四轮独立驱动纯电动汽车驱动防滑控制

本文研究四轮独立驱动(4WID)纯电动汽车的驱动防滑(ASR),提出基于门限角加速度和滑转率的模糊滑转率控制方法。利用4WID电动汽车驱动力矩独立可控,转速和驱动力矩容易获得的特点,以实际角加速度与门限角加速度之差和实际滑转率作为模糊控制器输入,使得实际角加速度接近门限角加速度,控制各轮的驱动力矩实现驱动防滑。与PID控制进行对比,仿真结果表明,基于门限角加速度的模糊滑转率控制,能有效的降低滑转率,抑制驱动轮的滑转,提高了电动汽车在低附着路面加速行驶的稳定性和安全性。     

基于卡尔曼滤波的4WD电动车辆寄生功率的测量技术

根据串励直流电动机工作特性,利用车辆行驶过程中较易测得的驱动电机工作电流及驱动轮转速,运用MATLAB/SIMULINK软件,建立基于卡尔曼滤波的驱动轮滑转率模型和寄生功率模型并进行仿真;通过道路试验对电动机工作电流和驱动轮转速的检测,实时预测驱动轮的滑转率与产生的寄生功率。结果表明,驱动轮滑转率和寄生功率的仿真结果与试验结果非常接近。     

压力钢带式CVT滑转率理论分析与精确测算方法研究

针对滑转率现有的测量方法和汁算方法的不足,分析了产生测量和计算偏差的原因,将金属带回转中心的偏移理论引入到滑转毕的计算模型中,提出了一种新的滑转率测量与计算模型.并以该模型为基础设计了滑转率测量试验装置.试验结果表明,新的测箅模型达到了纠正原有方法偏差、实现高精度测算CVT滑转率的目标.     

轮式工程机械行走机构滑转现象研究

轮式工程机械行走机构的滑转现象是复杂的物理现象,其滑转特性是机械牵引性能的主要参数。文中根据滑转现象的不同物理机理,将行走机构滑转现象划分为相应的5种滑转率,可为获取行走机构的滑转特性和建立其物理机理相应的数学模型提供可靠的理论依据。     

驱动防滑控制系统(TRC)

汽车"打滑"有两种情况:一是制动时的车轮滑移;二是汽车驱动时的车轮"滑转".车轮"滑转"可以用滑转率S表示.     

转向加速工况下汽车驱动防滑控制系统滑转率算法研究

汽车低速转弯加速时,用后轮轮速作为参考车速计算驱动轮滑转率会造成计算偏差,引起驱动防滑控制系统误干预,为此提出了驱动轮滑转率计算的修正算法.该修正算法不需要增加前轮转角传感器,而是采用两非驱动轮轮速估计车身横摆角速度和汽车前轮转角,进而计算出前轮参考轮速,并将前轮参考轮速代替车速对转弯工况的驱动轮滑转率计算进行修正.试验结果表明,该修正算法消除了滑转率计算误差,可防止汽车在高附着路面上转弯加速时驱动防滑控制系统的误干预.     

基于dSPACE的ASR硬件在环仿真平台开发及ECU性能试验

简述了ASR硬件在环仿真平台的基本组成和工作原理,利用dSPACE实时仿真系统与所建立的车辆模型连接构成了ASR ECU硬件在环仿真系统.在该系统上验证了所开发ASR ECU的控制逻辑并对其参数进行了优化.将利用硬件在环仿真技术开发的ECU安装在某轻型车辆上进行试验,结果表明,该车驱动轮的过度滑转情况得到抑制;该系统可较好地模拟车辆系统和试验环境,并可替代部分实车试验.     

越野汽车TCS冰雪道路试验研究

针对自主开发的越野汽车牵引力控制系统（TCS）进行了冰雪路面加速道路试验研究，完成了实际“驾驶员-车辆-道路”闭环环境下的TCS的软、硬件匹配。试验结果表明：牵引力控制系统能够有效消除驱动轮过度滑转，显著改善汽车的加速性和方向稳定性。     

汽车传动系自激扭振机理研究

本文对汽车传动产生自激振动的机理进行了系统的理论分析与试验研究，提出当滑转率超过起振滑转率门槛值时传动系能产生硬激励特性的自激振动，并研究了自激振动系统的能量反馈与控制环节，为抑制自激振动提供理论根据。     

驱动转向复合工况分布式驱动稳定控制开发与验证

为在驱动转向复合工况下有效抑制分布式驱动电动汽车的纵滑、侧滑,提出了一种面向驱动转向复合工况的分布式驱动稳定控制架构,设计基于横摆角速度和侧偏角跟踪控制的横摆控制策略和基于滑转率跟踪控制的驱动防滑控制策略,同时根据转向稳定状态对目标滑转率进行调节,根据车辆行驶状态对横摆控制与驱动防滑控制输出扭矩进行协调优化,以实现车辆...     

