CN-121995191-A - Circuit board fault detection positioning method suitable for logging instrument

Abstract

The invention discloses a fault detection positioning method suitable for a logging instrument circuit board, which comprises the following specific steps of 1, setting a plurality of key detection points on a perfect standard circuit board, building a logging instrument circuit board fault detection device, 2, building a standard circuit board waveform chart library, adopting the logging instrument circuit board fault detection device in the 1 to carry out real-time test, comparing and analyzing with the standard circuit board waveform chart library, analyzing the logic sequence and the relation of each key detection point, building a logic judgment fault diagnosis table based on a truth table, effectively determining the fault point, and accurately judging the fault point and a fault component if the measurement point is more refined. The invention solves the problems of difficult diagnosis of the circuit board and low fault recognition rate of the traditional fault detection method of the circuit board of the logging instrument, and has simple operation and higher safety.

Inventors

• LU JINGWU
• YAN RUIFENG
• SUN GUIQING
• BAI RUI
• JIA XIN
• SHI HAORAN
• XU CHUNTAO

Assignees

• 中国石油天然气集团有限公司
• 中国石油集团测井有限公司

Dates

Publication Date

20260508

Application Date

20241104

Claims (7)

1. 1. The fault detection and positioning method suitable for the logging instrument circuit board is characterized by comprising the following steps of: step 1, setting a plurality of key detection points on a perfect standard circuit board, and constructing a fault detection device of the circuit board of the logging instrument; Step 2, a standard circuit board waveform chart library is established, the logic sequence and the relation of each key detection point are analyzed, and a logic judgment fault diagnosis table based on a truth table is established; and step 3, adopting the fault detection device of the logging instrument circuit board in the step 1 to perform real-time test, comparing and judging with a standard circuit board waveform chart library, effectively determining a fault point by utilizing a fault diagnosis table, and if the number of the measuring points is increased and the logic relationship is thinned, judging the fault point and fault components more accurately.
2. 2. The fault detection and positioning method for the circuit board of the logging instrument according to claim 1, wherein the fault detection device for the circuit board of the logging instrument is characterized in that an input end of a circuit module of a key detection point is respectively connected with a circuit board working power supply module and an input signal source module, an output end of the circuit module of the key detection point is connected with output signal processing units of a plurality of branches, the output signal processing units of each branch are respectively connected with a digital acquisition unit, and the digital acquisition units are respectively connected with expert software and the input signal source module and the output signal processing module.
3. 3. The method for detecting and positioning faults of a circuit board of a logging instrument according to claim 2, wherein step 2 is characterized in that before the circuit board is detected, a standard circuit board information base is called, key detection point information, operation control information and key detection point standard waveforms are loaded, key detection point signal waveforms are checked one by one according to the loaded operation sequence, records are acquired, the acquired waveforms are compared with waveforms of key detection points corresponding to the standard board, and whether the signal waveforms of the selected key detection points are normal is judged manually.
4. 4. The method for detecting and positioning faults of a circuit board of a logging instrument according to claim 3, wherein when the waveform of a key detection point of the circuit board in the step 2 is abnormal compared with the waveform of the point of a standard library, the circuit corresponding to the relevant part of the detection point of the circuit board is problematic, the corresponding abnormality occurs when one or more devices are in fault, if the specific device fault is to be distinguished, screening detection is carried out by combining the relevant multiple devices around the corresponding detection point of the circuit diagram, and the fault point or the fault device is finally found by removing components or circuit bypasses with perfect working states through multipoint measurement.
5. 5. The method of claim 2, wherein the circuit board operating power modules are low voltage power supplies, typically one or more of ± 15VA, ± 12VA, ± 9VA, ± 5VA, 5VD and 3.3 VD.
6. 6. The fault detection and positioning method for the circuit board of the logging instrument according to claim 5, wherein the input signal source module adopts a programmable signal generator to edit various needed waveforms on line, and the output signal processing unit modulates the signals output by the circuit board according to the input voltage requirement of the AD acquisition module.
7. 7. The fault detection and positioning method for the logging instrument circuit board according to claim 6, wherein the digital acquisition unit adopts a digital oscilloscope to digitize waveforms output by the circuit board, and expert software adopts a real-time analysis system to display, record and manage the digitized signals, so that the programmable signal generator, the digital oscilloscope and the real-time analysis system are integrally connected into the logging instrument circuit board fault detection device.

