Modeling method for aircraft longitudinal phase plane directly based on three-dimensional model

Abstract

The invention provides a modeling method for an aircraft longitudinal phase plane directly based on a three-dimensional model. The built model performs equivalent transformation directly based on an aircraft three-dimensional motion model, and avoids incorrect direct approximate cuased by the aerodynamical moment effect, the lateral-directional influence and the like ignored in an aerodynamic force equation; an equivalent second-order differential equation set is obtained through a three-dimensional aircraft motion equation and aerodynamic force and aerodynamical moment models obtained through experiments; the equation set expresses a system stability model, can directly adopt a phase plane analytical method to perform theoretical analysis, or adopts an Ode45 module and the like in MATLAB (matrix laboratory) to dreictly perform numerical analysis; more non-linear phenomena and unstable factors and unsafe factors of the system can be found out; and problems of unstable and unsafe flight and the like are reduced or even avoided.

Description

technical field [0001] The invention relates to an aircraft phase plane analysis equivalent model modeling method, in particular to an aircraft longitudinal phase plane modeling method directly based on a three-dimensional model. Background technique [0002] Aircraft flight at high angle of attack is an important symbol of modern and future high-performance aircraft. Taking advantage of the great resistance that the pilot receives at a high angle of attack, the pilot can flexibly control the aircraft to roll around the speed axis, so that the nose can quickly point to any direction, which can not only gain the pointing advantage to attack the enemy, but also avoid the enemy's attack and quickly Quickly turn into a counterattack to improve your own survivability. Therefore, post-stall maneuverability is one of the key factors to achieve air combat superiority, and it is also one of the main characteristics of modern and future advanced fighter jets. However, if the aircraf...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the shortcomings of the excessive approximation of the analysis model established by the existing modeling method, the present invention provides a method of modeling the longitudinal phase plane of the aircraft directly based on the three-dimensional model, and the model is directly transformed according to the equivalent transformation of the three-dimensional motion model of the aircraft, avoiding The incorrect direct approximation such as ignoring the effect of aerodynamic moment and the effect of lateral direction in the aerodynamic equation is used, and the equivalent second-order differential equations are obtained through the three-dimensional aircraft motion equation and the aerodynamic force and aerodynamic moment model obtained from the test. The equations represent After the system stability model is established, the phase plane analysis method can be directly used for theoretical analysis, or the Ode45 module in MATLAB can be used for direct numerical analysis; more nonlinear phenomena and system instability and unsafe factors can be found, and analysis can be reduced or even avoided. Problems such as instability and unsafe flight caused by the model occur

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