PLC input and output module fatigue degree detection device and method

Abstract

The invention relates to a PLC input and output module fatigue degree detection device and method. The PLC input and output module fatigue degree detection device comprises a device base, a device backboard, a device main power supply access terminal, a device power supply module, a device switch, a device detection circuit integrated circuit board, a device action relay, a device load electromagnetic valve, a device load indicating lamp and a device test PLC and module. According to the invention, fatigue degree detection of PLC input and output modules of various models and brands can be satisfied, the detection device is concise in design, simple in installation and convenient to carry, and the integrated circuit board is arranged in the detection device, so that internal circuits of the detection device are effectively reduced, and the detection device is more stable and reliable to use. After a detection device switch is turned on, the detection device can complete a detection function, the influence of human factors on the detection result of the detection device is reduced to the greatest extent, and meanwhile, the detection method performs anomaly detection through detection times and response time, so that the result is more correct.

Description

Technical Field

[0001] The invention belongs to the technical field of PLC module detection, and in particular to a device and method for detecting fatigue degree of a PLC input and output module. Background Art

[0002] With the continuous advancement of science and technology, PLC (Programmable Logic Controller) has been widely used in various fields such as petroleum, chemical industry, steel, electric power, machinery manufacturing, building materials, transportation, environmental protection, etc. at home and abroad because of its multiple functions such as switch logic control, industrial process control, motion control, data processing, communication and networking, and its stability, reliability, outstanding safety, and programmable control when in use.

[0003] In various fields, PLC has become the core control device in production control. PLC rarely fails when working. Most of the failures are external sensing devices or lines. However, with the increase of service life, the onboard relays or optical isolators in the PLC input / output module may have aging problems such as inflexible contact action and virtual contact action. The signal of the PLC input / output module in a critical state is unstable, which will cause the controlled equipment to act sometimes and sometimes not. In severe cases, it may cause machine damage or quality accidents. The fault point of each failure will be different, and the fault handling time will also vary. Long-term fault handling will cause a great waste of manpower and material resources, which greatly affects the production efficiency and benefits of its application field. The traditional solution to this problem is to directly replace the PLC input / output module after it fails. This method belongs to post-processing in fault handling. The problematic PLC input / output module cannot be detected and diagnosed in advance, and the corresponding fault cannot be effectively controlled. In addition, the maintenance cost of directly replacing spare parts is relatively high. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and propose a PLC input and output module fatigue detection device and method, which can meet the fatigue detection of PLC input and output modules of various models and brands. The detection device is simple in design, simple to install, and easy to carry. The detection device is equipped with an integrated circuit board, which effectively reduces the internal circuits of the detection device and makes the detection device more stable and reliable. After turning on the detection device switch, the detection device can complete the detection function, which minimizes the influence of human factors on the detection results of the detection device. At the same time, the detection method performs abnormal detection through the number of detections and response time, making the results more accurate.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] A PLC input and output module fatigue detection device comprises a device base, a device backplane, a device main power access terminal, a device power module, a device switch, a device detection circuit integrated circuit board, a device action relay, a device load solenoid valve, a device load indicator light, and a device test PLC and module, wherein the device backplane integral connector is vertically mounted and fixed on the device base, the device main power access terminal, the device power module, the device switch, the device detection circuit integrated circuit board, the device action relay, the device load solenoid valve, the device load indicator light, and the device test PLC and module are all mounted on the device backplane; the device main power access terminal is connected to the device power module, the device main power access terminal is used to connect the main power supply, the device power module is used to convert the main power supply into a DC working voltage, the device switch is used to switch the device, and the device detection circuit integrated circuit board is used to detect the PLC input and output module.

[0007] Moreover, the device base includes a base end face and base legs, and base legs of equal length are welded to the four lower corners of the base end face respectively. The device back plate is vertically fixed to the base end face by connecting fixings on the base end face.

[0008] A detection method for a PLC input and output module fatigue detection device, characterized in that it comprises the following steps:

[0009] Step 1: Install the PLC of the brand to be tested and the input and output modules used for the test on the rack of the device test PLC and module installation location;

[0010] Step 2: Before testing, determine the PLC module to be tested. If the input module is to be tested, install an output module with normal functional status and test the input module through the output module. Otherwise, test the output module through the input module.