Description

Circuit board fault detection positioning method suitable for logging instrument Technical Field The invention belongs to the technical field of logging equipment, and particularly relates to a fault detection and positioning method suitable for a circuit board of a logging instrument. Background Logging instruments are electromechanical integrated devices which measure lithology of formations by using methods such as acoustic waves, resistivity, radioactivity and the like, and judge and determine reservoirs of oil and gas. The logging instrument comprises various controllable circuit boards, the normal operation of the circuit boards is the guarantee of the logging measurement data to be correct and reliable, and how to detect the working state of the circuit boards is very important. The structure of the logging instrument is limited by the working environment such as the well bore structure, the well bore temperature and the pressure, and the logging instrument is in a slender cylindrical shape, so that the movement measurement in the well is facilitated. In order to resist the influence of well depth pressure and temperature, the casing of the logging instrument is of a sealed cylindrical steel pipe structure, and a metal framework structure is utilized for fixing and protecting a circuit board. Due to the design of the circuit, which is limited by the appearance of the logging instrument, more than 90% of the circuit boards are rectangular in shape, and the design of the circuit tends to be modularized along with the development of integrated circuits, and standard connector connection is used between the boards. The logging instrument can be damaged in the use process, the failed circuit board can be detached from the instrument and sent to a maintenance station for detection, the maintenance station needs to test according to the functions of the circuit board, a failure point is found, and the circuit board is repaired by means of replacing components and the like. The existing circuit board needs to be installed in an instrument, power is supplied through the ground, a universal meter and an oscilloscope are used for checking the voltage and the waveform of a working point according to a circuit diagram, a circuit board is repaired, a plurality of devices and meters are needed, in addition, the circuit diagram is needed to be understood, the principle is understood, the maintenance difficulty is high, and the time effect is low. The existing fault detection technology of the circuit board of the logging instrument mainly uses image recognition and infrared imaging technology to determine a fault area, and improves the yield of the circuit board. Chinese patent (application date: 2021.06.28; application number: CN202110717896.5; publication date: 2021.09.17; publication number: CN 113409284A) discloses a method, a device, equipment and a storage medium for detecting faults of a circuit board, and relates to the fields of cloud computing and computer vision. The method comprises the steps of obtaining a microscopic image of a circuit board, determining a candidate fault area according to the microscopic image and a pre-trained image recognition model, determining a test input node and a test output node according to the candidate fault area, responding to input test excitation to the test input node, analyzing output signals of the test output node, determining a fault feature vector, and predicting fault information of the circuit board based on the fault feature vector and the pre-trained fault prediction model, wherein the fault prediction model is used for representing the corresponding relation between the feature vector and the fault information. The Chinese patent (2017.12.28 in the application date; CN201711457859.5 in the application date; 2018.06.12 in the publication date; CN 108152712A) discloses a circuit board fault detection method, which comprises the steps of setting the power-on time length and the power-down detection time length, setting the cycle number M for obtaining infrared energy data and/or the frequency N for obtaining infrared energy data in each cycle, obtaining the infrared energy data in M cycles of each pixel point of a test circuit board, obtaining the infrared energy data in N power-on peak values in each cycle and the infrared energy data in N power-down periods, subtracting the N power-on peak values in each cycle from the infrared energy data in N power-down periods respectively, then accumulating the N subtraction results in each cycle, accumulating the results in M cycles to obtain difference infrared energy data, carrying out the same treatment on the standard circuit board to obtain difference infrared energy data, and carrying out the comparison between the difference infrared energy data in each pixel point of the test circuit board and the difference infrared energy data in each pixel point of the test circuit board. In the existing fault detection method