Future Work:

There are several aspects of this project that could be improved further, first and fore most is successful flight testing. Even though HILS simulations performed more than adequately for successful autonomous takeoff and landings, actual flight have presented many problems.

One of the challenges that arises during actual flight testing is that the IR sensors that the miniFCS use for attitude estimation are very weather dependent, where an overcast day could interfere with attitude estimation, also IR attitude estimation is not as accurate as an IMU’s attitude estimation, where IMUs are traditionally much more expensive than IR sensors. To overcome this problem, the IR sensors cold be replaced with a low cost attitude heading reference system (AHRS) using a Kalman filter based IMU that has been produced by the VCU UAV lab [32].

A newly developed flight control system developed at VCU provides improved peripheral support (I2C, SPI communication) for HAG sensors and has the AHRS developed in [32] already integrated into the board. The ARIES FCS [33] was under development in the VCU UAV lab during the course of this thesis work and was therefore not an option for developing these ATOL algorithms. The ultimate goal would be to port the ATOL algorithms designed on the miniFCS to the new ARIES FCS. The combination of a better peripheral support of the addition of HAG sensors and integration of the AHRS replacing the IR sensors would provide a much better option for flight tests.

The largest challenge is that even though PID parameters used in simulation perform more than adequately in HILS simulations, in actual flight tests the PID parameters used in simulation do not work in actual flight tests. The majority of time during flight testing of this project was spent tuning PID parameters for all the additional controllers added while the aircraft was in the air. This is due to the fact that the flight dynamic properties of the aircraft used in simulation are

81

not the same as the aircraft used in flight testing. It would be very beneficial to be able to model the Mig aircraft used for actual flight testing and be able to use that model in FlightGear so that the PID parameters used for simulation would also work for flight tests.

Finally, once the ATOL algorithms were successfully flight tested several times on the ARIES FCS, a very attractive safety feature could be added. In the event that the aircraft detects a GCS or RC loss (where the aircraft losses contact with the ground control station or with the remote pilot) due to modem failure or the aircraft has gone out of communication range, the aircraft is very likely to crash. With the implementation of the ATOL algorithms, if the FCS detects a loss between the GCS or RC pilot, the FCS could enter a return to base mode (RTB) where the aircraft could return to the GCS location and loiter for a short period of time trying to reestablish contact with the remote pilot or GCS; if contact is not reestablished in a reasonable amount of time the FCS could then autonomously start the autonomous landing sequence and safely land the aircraft. This is a very significant safety feature that could prevent the aircrafts certain destruction if link is lost between either the remote pilot or GCS.

82

Bibliography

[1]

T. H. Cox, C. J. Nagy, M. A. Skoog, I. A. Somers and R. Warner, "UAV Assessment Report Overview, Executive Summary of Civil Assessment Document," NASA, 2005.

[2]

R. G. Arrabito, G. Ho, A. Lambert, M. Rutley, J. Keillor, A. Chiu, H. Au and M. hou, "Human Factors Issues for controlling Uninhabited Aerial Vehicles," Defense R&D Canada, Toronto, 2010.

[3]

P. C. P. Garrec, "MAGIC ATOLS: Microwave and GPS Integrated Cooperative Automatic Take-Off and Landing System," in International Congress of the Aeronautical Sciences, Nice, 2010.

[4]

J.-C. Roos and P. I. K., "Autonomous Take-Off and Landing of a Low Cost Unmanned Aerial Vehicle," R & D Journal of the South African Institution of Mechanical

Engineering, vol. 2009, no. 25, pp. 1-13, 2009.

[5]

R. John, "DefenseTech.org," Military.com, 12 November 2010. [Online]. Available: http://defensetech.org/2010/11/12/uav-auto-take-off-and-landing-could-save-serious- money/. [Accessed 2 May 2012].

[6]

J. E. Ortiz, "Development of a Low Cost Autopoilot System for Unmanned Aerial Vehicles," VCU, Richmond, 2010.

[7]

G. C. Larson, The First Autolanding, Air&Space Smithsonian, August 2012.

[8]

F. Araripe d'Oliveria, DPA-VANT Project: Automtic Take-Off and Landing - ATOL Development, Brazil: DCTA, 2011.

[9]

A. Sigworth, J. Davila, T. McNeil, J. Nicolalde, D. Scheve and K. Funk, "Mission Analysis," Covell Avionics, 14 March 2000. [Online]. Available:

83

http://flightdeck.ie.orst.edu/ElectronicChecklist/HTML/mission.html. [Accessed 10 June 2014].

[10]

REStARTS, "Phases of a Flight," REStARTS, [Online]. Available: http://www.fp7- restarts.eu/index.php/home/root/state-of-the-art/objectives/2012-02-15-11-58-37/71- book-video/parti-principles-of-flight/126-4-phases-of-a-flight. [Accessed 10 June 2014].

