Signal Design And System Development Of Portable Hydraulic Impact Seismic Sources

In association with the national major project of863plan of "Key techniquesand equipments of metallic mineral deposit", the paper launched a study on thesystem development of portable hydraulic impact seismic sources, according to thecharacteristics of the seismic sources system, and designed for a hydraulic system inscanning signals. In portable hydraulic impact of seismic sources system, thehardware designed, and control scheme formulated, and the design of the scanningsignals are based on solid theories and experiments for the foundation. On portablehydraulic impact of seismic sources system of research, the paper provides acorresponding reference for hydraulic drive of seismic sources in the furtherdevelopment of the use.Overall, this paper expounds the important significance of controlled seismicsource in seismic exploration, and the application of related technology and thescanning technology in the field of seismic exploration, and the record principle ofpulse coding sequence scanning signal. This paper discusses the hardware andsoftware design of portable hydraulic impact seismic sources system, on thecharacteristics of portable hydraulic impact of seismic sources, designs a singlelinear impulsive scanning signals and multiple piecewise linear frequency signals.Through the experiments, it is verified that the design scheme of portable hydraulicimpact seismic sources system is the feasibility and high efficiency.The major contents of this paper are as follows.According to vehicle-mounted hydraulic drive of vibroseis' huge volume, insome areas of the complex terrain, its efficiency of the work is lower, and even can'tbe used. The paper designed the portable hydraulic impact seismic sources system.Through the analysis of continuous sweep frequency technology and Mini-Sosie technology, and according to the characteristics of hydraulic transmission, the paperdesigned linear pulse scanning signals for the hydraulic impact system. Around theseismic exploration theory, and the design of the scanning signals, and the design ofsoftware and hardware in seismic sources system, and experimental research, thepaper made a systematic study of the portable hydraulic impact seismic sourcessystem.This paper summarized the principle of seismic exploration of controllableseismic source, related technology and scanning technology in the seismicexploration areas, and analyzed and summarized the autocorrelation function of theconsecutive series of linear and nonlinear sweep frequency signal. In view of highquality sweep frequency signal is difficult to realize in the actual seismic exploration,and made a detailed study of pulse coding sequence scanning technology, the paperdesigned scanning signals for hydraulic transmission system, and deduced theexpression of the scanning signals stimulate rules, and provided the theory basis fora software program designed for the control system.The hardware and software design, the modular design system is used in theportable hydraulic impact seismic sources system. According to the functions of theparts of the system is different, the whole system into three subsystems-the powersystem, control system, and execution system. Modular technology not only reducesthe total weight of the system, and can be quickly set up of seismic sources platform,and greatly improves the portability of the source system. The paper made discuss indetails, including the system's general structure, subsystem structure and function,and provided the subsystem structure diagram. In the control system, theintroduction of small PLC as the control systematic core, improves the stability ofthe system, and control accuracy and the anti-interference ability. In the executionsystem, according to the characteristics which the mechanical structure of the sourcevibration exciter, execution system designed the substrate; substrate quality weightand low gravity, further improve the coupling between the source system and theearth.In the study of the portable hydraulic impact seismic sources system, through did a lot of system testing experiments, find the best work parameters of the wholesystem. After grasped the system of the parameters of the best of the work state, inthe same conditions, used different control schemes for experiments. In order to beable to better reflect various performance indicators, in the experiment, made acomparison between the portable hydraulic impact seismic sources system andCanada VIBSIST50seismic source.The main achievements that the paper acquired were:1. The design of the scanning signals of the seismic sources system, used forreference of sweep frequency technology and Mini-Sosie technology, after did thecombination and improvement, putted forward a single linear impulsive scanningsignals and multiple piecewise linear frequency signals, deduced the mathematicalexpressions of the variation of the scanning signals. Compared to two signals, theseismic wave signal inspired by multiple piecewise linear frequency signals, closerto random signal pulse sequences, be able to improve the SNR of the seismic wavesignal.2. In hardware design of the seismic source, the modular design of the wholesystem structure improved systematic portability. In the control system, the use ofPLC enhanced the control precision of the system and the anti-interference ability.Programming software of PLC is simple and practical, and easies to softwaredevelopment and maintenance. The monitor of PLC, realized real-time monitoringof the output signal from the control system. Substrate use of the execution system,improved the coupling between the source system and the earth.3.3. Through have done a lot of system testing experiments, found theparameters of best work and the critical state, for example, scanning signals schemeof multiple piecewise linear frequency signals, when the source vibration exciterstart to work, the output signal from logic controller of ZelioLogic not less than3.55mv. The experiment under the same environment, analyzed the seismic data afterdecoded, compared with a Canadian source of VIBSIST50, the seismic wave signal,stimulated by the portable hydraulic impact seismic sources system, has strongeroutput force, and transmission distance is farther, and higher resolution.