Acronym ALTICOPTER
Funding Reference FCT - POSI/41938/CPS/2001
Dates 2002|2005
Summary

Project description: Presently, some Unmanned Air Vehicles (UAVs) exhibit a high degree of reliability in operation in the presence of dynamic and uncertain environments and challenging operating scenarios. Among the many UAV configurations available today, helicopters are one of the most manoeuvrable and versatile platforms. They can takeoff and land without a runway and can hover in place. These capabilities have brought about the use of unmanned helicopters as highly manoeuvrable sensing platforms, allowing for the access to remote and confined locations without placing human lives at risk. For these reasons, there is currently great interest in using unmanned robotic helicopters in a wide range of applications that include crop spraying, hazardous spill inspection, fire surveillance, pollution monitoring, overhead power cables inspection, bridge and building construction inspection, etc. This project focuses on the development of an unmanned robotic helicopter for precise airborne laser altimetry and surveying of disaster scenarios. The resulting system will be used to monitor the evolution of sand dunes and beaches as well as to demonstrate the usefulness of those platforms in disaster scenarios. Motivated by the high accuracy requirements of the envisaged applications as well as by the highly complex, coupled, and unstable dynamics of the helicopter, a whole range of research topics are being addressed within the framework of alticopter.

– Sensor based control for autonomous vehicles: Develop control laws that can react directly to sensor data in real time. The control strategies consist of converting the motion control problem into that of driving to zero a generalized error, defined in a suitable sensor set error space. A first laser based terrain following controller was designed and evaluated in simulation.

– Path following controllers for extended flight envelope manoeuvres: This topic addressed the study control strategies to drive the helicopter along arbitrary paths in 3D, Namely paths that can involve sudden changes on the platform angle of attack (e.g. 0 to 90 degrees). The theoretical tools required to address these problems borrow from nonlinear scheduled control theory.

– Real time distributed architectures for mission and vehicle control. This topic involved the study and development architectures to simplify the task of performing the concerted operation of the different systems resident on board autonomous vehicles.

Research Groups Computer and Robot Vision Lab (VisLab)
Dynamical Systems and Ocean Robotics Lab (DSOR)
Project Partners Instituto Geológico e Mineiro, Lisbon, Portugal
ISR/IST Responsible
Carlos Silvestre
[1] José Vasconcelos, J. Calvario, Paulo Oliveira, Carlos Silvestre, GPS aided IMU for Unmanned Air Vehicles, IAV 2004 - 5th IFAC/EURON Symposium on Intelligent Autonomous Vehicles, Lisbon, Portugal, 2004
[2] Bruno Cardeira, Carlos Silvestre, Paulo Oliveira, High Accuracy Data Acquisition Architectures for Inertial Navigation Systems, DSORL-ISR Technical Report, 2004
[3] N. Paulino, Carlos Silvestre, Rita Cunha, Preview Contollers for Affine Parameter Dependent Systems: An Application to Rotorcraft Flight Controllers, DSORL-ISR Technical Report, 2004
[4] Guilherme Libório, N. Paulino, Rita Cunha, Carlos Silvestre, Isabel Ribeiro, Terrain following preview controller for model-scale helicopters, DSORL/Mobile Robotics Labs-ISR Technical Report, 2002 - PDF
[5] Rita Cunha, Carlos Silvestre, António Pascoal, A Path Following Controller for Model-Scale Helicopters, DSORL-ISR Technical Report, 2002
[6] Rita Cunha, Carlos Silvestre, SimModHeli: A dynamic simulator for model-scale helicopters, Proc. MED2003 - 11th Mediterranean Control on Control and Automation, Rodes, Greece, 2003
[7] Guilherme Libório, N. Paulino, Rita Cunha, Carlos Silvestre, Isabel Ribeiro, Terrain following preview controller for model-scale helicopters, Proc. 11th International Conference on Advanced Robotics, ICAR 2003, Coimbra, Portugal, pp. 1227-1232, 2003
[8] Rita Cunha, Carlos Silvestre, Dynamic Modeling and Stability Analysis of Model-Scale Helicopters with Bell-Hiller Stabilizing Bar, DSORL-ISR Technical Report, 2003
[9] Rita Cunha, Carlos Silvestre, António Pascoal, A Path Following Controller for Model-Scale Helicopters, Proc. ECC 2003 - The European Control Conference, Cambridge, UK, 2003
[10] Rita Cunha, Dynamic Modeling and Stability Analysis of Model-Scale Helicopters with Bell-Hiller Stabilizing Bar, Proc. AIAA Guidance Navigation and Control Conference, Texas, USA, 2003
[11] Guilherme Libório, N. Paulino, Carlos Silvestre, Rita Cunha, Hardware in the Loop Simulation Techniques for Autonomous Helicopters, DSORL-ISR Technical Report, 2003
[12] N. Paulino, Carlos Silvestre, Rita Cunha, LMI Based H_2 Terrain Tracking Preview Controller for Unmanned Helicopters, DSORL-ISR Technical Report, 2003
[13] José Vasconcelos, J. Calvario, Paulo Oliveira, Carlos Silvestre, GPS Aided IMU for Unmanned Air Vehicles, DSORL-ISR Technical Report, 2003 - PDF