阅读说明：本技术 一种随钻声波异步串口信号同步的方法 (Method for synchronizing acoustic wave asynchronous serial port signals while drilling ) 是由 魏富强 孙云涛 陈文轩 张文秀 郑健 于 2019-09-12 设计创作，主要内容包括：本发明涉及随钻测井技术领域,提供了一种随钻声波异步串口信号同步的方法,使用异步串口通讯方式实现发射端与接收主控板之间的通讯与高压信号隔离；接收控制板作为主控端通过异步串口通讯方式为发射端配置参数,并控制声源的激发；发射端为同步声源激发信号发起者；通过两者的配合在异步通讯条件下实现信号同步；发射端包括若干发射板,发射板与接收控制板的异步串口通讯通过2根数据线R+和R-实现。本发明的有益效果：发射端强电高压信号不影响接收端数据采集与控制；发射端与接收端只需2根信号线即可完成数据传输与信号同步,不需额外加信号线作为同步信号；同步精度高,最大误差控制在一个晶振时钟之内；方法简单高效,适于推广应用。(The invention relates to the technical field of logging while drilling, and provides a method for synchronizing sound wave asynchronous serial port signals while drilling, which realizes communication and high-voltage signal isolation between a transmitting end and a receiving main control board by using an asynchronous serial port communication mode; the receiving control board is used as a main control end to configure parameters for the transmitting end in an asynchronous serial port communication mode and control the excitation of a sound source; the transmitting terminal is a synchronous sound source excitation signal initiator; the signal synchronization is realized under the condition of asynchronous communication through the cooperation of the two; the transmitting end comprises a plurality of transmitting plates, and asynchronous serial port communication between the transmitting plates and the receiving control plate is realized through 2 data lines R + and R-. The invention has the beneficial effects that: the strong electric high voltage signal of the transmitting terminal does not influence the data acquisition and control of the receiving terminal; the transmitting end and the receiving end can complete data transmission and signal synchronization only by 2 signal lines without additionally adding signal lines as synchronization signals; the synchronization precision is high, and the maximum error is controlled within one crystal oscillator clock; the method is simple and efficient, and is suitable for popularization and application.)

1. A method for synchronizing sound wave asynchronous serial port signals while drilling is characterized in that communication and high-voltage signal isolation between a transmitting end and a receiving main control board are achieved by using an asynchronous serial port communication mode; the receiving control board is used as a main control end to configure parameters for the transmitting end in an asynchronous serial port communication mode and control excitation of a sound source; the transmitting terminal is an initiator of a synchronous sound source excitation signal; and the precise synchronization of signals is realized under the condition of asynchronous communication through the matching between the transmitting terminal and the receiving main control board.

2. The method for synchronizing while-drilling acoustic wave asynchronous serial port signals as recited in claim 1, wherein the transmitting end comprises a plurality of transmitting boards, and the asynchronous serial port communication between the transmitting boards and the receiving control board is realized through 2 data lines R + and R-.

3. The method for synchronizing while-drilling acoustic wave asynchronous serial port signals as recited in claim 2, the method specifically comprising:

s1, configuring parameters for a plurality of transmitting boards by a Micro Control Unit (MCU) of the receiving main control board through a driving chip, and sequentially returning a command of successful receiving to the receiving main control board after the plurality of transmitting boards receive the configuration parameters;

s2, the MCU of the receiving main control board sends a command for exciting a sound source to the plurality of emission boards in a broadcast mode through a driving chip, meanwhile, the configuration of the R + pin corresponding to the MCU of the receiving main control board is changed from a serial port communication mode to a general input port mode, the rising edge interrupt function of the R + pin is started, and the first rising edge of the R + pin caused by the return command of the emission end is ready to be captured;

s3, after the transmitting plates successfully receive the command of exciting the sound source, the plurality of transmitting plates start to capture the first rising edge of R +;

s4, the first transmitting board returns a command which is successfully received to the receiving main control board after the interruption of the first rising edge of R + is started by utilizing the parallel processing performance of the FPGA, and the rest transmitting boards do not return the command;

s5, placesAfter the first rising edge is captured by the emitting plates, the capturing of the rising edge of the R + signal line is closed, meanwhile, the timer is started to time, and T is passed₁After time, monopole emission or 4-pole emission is realized according to received configuration parameters, different emission modes are realized, and signal synchronization among a plurality of emission plates at an emission end is ensured;

s6, after the MCU of the receiving main control board captures the first rising edge of R +, reconfiguring the pin corresponding to R + into a serial port communication mode to prepare for next communication; starting a timer at the time of T₂After the time, sending a command for starting to collect the sound wave signal to the data collection circuit in a rising edge interruption mode;

s7, the data acquisition circuit acquires data with a specific length at a sampling rate of a certain frequency; the delta T ═ T of the data acquisition circuit after the sound source emits a sound wave signal₂-T₁The time begins to collect data.

