image: The entire landing process is divided into a tracking phase and a landing phase. During the tracking phase, the UAV is maneuvered to maintain at a close distance above the ship while predicting the ship’s roll and pitch motion online. The landing phase is initiated when an appropriate QP is identified.
Credit: Chinese Journal of Aeronautics
Recently, a research team led by Tao Song from Beijing Institute of Technology, China proposed a flight envelope constrained fixed-time control strategy to achieve a reliable UAV landing on a maneuvering ship. This work well balances the control requirements between precise landing position and safe landing attitude, ensuring both the steady-state performance and the transient behavior of the tracking error.
The team published their work in Chinese Journal of Aeronautics (Volume 38, Issue 8, August 2025).
“Quadrotor UAV is a typical underactuated system, making it difficult to simultaneously track the dynamic motion of a ship in all six degrees of freedom. To address this challenge, we developed a landing control strategy based on ship motion prediction. Specifically, a Sliding Data Window Auto-Regressive (SDW-AR) model was designed to predict the ship’s roll and pitch motions in real time, and then identify the Quiescent Period (QP) required for the UAV to land safely according to the prediction results. Unlike conventional fixed-structure forecast models, the SDW-AR model employs a variable-structure design. The model parameters are updated online according to the latest observed data, thus enhances prediction accuracy by adapting to recent data trends.”, said Tao Song, the corresponding author of the paper, a professor in the School of Aerospace Engineering at Beijing Institute of Technology.
The researchers designed a Barrier Function-based Non-Singular Terminal Sliding Mode Controller (BFNTSMC), which not only guarantees tracking error steady-state convergence within an identified QP, but also improves the transient performance without violating the flight envelope constraints, thus effectively suppressing the control overshoot during the touchdown phase and minimizing the risk of collision. In addition, a Fixed-Time Disturbance Observer (FxTDO) was integrated into the BFNTSMC for estimating and compensating lumped disturbances, further enhancing the disturbance rejection capability.
Since the accessibility of GNSS signal is subject to satellite coverage limitations, obstructions from the ship’s superstructure, jamming, and spoofing, Prof. Song further suggested that future work would focus on vision-based shipboard landing and on extending the proposed strategy to GNS-denied environments.
Original Source
Cheng ZHANG, Tao SONG, Hong TAO, Tao JIANG. Flight envelope constrained UAV shipboard landing control within an identified quiescent period[J]. Chinese Journal of Aeronautics, 2025, 38(8): 103463. https://doi.org/10.1016/j.cja.2025.103463.
About Chinese Journal of Aeronautics
Chinese Journal of Aeronautics (CJA) is an open access, peer-reviewed international journal covering all aspects of aerospace engineering, monthly published by Elsevier. The Journal reports the scientific and technological achievements and frontiers in aeronautic engineering and astronautic engineering, in both theory and practice. CJA is indexed in SCI (IF = 5.7, Q1), EI, IAA, AJ, CSA, Scopus.
Journal
Chinese Journal of Aeronautics
Article Title
Flight envelope constrained UAV shipboard landing control within an identified quiescent period
Article Publication Date
7-Mar-2025