Concept Design of a Scanning Laser Rangefinder for Autonomous Vehicles

Abstract

This report specifies a scanning laser rangefinder which is specifically designed for high speed autonomous vehicles. This new scanner, called Tornado, represents a departure from conventional sensors in that it looks farther downrange in order to detect obstacles earlier. This made it possible to maintain a wide horizontal field of view, good obstacle resolving power, high throughput and good uniformity of the scan all at the same time. Tornado utilizes a narrow vertical field of view and a programmable vertical scan in order to achieve this. While this report is not written to evaluate the performance limitations imposed by the current HMMWV configuration, it is clear from the analysis that the ERIM sensor is poorly suited to high speed off road navigation. For this reason, the Tornado scanner must be constructed in order to achieve 20 m.p.h. speeds. A simple, general kinematic theory is presented which encompasses the kinematics transforms for all existing laser rangefinders. A short study of the design constraints that limit rangefinder performance is presented. The results of this work provide useful relationships for reference purposes.