Automobile Brake System
The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.
Two complete independent braking systems are used on the car. They are the service brake and the parking brake.
The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.
The brake system is composed of the following basic c omponents: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.
The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).
Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.
In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.
At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.
The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.
The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the
best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.
Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.
Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the
sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.
The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid
pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.
The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.
Anti-lock Brake System
Anti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.
Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.
Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.
In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.
The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡ system consists of : four wheel speed sensor, electronic control unit and modulator assembly.
A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a
winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced inthe winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.
The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.
Modulator assembly
The hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three
high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.
Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store
fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.
汽车制动系统
制动系统是汽车上最重要的系统。如果制动系统坏了，结果会很严重。制动器实际上是能量转化装置，制动器能将车辆的动能（动量）转化为热能（热）。当司机踩制动踏板时，司机施加的使汽车停下的力相当于推动汽车的力的十倍。制动系统能施加在每个制动器上的力有几千磅。
汽车上装有两套完全独立的制动系统，即行车制动系统和驻车制动系统行车制动用来减速、停车或者控制正在正常行驶的车辆，它是通过司机踩下和释放刹车踏板来控制的。驻车制动的主要目的是使车辆在无人看管时保持静止状态。驻车制动是机械式操作，司机可以通过一个独立的驻车制动刹车脚踏板或者刹车手柄来操控。
制动系统由下列基本部分组成：“制动主缸”，安装在发动机罩的下面，直接与制动踏板相连，将司机脚部的机械压力转化为液压压力。钢制的“制动管路”和柔韧的“制动软管”将制动主缸与安装在各个车轮上的“制动轮缸”连接起来。制动液，特别设计工作在极端环境下，充满制动系统。“制动蹄”和“制动衬块”在制动轮缸的推动下分别与“制动鼓”和“制动盘”接触而产生阻力，从而（有希望）使汽车减速。
典型的制动系统由前部的盘式制动器和后部的盘式或鼓式制动器组成，制动器用管道与制动主缸相连。
