Abstract

Aerodynamic parameters play a decisive role in the ballistic characteristics of the projectile. How to accurately obtain the aerodynamic parameters of the projectile is an important task in the development process of the projectile. In order to further improve the identification accuracy of the projectile drag coefficient, this paper generates huge ballistic data through numerical simulation and uses the extreme learning method to identify the ballistic drag coefficient under three kinds of noise conditions. The method avoids the iterative updating process of weights and thresholds by randomly generating the input weights and threshold values of hidden layer neurons and overcomes the problem of long identification time of the traditional back propagation (BP) neural network algorithm. Based on the least squares principle, the Moore–Penrose generalized inverse matrix of the hidden layer output matrix was solved to determine the optimal output weight of the network, and then, the projectile drag coefficient was accurately identified. Comparing the extreme learning method with the traditional BP neural network method, the results show that the proposed method has higher identification accuracy and faster convergence speed and can effectively identify the projectile drag coefficient, which can meet the practical needs of engineering.

Highlights

  • There are various forms of modern war

  • The research of the aerodynamic parameter identification method can effectively improve the accuracy of the uncontrolled ejection table, reduce the design difficulty of the controlled missile guidance control system, and improve the strike accuracy

  • The traditional aerodynamic parameter identification problem of missiles based on the Champ–Kirk method and maximum likelihood method uses one trajectory to identify the aerodynamic parameters, and the identification results are different for different trajectories, which is not the real global identification

Read more

Summary

INTRODUCTION

There are various forms of modern war. As the main weapon, the ballistic performance of missiles and rockets is required to be higher. Based on the maximum likelihood criterion, Wang and co-workers used the genetic algorithm as the aerodynamic identification algorithm of missiles, which greatly reduced the complexity of aerodynamic parameter identification calculation and improved the accuracy and reliability of aerodynamic parameter identification. The extreme learning machine (ELM) is a simple and efficient neural network structure proposed by Huang from the Nanyang University of Technology in Singapore It has been widely used in cloud computing, data visualization, and random projection because of its good generalization performance, not easy to fall into local optimization, good robustness, and few parameters to be adjusted manually.. The traditional aerodynamic parameter identification problem of missiles based on the Champ–Kirk method and maximum likelihood method uses one trajectory to identify the aerodynamic parameters, and the identification results are different for different trajectories, which is not the real global identification. The identification result has the advantages of high accuracy and high speed

MATHEMATICAL MODEL
ALGORITHM PRINCIPLE OF THE EXTREME LEARNING MACHINE
Training process
Forecasting process
Data normalization
Network structure of the extreme learning machine
Input layer node number setting
Activation function selection
Setting the number of neurons in the hidden layer
Numerical simulation 1
Numerical simulation 2
Findings
CONCLUSION

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.