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Autonomous Navigation and Exploration

Upcoming ICRA 2017 Full-day Workshop: Autonomous Structural Monitoring and Maintenance using Aerial Robots, organized by Kostas Alexis, Markus W. Achtelik, Gianluca Antonelli, Margarita Chli, Anibal Ollero, Roland Siegwart, Kimon Valavanis. Further details will be posted on:  http://www.aerial-monitoring-maintenance-workshop.com/ 
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For the last year I have been working actively in the exciting field of structural inspection path planning and autonomous exploration. A glimpse of the project goals is provided within this presentation. Have a look!

Uncertainty-aware Exploration and Mapping using Aerial Robots

This planner follows a two–step, receding horizon, belief space–based approach. At first, in an online computed tree the algorithm finds the branch that optimizes the amount of space expected to be explored. The first viewpoint is selected, but the path towards it is decided through a second planning step that aims to minimized the robots expected localization uncertainty

Preliminary work on mapping in Visually-degraded Environments

These are preliminary results on exploration and mapping inside a tunnel with approximate dimensions of WIDTHxHEIGHTxLENGTH = 3x4x30m. The robot navigated along half of it (approximately) and our team evaluated the capability of localization and mapping using NIR camera/IMU, as well as Laser Time-of-Flight sensors. ​

Augmented Reality-enhanced Structural Inspection

In this work we present a methodology for augmented reality-enhanced structural inspection using aerial robots. The robot is able of autonomously computing a full coverage inspection path for a prior model of the environment, while the augmented reality-enabled user seamlessly defines new viewpoints to improve the exploration. ​

Autonomous Exploration

This video presents the results of a new Receding Horizon, Sampling-based approach to the problem of derivation of Next-Best-Views for online exploration and inspection of unknown spaces. The robot operation is fully autonomous. ​

3D Outdoors Autonomous Coverage

This video accompanies our recent paper at Autonomous Robots. The experiment took place at the ETH Zurich polyterasse and the aerial robot performed the mission autonomously both in terms of path-planning as well as vision and control. ​
 

Structural Inspection Path Planning

We released a software for structural inspection path planning and we presented its results at ICRA 2015. You can get access to both the software as well as the dataset. The planner supports both rotorcrafts as well as fixed-wing configurations.

Optimal Inspection Path Planning

This video accompanies the paper submission entitled: "An Incremental Sampling-based Approach to Inspection Planning: The Rapidly-exploring Random Tree of Trees​" which was accepted at the Robotica journal. ​

Uniform Coverage

It is quite common that during inspection operations, one does only care for full coverage but also for the uniformity of it and the focus on the details. We worked on such an algorithm and we published a relevant paper at MSC 2015. ​

Contact-based Inspection

This is an old video of EuroNews covering our final AIRobots demonstration.
Our contributions in the field can be found in the following papers: 
  • A. Bircher, K. Alexis, M. Burri, P. Oettershagen, S. Omari, T. Mantel, R. Siegwart, "Structural Inspection Path Planning via Iterative Viewpoint Resampling with Application to Aerial Robotics", IEEE International Conference on Robotics & Automation, May 26-30, 2015 (ICRA 2015), Seattle, Washington, USA
  • Kostas Alexis, Christos Papachristos, Roland Siegwart, Anthony Tzes, "Uniform Coverage Structural Inspection Path-Planning for Micro Aerial Vehicles", Multiconference on Systems and Control (MSC), 2015, Novotel Sydney Manly Pacific, Sydney Australia. 21-23 September, 2015
  • K. Alexis, G. Darivianakis, M. Burri, and R. Siegwart, "Aerial robotic contact-based inspection: planning and control", Autonomous Robots, Springer US, DOI: 10.1007/s10514-015-9485-5, ISSN: 0929-5593, http://dx.doi.org/10.1007/s10514-015-9485-5
  • A. Bircher, K. Alexis, U. Schwesinger, S. Omari, M. Burri and R. Siegwart "An Incremental Sampling–based approach to Inspection Planning: the Rapidly–exploring Random Tree Of Trees", accepted at the Robotica Journal (awaiting publication)
  • A. Bircher, M. Kamel, K. Alexis, M. Burri, P. Oettershagen, S. Omari, T. Mantel, R. Siegwart, "Three-dimensional Coverage Path Planning via Viewpoint Resampling and Tour Optimization for Aerial Robots", Autonomous Robots, Springer US, DOI: 10.1007/s10514-015-9517-1, ISSN: 1573-7527
  • A. Bircher, M. Kamel, K. Alexis, H. Oleynikova, R. Siegwart, "Receding Horizon "Next-Best-View" Planner for 3D Exploration", IEEE International Conference on Robotics and Automation 2016 (ICRA 2016), Stockholm, Sweden (Accepted - to be presented)
  • C. Papachristos, K. Alexis, L. R. G. Carrillo, A. Tzes, "Distributed Infrastructure Inspection Path Planning for Aerial Robotics subject to Time Constraints", 2016 International Conference on Unmanned Aircraft Systems, June 7-10, 2016, Atlanta, VA, USA (Accepted - to be presented)
  • ​C. Papachristos, K. Alexis, "Augmented Reality–enhanced Structural Inspection using Aerial Robots", IEEE Multi-Conference on Systems and Control 2016 Buenos Aires, Argentina, September 19-22, 2016​
  • H. Balta, J. Bedkowski, S. Govindaraj, K. Majek, P. Musialik, D. Serrano, K. Alexis, R. Siegwart, G. de Cubber, “Integrated Data Management for a Fleet of Search-and-Rescue Robots”, Journal of Field Robotics, DOI: 10.1002/rob.21651, ISSN: 1556-4967, 2016, http://dx.doi.org/10.1002/rob.21651
  • S. Khattak, C. Papachristos, K. Alexis, "Autonomous Change Detection using Aerial Robots", International Symposium of Visual Computing (ISVC) 2016, 2016, Las Vegas, US 
  • Andreas Bircher, Mina Kamel, Kostas Alexis, Helen Oleynikova, Roland Siegwart, "Receding Horizon Path Planning for 3D Exploration and Surface Inspection", Autonomous Robots, Springer US, 2016, DOI:10.1007/s10514-016-9610-0 [link]
  • Christos Papachristos, Kostas Alexis, "Autonomous Detection and Classification of Change using Aerial Robots", IEEE Aerospace Conference, 2017, Yellowstone Conference Center, Big Sky, Montana, March 4-11, 2017
  • Christos Papachristos, Shehryar Khattak, Kostas Alexis, "Uncertainty-aware Receding Horizon Exploration and Mapping using Aerial Robots", IEEE International Conference on Robotics and Automation (ICRA), May 29-June 3, 2017, Singapore
  • C. Papachristos, S. Khattak, K. Alexis, "Autonomous Exploration of Visually-Degraded Environments using Aerial Robots", International Conference on Unmanned Aircraft Systems (ICUAS), 2017
Open Source Contributions:
Released Datasets:
  • Structural Inspection Path Planning [URL]
  • Next Best View Planner Dataset [URL]
  • ICARUS project field-trials in Marche-en-Famenne: a multi-robot reconstruction of the environment [URL]
Other relevant documentation:
  • Summary presentation - February 11 2015
Relevant Online Presentations

RI Seminar: Kostas Alexis : Autonomous Exploration and Inspection using Aerial Robots

Presentation at the Robotics Institute, Carnegie Mellon University