CN101825723A

CN101825723A - Offshore earthquake measurement method and system

Info

Publication number: CN101825723A
Application number: CN200910166395A
Authority: CN
Inventors: 肯·维尔克尔; 比德·泰勒
Original assignee: Westerngeco Seismic Holdings Ltd
Current assignee: Westerngeco Seismic Holdings Ltd
Priority date: 2004-03-17
Filing date: 2004-03-17
Publication date: 2010-09-08
Anticipated expiration: 2024-03-17
Also published as: CN101825723B

Abstract

The invention relates to a method for controlling an earthquake measurement spread during earthquake measurement. The spread is provided with a ship, a plurality of spread control elements, a plurality of navigation nodes, a plurality of earthquake focuses and receivers. The method comprises the step of input data collection, wherein input data comprise navigation data of the navigation nodes, operation state data generated along with a sensor of the spread control elements, measurement environment data and measurement design data. The positions of the earthquake focuses and the receivers are evaluated by using the navigation data, the operation state data and the measurement environment data. The best path lines of the earthquake focuses and the receivers are determined by utilizing the position evaluation and at least one part of input data including the measurement data. A driving instruction for at least two spread control elements is calculated by using the determined best path line. The method is realized by the system provided by the invention.

Description

Marine seismic survey method and system

It is 200480042924.2 (international application no is PCT/US2004/008029) that the application of this division is based on application number, and the applying date is on March 17th, 2004, and denomination of invention is divided an application for the Chinese patent application of " marine seismic survey method and system ".

Technical field

What relate generally to marine seismic data acquisition of the present invention was measured finishes, and in particular, relates to during measuring the control to the seismic surveying spread.

Background technology

Finish the marine seismic data acquisition measurement and be usually directed to one or many surveying vessels, they respectively pull at least one earthquake towed cable and pass water body, and this water body is considered to cover on one or more stratum of containing hydrocarbon.Obtain measurement in order to finish the 3D marine seismic data, drag back at ship, each towing cable of this array to have several kms long and comprise wave detector in the big water gaging and the electronic equipment followed distributes along the length direction of towing cable usually an offshore seismic towing cable array by seismic survey vessels with about 5 nautical miles/hour speed.This ship also pulls one or more earthquake sources that are suitable for using, normally air cannon in water.The voice signal that is produced by earthquake source, or claim " blast " passes water body and propagates into undergroundly, and voice signal is reflected by various stratum there.The signal of reflection is received by ondometer in the water that carries on the towing cable, and digitizing is sent to seismic survey vessels then, and digitized there signal goes on record and be processed at least partially, and its final purpose is the expression that makes up stratum in the measured area.

Often obtain the two or more groups seismic signals from same subterranean zone.For example, can be on the same area carry out twice or more times seismic surveying obtains these group seismic signals in the different time, the time interval between each secondary earthquake is measured usually is that some months did not wait to several years.In some cases, the acquiring seismic data signal is used for monitoring because the variation of the underground reservoir that production caused of hydrocarbon.Also occurred in recent years specifically carrying out the collection and the processing of the 3D seismic data signal at interval if having time above the lower area, as new important method of seismic prospecting (so-called " 4-D " in the field of business geological data).

Common practice is some information of collecting in advance about measured zone, thereby can select suitable equipment and method (being called " measuring design ") to realize desirable geophysical and the target of operating.Some such information are used to provide measures required basic parameter, as the border of measured zone, and the igniting situation of the length of towed towing cable cable and earthquake source etc.These information are used to run through the measurement control of each autonomous system to a certain extent.The representative instance of this class control system is self-navigation, ship's head control and the towing cable location and the depth adjustment of surveying vessel.For example, United States Patent (USP) 6,629, describe use cost map (cost map) for No. 037 and optimized the path of in known measurement zone, encrypting the seismic section operation, disclose the position of in a known measured zone, determining focus and towing cable according to the position data that writes down by previous measurement UK Patent Application GB2364388 number.

Everybody also knows during measuring (promptly in real time or in real time near) collects about measuring some information of implementation status, thereby can be according to the suitable setting and the location of realization of goal of desirable geophysical and operation.These information also are used to run through the measurement control of each autonomous system to a certain extent.Following references has been represented the state-of-the-art technology of this class control system: United States Patent (USP) 6,618, No. 321 (coming towing cable position during the analogue measurement according to the current of measuring); United States Patent (USP) 6,590, No. 831 (coordinating many earthquake data acquisition ships during the one-shot measurement) according to the measurement parameter of being monitored; United States Patent (USP) 6,418, No. 378 (neural network of train by the data of measure gathering is used to predict the shape of earthquake towed cable during next measurement); United States Patent (USP) 5,790, No. 472 (earthquake towed cable during measuring being located) according to detector noise level in the water; And International Patent Application WO No. 00/20859 (estimating speed according to the paravanes device is located the earthquake towed cable during measuring) and No. 6,691,038, United States Patent (USP) (being used for being pulled active the separation trace and the positioning system of seismic array).

Above-described control system depends on specific input (as marine current) to determine to can be used for controlling the information of seismic surveying towboat.Yet neither one depends on or considers the initial conditions and the parameter of wide region in these systems, and they comprise the restrictive condition of various purposes and seismic surveying equipment and method.Have, one group of collaborative guide piece that neither one attempts to utilize in whole spread district (comprise focus and receiver the two) to dispose in these systems is controlled this spread on one's own initiative, so need such complication system again.

Designed above-mentioned control system, realized desirable result by providing immediately the order that realizes or path to wait.Consider seldom aspect being optimized or do not consider at all in important time delay effect these outputs.So need a kind of like this seismic surveying control system, it also considers the delay effect of output (particularly control command) when considering immediately effect.

Definition

In this description, some terms are defined when they use for the first time, and some other term definition in this description are as follows:

" angle of attack " is fin or the deflector angle with respect to fluid (being water) flow direction.The angle of attack is a derived quantity, is that orientation, the fin in system reference system comes out with respect to the controlled or fixed orientation and the current orientation calculation in system reference system of deflector/body by deflector that is used for fixing fin or body.When fin/deflector did not have lifting, it had zero angle of attack.

" zone rotation " is meant the axis rotation that measures from the axis that is orientated northwards, and like this, for example 0 ° of zone rotation is meant that the seismic section operator is north to (or tow direction).This provides the relatively orientation of axis of zone, and the seismic section operator who determines this measurement to.

The spread coordinate that the measurement that " reference measurement " delayed when being meant is attempted the original measurement of reference and followed.

" good route " is meant the actual course line with respect to the seabed.

" laterally " and " vertically " be meant respectively perpendicular to the direction that is parallel to tow direction, definition in regional relative reference system.The initial point of reference frame can be transformed into the position of surveying vessel.An example of longitudinal axis orientation is to be parallel to seismic section operator by previous measurement appointment to (for example line direction of design or zone rotation in advance).

" drive and order " change that is meant spread control assembly mode of operation, this will provide the hope result of spread position.

" power model " is meant a kind of expression of one group of effective fluid power educational level to the influence of spread, and this expression is by computer implemented.This power model comprises the expression to spread and its place medium (being sea and atmosphere).This medium comprises from being less than 40m depths vertical area tens meters on air/boundary at the sea face under the sea.That outside this defined range, produce but also be the candidate target that is used for modeling to this regional influential power.

" natural plum grape " is meant by the angle between the straight line of any 2 definition on the towed body and the reference direction, and this reference direction is the ship direction of carrying out the seismic section operation normally, because current, wind or both effects obtain above-mentioned position at 2.Example is the angle that connects between the formed straight line of towing cable head and the tail and the line direction that designs in advance.

" in real time near " is meant the data stream after the time-delay in some way, as allows the result of calculation of using balanced-filter to obtain.Usually, the decision that utilizes this class data stream to make is used to strengthen the decision of making in real time.Real-time and near real-time data flows the two to be used by the next process in the decision flow process after being received immediately.

" position history " is meant the coordinate of any spread element that constitutes spread parts (as towing cable or focus array) or element set or shape in each discrete estimated value constantly, is given in a average velocity on this mistiming in discrete two coordinates that constantly obtain or shape estimated value.Provide two average velocitys and an average acceleration three different three coordinates or shape estimated values constantly.

" PID " or " PID controller " is meant ratio---integration---derivative controller.It is a kind of feedback controller, and its output is a control variable (CV), normally based on the two poor of certain set-point defined by the user (SP) and process variable (PV) that certain measures.

" prediction residual " be meant spread modal position coordinate predicted value with independent measure based on the two poor of the position coordinates of navigation.This term is borrowed from the Kalman Filter Estimation theory.

" current measurement " is meant raw data set, result of calculation or the action that has produced in the current measurement route that carries out.These can be with in real time, used closely in real time or as required.

" historical before measuring " is meant any data used that produce before this measurement beginning when preparing or carry out this measurement.Example comprises the historical record of reference measurement, sea chart, morning and evening tides information, depth information, seismic surveying figure, wellhole data, bin (binning) data and natural plum grape.This category information may be may not be in PD also.These data may obtain during pacing just.

" in real time " is meant except producing data stream and forms the data stream that part produces under the situation without any additional delay the required shortest time again.This means between the extraction of information stores in data stream and this information and do not have big gap.A further requirement is preferably arranged, and promptly these data stream composition parts produce enough soon, and the control decision that allows to use them to make enough comes into force early.

" demolition point " is meant the pairing chronomere of the time interval between each earthquake data acquisition incident.

" demolition point coordinates of targets " is meant to collecting the expection two-dimensional coordinate that the whole spread objects of geological data are occupied.This group coordinate can also be used to derive the shape of spread body target.

" spread " is meant the sum of " spread parts ", i.e. the sum of ship, means of transport and towed object (comprising cable), and they use together, measure to carry out marine seismic data acquisition.

" spread shape " is to describe any mathematical function that is pulled the spread component shape.For example, can think that the towing cable cable has the rectilinear form that passes through.Another kind of expression way is, this shape can be a series of straight lines or higher order polynomial more, and their couple together any one group of position coordinates estimated value along towing cable, thereby provide the approximate shapes of whole towing cable.Similarly method can be used for the earthquake source array.

" spread control element " is meant controllable spread parts, and it can make spread parts along laterally or vertically changing coordinate.

" spread control element mode of operation " is meant those measurements that provide the information relevant with spread model (as hydrodynamic force educational level model).Example comprises flow rate on fin body orientation, the deflector, the wing angle with respect to the fin body, rudder angle, propeller speed, the pitch of screw propeller, the tension force of trailing cable etc.

" spread control element performance index " or " performance index " are meant individual element or by the performance boundary of the system that constitutes of whole spread control elements.Example comprises the scope of the possible wing angle value of fin control element, the tension limit of trailing cable, the angular stop of deflector means etc.

" spread front end " be meant connect each towing cable front end, what are perpendicular to a line of the good route of ship (best-fit or actual).

" spread model " or " model of spread " is meant the code that can be read and be carried out by computing machine, is used for by the response of this spread of computer simulation to various input power and condition.The spread model can be hydrodynamic force educational level model, nerve network system, closed-loop control system (for example seeing International Patent Application WO No. 00/20895), be driven and the motion model or the Kalman filter of calibration by L-norm best-fit criterion.

(claiming SFED again) is meant the turned to deflector of the front end that is positioned at outermost towing cable " can to turn to the front end deflector ", as the MONOWING device of Western Geco company.

" turn to plum grape " and be similar to the nature plum grape, but this angle is changed by steering gear.

" steering gear " is to instigate at least one spread parts to turn to the device of usefulness.But this class device comprises the towing cable steering gear, can turn to front end deflector and turning buoy.

" towing cable steering gear " (claiming SSD again), be meant the steering gear that distributes along towing cable, as the Q-FIN of Western Geco company ^TMDevice.

" towpoint " is the initial point (for example, on afterdeck import some position that cable withdraw from coaster place) of towed spread object on towboat.

" trace " is meant the preassigned two-dimensional coordinate that the spread parts will occupy when carrying out a part of earthquake and measure, as seismic line.Example comprises the survey line of design in advance or measures preceding one group of non-directional coordinate setting.

" track " be meant any spread parts occupy during measuring realization or one group of actual coordinate.

" translation " is meant the transfer of initial point X and Y coordinates, and it provides the required new initial point of navigation.

" translation function " is meant the series of computation that takes place in computing machine, it provides amount various measurements or projection as input, and providing one group of driving order as output, these orders are designed to provide variation design or that wish of any amount object's position.

Summary of the invention

On the one hand, the invention provides a kind of method, be used for control seismic surveying spread when carrying out seismic surveying, this spread has a ship, a plurality of spread control element, a plurality of navigation node and a plurality of focus and receiver.This method comprises the step of collecting the input data, and these data comprise the aeronautical data that is used for each navigation node, the mode of operation of following the sensor of spread control element to provide, required environmental data of seismic surveying and seismic surveying design data.Use aeronautical data, mode of operation and environmental data to estimate the position of focus and receiver.Use these location estimation values and part input data to determine (comprising the seismic surveying design data at least) the best trace of focus and receiver.At least be to use determined best trace, calculate the driving order that is used for two spread control elements at least.

Estimation in the inventive method, determine and calculation procedure can be carried out by translation function.More particularly, can be according to the spread model estimated position in the translation function.In one embodiment, the spread model uses first group of estimated position of input data computation, and these input data comprise mode of operation and environmental data at least.Collected aeronautical data comprises second group of position of estimating.First group and second group of estimated position are combined in together in translation function, produce the focus estimated and the residual error of receiver position and prediction.The residual error of prediction is used to estimate one group of parameter that characterizes the spread model.The spread model parameter is used to calibrate the spread model.The residual error of prediction can be further used for estimating to collect the used sensor errors state of environmental data.

