Biblio

Offloading computationally expensive Simultaneous Localization and Mapping (SLAM) task for mobile robots have attracted significant attention during the last few years. Lack of powerful on-board compute capability in these energy constrained mobile robots and rapid advancement in compute cloud access technologies laid the foundation for development of several Cloud Robotics platforms that enabled parallel execution of computationally expensive robotic algorithms, especially involving multiple robots. In this work the Cloud Robotics concept is extended to include the current emphasis of computing at the network edge nodes along with the Cloud. The requirements and advantages of using edge nodes for computation offloading over remote cloud or local robot clusters are discussed with reference to the ETSI 'Mobile-Edge Computing' initiative and OpenFog Consortium's 'OpenFog Architecture'. A Particle Filter algorithm for SLAM is modified and implemented for offloading in a multi-tier edge+cloud setup. Additionally a model is proposed for offloading decision in such a setup with experiments and results demonstrating the efficacy of the proposed dynamic offloading scheme over static offloading strategies.

This paper describes Smartpig, an algorithm for the iterative mosaicking of images of a planar surface using a unique parameterization which decomposes inter-image projective warps into camera intrinsics, fronto-parallel projections, and inter-image similarities. The constraints resulting from the inter-image alignments within an image set are stored in an undirected graph structure allowing efficient optimization of image projections on the plane. Camera pose is also directly recoverable from the graph, making Smartpig a feasible solution to the problem of simultaneous location and mapping (SLAM). Smartpig is demonstrated on a set of 144 high resolution aerial images and evaluated with a number of metrics against ground control.

We propose a dense continuous-time tracking and mapping method for RGB-D cameras. We parametrize the camera trajectory using continuous B-splines and optimize the trajectory through dense, direct image alignment. Our method also directly models rolling shutter in both RGB and depth images within the optimization, which improves tracking and reconstruction quality for low-cost CMOS sensors. Using a continuous trajectory representation has a number of advantages over a discrete-time representation (e.g. camera poses at the frame interval). With splines, less variables need to be optimized than with a discrete representation, since the trajectory can be represented with fewer control points than frames. Splines also naturally include smoothness constraints on derivatives of the trajectory estimate. Finally, the continuous trajectory representation allows to compensate for rolling shutter effects, since a pose estimate is available at any exposure time of an image. Our approach demonstrates superior quality in tracking and reconstruction compared to approaches with discrete-time or global shutter assumptions.