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1.
Summary The purpose of this study is to understand the nonlinear dynamics of longitudinal ground vehicle traction. Specifically, single-wheel models of rubber-tired automobiles under straight-ahead braking and acceleration conditions are investigated in detail. Customarily, the forward vehicle speed and the rotational rate of the tire/wheel are taken as dynamic states. This paper motivates an alternative formulation in which wheel slip, a dimensionless measure of the difference between the vehicle speed and the circumferential speed of the tire relative to the wheel center, replaces the angular velocity of the tire/wheel as a dynamic state. This formulation offers new insight into the dynamic behavior of vehicle traction. The unique features of the modeling approach allow one to capture the full range of dynamic responses of the single-wheel traction models in a relatively simple geometric manner. The models developed here may also be useful for developing and implementing anti-lock brake and traction control control schemes.  相似文献   

2.
Effect of Traction Force Distribution Control on Vehicle Dynamics   总被引:1,自引:0,他引:1  
The purpose of this study is to clarify vehicle dynamics effected by traction force distribution, not only between the front and rear wheels but also between the left and right wheels. Contribution of traction force distribution to vehicle turning performance was investigated using a mathematical simulation and an experimental vehicle. The results indicates that the control of traction control distribution between the left and right wheels greatly influences vehicle turning characteristics and improve the performance even in a marginal turning condition.  相似文献   

3.
SUMMARY

The purpose of this study is to clarify vehicle dynamics effected by traction force distribution, not only between the front and rear wheels but also between the left and right wheels. Contribution of traction force distribution to vehicle turning performance was investigated using a mathematical simulation and an experimental vehicle. The results indicates that the control of traction control distribution between the left and right wheels greatly influences vehicle turning characteristics and improve the performance even in a marginal turning condition.  相似文献   

4.
2.6.4动态牵引性能研究的启示 通过工程车辆动态牵引性能的研究总结给我们的启示是:根据机器牵引系统的结构,提高机器在动态负荷下工作性能的措施除了应保持各部件参数的合理匹配外,还有以下几个方面.  相似文献   

5.
工程车辆牵引动力学概述及其研究回顾(12)   总被引:2,自引:0,他引:2  
2.7.2 机械有级自动变速研究状况 机械自动变速器可分为液力自动变速器(AT)~I电控机械式自动变速器(AMT)。动力换档的AT与变矩器一起构成液力自动变速传动系统,用于牵引和运输车辆,机械换档的(ATM)主要用于机械传动的运输车辆。在液压传动的工程车辆上,AT和AMT均可应用.前者用于单马达驱动系统,后者则用于单马达与多马达的驱动系统。  相似文献   

6.
3.4牵引动力学模型的分析与总结 通过上述机器牵引系统各部件的运动方程式(1.50)~式(1.56)的联立求解,可以分析机器的各种工作状态,计算出相应的动态性能指标.对机器系统来说,输入为发动机的循环供油量△g=△g(h,ωe),或者说是供油拉杆的位移h(PT的压力pe);干扰有工作负荷Fx(t)和影响行走机构滑转性能的诸因素,在取静态滑转曲线计算时,干扰仅为工作负荷Fx(t);系统输出为牵引力fk(t)、行走速度V以及在此基础上计算的牵引功率NT、牵引效率ηT、牵引比油耗gT、牵引小时油耗GT等.  相似文献   

7.
工程车辆牵引动力学的研究分为2个阶段,即静态研究阶段和动态研究阶段。静态研究阶段主要集中在20世纪70年代以前,其主要方法是假定车辆为固定不变的负荷和地面条件,保持档位和发动机油门不变研究车辆在此静态条件下的性能以及车辆为达到最高的静态性能而应有的总体参数匹配方法与条件。其工况是静态,其方法是点工况参数匹配,不涉及到参数变化的过程问题。静态工况为一种假定工况,是对实际动态工况的高度抽象与假定,是为了简化问题而采取的一种近似方法。因此,静态性能并不能真实地描述车辆在实际的动态工况下的工作性能,其优化方法——固定参数匹配也不能使车辆在动态工况下达到最佳的性能。因此,自20世纪70年代以后,牵引动力学研究进入动态阶段,即研究车辆实际动态变负荷工况下的真实性能及其为达到最佳性能而应该采取的相关措施。  相似文献   

8.
3.3工程车辆动态分析与数学模型 3.3.1机器-地面系统结构框图 机器工作过程中承受的外部激励和内部干扰有:(1)机器操作工艺变化,主要是切削深度和运土量变化,它取决于驾驶员的操作方式和地面形状,基本构成负荷过程的确定性趋势项。  相似文献   

9.
因此,展开可调变矩器与液压传动系统在牵引式工程车辆上应用的研究将是今后的主要课题。与可调变矩器相比,液压传动元件经过数十年的发展,从性能、质量、批量配套、控制完善性以及价格等方面考虑均相对成熟。  相似文献   

10.
We present a brief outline of nonlinear dynamics and its applications to vehicle systems dynamics problems. The concept of a phase space is introduced in order to illustrate the dynamics of nonlinear systems in a way that is easy to perceive. Various equilibrium states are defined, and the important case of multiple equilibrium states and their dependence on a parameter is discussed. It is argued that the analysis of nonlinear dynamic problems always should start with an analysis of the equilibrium states of the full nonlinear problem whereby great care must be taken in the choice of the numerical solvers. When the equilibrium states are known certain linearizations around one chosen state may be applied carefully in order to facilitate or speed up the numerical solution of the dynamical problem. It is argued, however, that certain problems cannot be linearized. The applications of nonlinear dynamics in vehicle simulations is discussed, and it is argued that it is necessary to know the equilibrium states of the full nonlinear system before the simulation calculations are performed.  相似文献   

