A Nonlinear Model and Parameter Identification Method for Rubber Isolators under Shock Excitation in Underwater Vehicles

Journal of Marine Science and Engineering

Jie Zhou¹  Chizhen Xu¹  Peixun Yu¹  Junqiang Bai²  Heye Xiao²  Ruobing Wang³ 

[1] School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China;Unmanned System Research Institute, Northwestern Polytechnical University, Xi’an 710072, China;Xi’an Modern Control Technology Research Institute, Xi’an 710065, China;

关键词: rubber isolator;    nonlinear behavior;    parameter identification method;    multilayer feed-forward neural network;    fractional-order method;    underwater vehicle;   

DOI  :  10.3390/jmse9111282

来源: DOAJ

【 摘 要 】

Rubber isolators are usually used to protect high-precision equipment of autonomous underwater vehicles (AUVs), avoiding damage from overlarge dynamic excitation. Considering the nonlinear properties of the rubber material, the nonlinear behavior of rubber isolators under shock exaltation is hard to be predict accurately without the available modal and accurate parameters. In view of this, the present study proposes a nonlinear model and parameter identification method of rubber isolators to present their transient responses under shock excitation. First, a nonlinear model of rubber isolators is introduced for simulating their amplitude and frequency-dependent deformation under shock excitation. A corresponding dynamic equation of the isolation system is proposed and analytically solved by the Newmark method and the Newton-arithmetic mean method. Secondly, a multilayer feed-forward neural network (MFFNN) is constructed with the current model to search the parameters, in which the differences between the estimated and tested responses are minimized. The sine-sweep and drop test are planned with MFFNN to build the parameter identification process of rubber isolators. Then, a T-shaped isolator composed of high-damping silicon rubber is selected as a sample, and its parameters were determined by the current identification process. The transient responses of the isolation system are reconstructed by the current mode with the identified parameter, which show good agreement with measured responses. The accuracy of the proposed model and parameter identification method is proved. Finally, the errors between the reconstructed responses and tested responses are analyzed, and the main mode of energy attenuation in the rubber isolator is discussed in order to provide an inside view of the current model.

【 授权许可】

Unknown