An Overview of LiDAR Requirements and Techniques for Autonomous Driving

The most recent research and development efforts regarding autonomous driving have led to the demand for competitive automotive-grade sensors, which must be capable of meeting a wide variety of stringent requirements. Light detection and ranging (LiDAR) systems are fundamental sensors for the machine vision task of advanced driver-assistance systems (ADAS). The main principles and main requirements of automotive LiDAR, such as high range, sub-centimeter precision, low power consumption, low manufacturing cost and eye-safe signal transmission, are presented in this paper. Several distinct LiDAR time of flight estimation techniques that are currently being pursued, including time-to-digital converter (TDC), full-waveform, continuous wave and photon-counting LiDAR are discussed and examples of their possible applications are described. Considerations regarding the proper design of LiDAR transmitter and receiver architectures are also addressed. In spite of most of the existent automotive LiDAR systems being based on TDC, it is envisaged that full-waveform techniques have more margin for improvement and show promise in achieving automotive-grade performance in the near future.