SU894640A1 - Digital system for measuring depth position of marine piezoseismographic log - Google Patents

Description

parts on digital components and units This system contains in the towed part a pressure transducer into an electrical signal, the transmission line of the latter, and in the on-board part, the readout and time driver units, of which the first is connected to the transmission line and contains in series the connection of the receiving counter equipped with a reset pulse shaper , the accumulator and the recorder, and the second is the sequence of the connection of the reference frequency generator, the timing counter and the focusing device, for a pulse duration of 3,

However, the known system also has insufficient stability and accuracy due to the two-stage design of the transducers, whose short circuits, the first step of converting pressure to voltage, is located in the towed part, and the second step of converting voltage to frequency, in the side part. As a result, the system also has inherent errors and primary transformation instability.

The purpose of the invention is to improve the accuracy and stability of the system by calculating differential-differential transducers with direct conversion of pressure into a mechanical parameter (the resonant frequency of the self-oscillating link) and introducing into the system three correctors the entire set of static characteristics of the transducers (of which one mechanical equalizer is in each converter , and two electric ones - in the side part) and a common variator of the system resolution (in the side part).

The goal is achieved by introducing a synchronization line into the towed part of the system, divided together with the transmission line into segments, and each converter consists of a differential mechanical correction of the conversion slope with strong-sensitive quartz resonators fixed in it, connected to two self-oscillating circuits connected through a subtractor frequency with a signal input of the time selector, the pulse output of the latter is connected via a disjunctor to the neighboring segments of the first and the potential output - by the time setting, the single-oscillator input, the starting segments 1 to the input and output of which are connected to the adjacent segments of the synchronization line and the control inputs of the time selector, and the system resolution variator in the onboard part of the system is included in the switch of the older bits of the timing counter , electrical correctors of initial softening and toughness; each converter, both made in the form of a code-matrix device with a dialed field, a counter and a decoded number of channels, the outputs of which are connected to code inputs of the encoder and the outputs of the latter to the installation inputs of the receiving and timing links, and the synchronization line is connected to the gate input of the encoder, input the counter of the number of channels and the output of the duration generator, which has an additional time specifying the input connected to the initial output of the decoder.

Each mechanical steepness corrector is made in the form of a hollow cylinder with one of the bases in the form of a membrane, between the rigid center of which and the bottom of the cylinder is the forming surface of an elastic ring having two diametrically opposite diameters of the plane of the cross section and 90 ° of the protrusion the area of the surface of the quartz resonator, and the angle of rotation of the ring in each equalizer is set by the equality of the slope in all converters.

Each frequency subtractor is made in the form of three triggers and an inverter, the counting inputs of two triggers are connected to the output of a self-oscillating circuit of a lower frequency, and the inputs of the zero state setting directly and through the inverter are connected to the output circuit of a higher frequency, and the outputs are connected to the installation inputs of the third trigger , performed on two two-input logic inverters with cross-coupling.

Each time selector is designed as a trigger, to the installation inputs of which the threshold time discriminator and differentiator are connected, and to you - the serial connection of the conjunctor and the disjunctor, and the inputs of the discriminator and differentiator serve as control inputs of the temporary selector, its potential output serves as the trigger output , the signal input is the second input of the conjunctor, and the pulse output is the output of the disjunctor, the second input of which is combined with the input of the differentiator.

Each self-oscillating circuit is made in the form of a positive feedback loop, including a pulse amplifier and resonator plates.

Besides. The reset pulse shapers and pulse durations are made similar to the corresponding time selector discriminator and one-shot located in the converters of the towed part of the system, and the drive is made in the form of shift registers with group transfer circuits

FIG. 1 shows an enlarged functional diagram of the system; in fig. 2 - functional diagram of the subtractor frequency and the time selector; in fig. 3 - time diagrams of the temporary selector; in fig. 4 - timing diagrams of the subtractor frequency.

