Toshiba’s new circuit technology realizes long-range LiDAR for self-driving vehicles

Toshiba Corporation has developed a new circuit technology for an automotive LiDAR which enables long-range distance measurement while capturing high quality 3D images, securing a major advance in a technology essential for self-driving vehicles. The developed LiDAR using the proposed circuit achieves a measurement range of 200m, which is world’s highest and twice than that of conventional automobile LiDARs.

 

The biggest challenge in long distance LiDAR is conducting measurements under bright sunlight, which generates large noise. By utilizing an analog-to-digital converter (ADC)  and signal processing, the sunlight noise can be suppressed. However, ADCs do not support the high-speed processing necessary to provide accurate short distance measurements required for parking assistances. Furthermore, the 3D image resolution is degraded when reflected laser light comes from multiple objects, since current signal processing is averaging, the image becomes ‘blurred’. This increases the possibility of overlooking small objects such as pedestrians.

Toshiba’s solution is utilizing a hybrid of two circuits: one for measuring short distances and an ADC circuit for measuring long distance. Relaxing the processing speed required for the ADC circuit enables realization of long distance measurement. Performance is further enhanced by Toshiba’s newly developed smart averaging technique. The new technique solves the problem of conventional signal processing by determining whether the reflected signals of multiple lasers are from the same or different objects, therefore the image becomes ‘sharpened’ and the LiDAR image resolution significantly improves. The combination of the hybrid circuit and the smart averaging technique makes it possible to push the LiDAR sensor range to 200m and simultaneously enables the detection of small objects.

The unique structure of Toshiba’s new ADC circuit realizes a small circuit size and low-power consumption circuit, opening the way to building high-performance, compact LiDAR systems outperforming current systems.

Details of the technology were announced at the 2018 IEEE International Solid-State Circuits Conference (ISSCC) held in the United States San Francisco on February 12.

Toshiba will continue R&D in driving support and autonomous driving systems, where development is progressing toward practical application, and will contribute to the realization of sophisticated autonomous driving systems.

Source: Toshiba