Railway turnout locking force test system and test method

Abstract

The invention relates to a railway turnout locking force test system and test method. The invention aims to solve the technical problem that the inherent conversion resistance attribute of the point rail is insufficiently concerned in the prior art. According to the technical scheme, an adjusting gasket is arranged on the top face of locking iron, the locking iron is fixed in a locking frame through a bolt, a first stress piece and a third stress piece are symmetrically arranged on the two sides of a wiring groove in the top face of the adjusting gasket in the main strain direction, and a second stress piece and a fourth stress piece are symmetrically arranged on the two sides of the wiring groove in the auxiliary strain direction. A fifth stress piece, a seventh stress piece, a sixth stress piece and an eighth stress piece are arranged on the back face of the adjusting gasket, and the stress pieces are electrically connected with the communication module. According to the invention, the strain gauge is used as a sensor to collect data, so that the labor force can be effectively reduced, the collected data is more real-time, the collection efficiency is also obviously improved, and the switch machine conversion resistance realizes the conversion from passive detection to pilot detection.

Description

Technical Field

[0001] The present invention belongs to the technical field of turnout switching, and in particular relates to an intelligent test system and method for turnout switching resistance. Background Art

[0002] With the rapid development of railway transportation, operational safety and reliability have attracted widespread attention. As a key component of railway lines, the operational status of turnout systems is directly related to train safety. Locking force is a core parameter for evaluating turnout performance. Real-time and accurate monitoring of locking force is crucial for ensuring railway transportation safety and providing early warning of turnout system failures.

[0003] Existing turnout tests all measure the turnout switching force. However, the main purpose of testing according to the rated switching force index is to ensure that the switch machine used can switch the switch rail and the heart rail. It focuses more on the performance of the switch machine itself and pays insufficient attention to the inherent switching resistance properties of the switch rail and the heart rail. Summary of the Invention

[0004] The purpose of the present invention is to solve the above technical problems and provide an intelligent test system and test method for turnout switching resistance.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] An intelligent test system for switch switching resistance includes a sample device, a test system, and a calibration system. The sample device is provided with an adjustment gasket on the top surface of a locking iron, and the locking iron is fixed in a locking frame by bolts. Stress gauges 1 and 3 are symmetrically provided on both sides of a wiring groove on the top surface of the adjustment gasket along the main strain direction. Stress gauges 2 and 4 are symmetrically provided on both sides of the wiring groove along the secondary strain direction. The main strain direction is the direction of the longitudinal tension exerted on the locking iron, and the secondary strain direction is the direction of the transverse shear force. Stress gauges 5, 7, 6, and 8 are respectively provided on the back surface of the adjustment gasket at positions corresponding to stress gauges 1, 3, 2, and 4. The strain gauges are electrically connected to each other by wires passing through the wiring groove.

[0007] The calibration system includes a microcomputer-controlled electronic universal testing machine and a fixture, the microcomputer-controlled electronic universal testing machine is electrically connected to the test system, the fixture includes an upper fixture and a lower fixture, the upper end of the upper fixture is connected to the upper end of the microcomputer-controlled electronic universal testing machine via a pin shaft, the bottom of the upper fixture matches the bottom of the locking iron, the lower end of the lower fixture is connected to the lower end of the microcomputer-controlled electronic universal testing machine via a pin shaft, and the top surface of the lower fixture supports the adjustment gasket;

[0008] In the test system, the strain gauge is electrically connected to the communication module, and the communication module includes a terminal stress acquisition unit, serial port acquisition software and a host computer. The strain gauge is electrically connected to the terminal stress acquisition unit, the terminal stress acquisition unit is electrically connected to the serial port acquisition unit, and the host computer is electrically connected to the serial port acquisition unit. The terminal stress acquisition unit acquires data and transmits it to the serial port acquisition unit, and then transmits the data to the host computer for calculation and processing.

[0009] Furthermore, all strain gauges are connected using a full-bridge circuit.

