Tyre pressure monitoring using a dynamical model-based estimator

In the last few years, various control systems have been investigated in the automotive field with the aim of increasing the level of safety and stability, avoid roll-over, and customise handling characteristics. One critical issue connected with their integration is the lack of state and parameter information. As an example, vehicle handling depends to a large extent on tyre inflation pressure. When inflation pressure drops, handling and comfort performance generally deteriorate. In addition, it results in an increase in fuel consumption and in a decrease in lifetime. Therefore, it is important to keep tyres within the normal inflation pressure range. This paper introduces a model-based approach to estimate online tyre inflation pressure. First, basic vertical dynamic modelling of the vehicle is discussed. Then, a parameter estimation framework for dynamic analysis is presented. Several important vehicle parameters including tyre inflation pressure can be estimated using the estimated states. This method aims to work during normal driving using information from standard sensors only. On the one hand, the driver is informed about the inflation pressure and he is warned for sudden changes. On the other hand, accurate estimation of the vehicle states is available as possible input to onboard control systems.     

中重型汽车轮胎异常磨损浅析

在我国整个汽车行业普遍存在一个问题困扰着我们,即轮胎磨损问题,尤其是中重型汽车轮胎异常磨损问题。通过多年来的实践和不懈努力,国内已经总结、积累了一定的解决轮胎磨损的经验。但造成轮胎磨损问题的因素错综复杂,实际问题往往是多种因素共同作用的结果,采用以往的经验并不能完全解决问题,当前国内各汽车生产厂家仍在探索行之有效的解决措施。本文结合市场问题信息收集及服务实践,对中重型汽车轮胎异常磨损影响因素进行简单的分析。     

Bifurcation analysis of an automobile model negotiating a curve

The paper deals with the bifurcation analysis of a rather simple model describing an automobile negotiating a curve. The mechanical model has two degrees of freedom and the related equations of motion contain the nonlinear tyre characteristics. Bifurcation analysis is adopted as the proper procedure for analysing steady-state cornering. Two independent parameters referring to running conditions, namely steering angle and speed, are varied. Ten different combinations of front and rear tyre characteristics (featuring understeer or oversteer automobiles) are considered for the bifurcation analysis. Many different dynamical behaviours of the model are obtained by slightly varying the parameters describing the tyre characteristics. Both simple and extremely complex bifurcations may occur. Homoclinic bifurcations, stable and unstable limit cycles (of considerable amplitude) are found, giving a sound and ultimate interpretation to some actual (rare but very dangerous) dynamic behaviours of automobiles, as reported by professional drivers. The presented results are cross-validated by exploiting handling diagram theory. The knowledge of the derived set of bifurcations is dramatically important to fully understand the actual vehicle yaw motions occurring while running on an even surface. Such a knowledge is a pre-requisite for robustly designing the chassis and for enhancing the active safety of vehicles.     

Comparative study of vehicle tyre–road friction coefficient estimation with a novel cost-effective method

This paper qualitatively and quantitatively reviews and compares three typical tyre–road friction coefficient estimation methods, which are the slip slope method, individual tyre force estimation method and extended Kalman filter method, and then presents a new cost-effective tyre–road friction coefficient estimation method. Based on the qualitative analysis and the numerical comparisons, it is found that all of the three typical methods can successfully estimate the tyre force and friction coefficient in most of the test conditions, but the estimation performance is compromised for some of the methods during different simulation scenarios. In addition, all of these three methods need global positioning system (GPS) to measure the absolute velocity of a vehicle. To overcome the above-mentioned problem, a novel cost-effective estimation method is proposed in this paper. This method requires only the inputs of wheel angular velocity, traction/brake torque and longitudinal acceleration, which are all easy to be measured using available sensors installed in passenger vehicles. By using this method, the vehicle absolute velocity and slip ratio can be estimated by an improved nonlinear observer without using GPS, and the friction force and tyre–road friction coefficient can be obtained from the estimated vehicle velocity and slip ratio. Simulations are used to validate the effectiveness of the proposed estimation method.     

Micro-shimmy of towed structures in experimentally uncharted unstable parameter domain

In this paper, the lateral instability of towed structures (trailers, caravans and articulated buses) is investigated with special attention to the small amplitude lateral vibration that leads to a higher energy consumption in certain parameter domains. A low degree-of-freedom mechanical model of a shimmying towed tyre is used that describes the dynamics of the tyre–ground contact patch by the time delayed differential equation. Stability charts are calculated and the theoretically predicted linear unstable islands of small amplitude shimmy motions are validated by laboratory experiments. A tyre is towed by a relatively long caster, and its temperature and the input current of the conveyor belt are measured in order to show the increased value of the rolling resistance.     

轻型轮胎式集装箱门式起重机

介绍一种轻型轮胎式集装箱门式起重机 (简称四卷筒场桥 ) ,该设备采用了轻型化设计技术 ,具有自重轻、轮压低的特点 ,造价比其他轮胎式起重设备大大降低     

军车轮胎评价指标体系探究

简述了国内外军用车辆配套轮胎发展现状,分析了军用车辆对轮胎的特殊技术要求,根据轮胎与整车性能的相关性分析,运用系统分析和逻辑推理的方法,分别从单胎和整车两个角度构建了军车轮胎的评价指标体系,为军车的轮胎选型、设计和试验评价提供了借鉴。     

港口管理港口流动机械设备轮胎运营管理

对港口流动机械轮胎加强管理有助于企业降低成本,提高效益。分析了大连港湾集装箱码头目前流动机械设备轮胎运营管理面临的困难,从6个方面提出了流动机械设备轮胎规范化、专业化管理的措施,取得了很好的效果。     

节能减排新技术在滨海新区道路工程中的应用研究

"十一五"期间,滨海新区开发开放纳入到国家区域发展战略,掀起了基础设施建设的高潮,为了解决"软基、重载、盐渍化"给滨海新区道路建设带来了的巨大挑战,滨海新区积极开发研究低能环保新材料、新技术,在诸如废轮胎胶粉改性沥青应用、废弃淤泥处置改良、盐渍土固化利用、泡沫轻质土处理软土、无机结合料加固工业碱渣、生态性排水系统设置等方面取得了重大研究突破,针对这些研究成果进行介绍,对其相关技术原理、应用途径进行分析,以便达到示范推广的目的。     

集装箱码头堆场设备运行分析

现今集装箱堆场作业设备装卸工艺呈现多样化趋势,主流作业设备以RTG、ERTG、RMG为主。大连港的集装箱码头对以上三种装卸工艺均有应用,对此三种设备的优缺点、能耗数据等方面进行分析、对比,提出合理建议。