Coordinated vehicle traction control based on engine torque and brake pressure under complicated road conditions

Vehicle traction control system has been developed to enhance the traction capability and the direction stability of the driving wheels through the tyre slip ratio regulation. Under normal situations, if the tyre slip ratio exceeds a certain threshold, the slip ratio of the driving wheel is regulated by the coupled interaction of the engine torque and the active brake pressure. In order to obtain the best driving performance on a road under complicated friction conditions, the driving torque and the active brake pressure, need to be decoupled and adjusted to avoid penalisation of each other. In this paper, a coordinated cascade control method with two sliding-mode variable structure controllers is presented. In this control method, the driving wheel slip ratio is regulated by adjusting the engine torque and the wheel brake pressure. Through the sliding-mode controller, the engine torque is tuned to achieve the maximum driving acceleration and then the active brake pressure is applied to the slipped wheel for further modification of the wheel slip ratio. The advantage of this control method is that through proper regulation, the conflict between the two control inputs could be avoided. Finally, the simulation results validate the effectiveness of the proposed method.     

Vehicle velocity estimation using effective inertia for an in-wheel electric vehicle

In this study, a vehicle velocity estimation algorithm for an in-wheel electric vehicle is proposed. This algorithm estimates the vehicle velocity using the concept of effective inertia, which is based on the motor torque, the angular velocity of each wheel and vehicle acceleration. Effective inertia is a virtual mass that changes according to the state of a vehicle, such as acceleration, deceleration, turning or driving on a low friction road. The performance of the proposed vehicle velocity estimation algorithm was verified in various conditions that included straight driving, circle driving and low friction road driving using the in-wheel electric vehicle that was equipped with an in-wheel system in each of its rear wheels.     

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.     

基于车辆稳定性的改扩建高速公路横坡方案安全性评价研究

针对改扩建高速公路单侧加宽方案老路利用时可能存在的行车稳定性问题,应用基于车辆动力学的建模仿真方法,采用联合仿真技术,在Carsim/Trucksim仿真软件中得到车辆在横坡组合路段行驶过程中车轮的垂直载荷与车辆侧向加速度;在Simulink中计算车辆的横向载荷转移率和侧向加速度;通过上述指标分析车辆横向侧翻和侧滑稳定性,判断车辆在改扩建公路横坡组合路段上的行驶稳定性;联合仿真结果表明,车辆在横向坡度为2%和1.5%、换道路长为120 m和80 m的横坡组合路段上行驶均具有良好的横向稳定性;该方法可用于其他道路和驾驶行为的车辆稳定性分析.      

Nonlinear Dynamics of Vehicle Traction

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.     

Nonlinear Dynamics of Vehicle Traction

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.     

基于模糊控制方法的防抱控制系统的研究

本文采用模糊控制方法对车辆防抱制动系统进行了模拟研究，采用单轮的车辆模拟模型，用两种方法研究了防抱系统，即基于车轮滑移率的连续控制系统和基于车轮加减速度及参考滑移率的非连续控制系统。     

汽车防抱制动系统车速估计方法的初步研究

实现基于滑移率控制的汽车防抱制动系统的前提是车速的准确测量。为减少微控制器的计算量和增加系统可靠性，利用汽车轮速信号和车身加速度信号，建立了估计车速的线性模型，提出了模型中系数的基于最小二乘递推算法的计算方法。试验结果验证了该方法的可行性和有效性。     

Development of a new traction control system for vehicles with automatic transmissions

A traction control system (TCS) is used to improve the acceleration performance on slippery roads by preventing excessive wheel slip. In this paper, a new traction control system using the integrated control of gear shifting and throttle actuation is developed for vehicles with automatic transmissions. In the design of the slip controller, by means of a differential manifold transformation, a slip control system with nonlinearities and uncertainties is transformed into a linear system, and a sliding mode controller is applied for the purpose of increasing the robustness of the system. Next, to achieve the required driving torque, the optimal throttle and gear position, maps are constructed based on dynamic programming. The simulation results indicate that the present traction control system can improve the acceleration performance of an automatic transmission vehicle for various types of road conditions.