Can determine best trace according to the weighting function in the translation function.In one embodiment, weighting function receives the estimated position of seismic surveying design data and focus and receiver as input.Can comprise the performance index of spread control element from the input of seismic surveying design data, as turn to restriction.In this embodiment, weighting function is used for the input data are used relative weighting coefficient, is used for the best trace by the translation function compute spread.

In a specific embodiment of the inventive method, the spread model is the hydrodynamic force educational level model of spread parts.This power model can be based on water flow data and other data.In other embodiments, the spread model is the pure statistical model of spread parts, is neural network, or utilizes one of L norm match criterion.All these embodiment have the ability to carry out parametrization based on the spread control that whole inputs are learnt subordinate act history, and can produce and drive order, these orders will realize one group of optimized extraterrestrial target, or they are with the form (for example demolition point target) of coordinate or with the form (as turning to plum grape) of shape, are used for following spread.

In a specific embodiment, the estimation spread response time also pays attention to when calculating the driving order.In this embodiment, drive order and also be restricted to keep the stable of spread and before sending to the spread control element, to confirm its validity.Driving order---particularly those are used to control the order of ship---can realize by hand or automatically.Because it is slow that great majority drive the response time of order, so are operating personnel some occasion implementors.Other drive order, change as SSD wing angle, and then preferred control automatically is as described in International Patent Application WO 00/20895.

Can drive the validity of order according to the confirmation request of geophysical and operation.Geophysics requires to comprise the covering of realization to the hope of a subterranean zone, the seismic signal raypath of one-shot measurement before repeating, and control seismic sensor noise.Operation requires to be included as spread and passes the hazardous location and determine one or more escape way, determines to carry out the Best Times of one or more seismic surveying line, and reduces time incidental.Correspondingly can calculate other and drive order to realize the escape way between two or more definable positions.

In case obtain confirming, drive order and just be sent to the spread control element to reach desirable measurement target.Drive order and can comprise that control is the driving order of one of ship screw propeller, ship thruster, spread parts steering gear and ship reel truck at least.

Preferably, each to drive that order is used to control be one or more position component, speed and the working direction thrin of spread at least.The spread parts generally include one or many ocean goers and by a plurality of parts of at least one ship towing.Towed parts generally include cable, sensor (as wave detector in the water) and steering gear (as turning to front end deflector (SFED) and towing cable steering gear (SSD)).The spread parts can further comprise not and this or many or many cargo ships that surveying vessel is tied, as cargo ship (AUN) or water surface cargo ship (ASV) under water automatically automatically.

The spread control element comprises rudder, screw propeller, thruster, one or morely is used for making by the device that drags cable and instrument to turn to and one or more at least two of turning to device such as flotation gear.Follow the sensor that is used for being created in the mode of operation collected of input data of spread control element to comprise one or more sensors in the sensors such as tension force, flow rate, inclination, orientation, acceleration, speed and position.

The environmental data of collecting in the input data comprises one or more data types in the data such as current, salinity, temperature, pressure, the velocity of sound, unrestrained height, unrestrained frequency, wind speed and wind direction.

The seismic surveying design data of collecting in the input data comprises zone, the degree of depth, zone rotation or seismic section operation orientation, survey line coordinate, focus and receiver position, one or more data types in the data such as required coverage, partial restriction, the optimization factor and historical data.The seismic surveying design data further comprises the performance index of spread control element, as ship, can turn to cable unit, can turn to the towing and the maneuvering characteristics of seismic source apparatus and deflector etc., the towing characteristic of towed cable, focus and flotation gear, and the operating characteristic of winch.The seismic surveying design data can also be characterized by spread trace performance index and measurement target.

The input data set of collecting can also be characterized by and comprise measurements in advance, operator's input, current measurement, closely in real time or real-time one or more data types such as measurement and analogue measurement.

Measurement data can comprise environmental sensor data and historical measurement data in advance.

The operator imports data can comprise setting of spread parameter and environmental data.

Real-time measuring data can comprise cable stretch, flow rate, inclination, orientation, acceleration, speed, position, the setting of spread control element, environmental data, seismic signal and one or more data types such as noise data and operator's input.Collected position data can comprise the data from one or more sensors in one group of sensor such as gps receiver, echo sounder, depth transducer, acoustic ranging system, magnetic compass, gyrocompass, radio positioning system, accelerometer and inertia system.The spread control element is provided with data can comprise one or more input data in one group of data such as thruster setting, airscrew pitch, revolution speed of propeller, rudder angle, trailing cable tension force, winch position, deflector orientation, the deflector angle of attack, deflector water speed, towing cable steering gear orientation and the towing cable steering gear fin angle of attack.

The analogue measurement data can comprise operator's input of the preceding data of the measurement of simulation, simulation, current measurement, the near real-time data of simulation, the real-time measurement of simulation and one or more data types such as environmental data of simulation of simulation.

The original seismic sensor data of collecting during seismic surveying also can be characterized as being the input data.So in one embodiment, method of the present invention further comprises uses original seismic sensor data to produce the step of estimated position quality indication.These quality indications can comprise bin data set, absolute noise data, signal noise ratio and seismic signal frequency content.The quality indication can be used for confirming real-time measuring data, spread control operation state and the validity that drives order.

On the other hand, the invention provides a system, be used for control seismic surveying spread when carrying out seismic surveying, this spread has a ship, a plurality of spread control element, a plurality of navigation node and a plurality of focus and receiver.This system comprises that a database is used for receiving the input data, comprises the aeronautical data that is used for each navigation node, the mode of operation of following the sensor of spread control element to provide, required environmental data of seismic surveying and seismic surveying design data.This system further comprises: have the computer-readable medium of computer executable instructions, these instructions use aeronautical data, mode of operation and environmental data to estimate the position of focus and receiver; Computer-readable medium with computer executable instructions, these instructions use estimated position and part input data to determine (comprise at least and measure design data) the best trace of focus and receiver; And the computer-readable medium with computer executable instructions, these instructions use determined best trace to calculate the driving order that is used at least two spread control elements at least.

In an embodiment of system of the present invention, the instruction that the estimated position is used is determined the instruction that best trace is used and calculates the instruction that drives order usefulness to be included in the common computer-readable medium.

In a specific embodiment, system of the present invention further comprises: the computer-readable medium with computer executable instructions, these instructions are used to confirm the validity of the driving order that calculates; And a network, be used for the driving order that efficiency confirmed is sent to the spread control element, thereby can obtain desirable measurement target.

In other words, system of the present invention expection realizes and comprises the characteristic of the inventive method of above-outlined.

Description of drawings

For characteristics of the present invention and the advantage of can understood in detail above quoting from,, can obtain more specifically description to the invention of above-outlined by the embodiment of the invention shown in reference to the accompanying drawings.Yet, be noted that accompanying drawing has just shown exemplary embodiments of the present invention, thus should not be construed as the restriction of scope that the present invention is sent out, because the present invention can permit having other same effectively embodiment.

Figure 1A is the planimetric map that is used to carry out the seismic surveying spread that offshore seismic measures.

Figure 1B is the elevation drawing of spread shown in Figure 1A.

Fig. 2 is the process flow diagram that is used to control the method for this spread according to an aspect of the present invention.

Fig. 3 is the schematically showing of towed streamer that shows constant plum grape.

Fig. 4 is the schematically showing of a plurality of towing cables that shows constant separate mode.

Fig. 5 is schematically showing of best towing cable shape, and this model is to utilize along the local plum grape of each section of towing cable definition to determine, to realize measuring with previous towing cable the best-fit of shape.

Fig. 6 is schematically illustrating of the best-fitting straight line that obtains according to four demolition point eyes fronts predictions, and residual prediction value wherein is based on that position calculation after at every turn detonating comes out.

Fig. 7 is the schematically showing of eyes front best-fitting straight line (as shown in Figure 6) combination in succession.

Fig. 8 A-8B schematically illustrates and how to utilize the focus plum grape to represent the focus lateral drift that is caused by current, and current and ship's speed vector resolution.

Fig. 9 schematically shows the correction or the change of towing cable front end, and it causes towing cable front end and the angled skew of good route, to overcome the crab angle θ that is caused by current.

Figure 10 schematically shows the towing cable front end center that turns to trace that is fitted to a hope.

Figure 11 and 12 schematically shows " best-fit " line of reference measurement towing cable how to estimate to have common slope and converts thereof into the common plum grape of all towing cables of each blast.

Figure 13 schematically illustrates the best slope that principle shown in Figure 11-12 is applied to estimate single towing cable.

Embodiment

Figure 1A-1B illustrates and carries out the typical marine seismic data acquisition measurement spread (also being called for short " spread ") 10 that the 3D seismic surveying is used.Spread 10 characterizes with a plurality of parts, and the some of them parts are controllable, is called the spread control assembly.The spread parts generally include one or many seagoing vessels 11, as at United States Patent (USP) 6,216, and the seagoing vessel of describing in 627, and at least by a plurality of parts of a ship towing.Towed parts comprise cable, as lead-in cable 20, and tabula line 26, towing cable 18, wave detector 21 in focus towing cable and pressure line (the two is expressed as 15) and focus 16 and the water on towing cable also has steering gear, as deflector 22, towing cable steering gear 38 and focus steering gear 17.

The spread parts can further comprise not and one or many or many cargo ship (not shown) that surveying vessel is tied, as at United States Patent (USP) 6,028, the unmanned dynamic ship of describing in 817, United States Patent (USP) 6, the cargo ship of describing in 474,254 under water automatically, or the seabed tractor of description among International Patent Application PCT/GB01/01930 (WO 01/84184).

The spread control element generally includes rudder R, screw propeller P, is dragged into the device (not shown), one or morely be used for making the

device

17,22,38 that dragged cable and instrument to turn to and one or more at least two of turning to device such as flotation gear 46,52.

More particularly, at Q by assignee of the present invention all and operation ^TMIn the situation of surveying vessel, surveying vessel 11 has gps receiver 12 and an integrated computer based earthquake omniselector (TRINAV ^TM) coupling, also have energy source controller (TRISOR ^TM) and record (TRIACQ ^TM) 14 (the general name TRILOGY of system ^TM), this ship pulls a plurality of earthquake sources 16, is generally TRISOR ^TMThe sort of multiple air gun of in our United States Patent (USP) 4,757,482, describing of control, and the array 19 that constitutes by four essentially identical towing cables 18.Yet, will be understood that, in fact can pull nearly 20 towing cables, for example use the technology of describing among the International Patent Application PCT/IB98/01435 (WO 99/15913) that authorizes the assignee of the present invention.Towing cable 18 is pulled (be that plow-steel or optical fiber are strengthened cable, they transmit power supply, control and data signal between ship 11 and towing cable 18) by their importing cables 20 separately.The stretching, extension of outermost towing cable 18 can turn to front end deflector (SFED) control by two, is called MONOWING ^TMDeflector, 22 places point out at label, are connected to two or more outermost towing cables front end 24 separately.The United States Patent (USP) 5 of authorizing the assignee of the present invention, 357, the SFED 22 that describes in detail in 892 concurs with each shielding wire 26 that is connected between the front end 24 of the front end 24 of each outermost towing cable and adjacent towing cable thereof, between each towing cable 18 of assistance maintenance essentially identical interval to be arranged.

Wave detector 21 distributes at certain intervals along the length of towing cable in every towing cable 18 comprises a plurality of (the most nearly 4000) water.Detecting device 21 independent lines in each water, make its output energy by digitizing and filtering separately, thereby allow to carry out complicated processing, be called " combination of numbers formation ", as authorizing as described in International Patent Application PCT/GB99/01544/ of assignee of the present invention (WO99/60421).

Every towing cable 18 is made of a large amount of essentially identical streamer sections, and these streamer sections are end-to-end to link together.Each streamer section has an outer plastic skin, it comprises several long stress assemblies, the stress assembly of making by Kevlar for example, and wave detector 21 in the water, wave detector is separated by the polyfoam isolated material that is full of kerosene in these water, as authorize assignee of the present invention's United States Patent (USP) 6,477, as described in 111.The another kind of practice is that each streamer section can utilize " solid " structure, as the commercial prod of Sercel and Thales submarine system company.

Every towing cable 18 also has towing cable steering gear (SSD) 38 in a plurality of lines, is also referred to as " steering gear ", the sort of Q-FIN that describes in preferred U.S. Patent application US20020126575 number ^TMSteering gear, they distribute with the degree of depth of control towing cable and it are laterally turned to so that 200m is at interval along the line.In addition, acoustic transmitters or " signal generator " 40 were along the line in every towing cable 18 was wired evenly distributes, and signal generator is placed between steering gear 38.Signal generator 40 is hereinafter with the part of the position fixing and navigation system that further describes.

The tail end 42 of towing cable 18 promptly away from that end of surveying vessel 11, is connected in separately tail buoy 46, tail buoy via separately elongated portion 44 (being similar to elongated portion 36) and is furnished with separately signal generator 48 (being similar to signal generator 40).And gps receiver separately 50.

Array 16 further is equipped with additional buoy or buoyancy aid 52 in the zone of its front end 24.More particularly, this other buoyancy aid 52 is connected to towing cable 18, on outermost towing cable, is connected in waterproof photoelectricity " T shape " connector 54 places between the two segment elongations part of outermost towing cable front end 24 respectively, thereby is pulled by towing cable often.Float 52 can be identical with tail buoy 46 basically, is equipped with separately signal generator 56 and gps receiver 58, and separately elongated portion 60 is connected to their connectors 54 separately again.Though for the sake of clarity in Figure 1A, float 52 is shown as the towing cable that departs from them, in fact they basically with towing cable 18 on same line.

Focus 16 also is equipped with gps receiver (by numeral 62 expressions) and acoustic receiver, as wave detector in the water 21.Focus 16 can turn to by steering gear 17, as the steering gear of describing in the U.S. Patent application GB0307018.2 that authorizes the assignee of the present invention number.

