Abstract: Based on the experimental data parameter identification method, dynamic models of the propulsion system components of flapping wing vehicles, including brushless DC motors, Electronic Speed Controller (ESC), lithium batteries and the flapping mechanism, are established to rapidly evaluate the endurance of the flapping wing air vehicle, facilitate the design and optimization of the propulsion system for different flapping wings, gradually reduce physical verification and test flights, and speed up the development of the flapping wing air vehicle. Among these models, the relative error of the motor model is smaller than 10% and that of the lithium battery dynamic model smaller than 6%. A semi-empirical high-precision modeling method for the instantaneous aerodynamic load of the flapping shaft is proposed based on the aerodynamic data and power data of the wind tunnel experimental data, solving the aerodynamic load measurement problem with the coefficient of determination larger than 0.89. The flapping wing vehicle simulation system, which integrates the above models, also includes a cycle-averaged aerodynamic model of the flapping wing, an aerodynamic model of the horizontal tail and a longitudinal control model to ensure that the simulation was conducted in a trim state. This system can be used for full mission profile endurance simulation, with the error between endurance simulation and the test flight results smaller than 3%. Adopting the modular method, the integrated flapping wing air vehicle simulation system enables independent adjustment of the parameters in each model, providing further application to the research on multi-disciplinary optimization of the flapping wing air vehicle.

Key words: flapping wing vehicles, modeling of propulsion system, modeling of flapping wing, simulation systems, endurance simulation