V2X Sensors: LiDAR and Radar

V2X sensors mainly include Radio Detection and Ranging (RADAR), Light Detection and Ranging (LiDAR), and Optical Sensors (Cameras).

From the general direction, it is mainly divided into road end and vehicle end. Based on advanced wireless communication and new-generation Internet technologies, V2X is to implement dynamic real-time information interaction between vehicles and vehicles, and vehicles to roads, and to carry out vehicle active safety control and road coordination management based on entire space-time dynamic traffic information collection and fusion. V2X can fully realize the effective coordination of people, vehicles, and roads, to ensure traffic safety and improve traffic efficiency, to build a safe, efficient, and environmentally friendly road traffic system.

Typical application scenarios of V2X include blind-spot warning, multi-vehicle coordinated lane change, intersection collision avoidance, pedestrian &non-motor vehicle collision avoidance, emergency vehicle priority passing, vehicle speed guidance, fleet control, and fleet coordinated passing signalized intersections, etc.

I. Millimeter-wave radar:

As one of the important V2X sensors, millimeter-wave radar is a radar that works in the millimeter-wave band and can measure the relative distance, speed, and azimuth of the measured objects. Millimeter waves are essentially electromagnetic waves, with frequencies higher than radios and lower than visible light and infrared, with frequencies ranging from 10GHz to 200GHz.

II. LiDAR:

LiDAR is also one of the important V2X sensor roles. It mainly transmits a detection signal (laser beam) to the target. It then compares the received signal (target echo) reflected from the target with the transmitted signal. After processing, the relevant information of the target can be obtained, such as target distance, azimuth, height, speed, attitude, shape, etc.

III. Performance comparison  

Performance	Radar	LiDAR (1550nm)
Ranging/speed measurement	high vertical accuracy, low horizontal accuracy	high precision
Perception distance	up to 200 meters	up to 600 meters
Pedestrian and object recognition	fail to identify	3D modeling
Road marking	fail to identify	identifiable
Bad weather	not affected	less affected
Illumination	not affected	not affected
EMI/EMI shielding	susceptible	not affected
Algorithm, Technology maturity	higher	high, developing rapidly
Cost	higher	high

1. In terms of detection accuracy: the detection distance of millimeter-wave radar is directly restricted by the loss of the frequency band (if you want to detect far, you must use high-frequency radar), this V2X sensor cannot sense pedestrians, and cannot accurately model all surrounding obstacles.

2. In terms of anti-interference: LiDAR detects by emitting a beam, which is greatly affected by the environment. The beam will not work normally if it is blocked, so this V2X sensor cannot perform well in bad weather such as rain, snow, haze, and sandstorms. While millimeter-wave radar has a strong ability to penetrate fog, smoke, and dust, it can detect the environment in bad weather.

3. In terms of cost: Because the amount of data obtained by LiDAR is far more than that of millimeter-wave radar, it requires a higher-performance processor to process the data, so the cost is relatively higher.

IV. The status quo of V2X development:

On the car side: With the development of autonomous driving technology, two major categories have gradually formed: pure vision system and LiDAR-based system. New Energy Vehicles companies such as Waymo, Cruise, Baidu, Huawei, Didi, Pony.ai, Nio, Xpeng, and Li Auto all use LiDAR-based multi-sensor fusion solutions. While representative companies that firmly claim to take the pure vision solution include Tesla and Toyota.

On the roadside: The common practice is to combine the V2X system with smart street lights, and build a smart city V2X system based on the 5G network through sensors. In the face of different traffic scenarios at the roadside and the complex conditions of the road, different V2X sensors, including cameras, millimeter-wave radars, and LiDARs, will be used to give full play to their respective advantages and complement each other.

Neuvition. Inc has rich experience in the application of V2X. As a top-quality V2X sensor, Neuvition LiDAR has helped customers to achieve the following functions:

1. Detection output of vehicle L*W*H, vehicle speed, etc;

2. Real-time location output, ID detection&tracking;

3. Data fusion of cameras, LiDARs, and other sensors;

4. System calibration, providing information such as longitude, latitude, direction, and angle. To help customers solve problems such as over-limit (length, width, height) detection, road congestion, danger ahead, overspeed, and tunnel safety.