Real Time Imaging Rangefinder For Autonomous Land Vehicles

Abstract

A three-dimensional sensor that achieves 50 microsteradian resolution over a 90 X 40 degree field of view (FOV) at full video frame rates has been designed for robotic vehicles. A combination of coarse and fine range resolution provides sensing from one to approximately 100 meters with short-range accuracies of less than 10 cm. The system utilizes an eyesafe diode laser configuration along with proprietary mechanical scanning elements, wide-field relay optics, and avalanche photodiode detectors. Range determination is accomplished with dual subcarrier modulation which results in the output of an unambiguous, binary word on a pixel-by-pixel basis. The approach also provides for electronic pitch stabilization.