Trajectory re-planning method for elliptical rescue orbit under rocket thrust drop fault

Abstract

The invention discloses a trajectory re-planning method for an elliptical rescue orbit under rocket thrust drop faults. The trajectory re-planning method comprises the following steps: constructing trajectory optimization problems of an elliptical rescue orbit under various thrust drop faults; adopting an adaptive pseudo-spectral method to solve the trajectory optimization problem of the elliptical rescue orbit in an off-line mode so as to obtain a sample set of fault state-orbit injection parameters; performing normalization processing on the sample data by adopting a maximum-minimum method, selecting a radial basis function neural network data center through an orthogonal least square method, and training the radial basis function neural network in an off-line manner so as to establish a nonlinear mapping relation from a fault state to an orbit injection parameter, wherein theradial basis function is a Gaussian basis function; and solving an optimal propellant optimization problem on line by adopting a self-adaptive pseudo-spectral method to obtain a flight trajectory. According to the invention, the orbit injection parameters are decided through the radial basis function neural network, a reasonable initial value is provided for trajectory planning of the online elliptical rescue orbit, and the situation that the calculation efficiency is reduced due to conflicts among variables in the target function can be avoided.

Description

technical field [0001] The invention relates to the technical field of launch vehicle rescue under failure, in particular to a trajectory re-planning method for an elliptical rescue orbit under a rocket thrust drop failure. Background technique [0002] As a rocket power device, the engine is the decisive factor for the flight reliability and safety of the rocket. In actual flight missions, the failure of the launch vehicle engine and other reasons will easily cause the thrust to drop. If the guidance and control scheme under the nominal ballistic condition is continued to be used, it will be difficult to complete the mission, which will lead to the failure of the mission. [0003] Generally, the trajectory optimization problem is described as an optimal control problem, and the adaptive pseudospectral method is widely used in the traditional solution method. However, there are some deficiencies in solving the online trajectory optimization problem for thrust descent faults...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the shortcomings of the adaptive pseudo-spectral method in the online trajectory re-planning of the thrust drop fault, which takes a long time or does not converge, the present invention provides a trajectory re-planning method, which provides a reasonable initial value for the trajectory planning of the online elliptical rescue track, and It can avoid the reduction of computational efficiency caused by the conflict between variables in the objective function

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