串联式混合动力多轴独立驱动车辆的电机驱动系统设计

混合动力汽车具有低排放、省油等特点,引起汽车界极大关注并成为汽车开发的一个热点。本文介绍了串联式混合动力三轴独立驱动车辆的电机驱动系统设计,包括了基于CAN总线的多轮驱动系统基本结构、多轴电机驱动力分配策略、单电机驱动系统的硬件电路设计和基于转子磁场定向的矢量控制。最后给出三轴六轮车辆在加速、制动等不同工况下的三电机运行特性结果,实验结果表明该多电机驱动控制系统基本满足车辆运行的基本需求。     

实时汽车电子辅助制动控制系统的设计研究

针对传统电子辅助制动方法需要结合驾驶员操纵来实现制动操作,研究了一种实时电子辅助制动系统,该系统采用电子感应传感器与高速芯片组成硬件系统,使用OMAP-L137芯片作为中央处理器,使用MSP430F169芯片作为制动等功能模块的实时处理器,OMAP-L137芯片与各个MSP430F169芯片之间通过CAN总线进行数据传输。同时使用基于考虑车辆安全性能和舒适性能的发动机辅助接入时机控制策略、BSG电机和离合器协调策略以及TM电机的转矩控制策略作为实时电子辅助制动系统的核心控制策略。最后,通过实验对研究的实时电子辅助制动系统的性能进行实验研究,结果表明在使用了该系统后,对于提高乘坐舒适性以及提高汽车驱动系统寿命都是十分有益的。     

全电驱分布式无人车路径跟踪控制仿真研究

为实现全电驱分布式无人车的路径跟踪控制仿真,联合Carsim和Simulink建立了具备独立驱动/制动/转向功能的全电驱分布式无人车运动仿真平台.在该仿真方法中,车辆行驶的整车动力学仿真在Carsim软件中实现,整车动力学中驱动轮的驱动力矩及转速等参数直接来自Matlab/Simulink中建立的驱动电机、转向电机等驱...     

基于VB的汽车制动系统仿真设计研究

为了方便设计不同车型、不同制动器结构形式的制动部件,提出了汽车制动系统仿真设计方法,并开发了计算通用程序软件。该软件主要对真空助力器、比例阀、制动主缸、制动轮缸等制动部件参数进行计算设计,以满足整车的安全性能要求,具有效率高、准确的优点。该系统不仅可以为汽车零部件生产厂家提供产品生产参数而且为汽车检测部门提供检测性能的参考依据。     

电子机械制动系统的设计与应用研究

电子机械制动系统是汽车中不可或缺的一个重要控制系统,该系统的性能稳定与否直接关系到车辆的运行安全性。为此,在对该系统进行设计时,应当充分考虑车辆的安全运行需要,同时还要保证系统自身运行的可靠性。基于此点,本文首先简要阐述了电子机械制动系统的基本设计要求,在此基础上重点对电子机械制动系统关键模块的设计进行论述。期望通过本文的研究能够对车辆制动性能的提升有所帮助。     

基于嵌入式的汽车辅助制动系统研究

针对传统汽车电子辅助制动系统主要由驾驶员主观意识对制动进行控制,车辆并不能根据车辆的实时状态进行辅助制动控制,存在极大安全隐患的问题,研究一种基于嵌入式的汽车辅助制动系统。其主要由车轮速度检测、车身加速度检测、方向盘转角检测、制动踏板压力检测、车身姿态检测等信号检测模块、车辆制动执行模块以及中央处理器和辅助接口模块等组成。针对基于嵌入式的汽车辅助制动系统的硬件组成、嵌入式系统通信方案和主要功能模块等设计进行了详细叙述。实验结果表明该设计达到了预期目标。     

汽车防抱死制动系统常见故障诊断

制动系统是汽车的一个重要组成部分,是保证行车安全极为重要的一个系统,它的好坏直接影响车辆的平均车速和车辆的运输效率。为保证制动效果的有效发挥;为保证汽车紧急情况具有转向操作能力;为提高车辆的安全性能,故在车辆内部加装了防抱死制动系统(简称ABS)。本文对汽车防抱死系统的组成、工作原理及常见故障进行分析、排除诊断。     