[0011] Step 3: After the PLC and the corresponding input and output modules used for the test are installed, turn on the device switch and test the power supply of each component of the device;

[0012] Step 4: Test the PLC input or output module to obtain the test result.

[0013] Furthermore, the step 4 comprises the following steps:

[0014] Step 4.1: A set of tests is conducted in three rounds, and three different voltage levels are selected according to the product performance of the PLC;

[0015] Step 4.2, perform the first round of testing, set the module voltage to the highest voltage value that the module can withstand, set the number of detections to 500 times, and start the test program;

[0016] Step 4.3: Perform the second round of testing, set the module voltage to the lowest voltage the module can withstand, set the number of tests to 500, and start the test program.

[0017] Step 4.4, conduct the third round of testing, set the module voltage to a fluctuating voltage, the voltage fluctuates continuously between the highest voltage value and the lowest voltage value that the module can withstand, set the number of detections to 500 times, and start the test program;

[0018] Step 4.5: Count the number of detections and response time, perform anomaly detection, and obtain the detection results.

[0019] Moreover, the abnormality detection in step 4 includes: performing abnormality detection by the number of detections and the response time respectively.

[0020] Moreover, the specific implementation method of performing anomaly detection by the number of detections is: performing anomaly detection on three rounds of detection data by using the probability density function of Gaussian distribution:

[0021] The probability density function based on Gaussian distribution is:

[0022]

[0023] Among them, μ is the data mean, σ is the standard form;

[0024]

[0025] In the formula of data mean and standard value, m is the number of test data, x is (i) is the i-th detection data value;

[0026] If f(x)<ε, then this point is an outlier; where ε is set to 1;

[0027] The first round of detection data values ​​are:

[0028] (x 1 (1) ,x 1 (2) ,x 1 (3) …x 1 (500) )

[0029] The second round of detection data values ​​are:

[0030] (x 2 (1) ,x 2 (2) ,x 2 (3) …x 2 (500) )

[0031] The third round of detection data values ​​are:

[0032] (x 3 (1) ,x 3 (2) ,x 3 (3) …x 3 (500) )

[0033] Substitute the three rounds of test data into the formula to find the corresponding probability density values, and then compare them with ε. If it is less than ε, it is an abnormality, which means that the module has failed the test. Otherwise, the module has passed the test.

[0034] Moreover, the specific implementation method of the abnormality detection by response time is: taking time as the x-axis and the number of acquisitions as the y-axis, performing discrete data statistics, calculating the linear regression function for detecting discrete data, and evaluating the stability of the response signal by the mean absolute error MAE parameter of the linear regression:

[0035] For discrete collection points, corresponding to x i of y i_true is the actual value, y i_pred is the predicted value of linear regression, then the linear regression absolute error MAE calculation method is:

[0036]

[0037] When the response time intervals of the collected discrete points are exactly the same, the discrete data will be completely distributed on a straight line with a fixed slope, and the actual value will be exactly the same as the predicted value; therefore, the closer the MAE is to 0, the more stable the signal response time is and the less fluctuations there are; horizontally comparing the slope values ​​of the linear regression functions of the three rounds of tests, the closer the slope values ​​are, the healthier the module performance is.

[0038] The advantages and positive effects of the present invention are:

[0039] The present invention constructs a PLC input-output module fatigue detection device through a device base, a device backplane, a device main power access terminal, a device power module, a device switch, a device detection circuit integrated circuit board, a device action relay, a device load solenoid valve, a device load indicator light, and a device test PLC and module. The present invention can meet the fatigue detection of PLC input-output modules of various models and brands. The detection device is simple in design, simple to install, and easy to carry. The detection device is equipped with an integrated circuit board, which effectively reduces the internal circuits of the detection device and makes the detection device more stable and reliable. After turning on the detection device switch, the detection device can complete the detection function, which minimizes the influence of human factors on the detection results of the detection device. At the same time, the detection method performs abnormal detection through the number of detections and the response time, so that the results are more correct. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a front view of the structure of the device of the present invention;

[0041] Figure 2 This is a front view of the integrated circuit board and circuit of the detection circuit of the device of the present invention;

[0042] Figure 3 It is a schematic diagram of the connection of the components of the integrated circuit board of the detection circuit of the device of the present invention;

[0043] Figure 4 It is the main view of the device detection PLC and module used in the present invention;

[0044] Figure 5 It is a flow chart of the method of using the present invention.

