CENPRA
From high up, monitoring, sensing and studying forests and agricultural and industrial areas CENPRADeveloping technology for operating robotic unmanned airships for use in remote sensing, environmental monitoring and aerial inspection. This is the focus of the studies by researchers from the Robotics and Computer Vision Laboratory (LRVC) at the Renato Archer Research Center (CenPRA), of the Ministry of Science and Technology (MCT), located in Campinas. They are working on the Aurora Project, an acronym for Autonomous Unmanned Remote Monitoring Robotic Airship, regarded as one of the most advanced programs for developing this kind of aircraft on the planet.
CenPRA’s airship takes off with the assistance of operators and automatically follows a previously designated flight path. This kind of apparatus has a vast field of applications. It can be employed in the monitoring and study of forests and regions of ecological interest, such as the Amazon basin. It carries out surveys in rural areas on farming and cattle raising aspects, such as the cover or use of the land, assessing crops and the number of animals. It can also help with measuring the composition of the air and levels of pollution, and its dispersion in urban and industrial centers. Furthermore, the robotic airship can inspect large structures – like oil and gas pipelines and transmission lines -, surveying urban occupation and topographical, mineral and archeological prospecting. Applications in public security or surveillance are also on the list of uses for this aerial vehicle.
Unmanned airships, already marketed in the United States and Europe, work like model aircraft, through ground radio control. Aurora intends to advance in this field, proposing as the project’s largest scientific and technological contribution the conception of the software needed for the vehicle’s autonomous operation, at a level not yet found in the American and European markets. This includes innovative aspects that range from the control algorithms for stabilizing the aircraft in flight and for following its path, to a superior hierarchical level comprising intelligence for perceiving, diagnosing and making decisions, factors needed for the autonomous operation of the robotic airship.
Aurora was started in 1997. The first flight of the unmanned airship in semi-autonomous operation took place in March 2000. The researchers’ objective is to attain completely autonomous flight. “The term autonomous refers to the capacity for perceiving and making decisions on board, making the vehicle capable of carrying out missions defined before the flight, altering its execution if necessary, without the constant need for a human operator,” clarifies electronic engineer Samuel Siqueira Bueno, the coordinator of Aurora and of the LRVC. Accordingly, the vehicle should have the “intelligence” necessary for following paths, bypassing obstacles and avoiding zones of turbulence, for example.
From 1998, Aurora started to enjoy funds from FAPESP’s Young Researcher program, originally coordinated by Marcel Bergerman and, next, by Ely Carneiro de Paiva, both engineers and holders of grants from the Foundation. In the ambit of this project, Aurora has brought CenPRA one doctorate and four master’s degrees. In all, Aurora has received over R$ 1 million, adding up finance from FAPESP, the Financier of Studies and Projects (Finep), the National Council for Scientific and Technological Development (CNPq), the Sectorial Fund for Petroleum (CT-Petro) and from CenPRA itself.
The breadth of applications for the robotic airship is due, in part, to this vehicle’s unique characteristics, such as the fact that it is held up in a predominantly aerostatic way, a condition in which the aircraft navigates sustained by gases lighter than air. Planes and helicopters fly based on the lift that the air gives the wings of these aircraft (which in helicopters are rotating) at a given speed. Thanks to the kind of lift, airships spend less fuel to move themselves and to compensate for external disturbances, like the winds. Robotic airships use small propellers as a source of propulsion and articulated parts on the surfaces of their bodies for changing their direction. These propellers are driven by an internal combustion engine that runs on hydrocarbon, a fuel used in model aircraft.
Other important characteristics of these airships are their capacity for flying at low altitudes, from dozens to hundreds of meters, at about 20 km/h, for example. This is how they can fly hovering over areas of interest. They also have advantages in their high autonomy in flight and their capacity for landing and taking off vertically without any need for specific infrastructure, such as landing strips. Finally, in the case of any fault, airships are far safer vehicles, because they come down slowly and do not fall abruptly.
Model aircraft transformed
Aurora was planned to be a long-term program with multiple stages. The first of them, currently under way, intends to establish the project’s technological basis, to validate it experimentally, and to carry out applications of a low complexity that can corroborate the concept developed. To reach these objectives, in 1998 the CenPRA acquired, in England, an AS800 airship, a common apparatus that can be piloted like a model aircraft, by means of radio control from the ground, and is manufactured by a company called Airspeed Airships. The AS800 has an inflatable body that measures 10.5 meters in length, 3 meters in diameter and has a volume of 34 cubic meters, which is filled with helium gas. It has the capacity for carrying a load of 10 kilos and has a maximum speed of roughly 60 km/h.
