A Rescue Orbit Decision Method Based on RBFNN under Rocket Thrust Decline Failure

Abstract

The invention discloses an RBFNN-based rescue orbit decision-making method under a rocket thrust drop failure, which includes: establishing a second-level flight dynamics equation of the rocket's ascent section in the geocentric inertial coordinate system, and constructing a series of circular orbit semi-circular orbits under a thrust drop failure The maximum optimization problem of the long axis; the maximum optimization problem of the semi-major axis of the circular orbit is solved offline by the adaptive pseudospectral method, and the maximum and minimum method is used to normalize the sample data of the optimal rescue track in the fault state, and all the data are normalized to [‑1 ,1], using the orthogonal least squares method to select the radial basis neural network RBFNN data center, in which the radial basis function chooses the Gaussian function, and trains the radial basis neural network offline, so as to establish the fault state to the optimal rescue track Linear mapping relationship; the radial basis neural network is migrated to the actual flight of the rocket, and the fault state of the flight is used as input, and the radial basis neural network decides the rescue trajectory online.

Description

technical field [0001] The invention relates to the technical field of rescue of launch vehicles under failure, in particular to a RBFNN-based rescue orbit decision-making method under the failure of rocket thrust drop. Background technique [0002] As a rocket power device, the engine is the decisive factor for the reliability and safety of the whole rocket flight, and its reliability is related to the success or failure of the entire flight mission. In the actual flight mission, the failure of the launch vehicle engine can easily cause the thrust to drop. If the guidance and control scheme under the nominal ballistic condition is continued, it will be difficult to complete the mission. In order to actively avoid the fall of the payload, it is necessary to re-plan the rescue trajectory and flight trajectory online according to the fault state, so that the payload can enter the rescue orbit. [0003] At present, for the problem of online rescue under thrust drop failure, th...

AI Technical Summary

Problems solved by technology

The above method couples the two problems of rescue orbit decision-making and flight trajectory to optimize together. Since the rescue orbit is unknown, the search space for the optimal solution is large, which affects the calculation efficiency of the online part.

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