[0045] Description of labels:

[0046] 1-install the base; 2-install the back panel; 3-install the main power supply access terminal; 4-install the power module; 5-install the switch;

[0047] 6-device detection circuit integrated circuit board; 61-device detection circuit circuit board card; 62-device detection circuit circuit board connector;

[0048] 7-install action relay; 8-install load solenoid valve; 9-install load indicator light; 10-install detection PLC and module;

[0049] 101-device detects PLC power supply module; 102-device detects PLC central processing unit module; 103-device detects PLC input module; 104-device detects PLC output module. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below with reference to the accompanying drawings.

[0051] A PLC input and output module fatigue detection device, such as Figure 1 As shown, it includes a device base, a device backplane, a device main power access terminal, a device power module, a device switch, a device detection circuit integrated circuit board, a device action relay, a device load solenoid valve, a device load indicator light and a device test PLC and module, wherein the overall connector of the device backplane is vertically installed and fixed on the device base, and the device main power access terminal, the device power module, the device switch, the device detection circuit integrated circuit board, the device action relay, the device load solenoid valve, the device load indicator light and the device test PLC and module are all installed on the device backplane; the device main power access terminal is connected to the device power module, the device main power access terminal is used to connect the main power supply, the device power module is used to convert the main power supply into a DC working voltage, the device switch is used to switch the device, the device detection circuit integrated circuit board is used to detect the PLC input and output module, and the device base allows the entire device to be placed stably. When the device is running, the detection signal is fed back to the device detection PLC, and the fatigue degree of the PLC input / output module is judged by the PLC detection program, and then the on-board relay or optical isolator of the critical input / output module is replaced in time according to the detection result to ensure that the PLC input / output module is always in normal working condition.

[0052] like Figure 1 As shown, the device base 1 is made of 304 stainless steel, and consists of a base end face and base legs, and is installed at the bottom of the overall detection device. Base legs of equal length are welded on the four corners below the base end face, which can effectively increase the stability of the device base when placed. The device back plate 2 is vertically fixed to the base end face by connecting fixings on the base end face. The design of the device base can effectively ensure the stability of the overall placement of the device during use.

[0053] like Figure 1 and Figure 4 As shown, the device main power access terminal 3 is installed on the right side of the lowermost part of the device back panel 2. The AC 220V main power is connected to the device through the device main power access terminal and distributed to the device power module 4 and the device detection PLC power module 101. After conversion by each power module, the corresponding working voltage is provided for the overall operation of the device.

[0054] like Figure 1 As shown, the device power module 4 is installed between the device test PLC and module 10 and the device action relay 7 on the upper part of the device backplane 2, and is mainly used to convert the 220V AC main power supply into a DC working voltage that meets the operation of various components of the device.

[0055] like Figure 1As shown, the device switch 5 is installed on the left side of the lowermost part of the device back panel 2, and the device switch is opened and closed manually to realize the manual opening and closing functions of the device.

[0056] like Figure 1 , Figure 2 and Figure 3 As shown, the device detection circuit integrated circuit board 6 is installed on the left side of the device power module on the upper part of the device backplane, and is composed of a device detection circuit circuit board card 61 and a device detection circuit circuit board connector 62. The control connection circuit of the detection device is integrated on the circuit board card, and the circuits of various components of the detection device are connected to the circuit board through the connector on the circuit board. While reducing the internal control circuit of the device, the stability of the operation of the detection device is effectively guaranteed.

[0057] like Figure 1 As shown, the device action relay 7 is installed in the middle of the device back panel 2. After receiving the output signal of the PLC output module, the device action relay is actuated. After the relay is actuated, the device load solenoid valve 8 and the device load indicator light 9 are driven to operate. At the same time, the load action signal is fed back to the PLC input module through the auxiliary contacts of the device action relay to complete the control of the detection component of the detection device.

[0058] like Figure 1 As shown, the device load solenoid valve 8 is installed at the lower part of the device back plate 2. The access of the load solenoid valve can ensure the stable and reliable operation of the entire circuit of the detection device.

[0059] like Figure 1 As shown, the device load indicator light 9 is installed on the device load solenoid valve 8. When the device load solenoid valve is actuated, the device load indicator light is on, otherwise the light is off, which can intuitively display the action status of the device load solenoid valve.

