Structural inspection path planning via iterative viewpoint resampling with application to aerial robotics

Abstract

Abstract-Within this paper, a new fast algorithm that provides efficient solutions to the problem of inspection path planning for complex 3D structures is presented. The algorithm assumes a triangular mesh representation of the structure and employs an alternating two-step optimization paradigm to find good viewpoints that together provide full coverage and a connecting path that has low cost. In every iteration, the viewpoints are chosen such that the connection cost is reduced and, subsequently, the tour is optimized. Vehicle and sensor limitations are respected within both steps. Sample implementations are provided for rotorcraft and fixed-wing unmanned aerial systems. The resulting algorithm characteristics are evaluated using simulation studies as well as multiple realworld experimental test-cases with both vehicle types.

Long-Endurance Sensing and Mapping Using a Hand-Launchable Solar-Powered UAV

“…An image of the derived result is shown in Fig. 7, while additional results of autonomously executed inspection paths may be found in our previous work [1].…”

“…The overall approach is illustrated in Fig. 4, while a detailed description is available in the authors' previous work [1]. It essentially corresponds to an explicit algorithm that computes an inspection path based on a mesh-model representation of the desired world.…”

“…Prerequisite technologies have developed to the point that we are not far from the day when utilization of aerial robots is prevalent in our society. With an application range that includes infrastructure inspection [13], surveillance for security tasks [6], disaster relief [25,8], crop monitoring [7], mapping [1], and more, Unmanned Aerial Vehicles (UAVs) already provide added value to several critical and financially significant applications, and are widely acknowledged for their potential to achieve a large impact in terms of development and growth. Examples of compelling existing use-cases include the mapping of the Colorado flood area in 2003 [4], the 3D reconstruction of the "Christ the Redeemer" statue in Brazil and the Matterhorn mountain Motivated by the increasing industrial, scientific and societal demand for persistent automatic aerial sensing and surveillance, long-endurance, solar-powered fixed-wing aircrafts have been a research priority in the Autonomous Systems Lab (ASL) at ETH Zurich.…”

Information-Driven Autonomous Exploration for a Vision-Based Mav

“…Instead, we are typically interested in reconstructing a building or facade, which is not achievable by using, for example, a manipulator as done by Kriegel et al (2011). The exploration of large buildings is addressed by Bircher et al (2015). They use a Traveling Salesman Problem (TSP) solver on sampled points to compute at every iteration the shortest path for exploring a large structure with a MAV.…”

High Level Framework for Bridge Inspection Using LiDAR-Equipped UAV

“…Minimizing the number of viewpoints using Art Gallery Problem (AGP) is another approach to compute the optimal path [27,28,29]. Coverage path planning has been mostly applied on 3D-mapping [30,31], surveying of urban environments [32,33,34], ship hull inspection [28,35,36], and structural inspection [37]. The model of Bircher et al [37] which is based on Lin-Kernighan Heuristic (LKH) as a TSP solver, convex optimization, and Rapidly-exploring Random Tree star (RRT*) algorithm to define the optimized viewpoints and path, can be applied for other types of structures.…”