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Good Fences Make Good Neighbors

Using Formally Verified Safe Trajectories to Design a Predictive Geofence Algorithm

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NASA Formal Methods (NFM 2021)

Part of the book series: Lecture Notes in Computer Science ((LNPSE,volume 12673))

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Abstract

For AI-controlled mobile platforms, avoiding collisions with walls and boundaries is an important safety requirement. This is a problem especially for fast-moving aerial vehicles, such as fixed-wing aircraft, that cannot be brought to a stop in an emergency. To enable geographic confinement of such AI-controlled vehicles, we present a formally verified algorithm for predicting geofence violations and selecting a safe maneuver that will keep the vehicle within the designated operations area. The algorithm is based on a higher-order dynamics model that generalizes circular turns using linearly changing centripetal acceleration and allows handling of uncertainty in model parameters. The proposed algorithm was implemented along with extensions to handle non-determinism, and flight-tested on an autonomous aircraft.

Defense Nuclear Facilities Safety Board—The views expressed herein are solely those of the authors, and no official support or endorsement by the Defense Nuclear Facilities Safety Board or the U.S. Government is intended or should be inferred.

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Notes

  1. 1.

    For our purposes, we will focus on geofencing for keep-in regions only.

  2. 2.

    All theorems have been formalized and verified in Coq theorem prover, and are available at https://bitbucket.org/ykouskoulas/egeof-proofs. These proofs rely on the property – admitted as an axiom – that the shortest distance between two points is a straight line.

References

  1. Brandse, J., Mulder, M., Van Paassen, M.M.: Clothoid-augmented trajectories for perspective flight-path displays. Int. J. Aviat. Psychol. 17, 1–29 (2007)

    Article  Google Scholar 

  2. Brezak, M., Petrović, I.: Path smoothing using clothoids for differential-drive mobile robots. In: Proceedings of the 18th World Congress the International Federation of Automatic Control, IFAC 2011, Milano, Italy, 28 August – 2 September 2011, vol. 18, pp. 1133–1138 (January 2011)

    Google Scholar 

  3. Cody, W.: Chebyshev approximations for the Fresnel integrals. Math. Comput. 22(102), 450–453 (1968)

    Article  MathSciNet  Google Scholar 

  4. Dill, E.T., Young, S.D., Hayhurst, K.J.: SAFEGUARD: an assured safety net technology for UAS. In: 2016 IEEE/AIAA 35th Digital Avionics Systems Conference (DASC), pp. 1–10 (2016). https://doi.org/10.1109/DASC.2016.7778009

  5. Gilabert, R.V., Dill, E.T., Hayhurst, K.J., Young, S.D.: SAFEGUARD: progress and test results for a reliable independent on-board safety net for UAS. In: 2017 IEEE/AIAA 36th Digital Avionics Systems Conference (DASC), pp. 1–9 (2017). https://doi.org/10.1109/DASC.2017.8102087

  6. Kikutis, R., Stankūnas, J., Rudinskas, D., Masiulionis, T.: Adaptation of Dubins paths for UAV ground obstacle avoidance when using a low cost on-board GNSS sensor. Sensors 17, 2223 (2017)

    Article  Google Scholar 

  7. Kouskoulas, Y., Renshaw, D., Platzer, A., Kazanzides, P.: Certifying the safe design of a virtual fixture control algorithm for a surgical robot. In: Belta, C., Ivancic, F. (eds.) Proceedings of the 16th International Conference on Hybrid Systems: Computation and Control, HSCC 2013, Philadelphia, PA, USA, 8–11 April 2013, pp. 263–272. ACM (2013). https://doi.org/10.1145/2461328.2461369

  8. Kouskoulas, Y., Schmidt, A., Jeannin, J.B., Genin, D., Lopez, J.: Provably safe controller synthesis using safety proofs as building blocks. In: IEEE 7th International Conference on Software Engineering Research and Innovation, CONISOFT 2019, Mexico City, Mexico, 23–25 October 2019, pp. 26–35 (2019)

