The Flight Control System of the Hovereye® VTOL UAV

This overview paper covers the flight control system of Bertin Technologies’ Hovereye ® mini vertical takeoff and landing (VTOL) UAV, including development, verification in simulation and flight test results. Hovereye ® is a demonstrator of a short range reconnaissance platform in support of army units engaged in urban combat, such as in peace-keeping missions, with an electro-optic day or night camera payload.. This system stabilizes the vehicle, provides operators with easy manual flight commands, and automatically performs mission segments such as automatic landing, in the face of strong gusting wind. The highlights of this paper are: the breadth of its scope, covering a full UAV flight control system, with a special emphasis on control laws; the proposed rapid prototyping solutions have been proven in flight; some experimental results are given; insight is provided into the stabilisation of the unconventional ducted-fan VTOL configuration, which is open-loop unstable and features highly nonlinear dynamics; issues on semi-automatic and autonomous flight are dealt with, including visual-based servo control;. Short films of test flights will complete the presentation. 1 Flight Control System Manager 2 UAV Systems Manager 3 Researcher 4 Professor 5 Professor 6 Guidance & Control Engineer RTO-MP-AVT-146 34 1 UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED The Flight Control System of the Hovereye® VTOL UAV Binetti, P.; Trouchet, D.; Pollini, L.; Innocenti, M.; Hamel, T.; Le Bras, F. (2007) The Flight Control System of the Hovereye® VTOL UAV. In Platform Innovations and System Integration for Unmanned Air, Land and Sea Vehicles (AVT-SCI Joint Symposium) (pp. 34-1 – 34-16). Meeting Proceedings RTO-MP-AVT-146, Paper 34. Neuilly-sur-Seine, France: RTO. Available from: http://www.rto.nato.int/abstracts.asp. Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 01 NOV 2007 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE The Flight Control System of the Hovereye® VTOL UAV 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Bertin Technologies, UAV Systems Parc dactivités du Pas du Lac 10bis, avenue Ampère 78180 Montigny-le-Bretonneux, BP 284, France 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release, distribution unlimited 13. SUPPLEMENTARY NOTES See also ADM202416., The original document contains color images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 16 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 1.0 INTRODUCTION This overview paper is about the flight control system of Bertin Technologies’ Hovereye ® mini VTOL unmanned aerial vehicle (UAV). This system stabilizes the vehicle, provides operators with easy manual flight commands, and automatically performs mission segments such as automatic landing, in the face of strong gusting wind. Its design is particularly challenging. 1.1 Motivation and state of the art A thorough documented practical approach for the design of the GN&C system for such vehicles does not exist, although interesting papers are available [17]. In addition the dynamics of ducted-fan configurations is poorly known and stabilization and control are not yet fully tackled: • Flight in gusting wind is a major challenge [2], [20] • Aggressive maneuvering has not been mastered (it has for helicopters at MIT [30]) • Envelope protection for carefree flying has never been treated In literature: plain linear approaches are fine, but only good for a limited envelope [15], [16]; nonlinear approaches are either too complex [18], or too dependent on knowledge of system dynamics [21], or fail to provide quantitative indications of performance, stability and robustness. 1.2 Scope and highlights The paper covers the flight control system of the Hovereye ® UAV, including development, verification in simulation, and flight test. In addition, in the next chapter a quick introduction is given to the Hovereye ® system, including a description of the platform and its ground segment, with special emphasis on the flight control system’s avionics architecture and sensor suite.