In use, lay focus 16 and earthquake towed cable array 19 and be configured to about 5 nautical miles/hour speed substantially as shown in Figure 1A and 1B from ship 11 and pull them.Earthquake source 16 is igniting periodically, and once the reflection seismic data-signal that is caused was detected by wave detector 21 in the water in the towing cable 18 in for example per about 10 seconds, is digitized then and is sent to system 14 in the ship 11 via lead-in wire 20.

Though focus 16 and towing cable 18 are shown as after ship 11 and extend along perfect straight line in Figure 1A, in fact owing to wind and influences such as wave action and current, they often are subjected to transversal displacement (as described further below such).Like this, represent,, determine that accurately wave detector 21 position (being latitude and longitude) separately is vital in focus 16 and the water for the each blast that produces by focus in order to constitute in the measured subterranean zone position accurately on stratum.For focus 16, typically use gps receiver 62 and finish.Wave detector 21 position separately is with respect to one or more gps receivers 50,58 and 62 in the water, determine by triangulation, this triangulation is used sound ranging and is carried out based on the positioning system of signal generator 40,48 and 56, wherein signal generator 40,48 and 56 with a selected water in wave detector 21 combine operation, as authorize assignee of the present invention's United States Patent (USP) 4,992,990 and 5, as described in 668,775.Like this, once complete seismic surveying not only causes a large amount of geological datas, also causes a large amount of position datas to provide its focus 16 of each blast and wave detector 21 position separately that produces for focus.Can determine in the whole measuring process the path that every towing cable 18 is followed or the shape of trace by these position datas (claiming aeronautical data again).

With reference now to Fig. 2,, method of the present invention comprises the step 110 of collecting the input data, the input data comprise the aeronautical data of each navigation node, from the operational state data 116 of the sensor of following the spread control element, and the environmental data 118 of this time measurement and measurement design data 120.Collected this organized input data and can be obtained and obtain from the metrical information of simulation from measure preceding information, operator's input, current measurement (in real time near or real-time).

Aeronautical data

As indicated above, can obtain aeronautical data 112 from spread 10 by a plurality of points (navigation node) being determined position, speed and three vectors of acceleration.Be designated as the audiolocation receiver along wave detector subclass in the earthquake water of towing cable.These receivers receive the acoustic signals of a uniqueness, and this signal is from transmitter in line of the common every 400m of towing cable longitudinally.Transmitter and receiver combination provide along the sound wave reference point of the common spacing of any towing cable less than 100m.As United States Patent (USP) 5,668, as described in 775.The towing cable end points is by the control of GPS reference point, and these reference point link together sound wave navigation node and geocentrical earth fixed coordinate system.Being connected between GPS reference point and the sound wave node is by realizing to the distance of known distance, acoustic measurement and by the combination of the direction of lining.The coordinate estimated value that all is used for providing with the least square regulated quantity that each demolition point is calculated each navigation node aboard ship of these measurements.

The precision of the density of these navigation nodes and location estimation value is enough to provide overall and one of the spread parts part suitable picture.These aeronautical datas are the tolerance of the position response of spread 10.Three vectors based on navigation can also be used to calibrate this machine inertial navigation unit.These these machines can provide accurate position, speed and acceleration estimation value to the spread control system, allow this system compensation himself, the calibration frequency be higher than the frequency that obtains sound wave network site updating value.The navigation updating value also is useful for calibration inertial device itself, and these inertial devices are subjected to the influence of cumulative errors (so-called drift) usually.Hereinafter will discuss calibration in more detail.

Mode of operation

Follow the sensor of spread control element to be used for producing the operational state data 116 that the input data are collected, these sensors comprise one or more in the sensors such as tension force, flow rate, vertical bank, body orientation, acceleration, speed and position.In one embodiment of the present of invention (hereinafter describing), these sensors or measurement mechanism provide input to fluid dynamics spread model, and this model is used to describe the dynamics of spread 10.

One group of operational state data is subordinated to ship 11.These states comprise the motion (being racing, pitching and inclination) of ship's head, speed, rudder angle, airscrew pitch and ship.The change of these states will cause the change at the horizontal and vertical coordinate of ship 11 afterbody towpoint positions.

Another group mode of operation is relevant with

steering gear

17,22 and 38, is described in the water velocity on the rising body (as the deflector fin).Sensor provides the orientation (as the orientation with respect to good route) of device 22 and the water velocity on the rising body.Sensor gives wing angle and the wing angle relevant with current changes.

These modes of operation can be converted into the power that is applied by steering gear.These power are distributed on towing cable 18 length directions or link to each other with point on the focus array, and they are opposite with acting on by the force direction of towed body surf zone of causing of water, and the sum total of (the gun array floating thing for example is also referred to as sausages) these power provides:

1, from the initial towing cable shape of towpoint (initial point);

2, source center; And

3, single focus array is with respect to the position of their ship towpoint.

Tension force on the trailing cable is another important mode of operation, and it is the input of hydrodinamical model in one embodiment.This mainly is the function with respect to water velocity that is fixed on the body on the tensiometer and resistance.In addition, tension force is used for determining whether tow line has reached their limit, the size of the power that this limit restriction will be applied by steering gear.

The length of the trailing cable that the winch counters report is laid, it and SFED power make up, and determine the orientation of spread front end.

These and other operational state data is capable of being combined in the power model, provides the force vector of determining by towing spread component shape.Hereinafter will further be described with reference to spread model (as the power model).

Environmental data

The environmental data of collecting in the input data 118 comprises one or more data types in the data such as current, salinity, temperature, pressure, the velocity of sound, unrestrained height, unrestrained frequency, wind speed and wind direction.

The preceding tidal flow table of the seismic surveying of using several sources to announce can be predicted the tidal flow that this is regional.These sources comprise British Admiralty, National Oceanic and Atmospheric Administration (NOAA), the hydrology and ocean service organization (SHOM).For the zone that is considered to strong tidal flow, measure route and will be timed to and the low consistent time of time of flow section.The time period of high current will be used for other measurement activities as much as possible, as return and sailing into.

Have again, can look back this regional seismic surveying history, to be identified in the plum grape number of degrees that this measurement zone experiences in history.Can in database, carry out the plum grape statistics, for using thereafter.Plum grape is a kind of indirect measurement to current in the measurement zone.This measurement can be used for pointing out size, direction and the change in time and space rate of these zone current.Spatial frequency is relevant with towing cable length.By " the good speed " of towing cable afterbody rate of change with plum grape is associated, plum grape can provide an indication of spatial frequency.The rate of change of plum grape will make the schemer of measurement that there is a understanding the needed response time of spread control system that they are determining.

Time quantum in the earthquake data acquisition process is demolition point normally.So the long time cycle can be defined as the demolition point of following a certain quantity, it is corresponding to the time span that can keep the current environment condition.

As an example, in the operation of morning and evening tides section, know and know the cycling time of tidal flow.Planned the seismic line that continue 15 years at least, obtaining identical current or time of flow gradient being arranged, thereby reduced level of encryption along adjacent survey line.Some seismic prospecting software suppliers provide the seismic surveying route planning software so that consider the time and the spatial variations of current during earthquake data acquisition in advance.

In addition, can look back any available historical water flow data, with the identification direction of strong current.If the geophysics target allows, line direction preferably plans to become to be parallel to main water (flow) direction.This will provide minimum plum grape and the most straight towing cable.These class data can obtain in the Petroleum Production zone of maturation, because the there needs current knowledge to be used for the running of piercing drill and floating production, oil storage and emptying (FRSO) system.

Can obtain the flow measurement during some water flow data measurements source is used for seismic surveying.Be installed in acoustic doppler current bottom profiler (ADCP) on the hull and measure current at focus array and spread front end the place ahead hundreds of rice.Be installed in that the current meter on the semipermanent or fixed sturcture (for example being installed in the piercing drill and the FPSO in seabed) can be via telemetry link in real time to the local current of ship 11 reports in the measurement zone.Work or boarding ship or any other moveable platform, comprising can remote-operated ship (ROV), if the flow measurement device is aboard ship arranged, then can be along measuring trace in current district that spread 10 these spreads of the place ahead remote measurement will run into.Satellite imagery provides the knowledge about the hot water vortex of macroscopical circulation.

Total data source about current is stored in Geographic Information System (GIS) database, and has time mark.This type systematic generally is used to manage the data of space distribution.An example is a class data management system of being used by Horizon Marine.For short time period, these data can be thought effectively (for example one hour or shorter).Based on the historical variations that the whole data collection process observation arrives, can derive the variation tendency of long period section, be used for considering in advance the situation on the adjacent survey line.Have again, can calibrate the current component (as indicated above) by the morning and evening tides driving of prediction based on the in-site measurement result.If know the frequency content of tide signal, then can proofread and correct amplitude and phase shift, to be adapted to the accurate place of this seismic surveying by the tables of data prediction.

At the scene, can with current countings according to handle the windage scale data that measuring instrument on the above-mentioned same platform that is used for flow measurement or sensor obtain just the samely.Certainly, these data are to be used for predictive role power of object on the sea is set up model.In addition, windage energy translational surface water layer causes wind-driven surperficial current.The influence of wind-driven surperficial current can reach several meters dark, this is the current depth areas that is used for towed streamer.

The dynamics ocean model of ocean water body as those models that Horizon Marine provides, can be used to predict various oceanographic phenomenas.These models are equivalent to the weather prognosis model substantially, and their prediction accuracy is similar each other as the function of time.These models need inputs such as flow measurement value, also need the data of wind to be used for the calibration and the boundary condition of model.Two main drivers of these models are water-mass density difference and earth movements (being Coriolis force).Density difference is derived by temperature, pressure (degree of depth) and salt degrees of data, these data with discardable or callable probe in level to passing measured zone and vertically to passing the water column collection.These data provide density interface figure, and it moves relative to each other the water body of different densities with earth rotation, wind and other power.The place of vertical density gradient maximum is on the upper strata, this is because the heat effect of the sun, also have the place near land, the water that is derived from land there enters marine, and vertical there land piece makes the water body of different densities change its place degree of depth (gushing as on longshore).

The dynamics ocean model is well-known, but (being that its zone is than the big manyfold in seismic surveying zone) of macro-scale often.The raising of computing power has in recent years caused developing and is suitable for having a mind to the model of water sports in the estimation range, free burial ground for the destitute with the yardstick in seismic surveying zone.Pickard and Pond dynamic oceanography draw the opinion in typical numerical model has been described.The prediction that uses a model is obtained the method for the current that a spread of seismic measurement data will run into and can be used at the scene, to consider current in advance.On-the-spot measurement to current and wind also will be used to calibrate the ocean model predicted value.The density measure with the horizontal direction expansion of higher frequency causes the more high resolving power on water body border and the simulation and the calibration of improvement.

Above-mentioned current are determined any subclass of method, no matter be the simulation that has after the calibration of any degree, or without the simulation of calibration, and directly measure, these all are valuable to earthquake data acquisition, thereby because it can reduce data acquisition time by increasing the production time.The old more then use value of data is low more.The current information that obtains (in real time near and/or in real time) will be used to estimate the power that will run into along the data acquisition circuit.

Above-mentioned being collected in the present and the future and all will being used to estimate in the whole spread propagation to the water-mass density data as acoustic wavefront between the focus of navigation node and the receiver point.

Estimate to obtain unrestrained high measurement value by statoscope and high frequency GPS vertical speed by satellite imagery and scene.The change of water body position records influence to earthquake, and this fact causes the requirement that SSD is proposed to keep the degree of depth.The wing angle that takes place for controlling depth changes influential for the horizontal steering capability of steering gear.Current, Q-FIN ^TMThe SSD controller is combined level and perpendicular positioning.The high knowledge of wave helps to determine available horizontal steering capability when the operation towing cable.The wave height provides the tolerance that water particle passes the water body three-dimensional motion.This is small scale current on effect.The wave high-amplitude will determine whether the current in the towing cable degree of depth are a significant power.

The input data aggregation

Preferably, data comprise the environmental sensor data before the seismic surveying of collecting in the input data.That part of input data 110 of collecting as real-time measuring data can comprise one or more data types in cable stretch, flow rate, inclination, orientation, acceleration, speed, position, the setting of spread control element, environmental data, seismic signal and the data such as noise data and operator's input.Collected position data can comprise the data from one or more sensors in one group of sensor such as gps receiver, echo sounder, depth transducer, acoustic ranging system, magnetic compass, gyrocompass, radio positioning system, accelerometer and inertia system.The spread control element is provided with data can comprise one or more input data in one group of data such as thruster setting, airscrew pitch, revolution speed of propeller, rudder angle, towing cable cable stretch, winch position, deflector orientation, deflector angle, deflector water speed, towing cable steering gear orientation and towing cable steering gear wing angle.

The original seismic sensor data of collecting during seismic surveying also can be characterized as being the input data.So in one embodiment, method of the present invention further comprises the step of using original seismic sensor data to be created in the quality indication of the local current of towing cable surface estimation.Original seismic sensor data are useful for the power of confirmation model and expection current.Neighbourhood noise neighbourhood noise of measuring and prediction or expection compares, and neighbourhood noise prediction or expection once was used to provide the expection current on towing cable surface.Big difference between noise expection and record is pointed out the different of the wrong or current of register system and expection.Neighbourhood noise provides the spatial gradient of current along the variation of towing cable length direction.The quality indication can comprise bin data set, absolute noise data, signal noise ratio and seismic signal frequency content.The quality indication can be used for confirming the validity of real-time measuring data.

