Posted by Kostas Alexis on October 1, 2018 at 7:00pm
Dear community,
We would like to inform you about our participation in the DARPA Subterranean Challenge as Team CERBERUS (University of Nevada, Reno, ETH Zurich, Sierra Nevada Corporation, University of California, Berkeley, Flyability).
Please find out more for us through by watching our concept video:
Posted by Kostas Alexis on February 24, 2018 at 11:00pm
Dear community,
We would like to share the following result on aerial robotic navigation through obscurants. The test took place in a smoke-filled machine-shop environment.
Posted by Kostas Alexis on January 12, 2018 at 11:00am
This is to share results on radiation source localization in GPS-denied environments using autonomous aerial robots that estimate the nuclear (Cs-137 in the experiments) source location and intensity, while simultaneously planning for informative measurements. Smart selection of measurement points is critical as the robot has to dwell for sufficient time to allow the Poisson statistics to derive a confident measurement. The robot is equipped with CsI(Tl) scintillator with silicon photomultiplier and miniaturized electronics for counting and spectroscopy. The first video is explenatory of our approach while the following is taking place in a more realistic environment:
Additional details:
* Autopilot: PX4
* Position Controller: Linear Model Predictive Control running on an INTEL NUC (ROS)
* Localization: Visual-Inertial
* Path Planning: Explicit function to optimize for distribution of measurements
Posted by Kostas Alexis on October 26, 2017 at 7:30pm
Dear community,
In these two videos you will see some recent results on autonomous exploration of tunnels in visually-degraded (dark) conditions. Both localization and mapping, as well as path planning and control are handled completely autonomously.
This is very preliminary work on aerial robotic radiation detection in real-time and in a GPS-denied manner. The robot localizes based on visual-inertial data and integrates a deferentially installed 2-radiation detectors solution to exploit their polarity characteristics. Most of the research is ahead but we feel the topic is exciting and would like to communicate it to all of you. In this link you can get updates of our relevant work: http://www.autonomousrobotslab.com/robotics-for-nuclear-sites.html ;
As shown, it is not only referring to the radiation detection itself but also to the relevant challenges involved such as the autonomous navigation in visually-degraded environments:
We would like to share two of our recent and ongoing results related to autonomous exploration and mapping in darkness. As opposed to approaches that rely on localization based on LiDAR systems, the videos below rely on visual-inertial localization with LEDs illuminating the scene appropriately. For the first case, visible-spectrum cameras are used, while for the second near-infrared cameras are employed. We believe that operation in darkness is an important feature for aerial robotics and we would like to see more in that direction.
Posted by Kostas Alexis on January 28, 2016 at 9:53pm
Hi all,
We recently released this video on autonomous exploration and inspection. Have a look!
Summary:
The robot employs its visual-inertial navigation system in order to localize itself in the environment and simultaneously map it and 3D reconstruct it. Based on the newly proposed "Receding Horizon Next-Best-View Planner" the robot computes the next best step for efficient volumetric-exploration of unknown spaces. This is achieved by predicting a sequence of next-best-views via sampling-based methods and information gain approaches, executing only the first step and then repeating the whole process in a receding horizon fashion. Once full volumetric-exploration has been achieved, the robot starts focusing on the surface reconstruction of objects of interest in the environment.
Paper:
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
The paper is accepted and will be presented at ICRA this year.
Code:
The code is to be open sourced and will be available once the paper is presented but also before. Send us an e-mail if you have interest already and we will update you once it is out.
Previous relevant work (but at the problem of optimized inspection while known a geometrical model of the structure):
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 .
Posted by Kostas Alexis on December 16, 2014 at 6:00am
Dear members of the drones community,
For one more year... the time has come!
The Autonomous Systems Lab at ETH Zurich just released the "Autonomous Christmas Lab 2014" video! Watch and share! Robots are indeed excellent Christmas companions!
It is a great fact that UAVs tend to miniaturization. Despite the high technology advances on microprocessors and embedded systems it is clear that only simple control laws can be implemented into Miniature Autonomous Vehicles. Note that i am not talking for rf manned control but for fully autonomous solutions. So what about Wireless Sensor Network control for Drones? It is an idea implemented widely in ground robots. The main approach is to implement on-board only the main control functions (for example stabilization with simple PID loops for safety mainly when the wirelless network is not availible for some reasons) and let advanced control laws send commands from the ground station. Obvioysly the drone will also send its state vector through the network. What's your opinion?
Posted by Kostas Alexis on December 1, 2009 at 6:56am
Hi friends!I have just found and tested a Blockset that interfaces MATLAB/SIMULINK and Arduino. You may find this at:http://www.mathworks.com/matlabcentral/fileexchange/24675-arduino-targetI highly suggest this program since it offers rapid prototyping capabilities to the famous and cheap arduino. The guys have build a block that interfaces with the Real Time Workshop of MATLAB and have also implemented C functions for all arduino operations (analog in, out, serial read/write etc.). Despite the fact that the code is obviously bigger one can gain advantage from the quick and abstract way of programming that simulink offers. It is a good work!Happy coding!
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