基本上，所有的汽车制动器都是摩擦式制动器。当司机开始制动时，控制装置迫使制动蹄或者制动衬块挤压车轮上的旋转的制动鼓或者制动盘。制动蹄与制动鼓或者制动衬块与制动盘之间的摩擦使车轮减速或者停下，从而使汽车被刹住。
大多数现代制动系统里都有一个充满液体的缸体，叫做制动主缸，它包含两个独立的部分，每个部分都有一个活塞，每个活塞都和司机驾驶室的刹车踏板相连。当踩下制动踏板时，制动液就被从制动主缸压到各个车轮。
在各个车轮处，制动液推动制动蹄或制动衬块与旋转的制动鼓或制动盘接触。静止的制动蹄或制动衬块与转动的制动鼓或制动盘之间的摩擦，使制
动鼓或制动盘减速或停止，这将使车轮减速或者停止，进而使汽车减速或者停止。
制动液储液罐在制动主缸的顶部。今天大部分的汽车的制动液储液罐都是透明的，以便你不必打开盖子就能看到液面的高度。制动液的液面会随着制动衬块的摩擦而下降，这是正常状况不必担心。如果液面高度在短时间内明显下降或者下降了三分之二，请尽快检查你的制动系统。保持制动液储液罐的盖子是关闭状态，除非你需要加油，绝不要让凸轮制动液暴漏着。制动液必须保持非常高的沸点，暴漏在空气中将造成制动液吸收水分而沸点降低。
制动液通过一系列钢制管路和强化的橡胶管从制动主缸到达车轮处。橡胶管路仅仅用在对柔韧性有要求的地方，如前轮处，管路会随着形式上下移动。剩下的系统管路用不锈无缝钢管通过特殊配件相连。如果钢制管路需要修理，最好的方式是更换相同的管路，如果这不实际，也可以用为制动系统维修专门生产的专用接头配件来修理。决不能用铜制管路来维修制动系统，那样很危险而且违反规定。
鼓式制动器，包括制动鼓、一个制动轮缸、回位弹簧、一个制动底板、两个带摩擦片的制动蹄和支承销。制动底板固定在驱动桥壳的法兰盘上或者转向节上。制动鼓安装在轮毂上。制动鼓的内表面与制动蹄摩擦片之间有一段间距。制动时，司机踩下踏板，制动轮缸是制动蹄张开压在制动鼓上。制动鼓与摩擦片之间的摩擦使车轮制动，使车辆停止。解除制动时，司机放开踏板，回位弹簧拉回制动蹄从而使车轮能自由转动。
盘式制动器，有一个金属盘代替了制动鼓。制动盘两侧各装有一个平的制动蹄或者叫盘式制动摩擦衬块。制动衬块挤压旋转的制动盘使汽车停止。来自制动主缸的制动液迫使轮缸的活塞向制动盘移动，从而推动摩擦衬块紧紧地压在制动盘上。摩擦衬块与制动盘之间的摩擦使制动盘减速和停止，这就是制动的过程。活塞是塑料或者金属制的。盘式制动器有三种基本类型，浮钳盘式制动器、定钳盘式制动器和滑动钳盘式制动器。浮钳盘式制动器和滑动钳盘式制动器用一个活塞，定钳盘式制动器有两个或者四个活塞。
制动系统装配组件驱动方式有机械式、液压式或者气压式。机械式杠杆机构适用于所有汽车的驻车制动。当踩下制动踏板时，推杆推动制动主缸的活塞移动，制动液从油管流到动力制动单元再流到制动轮缸，制动液的压力
推开轮缸的活塞，从而使摩擦片挤压制动鼓或制动盘。如果放开制动踏板，活塞回到初始位置，回位弹簧使制动蹄回位，制动液被压回主缸，制动停止。
驻车制动的主要作用是使车辆在无人看管时保持静止，驻车制动是机械式操作，司机通过一个独立的制动手柄来操纵。手刹通常在汽车已经停下时使用。当拉动手刹时，后制动系统被刹住并被锁在“打开”的位置，现在可以把汽车扔下而不用担心它自己移走了。当司机想要再次移动汽车时，他必须按一个按钮才能使手刹拉杆松开。手刹还必须能在脚刹失灵的情况下使汽车停止，因此，手刹系统采用拉索或杠杆，不同于脚刹采用液压系统。
防抱死制动系统使制动更加安全和方便，防抱死制动系统调节制动系统液压，防止制动器锁死，防止轮胎在光滑路面上或紧急制动时发生打滑。
防抱死制动系统已经用在航空飞行器上多年，90年代末期，一些国产汽车装备了早期形式的防抱死制动系统。现在，一些汽车制造商已经引进了更先进的防抱死制动系统。在防抱死制动系统已经应用十年的欧洲进行的一项调查说明，如果所有的车都有防抱死制动系统，交通事故的数量将可以减少7.5%，所以一些人预计将来所有的车都会装上防抱死制动系统，以提高汽车的安全性。
防抱死系统每秒调节制动作用力几次，以把轮胎的滑移量控制在一定范围内；基本上所有的系统都是以这种方式来完成的。一个或多个速度传感器产生交流信号，交流信号的频率随着车轮转速的提高而增大一个电控单元不断监测着这些信号，如果其中一个信号的频率下降的太迅速，表明一个车轮将要抱死，电控单元命令调节装置减小受影响车轮的制动液压。当传感器信号表明车轮仍在正常转动时，控制单元允许制动器增大液压，这种收放循环每秒发生几次，对制动器的控制类似于司机反复释放和踩下踏板，但是速度更快。
除了他们的基本作用，关于防抱死系统还有另外两件事。第一，防抱死系统直到制动器抱死车轮才起作用，在其他时间，防抱死系统做好运行的准备，但是不干涉正常制动。第二，如果防抱死系统失灵了，制动器没有了防抱死能力仍然能继续工作，当防抱死系统存在问题时，仪表盘上的一个警示灯会提示司机。
欧洲汽车制造商，如宝马、奔驰和保时捷，广泛使用的是博世的第二代
防抱死制动系统ABSⅡ。ABSⅡ系统包括：四个车轮转速传感器、电子控制单元和调节装置。
装在每个车轮上的轮速传感器将车轮转动信号送到控制单元，每个速度传感器包括一个磁感应传感头和一个齿圈。前轮传感器安装在转向节上，它的齿圈安在转向轴上，随车轮一起旋转。后传感器安装在后悬架部件上，它的齿圈安装在车轴上。传感器是一个有磁芯的线圈，磁芯产生一个环绕线圈的磁场，当齿圈的齿穿过磁场时，线圈中会产生交流电。控制单元监测着频率变化的速度，以判断什么时候即将抱死。
控制单元的作用可以分为三部分：信号处理，逻辑计算和安全电路。信号处理部分是将从轮速传感器接收到的交流信号转换成数字形式，为逻辑计算做准备。然后逻辑计算部分分析这些数字化的信号，计算出制动压力需要的改变。如果觉察到即将抱死，逻辑计算部分将向液压调节器发出命令。
当液压调节器接受到控制单元的命令时，将会调节车轮制动器中的液压。液压调节器能保持或者减少来自制动主缸的压力，但是它不能自己启动制动器。液压调节器包括三个高速的电磁阀、两个储液器和一个装有进出口止回阀的输出泵。调节器的电子连接器和控制继电器隐蔽在塑料盖子下。