论车辆制动灯的检查电路原理

现如今为了满足人们对汽车安全性能方面的需求,我们有必要根据我国现行的车辆制动灯相关法律规定,进行便于驾驶员检查的制动灯检查电路方面的研究。     

浅析单片机在汽车制动性能检测系统中的应用

随着科学技术的快速发展,汽车已经渗透到人们生活的各个领域。随着汽车数量的不断增加,随之出现的安全问题也越来越多。因此,单纯地依靠汽车本身的机构来保证行车安全,是不全面的,必须强化对车辆上涉及安全的部位,在一定的时间内进行检测,并根据相应的标准来检测这些部件的性能,科学、恰当地给出车辆是否安全的评估结果。本文的主要内容是研究单片机在汽车制动性能检测系统中的基本应用。     

基于ARM7的底片数字化仪电机同步驱动设计

针对焊缝缺陷X射线实时自动检测技术普遍存在误检高的问题,研制了钢管焊缝缺陷X射线实时自动检测系统,本文提出了工业胶片智能检测系统中采集和控制的同步问题的研究方法,设计了步进电机的控制方法与光电编码器采集方法,通过超低功耗系列单片机LPC2114进行步进电机速度的采集与电机速度PID控制,同时,步进电机带动夹持机构使胶片相对CCD运动,线阵CCD开始采集图像。只要CCD的线频率与扫描机构的运动速度同步,就可以采集到没有畸变的图像,运用LMD18245全桥电机驱动器等器件以及设计所需的相关软件的使用。在此基础上,对系统进行设计、编程和调试,该系统在压力管道焊缝缺陷实时自动检测中验证了其正确性和有效性。     

Longitudinal wheel slip control using dynamic neural networks

The control of automotive braking systems performance and a wheel slip is a challenging problem due to nonlinear dynamics of a braking process and a tire–road interaction. When the wheel slip is not between the optimal limits during braking, the desired tire–road friction force cannot be achieved, which influences braking distance, the loss in steerability and maneuverability of the vehicle. In this paper, the new approach, based on dynamic neural networks, has been employed for improving of the longitudinal wheel slip control. This approach is based on dynamic adaptation of the brake actuation pressure, during a braking cycle, according to the identified maximum adhesion coefficient between the wheel and road. The brake actuated pressure was adjusted on the level which provides the optimal longitudinal wheel slip versus the brake actuated pressure selected by a driver, the current vehicle speed, load conditions, the brake interface temperature and the current value of the wheel slip. The dynamic neural network has been used for modeling of a nonlinear functional relationship between the brake actuation pressure and the longitudinal wheel slip during a braking cycle. It provided preconditions for control of the brake actuation pressure based on the wheel slip change.     

Real-time slip-based estimation of maximum tire-road friction coefficient

This paper presents a real-time maximum tire-road friction coefficient estimation method and field test results. The estimator is based on the relationship between the wheel slip ratio and the friction coefficient. An effective tire radius observer and a tire normal force observer have been designed for the computation of the slip ratio from wheel speed and vehicle speed measurements. The effective tire radius observer has been used so that the proposed method works for all driving situations. A tractive force estimator, a brake gain estimator, and a normal force observer have been used for the estimation of the friction coefficient. The proposed estimation method for the maximum tire-road friction coefficient has been implemented using a fifth wheel and typical vehicle sensors such as engine speed, carrier speed, throttle position, and brake pressure sensors.     

Vehicle motion control with subsystem prioritization

This paper presents a new approach for integrated vehicle motion control, coordinating multiple vehicle subsystems of a passenger car including friction brake system, near-wheel drive electric motors, wheel steer actuators, camber angle actuators, dynamic tire pressure system and actuators generating additional normal forces. The proposed algorithms are based on restriction weights into the cost function of optimization-based control allocation. Hardware-in-the-loop investigation using a test rig with hardware components of friction brake system and dynamic tire pressure system showed that the proposed approach allows to achieve lower energy consumption and energy losses without significant impairment of motion stability and vehicle handling as compared to conventional control allocation.     

Electric vehicles-pursuing efficiency

The approaches being used to make electric vehicles (EVs) highly efficient given the limitations of EV batteries are described. They include reducing vehicle weight, aerodynamic drag, tire rolling resistance, and bearing friction; eliminating brake drag; and increasing the efficiency of the electric motor and its control electronics. The intrinsic efficiency of electric motors and the choice of power electronics are discussed. Energy management and the use of regenerative braking are examined     

A fuzzy logic control for antilock braking system integrated in the IMMa tire test bench

The use of fuzzy control strategies has recently gained enormous acknowledgement for the control of nonlinear and time-variant systems. This article describes the development of a fuzzy control method for a tire antilock system in vehicles while braking, integrated in a tire test bench, thereby allowing us to imitate the functioning and to understand the behavior of these systems in a reliable way. One of the inconveniences found in the development of these systems has been the difficulty of adjustment to the real conditions of a functioning vehicle. The main advantage obtained when using the tire test bench is the possibility of being able to reproduce the conditions established as fundamental to the operation of the antilock brake system (ABS) in a reliable and repetitive way, and to adjust these systems until optimal performance is obtained. The fuzzy control system has been developed and tested in the tire test bench to be able to refine its fundamental parameters, obtaining adequate results in all the studied conditions. The ease of the bench for the development and verification of new control systems for ABS has been demonstrated.     

