A new real-time guidance method for aircraft based on attitude sequence calculation

Abstract

The invention relates to the field of air vehicle guide and control system design, and provides a closed loop analytic real-time guide method; the control accuracy is high, and the speediness is good; the cruise-section guide problem of near space air vehicles can be solved under the conditions of uncertain parameters and disturbance influence; the robustness is strong. The invention adopts the technical scheme that the attitude sequence resolving-based air vehicle novel real-time guide method comprises the following steps: 1) according to the six-degrees-of-freedom equation of a near space air vehicle, providing a translational motion model, namely a translational motion equation set, and a rotational motion model, namely a rotational motion equation set; 2) simplifying the provided translational motion equation; 3) obtaining the closed loop feedback relation between the attitude angle instruction and the track, and providing an executable instruction for the control system. The invention is mainly applied to air vehicle guide and control system design.

Description

technical field [0001] The invention relates to the field of aircraft guidance and control system design and the field of near-space aircraft guidance research, and specifically relates to a novel real-time guidance method for aircraft based on attitude sequence calculation. Background technique [0002] Near space is 23 kilometers to 100 kilometers above sea level. This airspace includes the stratosphere, middle layer and part of the ionosphere. The aircraft in this airspace are called Near-space Hypersonic Vehicles (NHV). Different from traditional aerospace vehicles, near-space vehicles are immune to weather factors and most air defense weapon systems. They have high military and civilian value and can be widely used in ground observation, high-altitude reconnaissance, communication and navigation platforms, etc. . NASA (National Aeronautics and Space Administration) took the lead in proposing the concept of Near Space System (NSS: Near Space System), and its X-series ai...

AI Technical Summary

Problems solved by technology

[0003] 1. The near-space vehicle adopts a special structure designed with fuselage-engine integration, which makes the various subsystems have strong coupling and strong nonlinearity. Therefore, the mathematical model of the near-space vehicle based on the mechanism is usually very complicated. How to solve such a problem? Guidance and control system design with complex models is a difficult problem that scholars from all over the world are generally concerned about;

[0004] 2. In the large airspace and long-distance complex flight environment of near-space aircraft, there are inevitably uncertainties caused by internal structures and aerodynamic parameters, as well as interference from the external environment, which requires the integrated guidance and control system to have certain robustness

However, the neglected high-order nonlinear terms may contain important characteristics of the controlled object. The linearized model can only ensure that the method is effective in a small area near the equilibrium point. Once the system operating point deviates from this area, the LQR guidance algorithm The effectiveness of the guidance system will be greatly affected, and even lead to the instability of the guidance system

In addition, the continuous call of gain during the guidance process also makes the real-time and rapidity of the method poor

In short, most of the traditional guidance methods are designed according to the off-line trajectory, which requires a preset gain schedule and cannot guarantee real-time performance; when subjected to external interference or uncertain factors, the guidance algorithm may fail, and the robustness is poor

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