“What we are doing to the airship is taking out the human pilot and putting in an intelligent automatic pilot, run by a computer and instruments, creating a specific robotic architecture for it,” Samuel reports. To start with, several mechanical adaptations were carried out to turn the airship into a robotic vehicle. At the same time, the development of the entire non-board infrastructure was carried. This infrastructure is made up of a small dimension computer with an operating system based on the open and free Linux software, integrating such sensors as a GPS (Global Positioning System), an inertial center, a compass, wind gauges, photographic cameras in the visible and infrared spectrums and remote sensing apparatus, among others.
The researchers also developed the ground infrastructure, which consists of a laptop computer intended for the programming and operating of the vehicle, and the radio, modem and video links. “Today, it is capable of following automatically routes defined by passing points (latitude and longitude coordinates) and altitude profiles,” says Samuel. “We are now extending the automatic control to taking off and landing, procedures that no unmanned airship in the world is capable of doing.”
Another technological innovation planned for the robotic airship is the navigation system using computer vision. The objective of the researchers from the LRVC is to make the airship manage to develop routes following visual targets, going beyond geographical coordinates. This stage of Aurora’s development is being carried out in partnership with Brazilian and international institutions, such as the National Institute for Information Technology and Automation (Inria), from France, and the Higher Technological Institute (IST), from Lisbon, and the Computing Sciences Department of the Federal University of Minas Gerais (UFMG). The tests with computer vision start before the end of this semester.
Experience of flight
Up until now, the aircraft has already carried out roughly one hundred hours of flight. Adding on the preparations prior to take-off and the work up to the final anchoring of the airship in the hangar, the team has clocked up over 600 hours of experimental fieldwork. The flights take place at the 2nd Company of Armored Communication of the Army (2ª Ciacom), which is located close to CenPRA. Aurora’s second stage, forecast to be started before the end of this year, provided for the nationalization of the technology, with the manufacturing of an airship here in Brazil.
To do so, CenPRA is drawing up a project in conjunction with the Aeronautical Engineering Department of the Engineering School at the University of São Paulo (USP) in São Carlos and with Omega Aerosystem, a company from Santa Cruz da Conceição, in the region of Pirassununga (SP). “We are planning to build a medium sized unmanned robotic airships, with a payload of roughly 25 kilos, which will have a technology for autonomous navigation in a great variety of applications,” Samuel advises.
According to Aurora’s coordinator, large companies have shown interest in the project, and, in future, they may use this new technology: they include the Brazilian Agricultural Research Corporation (Embrapa), the National Institute of Research on Amazonia (Inpa), the Brazilian Institute of the Environment (Ibama), Petrobras, and the Bolivia-Brazil Gas Pipeline Brazilian Transport Company (TBG), and well as sensing and ecology groups from universities. “These companies and groups are also helping us in prospecting for applications for these robotic airships.”
Control via the Internet
Besides developing the autonomous airship, CenPRA’s Robotics and Computer Vision Laboratory (LRVC) is also studying the manipulation of robots via the Internet, in a project called Remotely Accessible Laboratory (Real). Kicked off in 1999, in cooperation with the School of Electrical Engineering and Computing at the Campinas State University (Unicamp), Real has as its objectives the creation of platforms (support software) for new applications on the Internet, such as remote access laboratories, distance learning and teleconferences. In addition, a virtual laboratory was also developed, for access, using the worldwide network, to the infrastructure of CenPRA’s mobile robots.
The virtual laboratories are important educational and experimental tools that make possible remote access to laboratory resources. They are therefore a way of compensating for the lack of resources and equipment at universities and research centers. By means of Real, researchers from institutions located in other cities and states will be able to carry out experiments with the LRVC’s mobile robots, such as the Nomad 200 and the XR4000, bought in the United States. They have several sensors and can be controlled by joysticks at a distance. The researchers are also going to interact with the robotic airship and obtain, for example, the data collected by it.
CenPRA’s virtual laboratory was developed as a telematics service on the Internet, allowing three modes of interaction between the user and the mobile robot. The first, called basic navigation, is intended for laymen, with limited knowledge of robotics, who want to manipulate the robots by means of commands. The advanced mode is aimed at researchers who want to develop and to test sophisticated algorithms for navigation. In this mode of interaction, experiments can be carried out in the field of autonomous navigation, mission planning and accompanying the control of the robot, which is carried out remotely. The third mode, called observer navigation, is dedicated to students, who can access the virtual laboratory and accompany the experiments carried out by a professor or specialist in robotics.
The interaction with the robot will be accompanied by two video channels, with real time images obtained by the use of two cameras, one panoramic focused on the environment in which the robot is moving, and the other placed on board the equipment itself. To make this virtual laboratory available to the public, CenPRA is working to put a high-speed link in place and is carrying out an update of its infrastructure.
The project
Semi-Automatic Robotic Vehicles (nº 97/13384-7); Modality Young Researcher Program; Coordinator Ely Carneiro de Paiva – CenPRA; Investment R$ 226,504.88 and US$ 3,595.33