    Google Scholar 

  9. Levien, R.: The Euler spiral: a mathematical history. Technical report, UCB/EECS-2008-111, EECS Department, University of California, Berkeley (September 2008). http://www2.eecs.berkeley.edu/Pubs/TechRpts/2008/EECS-2008-111.html

  10. Lin, Y., Saripalli, S.: Path planning using 3d Dubins curve for unmanned aerial vehicles. In: 2014 International Conference on Unmanned Aircraft Systems (ICUAS), Orlando, FL, USA, pp. 296–304 (2014)

    Google Scholar 

  11. Loos, S.M., Renshaw, D.W., Platzer, A.: Formal verification of distributed aircraft controllers. In: Proceedings of the 16th International Conference on Hybrid Systems: Computation and Control, HSCC 2013, Philadelphia, PA, USA, 8–11 April 2013, pp. 125–130 (2013). https://doi.org/10.1145/2461328.2461350

  12. Miraglia, G., Hook, L.: Dynamic geo-fence assurance and recovery for nonholonomic autonomous aerial vehicles. In: 2017 IEEE/AIAA 36th Digital Avionics Systems Conference (DASC), St. Petersburg, FL, USA, pp. 1–7 (2017)

    Google Scholar 

  13. Monk, W.: Personal communication

    Google Scholar 

  14. Shanmugavel, M., Tsourdos, A., White, B., Żbikowski, R.: Co-operative path planning of multiple UAVs using Dubins paths with clothoid arcs. Control Eng. Pract. 18(9), 1084–1092 (2010). https://doi.org/10.1016/j.conengprac.2009.02.010

    Article  Google Scholar 

  15. Stevens, M.N., Rastgoftar, H., Atkins, E.M.: Specification and evaluation of geofence boundary violation detection algorithms. In: 2017 International Conference on Unmanned Aircraft Systems (ICUAS), Miami, FL, USA, pp. 1588–1596 (2017)

    Google Scholar 

  16. Team, P.: Px4 user guide: Geofence (2012). https://docs.px4.io/v1.10/en/flying/geofence.html. Accessed 7 Jan 2020

  17. West, M.: Track transition curves (2012). http://dynref.engr.illinois.edu/avt.html. Accessed 7 Jan 2020

  18. Wu, L., Zha, H., Xiu, C., He, Q.: Local path planning for intelligent vehicle obstacle avoidance based on Dubins curve and tentacle algorithm. In: SAE Technical Paper. SAE International (September 2017). https://doi.org/10.4271/2017-01-1951

  19. Yoon, H., Chou, Y., Chen, X., Frew, E., Sankaranarayanan, S.: Predictive runtime monitoring for linear stochastic systems and applications to geofence enforcement for UAVs. In: Finkbeiner, B., Mariani, L. (eds.) RV 2019. LNCS, vol. 11757, pp. 349–367. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-32079-9_20

    Chapter  Google Scholar 

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Acknowledgements

This work was supported by the US Air Force Research Laboratory’s Strategic Development Planning and Experimentation Office under contract number HQ0034-19-D-0006. The authors would also like to thank Dr.’s Christopher Eaton, Edward White, and Reed Young for their leadership and fostering of this work. Additionally, we thank the entire team, especially Dorothy Kirlew and Andrea Jensenius, for their dedication in making the flight-testing of this approach possible.

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Correspondence to Aurora Schmidt .

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Kouskoulas, Y., Wu, R., Brulé, J., Genin, D., Schmidt, A., Machado, T.J. (2021). Good Fences Make Good Neighbors. In: Dutle, A., Moscato, M.M., Titolo, L., Muñoz, C.A., Perez, I. (eds) NASA Formal Methods. NFM 2021. Lecture Notes in Computer Science(), vol 12673. Springer, Cham. https://doi.org/10.1007/978-3-030-76384-8_14

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  • DOI: https://doi.org/10.1007/978-3-030-76384-8_14

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