[0060] like Figure 1 and Figure 4 As shown, the device test PLC and module 10 is installed at the uppermost part of the device back panel 2, and is composed of a device detection PLC power module 101, a device detection PLC central processor module 102, a device detection PLC input module 103, and a device detection PLC output module 104. The brand or model of the device test PLC and module can be replaced according to user needs to realize the detection function of various brands or models of PLC device modules, and at the same time realize PLC program control and PLC program detection of various components of the detection device.

[0061] A detection method for a PLC input and output module fatigue detection device, such as Figure 5 As shown, the following steps are included:

[0062] Step 1: Install the PLC of the brand to be tested and the input and output modules used for the test on the rack of the device test PLC and module installation location;

[0063] Step 2: Before testing, determine the PLC module to be tested. If the input module is to be tested, install an output module with normal functional status and test the input module through the output module. Otherwise, test the output module through the input module.

[0064] Step 3: After the PLC and the corresponding input and output modules used for the test are installed, turn on the device switch and test the power supply of each component of the device;

[0065] Step 4: Test the PLC input or output module to obtain the test result.

[0066] Step 4.1: A set of tests is conducted in three rounds, and three different voltage levels are selected according to the product performance of the PLC;

[0067] Step 4.2, perform the first round of testing, set the module voltage to the highest voltage value that the module can withstand, set the number of detections to 500 times, and start the test program;

[0068] Step 4.3: Perform the second round of testing, set the module voltage to the lowest voltage the module can withstand, set the number of tests to 500, and start the test program.

[0069] Step 4.4, conduct the third round of testing, set the module voltage to a fluctuating voltage, the voltage fluctuates continuously between the highest voltage value and the lowest voltage value that the module can withstand, set the number of detections to 500 times, and start the test program;

[0070] Step 4.5: Count the number of detections and the response time, perform anomaly detection, and obtain the detection result. The anomaly detection in step 4.5 includes: performing anomaly detection by respectively performing the number of detections and the response time.

[0071] The specific implementation method of anomaly detection by detection times is: anomaly detection is performed on three rounds of detection data through the probability density function of Gaussian distribution:

[0072] The probability density function based on Gaussian distribution is:

[0073]

[0074] Among them, μ is the data mean, σ is the standard form;

[0075]

[0076] In the formula of data mean and standard value, m is the number of test data, x is (i)is the i-th detection data value;

[0077] If f(x)<ε, then this point is an abnormal point; ε is set to 1, which means there is no abnormal situation;

[0078] The first round of detection data values ​​are:

[0079] (x 1 (1) ,x 1 (2) ,x 1 (3) …x 1 (500) )

[0080] The second round of detection data values ​​are:

[0081] (x 2 (1) ,x 2 (2) ,x 2 (3) …x 2 (500) )

[0082] The third round of detection data values ​​are:

[0083] (x 3 (1) ,x 3 (2) ,x 3 (3) …x 3 (500) )

[0084] Substitute the three rounds of test data into the formula to find the corresponding probability density values, and then compare them with ε. If it is less than ε, it is an abnormality, which means that the module has failed the test. Otherwise, the module has passed the test.

[0085] The specific implementation method of anomaly detection through response time is: with time as the x-axis and the number of acquisitions as the y-axis, discrete data statistics are performed, the linear regression function for detecting discrete data is calculated, and the stability of the response signal is evaluated by the mean absolute error MAE parameter of linear regression:

[0086] For discrete collection points, corresponding to x i of y i_true is the actual value, y i_pred is the predicted value of linear regression, then the linear regression absolute error MAE calculation method is:

[0087]

[0088] When the response time intervals of the collected discrete points are exactly the same, the discrete data will be completely distributed on a straight line with a fixed slope, and the actual value will be exactly the same as the predicted value; therefore, the closer the MAE is to 0, the more stable the signal response time is and the less fluctuations there are; horizontally comparing the slope values ​​of the linear regression functions of the three rounds of tests, the closer the slope values ​​are, the healthier the module performance is.

