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Laser scanners, or laser radars (ladar), have been used for a number of years for mobile robot navigation and inspection tasks. Although previous scanners were sufficient for low speed applications, they often did not have the range or angular resolution necessary for mapping at the long distances. Many also did not provide an ample field of view with high accuracy and high precision. In this paper we will present the development of state-ofthe-art, high speed, high accuracy, 3D laser radar technology. This work has been a joint effort between CMU and K2T and Z+F. The scanner mechanism provides an unobstructed 360°horizontal field of view, and a 70°vertical field of view, Resolution of the scanner is variable with a maximum resolution of approximately 0.06 degrees per pixel in both azimuth and elevation, The laser is amplitude-modulated, continuous-wave with an ambiguity interval of 52m, a range resolution of 1.6mm, and a maximum pixel rate of 625kHz. This paper will focus on the design and performance of the laser radar and will discuss several potential applications for the technology. It reports on performance data of the system including noise, drift over time, precision, and accuracy with measurements. Influences of ambient light, surface material of the target and ambient temperature for range accuracy are discussed. Example data of applications will be shown and improvements will also be discussed.

To establish mobile robot operations and to realize survey and inspection tasks, robust and precise measurements of the geometry of the 3-D environment is a required basic sensor technology. For visual inspection, surface classification, and documentation purposes, however, additional information concerning reflectance of measured objects is necessary. High-speed acquisition of both geometric and visual information is achieved by the described active ladar, developed by Zoller and Fröhlich (Z+F). In contrast to other rangesensing devices, the Z+F system is designed for high-speed and highperformance operation in real indoor and outdoor environments, emitting a minimum of near-infrared laser energy. It integrates a single-point laser measurement system and a mechanical deflection system for 3-D environmental measurements. Experimental results are reported from surface inspections in tunnels, the generation of 3-D CAD models of a work cell in an automotive manufacturing plant, the modeling of free-form surfaces such as historic sculptures, and applications in mobile robot navigation.

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