Research on road and railway vehicle systems

建议的研究重点是通过对公路和铁路车辆系统的分析和实验研究的基础和应用。一些正在进行的，最近发起的和提议的具有实际应用潜力的主题包括：使用先进的被动和半主动概念（包括MR和ER阻尼器）的悬架系统和隔离器，以提高行驶，操纵和动态车轮载荷方面的性能，以及行驶和操纵之间的冲突。在特定应用中，需要为这种阻尼器建立适当的控制器;操纵：转向系统设计中的当前实践使用内外轮角度的固定比率，并且基于低速操纵。申请人提出研究开发速度依赖的自适应转向系统，该系统将显著提高操纵性能，并将显著提高充气轮胎的降噪和寿命;稳定性：通过广泛的模拟研究建立了不随车辆或操作参数变化的侧倾不稳定性的标准化测量。拟议的研究将调查这些措施的应用潜力，并为长货运车辆的早期预警和稳定性增强装置开发开环和闭环控制策略，在长货运车辆中，在后端开始的不稳定性通常直到太晚才被检测到;传感器：申请人建议继续致力于MEMS的动态研究，以开发用于公路和铁路车辆系统的传感器;轮轨接触和轮轨缺陷以及扁疤和擦伤引起的动态力一直是铁路行业维护和安全方面的主要问题。该研究提出了能够预测轮轨动力学的轮轨接触模型的基本重新检查。本研究将发展一个以径向弹簧为基础的车轮模型，并以改良的轨道模型与Hertizan模型及实验数据进行比较。所建立的车辆-轨道模型可用于对给定缺陷的响应识别和智能轮对的开发，以提高铁路轮对的早期检测和及时维护。

The proposed research focuses on fundamental and application through analytical and experimental research on road and railway vehicle systems. Some of the ongoing, recently initiated and proposed topics with potentials for practical application include:  Suspension systems and isolators using advance passive and semi-active concepts (including MR and ER dampers) to enhance the performance in terms of ride, handling and dynamic wheel loads, and conflict between ride and handling. Appropriate controller needs to be established for such dampers in specific applications;  Handling: The current practice in the design of steering system uses a fixed ratio for the angles of inner and outer wheels and is based on low speed maneuvers. The applicant proposes research to develop speed dependent adaptive steering system that will significantly improve the handling performance as well as will significantly enhance the noise reduction and life of pneumatic tires; Stability: A normalized measure of roll instability which is not a function of vehicle or operational parameter are being established through extensive simulation studies. The proposed research will investigate application potentials of the measures and develop open and closed loop control strategies for early warning and stability enhancement devices for long freight vehicles where the instability initiated at the rear end often remains undetected until too late; Sensors: Applicant proposes to continue his effort in dynamic studies of  MEMS towards development of sensors for road and railway vehicle systems; Wheel-rail contact and dynamic forces resulting from wheel-rail defects as well as flats and corrugation have been a major concern for railway industry both for main- tenance and safety. The research proposes fundamental re-examination of wheel-rail contact models capable of predicting Wheel- rail dynamics. The proposed research will develop a radial spring based wheel model with improved rail model to compare with Hertizan model and experimental data. The developed vehicle-track model will be uti- lized towards response identification for a given defect and the development of smart wheelset to enhance early detection and in-time maintenance of railway wheelsets.