Experimental Research On Active Vibration Isolation System Of Controllable Seismic Source

A vibrator is a kind of geophysical equipment applied in oil and gas exploration,it can produce a frequency changed continuously signal in seismic exploration to detect oil and gas reservoirs.And vibration isolation system is closely related to the vibration source is of great significance for signal performance improving.Up to now,the vibration isolation method adopted in the present era can achieve more than 90%isolation efficiency at the excitation frequency of 6-250Hz,which can meet the excitation requirement of seismic exploration.The vibration isolation efficiency is far from meeting the requirements if the excitation frequency less than 3Hz signal.In this paper,an experimental model is established to match a vibrator,the active vibration isolation technology is added,and the experiment of active vibration isolation system is studied.This paper analyzes the structure and working principle of vibration isolator system,establishes the physical model and mathematical model,and simulated by ZK-5VIC virtual test vibration and control system.Aiming at the complex low frequency vibration signal,the experiment platform of the hybrid vibration isolation system is set up.The single-chip microcomputer is used as the main controller and the electric vibrator as the active vibration isolation system.The vibration isolation control model of the vibratory seismic source is established through study of the control algorithm and a PID control algorithm is finally determined.The experimental results show that the vibration isolation effect of the hybrid vibration isolation system is 80%at 3Hz,83%at 2Hz and 86%at 1Hz,which provides a theoretical basis and technical support for the vibration control of low frequency vibration control.The main summaries of this paper are as follows:1)Aiming at the low frequency vibration signal,a hybrid vibration isolation scheme is designed.The hardware is implemented with 51 MCU as the main controller,and the software adopts the PID control algorithm to realize the experimental study of the active vibration isolation with vibration frequency below 3Hz.The results show that the vibrating vibration frequency of the vibrator can reach more than 80%at 3Hz?1Hz,and the vibration isolation effect is acceptable.2)The vibrating frequency of the vibrator is in the range of 3Hz?1Hz,the amplitude of the vibration curve at different time points is obtained,and the relevant data are processed mathematically.The result is proven that the higher the frequency,the more stable effect for the active vibration isolation.3)The vibration isolation curve is transformed from time-domain to frequency-domain,and then the active vibration isolation efficiency is obtained again through the vibration isolation curve shown in the frequency domain.It is verified that the vibration isolation effect can reach more than 80%for the frequency range from 3Hz to 1Hz.