The seismic surveying design

Collect the seismic surveying design data of input in the data and comprise one or more data types in zone, the degree of depth, seismic section operation orientation, survey line coordinate, focus and the data such as receiver position, required coverage, restriction, the optimization factor and historical data.It will be understood to those of skill in the art that seismic measurement data further comprises spread performance index 114, as described below such.Seismic measurement data can also be characterized by spread target and restriction, can also be determined by information before measuring basically.

The seismic surveying design is a kind of adaptability design, because the geophysics target is a restrictive condition, all seismic surveying persons must work in these restrictive conditions.All aspects that will comprise a seismic surveying target are measured in general earthquake.Some geophysics target will influence earthquake data acquisition.These targets comprise:

1, the quantity of towing cable and length;

2, towing cable spacing;

3, focus array yardstick;

4, demolition point spacing; And

5, line direction

In case determine the geophysics target of seismic surveying design, identification causes the factor of difficulty and attempts to alleviate these factors to earthquake data acquisition and just becomes important.For example, if a target of this measurement is free measurement (4D) at interval, a factor that then makes the data acquisition difficulty is previous or the measurement track and the non-rectilinear of benchmark.Can obtain knowledge by reading previous " P190 " data that produce of measuring about this track.Then, these tracks can be compared by getable track with considering selected acquisition hardware.Yet if fundamental purpose is traditional covering, She Ji survey line will determine the trace of this measurement in advance.Yet for any geophysics target, local obstacle and oceanic sounding result will be the restrictions to the trace of being planned.

Above to using the description of measuring design number, spread control element index, environmental data and mode of operation to be specially adapted to the measurement that (but being not limited to) carries out during this seismic surveying.These data are imported in the general translation function 121, and it provides one group of output of wishing, as shown in Figure 2, will further describe hereinafter.

With selecting to measure the selected spread control element of designing institute, to satisfy the earthquake data acquisition requirement of expection.In addition, the trace of ship will be subjected to the restriction of seismic surveying target.Have again, during measuring, will monitor obstruction and Ocean Surveying data in the measured zone, with the degree of closeness of understanding with spread.

Performance index

It is normally fluid dynamic to be collected into the performance index of measuring in the design data 120 114, can comprise the overview of ship and feature, shipping make the limit, by the resistance of trailing cable and other physical characteristicss, the resistance that can turn to seismic source apparatus characteristic, deflector characteristic, flotation gear and other physical characteristicss and winch operating characteristic.These class single assembly performance index can obtain from manufacturer and/or from historical data usually.Except other were used, these inputs were measured with geophysical survey target limit simulated earthquake, and this is useful to measuring design, can provide tentative combination towing system performance index.Like this, for example can before carrying out seismic surveying, determine various spread demands and index, the quantity of the space frequency that distributes along towing cable as the towing cable steering gear, the turned to front end deflector that will lay, the focus that lay turns to the quantity and expection (relevant with the current gradient) required computing power cycling time of deflector.Have, this analoglike can be used to design the spread parts to improve control performance again.The examples of parameters that can change in simulation is cable size, cable density, be more suitable for cable body shape and steering gear that fluid dynamics requires.

Location estimation

After having collected the input data, can use aeronautical data 112, mode of operation 116 and environmental data 118 to estimate the position of focus and receiver.More particularly, be to come the estimated position according to the spread model 123 in the translation function 121.The spread model uses first group of estimated position of input data computation, and the input data here comprise mode of operation 116 and environmental data 118 at least.As described in Fig. 9, environmental data is used to provide the nature plum grape.A certain amount of plum grape that turns to that SSD 38 requires is added on this nature plum grape.An example that the position is estimated at the mode of operation of contribution is to turn to input/correction for realizing that desirable plum grape is needed.Turning to plum grape is to be obtained in the horizontal line direction application of force by the SSD along towing cable 18.The equation of control application of force size is based on fin lifting equation:

L = C_{1} * A * ρ * \frac{V^{2}}{2}

(formula 1)

Wherein:

C ₁=lifting coefficient;

A=flap surface area;

The V=water is for the speed of the fin angle of attack; And

ρ=water-mass density.

The angle of attack is adjustable, thereby is another mode of operation.Change that the angle of attack causes an acceleration or by integrated or be coupled in the variation of the power that the SSD of towing cable applies.

The aeronautical data of collecting 112 comprises second group of estimated position.A subclass along wave detector 21 in the earthquake water of towing cable is designated as the audiolocation receiver.These receivers receive the distinct acoustic wave signal from transmitter in the line, place such transmitter along the every 400m of towing cable usually.As United States Patent (USP) 5,668, described in 775, the combination of transmitter and receiver provides sound wave reference point (being navigation node), usually along any towing cable less than being separated with such reference point between 100m.The towing cable end points is by the control of GPS reference point, and these GPS reference point link together sound wave navigation node and geocentrical earth fixed coordinate system.Being connected between GPS reference point and the sound wave node is by realizing to the distance of known distance, acoustic measurement and by the combination of the direction of lining.The coordinate (second group of location estimation value) that all is used for providing with the least square regulated quantity that each demolition point is calculated each navigation node aboard ship of these measurements.

First group and second group of estimated position combine (seeing node 122) in translation function, produce (combination) focus and receiver estimated position and prediction residual (seeing frame 122a).Prediction residual is represented the poor of first and second groups of estimated positions, is used to estimate one group of parameter that characterizes spread model 123.The spread model parameter is used to calibrate the spread model.Prediction residual can be further used for estimating to collect the employed sensor errors state of environmental data.

Determining of best trace

Best trace is determined in frame 124 according to weighting function 125 in translation function 121.Weighting function accept seismic surveying design data 120 and focus and receiver nearest estimation the position as the input (seeing frame 122a).Can comprise the performance index of spread control element from the input of seismic surveying design data, as turn to restriction.Other seismic surveying design datas comprise requirement geophysical and operation.Geophysics requires to comprise and for example reaches the seismic signal raypath that desirable subterranean zone covered or repeated previous measurement, and control seismic sensor noise.The operation requirement for example can comprise determines one or more escape way for spread passes the hazardous location, determines to finish the Best Times of one or more measuring circuit, and reduces unproductive time.Weighting function 125 is used for relative weighting coefficient is applied to input, calculates its best trace for translation function for this spread.The determining of " best trace " comprises determines best spread shape and along a corresponding change of shape of trace.

For the target that realizes that one earthquake is measured, must occupy certain group coordinate (i.e. " trace ").First estimated value that desirable or " the best " measures trace provided in the above-mentioned measurement design phase.At the scene, according to current power and navigation update frequency, will recomputate this trace with a certain frequency.Even carry out recomputating of best trace, drive the response time that order will taking into account system when realizing this best trace best sending with high frequency.In the zone of weep, measure the trace of determining before design trace or the measurement and can realize not having or have only very little influence for the spread control system.In other zones, the high frequency that then may require to carry out the optimum cost trace recomputates.Have only when navigation is upgraded the result and disclosed prediction success by the spread model-driven, could realize recomputating.Only upgrade the result and show that the track of prediction has departed from trace and surpassed possible error boundary (being also referred to as constant corridor), just need recomputate in navigation.

In fact, the physical restriction that is given by the combination of the nature and the steering limit will prevent to follow to a certain extent the trace that designs before the measurement of wanting mostly.Consider the object coordinate when determining the path and control the ability that potential ability is issued to this coordinate at given spread.

In an embodiment 124 of calculating optimum trace, utilized United States Patent (USP) 6,629, the optimum cost ground drawing method of No. 037 description, this patent authorizing assignee of the present invention.Candidate unit in succession (trace segments) is by a function weighting, and this function has comprised the combination of a plurality of factors, and these factors are characterized as being usually and turn to restriction.These factors comprise:

1, trace before the measurement of whole spread parts;

2,, be similar to the skew weighting among the Nyland to the differentiation of spread parts importance;

3, the available potential ability that turns to;

4, the response time of system;

5, the stability of system; And

6, the physics limit of system.

Best trace is being sent to the spread model with before converting the driving order that will realize best trace to, the possibility that check this trace and spread element and outer barrie to bump.The safety criterion of best trace comprises that the track of any spread element of affirmation (seeing frame 127) does not have the danger of collision."No" result will cause by GUI to field feedback: or turn to limiting parameter that correct or optimized algorithm defectiveness are not set.So the user can select steering is carried out manual control or modification turns to restrictive condition.Modification turns to an example of restrictive condition to be: if surpassed the at interval limit of towing cable, then the user can to select to allow towing cable to move to more close each other.Another example is, if a spread element (for example tail buoy) will move to too near a barrier, as floating production, oil storage and unloading system (FPSO), then the user can select to make FPSO to change the position and it is sent into measurement design data stream, thereby can realize best trace safely.

The "Yes" result that this safety inspection is provided will cause determined best trace is submitted to spread model 123, be used for the new mode of operation (promptly driving order) of compute spread control element.

The calculating of driving order optimization causes one group of driving order---mainly being directional commands---, and this will bring the change of spread component locations, as the part of translation function 121.Environmental baseline that the driving order optimization will be scheduled to and the constraint that can be used for starting orienting device.The definition that drives order optimization will be determined by best trace.

Drive the calculating of order

Driving order (being also referred to as new mode of operation here, is the result by determining that best trace produces) is to use the best trace (by frame 124) of the confirmation of determining (127) that at least two spread control elements are calculated in spread model 123.The spread response time is estimated by the spread model, and is considered when calculating the driving order.Also to regulate driving the stability of order, and before sending to the spread control documents, confirm its validity (128) with the maintenance spread.

Each that utilize that method of the present invention calculates drives at least one among one or more position component, speed and the working direction three that order can be used for controlling this spread.Typically, drive these central at least one of the steering gear of thruster that order will comprise the screw propeller of control ship, ship, spread parts and ship reel truck.Particularly the ship reel truck can be subjected to dynamic control.

The calculating of driving order optimization causes one group of driving order---mainly being directional commands---, and this will bring the change of spread component locations, as the part of translation function 121.Environmental baseline that the driving order optimization will be scheduled to and the constraint that can be used for starting the steering gear that turns to.The definition that drives order optimization will be determined by the target that drives order.

The optimization criterion comprises the driving order that any one group of mechanicalness of affirmation (seeing frame 127) is brought out or is to realize that the variation of the needed power of determined best trace is in the safety requirements scope of this seismic surveying.Usually, these safety requirements are one of device security restriction and personal security restriction.The "Yes" result of safety verification will cause determined best trace is submitted to exhibition step model 123, be used to calculate the new mode of operation (promptly driving order) of exhibition step control element.Like this; for example in case detect some spread control assembly lost efficacy (as screw propeller or rudder, deflector, focus or the towing cable steering gear of ship); then system will present a kind of " maximum security " mode, and this will limit for protection equipment and personnel and drive order.

Determining of potentiality

The potentiality of spread control are measured by spread model 123, and in this preferred embodiment, the spread model is a hydrodinamical model, and it determines to cut the size of operable power after the power that this blast cycle consumed from total potentiality.Although turn to potentiality from can exert oneself, to derive, can represent (as degree or any other measurement of angle unit) with the unit of plum grape.Depend on and measure design (target that comprises data acquisition), will analyze, if desired, will determine that also which kind of order is suitable to determine whether to need to change driving order.According to definition, power has an acceleration part.System performance comprises the available potentiality that turn to, and is power driving model and common prediction of spread control element driving order that should provide necessary acceleration by theory.

The historical relation of time-delay, system responses and position and error state

As mentioned before, estimate that with the position history that derives from the navigation result (second group of estimated position) compares, and forms the residual error of prediction by the position history (first group of estimated position) of spread model 123 predictions.Then, prediction residual is related with error state, power model parameter and the spread control element performance index of definition in the input of power model.In a free from error model, predicated response will take place on time, and in other words, system delay will be considered in the response of prediction.This model is learnt system responses from the navigation result before, by calibration, model prediction will have error to a certain degree, and its error size depends on the quality of model and input.

Before the history that can obtain comparison, will ad infinitum be higher than position history based on the power model based on navigation result's the weight of history (second group of estimated position).Actually, this means that the navigation of combination and forecast model location estimation equal navigation and estimate, almost all prediction residual all by owing to the spread model.After this model was calibrated, the power model expectation value of position history should be with historical consistent based on the measurement of navigation, in the error desired range of values of location estimation value that measure or the navigation result.

Drive the calculating of order

Driving order (being also referred to as new mode of operation here, is the result by determining that best trace produces) is to use the best trace (by frame 124) of the confirmation of determining (127) that at least two spread control elements are calculated in spread model 123.The spread response time is estimated by the spread model, and is considered when calculating the driving order.Drive and order the stability that also is subjected to regulating with the maintenance spread, and before sending to the spread control element, be identified its validity (128).

Drive normally will determine of order according to geophysical and operation.Geophysics requires to comprise and for example reaches the seismic signal raypath that desirable subterranean zone covered or repeated previous measurement, and control seismic sensor noise.The operation requirement for example can comprise determines one or more escape way for spread passes the hazardous location, determines to finish the Best Times of one or more measuring circuit, and reduces unproductive time.Therefore, can also calculate other and drive order, be used to make the escape way between two or more definable positions to come into force.

The present invention's other application except that real-time measurement

Another effect of the present invention is to provide " intelligence completion " or scene plan to the operator.Operator's translation function 121 expression is to 2 or the basic idea of a paths between the multiple spot more, and this module is then assessed out the different escape ways that fall in the spread steering capability scope to whole spread, and shows them the operator selective.This can be used for when needs when special time arrives the locality.Another application is when the shortcut that needs a safety owing to operational reason arrives permanent or a semi-permanent structure or a characteristic body.

Intelligence completion uses same extrapolation side's method to enter future, is different from restriction in measurement environment but be added to restriction on the conclusion.What emphasize in this case is safety and hours underway, rather than guarantee in the spread each discrete component all strictness follow predefined path.Has the zone that forbidden zone regulation discrete component should not enter.The extrapolation time is longer usually, and the received uncertainty of energy is bigger in system.Which scene the operator selects to accept in this case.

