Lidar technology research and development difficulties

System complexity leads to excessive LiDAR volume

Lidar, in short, is a high-precision sensor that realizes three-dimensional detection by actively transmitting and receiving laser signals. The working principle of laser radar is similar to that of microwave radar. The laser is used as a signal source, and the laser signal reaches the target surface-trees, roads, Bridges, buildings, etc., generate backscattering on the surface of the target, thereby returning a portion of the laser echo signal back to the receiver of the laser radar. Then, through photoelectric signal conversion and signal processing, the laser ranging calculation is realized, that is, the target point ranging is obtained. After the laser signal scans the surface of the target, the data of the three-dimensional point on the surface of the target can also be obtained. After using the data for three-dimensional imaging processing, we have accurate three-dimensional target model data (target stereogram).

The core performance indicators of the international advanced mapping laser radar include: km-level ranging range, millimeter-scale ranging accuracy, and millions of laser emission frequencies. This requires highly optimized lidar system design techniques, especially the fine and real-time processing capabilities of lidar signals, including weak signal acquisition and amplification, noise identification and filtering, and time accurate metering, spatial position information and reflection intensity information. Transient measurements, etc.

Since the light is transmitted at a very high speed, the above-mentioned signal reception, processing, and three-dimensional data generation are completed in a very short time (nanoseconds), which is very difficult. Lidar is by far one of the most complex, most efficient and accurate sensors. Compared with cameras, it has more modules for active illumination and optical signal modulation and demodulation, achieving millions of accurate measurements per second. A complex integrated system.

However, such a complex integrated system also makes the integrated circuit design a roadblock for the development of laser radar technology. The complicated assembly of a large number of laser radars makes the laser radar too bulky and inconvenient to use.