4. The method for synchronizing while drilling acoustic wave asynchronous serial port signals as recited in claim 3, wherein the number of the transmitting plates is 4.

5. The method for synchronizing while drilling acoustic wave asynchronous serial port signals as recited in claim 3, wherein in step S1, the parameters comprise operating mode, dead time, excitation frequency and waiting time; the driving chip is an RS485 chip.

6. The method for synchronizing while drilling acoustic wave asynchronous serial port signals as recited in claim 3, wherein in step S2, the capture frequency for the rising edge capture is set to be at most 100 MHz.

7. The method for synchronizing while drilling acoustic wave asynchronous serial port signals as recited in claim 3, wherein in step S3, the capture frequency of the first rising edge of the pair of R + by the transmitting plate is 25 MHz.

8. The method for synchronizing while-drilling acoustic wave asynchronous serial port signals as recited in claim 3, wherein in step S3, the capture frequency of the first rising edge of the pair R + by the transmitting plate is the highest clock frequency of the field programmable gate array FPGA.

9. The method for synchronizing while-drilling acoustic wave asynchronous serial port signals as recited in claim 3, wherein in step S5, the precision of the timer is the clock precision of the crystal oscillator.

10. The method for synchronizing while-drilling acoustic wave asynchronous serial port signals as claimed in any one of claims 1 to 9, wherein the signal synchronization precision is consistent with the crystal oscillator frequency, the maximum error is controlled within one crystal oscillator clock, and the precision requirement of acoustic logging is met.

Technical Field

The invention relates to the technical field of logging while drilling, in particular to a method for synchronizing sound wave asynchronous serial port signals while drilling.

Background

The acoustic logging while drilling is different from a cable acoustic logging instrument, and in the acoustic logging while drilling, the control and data processing are quickly completed underground due to the limitation of the transmission rate. The transmitting and receiving time sequence control of the acoustic logging-while-drilling instrument is complex, the data calculation amount is large, and in order to ensure the real-time performance, the control and data processing processes need to be reasonably scheduled to coordinate the whole work of the instrument.

The electronic system of the acoustic logging-while-drilling instrument consists of an acoustic wave transmitting circuit, a signal receiving and processing circuit, a data acquisition circuit, a receiving main control circuit, a power supply circuit and the like. The transmitting circuit receives the excitation signal and then excites the sound source to generate a sound wave signal with certain frequency and waveform.

The current sound source mode of the latest generation is a quadrupole sound source, and the synchronization performance of the driving signals of the sound sources and the driving waveforms directly influence the quality of the signals received by the data acquisition circuit. The control and data processing circuit ensures that the time interval between the transmitting circuit and the signal receiving circuit is kept accurate and stable, so that the sound wave signal transmitted by the transmitting end can be correctly received.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for synchronizing sound wave asynchronous serial port signals while drilling, which can realize signal isolation between a transmitting end and a receiving end and ensure accurate synchronization.

The technical scheme adopted by the invention is as follows:

a method for synchronizing acoustic wave asynchronous serial port signals while drilling is characterized in that communication and high-voltage signal isolation between a transmitting end and a receiving main control board are realized by using an asynchronous serial port communication mode; the receiving control board is used as a main control end to configure parameters for the transmitting end in an asynchronous serial port communication mode and control excitation of a sound source; the transmitting terminal is an initiator of a synchronous sound source excitation signal; and the synchronization of signals is realized under the condition of asynchronous communication through the matching between the transmitting end and the receiving main control board.

Furthermore, the transmitting end comprises a plurality of transmitting boards, the asynchronous serial port communication between the transmitting boards and the receiving control board is realized through 2 data lines R + and R-, and the receiving main control board and the transmitting boards are directly hung on the two data lines (equivalent to a bus).