The system (Fig. 1) consists of a towed 1 and an onboard 2 parts. The towed part contains 3 pressure-to-frequency transducers, structurally designed as a sealed cylindrical insert inside the cavity of a marine piezoseismographic spit hose, a transmission line of frequency signals on board, divided into segments 4, and the synchronization line from the board, also divided into segments 5. The number of segments corresponds to the number of transducers and is a multiple of the number of piezoseismographic spit sections. Each transducer has a differential mechanical correction of the steepness of the transform with two power sensors 1 and quartz resonators 7 and 8 fixed in it, two self-oscillating circuits 9 and 10, a frequency subtraction circuit 11, a time selector 12, a single-shot 13 with starting 14 and time setting 15 inputs, as well as a two-way disjunctor 16. The corrector 6 is made in the form of a hollow cylinder 17 with one of the bases in the form of a membrane 18, between the rigid center 19 of which and the bottom of the cylinder lies outside the elastic surface of the meta It has two diametrically opposed, at a mutual angle of 90, pairs of lugs 21 attached to it (shown by a dotted line in the peripheral area of the surface of quartz resonators 7 and 8. The angular position of the ring 20 in each converter with respect to the support points corresponds to equality of slope in all converters, taking into account the required initial, outputting the output frequency from the subtraction circuit 11 beyond the frequency band of the received seismic signals.

Each self-oscillating circuit 9 and 10 is formed by a pulse amplifier, for example, in the form of two stages 22, between which a capacitor 23 and the plates of a crystal resonator 7 or 8 are connected. The outputs of the corresponding stages 22 in the circuits are connected to the inputs 24 and 25 of the frequency subtraction circuit 11, and its output connected to the signal input 26 of the time selector 12, which in addition to it has two more control inputs 27 and 2B, as well as two outputs (pulse 29 and potential 30), 5 the first of which is connected to the input of the disjunctor 16 and the second to the master time entrance 15 univibrator 13. In this case neighboring segments 5 are connected to the clock line in each

0 converter with triggering input 14 and output of one-shot 13, and adjacent segments 4 transmission lines are connected in each converter with another input and output of disjunctor 16. Control inputs 27 and 28 of the time selector are connected in parallel to adjacent segments 5 of the synchronization line.

The on-board part of the system system contains a block time in the form of a generator of 31 reference frequency pulses, a timing counter 32, equipped with a system variator of resolution of the system in the form of a Co Futator 33 high-order bits 34 of this counter, a receiver counter 35, as well as a readout block, containing the drive 36 and the device 37 registration i the Clock counter its output connected to the trigger input 38

0 shaper pulse duration performed on the one-shot 39, similar to the one-shot 13 and having time zadosyas input 40. Receiving counter 35 is connected to the line

 transmission, to which through the circuit 41 of the reset pulse is connected to its circuit 42 reset. The inputs 43 and 44 for setting the initial state of the counters 32 and 35 are respectively connected to the code outputs of the electrical equalizer 45 of the slope of each transducer and the equalizer 46 of its initial offset. Each corrector is designed as a code-matrix encoder with a type-setting field (conditionally

5 are labeled 47 and 4B), the code inputs 49 of which are connected to the outputs of the counter 50 of the number of channels via the decoder 51. At the same time, the gating impulse inputs 52 of the encoder are connected to the output of the one-vibrator 39, the time specifying the input 40 of which is connected to the initial (corresponding to the first channel) output 53 decoder 51.

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For synchronous transmission of measurements for each depth channel to the registration device 37, the group transfer chain of the shift accumulator 36 is connected to the output

