Scanning Laser Rangefinder for Accurate Arm Placement and Inspection M. Bualat 1 , C. Kunz 2 , J. Lavelle 3 , L. Pedersen 4 , S. Schuet 5 (1) NASA Ames Research Center, MS269-3, Moffett Field, CA 94035-1000, USA, Maria.G.Bualat@nasa.gov (2) QSS Group, Inc. at NASA ARC, MS269-3, Moffett Field, CA 94035-1000, USA, ckunz@arc.nasa.gov (3) NASA Ames Research Center, MS244-10, Moffett Field, CA 94035-1000, USA, Joseph.P.Lavelle@nasa.gov (4) QSS Group, Inc. at NASA ARC, MS269-3, Moffett Field, CA 94035-1000, USA, pedersen@email.arc.nasa.gov (5) NASA Ames Research Center, MS244-10, Moffett Field, CA 94035-1000, USA, Stefan.R.Schuet@nasa.gov ABSTRACT At NASA Ames Research Center, we have developed a novel scanning laser rangefinder that provides high- resolution models of the workspace of the K9 rover’s manipulator. These models are used to enable autonomous instrument placement against natural terrain features, such as rocks, outcrops or the ground. In this paper, we will describe the design and specifications of this scanning laser rangefinder. We will describe how the instrument has been integrated on-board the K9 rover at NASA Ames and has been used as part of an integrated demonstration of autonomous instrument placement. 1. INTRODUCTION Geological investigations, both terrestrial and on other planets, require the close-up inspection of terrain features such as outcrops and boulders. A complete investigation often requires an instrument or tool to be brought into direct contact with a feature of interest. Many instruments have a very small field of view, or require placement normal to the surface. Inaccurate placement, either in position or orientation, can degrade the data. Such accurate manipulation and placement is predicated on precise information about the shape and location of the feature. Without such a model, an autonomous instrument placement command would likely result in inaccurate placement or even damage to the instrument. Stereo vision, currently the standard tool for sensing a rover's environment, produces surface maps of varying quality and is susceptible to lighting changes and shadows. Our 3D sensing system is capable of scanning an object at very high speeds (greater than 500,000 3D points per second) and creating high-resolution 3D surface maps. Laser triangulation is used in conjunction with a high- resolution camera, a laser diode, and processing electronics all incorporated into a small sensor package that rotates from a fixed position to scan an object. Processing is done on board the instrument and the resultant 3D data is transmitted to the K9 computer. This results in rapid scans, with 3D images produced as the instrument is scanning. 2. K9 ROVER Fig. 1 K9 Rover autonomously places a microscopic camera to examine a rock target in the NASA Ames Marscape. K9, FIDO and Rocky 8 are currently the highest fidelity Mars rover prototypes available for upcoming NASA missions, and are based on a 6-wheel steer, 6-wheel drive rocker-bogey chassis designed by JPL. They are all outfitted with electronics and instruments appropriate for supporting research relevant to remote science exploration. Each rover has different avionics and instrumentation, with some overlaps between the rovers (for instance, K9 and Rocky 8 use the same IEEE 1394 cameras for navigation and obstacle avoidance). The computing onboard K9 is performed by a 1.2 GHz Pentium-M laptop running the Linux operating system. The avionics of the K9 rover have been specifically designed to enable simulation of realistic mission power constraints and science operations [1]. Low-power subsystems that can be commanded on and off and Li- ion batteries with state of charge monitors allow planning and execution systems on-board to reason and act on resource availability. The rover has a 5 degree- of-freedom arm with a reach of 70 cm that is based on the FIDO rover arm design developed at JPL. Proc. of 'The 8th International Symposium on Artifical Intelligence, Robotics and Automation in Space - iSAIRAS’, Munich, Germany. 5-8 September 2005, (ESA SP-603, August 2005)