每个前轮都有一个电磁阀，受控制单元独立调节。两个后轮则只有一个电磁阀，采用低选择原则共同调节。在防抱死制动系统起作用时，控制单元循环控制电磁阀保持或者减小制动系统的液压，当防抱死期间制动系统液压被降低时，制动液被压入储液器。前制动线路有一个储液罐。储液罐是低压蓄能器，在低压下储存油液，直到回流泵将油液从管路送回制动主缸。
外文出处： 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题： JDBC接口技术 译文： JDBC是一种可用于执行SQL语句的JavaAPI（ApplicationProgrammingInterface应用程序设计接口）。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口，使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC，很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢？如果有，那么它们之间又是怎样的关系呢？ ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统（DBMS）中存取数据的，用C语言实现的，标准应用程序数据接口。通过ODBCAPI，应用程序可以存取保存在多种不同数据库管理系统（DBMS）中的数据，而不论每个DBMS使用了何种数据存储格式和编程接口。 1．ODBC的结构模型 ODBC的结构包括四个主要部分：应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口：屏蔽不同的ODBC数据库驱动器之间函数调用的差别，为用户提供统一的SQL编程接口。 驱动器管理器：为应用程序装载数据库驱动器。 数据库驱动器：实现ODBC的函数调用，提供对特定数据源的SQL请求。如果需要，数据库驱动器将修改应用程序的请求，使得请求符合相关的DBMS所支持的文法。 数据源：由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器，以便ODBC函数调用，但是数据库驱动器本身也执行ODBC函数调用，并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时，数据库驱动器能管理通信协议。当建立起与数据源的连接时，数据库驱动器便能处理应用系统向DBMS发出的请求，对分析或发自数据源的设计进行必要的翻译，并将结果返回给应用系统。 2．JDBC的诞生 自从Java语言于1995年5月正式公布以来，Java风靡全球。出现大量的用java语言编写的程序，其中也包括数据库应用程序。由于没有一个Java语言的API，编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥，比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱，越来越多的公司在Java程序开发上投入的精力日益增加，对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处，比如它并不容易使用，没有面向对象的特性等等，SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1．x 版本中，JDBC只是一个可选部件，到了JDK1．1公布时，SQL类包（也就是JDBCAPI）
On the vehicle sideslip angle estimation through neural networks: Numerical and experimental results. S. Melzi,E. Sabbioni Mechanical Systems and Signal Processing 25 (2011)：14~28 电脑估计车辆侧滑角的数值和实验结果 S.梅尔兹,E.赛博毕宁 机械系统和信号处理2011年第25期：14~28
摘要 将稳定控制系统应用于差动制动内/外轮胎是现在对客车车辆的标准（电子稳定系统ESP、直接偏航力矩控制DYC）。这些系统假设将两个偏航率(通常是衡量板)和侧滑角作为控制变量。不幸的是后者的具体数值只有通过非常昂贵却不适合用于普通车辆的设备才可以实现直接被测量,因此只能估计其数值。几个州的观察家最终将适应参数的参考车辆模型作为开发的目的。然而侧滑角的估计还是一个悬而未决的问题。为了避免有关参考模型参数识别/适应的问题,本文提出了分层神经网络方法估算侧滑角。横向加速度、偏航角速率、速度和引导角,都可以作为普通传感器的输入值。人脑中的神经网络的设计和定义的策略构成训练集通过数值模拟与七分布式光纤传感器的车辆模型都已经获得了。在各种路面上神经网络性能和稳定已经通过处理实验数据获得和相应的车辆和提到几个处理演习(一步引导、电源、双车道变化等)得以证实。结果通常显示估计和测量的侧滑角之间有良好的一致性。 1 介绍 稳定控制系统可以防止车辆的旋转和漂移。实际上，在轮胎和道路之间的物理极限的附着力下驾驶汽车是一个极其困难的任务。通常大部分司机不能处理这种情况和失去控制的车辆。最近,为了提高车辆安全，稳定控制系统(ESP[1,2]; DYC[3,4])介绍了通过将差动制动/驱动扭矩应用到内/外轮胎来试图控制偏航力矩的方法。 横摆力矩控制系统（DYC）是基于偏航角速率反馈进行控制的。在这种情况下,控制系统使车辆处于由司机转向输入和车辆速度控制的期望的偏航率[3,4]。然而为了确保稳定，防止特别是在低摩擦路面上的车辆侧滑角变得太大是必要的[1,2]。事实上由于非线性回旋力和轮胎滑移角之间的关系，转向角的变化几乎不改变偏航力矩。因此两个偏航率和侧滑角的实现需要一个有效的稳定控制系统[1,2]。不幸的是,能直接测量的侧滑角只能用特殊设备(光学传感器或GPS惯性传感器的组合)，现在这种设备非常昂贵,不适合在普通汽车上实现。因此, 必须在实时测量的基础上进行侧滑角估计，具体是测量横向/纵向加速度、角速度、引导角度和车轮角速度来估计车辆速度。 在主要是基于状态观测器/卡尔曼滤波器(5、6)的文学资料里, 提出了几个侧滑角估计策略。因为国家观察员都基于一个参考车辆模型,他们只有准确已知模型参数的情况下，才可以提供一个令人满意的估计。根据这种观点,轮胎特性尤其关键取决于附着条件、温度、磨损等特点。 轮胎转弯刚度的提出就是为了克服这些困难,适应观察员能够提供一个同步估计的侧滑角和附着条件[7,8]。这种方法的弊端是一个更复杂的布局的估计量导致需要很高的计算工作量。 另一种方法可由代表神经网络由于其承受能力模型非线性系统，这样不需要一个参
