A hierarchical wavelet decomposition for continuous-time SLAM

Abstract

Abstract-This paper proposes using hierarchical wavelets as a basis in parametric continuous-time batch estimation. The need for a continuous-time robot pose in the simultaneous localization and mapping (SLAM) problem has arisen as stateof-the-art batch SLAM algorithms attempt to handle more challenging hardware; specifically, the continuous-time framework is particularly beneficial when using high-rate sensors, multiple unsynchronized sensors, or scanning sensors, such as lidar and rolling-shutter cameras, during motion. Although the traditional discrete-time SLAM formulation can be adapted by using temporal pose interpolation, approaches using the continuous-time framework are able to generate smooth robot trajectories with less state variables. In this paper, we focus on the parametric approach using temporal basis functions to develop a finite-element representation of the continuous-time robot trajectory. While the majority of current implementations have utilized a uniformly spaced B-spline basis, we note that trajectory richness is often quite variable; in this paper, we show how a hierarchical system of wavelet basis functions can be used to increase the resolution of the solution only in the temporally local regions of the trajectory that require additional detail. We validate our approach by contrasting uniform Bsplines and wavelets in a six-dimensional pose-graph SLAM experiment, using both simulated and real data.

Past, Present, and Future of Simultaneous Localization and Mapping: Toward the Robust-Perception Age

“…More abstractly, the data association module associates each measurement z k with a subset of unknown variables X k such that z k = h k (X k )+ k . Finally, the front-end might also provide an initial guess for the variables in the nonlinear optimization (4). For instance, in featurebased monocular SLAM the front-end usually takes care of the landmark initialization, by triangulating the position of the landmark from multiple views.…”

“…Robots can handle (colored) metric representation but they do not truly exploit the semantic concepts. Our robots 4 The term affordances refers to the set of possible actions on a given object/environment by a given agent [92], while the term actionability includes the expected utility of these actions. 5 Reasoning in the sense of localization and mapping.…”

Non-uniform sampling strategies for continuous correction based trajectory estimation

“…Related to this work, Oth et al [6] and Anderson et al [7] illustrate that non-uniform continuous-time trajectory representations have the potential of describing trajectories with higher level of detail when required. Nonetheless, the authors consider the problem of offline batch estimation whereas this paper focuses on online sliding window estimation.…”

Key Opinion Leaders

“…Using appearance-based lidar data in an identical fashion to this research Dong and Barfoot (2012) perform frame-to-frame motioncompensated visual odometry. Temporal basis functions for continuous-time estimation are also used in the works of Anderson et al (2014) and Oth et al (2013), which investigate how parameterizations can be chosen adaptively to prevent underfitting and overfitting the measurements. Adaptations of their work using surfels have been successful in mapping a large underground mine and estimating the irregular motion of a 2D lidar attached to the end of a spring .…”