Research On Design And Control Of Acoustic Source Electro-hydraulic Exciter

Acoustic source electro-hydraulic exciter is a vibration device based on electro-hydraulic servo technology,which uses the reciprocating vibration of hydraulic cylinder piston rod to excite a vibrating diaphragm to generate a desired frequency spectrum acoustic field.One of the main uses of the acoustic source electro-hydraulic exciter is to generate a high-level underwater low-frequency acoustic field with a controllable frequency spectrum to simulate the target acoustic field,and then directional interference and destruction of small underwater fast-moving targets.With the rapid development of the modern marine industry and the deployment of marine strategies,the requirements for the performance of acoustic source electro-hydraulic exciters are becoming higher and higher,so it’s meaningful to research.Due to the low system bandwidth,its own non-linear factors,the effects of external loads,and coupling to the environment,the acoustic source electro-hydraulic exciter cannot accurately reproduce the desired vibration spectrum.In order to accurately reproduce the desired frequency spectrum and accurately simulate the target acoustic field,designing the electro-hydraulic exciter of the acoustic source and studies its control strategy.The input signals of acoustic source electro-hydraulic exciter are mostly random vibration acceleration signals,and their characteristics are characterized by power spectral density(PSD).In order to accurately reproduce the 5 ～ 300 Hz reference acceleration PSD,a three-parameter servo control study was carried out to widen the system bandwidth and improve system performance.In order to make up for the shortcomings of three-parameter servo control,a research on the reproduction of random vibration power spectrum was carried out,and the input signal was iteratively modified in the frequency domain.The main research contents of this article are as follows:Chapter 1,through the analysis of the research status of electro-hydraulic exciter and its control strategies,it is found that there is a lack of high frequency and large acceleration.Determine the research content and significance of this article.Chapter 2,designing of the electro-hydraulic exciter system,mainly including the hydraulic schematic diagram and the hydraulic cylinder;the establishment of the system’s 5th-order mathematical modeling,through the analysis of the mathematical model,the system under the position closed-loop control of-3d B bandwidth only 12Hz;the system AMESim model is established to lay the foundation for subsequent control system research.Chapter 3,the research on three-parameter servo control.The three-parameter controller is designed and simulated based on the root locus method.A joint simulation model of AMESim and Simulink is established to verify the effect of the three-parameter controller.The designed three-parameter servo controller can effectively expand the system bandwidth to 243 Hz.Chapter 4,conducts research on the reproduction of random vibration power spectrum,and corrects and compensates the input signal in the frequency domain.H3 method is used to identify the system frequency response function,AR model method is used to estimate the PSD,and then the driving vibration spectrum is obtained using the random vibration power spectrum correction algorithm.The time-domain random driving signal is generated by frequency-domain randomization and time-domain randomization.The AEMSim model simulates and analyzes the random vibration power spectrum reproduction algorithm.Simulation results show that the system can accurately reproduce the input acceleration PSD of 5 ～ 300 Hz,and the response spectrum can converge to a tolerance range of ± 1d B except for low frequency within 10 Hz.Chapter 5,first,researching the numerical differential/integral transformation of the vibration signal of the controller.The results show that the frequency domain integration algorithm and frequency domain differential algorithm can obtain higher accuracy in the vibration signal transformation.Secondly,the software design of the controller is completed,and the dual DSP controller system is designed to improve the system control efficiency and complete the software development of the upper and lower computers.Chapter 6,summarizes the research content of this article and puts forward the future work prospects.