集成转向传感器的设计

设计了一种安装于汽车转向柱的磁阻式非接触转矩/转角集成转向传感器,它是将转矩/转角两种传感器集成为一体,使用磁敏器件作为敏感元件,单片机实现对转矩/转角的同时测量。并进行了传感器的标定试验,得到了可靠数据。     

汽车EPS磁阻式转矩传感器的研制

在分析国内EPS系统转矩传感器研究现状基础上,设计了一种基于各向异性磁阻效应理论的非接触式转向盘转矩传感器.通过标定试验建立了该传感器转矩与磁场角度的关系.并在硬件在环试验台上对其功能进行验证.试验分析表明,所设计转矩传感器综合性能能够满足EPS系统的要求.     

陆地巡洋舰ABS制动跑偏三例

在陆地巡洋舰车型中,选装了 ABS系统。在维修中,先后遇到三例 ABS 制动跑偏故障,逐一介绍。例一、传感器更换错误该车以前 A B S 系统正常,曾经ABS故障灯亮,到当 地丰田维修站检查,更换ABS右前车速传感器后 ABS 警告 灯亮灭正常,制动严重向左跑偏,进多家维修站维修,未 能解决。故障诊断:　首先进行初步检查。打开点火开关至 ON 位置,ABS警告灯点亮,几秒 钟后熄灭,ABS 系统自检正常。路试,车辆严重向左跑偏,解除ABS控制,制动正常。拆下右前轮车速传感器,发现传感器磁铁与对应的半轴转子在安装后并不平行,而是垂直。与左前车速传…     

2010款宝马Z4转向角异常报警

车型:E89. 行驶里程:25991km. 故障现象:车辆由于行驶中DSC故障灯点亮报警,并且车辆行驶中有点跑偏. 故障诊断:接车后首先连接ISID进行诊断测试,读取故障内容为5EC1-DSC转向角传感器可信度.执行检测计划,然后更换了转向角传感器(SZL),对全车进行编程设码,再对SZL中转向角传感器的匹配.最后进行路试,故障灯再次点亮报警,读取的故障内容与原来一样.为什么DSC的故障灯报警,读取的故障内容却是转向角信号可信度,又怎么会引起车辆行驶中跑偏呢?这得从转向柱开关中心SZL功能作用讲起.     

EPS用永磁同步电机准无位置传感器控制

提出一种准无位置传感器控制方法,用于电动助力转向系统用永磁同步电机转矩的控制。该方法采用霍尔传感器对D状态观测器位置估算值进行校正和补充,省略了高分辨率位置传感器及信号处理电路,降低了硬件成本。通过D状态观测器和霍尔传感器两个位置估算值的信号冗余,提高了系统的可靠性。仿真结果表明:采用该控制方法使电机转矩波动指标达到电动助力转向系统的要求。     

非接触式扭矩传感器在EPS中的应用

介绍非接触式扭矩传感器的基本结构和原理;通过对该传感器在EPS系统应用中出现跑偏问题的分析和改进．使非接触式扭矩传感器构成的EPS系统更趋于实用和完善。     

途观车行驶时向右跑偏

<正>故障现象一辆上海大众途观车,行驶里程约为3.2万km,因行驶时方向向右跑偏而进厂检修。故障诊断接车后试车验证故障,确实存在向右跑偏的故障现象。本着由简到繁的故障诊断原则,首先对车辆进行常规检查。检查各车轮的轮胎压力,正常;检查各轮胎的花纹及磨损情况,未见异常;对车辆进行四轮定位,发现前后轮的前束值均存在一定偏差,调整前束后试车,故障依旧。连接故障检测仪,对转向角度传感器进行基本设定后试车,发现当车辆保持直线行驶时,转向盘始终向右侧偏转一定角度。于是,维修人员将车辆开回修理r将转向盘向左转动约6°后,再次对转向角度传感器进行基本设定,试图纠正车辆向右跑偏的情况。设定完成后试车,发现     

渐入家境

EPS是英文Electric Power Steering的缩写,即“电动助力转向系统”,它一般出机械转向系统加上转矩传感器、车速传感器、电子控制单元、减速器、电动机等组成。、它在传统机械转向系统的基础上,根据方向盘上的转矩信号和汽印的行驶车速信号,利用电子控制装鼹使电动机产生稠应大小和方向的辅助动力,协助驾驶员进行转向操作。     

EPS用永磁同步电机电流传感器零点在线标定策略

电流传感器的零点漂移往往会造成永磁同步电机输出转矩的波动.文中在分析零点漂移所造成影响的基础上,提出了一种通过对采样电流的频率分析进行电流传感器零点在线标定的策略.该策略仅需电流传感器输出信号及电机转速即可对误差进行识别,并依靠事先制定的调整策略消除传感器零点漂移.     