Further, the method specifically comprises the following steps:

s1, configuring parameters for a plurality of transmitting boards by a micro control unit of the receiving main control board through a driving chip, and sequentially returning a command of 'successful receiving' to the receiving main control board after the transmitting boards receive the configuration parameters;

s2, the micro control unit of the receiving main control board sends a command for exciting a sound source to the plurality of transmitting boards in a broadcasting mode through the driving chip, meanwhile, the configuration of the R + pin corresponding to the micro control unit of the receiving main control board is changed from a serial port communication mode to a general input port mode, the rising edge interrupt function of the corresponding pin is started, and the first rising edge of the corresponding pin caused when the transmitting end returns the command is ready to be captured;

s3, after the transmitting plates successfully receive the command of exciting the sound source, the plurality of transmitting plates start to capture the first rising edge of R +;

s4, the first transmitting board returns a command which is successfully received to the control and data processing board after the interruption of the first rising edge of R + is started by utilizing the parallel processing performance of the field programmable gate array, and the rest transmitting boards do not return commands;

s5, after the first rising edge is captured by the plurality of transmitting boards, the capturing of the rising edge on the R + signal line is closed, meanwhile, the timer is started to time, and T is passed₁After the time, the sound sources are simultaneously excited, and the signal synchronization among 4 transmitting plates at the transmitting end is ensured;

s6, after the MCU of the receiving main control board captures the first rising edge of R +, the pin corresponding to R + is reconfigured to be in the serial port communication mode, next communication is prepared, then the timer is started, and after T passes through₂After the time, sending a command for starting to collect the sound wave signal to the data collection circuit in a rising edge interruption mode;

s7, the data acquisition circuit acquires data with a specific length at a sampling rate of a certain frequency; the delta T ═ T of the data acquisition circuit after the sound source emits a sound wave signal₂-T₁The time begins to collect data.

Further, the number of the emitting plates is 4.

Further, in step S1, the parameters include an operation mode, a dead time, an excitation frequency, and a waiting time; the driving chip is an RS485 chip.

Further, in step S2, the capture frequency for the rising edge capture is set at 100MHz at the maximum.

Further, in step S3, the capture frequency of the first rising edge of the pair of emission plates R + is 25 MHz.

Further, in step S3, the capture frequency of the first rising edge of the pair R + by the transmitting board is the highest clock frequency of the field programmable gate array FPGA.

Further, in step S5, the precision of the timer is the clock precision of the crystal oscillator.

Furthermore, the signal synchronization precision is consistent with the crystal oscillator frequency, the maximum error is controlled within one crystal oscillator clock, and the precision requirement of acoustic logging is met.

The invention has the beneficial effects that:

1. the problem of signal synchronization of the transmitting end and the receiving end in the acoustic logging instrument is solved. The method provided by the invention can ensure that the synchronization precision is consistent with the crystal oscillator frequency, the maximum error is controlled within one crystal oscillator clock, and the precision requirement of acoustic logging is met.

2. And the hardware connection between the transmitting end and the receiving end is simplified. By using the method provided by the invention, the transmitting end and the receiving end can finish the data transmission and the signal synchronization only by two signal wires without additionally adding a signal wire as a synchronization signal. Meanwhile, the hardware connection of the transmitting end and the receiving end is consistent with the universal asynchronous serial port communication connection, the universal hardware can be compatible, and the hardware connection does not need to be changed.

3. High-voltage isolation between the transmitting end and the receiving end is realized. By using the method provided by the invention, the transmitting end and the receiving end are connected in an asynchronous serial port communication mode, and the transmitting end and the receiving end do not need to be grounded, so that the data acquisition and control of the receiving end cannot be influenced by a strong electric high-voltage signal generated by the transmitting end.

Drawings

Fig. 1 is a schematic diagram illustrating a principle of a method for synchronizing acoustic wave asynchronous serial port signals while drilling according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a hardware structure of a method for synchronizing while-drilling acoustic wave asynchronous serial port signals according to an embodiment of the present invention.

Fig. 3 is a schematic flowchart of a procedure of receiving a main control board in an embodiment.

Fig. 4 is a schematic flow chart of the procedure of the transmitting plate in the embodiment.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that technical features or combinations of technical features described in the following embodiments should not be considered as being isolated, and they may be combined with each other to achieve better technical effects. In the drawings of the embodiments described below, the same reference numerals appearing in the respective drawings denote the same features or components, and may be applied to different embodiments.

The technical problems solved by the invention are as follows:

synchronous serial communication requires clock signal ClK, ground signal GND, differential signal R +, R-four wires. Although the synchronous serial port communication can realize accurate synchronization of signals, high-voltage excitation signals generated when the transmitting end excites a sound source influence signal acquisition and data processing of the receiving end through GND signals because GND ground signals of the transmitting end and the receiving end are connected together; and 4 signal lines are needed for communication transmission in synchronous serial communication, while only 2 signal lines are needed for communication transmission in asynchronous serial communication adopted by the invention, thus simplifying hardware structure and reducing cost.

