Nonlinear sliding mode observer for exhaust manifold pressure estimation in a light-duty diesel engine

In this paper, a sliding mode observer is proposed to estimate exhaust pressure for a diesel engine equipped with variable geometry turbocharger (VGT) and exhaust gas recirculation (EGR) systems. Since the exhaust pressure directly affects generation of the VGT power and the EGR rate in the cylinder, the exhaust pressure information is important for precise control of the VGT and EGR systems. In order to estimate the exhaust pressure accurately, a dynamic model of intake and exhaust pressure was derived. Furthermore, the mass flow rate and temperature of the air system in the diesel engines were modeled by consideration of physical phenomena and the thermodynamic law. Based on the developed models, a nonlinear sliding mode observer was designed to estimate the exhaust pressure. Convergence of the proposed observer was verified by the Lyapunov stability criterion. The proposed observer was implemented on a real-time embedded system and validated with the engine experiments. The experimental results show that the observer estimates the exhaust pressure accurately in both steady and transient engine operating conditions. Moreover, as a case study, the estimation results of the proposed observer could be applied for detecting a fault of the EGR system. The fault of the EGR system was detected precisely using the estimation result and the limited sensor information in mass-produced engines.     

Neural-network multiple models filter (NMM)-based position estimation system for autonomous vehicles

A highly accurate and reliable vehicle position estimation system is an important component of an autonomous driving system. In generally, a global positioning system (GPS) receiver is employed for the vehicle position estimation of autonomous vehicles. However, a stand-alone GPS does not always provide accurate and reliable information of the vehicle position due to frequent GPS blockages and multipath errors. In order to overcome these problems, a sensor fusion scheme that combines the data from the GPS receiver and several on-board sensors has been studied. In previous researches, a single model filter-based sensor fusion algorithm was used to integrate information from the GPS and on-board sensors. However, an estimate obtained from a single model is difficult to cover the various driving environments, including urban areas, off-road areas, and highways. Thus, a multiple models filter (MMF) has been introduced to address this limitation by adapting multiple models to a wide range of driving conditions. An adaptation of the multiple model is achieved through the use of the model probability. The MMF combines several vehicle models using the model probabilities, which indicate the suitability of the current driving condition. In this paper, we propose a vehicle position estimation algorithm for an autonomous vehicle that is based on a neural network (NN)-based MMF. The model probabilities are determined through the NN. The proposed position estimation system was evaluated through simulations and experiments. The experimental results show that the proposed position estimation algorithm is suitable for application in an autonomous driving system over a wide range of driving conditions.     

Fault detection method for electric parking brake (EPB) systems with sensorless estimation using current ripples

A fault detection method with parity equations is proposed in this paper. Due to its low cost implementation, the velocity of the motor is not measurable in electric parking brake (EPB) systems. Therefore, residuals are not reliable when estimating the motor velocity with a low-resolution encoder. In this paper, we propose a fault detection method with sensorless estimation using current ripples that estimates the position and velocity of the motor by detecting periodical oscillations of the armature current caused by rotor slots. In addition, this method can estimate the position and velocity of the motor with less computational effort than a state observer. Moreover, the method is less sensitive to motor parameters than model-based estimation methods. The effectiveness of this method is validated with experimental data, and the simulation results show that various faults have their own residual patterns. Therefore, we can detect the presence of faults by monitoring the residual signals.     

汽车零部件感应加热淬火设备知识讲座(五)恒反压时间逆变控制晶闸管(SCR)中频电源

1电源组成一汽集团公司零部件加热淬火应用最多的是恒反压时间逆变控制晶闸管(SCR)中频电源。单逆变桥中频电源基本结构见图1。     

沥青玛蹄脂碎石混合料(SMA)施工的试验测

从沥青玛蹄脂碎石混合料(SMA)的组料特点,介绍其与普通沥青混和料的区别,以及原材料检测指标和配合比的配置特点,并汇总了摊铺过程中的试验检测手段和指标,以西北地区施工案例介绍寒区SMA施工中的体会。     

日本制定未来汽车发展计划(下)

汽车交通安全 1999年日本交通事故死亡人数为9005人(事故发生后24小时内的死亡人数),这个数字在过去几年呈下降趋势。另一方面,交通事故数量(850363)和伤亡人数(1050398)却创造历史最高水甲。尽管在第六个交通安全基本计划期间交通事故死亡人数正在稳步降低,但是由于汽车总量日益增加和驾驶人员日趋老化,要实现在基本计划中日本政府所设定的交通事故总量、伤亡数量的控制目标绝不是一件轻而易举     

摩托车液压减振器(3)

(上接2003年第4期) 压缩永久变形:不大于自由高度H0的0.3%;垂直度偏差:不大于0.02H0～0.05H0;     

谈摩托车电起动系统（1）

1电起动电路 摩托车电起动系的作用是用蓄电池放出的电能驱动起动电机,起动电机带动发动机进入自动运转状态,它主要包括一个12 V的蓄电池,一个起动继电器,一台起动电机和一个点火开关,如图1所示.     

