Research On Iterative Learning Control For Multi-point Excitation Of Heavy Rocket Modal Test

For further structural analysis of rockets,it is necessary to develop a modal testing and analysis system with better performance.More excitation points need to be distributed to obtain better results from the test for the modal analysis of the large structure such as the heavy-lift rocket.This paper studies the control of the multi-exciter fixed-frequency sine vibration required in the modal testing and analysis system.The modal test system consists the excitation system,sensors,and the structure.And there is a strong coupling between the excitation system and the structure,so the signal of each channel will be coupled by the structure under test,which brings the challenge of the excitation force control issues.In this paper,the feasible control method is studied to control the sinusoidal excitation force of 32 channels.First,this paper reviews some relevant domestic and foreign research.Then,a model of the coupled system is established.After that,the PID type iterative learning control method and the real domain iterative learning control method are studied.With the help of MATLAB simulation tool,the control method has been simulated and verified.The modal testing and analysis is needed in various fields,so the iterative control method of multi-point excitation of heavy rocket modal test,which studied in this paper,can also be used as a general control method in the modal testing and analysis system for the multi-exciter fixed-frequency sine vibration in other fields.