The invention relates to a method for synchronizing acoustic wave asynchronous serial port signals while drilling, which realizes communication and high-voltage signal isolation between a transmitting end and a receiving main control board by using an asynchronous serial port communication mode; the receiving control board is used as a main control end to configure parameters for the transmitting end in an asynchronous serial port communication mode and control excitation of a sound source; the transmitting terminal is an initiator of a synchronous sound source excitation signal; and the synchronization of signals is realized under the condition of asynchronous communication through the matching between the transmitting end and the receiving main control board. The principle of the invention is shown in fig. 1.

In this embodiment, the transmitting terminal includes 1 transmitting panel and 1 receiving main control board, receiving main control board is last to have little the control unit (MCU) and RS485 driver chip 1, has Field Programmable Gate Array (FPGA) and RS485 driver chip on the transmitting panel, 2, the Field Programmable Gate Array (FPGA) of transmitting panel and the little the control unit (MCU) of receiving main control board can both realize asynchronous serial communication's function. The transmitting board is connected with the receiving main control board through 2 differential signal lines R + and R-. The hardware architecture of the embodiment of the present invention is shown in fig. 2.

In one embodiment, the method of the present invention comprises the following steps:

s1, after the system is powered on, firstly receiving the configuration parameters of the 4 transmitting boards which are sequentially called by the micro control unit MCU of the main control board through the RS485 driving chip, wherein the configuration parameters comprise a working mode, dead time, excitation frequency and waiting time. And after the 4 transmitting boards successfully receive the configuration parameters, the 4 transmitting boards return the successfully received commands in sequence.

S2, receiving a command for exciting a sound source sent by a micro control unit MCU of the main control board to 4 transmitting boards in a broadcasting mode through an RS485 driving chip, simultaneously changing the configuration of a pin corresponding to R + of the micro control unit MCU from a serial port communication mode to a general input port mode, starting a rising edge interrupt function of the corresponding pin, preparing to capture the first rising edge of the corresponding pin caused by the command returned by the transmitting terminal, and setting the highest captured frequency at 100 MHz.

S3, after the 4 transmitting boards successfully receive the command of exciting the sound source, the 4 transmitting boards start to capture the first rising edge of R +, and the highest captured frequency is the clock frequency of the FPGA, generally at 25 MHz.

And S4, the transmitting board No. 1 returns a successfully received command to the control and data processing board after the interruption of the first rising edge of R + is started by utilizing the parallel processing performance of the FPGA, and the transmitting boards No. 2 to No. 4 do not return the command.

S5, after the first rising edge is captured by the 4 transmitting boards, the capture of the rising edge on the R + signal line is closed, meanwhile, the timer is started to time, and T is passed₁After time, monopole emission or 4-pole emission is realized according to received configuration parameters, different emission modes are realized, and 4 blocks at the emission end are ensuredThe signals between the transmitting plates are synchronous, and the precision of the timer is the clock precision of the crystal oscillator.

S6, after the MCU of the main control board captures the first rising edge of R +, the corresponding pin is reconfigured to be in the serial port communication mode to prepare for next communication, then the timer is started, and after T passes₂After the time, a command to start collecting the sound wave signal is sent to the data collecting circuit in a rising edge interruption mode.

S7, the data acquisition circuit acquires data with a specific length at a sampling rate of a certain frequency; the data acquisition circuit corresponds to Δ T (Δ T ═ T) after the sound source emits the sound wave signal₂-T₁) The time starts to collect data and Δ T can guarantee a sufficiently high accuracy.

In the above embodiments, the program flow of the receiving main control board is shown in fig. 3, and the program flow of the transmitting board is shown in fig. 4.

The invention realizes the transmission of data commands between the transmitting end and the receiving end and simultaneously realizes the isolation of high-voltage signals between the transmitting end and the receiving end in an asynchronous serial port communication mode. In the whole instrument, the receiving end is used as a main control to provide configuration parameters for the transmitting end in an asynchronous serial port communication mode and control the excitation of a sound source, but the transmitting end is used as an initiator of a synchronous sound source excitation signal. The synchronization of signals is realized under the hardware condition of asynchronous communication through the cooperation of the two. The purpose of signal synchronization through asynchronous communication is achieved by fully utilizing the parallel processing performance of the FPGA and the interrupt triggering function of the MCU.

While several embodiments of the present invention have been presented herein, it will be appreciated by those skilled in the art that changes may be made to the embodiments herein without departing from the spirit of the invention. The above examples are merely illustrative and should not be taken as limiting the scope of the invention.