Direct measurement of the maximum detection range of an automotive lidar with a table-top setup for series production

Abstract

Recent development in the field of advanced driver assistant system (ADAS) has shown that Light Detection and Ranging (lidar) sensors are essential for 3D object detection. One of the key parameters of automotive lidar is the maximum detection range, which is dependent on background light as well as the lidar signal itself. To make lidar sensors widely accessible for the automotive market, high-volume series production becomes a necessity. Since today's sensors have a maximum detection range far beyond a hundred meters it is neither economically nor logistically viable to build a long-range setup for series production. In this work we will present a table-top setup with a length no longer than one meter, directly measuring the maximum detection range of a lidar sensor - with similar precision (about two meters for one sigma) compared to the long-range distance measurement. This setup can be used to verify the maximum detection range and execute other complementary tests like beam quality and straylight simultaneously. This is particularly important considering the cycle time restriction in series production of the automotive lidar. Our setup mainly consists of a triggerable laser and a background light source. Using the fact that the intensity of the back-scattered light is inversely proportional to the distance squared, it is possible to imitate a far-away object by tuning a laser to a reduced intensity.