永磁同步电机转矩控制精度范围影响因素分析及计算

为实现永磁体供货偏差、永磁体温度偏差、电流传感器精度偏差、电压传感器精度偏差、标定温度管理偏差和初始角检测偏差综合作用条件下的电驱动系统转矩控制精度计算，通过仿真和试验获得各因素单独作用下的影响因子，运用统计学原理获得综合各影响因素的转矩控制精度范围，并在样机上进行试验验证，结果表明，采用该方法计算获得的转矩值精度在-1.1%～2.8%范围内，满足产品要求。     

Estimation of trailer off-tracking using visual odometry

High-capacity vehicles have been shown to be highly effective in reducing emissions associated with road freight transport. However, the reduced manoeuvrability of long vehicles often necessitates the use of active trailer steering. Path-following trailer steering systems are very effective in this regard, but are currently limited to on-highway applications due to the manner in which trailer off-tracking is estimated. In this work, a novel trailer off-tracking measurement concept is introduced which is independent of wheel slip and ground surface conditions, and requires no additional sensor measurements or parameter data from the tractor. The concept utilises a stereo camera pair affixed to the trailer and a visual odometry-based algorithm to calculate off-tracking. The concept was evaluated in detailed simulation and full-scale vehicle tests, demonstrating its feasibility and highlighting some important characteristics. RMS measurement errors of 0.11–0.12?m (3.3–3.6%) were obtained in a challenging visual environment.     

在生产中对汽车行驶跑偏的分析与控制

对生产中刚下线有行驶跑偏问题的汽车进行了多项分析试验,通过试验,分析行驶跑偏产生的原因,提出了在生产中控制新车行驶跑偏缺陷的方法。     

沥青混凝土摊铺机液压故障及排除

根据多年维修保养沥青混凝土摊铺机所积累的经验,以ABG423沥青混凝土摊铺机和S1800沥青混凝土摊铺机为例,对摊铺机液压系统常见的液压油过热、螺旋布料器不能正常工作、熨平板提升困难、摊铺机跑偏或不行走和料斗不能正常合拢等故障进行了分析,并从若干方面提出排除方法和维修保养注意事项,对以后机械类似故障的维修具有一定的参考价值。     

半挂车承载轴偏斜角对车辆行驶性能影响及检测方法研究

半挂车承载轴偏斜会造成汽车的偏驶现象,为保持半挂车具有良好的技术状况,使其安全、低消耗的运行,最有效办法就是定期对半挂车承载轴进行检测和维修。在分析了半挂车承载轴偏斜角产生的原因及其对车辆使用性能影响的基础上,采用激光测距仪测出左右车轮边缘到半挂车铰接点的水平距离和光电编码器测出激光测距仪所转动的角度,利用距离和角度关系,建立了半挂车承载轴偏斜角的检测数学模型,通过研究,提出了承载轴偏斜角对车辆行驶性能评价的检测方法,为进一步研究承载轴偏斜对半挂车性能的影响提供了理论依据。     

Effects of multiple axles on the lateral dynamics of multi-articulated vehicles

This paper describes an analytical study of the lateral dynamics of multi-articulated vehicles with multiple axles. A linear planar model of vehicle dynamics is adopted for multiple-axle vehicle combinations with an optional number of trailers. Two tractor and double-trailer combinations are examined for their directional stability and response. Non-oscillatory stability and steering sensitivity in steady-state turning and lane changing are analysed using a stability factor of multiple-axle vehicle combinations. Off-tracking in the steady-state turning of multiple-axle vehicle combinations is also analysed. Numerical calculations for oscillatory stability, steering sensitivity, and off-tracking are presented for multiple-axle vehicle combinations.     