谈摩托车电起动系统(2)

(上接2001年第6期) 大中型摩托车常采用双继电器起动电路,在起动继电器电路中增加了一个断路继电器.用起动继电器接通起动机主电路,用断路继电器接通起动继电器电磁线圈电路.采用制动开关、空档开关、离合器开关、侧支架开关和起动按钮等多开关控制起动继电器电磁电路或断路继电器电磁电路的通断.以下列举了几种双继电器起动电路.     

摩托车液压减振器(2)

(上接2003年第3期) h)阻尼器正常阻尼区Hy+Hf,如图2、图3所示,活塞以静平衡位置为中心,以(S+△)/2为振幅的压缩和复原轴向振动范围.     

部分常用维修配件价目表(一)

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轿车柴油机(续完)

概述了轿车柴油机的发展历史和技术现状 ,介绍了国外典型产品的特点和技术参数以及轿车柴油机在国外的市场销售状况 ,预测了轿车柴油机的发展趋势 ,提出了我国发展轿车柴油机的策略建议。     

轿车柴油机(续)

概述了轿车柴油机的发展历史和技术现状 ,介绍了国外典型产品的特点和技术参数以及轿车柴油机在国外的市场销售状况 ,预测了轿车柴油机的发展趋势 ,提出了我国发展轿车柴油机的策略建议。     

摩托车液压减振器(1)

减振器是连接车身与车轮的一种弹性悬架.行业上习惯把阻尼器与悬架弹簧组装一起的叫"减震器";把独立的阻尼器叫"减振器".本文按<摩托车技术>统一要求叫"减振器".     

我国现行汽车强制性标准(二)

中国是世界上典型的以混合交通为主的国家,汽车对行人产生的交通伤害远远大于其他国家.我国现在正在制订的该标准是基于行人保护全球技术法规(GTR)而制定,与国际同步.     

摩托车节油实用技术（7）

(上接2001年第3期) 3.9制动器的调整 制动器的调整,既要确保摩托车能迅速可靠地制动,又要确保在放松制动时,制动器能迅速彻底回位,车轮无拖滞现象.因此,无论是盘式,还是鼓式制动器,均要定期调整块盘(或蹄鼓)之间的间隙至规定要求,间隙过大、过小均是不合适的.间隙过大,需提前制动,增加制动力,延长制动时间,不但使制动距离增加,而且油耗也会增加;间隙过小,要多耗部分燃料,克服摩擦阻力,使油耗增加,更为严重的是在不需制动时,由于间隙太小,有可能产生局部摩擦,亦即拖滞现象,增大行驶阻力,使油耗迅速升高.     

公路养护工程机械配备标准(7)

1总则 1.1目的 改革开放以来,中国公路建设进入了一个史无前例的高速发展阶段,尤其是高速公路的建设速度更是令人震惊,使中国公路通车总里程迅速增加.经过10多年运营,已建公路逐渐进入大、中修养护期,养护工程量将越来越大.同时,已建公路在运营过程中的合理养护不仅是提高运营服务水平的一个重要方面,而更重要的是及时修复道路病害,保证道路完好,提高道路通行能力,延长道路使用寿命,充分发挥公路运输经济、快捷、方便、安全的优势,提高道路的综合社会效益.因此,公路养护与公路建设具有同等重要的意义,而且是一项必须长期坚持做好的工作.     

摩托车节油实用技术（4）

(上接2000年第12期) c)车身结构的选择:车身的主要部件是车架,车架是支撑发动机,连接传动系、操纵系、车轮与悬架装置的极为关键的受力构件,通常在许可的强度范围内,尽可能轻量化及高刚性.目前,国产车一般采用钢管焊接结构,虽然强度与刚度足够,但质量太大,严重影响整车质量的减低.而摩托车行驶时的滚动阻力、爬坡阻力、加速阻力以及轴承的摩擦阻力等均与整车总质量成正比,油耗也会成正比增加,所以摩托车的轻量化日益为人们所重视.目前,国产车的车架、摇架、前叉、车轮、发动机等都在广泛应用轻质高强的镁铝合金;外覆件都在广泛使用各种塑料、纤维增强复合材料及玻璃钢等轻质材料,从而大大减小了车身及整车的质量,使摩托车加速性好、轻巧、省油.选购摩托车时,应对同排量、同型号的摩托车进行质量比较,尽可能选购那些广泛应用新材料、新技术的轻量化摩托车.     

捷达轿车空调控制单元（续完）

5 506A型空调控制单元J293 零件号为357919506A的空调控制单元J293有30、1、2这3个大插脚和P、31、T2、T4、X、MK、T1和T这8个小插脚,比506、506B、506C等多了T、T1这2个小插脚。内部采用双面敷铜板固定着电风扇高速继电器J1、电风扇低速继电器J2和压缩机离合器继电器J3,每个继电器都由一个晶体管开关电路来控制它的线圈通路。此外还有一个集成块和几十个电子元件。