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Autonomous omnidirectional reentry guidance method based on linear pseudospectral model predictive control

A model predictive control and linear pseudospectral technology, which is applied in attitude control, space navigation equipment, space navigation aircraft, etc., can solve problems such as low computational efficiency and poor robustness

Active Publication Date: 2020-06-23
BEIHANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Subsequently, many engineers and scientists have devoted themselves to improving the performance of reference tracking algorithms; these efforts include simplifying planning methods, improving planning accuracy, and studying various tracking laws, but reference tracking algorithms need task-dependent adjustments, poor robustness, and computational efficiency Low

Method used

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  • Autonomous omnidirectional reentry guidance method based on linear pseudospectral model predictive control
  • Autonomous omnidirectional reentry guidance method based on linear pseudospectral model predictive control
  • Autonomous omnidirectional reentry guidance method based on linear pseudospectral model predictive control

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Experimental program
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Embodiment 1

[0104] The method of autonomous omnidirectional reentry guidance based on linear pseudospectral model predictive control, the specific steps are as follows:

[0105] S1 initialization: set initial reentry parameters, terminal constraints, and set appropriate initial control parameters through offline ballistic optimization.

[0106] That is, initial modeling, as follows:

[0107] S11 Reentry Kinetic Equation

[0108] Based on the spherical assumption and considering the rotation of the earth, the three-degree-of-freedom motion equation of the unpowered gliding vehicle can be described as the following form

[0109]

[0110]

[0111]

[0112]

[0113] Among them, r represents the distance from the center of mass of the aircraft to the center of the earth, θ and φ represent the longitude and latitude respectively, v represents the velocity of the aircraft relative to the earth, and γ represents the angle between the velocity vector of the aircraft relative to the ea...

Embodiment 2

[0332] In this embodiment, ten groups of calculation examples with different target points will be used to evaluate the performance of the method proposed in the present invention. The initial conditions of these ten groups of calculation examples are the same except for the heading angle, and the handover conditions of the terminal and the energy management section are also the same, as shown in Table 1 and Table 2, respectively. The terminal position constraints of the ten groups of calculation examples are shown in Table 3. It should be noted that when the remaining range satisfies the cut-off condition, the simulation ends. All simulation results as Figure 2 to Figure 10 shown.

[0333] Table 1 Initial reentry conditions

[0334]

[0335] Table 2 Shift conditions of terminal energy management section

[0336]

[0337] Table 3 Terminal position constraints of different calculation examples

[0338]

[0339] figure 2 The trajectories on the ground of ten gro...

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Abstract

The invention discloses an autonomous full-range reentry guidance method based on linear pseudospectral model predictive control. When a reduced-order dynamic equation is established, an energy E is chosen as an independent variable and a smooth gliding condition is introduced, six sets of motion equations are compressed into three sets of equations, and the influence of the rotation of the earthon the reduced-order dynamic equation is fully considered; therefore, not only can the coupled motion on the latitude and longitude direction be dealt with, but also a high-precision solution considering the rotation of the earth is obtained through the technical processing of a centripetal force and a Coriolis force. In addition, proportional guidance and polynomial guidance acting on an assumption of spherical earth are designed separately; and various terminal constraints in the respective planes are guaranteed in the vertical and horizontal directions separately after the last inversion. Simulation results show that the algorithm not only has fast computational efficiency, but also has high computational accuracy, which can provide stable and robust reentry guidance performance even inharsh reentry environments.

Description

technical field [0001] The invention relates to the field of re-entry guidance, and more specifically relates to an autonomous all-firing re-entry guidance method based on linear pseudospectral model predictive control. Background technique [0002] Since the launch of the "Apollo Program" and "Space Shuttle Program", re-entry guidance has received extensive attention in the past 50 years, and a large number of re-entry guidance algorithms have emerged. While specific algorithms vary according to the mission and type of vehicle, those reentry guidance algorithms essentially fall into two broad categories: traditional reference-tracking algorithms and more recently developed predictive-correction algorithms. There is no doubt that the space shuttle guidance is the most representative reference tracking algorithm in the world, and has been successfully verified by more than 100 launch missions. The reference tracking algorithm consists of three parts: the first part is to pre...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G05D1/08
CPCB64G1/244
Inventor 杨良陈万春杜文豪
Owner BEIHANG UNIV