Deformation Reconstruction and High-Precision Attitude Control of a Launch Vehicle Based on Strain Measurements

Liang Zhuang,Zhang Yulin,Paolo Gasbarri

doi:10.1155/2021/6672943

Abstract

The development of launch vehicles has led to higher slenderness ratios and higher structural efficiencies, and the traditional control methods have difficulty in meeting high-quality control requirements. In this paper, an incremental dynamic inversion control method based on deformation reconstruction is proposed to achieve high-precision attitude control of slender launch vehicles. First, the deformation parameters of a flexible rocket are obtained via fiber Bragg grating (FBG) sensors. The deformation and attitude information is introduced into the incremental dynamic inverse control loop, and an attitude control framework that can alleviate bending vibration and deformation is established. The simulation results showed that the proposed method could accurately reconstruct the shapes of flexible launch vehicles with severe vibration and deformation, which could improve the accuracy and stability of attitude control.

Highlights

To improve launch capacity, the development trend of launch vehicles is to increase the slenderness ratio and reduce the structural mass; the structural vibrations and flexible characteristics of rockets are becoming increasingly significant
By installing a fiber Bragg grating sensor array on the rocket body to measure the rocket strain, the stress and deformation state of the rocket structure, decoupling attitude, and elastic deformation information can be obtained in real time to obtain accurate rocket attitude information
To address this issue and improve the accuracy of the controller, a deformation reconstruction and high-precision attitude control method of the launch vehicle based on strain measurements was proposed in this paper

Summary

Introduction

The development trend of launch vehicles is to increase the slenderness ratio and reduce the structural mass; the structural vibrations and flexible characteristics of rockets are becoming increasingly significant. Oh et al [4] proposed an attitude control method with real-time control adaptive notch filter technology and developed a demonstration system to verify the stability of the method. The research of the above scholars mainly focused on two strategies to deal with the attitude control problem caused by the vibration of the projectile: the first is to use the robustness of the controller to suppress flexible interference without using any structural filters and the second is to design a notch filter to suppress the vibration modes. By installing a fiber Bragg grating sensor array on the rocket body to measure the rocket strain, the stress and deformation state of the rocket structure, decoupling attitude, and elastic deformation information can be obtained in real time to obtain accurate rocket attitude information. An FBG+INDI control strategy is proposed, and the effectiveness and robustness of the proposed control scheme are verified

Deformation Reconstruction Method of a Flexible Launch Vehicle

Design of the High-Precision Attitude Control System

Simulation Analysis

Findings

Conclusion