附录 附录A Braking system function is to make the car driving in accordance with the requirements of the pilot required even slow down park; They offend car has in various road conditions (including in the slope stability) in car; Make the downhill cars speed to be stable. For car up the role of brake is only in the car and role with the direction of the car driving direction opposite forces, and the size of these forces are random, do not control, so cars must be installed on a series of special equipment to achieve the function. Automobile brake system is to point to to ensure that the car in technology, improve the safe driving car average speed, etc., and the admiration installed in the car brake special brake institutions. In general automobile brake system including crane brake system and parking brake two sets of independent device. One crane brake device is a driver with feet to manipulate, and it said the foot brake. Parking brake device is a pilot with the hand, so it says of the manipulation of the hand brake. The function of the crane brake system is to make the car slow down or running in the shortest distance parking within. And parking brake function is to make had stopped the car on the road all keep still. But, sometimes, in an emergency, two braking device can be used at the same time and increase the effect of auto brake. Some special purpose of cars and often in the mountains cars, long and frequently brake will lead to crane brake system overheating, so in these cars often add all sorts of different types of auxiliary braking equipment, so as to speed up the hill stability. According to the braking energy situation, brake system can also be divided into human brake system, power brake system, and servo brake system, three. Human brake system to the driver's physical strength as braking energy; Power brake system engine power to the transformation of the air pressure or hydraulic braking energy as; And servo brake system is the most human and engine power as a brake energy. In addition, according to the braking energy transfer mode, brake system and can be divided into mechanical and hydraulic, pneumatic type and assolenoid style wait until a few kinds.
