Synthetic Analysis on Radar Cross-Section and Remote Sensing for an Ornithopter

Bio-Robotics

Research article

Synthetic Analysis on Radar Cross-Section and Remote Sensing for an Ornithopter

Zhou, Z., & Huang, J. (2025). Synthetic Analysis on Radar Cross-Section and Remote Sensing for an Ornithopter. Bio-Robotics, 1(1), 32–53. https://doi.org/10.54963/br.v1i1.1363

Authors

  • Zeyang Zhou

    School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, China
  • Jun Huang

    School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, China

Received: 13 April 2025; Revised: 28 May 2025; Accepted: 5 June 2025; Published: 11 June 2025

To learn remote sensing features and radar cross-section (RCS) of a biorobotics ornithopter, a conjoint analysis approach built on remote sensing imaging and dynamic electromagnetic scattering is presented. The fuselage model of this flapping-wing aircraft adopts a low-scattering configuration design, with a pair of wings located on both sides of the front fuselage. High-fidelity unstructured mesh technology is utilized to model the surfaces of wings and fuselage. Linear transformation is employed in analyzing remote sensing grayscale, and dynamic electromagnetic scattering methods are applied to obtain the RCS of objects. The results show that this method can acquire the remote sensing grayscale characteristics of the ground and the ornithopter; however, the presence of some ground objects makes it difficult for flapping-wing machines to be identified. Compared to the forward case, there are more azimuths in the lateral direction, which are beneficial in reducing the average and peak indicators of the dynamic RCS of the ornithopter. Considering the case of tail incidence, the peak and mean RCS of the ornithopter show a tendency to first decrease and then grow within a given range. Low-grayscale water bodies and boundary areas with significant grayscale differences are advantageous for quickly identifying the ornithopter.

Keywords:

Remote Sensing Modeling Dynamic Electromagnetic Scattering Flapping Wing Joint Analysis Radar Stealth