0 one-shot 39. The depth of the streamer is monitored on all channels by the end multiplex frame signal of the time multiplex, which is performed by connecting the initial output 53 of the decoder 51 to the gate input 54 of the recorder 37. In this case, each frequency deactivation circuit 11 contains three flip-flops, of which two (55 and 56) have counting inputs 57 and 58 and inputs 59 and 60 of the zero state setup, and the third is implemented on two logical inverters 61 and 62 with cross-coupling. The signal inputs 63 and 64 of the third trigger are connected to the inverted outputs of the flip-flops 55 and 56, the counting inputs of which are combined and connected to the output of the auto-oscillating circuit of the smaller of the compared frequencies, inputs 59 and 60 of the zero state are connected to the output of the circuit of the larger of the frequencies directly and by the inverter 65. Each time selector 12 is made in the form of a trigger 66, a threshold temporal minator 68 is connected to the single-state setting input 67, and a differential differential is connected to the zero-setting input 69. An inverter 70 with signal inversion, as well as a two-input conjugator 71, inputs 72 and 73 of which are connected to the output of a subtractor of frequency 11 and to the output of a trigger 66. At the same time, the inputs of the discriminator and differentiator serve as control inputs 27 and 28 of the selector, its output 30 serves as the trigger output 66, the signal input 26 is the input of conjuncer 71, and the pulse output 29 is the output of the additional disjunctor 74, whose inputs are connected to the output of conjunctor 71 and the output of differentiator 70. The system works in a similar way. In converters 3 of the towed part 1 of the system, the pressure of the fluid inside the hose is converted by means of the membrane 1B into the force F, under the action of which the frequency of the quartz resonators 7 and 8 is tuned. The self-oscillating circuits 9 and 10, built on a positive-loop ring circuit, generate pulsed sequences with a frequency equal to fb plus or minus the frequency deviation of Af under the force of f. In this case, the plus sign corresponds to the tensile force, and the minus sign corresponds to the compressive force. The deviation is proportional to F, with no higher-order effects, where Kj is 30.8 -10 cm-N is the coefficient of force sensitivity, depending on the cut-off angle of the quartz plate and the relative direction of application of force; D is the diameter of the resonator disks 7 and 8; 1 - 0.8 ... - reducing factor associated with the design of the crystal holder and the type of its deformation under the action of force F. Due to the arrangement of pairs of fastening lugs 21 on the ring (crystal holder) 20 at a mutual angle of 90, force F is transmitted from the membrane to the resonators 7 and 8 are differential: the resonator 8 experiences a compressive force, while the resonator 7 experiences a compressive force. The pulse sequences from the outputs of the stages 22 in self-oscillating circuits 9 (Fig.4.2) and 10 (Fig.4.1) are received respectively at the inputs 24 and 25 of the digital frequency reader, where the exclusion of the initial level, frequency f and the selection of doubled frequency deviation 2Af occur. The subtractor works as follows. When applied to the counting inputs 57 and 59, the trigger points 55 and 56 are of a pulse sequence of lower frequency from input 25 (Fig. 4.1), and their inputs for setting the zero state 60 and 59 are of a pulse sequence of higher frequency from another input 24 directly and through inverter 65 (Fig. 4.2 and 4.4), at the inputs fi3 and 64 of the valves 61 and 62, two mutually shifted sequences of pulses of variable duration are formed (Fig.4.3 and 4.5). Thank you to the parallel-cross-connection of the outputs and the second inputs of these gates, one of them (61) is formed and pulse sequence (fig.4.6) with the difference frequency 2uf. the output signal of the subtractor 11. This signal is transmitted to the input 72 of the time selector 12, which is controlled by signals from the side 2 of the system. A synchronization and pulse sequence arrives on the synchronization line 5 to the converter 3, which determines the duration and frequency of connection of the frequency-pulse output of the converter to the data line. A symptom of the operation of the time selector 12, which commutes the output of the frequency subtraction circuit, is the presence of marker clock pulses in the sequence that differ from others with a longer duration (Fig. 3.1). When a marker arrives at the input 27 of the time selector on its trailing edge, the time discriminator 68 (Fig. 2) is triggered, which does not respond to sync pulses with a shorter duration, and sets trigger 66 to a single state.

