，主要研究目标是基于视觉信息融合方法对复杂多变轮胎姿态进行测量方法研究，实现汽车运动控制坐标系下轮胎力信息准确转换和提取；建立整个测力车轮有限元模型和样机，从减轻质量、提高传感器灵敏度的基振频率等方面对WFT进行解耦优化分析，探索WFT动态耦合标定与非线性解耦方法，最终为准确提取汽车运动控制过程中轮胎力分布特征并建立其控制模型建立系统的理论和方法。主要结论如下。.（1）提出了一种基于加速度的测力车轮传感器转动角度测试方法。该方法能够能消除车轮转向时车轮转动角度测试不准确的问题，有效提高了测力车轮旋转解耦的准确性。.（2）提出了一种4B弹性体的多维力结构解耦方法，给出了具体的各力/力矩结构应变特征分析，并利用ABAQUS有限元进行了仿真实验，结果表明提出的结构解耦方法是有效可行的。.（3）提出了一种基于ABAQUS软件的测力车轮有限元建模方法，特别是其中的胎体与轮辋、弹性体与轮毂适配器、弹性体与轮辋适配器等的接触问题建模。构建了测力车轮样机的有限元模型，并基于该模型进行了布片测点研究和工况输入仿真分析等。.（4）基于虚拟仪器构建了测力车轮测试系统，硬件选型了某轮胎刚度机和MTS Flat-Trac试验平台，数据采集器选型了美国NI的CRIO控制器，软件基于LabVIEW开发，包括运行在cRIO中的数采软件和运行在上位机中的数据采集与分析软件。.（5）开发了一套智能轮胎开发及测试平台，对基于加速度传感器（IEPE）和基于压电薄膜传感器（PVDF）2种传感原理的智能轮胎感知机理进行了系统设计和研究。平台集成轮胎三分力实时测量单元，可实现智能轮胎台架及道路试验的测试和标定，以及其他轮胎内部信息的同步采集，各通道数据采样频率能够实现独立50 kHz。在MTS Flat-Trac轮胎试验台和道路上开展了智能轮胎的系统测试。.项目研究从传统的弹性体研究拓展到整个测力车轮，研究结果更有实际应用价值。本研究为自主开发测力车轮传感器提供了方法指导，为轮胎力测试和汽车运动控制系统开发提供了数据支撑，具有很好的应用前景。