液体粘性联轴器驼峰特性

本文分析了四轮驱动汽车用液体粘性联轴器驼峰现象的产生条件和形成机理，并对各种结构参数对驼峰特性的影响进行了深入系统的试验研究，获得了硅油粘度，硅油填充率以及输入转速等参数对驼峰特性的影响，研究结果对粘性联轴器设计开发具有指导意义。     

粘性联轴器在常时四轮驱动汽车上的应用

常时四轮驱动汽车在实用化过程中遇到问题，介绍了一种新型的结构装置－粘性联轴器的结构原理和特性。     

粘性联轴器转矩特性的试验研究

本文通过台架试验研究了粘性联轴器的转矩特性，根据试验结果分析了硅油的粘度，填充率和片间间距以及转速差对粘性联轴器转矩特性的影响，并对粘性联轴器转矩特性的峰值现象作了分析。     

车用粘性偶合器

如今,四轮驱动已经不再是一个陌生的名词,它早已超越越野车的范畴,在休闲车中大行其道.现代四轮驱动汽车多采用常啮合式四轮驱动方式,可以自动转换驱动形式.这是因为,它有一个起关键作用的部件叫做粘性偶合器,又称为粘性联轴器.     

液体粘性离合器在适时四驱汽车上的应用研究

通过分析液体粘性传动技术的结构及原理,对其在适时四轮驱动汽车上进行应用研究。系统阐述了粘性联轴器由油膜粘性剪切工作状态到混合摩擦状态的变化过程及其转速的无级调节原理,并利Solidworks三维软件对液体粘性离合器(LVC)进行实体建模,进而对其关键部件进行有限元分析及系统的转矩传递特性分析。最终通过讨论其在实际应用中的优缺点,提出合理的(LVC)应用及布局形式,对推广车用粘性传动技术具有现实的指导意义。     

马自达公司家族型常四轮驱动汽车的中心差速器和差速锁

在常四轮驱动系统中,中心差速器对于吸收前后轴转速差是不可缺少的。本来中心差速器与两轮驱动系统的差速器基本相同,但由于马自达(MAZDA)公司在日本首先在“家族”(Familia)型汽车上采用四轮驱动系统,有必要将其结构和性能加以说明。     

四轮驱动汽车的型式及其基本特性

各种各样的四轮驱动汽车可归纳为二大类,即部分时间四轮驱动和全部时间四轮驱动。前者为一般越野汽车结构,可按道路情况操纵分动箱以选择四轮或二轮驱动;后者则始终以四个车轮为驱动轮,通过中央差速器或粘性离合器予以实现。可以预料,全部时问四轮驱动汽车的生产和销售在近期内将迅速增加,原因就是这种汽车的性能和操纵性都较为优越。在结构方面,过去主要指带有中央差速器的四轮驱动汽车,最近又出现一些较新形式,如不带中央差速器的以粘性离合器、多片式液力离合器或超越离合器作为传动的汽车,图1即为其简单分类。     

4＊4越野汽车驱动力分配

越野汽车当采用四轮驱动时，行走机构的动力学特性要比两轮驱动时复杂一些，本文重点分析了没有轴间差速器的４＊４越野汽车行走前后允动间驱动力的分配。     

什么是车用粘性偶合器?

四轮驱动已经不是一个陌生的名词,它早已超越越野车的范围,在休闲车中大行其道。现在的四轮驱动小汽车多采用常啮合式四轮驱动,可以自动转换驱动形式。它有一个起关键作用的部件叫做粘性偶合器,又称为粘性轴器。     

一汽丰田RAV4主动转矩控制四轮驱动系统(下)

(4)四轮驱动的无级控制 四轮驱动控制ECU通过防滑控制ECU的输出,得到4个车轮的转速信号,根据车辆前、后轮的转速差,通过计算来控制流向线性电磁阀工作电 流的大小.     

Distributed and self-adaptive vehicle speed estimation in the composite braking case for four-wheel drive hybrid electric car

Considering the controllability and observability of the braking torques of the hub motor, Integrated Starter Generator (ISG), and hydraulic brake for four-wheel drive (4WD) hybrid electric cars, a distributed and self-adaptive vehicle speed estimation algorithm for different braking situations has been proposed by fully utilising the Electronic Stability Program (ESP) sensor signals and multiple powersource signals. Firstly, the simulation platform of a 4WD hybrid electric car was established, which integrates an electronic-hydraulic composited braking system model and its control strategy, a nonlinear seven degrees-of-freedom vehicle dynamics model, and the Burckhardt tyre model. Secondly, combining the braking torque signals with the ESP signals, self-adaptive unscented Kalman sub-filter and main-filter adaptable to the observation noise were, respectively, designed. Thirdly, the fusion rules for the sub-filters and master filter were proposed herein, and the estimation results were compared with the simulated value of a real vehicle speed. Finally, based on the hardware in-the-loop platform and by picking up the regenerative motor torque signals and wheel cylinder pressure signals, the proposed speed estimation algorithm was tested under the case of moderate braking on the highly adhesive road, and the case of Antilock Braking System (ABS) action on the slippery road, as well as the case of ABS action on the icy road. Test results show that the presented vehicle speed estimation algorithm has not only a high precision but also a strong adaptability in the composite braking case.     

