Multi-rotor systems and helicopters with multi-joint robotic arms can perform manipulation tasks while flying, such as building structures or deploy equipment in otherwise inaccessible sites.

Published Tuesday, 16 September, 2014
Updated Thursday, 30 July, 2015

 

This is a guest blog post by Anibal Ollero, Coordinator of the ARCAS project, professor at the University of Seville and Scientific Advisor of FADA-CATEC

Work at heights

Works at height could be very dangerous and difficult. Imagine for example installation and maintenance works in communication towers or in skyscrapers. The same applies to electrical lines, wind turbines, high pipes in refineries just to mention a few. These works require scaffolding, or climbing using rigging systems and are either dangerous or costly or both.

Search and rescue, or post disaster intervention in general, also require aerial transportation to otherwise inaccessible sites. In such cases piloted aircrafts and particularly helicopters are used. They are also deployed in some of the above mentioned maintenance activities. However, again we encounter the same problems: danger, because of flying close to obstacles and high costs.

Aerial robotic manipulation

Aerial robots, or drones, are increasingly appearing in the media and the commercial possibilities are many. In most proposed applications the robot is a flying camera that takes images or, in a more general way, a platform to install sensors. However, in many cases, this is not enough to get the task completed and, in the end, people have to perform the work manually with important risk and very costly means.

Until now, small quadrotors, only perform in the laboratory simple pick and place and grasping. The ARCAS project (http://www.arcas-project.eu) has gone a step further: it demonstrates that more complex robotic manipulation activities, involving perception and planning,  are possible. The aerial robotic manipulators in ARCAS have arms with 6 and 7 joints allowing the aerial robots to perform more complex manipulation tasks, in any position and orientation, compensating for the perturbations on the aerial platform hovering due to the motion of the arm, the wind,  and the physical contact with objects.

Demonstration

Have a look at our short indoor and outdoor demo!

The indoor experiments have been carried out by the ARCAS consortium in the flying arena of the aerospace technology centre FADA-CATEC in Seville. The aerial robotic manipulator consisted of a multi-rotor system with a very light arm, with 6 joints, designed in the project as a tradeoff to minimize the weight to be transported by the multi-rotor and maximize the reach and manipulation capabilities. The aerial manipulators integrate autonomous perception and planning capabilities to compute collision free efficient trajectories. Moreover, the aerial manipulators are members of a team of aerial robots that are able to work together, performing tasks such as mapping the field and providing the information required for autonomous manipulation in unknown fields. The aerial robots are coordinated to avoid collisions between them and with objects in the environment, optimizing the energy and time of flight to perform the cooperative missions.

The outdoor demonstrations have been performed at the facilities of DLR, the German national aerospace research centre, near Munich, and at the University of Seville.

In Germany an autonomous helicopter, with improved configuration to optimize time of flight and payload, has been equipped with an industrial arm with 7 joints demonstrating grasping and transportation of bars. In Spain, a multirotor system has been equipped with another arm with 7 joints also demonstrating grasping and transportation. The integrated control of the aerial platform and the arm with 7 joints is important to perform the manipulation even in case of wind perturbations.

Check out the robots in action in this Euronews video!

Conclusion

The ARCAS methods and technologies have a huge potential in many application fields including the above mentioned inspection and maintenance activities (chimneys, pipes, electrical lines, wind turbines, … ), installations in inaccessible sites such as antennas on top of a mountain,  and helping in the search and rescue activities, such as the installation of platforms to evacuate people.

The project partners would be eager to exchange methodologies and techniques with other experts in the field of robotic control, perception and planning methods as well as new designs of aerial platforms, light arms and grasping devices.

We are also looking into complementary technologies that can improve the flight endurance or decrease the risk in the operation of the aerial robot.

In conclusion, if you think that aerial robotic manipulation is useful for your area of interest, please let us know and follow the developments of ARCAS!