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
本科生毕业论文（设计）题目文献综述文献综述随着改革开放的深入，交通运输在生活中的作用越来越明显，高速公路的建设成为了国民建设中的一个重大问题。由于高速公路具有汽车专用，分隔行驶，全部立交，控制出入以及高标准，高要求，设备功能完善等功能，与一般公路相比具有很多优点，所以具有很强的实用性。目前，我国高等级公路建设正处在“质”与“量”并重的重要发展阶段。从大陆第一条高速公路——沪嘉高速开始，中国大陆高速公路建设进入了一个崭新的时期。高速公路在二十多年间展现出了巨大的优越性，在以建成的高速公路沿线及腹地迅速兴起了工业企业建设的热【1】潮，地价增值，地方税收增加，投资环境发生巨大变化。目前我国的高速公路主要分布在东南沿海，我国的沿海地带，大部分是淤泥质海岸。因此，沿海特别是大江大河河口附近多为河相、海相或泻湖相沉积层，在地质上属于第四纪全新纪Q4 土层，多属于【2】东南海岸土的类别多为淤泥，淤泥质亚黏饱和的正常压密黏土。土。这类地基的主要特点是：具有高含水量、大孔隙、低密度、低强度、高压缩性、低透水性、中等灵敏度等特点；具有一定的结构性。由于这类地基存在这些特点，在软粘土地基上建造建筑物普遍存在稳定及变形的问题。以高速为例，由于高速的路堤高度不大，所以稳定问题并不突出，但是变形问题很明显。目前高速桥头跳车以及高填方段、填挖结合部等位置因地基差异沉降对路面结构造成的不良影响已引起公路建设、设计、监理、施工等部门的日益重视。如何解决高等级公路桥头跳车问题已成为刻不容缓的大事。造成桥头跳车的原因【3】有很多：1、土质不良引起的地基沉陷：土质不良，由此产生沉陷是桥头跳车的主要原因。桥涵通常位于沟壑地方，地下水位较高，此类土天然含水量大于液限，天然孔隙比大，常含有机质，压缩性高，抗剪强度低，一旦受到扰动，天然结构易受破坏，强度便显著降低，桥头路基填筑高度较大，产生基底应力相对较大，在车辆荷载作用下，更容易引起地基沉陷，且变形稳定历时往往持续数年乃至更长的时间。既便是在一些稳定地基，在外荷作用下，也无可避免出现这个问题。2、台后填料的压缩沉降：台后填料一
Automobile Brake System The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes. Two complete independent braking systems are used on the car. They are the service brake and the parking brake. The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set. The brake system is composed of the following basic c omponents: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car. The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).
附录 Modern car’s design always stresses people-oriented, so safety, comfort, Environmental protection and energy saving have been the design theme And target in car design. Ergonomics layout design is not only relate to the effective use of internal space and improve car’s comfort and safety Performance, but it will also impact internal and external modeling results, and further affects the vehicle's overall performance and marketability.Soergonomics’application and research during car design and development process occupy an important position.After more than 50 years of construction and development, China’s Automobile industry has become the leading power of automobile production and consumption in the world. In particular, with the rise and rapid de velopment of independent brand’s vehicles, we pay more attention To the development processes and the technical requirements of hard Points’ layout. Through the three typical processes such as modern vehicle developing Process, body development process and using ergonomic to progress Inner auto-body layout, describe ergonomic layoationship between design, Aunt design in which stage of the process of vehicle development, the red The importance of working steps. The automobile body total arrangement is the automobile design most initial is also the most essential step, is other design stage premise and the foundation, to a great extent is deciding the body design success or failure. Picks generally in the actual design process With by forward and reverse two design method (1) to design (from inside to outside law) to design method namely "humanist", is coming based on the human body arrangement tool to define the pilot and the crew member gradually rides the space and the vehicle comes to pay tribute each article the arrangement, take satisfies the human body to ride with the driving comfortableness as the premise, said simply is determined first satisfies the human body to ride under the comfortable premise, carries on the indoor arrangement first, then carries on the complete bikes external styling design again. The concrete method and the step are as follows: ①Determine 5% and 95% manikin H position and the chair by the SAE recommendation's enjoyable line or the region law adjustment traveling schedule, seat
I / 11 本科毕业设计外文翻译 <2018届） 论文题目基于WEB 的J2EE 的信息系统的方法研究 作者姓名[单击此处输入姓名] 指导教师[单击此处输入姓名] 学科(专业 > 所在学院计算机科学与技术学院 提交日期[时间 ]
基于WEB的J2EE的信息系统的方法研究 摘要：本文介绍基于工程的Java开发框架背后的概念，并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复，而且并不总是符合最佳实践，所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式，代表有效解决办法的工具。开发框架提供：<1）从用户界面到数据集成的应用程序开发堆栈；<2）一个架构，基本环境及他们的相关技术，这些技术用来使用其他一些框架。架构定义了一个开发方法，其目的是协助客户开发工程。 关键词：J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台，以实现他们的用户界面，科学分析，分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此，WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平，使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下，开源框架没有提供常见问题的一个解决方案。出于这个原因，开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架，该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架，本文提出了新的架构，基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法，其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求，也
毕业设计（论文） 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年
