Precision Control of UAVs under Small-Scale Coaxial Rotor Aerodynamic Interference Using TTV-UDE

Small-scale coaxial rotor unmanned aerial vehicles (UAVs) suffer from strong aerodynamic interference between rotors, which challenges precise attitude and position control. To address this, a theoretical model of aerodynamic interference is developed, revealing the dynamic relationship between interference thrust and additional thrust. Using this model to define trigger conditions, a time-varying robust control algorithm with an integrated trigger mechanism (TTV-UDE) is designed, enabling adaptive estimation of uncertainties and disturbances. This approach identifies maneuvering intention from the mismatch between the UAV’s dynamic model and actual behavior, thereby enhancing resistance to aerodynamic interference and external disturbances. Simulations and flight experiments demonstrate rapid early-stage convergence, reduced initial error accumulation, and sustained accuracy and stability over long-term operation. The TTV-UDE reduces altitude root mean square and lateral errors, achieving fast transient suppression and minimal steady-state oscillations, and thus provides an effective and reliable solution for high-precision UAV trajectory tracking in complex environments.