线控转向系统转向盘力回馈控制模型的研究

根据轮胎和传统转向系的力学特性提出了利用车轮转角和车速计算得到转向盘回馈力的思路,并以此建立了线控转向系统转向盘回馈力控制模型,仿真和试验表明该模型能够满足路感要求。     

电传动矿用自卸车轮边电机驱动系统动态特性研究

矿区环境复杂,电传动矿用汽车的轮边电机传动系统对整车动力性、制动性及平顺性有极大影响,为了综合路面激励和电机自身激励综合分析驱动系统动态特性,采用数值仿真软件建立轮边电机传动系统模型,分析其在启动加速、平稳运行及制动时的动态特性,为了验证模型的准确性进行了实车实验。结果表明该轮边电机传动系统的输出转矩发生考虑波动转矩后会较大影响整车加速和制动性能,常见车速的加速和减速性能会减弱5%,稳定行驶阶段差别不大。刚柔耦合模型能更准确地描述驱动系统及整车动力特性,对整车的设计有指导意义。     

电动轮驱动的电动汽车动力学仿真

采用自然坐标系下的整车动力学模型,模拟变速或转向过程中可能存在的变化情况,进行了四电动轮独立驱动的电动汽车仿真。仿真试验表明,在变速或转向的过程中,各轮的输出转矩可能会有较大差异。因此在此类电动汽车的设计中应当充分考虑对变速或转向时各轮的转矩加以控制,以提高操控性能。     

Lateral handling improvement with dynamic curvature control for an independent rear wheel drive EV

The integrated longitudinal and lateral dynamic motion control is important for four wheel independent drive (4WID) electric vehicles. Under critical driving conditions, direct yaw moment control (DYC) has been proved as effective for vehicle handling stability and maneuverability by implementing optimized torque distribution of each wheel, especially with independent wheel drive electric vehicles. The intended vehicle path upon driver steering input is heavily depending on the instantaneous vehicle speed, body side slip and yaw rate of a vehicle, which can directly affect the steering effort of driver. In this paper, we propose a dynamic curvature controller (DCC) by applying a the dynamic curvature of the path, derived from vehicle dynamic state variables; yaw rate, side slip angle, and speed of a vehicle. The proposed controller, combined with DYC and wheel longitudinal slip control, is to utilize the dynamic curvature as a target control parameter for a feedback, avoiding estimating the vehicle side-slip angle. The effectiveness of the proposed controller, in view of stability and improved handling, has been validated with numerical simulations and a series of experiments during cornering engaging a disturbance torque driven by two rear independent in-wheel motors of a 4WD micro electric vehicle.     

A Fuzzy Logic Direct Yaw-Moment Control System for All-Wheel-Drive Electric Vehicles

Summary In-wheel-motors are revolutionary new electric drive systems that can be housed in vehicle wheel assemblies. Such E-wheels permit packaging flexibility by eliminating the central drive motor and the associated transmission and driveline components, including the transmission, the differential, the universal joints and the drive shaft. Apart from many advantages of such a system, unequalled independent wheel control allows vehicle dynamic improvement to assist the driver in enhancing cornering and straight-line stability on slippery roads and in adverse ground conditions. In this paper a Fuzzy logic driver-assist stability system for all-wheel-drive electric vehicles based on a yaw reference DYC is introduced. The system assists the driver with path correction, thus enhancing cornering and straight-line stability and providing enhanced safety. A feed-forward neural network is employed to generate the required yaw rate reference. The neural net maps the vehicle speed and the steering angle to give the yaw rate reference. The vehicle true speed is estimated using a multi-sensor data fusion method. Data from wheel sensors and an embedded accelerometer are fed into an estimator, where a Fuzzy logic system decides which input is more reliable. The efficiency of the proposed system is approved by conducting a computer simulation. The proposed control system is an effective and easy to implement method to enhance the stability of all-wheel-drive electric vehicles.     

A Fuzzy Logic Direct Yaw-Moment Control System for All-Wheel-Drive Electric Vehicles

Summary In-wheel-motors are revolutionary new electric drive systems that can be housed in vehicle wheel assemblies. Such E-wheels permit packaging flexibility by eliminating the central drive motor and the associated transmission and driveline components, including the transmission, the differential, the universal joints and the drive shaft. Apart from many advantages of such a system, unequalled independent wheel control allows vehicle dynamic improvement to assist the driver in enhancing cornering and straight-line stability on slippery roads and in adverse ground conditions. In this paper a Fuzzy logic driver-assist stability system for all-wheel-drive electric vehicles based on a yaw reference DYC is introduced. The system assists the driver with path correction, thus enhancing cornering and straight-line stability and providing enhanced safety. A feed-forward neural network is employed to generate the required yaw rate reference. The neural net maps the vehicle speed and the steering angle to give the yaw rate reference. The vehicle true speed is estimated using a multi-sensor data fusion method. Data from wheel sensors and an embedded accelerometer are fed into an estimator, where a Fuzzy logic system decides which input is more reliable. The efficiency of the proposed system is approved by conducting a computer simulation. The proposed control system is an effective and easy to implement method to enhance the stability of all-wheel-drive electric vehicles.     

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。     

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。     

独立悬架-电动轮模块的双横臂悬架机构设计

四轮驱动电动汽车采用由轮毂电机、转速传感器、制动盘和双横臂悬架机构组成的结构相同的独立悬架-电动轮模块，可大幅度减少零部件种类，降低制造成本。文中按空间机构理论导出了双横臂悬架导向机构运动分析与设计的基本公式，并研制成简明实用的视窗式分析与设计系统。提出了可完全消除附加转向干涉的非转向轮双横臂悬架导向机构。将这些研究成果具体应用于国内第一台四轮驱动燃料电池微型汽车概念平台“春晖一号”和样车“春晖二号”的研制，取得了良好效果。