Another application of the invention is to be used to develop simulation system.The actual input data of operation in translation function 121 with steering gear of developing.The improvement in performance of expection is used to measure the improvement result of the steering gear of exploitation.

Based on the target of steering, can calculate the trace of ship, the trace of towing cable front end, the trace of focus and the plum grape of towing cable, to provide the best located of the spread that drives by the spread control element.Hereinafter will use the example of a power model, describe this computation process in more detail as spread model 123.

Use general introduction

Following table is showed the representative instance according to the optimization criterion of broad sense measuring period.

Incident	Precondition	Target	Output	Restriction
Incident	Precondition	Target	Output	Restriction	Premeasuring	Do not have	Assessment covers the measurement of carrying out with minimum ship number of pass times and with required bin	Measure the section production plan	That avoid damaging oneself or other people equipment
Premeasuring	Do not have	Determine the feasibility successfully measured in the given area	The worst case error ellipse; Important risk factor; Required spread control element or required system; The maximum possible working direction changes	Keep system stability	Premeasuring	Do not have		Measure the section production plan	That avoid damaging oneself or other people equipment
Premeasuring	Do not have			Keep system stability	Measure	The current state of measuring	Finish measurement with minimum ship number of pass times and with required bin covering	Measure the section production plan	That avoid damaging oneself or other people equipment
Measure	All gearings are in water; Be ready to the section operation	Move to the starting point of next time walking from current location	Ship and equipment turn to plan	That avoid damaging oneself or other people equipment	Measure	The current state of measuring		Measure the section production plan	That avoid damaging oneself or other people equipment

Incident	Precondition	Target	Output	Restriction
Incident	Precondition	Target	Output	Restriction	Measure	All gearings are in water; Be ready to the section operation	Move to desirable position from current location	Ship and equipment turn to plan	That avoid damaging oneself or other people equipment
Measure	All gearings are in water; Be ready to the section operation	According to original section production plan control ship and other spread control assemblies	Send to the driving order of spread control assembly.	Observe predefined secure border	Measure		Move to desirable position from current location	Ship and equipment turn to plan	That avoid damaging oneself or other people equipment
Measure			Send to the driving order of spread control assembly.	Observe predefined secure border	Laying/withdrawal	All/the part gearing is aboard ship	Lay a towing cable	Ship and equipment turn to plan	Make risk minimization
Laying/withdrawal	All/the part gearing is in water	Regain a towing cable	Ship and equipment turn to plan	Make risk minimization	Laying/withdrawal	All/the part gearing is aboard ship	Lay a towing cable	Ship and equipment turn to plan	Make risk minimization
Laying/withdrawal	All/the part gearing is in water	Regain a towing cable	Ship and equipment turn to plan	Make risk minimization	Laying/withdrawal	All gearing is in water	Towing cable is safeguarded	Give the steering order of work boat; The towing cable order that towing cable instruction help is safeguarded	Make risk minimization

Incident	Precondition	Target	Output	Restriction
Incident	Precondition	Target	Output	Restriction	Change index, conditions and environment	The current state of measuring; Change	Finish measurement with minimum ship number of pass times and with required bin covering	Measure the section production plan	That avoid damaging oneself or other people equipment
Lost efficacy	The propulsion system of ship lost efficacy	Repair propulsion system	All control system are set to home	Make the maximization of equipment and safety of persons	Change index, conditions and environment	The current state of measuring; Change		Measure the section production plan	That avoid damaging oneself or other people equipment
Lost efficacy	The propulsion system of ship lost efficacy	Repair propulsion system	All control system are set to home	Make the maximization of equipment and safety of persons	Lost efficacy	Deflector lost efficacy	The deflector that repairing/replacing was lost efficacy	All control system are set to home	Make the maximization of equipment and safety of persons
Lost efficacy	Ship turns to inefficacy	Repair steering gear	All control system	Make equipment and people	Lost efficacy	Deflector lost efficacy	The deflector that repairing/replacing was lost efficacy	All control system are set to home	Make the maximization of equipment and safety of persons
Lost efficacy	Ship turns to inefficacy	Repair steering gear	All control system	Make equipment and people				System is set to home	Member's security maximization
Lost efficacy	The focus steering gear lost efficacy	Repairing/replacing or disabling device implemented fail safe	All control system are set to home	Make the maximization of equipment and safety of persons				System is set to home	Member's security maximization
Lost efficacy	The focus steering gear lost efficacy		All control system are set to home	Make the maximization of equipment and safety of persons	Lost efficacy	The towing cable steering gear lost efficacy	Repairing/replacing or disabling device implemented fail safe	All control system are set to home	Make the maximization of equipment and safety of persons

Table 1: optimize criterion

So, can calculate other driving orders each spread track is come into force.

Translation function

As mentioned before, translation function 121 is carried out the location estimation of the inventive method, best trace is determined and drive order calculation procedure 122,124,126.The input that spread model 123 was also mentioned according to preamble produces the location estimation value and/or the spread shape of first group of prediction in advance, upgrades until navigation next time.This group predicted value and navigation system location estimation value (second group) combination, focus that obtains making up and receiver position and/or shape are estimated.The residual error (first group with second group poor) of prediction is used to estimate some key parameter and any error state related with environment measurements such as current or wind of spread model.Combined location estimates to be sent to best trace algorithm for estimating 124 and weighting function 125.

Resulting spread model parameter is fed to spread model algorithm 123.Have, environment measurement error state estimated value is used as calibration value and feeds back to environment measurement device (seeing frame 118) again.

Preferably, best trace is to determine at 124 places according to the weighting function in the translation function 125.In a specific embodiment, weighting function reception measurement design data 120 (comprising performance index) and combined location estimated value are as input.Weighting function is estimated by block position and each value of measurement design data 120 (particularly comprise and turn to restriction) is given relative importance or weight, to derive the best trace or the shape of this spread." the best " in this sense is as far as possible closely to satisfy to turn to restriction and seismic surveying target under the situation of given current spread location estimation.

Except aforementioned power model, the spread model can be driven by the pure statistical model of spread parts, this model can be a closed-loop control system (based on the PID controller of a mechanical model) as describing in International Patent Application WO 00/20895, a nerve network system, perhaps it can utilize one of L-norm match criterion to go to estimate the behavior of spread.In fact, any estimation theory method that is suitable for optimal coordination one cover spread control element all can be applicable to realize the desirable trace of all or part of spread.For the situation of neural network, the spread model is followed United States Patent (USP) 6,418, the instruction of 378 (using " snapshot " training pattern of spread coordinate).

If translation function determines that (frame 124) needs or wish remarkable different a spread shape or a trace, then check or confirm that this spread changes by an internal security check (seeing frame 127).

If safety verification determines that trace or shape that this is new are safe ("Yes"), the spread control element coordinate set or the shape description that then will constitute the new best trace of estimating are presented to spread model 123 to obtain suitable driving order correction.As the next step of optimizing for example, determine to order which or which controllable device.Initial ranging is to use following principle to carry out: by the device of being ordered be can influence all overstep the extreme limit or the chain of undesirable condition in be in that device of extreme lower position.Like this, if towing cable array 19 and focus array 16 leave the position in same direction, then change the position of ship 11, the position that promptly changes " father " towing gear is optimal strategy most likely.If towing cable and focus array leave the position in opposite direction, then the control that each subsystem is changed separately may be best.Use the previous relation of setting up to calculate a kind of best change, for example, the direction of rudder changes 1 degree may on average make 0.1 meter of ship transverse movement in the kind at 5 seconds.

Then, for confirming its validity, this change line time extrapolation of being marched forward, with check be at least corresponding to the time period of next update cycle on this change to the influence of whole spread.If this influence is undesirable, then sets up the another kind combination of these control variations and repeat its extrapolation process.No matter to the spread control element can with turned to which the restriction, always the diversion order of one group of definable optimization is arranged.May be without any changing the original definition that can on the extrapolation time period forward, realize those results best or that wish.In this case, make amendment, thereby search realizes desired result's change at maximum duration Duan Shangneng the definition of " the best ".

If internal security check 127 determines that the best trace that calculates is unsafe, this "No" response feeds back to the operator by graphic user interface (GUI) is online.So being apprised of the trace component that exceeds the safety inspection limit and being prompted to revise, the operator measures design to eliminate in violation of rules and regulations.This may need some impact point weighting again along reference measurement.The operator can select to take manually to turn to guaranteeing to the control of system and to the period that mistake turns to and not have an accident.

Usually, when the needs timing, the correction that always has two classes to carry out: a class be by problem area or in problem area the place ahead (upstream) thus changing control removes source error; Another kind of is the propagation of removing error or problem by (downstream) change control after problem area.

When selecting to drive the best trace of ordering after realizing safety verification, drive orders itself at 128 pairs and carry out validation verification by spread model 123.This is a fail-safe mechanism for driving the command selection algorithm.If drive order by checking ("Yes"), they will be sent to the spread control element and remove to implement (seeing 130).

If drive order not by verification step ("No"), then the operator is apprised of the algorithm failure once more and can selects to take manual control or revise to constitute and turns to one of parameter of restriction.

The translation function circulation can be carried out under the situation that can obtain the permission of aeronautical data and computing power as far as possible continually.The another kind of practice is that this circulation can not carried out so continually, but sends the driving order consistently again by the spread model, and these orders will make spread adhere to optimum shape or trace that most recent is determined.

As time goes on, a best spread model by calibration development, this comes down to a learning process, is that the position history that will measure is exported with the model of expection and compared.This model will change according to the equipment in the spread and prevailing ocean and weather condition.Spread model 123 obtains one group of coordinate of spread parts to determine the starting point in this model.According to leading ocean condition and the influence of spread control element and other factors of mentioning here of current and morning and evening tides, make up the dynamic model view and calibrate or train this spread model then.Realize system calibration by the relation of setting up between systematic parameter and the prediction residual.The reason that the spread parts coordinate of prediction changes will be always because at least one factor in the factors such as the change of spread control element mode of operation, ocean current and nearly surface wind.Water flowmeter and windage scale are directly measured and can be known natural force, and can infer out by the spread component variation of navigation scheme measurement or by the model prediction in ocean and/or the weather forecasting model (as by the available model of Horizon Mrine).

Chronistor is drawn

In the zone that is produced appreciable impact by highly deterministic and predictable phenomenon (as tide current), these inputs are used in the time that reaches some months before the actual measurement time and produce one group of best diversion order.Can use the spread model parameter of calibration that spread model 123 is carried out the forward direction extrapolation then.

Best trace to plan carries out real-time regulated

During carrying out seismic surveying, according to morning and evening tides or other current, can be based on best trace being adjusted along the physical location of measuring the route realization.When the actual path of being realized is within the trace limited range of plan, then do not change.Constant corridor limit is from the error estimate of following combination focus and receiver location estimation value and thinks that providing turning to of optimum limits the two derivation.Can carry out this check to each circulation of translation function.

If track is fallen outside, constant corridor, then need to proofread and correct, so process is transferred to next stage.This next stage is to occupy this constant corridor or certain other corridor again, perhaps be narrower corridor, but it is centered close within this constant corridor.An example that remains on the method in the constant corridor is by the spread control element being carried out PID control.If realized constant scene, then this scene is analyzed to the mode of extreme variations, to find whether to wish a correction.Ideal results is the scene that remains on two intermediatenesses between the acceptable fault-tolerant limit.

The translation function general introduction

Briefly, the main effect of translation function 121 is to obtain all available input data 110 and convert them to be used for the spread control element driving order, with the measurement target that realizes selecting.Even go to be close to ground adaptation requirement although have a plurality of possible solutions, translation function will be calculated it when this scheme is used for future, can not cause undesirable effect in the time in future with the diversion order that guarantees to make now.For example, this time may be the duration that whole spread passes a given position.In each cycle period, input is admitted to translation function 121, and its reappraise current mode of operation and to any demand of one group of new optimum operation conditions includes but not limited to diversion order, and calculates its regulated quantity where necessary.

Calibration

As previously mentioned, preferably, use the spread model parameter estimation value that obtains based on aeronautical data 112, spread model 123 is calibrated according to the residual error of prediction and/or the behavior that measures.Like this, calibration has utilized the output of available measurement, as the position of using additive method (as sound wave network or GPS) to obtain or estimate, any single or a series of without the translation function circulation of calibration before and train the spread model afterwards.

Preferably, this calibration steps comprises: by estimating the spread model parameter consistent with the location estimation value, make the difference between the prediction residual reach minimum.By this way just may the feedback position quality information.Thereby can improve accuracy to the contributive spread control assembly of position forecasting process.The spread controlling models parameter that may be calibrated comprises: by the resistance coefficient of towed body, lifting coefficient, current meter error, windage scale sum of errors mode of operation deviation.Calibrating these parameters will make the difference of trace (preassigned) and track (reality) coordinate diminish.

By on mathematics, the parameter of fluid dynamic or other typess of models and the observed reading of this model of driving being associated, can realize this minimizing.At marine flow force and wind-force across the sea is power state extraneous or nature, and the mechanical resistance that is produced by the spread control element then is used for spread is carried out best located.

By the performance example that behavior is calibrated to spread that measures is plum grape after the turning to of being realized.When given desired side force scope from SSD 38, then can measure turn to the back plum grape scope as output.This output is unique for local streamflow regime and towed spread.Can predict the various plum grape that towing cable is turned to, and can realize them in the nearest past as them.Like this, the SSD response obtains calibration.Similarly, the energy measurement realization is various to turn to back plum grape required time, and can use it for to be predicted as and realize that the needed plum grape of best towing cable target shape changes.