On the sway stability improvement of car–caravan systems by articulated connections

The present analysis is addressed to some promising connection arrangements between the towing vehicles and the towed trailers, where the two units are linked by four-bar isosceles trapeziums in place of the conventional pintle hitch. Two types of instability, of the divergent type or the oscillating type, may be analysed by the Routh–Hurwitz criterion or by the direct analysis of the characteristic equation. The constant term of this equation vanishes at the divergent instability threshold (zero of a real root), whereas the equation splits into two lower degree algebraic ‘sub-equations’ when the oscillating instability arises (pair of pure imaginary roots). A large field of geometrical configurations of the four-bar linkage may be quickly tested by numerical search procedures, including those where the sidebars of the linkage converge towards the inside of the drawing car and shift the relative centre of rotation forward, and those converging backward towards the trailer. Maps of the critical velocity as a function of the geometrical or physical parameters may be easily traced. They clearly show the favourable influence of the forward four-bar connection in general and the benefits achievable comparing with the conventional coupling. Actually, it is conceivable to increase the critical speed by optimising the four-bar design depending on the weight distribution on the axles and on the other geometrical and physical properties. Moreover, this type of connection may produce significant corrections to the under-steering or over-steering conduct of the articulated vehicle. The off-tracking and the manoeuvrability along curved paths are also studied, showing the benefits or the drawbacks of the four-bar linkage for the various configurations.     

火花点火发动机爆震燃烧测量方法的初步研究

在一台发动机上利用光纤传感器、压力传感器、振动传感器等对火花点火发动机爆震燃烧进行控制研究，并对测试结果进行比较，同时探索了光纤传感技术在爆震测量中应用的可行性。研究结果表明，光纤传感器与压力传感器在爆震预测与识别上基本等效，但光纤传感器灵敏度与准确度较高，而且光纤传感器还有利于实现其它多项燃烧特性的测试，光纤传感器将成为电控技术中燃烧过程测控信号的重要手段。     

Travel time estimation oriented freeway sensor placement problem considering sensor failure

Optimal sensor placement on freeway corridor is of great interest to transportation authorities. However, current traffic sensors are easily subject to various failures. Therefore, it is necessary to incorporate sensor failure into the optimal sensor placement model. In this article, a two-stage stochastic model is proposed for the purpose of travel time estimation on freeway corridor. To balance the effectiveness and reliability, a stochastic conditional value at risk (CVaR) model is also proposed. Since both models are too complicated, a customized genetic algorithm is developed. Numerical experiments show that considering sensor failure makes a significant performance improvement in the sensor placement pattern. Sensitivity analysis is also applied to investigate the impact of a number of allowable sensors and different traffic sensor failure probability.     

Low cost design of parallel parking assist system based on an ultrasonic sensor

This paper presents a low cost design and implementation of a parallel parking assist system (PPAS) based on ultrasonic sensors. Generally, a PPAS requires several types of sensors, such as an ultrasonic sensor, camera sensor, radar sensor and laser sensor for parking space detection. However, our proposed PPAS only requires two ultrasonic sensors on the front and lateral sides for parking space detection. Moreover, a steering angle sensor and wheel speed sensor installed in the vehicle are used to obtain vehicle position information for localization in ultrasonic range data. The hardware architecture of the PPAS based on an electronic control unit (ECU) module, sensor modules and a human machine interface (HMI) module was proposed. Moreover, the software architecture of the PPAS is based on system initialization, scheduling, recognition and a control algorithm. In particular, a novel sensor algorithm was proposed to minimize the vehicle corner error of the ultrasonic sensor. A prototype of the PPAS based on the proposed architecture was constructed. The experimental results demonstrate that the implemented prototype is robust and successfully performs parking space detection and automatic steering control. Finally, the low cost design and implementation of the PPAS was possible due to the cheap ultrasonic sensors, simple hardware design and low computational complexity of the proposed algorithm.     

Parallel model based fault detection algorithm for electronic parking brake system

This paper describes a parallel model-based fault detection algorithm for an electronic parking brake (EPB) system, which consists of an electronic control unit with built-in current sensor and braking force sensor. For the EPB system to supply sufficient parking force to a vehicle, the parking force sensor is of utmost importance. If a fault occurs in this sensor, sufficient parking force may not be supplied, thereby seriously threatening the safety of the vehicle. Thus, a fault detection method is required for the parking force sensor of the EPB system to improve the safety of vehicles. For this purpose, a highly reliable fault detection method is needed to detect abnormal fault signals, which cannot be detected by the existing on-line sensor monitoring fault detection methods. This paper proposes a novel parallel model-based fault detection algorithm for the EPB system, which compares the physical sensor data with the mathematical model, the fuzzy model, and the neural network model at the same time. In order to reduce false alarms, the magnitude of thresholds and the operation counts are changed adaptively. When the proposed parallel model-based fault detection algorithm detects severe failures of the force sensor, it warns the driver in advance to prevent accidents due to the failures. The proposed algorithm is verified by hardware-in-theloop simulations in various situations.