雷达技术应用于交通安全问题

Radar is a kind of radio technology, which uses the secondary radiation, transmission or inherent radiation of electromagnetic wave to detect the target and obtain the spatial coordinates, velocity and characteristics of the target. Maybe many people think that this technology is widely used in the military field and can not play a very important role in dealing with social problems. In fact, with the progress of society, radar technology is more and more widely used in various fields of society.
After the Industrial Revolution, automobiles have come into people’s vision as a new generation of vehicles. However, while high-speed brings convenience to people, it also brings the hidden danger of frequent accidents. The application of radar system improves the original security level, reduces the fault in the driving period, and carefully ensures the safety. Some people may ask that ultrasound and laser technology can also play a role in detecting the environment. Why is radar technology unique? Compared with the above two, the radar can adapt to the changing environment, and can operate normally under the conditions of pollution or bad weather. Its anti-jamming characteristics also enable the technology to have high accuracy in the calculation of the preset detection distance, the measured speed and the planned driving route. Additionally, the small size of its accessories makes it suitable for layout on all kinds of bodywork.
Everyone knows that one of the most important reasons for traffic accidents is that the braking distance is larger than the vehicle distance because of the long reaction time of drivers. The early warning function of automobile radar system greatly reduces the possibility of collision. ACC system is an automobile ranging radar system with millimeter wave radar as its main research direction. Millimeter wave refers to the short-wavelength electromagnetic wave whose wavelength is between 1-10 mm. The target position is detected and determined by the reflection of the target to the electromagnetic wave. There are mainly dual-frequency CW radar, spread spectrum radar and FM electromagnetic wave radar, among which FM electromagnetic wave radar has become a popular target for consumers because of its low price and stable performance.
When the FMCW rader works, the intermediate processing signal output by mixing enters the mixing part and filters out the interference signal. By comparing the reflected signal with the transmitted signal, the frequency difference proportional to the measured distance is obtained. The relative velocity of the target can also be determined by the Doppler shift of the return signal. When the speed of the accessory vehicle is predicted in advance, the driver can make gearshift preparation in advance, and the probability of accidents will naturally be reduced. Moreover, FMCW radar equipped with multi-beam antennas can establish characteristic curves when receiving different intensity radio signals, continuously and independently measure the relative velocity and azimuth angle of the target vehicle, and continuously filter out the updated position data of the target to achieve continuous tracking of the target vehicle. The high sensitivity of the system makes the analysis data more stable, and also makes it rank first in many vehicle assistance systems in the ability to distinguish lanes and corners.
During 1960s and 1970s, European and American countries began to study millimeter wave radar. Since the reform and opening up, our country has been studying the technology of developed countries carefully while taking the essence to remove the dregs. We have made a thorough study on the absorption, application and post-processing data of the advanced western vehicle-borne radar, and created the first millimeter-wave monolithic integrated circuit FMCW vehicle anti-collision system in Shanghai Academy of Chinese Sciences. Since then, Tsinghua University, Jilin University and other well-known universities have invested in research, and achieved good results. It is precisely the introduction and excavation of advanced technology by our predecessors that has greatly improved the safety factor of our transportation system.
Nevertheless, there is never a perfect thing in the world. If we do not follow the trend of the times to achieve their own renewal, it will be replaced by endless new products. Nowadays, people depend more and more on intelligent electronic products. The electromagnetic interference produced by intelligent electronic products can easily lead to misjudgement of radar system. Therefore, in order to ensure driver safety ， it is necessary to improve the anti-jamming system, introduce information fusion technology and make radar and sensor complement each other into a sensor network, so as to have a complete sense of the external environment and improve the correctness of decision-making. Secondly, there is a big gap between rich and poor in China, and the cost of using DSP technology to process radar system is very high. I believe that the rapid development of micro-refining technology and microwave module manufacturing technology should be used to improve the detection accuracy while achieving low-cost equipment installation. Lastly, long-term exposure to electromagnetic radiation may endanger driver’s health. While researching the detection accuracy, if researchers can discover the frequency band that can be maximally blocked by the atmosphere, there is no doubt that the application of radar technology in the field of traffic safety will benefit mankind for a long time.
Traffic accidents are one of the greatest threats to human life nowadays. They cause high property losses，take people’s lives, break families and separate flesh and blood. Vehicle radar saves countless lives through advanced functions such as ranging, shooting, alarm and so on. In my opinion, the traveling radar system symbolizes the trend of modern technology and ensures the usual traffic safety.