The desired side force scope that can obtain from any spread control element all is limited, and is particularly all the more so under the situation of normal data collection (almost straight line towing).For this reason, a little subclass of the whole function of null response when only needing to describe total system is used to predict that desired under normal operation this little increment changes.

Another kind of way is that the mathematical model match can utilize the pure statistical model of spread parts.Other examples of mathematical model match step can comprise one of L-norm match criterion, PID controller, Kalman filter or neural network or these combination in any.

System

On the other hand, the invention provides a system, be used to control seismic surveying spread 10.Preferably, this system is positioned on the ship 11, but it will be understood to those of skill in the art that, one or more parts can be positioned at other places, as another ship or on land, as the telemonitoring of one earthquake being measured from bank base office, according to available message transmission rate, it can comprise part or all of translation function calculating.This system comprises a database and a set of computer-readable medium that is used to receive input data 110.Wherein contain the executable instruction of computing machine that collective realizes translation function 121 described herein.Like this, first computer-readable medium has computer executable instructions to be used to utilize aeronautical data 112, mode of operation 116 and environmental data 118 to estimate the position of focus 16 and receiver 21.Second computer-readable medium has computer executable instructions to be used for utilizing part to import the best trace that data 120 are determined (comprise at least and measure design data 120) focus 16 and receiver 21.The 3rd computer-readable medium has computer executable instructions to be used to utilize a definite best trace to calculate the driving order that is used at least two spread control elements.These computer-readable mediums can make up or merge in mode well known in the art, for example each computer executable instructions are put on the single CD dish.Preferably, as mentioned before, drive the response time delay that spread 10 is considered in order.

Confirm

An important component part of spread control system of the present invention is to confirm that independently (step 127,128) are in the best trace of step 124 calculating and the driving order of calculating in step 126.Because a plurality of reasons are confirmed to be important, these reasons comprise:

1, guarantees the safety of ship 11 and nigh other ships;

2, guarantee that the operation to the spread control element is in the fault-tolerant scope of manufacturer; And

3, guarantee to prevent that single fault propagation from becoming expensive device losses or damage;

The affirmation process occurs in the varying level and the mode of operation.Each level of affirmation process comprises:

1, the internal consistency of all spread element optimal traces in the spread 10;

Is a. Yu Ce position change in the close relatively limit range of spread?

Is b. Yu Ce rapid change in the limit range of spread relative velocity?

Is c. Yu Ce position change near in the limit range of degree at barrier?

Is d. Yu Ce rapid change in the limit range of relative barrier speed?

Is e. prediction result tension force in the tension limit scope that allows?

2, driving command parameter will be in being suitable for the limit range of particular manner of operation;

Is a. prediction result tension force in the tension limit scope that allows?

Are b. all deflector angles of attack in stopping limit range?

Are c. all fin angles of attack in stopping limit range?

Are d. all ship control device in the limit range that the restriction working direction changes?

3, to check its whether each other antagonism (for example when adjacent towing cable is too close, they being advanced toward each other) for the driving order that sends to device with height coupled relation.

The mode of operation of considering comprises:

1, straight line production---feature is that driving command parameter rate of change is low;

2, non-rectilinear production---feature is medium rate of change;

3, turning at non-productive period---feature is a high rate of change more;

4, lay---feature is altitude rate and does not observe some restriction; And

5, emergency condition---feature is to driving the minimum control of command parameter.

The affirmation process further comprises the checking system limit, for example:

1, the control limit that does not surpass the spread control element---for example, rudder stop end points;

2, do not surpass the environmental sensor limit---for example pull in tension force, the shallow water area and slip into towing cable;

3, the spread control element is provided with the response speed of variation---for example, if against the wind, then turn to change to have no impact to ship, if but with the wind, then have big influence; And

4, spread position component not outside a zone of acceptability territory (or not within unacceptable zone).

In normal running, the affirmation process is sent to separately spread control element controller with the control setting that allows to be verified after sure affirmation.If request is rejected, then send an alert message to the operator, this request is prevented from.The operator can take necessary compensation operation to control and to proofread and correct current situation then.

Minimum coupling model for example

Describe a specific embodiment of the present invention referring now to Fig. 3-13, it utilizes a hydrodinamical model in translation function.To independently as much as possible control the spread control element, and perhaps can carry out manual coordination by the operator.In reference vessel system, the independent as much as possible spread control element of disposing.In another embodiment of the present invention, all the spread control element is controlled by the highly integrated control system with complicated coupling model.

Ship turns to

It is the towpoint of determining towed spread body that ship turns to the effect in spread control, thereby makes them be in the optimum position at each earthquake explosion time.The response characteristic of surveying vessel (being its performance index) must be the part that the plan ship turns to algorithm.When the distance that calculate to arrive following point during, must consider the knowledge of the power that ship 11 will run into along this following path with the path of plan ship.

For controlling the influence that focus and the needed steering volume in receiver position can be subjected to reference measurement.If the reference measurement that is carried out makes the covering optimization, the flow force that then has cross stream component may make spread swing along the section production line.Particularly in traditional measurement configuration, turning to of ship is to reduce the process useful of encrypting.Yet if the reference measurement that is carried out is to make the possibility that successfully repeats same earthquake energy-ray path in following the measurement reach maximum, ship may turn to along the straight line that preplans circuit.

The purpose that depends on seismic surveying, one or more spread parts should occupy the object space along survey line.The ship path that allows to do like this can be calculated with the optimum cost ground drawing method of describing in the United States Patent (USP) 6,629,037.Hereinafter will further develop this method.

Make the decoupling zero each other of spread control element

As previously mentioned, in reference vessel system, can apply transverse force by towed spread control element.Like this, ship must be counted as and the coupling of towed spread, but the spread control element can be counted as them as being independently in reference vessel system.According to the target of system, can be pulled the spread parts to the ship weighting at one or more.In the spread controlling models to the decoupling zero of spread control element in the current best solution of believing for determining how these elements interact with the track of ship and the track of ship being impacted.

If the spread control element can suitably be controlled spread 10, make and do not satisfying localizing objects under the situation from the horizontal contribution of ship 11, then the spread control element is to a great extent practically or conceptive and ship decoupling zero.

Focus array

Focus array 16 online interior motions are determined by ship 11.Focus array retrains (as rope or importing cable 20) along the distance that laterally can move by the towing configuration.If focus array can laterally be diverted in the restriction corridor at this, and target then can realize best source location within this corridor.The some mechanism that position in this corridor are possible.These mechanism comprise:

1. extra parallel rifle string, they can dynamically provide focus array according to the degree of closeness with desirable horizontal survey line position;

2. hoister system, their control is with respect to the shuffle structure of outer towing cable cart rope; And

3. the deflector that has the controlled angle of attack on focus array.

Utilize these mechanism, the source location is laterally turned to, to provide best possible position, different according to the mechanism of using, its position and any other spread control element do not have or have only very little relation.Here said vessel 11 does not surpass 17 amounts that can calibrate of focus steering gear from the route lateral runout of design in advance, and the transverse force of array of seismic sources 16 can be considered by the steering gear 17 that uses.

Can turn to towing cable front end deflector (SFED)

For the front end that the SFED 22 that develops can laterally drive towing cable 18 is used in passage of time.The length that depends on boot segment in the cable 20, transverse movement will change the longitudinal component of single towing cable, cause one with the collective front end to depart from, and so-called towing cable front end departs from.Here there is the coupling between the vertical and horizontal, but is slight coupling.

There are some reason explanations the front end of towing cable 18 is turned to.The one, prevent that the outside towing cable front end from rotating (preventing that front end from departing from).One of the most remarkable reason that front end departs from is turning to of ship.Have, SFED turns to and can be used for along horizontal mobile towing cable front end again.At last, SFED control towing cable at interval.All these turn to target all to contribute to the location of towing cable front end, and it is the reference point that towing cable described below turns to algorithm.

Towing cable steering gear (SSD)

The SSD global controller has some modes to issue desired single or collective's towing cable shape according to its target.Constant plum grape and constant interval are two examples.

The plum grape mode

In the plum grape mode, the SSD global controller uses the towing cable front end as reference point (srp), is an initial point on effect, and is initial with respect to the desirable towing cable shape of a certain reference direction (for example preplanned line direction) calculating by this point.A kind of situation of this shape is the towing cable 18 with constant plum grape, and promptly whole towing cable has identical plum grape basically, as shown in Figure 3.Like this, by turning to a virtual towing cable, obtain desirable zero degree plum grape, the virtual towing cable here is to obtain by extending the straight line baseline from the front end reference point of towing cable along the direction that is parallel to a certain reference direction (as precalculated line direction).

Here be coupling or the cooperation between SFED and the SSD global controller.As previously mentioned, turn to so that the towing cable front end obtains correct reference point is another target that SFED turns to.

The constant interval mode

As shown in Figure 4, by comparing this mode that realizes with desirable interval apart from the distance of SSD on the adjacent towing cable.The effect of SSD is to make all towing cables keep the spacing of being imported by the user.During off-track, the cross stream component of distance is decomposed out for comparing.

Steering lock

Consider power in advance, particularly because which order (as turning to) will be the transverse force that current cause will determine provide best result.Yet, the spread control element is turned to may not can overcome all transverse forces that spread runs into.When reaching the steering lock of spread, translation function 121 is optimized the shape of spread 10 to satisfy measurement target.Best towing cable shape may be the straight line with desirable plum grape (for example seeing Fig. 3), it has local plum grape along the definition of each section of towing cable to reach the best-fit (for example seeing Fig. 5) to previous measurement towing cable shape, and perhaps towing cable may separate (for example seeing Fig. 4) equably to allow to explain better squiggle in the geological data treatment step.

Pattern of water flow in translation function

Same simple pattern of water flow (being shown in Fig. 9) at the focus array plum grape also is applicable to towing cable 18.Only current are constant to a certain extent on towing cable length, and the ability of the following natural plum grape of this same model and the prediction followed is exactly effective so.Spread model after the calibration is realized turning to the ability of plum grape can be added on the nature plum grape to obtain desirable towing cable shape.

Power model in translation function

Can from the instruction of following list of references, derive desirable hydrodynamic force educational level model: " shape of marine streamer in the intersection current " of P.P.Krail and H.Brys, exploration gelphysicist association magazine, the 54th volume, the 3rd phase; " the towed flexible cylindrical dynamics " of Ann P Dowing, part 1: neutral floating element, part 2: negative floating element, fluid mechanics magazine, 187, the 507-532,533-571 page or leaf (1988); " the dynamic (dynamical) numerical simulation of underwater cable " of C.M.Ablow and S.Schechter, oceanographic engineering, 10:443-457 (1983).The used algorithm of behavior of prediction towing cable is based on these instructions in translation function, and has significantly improved the prediction to the towing cable behavior when combining with the spread control element model that is coupled in towing cable.The commercially available software that can realize the towing cable cable shape (the comprising SSD) example that is obtained by the power model theory of above-mentioned list of references is the OrcaFlex of Orcina company ^TMThe cable modeling software.

Trace is optimized formula

These formula are based on single spread body along the desirable and actual position of section operation route and/or the optimization carried out of shape, and suppose decoupling zero as previously described.One of outstanding constraint is the reaction time of various steering gears.Can depend on navigation speed (navigation solution rate) as a result with any frequency tolerance reaction time.Reaction time is the magnitude of burst period normally, promptly is generally tens seconds.Like this, turn to will plan sth. ahead several times blast and be to depend on ship and spread mostly of control.

Have again, in calibration calculations, will estimate the reaction time of spread control element based on the reaction time recent history of from aeronautical data input 112, learning.Then, the estimated value in each spread control element reaction time will be used to optimize the driving order (126) that trace estimation 124 is beneficial to calculate reality.

The track of ship

Can plan the path of ship so that the towpoint of towed spread control element remains in the constraint corridor, this corridor allows to carry out available turning in the spread, to realize target shape and trace.Like this, if give the desirable concrete shape that is realized by quilt towing spread control element surely, just can estimate the best trace of towpoint, it will provide the suitable cross stream component with respect to quilt towing spread the best trace.By the best trace of towing spread is to derive from the current generation target of operating.It may be that a passage of time is measured, and target may to be a certain offset bank occupy the identical trace that once occupied again in reference measurement.It may be closely to pass production platform, and its target is to make the hithermost distance of object (as the towing cable end) maintenance with platform 50m of being pulled.Utilize this trace realized, towed spread on such meaning by decoupling zero: promptly it can suitably motion in reference vessel system.

Allow to realize that the algorithm of this towpoint trace is as United States Patent (USP) 6,629, the 037 optimum cost ground drawing method of describing.Here specific spread element, for example towing cable offset bank or focus array center are endowed higher weights in the best trace inquiry of ship.Coupling model can be the straight line between ship towpoint and the high weight spread element for example, and accurate as the ability that the spread control system realizes this shape.The target that ship towpoint trace is estimated be provide towpoint and should key spread element between lateral drift.As long as available computing power allows, should be frequent as far as possible to recomputating of this trace.May not need to recomputate highly continually trace, because the towpoint of ship is in regional relative reference system, during once the typical case measured, being pulled the spread element was slowly with respect to the position horizontal change of ship towpoint.

Can be before programming phase utilizes the spread body to turn to the measurement of plum grape this trace of the incompatible calculating of spread object set of estimated value and measurement target estimate.The trace of this plan can be used in following algorithm, with the steering volume of considering in advance that once concrete measurement may need.

In case calculate trace, be starting point with this ship towpoint position, can calculate the plan that realizes this trace.Here the response time of ship is a limiting factor.The optimum cost trace that calculates must realize that it makes the degree minimum of oversteer with stationary mode.

Can go out to occupy the level and smooth shipping agency trace of best trace with following algorithm computation.The zone relative coordinate system is used for this development.In this reference frame, y is a longitudinal axis, and x is a lateral shaft.

