Time:2024-03-24
In recent years, autonomous driving has become the hottest topic today. With the development of autonomous driving technology, millimeter wave radar, as one of its key sensors, has also received widespread attention. Overseas giants have always dominated the development of the global millimeter wave radar industry, while domestic enterprises have long been in a shortage of talent and unable to break through technological barriers. However, in recent years, some domestic companies represented by SenseTime, Anzhijie, Chengtai, Mozhibi, Huayu, OCULII, Anzhi, and Furuidek have begun to explore millimeter wave radar technology and have achieved great results.
What is millimeter wave radar?
Millimeter wave radar is a radar that operates in the millimeter wave frequency band. Millimeter waves usually refer to electromagnetic waves in the frequency domain of 30-300GHz (wavelength of 1-10mm). Millimeter waves are located in the wavelength range where microwave and far-infrared waves overlap, so millimeter waves have both the advantages of these two spectra and their own unique properties. Compared with microwaves, millimeter waves have high resolution, good directionality, strong anti-interference ability, and good detection performance. Compared with infrared, millimeter waves have less atmospheric attenuation, better penetration through smoke and dust, and are less affected by weather. In addition, millimeter wave radar exhibits superior performance in measuring the distance, speed, and angle of targets compared to other sensors such as LiDAR and cameras.
The unique advantages of millimeter wave radar make it the main sensor for advanced driver assistance systems (ADAS) in automobiles, and an important guarantee for stable operation of autonomous driving. In fact, millimeter wave radar can also be widely used in other diverse scenarios. Among them, millimeter wave radar has extremely important technological advantages in the field of intelligent transportation.
Millimeter wave radar has great potential in the field of intelligent transportation
According to statistics from the Ministry of Public Security, in 2018, there were 31.72 million newly registered motor vehicles in China, and the total number of motor vehicles has reached 327 million, including 240 million cars. For the first time, the number of small passenger cars has exceeded 200 million. The increasingly complex road traffic environment has prompted China's demand for intelligent transportation management systems to develop towards intelligence, comprehensiveness, accuracy, and real-time capabilities.
In actual traffic, especially at intersections and highways, sensors are used to track traffic congestion and keep roads clear. These sensors must have:
▲ Accuracy (used to measure the extension range, speed, and position of vehicles or pedestrians)
▲ Stability (unaffected by external factors such as light, dust, rain, and snow)
▲ Integrity (optimizing real-time evaluation and correction)
▲ Easy to use (with reference code and samples to accelerate deployment)
At present, detection methods such as big data, geomagnetism, video, and radar can provide multimodal data, among which the technical advantages of millimeter wave radar have extremely important applications in the field of intelligent transportation.
Millimeter wave radar can collect objective and effective road traffic information, obtain basic data such as traffic flow, speed, vehicle type, etc., thereby realizing intelligent means such as monitoring, control, analysis, decision-making, scheduling, and guidance, providing valuable insights for traffic management
Provide technical support through intelligent technology. At present, millimeter wave radar can be mainly applied in the field of intelligent transportation for vehicle detection, traffic flow investigation, entrance and exit vehicle management, speeding monitoring, signal light control, and other aspects.
1. Overspeed monitoring
The multi lane and multi-target tracking radar designed for speed measurement can provide accurate vehicle speed and positioning information, ensuring the capture of every speeding car on the detection section. It has the characteristics of high precision, easy debugging, and high stability, providing accurate, reliable, and real-time traffic intelligence for traffic management departments and ensuring the normal operation of the traffic management system.
2 Traffic flow detection
Urban transportation is multidimensional and complex, and solving traffic congestion problems is a long and arduous task. In the past few years, traffic flow collection has mainly been used for video capture. Although it has the advantage of visualization, it is greatly affected by weather and has large errors. At the same time, the distance for video detection is very limited, and it can only reach up to 80 meters at night. Millimeter wave, as a non-contact sensing technology, can be used to detect objects and provide information on their distance, velocity, and angle. In addition, millimeter waves can penetrate specific materials such as plastic, wall panels, and clothing, and are not affected by environmental conditions such as rain, fog, dust, and snow. The integration of millimeter wave radar and video can achieve the function of "visualized high-precision data large area detection", making traffic parameter perception more diverse and accurate, bringing a safer, smoother, more environmentally friendly, and smarter road traffic environment.
3 Vehicle management at the entrance and exit
With the rapid increase in the number of cars, the requirements for vehicle management systems at regional entrances and exits are becoming increasingly high. In the past, sensors used to manage vehicle and personnel entrances and exits mainly relied on cameras, infrared radiation, and ground sensing coils. The performance of the camera will be affected in complex weather conditions such as night and haze, making it difficult to work 24/7; Infrared installation requires alignment on both sides, resulting in slightly lower resistance to environmental interference and reliability. In contrast, millimeter wave radar has obvious advantages. Its construction and installation are simple, and later debugging, maintenance, and upgrading are more convenient, and it is not affected by environmental conditions such as rain, fog, dust, and snow. At the same time, millimeter wave radar has a high capture rate for passing vehicles, which can effectively avoid false alarms, false negatives, or vehicle smashing incidents, effectively compensating for the shortcomings of ground sensing coils and infrared radiation in identifying people, and has obvious anti smashing functions.
4 Signal light control
Crossroads are important nodes on urban roads, and signal control is a crucial means of regulating traffic flow. The traffic signal can obtain information such as traffic flow and queue length from the traffic monitoring equipment at the intersection, integrate data from various directions, adjust the timing of each phase, and improve the traffic efficiency at the intersection. And all of these are based on real-time, reliable, and trustworthy data detection and collection. Millimeter wave radar, with its unique advantages, can play an important role in this regard. Millimeter wave radar can detect the starting position, queue length, number of queued vehicles, average vehicle speed, and other information of multiple lanes. At the same time, it can detect the passing information of each vehicle on multiple lanes, such as vehicle speed, model, lane number, and occupancy time. It can optimize the timing scheme of traffic lights at intersections, dynamically adjust the setting time of traffic lights in each lane of the traffic signal control machine, improve the traffic efficiency at intersections, and reduce congestion.
In recent years, many Chinese companies have continuously increased their research and development efforts, and have made certain breakthroughs in the field of millimeter wave radar, which has broad prospects for industrial development, with intelligent transportation radar as the main application direction. Among them, there are companies such as Sensitech, Anzhijie, Chengtai, Mozhibi, Huayu, OCULII, Anzhi, and Furuitech
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