11.
We present a brief outline of nonlinear dynamics and its applications to vehicle systems dynamics problems. The concept of a phase space is introduced in order to illustrate the dynamics of nonlinear systems in a way that is easy to perceive. Various equilibrium states are defined, and the important case of multiple equilibrium states and their dependence on a parameter is discussed. It is argued that the analysis of nonlinear dynamic problems always should start with an analysis of the equilibrium states of the full nonlinear problem whereby great care must be taken in the choice of the numerical solvers. When the equilibrium states are known certain linearizations around one chosen state may be applied carefully in order to facilitate or speed up the numerical solution of the dynamical problem. It is argued, however, that certain problems cannot be linearized. The applications of nonlinear dynamics in vehicle simulations is discussed, and it is argued that it is necessary to know the equilibrium states of the full nonlinear system before the simulation calculations are performed.  相似文献   

12.
针对道路试验车辆和转鼓试验车辆分别建立了非线性动力学分析模型,通过仿真结果的对比分析阐明了转鼓试验可能导致的误差,进而通过对转鼓试验系统中车辆固定方式、非驱动轮胎固定方式、转鼓模拟转动惯量和动态响应控制标准的灵敏度仿真分析,指出了影响转鼓试验模拟精度的关键因素,提出了动态响应的改进和控制措施.  相似文献   

13.
SUMMARY

Recent developments in off-road vehicle dynamics are reviewed. Progress on this topic and the application of new techniques to the particular problemsassociated with off-road operation tend to lag behind practices established for road vehicles.

The factor which limits further progress is the lack ofappropriate off-road tyre data, in particular, on vibrational and lateral force generation characteristics. Also, a long term study should be aimed at understanding the dynamic behaviour of tyres on yielding surfaces.  相似文献   

14.
Off-Road Vehicle Dynamics   总被引:1,自引:0,他引:1  
Recent developments in off-road vehicle dynamics are reviewed. Progress on this topic and the application of new techniques to the particular problemsassociated with off-road operation tend to lag behind practices established for road vehicles.

The factor which limits further progress is the lack ofappropriate off-road tyre data, in particular, on vibrational and lateral force generation characteristics. Also, a long term study should be aimed at understanding the dynamic behaviour of tyres on yielding surfaces.  相似文献   

15.
车辆牵引力控制系统原型样机的开发研究   总被引:2,自引:0,他引:2  
在Matlab软件环境下,编写了牵引力控制算法原型,并搭建了车辆动力学仿真软件、硬件在环开发平台和车载快速开发平台。通过离线仿真、硬件在环试验以及道路试验调试控制算法,标定控制参数。最后以某后轮驱动汽车牵引力控制系统的分离路面试验研究为例进行了说明和验证。  相似文献   

16.
A temporal and spatial re-parameterization of the linear vehicle Bicycle Model is presented utilizing non-dimensional ratios of vehicle parameters called p-groups. Investigation of the p-groups using compiled data from 44 published sets of Vehicle Dynamics reveals a normal distribution about a line through p-space. The normal distribution suggests numerical-values for an 'average' vehicle and maximum perturbations about the average. A state-feedback controller is designed utilizing the p-space line and the expected p-perturbations to robustly stabilize all vehicles encompassed by the normal distribution of vehicle parameters. Experimental verification is obtained using a scaled vehicle.  相似文献   

17.
A temporal and spatial re-parameterization of the linear vehicle Bicycle Model is presented utilizing non-dimensional ratios of vehicle parameters called p-groups. Investigation of the p-groups using compiled data from 44 published sets of Vehicle Dynamics reveals a normal distribution about a line through p-space. The normal distribution suggests numerical-values for an ‘average’ vehicle and maximum perturbations about the average. A state-feedback controller is designed utilizing the p-space line and the expected p-perturbations to robustly stabilize all vehicles encompassed by the normal distribution of vehicle parameters. Experimental verification is obtained using a scaled vehicle.  相似文献   

18.
For the purposes of analyzing the stability and control properties of aircraft, automobiles, and ships, it is convenient to idealize the vehicle as a rigid body and to use a body-centered coordinate frame. A six-port bond graph is first developed which represents the nonlinear dynamics of a rigid body in a coordinate system rotating with the body. It is then shown how the graph simplifies if only lateral or longitudinal dynamics are studied. Finally, bond graphs for the type of stability studies in which the assumption of small perturbations permits linearization are shown for elementary models of automobiles and aircraft.  相似文献   

19.
SUMMARY

For the purposes of analyzing the stability and control properties of aircraft, automobiles, and ships, it is convenient to idealize the vehicle as a rigid body and to use a body-centered coordinate frame. A six-port bond graph is first developed which represents the nonlinear dynamics of a rigid body in a coordinate system rotating with the body. It is then shown how the graph simplifies if only lateral or longitudinal dynamics are studied. Finally, bond graphs for the type of stability studies in which the assumption of small perturbations permits linearization are shown for elementary models of automobiles and aircraft.  相似文献   

20.
Non-linearities in Road Vehicle Dynamics   总被引:1,自引:0,他引:1  
In the study of lateral vehicle dynamics with the objective to enhance stability and handling qualities, non-linear aspects may have to be included to cover also larger lateral accelerations and amplitudes. The paper treats whole vehicle motions and relative motions of vehicle subsystems. In particular, single car stability, also in the large, is discussed as well as the shimmy phenomenon and the car-trailer instability.  相似文献   

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