References

  1. Bevidran, N. Swarm Robotics in Agriculture: Collective Behaviour for Precision Farming. Bio-Robotics 2025, 1, 55–69.
  2. Xiao, S.; Hu, K.; Huang, B.; et al. A Review of Research on the Mechanical Design of Hoverable Flapping Wing Micro-Air Vehicles. J. Bionic Eng. 2021, 18, 1235–1254.
  3. Bluman, J.E.; Pohly, J.A.; Sridhar, M.K.; et al. Achieving Bioinspired Flapping Wing Hovering Flight Solutions on Mars via Wing Scaling. Bioinsp. Biomim. 2018, 13, 046010.
  4. Fu, Y.; Zhao, S. Design of the Aircraft Model for Bionic Dragonflies’ Flapping Wings and Analysis on the Aerodynamic Characteristics. J. Mach. Des. 2021, 38, 79–87.
  5. Shyy, W.; Aono, H.; Chimakurthi, S.K.; et al. Recent Progress in Flapping Wing Aerodynamics and Aeroelasticity. Prog. Aerosp. Sci. 2010, 46, 284–327.
  6. Kumar, A.; Kumar, N.; Das, R.; et al. In Vivo Structural Dynamic Analysis of the Dragonfly Wing: The Effect of Stigma as Its Modulator. Philos. Trans. R. Soc. A 2019, 377, 20190132.
  7. Jiao, Z.; Wang, L.; Zhao, L.; et al. Hover Flight Control of X-Shaped Flapping Wing Aircraft Considering Wing–Tail Interactions. Aerosp. Sci. Technol. 2021, 116, 106870.
  8. Peng, C.; Sun, L.; Wang, Y.; et al. Control Oriented Longitudinal Modeling and Analysis of Pigeon-Like Flapping-Wing Aircraft. J. Beijing Univ. Aeronaut. Astronaut. 2021, 48, 2510–2519.
  9. Bie, D.; Li, D.; Xiang, J.; et al. Design, Aerodynamic Analysis and Test Flight of a Bat-Inspired Tailless Flapping Wing Unmanned Aerial Vehicle. Aerosp. Sci. Technol. 2021, 112, 106557.
  10. Zhong, Y.; Wu, J.; Lin, Z.; et al. Design of a Two-Stage Flapping Wing Bionic Aircraft. Electromech. Eng. Technol. 2021, 50, 9–12. (in Chinese)
  11. Zhou, Z.; Huang, J. Numerical Investigations on Radar Cross-Section of Helicopter Rotor with Varying Blade Pitch. Aerosp. Sci. Technol. 2022, 123, 107452.
  12. Shen, H.; Yu, Y. Development and Key Technologies of Morphological Bionic Aircraft. Adv. Aeronaut. Sci. Eng. 2021, 12, 9–19. (in Chinese)
  13. Zhou, Z.; Huang, J. X-Band Radar Cross-Section of Tandem Helicopter Based on Dynamic Analysis Approach. Sensors 2021, 21, 271.
  14. Knott, E. RCS Reduction of Dihedral Corners. IEEE Trans. Antennas Propag. 1977, 25, 406–409.
  15. Jiang, Z.H. Research on Radar Target Characteristics of Unmanned Helicopter. J. Astronaut. Metrol. Meas. 2015, 35, 61–66.
  16. Maffett, A.L. Topics for a Statistical Description of Radar Cross Section. Wiley-Interscience: New York, NY, USA, 1989.
  17. Ye, S.B.; Xiong, J.J. Dynamic RCS Behavior of Helicopter Rotating Blades. Acta Aeronaut. Astronaut. Sin. 2006, 27, 816–822.
  18. Zhou, Z.; Huang, J.; Wang, J. Compound Helicopter Multi-Rotor Dynamic Radar Cross Section Response Analysis. Aerosp. Sci. Technol. 2020, 105, 106047.
  19. Nguyen, K.; Au, L.T.K.; Phan, H.V.; et al. Effects of Wing Kinematics, Corrugation, and Clap-and-Fling on Aerodynamic Efficiency of a Hovering Insect-Inspired Flapping-Wing Micro Air Vehicle. Aerosp. Sci. Technol. 2021, 118, 106990.
  20. Zhou, Z.; Huang, J. Study of RCS Characteristics of Tilt-Rotor Aircraft Based on Dynamic Calculation Approach. Chin. J. Aeronaut. 2022, 34, 426–437.
  21. Guo, J.; Yin, H.C.; Ye, S.J.; et al. Novel Technology for Electromagnetic Characteristic Simulation of Helicopter Blades. Acta Aeronaut. Astronaut. Sin. 2019, 40, 322732.
  22. Zhou, Z.; Huang, J. An Optimization Model of Parameter Matching for Aircraft Catapult Launch. Chin. J. Aeronaut. 2020, 33, 191–204.
  23. Ruiz, C.; Acosta, J.Á.; Ollero, A. Aerodynamic Reduced-Order Volterra Model of an Ornithopter under High-Amplitude Flapping. Aerosp. Sci. Technol. 2022, 121, 107331.
  24. Takahashi, T. A Fast Time-Domain Boundary Element Method for Three-Dimensional Electromagnetic Scattering Problems. J. Comput. Phys. 2023, 482, 112053.
  25. Abbasi, S.H.; Mahmood, A.; Khaliq, A. Bioinspired Feathered Flapping Wing UAV Design for Operation in Gusty Environment. J. Robot. 2021, 2021, 8923599.
  26. Ma, Y.; Karpuk, S.; Elham, A. Conceptual Design and Comparative Study of Strut-Braced Wing and Twin-Fuselage Aircraft Configurations with Ultra-High Aspect Ratio Wings. Aerosp. Sci. Technol. 2022, 121, 107395.
  27. Zhou, Z.; Huang, J. Utilizing Dynamic Scattering for Learning Radar Cross-Section of a Flapping-Wing Aircraft. Photonics 2022, 9, 877.
  28. Quintana, A.; Graves, G.; Hassanalian, M.; et al. Aerodynamic Analysis and Structural Integrity for Optimal Performance of Sweeping and Spanning Morphing Unmanned Air Vehicles. Aerosp. Sci. Technol. 2021, 110, 106458.
  29. Ammari, H.; Bao, G.; Wood, A. A Cavity Problem for Maxwell’s Equations. Methods Appl. Anal. 2002, 9, 249–260.
  30. Lee, J.; Yoon, S.H.; Kim, C. Experimental Surrogate-Based Design Optimization of Wing Geometry and Structure for Flapping Wing Micro Air Vehicles. Aerosp. Sci. Technol. 2022, 123, 107451.
  31. Singh, S.; Zuber, M.; Hamidon, M.N.; et al. Classification of Actuation Mechanism Designs with Structural Block Diagrams for Flapping-Wing Drones: A Comprehensive Review. Prog. Aerosp. Sci. 2022, 132, 100833.
  32. Zhou, Z.; Huang, J. Study of the Radar Cross-Section of Turbofan Engine with Biaxial Multirotor Based on Dynamic Scattering Method. Energies 2020, 13, 5802.
  33. Zhou, Z.; Huang, J. Y-Type Quadrotor Radar Cross-Section Analysis. Aircr. Eng. Aerosp. Technol. 2023, 95, 535–545.
  34. Silva, R.C.; Bueno, D.D. On the Dynamics of Flexible Wings for Designing a Flapping-Wing UAV. Drones 2024, 8, 56.
  35. Zhou, Z.; Huang, J. Z-Folding Aircraft Electromagnetic Scattering Analysis Based on Hybrid Grid Matrix Transformation. Sci. Rep. 2022, 12, 4452.
  36. Xue, Y.; Cai, X.; Liu, H. Aerodynamics and Stability of Hawkmoth Forward Flight with Flexible Wing Hinge. Phys. Rev. Fluids 2024, 9, 063101.