Welcome to the radar auxiliary driving the world.

You late at night is still on the road gallop, hurry hurry, your electronic records almost fill your truck is seriously overloaded. The rain was increasing. You think too fast, but the car around, but he is not slow.

Suddenly, an alarm to let your spirit. Your instinct of the front headlights to observe - to see anything clearly. But your car has begun an emergency brake. You write on a dashboard display there, a red image is an overturned truck blocked the lane around the bend. Your truck stop, the headlights lit up is trying to rescue workers rescued truck drivers.

In the next few years, the radar will play an important role in the development of advanced driver assistance systems (ADAS). With the expansion of its role, the radar transceiver, signal processing and automatic hedging function will allow the vehicle ADAS system more and more like a tactical combat aircraft systems, automotive systems will be the basis of a large impact.

Much of the discussion on the ADAS are concentrated in a passive vision system using visible wavelength camera. Freescale Semiconductor, the company's radar system the engineers RalfReuter very convincing 77-GHz radar. Reuter in talking about a recent interview: "The important point is, of ADAS sensing radar is nothing to do with the weather. Cameras identify the target on the advantages of radar are better at detecting objects, to measure its speed." Reuter explains, For these reasons, many of the early emphasis on detection and risk classification assessment system will choose the radar. He said: "In Europe, the emergency braking system of the truck there is great demand. It is based on radar."

The radar system will start a car dvd player and in car dvd player simple mid-range systems, forward look into the entire road. However, soon developed into the multi-sensor system, including long-distance forward-looking and short-range 360-degree risk assessment function, shown in Figure 1.

Although the optical visual system is very mature, and the advantages of radar systems to make it more perfect. Reuter predicted that in the near future, the target recognition of the complexity of the multi-camera system can integrate video and radar data, a dynamic model of the world around.

Understand the impact of radar on the vehicle system design is started from the understanding of sensor. Most of the automotive radar design are willing to use 24 - or 77-GHz free band. The transmitter is usually frequency modulated continuous wave (FMCW) design, it issued a "chirp": rapid changes in the frequency domain, shown in Figure 2.

Reuter explained that: "The biggest advantage of an FMCW is to simplify the understanding of the reflected signal. You can read directly from the reflection frequency of the target range from the Doppler frequency shift derived from the speed pulse modulation scheme, to produce CW not too complex, is also very easy to understand, very reliable vehicle manufacturers are most concerned about, they feel to each on the ADAS one euro spent on improvements come directly from corporate profits.