CN1560650A

CN1560650A - Phase-control controllable seismic focus system

Info

Publication number: CN1560650A
Application number: CNA2004100107113A
Authority: CN
Inventors: 君林; 林君; 陈祖宾; 陈鹏程; 姜弢; 张林行; 李晓旭
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2004-03-03
Filing date: 2004-03-03
Publication date: 2005-01-05
Anticipated expiration: 2024-03-03
Also published as: CN1237351C

Abstract

The invention discloses a phase controlled epicenter system, which uses a primary control unit to control at least one controllable epicenter substations. The primary control unit realizes human-computer interaction with liquid crystal screen, keyboard, realizes access through E2PROM, and realizes the principal and subordinate computers interaction through communication model. The controllable epicenter substation is made up of control model, signal generating model, power amplifying model and communication model, the communication model receives the information, controls the DDS to generate scanning waveform, which is transmitted into the power amplifier to be driven after being filtered, and the vibrator generates vibration and sends underground. When the controllable epicenter substation receives the scanning order of the primary control unit, it overlaps each quake wave in the shape phase in the fixed region underground through controlling the phase of the scanning signal, the other region is counteracted, and thus it realizes beam orientation.

Description

Phased earthquake controllable earthquake focus system

Technical field:

The present invention relates to the non-explosive source that a kind of shallow seismic exploration is used, especially vibroseis.

Background technology:

Existing non-explosion type seismic exploration seismic source has hydraulic pressure vehicular vibroseis and electromagnetic drive type vibroseis.What generally adopt at petroleum exploration domain is hydraulic pressure vehicular vibroseis, and its signal frequency range is at 6-500HZ,, maximum power output is tens KN.But because the system scan frequency band is narrow, volume is big, field work is heavy, is unsuitable for the shallow-layer high-resolution seismic survey.The vibroseis of electromagnetic drive type is a kind of portable vibroseis that designs at the shallow-layer high-resolution seismic survey.Existing product is that Japanese OYO company " vibroseis " power output of producing is limited, only is 500N.CN1643891 disclosed " controllable seismic source system for electromagnetic high-power shallow earthquake ", its swept frequency range is at 5-1400HZ, and power output is 1000N, and its sweep waveform is restricted by the waveform storage depth, be difficult to produce complicated wave form, be unfavorable for the shallow-layer high-resolution seismic survey.And, the seismic event that existing all focus produce underground be that semispace is propagated, just wherein the sub-fraction that is really received by geologic body and reflect both can't realize directed exploration, had caused the waste of energy again.This also is the common defects of existing various focus.

Summary of the invention:

The objective of the invention is at above-mentioned shortcoming and defect, the shake of having delayed time of a kind of a plurality of focus be provided, can make seismic event in underground setting regions with superimposed, sweep waveform is not restricted by the waveform storage depth, swept frequency range is wide, but multiple scanning, and can the directed phased earthquake controllable earthquake focus system of exploring.

The present invention realizes by following manner: be communicated with and control more than one and even N vibroseis substation 2 through telecommunication cable by a main control unit 1, terminal build-out resistor 3 is respectively established at the telecommunication cable two ends;

Two of single-chip microcomputer 8 I/O mouths connect parameter access 6 in the main control unit 1, and serial port is connected letter module 7;

Vibroseis substation 2 is as microcontroller with single-chip microcomputer 22, instruction according to main control unit 1, make DDS10 produce sweep waveform through storage battery conversion 15, after signal filtering 11 filtering, send into prime and amplify 16 and drive 17 through power amplifier and send into power amplification output 18 and send into vibration exciter 24 again and produce vibrations.

Good effect: by a plurality of and even N the vibroseis substation 2 of a main control unit 1 control.Determine the spacing and the platform number of vibroseis substation 2 according to scope, the degree of depth of exploration requirement.By controlling the time-delay or the initial phase of each vibroseis substation 2 sweep waveforms, make seismic event in underground setting regions with superimposed, other area parts are offset, and have realized beams directed; Swept frequency range is wide, and sweep time is long, but multiple scanning has improved capacity usage ratio, has realized the controlled and directed exploration of sweep waveform phase place, has overcome the shortcoming that sweep waveform is restricted by the waveform storage depth, has satisfied the requirement of high-resolution seismic survey.

Description of drawings:

Fig. 1 is a phased array formula earthquake controllable earthquake focus system general structure block diagram.

Fig. 2 is a phased array formula earthquake controllable earthquake focus system main control unit structured flowchart.

Fig. 3 is a phased array formula earthquake controllable earthquake focus system vibroseis substation structured flowchart.

1. control module, 2. signal generating module, 3. power amplifier module.

1 main control unit, 2 vibroseis substations, 3 terminal build-out resistors, 4 Liquid Crystal Modules; 5 Keysheet modules, 6 parameter accesses, 7 communication modules, 8 single-chip microcomputers; 9 crystal oscillator clocks, 10 DDS, 11 signal filterings, the indication of 12 states; 13 steering logics, 14 overcurrents, overvoltage, overheat protector, 15 level conversion, 16 primes are amplified; 17 power amplifiers drive, 18 power amplifications output, 19 synchronous triggering unit, the indication of 20 states; 21 communication modules, 22 single-chip microcomputers, 23 control modules, 24 vibration exciters.

Embodiment:

Main control unit is made microcontroller with single-chip microcomputer 8, and it controls the demonstration that liquid-crystal controller SED1335 is responsible for the interface on the one hand, on the other hand again by man-machine interaction is finished in the control of membrane keyboard and LCDs; The sweep parameter that is provided with can deposit parameter access 6 in, and communicates with vibroseis substation 2 by the communication port and the communication module 7 of single-chip microcomputer 8.