Like this:

Δ Ves _x=X _Spi-X _Spi+n(formula 2)

Δ Ves _y=Y _Spi-Y _Spi+n(formula 3)

Wherein:

Spi is the i demolition point.

Spi+n is that the i demolition point adds the n time following blast.

Δ Ves _xBe current ship lateral coordinates and measured the poor of lateral coordinates after exploding through n time last time.

Δ Ves _yIt is the demolition point distance.

As shown in Figure 6, steering model is a straight line:

(Δ Ves _x) _{Turn to}=m (Δ Ves _y) _{Turn to}+ β (formula 4)

Wherein:

M is the ratio that the slope estimated maybe will turn to the horizontal change that causes and lengthwise movement.

β is current lateral coordinates.

Turn to plan to be based on the best-fit line of above-mentioned optimum cost trace estimated value.The observation equation of being write as with matrix expression is:

Ax=b+v (formula 5)

Wherein:

A = (\begin{matrix} 1 \\ 1 \\ 1 \\ 1 \end{matrix})

(formula 6)

X=m, the slope estimated value

B=(Δ Ves _x/ Δ Ves _y) _{Measured value}

V is that match is irregular

The least square solution of this equation can be write

X=(A ^tA) ^-1A ^tB (formula 7)

Above shown in simple A matrix bigger importance will be arranged in weighted solution.Shown in predict 4 demolition points for example forward, as 4 observation equations pointing out in the matrix A are represented.

In order to limit one or more caused steering volumes of demolition point that cause and can not point out trend that turn to by difference, we can introduce dynamic weighting.The least square solution writing of weighting:

X=(A ^tPA) ^-1A ^tPb (formula 8)

Wherein, at iteration (ii=1):

P = (\begin{matrix} Pii & 0 & 0 & 0 \\ 0 & Pii & 0 & 0 \\ 0 & 0 & Pii & 0 \\ 0 & 0 & 0 & Pii \end{matrix})

(formula 9)

(ii=1) can calculate residual error by iteration:

V _(ii=1)=Ax-b (formula 10)

The standard deviation of each single residual error and all residual errors compares.Maximum residul difference, it also causes the limit of excessive change working direction greater than meeting:

For example | v| _Ii＞2 σ _Ii, can be reduced weight, its weight is as the function of residual error, and then with

P _(ii+1)=f (if | v|) | v| _Ii＞2 σ _Ii(formula 11)

With

P _(ii+1)=P _IiIf | v| _Ii＜2 σ _Ii(formula 12)

Carry out match.

Continue weighting again, until till the variation of its working direction for the target of towing spread controlling object can be accepted.

The another kind of practice is that value n can increase, till secular trend provide acceptable working direction change.Depend on possible ship response, use a minimum value.If the working direction that causes changes greater than the limit, then can recomputate circuit based on best-fit to n+1, be lower than the limit until the working direction change.

According in the manual position time break, to the trace of each blast circulation double counting ship.In the application before measurement, the position of each blast is taken as the position that should reach along line navigation after reaching next explosion site.At each explosion time, the variation route of being followed is given the working direction that makes new advances.

At programming phase, research the best turns to strategy will allow to understand better by trial and error to what extent to expand the route fitting result forward before measurement.In addition, it will provide the approximate understanding that turns to that may run into about them to the navigator.It can be recomputated by online then, thereby provides needed turning at the scene, but has restriction and the difficulty period of identifying in the design phase measuring.

Determine that by some considerations maximum working direction changes, these considerations comprise:

1, the ability of ship 11 horizontal mobile spread element towpoints;

2, the ability (a spread control element will limit all the other elements) that laterally move on towed spread edge in once exploding;

What 3, when carrying out long prediction forward, be weighted based on there being blasts will exceed performance index (that is, will depart from best trace);

4, the value of measured zone, some zones in the overall measurement zone may be so important unlike other zones there, has buried target because believe other areas; And

5, spread element weights, the recomputating of optimum cost trace.

Normal ship section operating speed provides the suitable current relevant with device, to operate passive steering gear, as SFED.Must be not the working direction of ship not be caused appreciable impact by the power that change caused in the towed spread control element.As an example, consider to change rapidly from left cabin to right cabin significantly different tension force, it can cause the driftage of ship.Like this should towpoint monitor tension force with guarantee it can be not excessive and also with the ship balance.

Fig. 6 shows the best-fitting straight line that the forward prediction according to 4 demolition points obtains, and wherein recomputates the residual prediction value according to the position after each demolition point.The rapid degree that number decision turns to of exploding the future of definition route, a demolition point turns to the rapidest.

Fig. 7 shows the combination of best-fitting straight line as shown in Figure 6 in succession.Compare with previous measurement route, the forward-looking path of the segmentation that is caused is more level and smooth and more rational shipping agency track.It will be understood to those of skill in the art that above-described straight line path just can be for a kind of model that utilizes according to the present invention.

Focus

Can be used as the behavior that function that working direction changes is measured focus array.Focus array is mostly followed the trace of ship, but can because current and on less degree the influence owing to wind lateral drift takes place.Focus steering gear 17 can only drift about with the finite quantity compensate for lateral.In case surpass steering lock, turning to of ship is the only resource that focus is put into desired position.

Focus turn to calibration

The focus array behavior model that utilization was calibrated with respect to ship 11 can be along measuring route is predicted focus array with respect to ship position.The current and the wind along this route of prediction are the factors that can add forecast model.

The measured value that vertical and horizontal change is to be provided by the GPS receptacle on the focus array float.The location of the GPS receptacle on focus array provides the rate of change that rifle string array coordinate changes with respect to working direction.For each new ship working direction, making focus array 16 be stabilized in the used time of ship 11 back is the tolerance of system response with the track of taking.

Current are to the influence and the current calibration of focus array

Except the influence that the ship working direction changes, go back energy measurement owing to the influence of any other forces associated (as wind) to the focus behavior.The focus lateral drift that is caused by current can be represented and by simply relatively describing among Fig. 8 A and the 8B with the focus plum grape.The motion of ship provides the focus plum grape with the two result who causes of current vector in the reference frame relevant with the zone.Like this, if given R value (distance of towpoint arbitrfary point to the rifle string on the ship) and plum grape, just could predict the focus array coordinate.Because the relation of plum grape and current is known, do not having under the situation of significant beam wind, the plum grape of measuring provides water (flow) direction and can be used to calibrate any flow information of water source.

Fig. 8 B schematically shows current and ship's speed degree vector resolution.Air flow (wind) with cross stream component will make the focus array lateral drift to the effect of rifle array surface float, if the power that applies is enough big.In order to estimate transversal displacement, must use the aerodynamics model of float surf zone.

SFED

SFED can make reflection to the location estimation value of towing cable head reference point, as today these estimated values drive SSD plum grape mode in global controller.The degree of closeness of the seismic surveying coordinate of SFED or benchmark desired and preplanned according to the towpoint position of estimating will be to calculate SFED to drive the basis that (turning to) orders.The target of SFED is that the towing cable head is driven into the optimum position, to allow SSD best located towing cable length.In addition, SFED should make the towing cable front end stable, and this is vital for the SSD that is in the plum grape mode, because plum grape calculates from the front end reference point.

As the turning to of ship, drive the reaction time that order is based on SFED.During seismic surveying with the continuous coverage SFED reaction time and feed back to translation function to measure the eyes front period.---being fit to the straight line of the some demolition points in the place ahead---is how SFED calculates an example that drives order as preamble ship to be turned to described same model.

The orientation of a nominal for example perpendicular to the orientation that designs in advance, may be a desirable spread orientation during reference measurement.Playback contains the reference measurement orientation record of the each blast of reference measurement during duplicate measurements, to provide the SFED target orientation.Except orientation, can also realize located lateral by SFED.

Drag the reference measurement position of pulling front end will be used for determining which type of towing cable front end orientation will provide best repeatable position.The spread of seismic surveying repetition or passage of time has and reference measurement equal number or more towing cable.The spread of passage of time also has same or more close towing cable spacing.In all situations, its target can be the horizontal and vertical position coordinates coupling that makes the towing cable front end.

Fig. 9 demonstration sends to correction or the change of the driving order of SFED to the towing cable front end by execution.Correction causes towing cable front end and the angled skew of good route, thereby overcomes the angle of deviation θ that is caused by current.

Except orientation,, can also calculate an average transverse coordinate in the coordinate system related with ship for the purpose that turns to.This means that the towing cable front end can be used for as a target.Therefore, Figure 10 shows that towing cable front end center is fit to the desirable trace that turns to.

Can estimate of the behavior of spread front end with the similar fashion of above focus array being described with respect to the working direction of ship.Can measure the rotation of towpoint directly by to the location of the gps antenna on the towpoint or indirectly by the function of the variation in the towing cable front end changes in coordinates as the variation of ship working direction.As in the situation of focus array, will drive front end greater than the current of SFED steering capability and break away from balance.And SSD can consider the change of ship working direction in advance and estimate because the influence to the towing cable front end that the change of working direction causes is assisted SFED with this.

The tail buoy that can turn to

Because the towing cable after last SSD is uncontrolled, so tail buoy is useful for tail end is put in place.Location in the plum grape mode is the continuation of the straight line plumage line of being made by SSD, and this plumage line parallel is in the whole length of towing cable.For obtaining long skew, the tail buoy that can turn to is useful for making the towing cable tail end reach the target location.

Best plum grape is estimated

Make the decoupling zero of focus array trace and suppose that towing cable is a straight line, one group of coordinate fitting that previous receiver is occupied along towing cable is in alignment to be a solution that makes focus control and towing cable control decoupling zero.Ship cooperates with SFED so that towing cable front end (being called towing cable reference point (srp)) puts in place.In plan and the real-time both of these case, the coordinate predicted value of towing cable reference point (srp) will be by the starting point of global controller as towing cable before measurement.From the towing cable starting point of this prediction, can calculate the straight line least square fitting that reaches target along the reference measurement towing cable to each explosimeter.This match will provide the towing cable plum grape of optimum matching.

Can calculate the overall situation or single plum grape to each towing cable.Global controller will indicate SSD to adopt this plum grape to be used to turn to.Desired plum grape must be no faster than a limit specified from once exploding to the variation of blast next time.This can by isolating that (those) target that any order of quick change plum grape is responsible for, realize this restriction as in the ship track fitting a straight line.This calculating can be carried out before measurement, and limits the plum grape pace of change in calculating, and in other words, the blast of leaving body is reduced weight.

The best plum grape of whole towing cables

Can be according to the best plum grape of reference measurement coordinate Calculation.The drive amount that the best plum grape that realization is required by translation function changes remains the residual error that the difference with desirable receiver coordinate by reality constitutes.

For each blast, if the prediction coordinate of given towing cable reference point (srp), straight line is then arranged with srp (x, y) be starting point, and with respect to reference direction (as the section operator to) certain plum grape to distance R str who equals towing cable length of rear projection, this straight line in some sense (as least square) best-fit in a group of receivers coordinate that in passage of time is measured, will occupy.

Vertical axle is perpendicular to reference direction, and towing cable reference point (srp) is on this line.For convenience, transverse axis passes the reference point of ship, and the reference point of this ship is positioned at the middle part of ship and irrelevant with the working direction of ship, unless when ship is parallel to reference direction (for example section operator to) exactly.Initial point is at the intersection point of these two axis.Can make all towing cable reference point normalization to this system's initial point, provide the observation equation of common slope with formation.As shown in Figure 11 and 12, can estimate all reference measurement towing cables 18 " best-fit " line BF common slope and convert the common plum grape Ф of all towing cables of each blast to.Towing cable reference point (srp) will provide the y intercept of these straight lines.

Conversion from the slope to the plum grape is to polar conversion from rectangular coordinate.If any rectangular coordinate on best-fit line is to (x, y) (Rec (x, y)) has x/y=m, then

Arctan (m)=plum grape (formula 13)

(Reci (x, y)), if given forward travel distance with respect to a certain common origin, the horizontal value by the towing cable reference point cross stream component normalization of that towing cable then can form observation equation to produce slope for any receiver i on any towing cable j.

m _i=(x _i-b _j)/y _i(formula 14)

These observations can be provided the observation equation (being Ax=b+v) that shows suc as formula in 5 by formulism, and wherein the number of observation equation equals the receiver number on whole towing cables, i.e. n=(j*i).

A = (\begin{matrix} 1 \\ 1 \\ 1 \\ . . . \\ n \end{matrix}),

X=m (formula 15-16)

b = (\begin{matrix} (x_{1} - b_{1}) / y_{1} \\ (x_{2} - b_{1}) / y_{2} \\ (x_{3} - b_{1}) / y_{3} \\ . . . \\ (x_{i} - b_{1}) / y_{i} \\ (x_{1} - b_{1}) / y_{1} \\ (x_{2} - b_{2}) / y_{2} \\ . . . \\ (x_{i} - b_{2}) / y_{i} \\ . . . \\ (x_{1} - b_{j}) / y_{1} \\ (x_{2} - b_{j}) / y_{2} \\ . . . \\ (x_{i} - b_{j}) / y_{i} \end{matrix})

v = (\begin{matrix} x_{1} - {\hat{x}}_{1} \\ x_{2} - {\hat{x}}_{2} \\ x_{3} - {\hat{x}}_{3} \\ . . . \\ X_{n} - {\hat{x}}_{n} \end{matrix})

(formula 17-18)

Simply separating of equation 6 also is formula 8, and it is formula 9 that weighted least-squares is separated.

Equally,, can retrain slope by very big observed reading is reduced weight as in the formula 9, thereby the constraint plum grape.Have, be higher than the weight of those not too important offset bank by the weight that gives an offset bank, the slope estimated value can be constrained to and help the offset bank that has higher weights.

