SO(2)-Equivariant Downwash Models for Close Proximity Flight (2305.18983v3)
Abstract: Multirotors flying in close proximity induce aerodynamic wake effects on each other through propeller downwash. Conventional methods have fallen short of providing adequate 3D force-based models that can be incorporated into robust control paradigms for deploying dense formations. Thus, learning a model for these downwash patterns presents an attractive solution. In this paper, we present a novel learning-based approach for modelling the downwash forces that exploits the latent geometries (i.e. symmetries) present in the problem. We demonstrate that when trained with only 5 minutes of real-world flight data, our geometry-aware model outperforms state-of-the-art baseline models trained with more than 15 minutes of data. In dense real-world flights with two vehicles, deploying our model online improves 3D trajectory tracking by nearly 36% on average (and vertical tracking by 56%).
- J. A. Preiss, W. Honig, G. S. Sukhatme, and N. Ayanian, “Crazyswarm: A large nano-quadcopter swarm,” in IEEE International Conference on Robotics and Automation, 2017, pp. 3299–3304.
- G. Vásárhelyi, C. Virágh, G. Somorjai, T. Nepusz, A. E. Eiben, and T. Vicsek, “Optimized flocking of autonomous drones in confined environments,” Science Robotics, vol. 3, no. 20, p. eaat3536, 2018.
- M. Turpin, N. Michael, and V. Kumar, “Trajectory design and control for aggressive formation flight with quadrotors,” Autonomous Robots, vol. 33, pp. 143–156, 2012.
- A. Shankar, S. Elbaum, and C. Detweiler, “Dynamic path generation for multirotor aerial docking in forward flight,” in IEEE Conference on Decision and Control, 2020, pp. 1564–1571.
- R. Miyazaki, R. Jiang, H. Paul, K. Ono, and K. Shimonomura, “Airborne docking for multi-rotor aerial manipulations,” in IEEE/RSJ International Conference on Intelligent Robots and Systems, 2018, pp. 4708–4714.
- A. Shankar, S. Elbaum, and C. Detweiler, “Multirotor docking with an airborne platform,” in Experimental Robotics: The 17th International Symposium. Springer, 2021, pp. 47–59.
- S. Yoon, P. V. Diaz, D. D. Boyd Jr, W. M. Chan, and C. R. Theodore, “Computational aerodynamic modeling of small quadcopter vehicles,” in American Helicopter Society (AHS) 73rd Annual Forum, 2017.
- S. Yoon, H. C. Lee, and T. H. Pulliam, “Computational analysis of multi-rotor flows,” in AIAA Aerospace Sciences Meeting, 2016, p. 0812.
- S.-J. Chung, A. A. Paranjape, P. Dames, S. Shen, and V. Kumar, “A survey on aerial swarm robotics,” IEEE Transactions on Robotics, vol. 34, no. 4, pp. 837–855, 2018.
- X. Zhou, J. Zhu, H. Zhou, C. Xu, and F. Gao, “Ego-swarm: A fully autonomous and decentralized quadrotor swarm system in cluttered environments,” in IEEE International Conference on Robotics and Automation, 2021, pp. 4101–4107.
- G. Throneberry, C. Hocut, and A. Abdelkefi, “Multi-rotor wake propagation and flow development modeling: A review,” Progress in Aerospace Sciences, vol. 127, p. 100762, 2021.
- H. Zhang, Y. Lan, N. Shen, J. Wu, T. Wang, J. Han, and S. Wen, “Numerical analysis of downwash flow field from quad-rotor unmanned aerial vehicles,” International Journal of Precision Agricultural Aviation, vol. 3, no. 4, 2020.
- G. Shi, X. Shi, M. O’Connell, R. Yu, K. Azizzadenesheli, A. Anandkumar, Y. Yue, and S.-J. Chung, “Neural lander: Stable drone landing control using learned dynamics,” in IEEE International Conference on Robotics and Automation, 2019, pp. 9784–9790.
- G. Shi, W. Hönig, X. Shi, Y. Yue, and S.-J. Chung, “Neural-swarm2: Planning and control of heterogeneous multirotor swarms using learned interactions,” IEEE Transactions on Robotics, vol. 38, no. 2, pp. 1063–1079, 2021.
- G. Shi, W. Hönig, Y. Yue, and S.-J. Chung, “Neural-swarm: Decentralized close-proximity multirotor control using learned interactions,” in IEEE International Conference on Robotics and Automation, 2020, pp. 3241–3247.
- J. Li, L. Han, H. Yu, Y. Lin, Q. Li, and Z. Ren, “Nonlinear mpc for quadrotors in close-proximity flight with neural network downwash prediction,” arXiv preprint arXiv:2304.07794, 2023.
- L. Wang, E. A. Theodorou, and M. Egerstedt, “Safe learning of quadrotor dynamics using barrier certificates,” in IEEE International Conference on Robotics and Automation, 2018, pp. 2460–2465.
- N. Mohajerin, M. Mozifian, and S. Waslander, “Deep learning a quadrotor dynamic model for multi-step prediction,” in IEEE International Conference on Robotics and Automation, 2018, pp. 2454–2459.
- R. T. Chen, Y. Rubanova, J. Bettencourt, and D. K. Duvenaud, “Neural ordinary differential equations,” Advances in Neural Information Processing Systems, vol. 31, 2018.
- K. Y. Chee, T. Z. Jiahao, and M. A. Hsieh, “Knode-mpc: A knowledge-based data-driven predictive control framework for aerial robots,” IEEE Robotics and Automation Letters, vol. 7, pp. 2819–2826, 2022.
- M. M. Bronstein, J. Bruna, T. Cohen, and P. Veličković, “Geometric deep learning: Grids, groups, graphs, geodesics, and gauges,” arXiv preprint arXiv:2104.13478, 2021.
- C. Esteves, “Theoretical aspects of group equivariant neural networks,” arXiv preprint arXiv:2004.05154, 2020.
- D. Wang, J. Y. Park, N. Sortur, L. L. Wong, R. Walters, and R. Platt, “The surprising effectiveness of equivariant models in domains with latent symmetry,” in International Conference on Learning Representations, 2023.
- D. Wang, R. Walters, X. Zhu, and R. Platt, “Equivariant q𝑞qitalic_q learning in spatial action spaces,” in Conference on Robot Learning. PMLR, 2022, pp. 1713–1723.
- B. Yu and T. Lee, “Equivariant reinforcement learning for quadrotor uav,” in IEEE American Control Conference, 2023, pp. 2842–2847.
- X. Zhu, D. Wang, O. Biza, G. Su, R. Walters, and R. Platt, “Sample efficient grasp learning using equivariant models,” Proceedings of Robotics: Science and Systems, 2022.
- D. Wang, M. Jia, X. Zhu, R. Walters, and R. Platt, “On-robot learning with equivariant models,” in Conference on Robot Learning, 2022.
- P. J. Gorder and R. A. Hess, “Sequential loop closure in design of a robust rotorcraft flight control system,” Journal of Guidance, Control, and Dynamics, vol. 20, no. 6, pp. 1235–1240, 1997.
- A. Shankar, S. Elbaum, and C. Detweiler, “Freyja: A full multirotor system for agile & precise outdoor flights,” in IEEE International Conference on Robotics and Automation, 2021, pp. 217–223.