A technique to improve the positional accuracy of mobile ground-based LIDAR systems is proposed. Terrapoint's TITAN TM system scans the same objects at different times, so by aligning scans, any drift over time can be estimated. This paper describes a simple way of tessellating the scanned data into segments based on the vehicle's path. Principal Components Analysis is then used to estimate how well pairs of segments will align when registered with an Iterative Closest Point algorithm. The results show that this analysis does indeed find segments which are likely to register well. Finally a more formal method to analyze the results is proposed, to better determine the quality of the registration so that it can be used to improve the position estimate for the LIDAR system.Canadian Conference on Computer and Robot Vision 978-0-7695-3153-3/08 $25.00

In this work we present a method of systematically selecting regions of a haptic workspace to be used for navigation of large virtual environments. Existing navigational techniques require the partitioning of the workspace into a region of manipulation and a separate region for navigation tasks. These techniques, however, have neglected to describe an effective way to implement these concepts in a device specific manner. We propose a two step technique to define these regions based on the mechanical properties of pre-existing devices. In the first step, the kinematic properties of the device are analyzed across the entirety of the physical workspace. A well-behaved region that favours isotropic mapping from the joint actuators to the generalized forces at the end effector is selected. Having ensured high force fidelity within this region, we then perform a second step analyzing the device dynamic properties. We further subdivide the navigational space into a region with suitable inertial properties in which manipulation tasks may be performed. This procedure generates a haptic display with a highly transparent haptic manipulation region within which a user can interact with a virtual environment. This manipulation region is bounded by a well-behaved navigational region that ensures adequate force transmission. To demonstrate this technique, navigation and manipulation spaces are generated and described for the planar and spatial cases.