浅析军用车辆大修工时费用构成和计核方法

在军用车辆装备主要技术经济定额和指标中，大修费用定额是一项重要指标。它是汽车大修所耗费工时和物料总费用的限额，一般按汽车类别和型式等分别制订。军车大修费用主要由工时费和材料费构成，根据对承担军车修理任务的工厂和众多大修车辆的调研，我们发现大修工时费用在军车大修费用中占相当大的比例。因此，本文着重就军用车辆大修工时费用的构成和计核方法作一探讨。     

轿车轮胎噪声测试与评价方法研究

以某轿车作为测试平台,通过换装不同型号轮胎,在消声室转鼓上进行了滑行工况下的噪声测试.给出了评价轮胎噪声时轮胎附近、车内的测点位置.通过对不同型号轮胎各测点响度对比分析及同型号轮胎不同测点的频谱分析,提出了在整车消声室内测试与评价轮胎噪声的方法,为整车轮胎噪声的评价提供了试验依据.     

基于接地特性对轮胎综合性能影响的研究

接地特性是影响轮胎力学特性的重要因素,文章分析了同型号轮胎在不同胎压下的花纹特征,研究了轮胎综合性能评价的典型指标,包括轮胎附着力、噪声品质等,通过整车试验对轮胎综合性能进行了主客观对比分析。     

轮胎冲击性能的数值分析方法与研究

基于整车冲击性能评价方法和指标,提出轮胎冲击性能的客观评价方法和指标。对不同组轮胎分别进行轮胎凸块冲击试验,选取径向力和纵向力响应试验数据进行数值分析,经滤波和绝对包络计算并加权平均处理后分别计算得出各组轮胎的冲击强度和残余抖动指标量。通过主客观评价指标量对比分析,验证了所提出的轮胎冲击性能客观评价方法和指标及数值分析方法的有效性和准确性。     

基于ECE R117的C1类轮胎雪面抓地性能测试研究

分析了欧盟ECE R117针对C1类轮胎的雪面抓地性能测试方法,建立了C1类轮胎的雪面抓地性能测试评价流程,结合CATARC寒区试验场,进行了C1类雪地轮胎雪面抓地性能评价方案的可行性测试试验,为我国轮胎企业的产品性能开发、测试评价标准制定、轮胎与整车性能匹配及申请欧盟认证提供了技术储备。     

轮胎结构对汽车使用性能影响的试验研究

本文以轿车上常用的子午线轮胎为例,通过理论分析和装车试验,对比、评价子午线轮胎的结构特性对汽车性能的影响,并以汽车的使用性能为侧重点,探讨轮胎与整车匹配的     

某越野车型更换大尺寸轮胎布置选型分析

在汽车总体设计中,轮胎是汽车的重要安全部件,轮胎的选型换型关系到汽车的动力性、经济性、操纵稳定性、通过性、制动性、承载能力等。轮胎的性能不仅取决于轮胎本身,更取决于轮胎与汽车的匹配。目前,整车厂家对轮胎与汽车性能的匹配要求日益提高。通过对匹配轮胎的动态运动校核、整车布置、整车操稳平顺性、动力性和经济性的影响分析,进行某越野车型更换大尺寸轮胎的布置分析。通过整体布置分析、仿真计算和试验验证,完成了轮胎的换型,同时也细化和规范了轮胎布置设计流程,积累了一定的经验。     

轮胎对轻卡直线行驶稳定性的影响分析

直线行驶稳定性是轻卡性能的重要评价指标之一,其不仅影响到驾驶舒适性,在高速工况下甚至影响到整车的安全行驶。直线行驶稳定性受整车的悬架、前后桥、轮胎、车架等影响,文章主要分析轮胎的相关特性对行驶稳定性的影响。     

轮胎模型刚度对前部偏置碰撞结果的影响

建立了整车碰撞模型中的轮胎模型后,通过调整模型参数,使模拟的轮胎刚度特性曲线近似于试验的轮胎刚度特性曲线,并应用于整车前部偏置碰撞模拟中,分析轮胎刚度对偏置碰撞结果的影响.结果表明,轮胎刚度对碰撞过程整车加速度、截面力、防火墙侵入量等均有一定的影响.     

轿车轮胎道路试验客观评价指标及方法概述

本文全面阐述在进行轮胎的对比评价试验和认证试验时,轿车轮胎的声学性能、滚动阻力、动力学极限和耐磨性等评价指标及相应的评价方法,为不同轮胎产品间的对比,以及与轮胎相关的整车舒适性、经济性、动力学性能和可靠性的提高提供参考。     

A vehicle ABS adaptive sliding-mode control algorithm based on the vehicle velocity estimation and tyre/road friction coefficient estimations

A sliding-mode observer is designed to estimate the vehicle velocity with the measured vehicle acceleration, the wheel speeds and the braking torques. Based on the Burckhardt tyre model, the extended Kalman filter is designed to estimate the parameters of the Burckhardt model with the estimated vehicle velocity, the measured wheel speeds and the vehicle acceleration. According to the estimated parameters of the Burckhardt tyre model, the tyre/road friction coefficients and the optimal slip ratios are calculated. A vehicle adaptive sliding-mode control (SMC) algorithm is presented with the estimated vehicle velocity, the tyre/road friction coefficients and the optimal slip ratios. And the adjustment method of the sliding-mode gain factors is discussed. Based on the adaptive SMC algorithm, a vehicle's antilock braking system (ABS) control system model is built with the Simulink Toolbox. Under the single-road condition as well as the different road conditions, the performance of the vehicle ABS system is simulated with the vehicle velocity observer, the tyre/road friction coefficient estimator and the adaptive SMC algorithm. The results indicate that the estimated errors of the vehicle velocity and the tyre/road friction coefficients are acceptable and the vehicle ABS adaptive SMC algorithm is effective. So the proposed adaptive SMC algorithm can be used to control the vehicle ABS without the information of the vehicle velocity and the road conditions.     

