Generalized predictive control system of vibroseis

Abstract

The invention relates to a generalized predictive control system of vibroseis. The system takes a DSP as a main control chip to control a keyboard module and a liquid crystal display module, and realizes rapid communication through serial communication, SPI communication and an FPGA. A vibroseis model parameter identification module is programmed and constructed in an FPGA, and large scale computation in a control quantity resolving module is realized in a DSP through SPI communication. The system adopts the FPGA, is small in circuit volume, high in integration level, high in noise reduction effect and high in computing speed. The system solves the problem that as vibroseis excited signals are restricted by factors, such as source control signals and vibroseis structures, vibroseis has nonlinearity, and a base plate and a ground-coupled system are changed with ground-surface conditions and underground structures of a construction region, so that good control accuracy is difficult to obtain. The system is particularly applicable to vibroseis control in complex construction conditions, can reduce output signal distortion of a source system caused by factors, such as long-term use and ageing, of the source system, and improves the vibroseis control accuracy and system robustness.

Description

Technical field: [0001] The invention relates to a control system of a vibrator, in particular to a generalized predictive control system of a vibrator. Background technique: [0002] The vibroseis can excite small-energy controllable vibration signals to the ground, and use the method of pulse compression to achieve the excitation effect of high-power seismic waves similar to explosive vibrator. Due to the advantages of controllable waveform parameters, safety and environmental protection, vibroseis has been widely used in seismic exploration. However, due to the poor coupling between the vibrator substrate and the ground and the nonlinearity of the system, the open-loop output signal of the vibrator has serious signal distortion. The excitation signal is out of phase with the input signal. The distortion of the vibroseis excitation signal will have a serious impact on the accuracy and resolution of seismic exploration. There have been many studies abroad on feedback con...

AI Technical Summary

Problems solved by technology

However, due to the poor coupling between the vibrator substrate and the ground and the nonlinearity of the system, the open-loop output signal of the vibrator has serious signal distortion. The excitation signal is inconsistent with the input signal phase

The distortion of the vibroseis excitation signal will have a serious impact on the accuracy and resolution of seismic exploration

There have been many studies abroad on feedback control of vibrator. Laing used a phase-locked loop to track the phase of the acceleration of the vibrator substrate. However, the phase-locked loop uses zero-crossing detection to obtain phase information, which is vulnerable to high-order harmonics and environmental noise. influence, causing phase misjudgment

Sercel uses Gaussian quadratic optimal control to achieve feedback control of its seismic source, but still relies on the seismic source and the coupling model of the seismic source and the ground to a certain extent

However, the surface and underground environments involved in the vibrator seismic exploration process are complex and changeable, and the model is greatly affected by the environment.

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