The logical 1 signal at the output of the trigger 66 permits the output signal of the frequency subtraction circuit to pass through the input 72 of the conjunctor 71 and then through disjunctors 74 and 16 to the 4th transmission line. With the arrival of the next short sync pulse, the one-shot 13 with logic 1 for the time as driver input 15 forms a marker that is transmitted along the synchronization line to the next converter 15. The same marker goes to the Input 28 of the time selector of this converter. Through disjunctions 74 and 16, it passes to the transmission line, thus dividing the temporary channels for transmitting signals from different transducers. The falling edge of the same marker, allocated by the inverting differentiator 7O, is set to the zero state by trigger 66 (Fig. 3.2). As a result, the frequency output 26 of the frequency subtraction circuit is disconnected from the transmission line by the conjunctor 71. At the same time, at the input 15 of the single-oscillator 13c, the trigger 66 establishes a logical O. Short-circuit pulses arrive at the next input 14 of the new sync pulses to the next section of the synchronization line. (Fig.3.3). After the end of the sequential demand of all converters, the marker goes to the synchronization line from the main system unit. A new measurement cycle begins. The polling time of each converter is determined by the time interval between the corresponding sync pulses from the onboard part of the system, the first converter corresponds to the marker, and the second — the next a short sync pulse, the third a second short sync pulse, etc. Synchronization intervals for jajlautc timed counter 32, made in the form of a subtractive counter. The subtraction of the counter content is effected by pulses of a stable frequency of the oscillator 31. The counter zero signal triggers the one-shot 39, which directly generates the sync pulses for the synchronization line. The duration of the clock pulses depends on the state of the channel counter 50, which counts the number of clock pulses. For the first channel, the one-shot input 40 from the first output of the counter-counter decoder 51 is given a logical 1 signal, and a marker is formed at the single-vibrator output, and a logical O signal is generated for all residuals at input 40, and a single sync pulse. The switch i33, which switches the higher bits of the clock counter, makes it possible to change the resolution of the measurement system as a whole (for example, to degrade it in order to reduce the polling time). The electrical offset of the slope 45 is intended for the secondary compensation of errors in the installation of the slope of each converter by mechanical correctors. With the release of its code-matrix encoder to the installation inputs of timed

o the counter receives the measurement interval code set on the dial field 47. The outputs of the decoder 51 switch to the installation inputs of the timing counter 32 the ins measurement code for the converter corresponding to the state of the 50 channel counter. The entry of the code in the counter 32 occurs on the clock pulse per pulse. 52 input code-matrix encoder.

On line 4 gears in the side of the system are fed; frequency-pulse signals of individual channels, separated by marks. The conversion into the readout code of the unitary code, determined by the number of frequency pulses proportional to the measured depth, during the measurement interval, takes place in the receiving summing counter 35. Before the beginning of the data of any of the channels, the return code of the corresponding transducer is entered into the counter.

5 is mounted on the dial pad 48 of the initial offset offset 46. The synchronization is performed by a counter decoder of 50 channels and sync pulses, similar to that considered

0, the slope correction in the timing counter 32. As a result of the sum of the pulse-frequency sequence with the return code in the receiving counter, the initial offset of the converter is subtracted from its current heading.

The marker arriving at the end of the measurement interval of this channel by the circuit 41. Its output signal transfers from the receiving counter 35 to the shift registers of accumulator 36 the generated reading depth code and prepares the counter to receive the next channel. The shift registers form a buffer of 5 memory for one measurement cycle and are controlled by clock pulses. At the end of the survey of all the transducers, the accumulated data on the depth of the signal from the first output of the decoder 51 of the kaishov counter arrive at the device in registration for visual inspection and recording.

The beneficial effect in the system is achieved in this way.

The force-sensitive quartz resonators have a specific feature associated with the technological variation of the coefficient values depending on the random relative displacement of the points of attachment of the peripheral area to the protrusions of the ring, the magnitude of the actual fastening area along the protrusions of the deformation character (stretching or contractive), etc. This causes errors such as the initial frequency shift at the output of subtractor 11 and the difference in transform steepness of individual transducers. For initial alignment of steepness is performed when assembling transducers 3 by introducing a differential mechanical equalizer in the form of a rotary ring inside the hollow cylinder between its membrane crest and bottom. In this case, the angular position of the ring, which is at the same time the crystal carrier, is set equal to the slope of all the transducers. In addition, a similar design with a pair of resonators and an reader reduces the sensitivity of the transducers to general destabilizing factors (supply voltage, temperature, mechanical stress, etc.).

By means of an electrical equalizer, the initial offset value is compensated for the total initial value of the output frequency that occurs after equalizing the steepness, and the indication of the initial pressure of the oil fluid inside the hose sections of the marine piezo-seismograph spit. This correction is performed by means of a keypad before starting work.