Tyre friction behaviour under abrupt wheel torque transients on slippery road surfaces: experimental analysis and modelling

The paper shows that, during abrupt wheel torque transients for ice surface and low vehicle speeds, the tyre can develop significantly larger longitudinal force than the peak value of the tyre static curve. This so-called dynamic tyre friction potential (DTFP) effect has many influencing factors such as the rate of change of the wheel torque, the vehicle speed, and the tyre dwell time. The paper presents a detailed analysis of the DTFP behaviour based on the experimental data collected by using an in-wheel motor-based tyre test vehicle. The analysis results and an insight into the brush structure of a tyre model lead to the hypothesis that the different influencing factors may be predominantly explained by the bristle dwell time (BDT) effect. Following this hypothesis, the LuGre model of the tyre friction dynamics is extended with a physical BDT sub-model. The experimental validation results show that the proposed model can accurately capture the low-speed tyre–ice friction behaviour during abrupt wheel torque transients.     

Tyre–road grip coefficient assessment. Part 1: off-line methodology using multibody dynamic simulation and genetic algorithms

A key factor to understand the vehicle dynamic behaviour is to know as accurately as possible the interaction that occurs between the tyre and the road, since it depends on many factors that influence the dynamic response of the vehicle. This paper aims to develop a methodology in order to characterise the tyre–road behaviour, applying it to obtain the tyre–road grip coefficient. This methodology is based on the use of dynamic simulation of a virtual model, integrated into a genetic algorithm that identifies the tyre–road friction coefficient in order to adjust the response obtained by simulation to real data. The numerical model was developed in collaboration with SEAT Technical Centre and it was implemented in multibody dynamic simulation software Adams®, from MSC®.     

高速公路爆胎事故的影响因素及其预防

通过调查和实验分析,影响爆胎事故的有轮胎气压、车辆装载质量、行车速度和轮胎磨损4个主要因素,高速公路的道路特点和车辆的运行特点(如高速度、重装载、远距离)对这些因素有着直接的影响,控制这些因素所带来的影响,可以有效地预防高速公路爆胎事故的发生。     

Estimation of the tyre–road maximum friction coefficient and slip slope based on a novel tyre model

In this article, a new approach to estimate the vehicle tyre forces, tyre–road maximum friction coefficient, and slip slope is presented. Contrary to the majority of the previous work on this subject, a new tyre model for the estimation of the tyre–road interface characterisation is proposed. First, the tyre model is built and compared with those of Pacejka, Dugoff, and one other tyre model. Then, based on a vehicle model that uses four degrees of freedom, an extended Kalman filter (EKF) method is designed to estimate the vehicle motion and tyre forces. The shortcomings of force estimation are discussed in this article. Based on the proposed tyre model and the improved force measurements, another EKF is implemented to estimate the tyre model parameters, including the maximum friction coefficient, slip slope, etc. The tyre forces are accurately obtained simultaneously. Finally, very promising results have been achieved for pure acceleration/braking for varying road conditions, both in pure steering and combined manoeuvre simulations.     

论轮胎的磨损

轮胎磨损除会直接增加汽车的使用成本外，还会影响汽车的功率消耗、轮胎与路面间的附着性能等。对轮胎磨损的机理进行了探讨，并着重讨论了影响轮胎磨损的各种因素及其影响机理。通过分析得出的一些结论对正确设计和使用汽车轮胎具有一定的指导意义。     

Sliding mode-based lateral vehicle dynamics control using tyre force measurements

In this work, a lateral vehicle dynamics control based on tyre force measurements is proposed. Most of the lateral vehicle dynamics control schemes are based on yaw rate whereas tyre forces are the most important variables in vehicle dynamics as tyres are the only contact points between the vehicle and road. In the proposed method, active front steering is employed to uniformly distribute the required lateral force among the front left and right tyres. The force distribution is quantified through the tyre utilisation coefficients. In order to address the nonlinearities and uncertainties of the vehicle model, a gain scheduling sliding-mode control technique is used. In addition to stabilising the lateral dynamics, the proposed controller is able to maintain maximum lateral acceleration. The proposed method is tested and validated on a multi-body vehicle simulator.     

Identifying tyre models directly from vehicle test data using an extended Kalman filter

Individual tyre models are traditionally derived from component tests, with their parameters matched to force and slip measurements. They are imported into vehicle models which should, but do not always properly provide suspension geometry interaction. Recent advances in Global Positioning System (GPS)/inertia vehicle instrumentation now make full state measurement viable in test vehicles, so tyre slip behaviour is directly measurable. This paper uses an extended Kalman filter for system identification, to derive individual load-dependent tyre models directly from these test vehicle state measurements. The resulting model therefore implicitly compensates for suspension geometry and compliance. The paper looks at two variants of the tyre model, and also considers real-time adaptation of the model to road surface friction variations. Test vehicle results are used exclusively, and the results show successful tyre model identification, improved vehicle model state prediction – particularly in lateral velocity reproduction – and an effective real-time solution for road friction estimation.     

沙漠车在塔克拉玛干沙漠牵引通过性能的试验研究

设计制造了一套沙漠车模引的电测试验装置，对浙江省车在塔克拉玛干沙漠中行驶时的驱动桥扭矩，挂钩力，动裁，车速，车轮轮速等参数进行了现场测量，得出了沙漠车在不同轮胎气压下的牵引系数，牵引效率和动阻力系试验结果对沙性性能的评价和改进具有指导意义。