An efficient method for trimming the flight dynamics model of fixed-wing aircraft

Abstract

The invention belongs to the technical field of aircraft design, and in particular relates to an efficient method for trimming a flight dynamics model of a fixed-wing aircraft. The accuracy of the trim calculation is given according to the design calculation requirements. Accuracy is compared, if the calculated value meets the accuracy requirement, the trim calculation is ended, and the angle of attack, elevator deflection angle and throttle opening calculated in this step are used as the trim result; if the calculated value does not meet the accuracy requirement, the iterative calculation is continued, Until the accuracy requirements are met or it is judged during the calculation that the given state point is outside the flight envelope. The invention has the characteristics of fast global convergence, low requirements on the initial value, simple algorithm, and easy grasp and program realization. The calculation process does not require the calculation of complex dynamics and kinematics equations, which reduces the amount of iterative calculations and improves the trimming efficiency. All parameters in the trim calculation are calculated in dimensionless form, which improves the accuracy of the trim results.

Description

technical field [0001] The invention belongs to the technical field of aircraft design, and in particular relates to an efficient method for trimming a flight dynamics model of a fixed-wing aircraft. Background technique [0002] In the field of aircraft overall performance design and flight control law design, the trimming of flight dynamics model is the basis of each design content, and the correctness of trimming results and the accuracy of trimming have an important impact on aircraft design. [0003] For fixed-wing aircraft, the overall performance design of the aircraft, such as the design or calculation of the flight envelope, cruising altitude, range, flight time, and mission planning, is based on the trim calculation of the dynamic model; In the process of control law design, tasks such as cruise performance analysis, stability analysis, control structure design, control parameter tuning, time-frequency domain analysis, and robustness analysis are closely related to...

AI Technical Summary

Problems solved by technology

The advantage of genetic algorithm is that it has global convergence characteristics, strong group search ability, and fast initial optimization speed, but genetic algorithm still has the defects of slow subsequent optimization speed and low precision.

[0007] Combining the advantages of Newton's method and genetic algorithm, some scholars have studied a hybrid genetic algorithm with global fast convergence characteristics. This algorithm realizes the combination of the advantages of traditional numerical calculation methods and modern intelligent calculation methods, but still cannot avoid complex The solution process of nonlinear equations, and in practical applications, practitioners in the field of aircraft design are required to master certain modern intelligent calculation methods. The combination of the two algorithms makes the algorithm complex and difficult to understand and program.

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