[0089] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A PLC input and output module fatigue detection device, characterized in that: It includes a device base, a device backplane, a device main power access terminal, a device power module, a device switch, a device detection circuit integrated circuit board, a device action relay, a device load solenoid valve, a device load indicator light, and a device test PLC and module, wherein the device backplane integral connector is vertically installed and fixed on the device base, and the device main power access terminal, the device power module, the device switch, the device detection circuit integrated circuit board, the device action relay, the device load solenoid valve, the device load indicator light, and the device test PLC and module are all installed on the device backplane; the device main power access terminal is connected to the device power module, and the device main power access terminal is used to connect the main power supply, the device power module is used to convert the main power supply into a DC working voltage, the device switch is used to switch the device, and the device detection circuit integrated circuit board is used to detect the PLC input and output module.

2. A PLC input-output module fatigue detection device according to claim 1, characterized in that: The device base comprises a base end face and base legs, and base legs of equal length are respectively welded on the four lower corners of the base end face, and the device back plate is vertically fixed on the base end face by connecting fixings on the base end face.

3. A detection method for a PLC input / output module fatigue detection device as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Install the PLC of the brand to be tested and the input and output modules used for the test on the rack of the device test PLC and module installation location; Step 2: Before testing, determine the PLC module to be tested. If the input module is to be tested, install an output module with normal functional status and test the input module through the output module. Otherwise, test the output module through the input module. Step 3: After the PLC and the corresponding input and output modules used for the test are installed, turn on the device switch and test the power supply of each component of the device; Step 4: Test the PLC input or output module to obtain the test result.

4. The detection method of a PLC input-output module fatigue detection device according to claim 3 is characterized in that: The step 4 comprises the following steps: Step 4.1: A set of tests is conducted in three rounds, and three different voltage levels are selected according to the product performance of the PLC; Step 4.2, perform the first round of testing, set the module voltage to the highest voltage value that the module can withstand, set the number of detections to 500 times, and start the test program; Step 4.3: Perform the second round of testing, set the module voltage to the lowest voltage the module can withstand, set the number of tests to 500, and start the test program. Step 4.4, conduct the third round of testing, set the module voltage to a fluctuating voltage, the voltage fluctuates continuously between the highest voltage value and the lowest voltage value that the module can withstand, set the number of detections to 500 times, and start the test program; Step 4.5: Count the number of detections and response time, perform anomaly detection, and obtain the detection results.

5. The detection method of a PLC input-output module fatigue detection device according to claim 4, characterized in that: The abnormality detection in step 4 includes: performing abnormality detection by detection times and response time respectively.

6. The detection method of a PLC input-output module fatigue detection device according to claim 5, characterized in that: The specific implementation method of performing anomaly detection by the number of detections is: performing anomaly detection on three rounds of detection data by using the probability density function of Gaussian distribution: The probability density function based on Gaussian distribution is: Among them, μ is the data mean, σ is the standard form; In the formula of data mean and standard value, m is the number of test data, x is (i) is the i-th detection data value; If f(x) < ε, then this point is an outlier; ε is set to 1; The first round of detection data values ​​are: (x1 (1) ,x1 (2) ,x1 (3) …x1 (500) ) The second round of detection data values ​​are: (x2 (1) ,x2 (2) ,x2 (3) …x2 (500) ) The third round of detection data values ​​are: (x3 (1) ,x3 (2) ,x3 (3) …x3 (500) ) Substitute the three rounds of test data into the formula to find the corresponding probability density values, and then compare them with ε. If it is less than ε, it is an abnormality, which means that the module has failed the test. Otherwise, the module has passed the test.

7. The detection method of a PLC input-output module fatigue detection device according to claim 5, characterized in that: The specific implementation method of abnormality detection by response time is: taking time as the x-axis and the number of acquisitions as the y-axis, performing discrete data statistics, calculating the linear regression function for detecting discrete data, and evaluating the stability of the response signal by the mean absolute error MAE parameter of linear regression: For discrete collection points, the y corresponding to xi i_true is the actual value, y i_pred is the predicted value of linear regression, then the linear regression absolute error MAE calculation method is: When the response time intervals of the collected discrete points are exactly the same, the discrete data will be completely distributed on a straight line with a fixed slope, and the actual value will be exactly the same as the predicted value; therefore, the closer the MAE is to 0, the more stable the signal response time is and the less fluctuations there are; horizontally comparing the slope values ​​of the linear regression functions of the three rounds of tests, the closer the slope values ​​are, the healthier the module performance is.

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