[11]

P. Rosa, C. Silvestre, D. Cabecinhas and R. Cunha, "Autolanding Controller for a Fixed Wing Unmanned Air Vehicle," in AIAA Guidance, Navigation and Control , Hilton Head, 2007.

[12]

Wikipedia, "Instrument Landing System," 7 April 2014. [Online]. Available:

http://en.wikipedia.org/wiki/Instrument_landing_system#Decision_altitude.2Fheight. [Accessed 10 June 2014].

[13]

C. Wood, "The Instrument Landing System," [Online]. Available: http://www.navfltsm.addr.com/ils.htm. [Accessed 10 June 2014].

[14]

termwiki, "Laser Altimeter," [Online]. Available:

http://www.termwiki.com/EN:laser_altimeter. [Accessed 10 June 2014].

[15]

Aliexpress, "Laser Altimeter Price Trends," [Online]. Available:

http://www.aliexpress.com/laser-altimeter_price.html. [Accessed 10 June 2014].

[16]

Acuity, "AR3000 Distance Measurement Sensor," [Online]. Available:

http://www.acuitylaser.com/products/item/ar3000-distance-measurement-sensor. [Accessed 10 June 2014].

[17]

RUAG Aviation, "OPATS- The Laser-based Automatic Landing System for UAVs," RUAG Aviation, [Online]. Available:

http://www.ruag.com/de/Aviation/Subsystems_Products/Aviation_Products/OPATS/FS _OPATS.pdf. [Accessed 10 June 2014].

84 [18]

Roke Manor Research Limited, "MRA - Minature Radar Altimeter," Chemring Group, 2013. [Online]. Available: http://www.miniradalt.com/mra-type-2.html. [Accessed 10 June 2014].

[19]

Thales Group, "Airborne Mission System," [Online]. Available:

https://customeronline.thalesgroup.com/en/customer-online/defence/military- aerospace/airborne-mission-system. [Accessed 10 June 2014].

[20]

Cybarcode, "Trimble NavBeacon XL," [Online]. Available:

http://cybarcode.com/trimble/gps/receiver/navbeacon_xl?gclid=CMig3tCv0b0CFRFnOg od63oAYQ. [Accessed 10 June 2014].

[21]

P. Riseborough, "Automatic Take-Off and Landing Control for Small UAV's," BAE Systems, Melbourne.

[22]

A. Cho, J. Kim, S. Lee, S. Choi, B. Lee, B. Kim, N. Park, D. Kim and C. Kee, "Fully Automatic Taxiing, Takeoff and Landing of a UAV using a Single-Antenna GPS

Receiver only," in International Conference on Control, Automation and Systems, Seoul, 2007.

[23]

D. B. Barber, S. R. Griffiths, T. W. McLain and R. W. Beard, "Autonomous Landing of Miniature Aerial Vehicles," Journal of Aerospace Computing, Information, and

Communication, vol. 4, no. 5, pp. 770-784, 2007.

[24]

K. Masuko, I. Takahashi, S. Ogawa, M.-H. Wu, A. Oosedo, T. Matsumoto, K. Go, F. Sugai, A. Konno and M. Uchiyama, "Autonomous Takeoff and Landing of an Unmanned Aerial Vehicle," in IEEE/SICE International Symposium on System Integration (SII), Sendai, 2010.

[25]

S. Duranti, "Autonomous Take Off and Landing of the SHARC Technology Demonstrator," in 25th International Congress of the Aeronautical Sciences, 2006.

[26]

I. Diaz, R. Hoffman, J. Neighbors, R. Perez, J. Peterson, M. Schoeni, M. Seifert and T. Weekes, "Team Blackbird 12'," Embry-Riddle Aeronautical University, 2012.

85 [27]

HelloTrade, "HelloTrade- Piccolo Systems," [Online]. Available:

http://www.hellotrade.com/bae-systems-tucson/piccolo-systems.html. [Accessed 10 June 2014].

[28]

G. L. Ward, "Design of a Small Form-Factor Flight Control System for Unmanned Aerial Vehicles," Virginia Commonwealth University, Richmond, 2010.

[29]

"Calculate distance, bearing and more between Latitude/Longitude points," [Online]. Available: http://www.movable-type.co.uk/scripts/latlong.html. .

[30]

"XPlane 10," [Online].

[31]

"TerraGear," [Online]. Available: wiki.flightgear.org/TerraGear.

[32]

M. T. Leccadito, "An Attitude Heading Reference System using a Low Cost Inertial Measurement Unit," VCU, Richmond, 2013.

[33]

G. L. Ward, "Design of a Small Form-Factor Flight Control System," VCU, Rightmond, 2014.