SS系列机车制动工况及轮对椭圆化在线监测的研究与实现

提出了一种ss系列机车制动工况及轮对椭圆化在线监测的研究,利用两个位移传感器实时检测制动器传动装置的位移量、车轮轮箍踏面的位移量,通过工控机计算以实现对制动工况中的缓解、制动情况、闸瓦磨损情况、轮箍磨损及轮对椭圆化情况的在线监测;以便于及时处理制动工况中的不良问题,保证行车的安全。通过MATLAB软件仿真了轮对椭圆化检测的变化曲线,验证了研究中对轮对椭圆化情况在线监测的可行性。     

Design considerations for an automotive magnetorheological brake

In this paper, design considerations for building an automotive magnetorheological (MR) brake are discussed. The proposed brake consists of multiple rotating disks immersed in a MR fluid and an enclosed electromagnet. When current is applied to the electromagnet, the MR fluid solidifies as its yield stress varies as a function of the magnetic field applied. This controllable yield stress produces shear friction on the rotating disks, generating the braking torque. In this work, practical design criteria such as material selection, sealing, working surface area, viscous torque generation, applied current density, and MR fluid selection are considered to select a basic automotive MR brake configuration. Then, a finite element analysis is performed to analyze the resulting magnetic circuit and heat distribution within the MR brake configuration. This is followed by a multidisciplinary design optimization (MDO) procedure to obtain optimal design parameters that can generate the maximum braking torque in the brake. A prototype MR brake is then built and tested and the experimental results show a good correlation with the finite element simulation predictions. However, the braking torque generated is still far less than that of a conventional hydraulic brake, which indicates that a radical change in the basic brake configuration is required to build a feasible automotive MR brake.     

Longitudinal vehicle state estimation using nonlinear and parameter-varying observers

A corner-based velocity estimation approach is proposed which is used for vehicle’s traction and stability control systems. This approach incorporates internal tire states within the vehicle kinematics and enables the velocity estimator to work for a wide range of maneuvers without road friction information. Tire models have not been widely implemented in velocity estimators because of uncertain road friction and varying tire parameters, but the current study utilizes a simplified LuGre model with the minimum number of tire parameters and estimates velocity robust to model uncertainties. The proposed observer uses longitudinal forces, updates the states by minimizing the longitudinal force estimation error, and provides accurate outcomes at each tire. The estimator structure is shown to be robust to road conditions and rejects disturbances and model uncertainties effectively. Taking into account the vehicle dynamics is time-varying, the stability of the observer for the linear parameter varying model is proved, time-varying observer gains are designed, and the performance is studied. Road test experiments have been conducted and the results are used to validate the proposed approach.     

Load sensing bearing based road-tyre friction estimation considering combined tyre slip

This work discusses a road-tyre friction estimator considering combined tyre slip. The friction estimator design is motivated by its importance in vehicle dynamics control as accurate friction estimation can improve performance and safety. The estimator uses tyre force measurements from Load Sensing Bearing (LSB) technology and does not rely on parameterized tyre model. The tyre force measurements benefit the estimator mainly because of the uncertainties and nonlinearities of the tyre force characteristics. The proposed estimator uses tyre slip and tyre force representations where the longitudinal and lateral tyre slips and forces are combined into a single tyre slip and tyre force values. This representation makes the method effective during pure longitudinal dynamics, pure lateral dynamics and for combined slip. In addition, individual tyre-road friction estimation is possible with the proposed estimator and a computationally inexpensive algorithm, suitable for real-time implementation, is used to estimate the friction. The estimator is studied in simulation during pure braking, pure cornering and for combined slip. Further, the estimator is simulated in closed loop with a yaw rate controller to study whether the estimator improves vehicle safety. Finally the estimator is validated using test data from several maneuvers performed on a test vehicle instrumented with LSB technology.