By means of the electrical corrector of the steepness, an individual correction of the nonidentity of the steepness of the individual channels is made, independent of the adjustment of the angles of the mechanical correctors. This is necessary when increasing the resolution of the system capacity by means of the corresponding variator, when in order to increase the time intervals of the compaction, inaccuracies in the installation of mechanical correctors are felt, more than plus or minus one unit of the lower digit of the receiving counter.

Claims (7)

1. A digital system for measuring the depth position of a marine piezo-seismographic spit, containing in the towed part a pressure transducer into an electrical signal and the transmission line of the latter, and in the onboard part — a counting and preset time blocks, of which the first connected to the transmission and contains a serially connected receiving counter, supplied (with a reset impulse shaper, a drive and a recording device, and the second with a serially connected reference frequency generator, a timing counter and Lorg1irator for pulse duration, which is designed to improve stability and accuracy measurement, a synchronization line is inserted into the towed part of the system, which is divided together with the transmission line into segments, and each converter consists of a differential mechanical of the steepness corrector with resonators fixed in non-sensitive quartz-like resonators, are included in two self-oscillating circuits connected via a frequency subtractor to the signal input of the time selector, the pulse output of the latter connected via a disjunctor to the adjacent segments of the transmission line, and the potential output by the time of the single input , to the triggering input and output of which the adjacent segments of the synchronization line and the control of the time selector inputs are connected, and in the onboard part of the system You have entered a system resolution variator in the form of a switch of higher-order clock counter, electrical offsets for the initial offset and slope of each converter, both implemented in a code-matrix jffrator with a set field, a number of channels, and a decoder for the number of channels whose outputs are connected to code inputs encoders, and the outputs of the latter to the installation inputs of the receiving and timing counters, with the synchronization line connected to the gating input of each 1-1 digitizer, the input of the number counter anal and the output of the additional time duration imekichego defining an input coupled to the primary output of the decoder. 2. The digital system according to claim 1, wherein the mechanical offset of the steepness is made in the form of a hollow cylinder with one of the bases in the form of a membrane, between the hard center of which and the bottom of the cylinder is the surface of an elastic ring, which has two on each section plane The diametrically opposed, at a mutual angle of 90, are a pair of protrusions to which the surface of the quartz resonator is attached to the peripheral region, and the angle of rotation of the ring in each equalizer is set to equal steepness in all transforms L x. 3. The digital system according to claim 1, which makes it possible that the frequency subtractor is made in the form of three triggers and an inverter, the counting inputs of the two triggers are connected with the output of a self-oscillating circuit of a lower frequency, and the inputs of the zero-state setup directly and through the inverter with the output of a circuit of a higher frequency, and the outputs are connected to the installation inputs of a third trigger, performed on two two-input logic cross-talk inverters. 4. The digital system according to claim 1, which differs from the fact that the time selector is designed as a trigger, to the installation inputs of which the threshold time discriminator and differentiator are connected, and the output connection of the conjunctor Diz1rn1 then {) a, and the inputs the discriminator and the differentiator serve as control inputs of the time selector, its potential output is the trigger output, the signal input is the second input of the conjunctor, and the pulse output is the output disjunctor, the second input of which is combined with the input of the differentiator. 5. Tsifrova system according to P.-1, which is characterized by the fact that each self-oscillating circuit is made in the form of a positive feedback loop including a pulse amplifier and resonator plates. 6.Digital system 1a on PP. 1 and 4, characterized in that the reset pulse formers and 0 pulse durations are made similar to the selector time discriminator and single-oscillator, respectively, located in the transducers of the towed part of the system. five 7. A digital system according to claim 1, which is characterized by the fact that the drive is made in the form of shift registers with chains of group transfer of bits. 0 Sources of information taken into account in the examination 1. US Patent No. 3259399, cl. 340-7, published. 1967. 2. US patent 3439319, cl. 340-7, published. 1969. five 3 US patent number 3837224, CL. 73-170A, published. 1975 (prototype). "Nh --SilS 1 I