Main control unit 1 mainly comprises Liquid Crystal Module 4, Keysheet module 5, parameter access 6 and communication module 7, and Liquid Crystal Module 4 and Keysheet module 5 chief leading cadre's machines are mutual, and literal shows, by self-built character library realizes in single-chip microcomputer 8 memory blocks; The E of I2C bus interface has been adopted in parameter access 6 ²PROM mainly is responsible for the timely access of parameter; Communication module 7 main being responsible for to 2 parameters in each vibroseis substation or order, and feed back the state of each vibroseis substation 2 in real time, adopting the serial ports of single-chip microcomputer, its level transferring chip 15 is realized by MAX485.

Vibroseis substation 2 comprise control module 1., signal generating module 2., power amplifier module 3. with communication module 21.Control module 1. in single-chip microcomputer 22 realize the output of sweep waveforms by the DDS 10 of control signal generation module in 2., and the control prime amplify 16 and power amplifier drive 17 Kai Heguan.When the scanning beginning, single-chip microcomputer 22 control synchronous triggering unit 19 provide effective synchronous triggering agreement to the seismic event observation instrument; In scan period, single-chip microcomputer 22 state of a controls are indicated 20 parts, with the indication current working state, pass through communication module 21 simultaneously to main control unit 1 real-time feedback information.

Vibroseis substation 2 is as microcontroller with single-chip microcomputer 22, it accepts the instruction of main control unit 1, and DDS 10 is carried out process control according to the parameter that receives, produce the sweep waveform that needs, after sending into pre-amplifier 16, power amplifier driving 17 and power amplification output (18) after wave filter 11 filtering, send into vibration exciter 24 again and produce vibrations, the substrate of vibration signal by vibration exciter 24 imports into underground, produces seismic event, realizes the conversion of electric energy to mechanical energy.

Signal generating module is 2. by crystal oscillator clock 9, and DDS 10 and signal filtering 11 are formed.Single-chip microcomputer 22 produces sweep waveforms by level transferring chip 15 control DDS 10, and the linear sweep signal that is produced by DDS 10 and amplitude, frequency, the phase place of multiple nonlinear sweep signal are all able to programme, can design various complicated sweep waveforms as required.

DDS 10 also has or not transition frequency shift keying (UnrampedFSK), inclination frequency shift keying Ramped FSK except the sine wave that can produce single-frequency), 2 phase-shift keying (PSK)s (BPSK) and pulse-frequency modulation (CHIRP) pattern.But because DDS 10 is spuious bigger, signal to noise ratio (S/N ratio) is low, and the 0.5V direct current biasing is arranged, and must could remove the spuious of DDS 10 through signal filtering 11.Therefore need to be provided with Hi-pass filter and low-pass filter in signal filtering 11, Hi-pass filter removes direct current, and the low-pass filter denoising only in this way could obtain more satisfactory sweep waveform.

Power amplifier module 3. by prime amplify 16, power amplifier drive 17 and power amplification export 18 3 parts and form, 3. power amplifier module amplifies signal generating module sweep signal 2., to reach the enough driving forces to vibration exciter 24.Be holding circuit, also be provided with overcurrent, overvoltage, overheat protector 14.When electric power generation overcurrent, overvoltage, excess temperature, steering logic 13 is cut off the power supply of prime amplification 16, power amplifier driving 17 and power amplification output 18, and notify status indication 12.

By the information interaction of communication module 21 realization principal and subordinate machines, comprising: main control unit 1 is to the parameter transmission of vibroseis substation 2, the start and stop of scanning etc.; The signal feedback that main control unit 1 is given in vibroseis substation 2, the operation conditions of monitoring vibroseis substation 2.Because adopt master-salve distributed structure, main control unit 1 is prior arts to the communication of vibroseis substation 2,, can solve by the timesharing transmission because there is bus collision in the communication of the 2 pairs of main control units 1 in vibroseis substation.

Phased earthquake controllable earthquake focus system adopts half-duplex mode, forms a distributed system by 1 above vibroseis substation 2 of a main control unit 1 control, can also 1 to N vibroseis substation 2 be set according to need of work.For normally carrying out of communicating by letter, a terminal build-out resistor 3 need be respectively established at the telecommunication cable two ends.During work, main control unit 1 comprises initial, the termination frequency of scanning, scanning form, sweep time, triggering mode etc. earlier to 2 sweep parameters in each vibroseis substation; Send out the beginning scan command then, each vibroseis substation 2 starts scanning after receiving order, and they bases station number separately by the phase place of control delay time or sweep signal, starts scanning; Sweep signal is sent into pre-amplifier 16 after wave filter 11 filtering, through power amplifier drive 17 and power amplification output 18 deliver to vibration exciter 24 and realized simultaneously seismic event to underground transmission out of phase, to compensate between each focus because the phase differential that wave path-difference causes, make seismic event in underground a certain zone with superimposed, realized beams directed.

Claims

1, a kind of phased earthquake controllable earthquake focus system that is mainly used in seismic prospecting comprises main control unit (1) and vibration exciter (24), it is characterized in that:

Be communicated with and control more than one and even N vibroseis substation (2) through telecommunication cable by a main control unit (1), terminal build-out resistor (3) is respectively established at the telecommunication cable two ends;

Two I/O mouths of single-chip microcomputer (8) connect parameter access (6) in the main control unit (1), and serial port is connected letter module (7);

Vibroseis substation (2) is as microcontroller with single-chip microcomputer (22), instruction according to main control unit (1), make DDS (10) produce sweep waveform through storage battery conversion (15), after signal filtering (11) filtering, send into prime and amplify (16) and drive (17) through power amplifier and send into power amplification output (18) and send into vibration exciter (24) again and produce vibrations.