研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院，中国南京，邮编210098 nzg_197901@https://www.doczj.com/doc/c613251543.html,，niuzhiguo@https://www.doczj.com/doc/c613251543.html, 李同春 河海大学水利水电工程学院，中国南京，邮编210098 ltchhu@https://www.doczj.com/doc/c613251543.html, 摘要 由于钢弧形闸门的结构特征和弹力，调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中，简化空间框架作为分析模型，根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型，动态不稳定区域的弧形闸门可以通过有限元的方法，应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外，结合物理和数值模型，对识别新方法的参数共振钢弧形闸门提出了调查，本文不仅是重要的改进弧形闸门的参数振动的计算方法，但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力，没有门槽，好流型，和操作方便等优点，使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门，通过门叶和主大梁，所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂，手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中，除了极特殊的破坏情况下，弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外，明显的动态作用下发生破坏。例如:张山闸，位于中国的江苏省，包括36个弧形闸门。当一个弧形闸门打开放水时，门被破坏了，而其他弧形闸门则关闭，受到静态静水压力仍然是一样的，很明显，一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。
The development of automobile As the world energy crisis and the war and the energy consumption of oil -- and are full of energy in one day someday it will disappear without a trace. Oil is not inresources. So in oil consumption must be clean before finding a replacement. With the development of science and technology the progress of the society people invented the electric car. Electric cars will become the most ideal of transportation. In the development of world each aspect is fruitful especially with the automobile electronic technology and computer and rapid development of the information age. The electronic control technology in the car on a wide range of applications the application of the electronic device cars and electronic technology not only to improve and enhance the quality and the traditional automobile electrical performance but also improve the automobile fuel economy performance reliability and emission spurification. Widely used in automobile electronic products not only reduces the cost and reduce the complexity of the maintenance. From the fuel injection engine ignition devices air control and emission control and fault diagnosis to the body auxiliary devices are generally used in electronic control technology auto development mainly electromechanical integration. Widely used in automotive electronic control ignition system mainly electronic control fuel injection system electronic control ignition system electronic control automatic transmission electronic control ABS/ASR control system electronic control suspension system electronic control power steering system vehicle dynamic control system the airbag systems active belt system electronic control system and the automatic air-conditioning and GPS navigation system etc. With the system response the use function of quick car high reliability guarantees of engine power and reduce fuel consumption and emission regulations meet standards. The car is essential to modern traffic tools. And electric cars bring us infinite joy will give us the physical and mental relaxation. Take for example automatic transmission in road can not on the clutch can achieve automatic shift and engine flameout not so effective improve the driving convenience lighten the fatigue strength. Automatic transmission consists mainly of hydraulic torque converter gear transmission pump hydraulic control system electronic control system and oil cooling system etc. The electronic control of suspension is mainly used to cushion the impact of the body and the road to reduce vibration that car getting smooth-going and stability. When the vehicle in the car when the road uneven road can according to automatically adjust the height. When the car ratio of height low set to gas or oil cylinder filling or oil. If is opposite gas or diarrhea. To ensure and improve the level of driving cars driving stability. Variable force power steering system can significantly change the driver for the work efficiency and the state so widely used in electric cars. VDC to vehicle performance has important function it can according to the need of active braking to change the wheels of the car car motions of state and optimum control performance and increased automobile adhesion controlling and stability. Besides these appear beyond 4WS 4WD electric cars can greatly improve the performance of the value and ascending simultaneously. ABS braking distance is reduced and can keep turning skills effectively improve the stability of the directions simultaneously reduce tyre wear. The airbag appear in large programs protected the driver and passengers safety and greatly reduce automobile in collision of drivers and passengers in the buffer to protect the safety of life. Intelligent electronic technology in the bus to promote safe driving and that the other functions. The realization of automatic driving through various sensors. Except some smart cars equipped with multiple outside sensors can fully perception of information and traffic facilities