Using this estimated value is favourable for minimizing encryption on the straight line survey line of the design in advance that has current in nearly real-time condition lower edge, but perhaps the most usefully occupy the receiver position again for the blast of formerly measuring, the straight line survey line that once was difficult to follow design in advance in the previous measurement of carrying out there obtains needed covering.Here, towing cable reference point (srp) is followed the trace (that is, free measurement at interval) that helps providing best repeatable position, and the way of even now is more prone to but this estimation procedure becomes repetition receiver position current still not general.

The best plum grape of single towing cable

Figure 13 shows, above-mentioned all towing cables estimated that the method for best slope and plum grape can be applicable to estimate that the best slope of single towing cable 18 (sees towing cable S ₁And S ₂Best-fit line BF ₁And BF ₂).The benefit of optimizing each single towing cable slope with " best-fit " line is to provide the better match to reference measurement receiver coordinate.This benefit is brought complicacy to a certain degree, and promptly the plum grape from the towing cable to the towing cable can not be too big before the danger of collision takes place.Because in traditional spread, even those towing cables should not become not parallel dangerously yet under the situation that does not have steering gear to assist, this danger can frequently not take place in prediction is rational.

The plain mode of tackling this danger is to use the single towing cable plum grape of estimation to change to provide that those variations will cause relatively near degree and speed.If surpass the predefined limit, then need some weighted Criterion to coordinate these single plum grape.Owing to before running into real-time danger, can know the reference measurement coordinate, may reach the situation of avoiding danger limit so can before facing a danger, just dispose.In addition, real-time software test be used to estimate since single towing cable each other the plum grape of contradiction cause the danger of towing cable collision.

Current and wind

In this discussion, use term " natural plum grape " sign current and wind to make the effect of surface-object transverse movement.Under situation about laterally not turning to, because the change of ship working direction, focus array plum grape and tail buoy plum grape can take place for surperficial current and wind (also having wave).When in the estimated value of position, observing these phugoid modes of motion, just identify a trend.If this trend is short for the expanded range of spread spatially, then identifies a local trend and also can pay attention in advance by the spread control element thereafter.If this trend is lasting in time, then can spatially remembers and expect and when spread passes this transverse force zone, will take place once more by system.

Calibration

To the combinable all good estimated value of any independent measurement of ratio that provides that amount of the multiple measurement of an amount.This principle will be applied to spread control system described herein.Spread covers a big horizontal space and can be along its vertical stretching direction equipment measuring equipment, and this is to measure a chance controlling relevant amount with spread on most of the time and space.In addition, can estimate the error state of measurement mechanism according to the additional measurement of independently originating from other.

Current meter error source

With real time calibration to water velocity and contributive those measurements of direction.The current meter of installing on hull often provides the inaccurate measured value of current, and this depends on the position of current meter with respect to screw propeller disturbance or other interference.Have, what their were reported is the current of their place degree of depth again, and this current value may not be suitable for the surface or the towing cable degree of depth.

In least square fitting model calibration current

As mentioned before, can estimate to act on the direction of being pulled the current on the focus array by the response of marine equipment.The data that are positioned at the current counter device output of this marine equipment degree of depth can compare with power Model Calculation value, this power Model Calculation value is to find by the plum grape that calculates according to the coordinate estimated value, so the difference T of the current meter reading of observation and the current of calculating can be fit to an error model in the translation function.

The best model that is used for this relation will depend on the error characteristics of instrument and other source of errors of existence.Although it may be best that almost unlimited a plurality of mathematical functions are arranged, we use a simple linear model as an example.

This linear model has the constant component and the scale component that are similar to skew, and this scale component can be described with respect to the variation of (as current amplitude or marine device responds time) of a certain variable.The difference of calculating with the current of measuring is fit to this linear model.

Can combine to the measurement of the current that influence surface apparatus such as ship, focus array, SFED and tail buoy and to provide the optimum estimate of surperficial current.Except the current meter, the working direction of ship and focus array carry out also providing after wind and wave are proofreaied and correct the information about surperficial current in mechanical model.Do not turned to the transverse movement trend of explanation can be used as the tolerance of surperficial lateral current by the motion of ship or device yet.

In the towing cable degree of depth, provide an indication of there current along the flow measurement device of towing cable.Do not have in the auxiliary towing at straight line, when spread passes a current district, each current meter that is contained on the towing cable should provide the flow measurement result identical with the current meter of its front at any set point along its track, unless take place over time between path in succession.Moreover, function representation variation tendency of match (time dependent, the spatial dimension of supposing current is greater than in succession level that is installed in the device on the towing cable and vertical off setting) will demonstrate the skew of comparing with every other current meter that is caused by any one current meter.During less than the spread size, can estimate local current trend in the spatial dimension of current.

The transverse velocity calibration

Can estimate the transverse response of steering gear in real time.If given plum grape changes order, then reach the employed time of this target plum grape to disclose the used response time of driving order that single spread control element response takes place in real time environment.This information will feed back to the calculating of optimal drive order.

For example, the cross stream component of ship's speed degree can be fit to the function of this relation of description with the measured value of working direction variation.Mostly so complicated to the mathematical description that the little variation when passage of time is measured route and turned to of expection has been done, this is because the scope that this function relates to is little.The estimation of the order formula can be applied to go to obtain with the frequency that obtains the position renewal value updating value of steering gear response time.

The tension force calibration

Can measure at the vertical water speed relevant and calibrate tonometry with it.When by the tension force of hydrodynamic drag expection and those measured values when inconsistent, or a parameter in tension measurements or the hydrodinamical model is to cause the reason of prediction residual.Based on by the effective surface area of towed body, water speed and provided the desired value of tension force by parameters such as drag of towed vehicale coefficients.Proofread and correct these parameters with the hydrodinamical model that improves and the consistance of tensiometer will provide better tuning accurately.

Turn to sports school's standard

The navigation result helps to improve hydrodinamical model.Knowledge about SSD body orientation and water velocity provides the power that can be used for turning to.Can calculate this orientation according to the navigation result.Utilize this information, the SSD fin angle of attack can provide force vector more accurately, thereby improves the control to spread, as described in International Patent Application WO 00/20895.

Confirm

When estimating one group of best demolition point coordinates of targets and/or towing cable change of shape, carry out safety inspection to determine whether and between the spread element, to bump.If check determines that the optimal value that calculates is in more than the target danger limit, then onlinely report to the user.Then, the user obtains one group of other steering constraint and selects, and this will provide the Different Results of computation optimization.

When think can accept best demolition point target and/or towing cable change of shape after, they are used to the spread model and drive order to produce best spread control element.In the spread model, simulate these orders then to provide mode of operation.Also check these modes of operation at some limit, exceeding these limit may break down.If determine, just must surpass certain or some limit in these limit in order to realize desirable best demolition point target and/or towing cable change of shape, then will limit limit spread control element, and calculate another group and drive and order.The number of the optional value that can be used to test depends on getable computing velocity in the operation update cycle.Parallel therewith is, can calculate another and organize best demolition point coordinates of targets and/or towing cable change of shape, and they are to provide receivable one group to drive order and will require the less spread control element of making mistakes.If can not get the driving order of one group of safety, then on-line operation person carries out manual control by intelligent GUI under the guidance based on spread element operation status information and spread element motion history and the clear prediction that presents.

The relative degree of closeness check of spread control element

For all independent objects of control, have a few in the institute that can obtain this object position estimation value, will cause the different driving order of calculating greater than the location estimation difference of the defined limit.The limit of degree of closeness is based on the quality of location estimation.

The check of spread control element relative velocity

For having a few on the spread body of independent control, all velocity estimation relevant with point all must be less than a limit.This limit is based on the time that arrives check next time and the quality of velocity estimation value.If in the time of check next time, will bump or, then need to avoid the driving order of colliding near collision.This limit is the function of speed estimation error.

The check of spread control element barrier degree of closeness

The location estimation value of any point must be less than a certain limit with respect to the distance of all barriers in the spread.This limit is the function of position quality estimated value.

The check of spread control element barrier relative velocity

Next velocity estimation in the time period before the cycle velocity estimation value can not cause degree of closeness greater than this limit.This limit is the function of velocity estimation value quality.

The mechanical integrity check

The mechanical integrity check comprises: cable stretch is no more than limit; Steering gear wing angle does not reach halt etc.

Will be understood that from the description of preamble, in the preferred embodiments of the present invention or alternate embodiment, can carry out various modifications and change and do not depart from true spirit of the present invention.

This description should not explained this description in a limited sense just for the present invention is described.Scope of the present invention only should be determined by the language of attached claim.The meaning that term in the claims " comprises " is " comprising at least ", thus in the claims Yin Shu element to enumerate be the group of an opening." one " or other singular references are the plural forms that will comprise them, unless got rid of especially.

Claims

1. method comprises:

Pull a plurality of seismic surveying spread elements, these a plurality of seismic surveying spread elements are usually in the back of ship and have one or more spread control elements;

The coordinate position of one group of expectation of at least two in this spread control element is provided;

Measure the coordinate position of this at least two the one group of reality in this spread control element independently;

Difference between the coordinate position that calculates the expectation of this group and the coordinate position of this group reality is with the formation residual error; And

Use this residual error to calculate this at least two the driving order that is used for this spread control element as the set-point in one or more controllers.

2. method according to claim 1, wherein at least one in this controller used the pid correction method.

3. method according to claim 1 also comprises: the path of plan ship in the constraint corridor, this constraint corridor allows to carry out available turning in the spread control element, to realize the target shape and the trace of seismic surveying spread element.

4. method according to claim 1 also comprises: estimate the best trace of the towpoint of spread control element, this best trace provides the cross stream component with respect to the best trace of this spread control element.

5. method according to claim 1, wherein the coordinate position of this group expectation provides by being selected from one or more following data types: from the mode of operation of this spread control element sensor associated, the environmental data that is used to measure and measure design data.

6. method according to claim 1, wherein each in this driving order is used to control at least one in position, speed and the working direction of ship.

7. method according to claim 1, wherein this driving order comprises at least one order of the rudder angle of revolution speed of propeller, ship of airscrew pitch, the ship of thruster setting, the ship of thruster, the ship of the screw propeller that is used for controlling ship, ship or its combination.

8. method according to claim 1, wherein this spread control element comprises ship control element, focus control element and the towing cable control element that is fitted to each other.

9. method according to claim 1, wherein this spread control element comprises ship control element and the focus control element that is fitted to each other.

10. method according to claim 1, wherein this spread control element comprises ship control element and the towing cable control element that is fitted to each other.

11. method according to claim 1, wherein this spread control element comprises focus control element and the towing cable control element that is fitted to each other.

12. method according to claim 1, wherein this spread control element comprises at least two ship control elements that are fitted to each other.

13. method according to claim 12, wherein in these at least two ship control elements is associated with first ship, and in these at least two ship control elements another is associated with second ship.

14. method according to claim 1 is wherein used the spread model that the coordinate position of this group expectation is provided, and is comprised:

Use these remnants to estimate one or more parameters of this spread model; And

This parameter is fed back in this spread model.

15. a method comprises:

Pull a plurality of seismic surveying focus and receiver, they are usually in the ship back and have one or more spread control elements;

Estimate the position of focus; And

Only be enabled near the selected portion of the focus the lateral attitude of expectation.

16. method according to claim 15, wherein the quantity of this selected portion of this focus is less than the total quantity of focus.

17. method according to claim 15 is wherein pulled receiver in many straight line towing cables; And wherein this selected portion of this focus forms at least one straight line focus array parallel with this towing cable.

18. method according to claim 15 also comprises:

Collect the input data from seismic surveying spread with a plurality of spread control elements, a plurality of navigation node and a plurality of focus and receiver;

Use one or more aeronautical datas, one or more mode of operation and one or more environmental data to estimate the position of focus and receiver;

The part using estimated position and comprise the input data of measuring design data is at least determined the best trace of focus and receiver; And

The driving order of at least one that use determined best trace to calculate at least to be used for the spread control element.

19. method according to claim 15, wherein this in this spread control element at least one be ship or the spread control element that is used for receiver.

20. a seismic surveying device comprises:

Ship;

A plurality of seismic surveying focus and receiver, its usually by towing in the back of this ship and have one or more spread control elements;

Controller, it is coupled to this seismic surveying focus, receiver and spread control element, and wherein this controller is estimated the position of focus and is enabled near the lateral attitude of expectation focus selectively.

21. a method comprises:

Coordination is selected from the location of at least two following elements: ship control element, focus control element and towing cable control element; And

Send positioning command to the element of being coordinated.

22. method according to claim 21, the localization step of wherein coordinating at least two elements comprises:

The coordinate position of one group of these at least two elements expectation is provided, and the coordinate position of wherein should group expecting provides by being selected from one or more following data types: from the mode of operation of these at least two element sensor associated, the environmental data that is used to measure and measurement design data;

Measure the coordinate position of one group of reality of these at least two elements independently;

Use this residual error to calculate the driving order that is used for these at least two elements as the set-point in one or more controllers.

23. method according to claim 21, wherein these at least two elements comprise one or more focus control elements and the one or more ship control element that is fitted to each other.

24. method according to claim 21, wherein these at least two elements comprise one or more towing cable control elements and the one or more ship control element that is fitted to each other.

25. method according to claim 21, wherein these at least two elements comprise one or more towing cable control elements and the one or more focus control element that is fitted to each other.

26. method according to claim 21, wherein these at least two elements comprise the one or more ship control elements that are fitted to each other, one or more focus control element and one or more towing cable control element.

27. a method comprises:

Seismic surveying spread with one or many ships and one or more spread control elements is provided, and wherein this spread control element comprises at least two ship control elements; And

Control this seismic surveying spread by the location of coordinating these at least two ship control elements.

28. method according to claim 26, wherein in this ship control element is associated with first ship, and in this ship control element another is associated with second ship.