The AIS 3D Laser Range Finder

The AIS 3D laser range finder (Fig. 1, middle) [#!RAAS2003!#,#!ISR2001!#] is built on the basis of a 2D range finder by extension with a mount and a small servodrive. The 2D laser range finder is attached in the center of rotation to the mount for achieving a controlled pitch motion and reducing torsional moments. On the left side, the high grade servo is connected. One battery charge (Scanner: 17 W, 20 NiMH cells with a capacity of 4500 mAh, Servo: 0.85 W, 4.5 V with batteries of 4500 mAh) is sufficient for 5h operating time.

The area of $180^{\circ}$(h)$\times 120^{\circ}$(v) is scanned with different horizontal (181, 361, 721) and vertical (210, 420) resolutions. A plane with 181 data points is scanned in 13 ms by the 2D laser range finder (rotating mirror device). Planes with more data points, e.g., 361, 721, duplicate or quadruplicate this time. Thus a scan with 181 $\times$ 210 data points needs 2.8 seconds. Fig. 1 (top right) shows an example of a point cloud with a viewing pose one meter behind the scanner pose.

Figure: Left: The autonomous mobile robot Kurt3D equipped with the AIS 3D laser range finder. Middle: The AIS 3D laser range finder. Its technical basis is a SICK 2D laser range finder (LMS-200). Right: Scanned scene as point cloud (viewing pose 1 meter behind scanner pose).

Figure: Left: The pan-tilt camera system. Right: Scanned scene as point cloud (viewing pose 2 meter behind scanner pose). The scene is covered by 12 camera images with some overlapping areas.