With the rapid development of the auto industry, applications of sensors used on automobiles are becoming larger and larger. Now they have been used in ares such as auto electronic control systems, lane departure warning systems and blind-spot detection systems and so on. For the demands for comfort, environmental friendliness and entertainment has been raised, it is predicted that the sensor market will rise from 8 billion dollars in 2007 to 13.5 billion dollars, with compound annual rate of growth of 10.8 percent.
At present, there is a steady demand for auto sensors. The auto sensor is a input device for computer system, it can transfer information such as the speed, temperatures of various medium and engine conditions to electronic signals which can be transmitted to computers. As a result, the engine will work under the best condition. One of the characters of modern automobile is that more and more parts are electronic controlled. According to its usage, sensors can be classified into many kinds and play the roles respectively. Ones one of them failed, the entire function of a vehicle will be badly influenced and can not work well. So sensors are the important parts of a vehicle.
As the information source for electronic control system, auto sensors are the key parts of the system. Now, for an average family car, hundreds of sensors are set to be used in engine control system, under pan control system and navigation system. Developed countries such as America, have already had a complete system. With the fast development of electronic technology and the wide application of electric control system, sensors which are more intelligent, multifunctional and integrated ar