自动控制文献翻译——尽管铁路作为一种交通工具，有着良好的安全记录。但司机使列车通过那些本应该停车点的位置时，就会有以外发生。这些事故大多数会导致碰撞，其中一些可能会丧失生命，造成设备或财产的毁坏。大多数事故是由于火车司机没能确保列车在停车信号点停车。在英国，这就是所众所周知的SPAD系统简称危险点的允许通过信号。

从19世纪人们开始着手解决此问题，并引进过各种系统试图来阻止此类事故发生，这种事故就一直发生着。这些系统采用了报警和列车制动两种形式。在英国，报警系统用在了很多主干铁路线上。当列车靠近一个警示点或是停车信号点时，驾驶室内的报警器就会鸣响。如果司机没有意识到报警，列车制动系统就会启用。这个系统被称为AWS即自动报警系统。

自动报警系统（AWS）

甚至在WW1系统之前，人们就意识到需要某种自动而且强制性的报警措施。经过大量的实验和一些完整系统的测试以后，报警系统采用了“小山型”非接触（自动报警系统）的形式，这个自动报警系统的“斜坡”作为感应器是很知名的，这个“斜坡”被设置在接近信号侧距信号点185米处。

报警装置的“斜坡”设置在铁路线路中间，以便列车上的检测器能越过并且能接收到信号。这个“斜坡”能给司机提供信号状态的警示。法国铁路运用了一个类似的系统称为“the Crocodile”，德国叫“Induis”。

此报警“斜坡”包含一对磁铁，第一个是永久性磁铁，第二个是电磁铁，他们连接在信号机上，提供坡度的信息表示。“斜坡”设在线路中间的目的是装在列车上的检测器能接收到表示器的数据信息。很多在站台上的检测人员可以在铁路中间看到“斜坡”。这些“斜坡”的颜色是灰黄色的。

在运行的过程中，首先，列车越过永久性磁铁，列车上的接收器为使用制动设备而设置了一个触发器。接着，列车通过永久性磁铁。如果信号为绿灯，电磁铁获得能量。制动触发器不动作，在驾驶室内的触发条.......

In spite of the excellent safety record of railways as a means of transportation, there have been occasions when drivers have allowed their train to pass a point where they should have stopped. Many of these incidents have resulted in collisions, some involving loss of life and most involving damage to equipment or property. Most incidents are the result of a driver failing to ensure that his train stops at a stop signal. In the UK, this has become known as SPAD or Signal Passed At Danger. 

Such incidents have occurred on railways ever since they began in the early 19th century and various systems have been introduced to try to prevent them. These have taken the form of both warning and train stop systems. In the UK, a warning system is used on most main lines. An alarm sounds in the driver's cab whenever a train approaches a caution or stop signal. If the driver fails to acknowledge the alarm, the train brakes are applied. The system is called AWS (Automatic Warning System)

It was realised (even before WW1) that some sort of automatic and enforceable warning was needed. This (after a number of experiments and some complete systems had been tried) eventually took the form of a track mounted, non-contact inductor which became known as AWS (Automatic Warning System). The AWS "ramp" as the inductor is known, is placed about 185 metres (200 yards) on the approach side of the signal (diagram, left). 

The AWS ramp is placed between the rails so that a detector on the train will pass over it and receive a signal. The ramp will thus warn the driver of the status of the signal. The French railways use a similar system called "the Crocodile", the Germans, the "Indusi".

The AWS ramp contains a pair of magnets, the first permanent, the second an electro-magnet linked to the signal to provide an indication of the aspect. The ramp is placed between the rails so that a detector on the train can receive the indication data. The more observant passenger on a station platform can often see the ramps between the rails. They are usually a ......