[0010] Furthermore, the output end of the full-bridge circuit is connected to a high-impedance signal amplifier.

[0011] A method for intelligently testing switch switching resistance includes the following steps:

[0012] Step 1) Stress gauges 1 to 8 collect strain values generated during the operation of the switch machine, and use a full-bridge circuit to convert the collected strain signals into electrical signals. The symmetrical layout of the full-bridge circuit offsets the strain drift caused by the different operating temperatures of the locking iron outdoors;

[0013] Step 2) The high-impedance signal amplifier amplifies the measured tiny signal to an electrical signal within the 5V range, and the A / D converter in the communication module converts the analog signal into a digital signal;

[0014] Step 3) Apply serial communication technology, use the MAX232 chip to achieve level conversion, and then use RS-232 to USB to communicate with the PC. The microcontroller transmits the data collected by each node to the host computer through the serial port, and the data is analyzed and diagnosed;

[0015] Step 4) Calibrate the collected electrical signals and the applied tension value, and establish a calibration curve based on the linear relationship between the strain gauge layout and the tension value to facilitate data analysis and processing on the host computer.

[0016] Furthermore, the specific process of the calibration test in step 4) is as follows:

[0017] Step 4.1) Clamp both ends of the specimen assembly with fixtures and mount it on a computer-controlled electronic universal testing machine. Use a laser level to check and fine-tune the upper and lower fixtures to ensure they are completely perpendicular to the horizontal, ensuring that the axis of force applied to the sensor aligns with the axis of force applied to the press.

[0018] Step 4.2) Initial value reset: After installation, there will be an initial pressure value in the test system due to preload. Use the reset button on the collector to reset the pressure value to 0.

[0019] After step 4.3) preparations are complete, connect the main power supply and preheat the sample device for one hour;

[0020] Step 4.4) Set the microcomputer-controlled electronic universal testing machine to zero load and ensure that the high-precision sensor built into the press is in its initial state;

[0021] Step 4.5) Use the zeroing option on the data collector to reset the strain gauge output to zero, ensuring there is no locking force output.

[0022] Step 4.6) Conduct a tensile test, which consists of a loading phase and an unloading phase. During the loading phase, load the load at a rate of 0.05 kN / s for each 1.5 kN load, then hold for 30 seconds until the load reaches 15 kN. Then, enter the unloading phase, unload the load at a rate of 0.05 kN / s for each 3 kN load, then hold for 30 seconds until the load reaches 0 kN.

[0023] Step 4.7) After returning to zero load, hold for 1 minute, read the zero output value, and repeat step 4.6) six times;

[0024] Step 4.8) Analyze the exported data. Using wavelet decomposition, the different frequency components of the data are decomposed. By retaining the detailed information of the low-frequency part and suppressing or removing the noise in the high-frequency part, the signal is denoised.

[0025] Step 4.9) Select the curve with the lowest linearity among the six data curves output in step 4.7) as the research object, and compare the processed reconstructed signal graph with the output signal of the standard force sensor;

[0026] Step 4.10) Take the average value of the different force holding stages and plot a two-dimensional graph of the average value of the holding stage and the pressure value of the standard force sensor at the current moment to form the characteristic curve of the locking force sensor.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention provides an adjustment shim on the locking iron and arranges strain gauges on the upper and lower surfaces of the adjustment shim in the primary and secondary strain directions to collect the strain values generated by the locking iron connection shim of the switch during operation. This allows the switching locking force to be tested without changing the original switch structure.

[0029] 2. The present invention adopts a communication module to collect voltage signals, uses a MAX232 chip to realize level conversion, and then uses RS-232 to USB to realize communication with the PC end, and realizes intelligent online monitoring of the conversion locking force value through serial communication;

[0030] 3. The present invention can transmit data to the host computer through the single chip microcomputer for technical personnel to perform data analysis and diagnosis, so as to prevent turnout equipment failure and avoid greater economic losses and safety accidents;

[0031] 4. The present invention uses strain gauges as sensors to collect data, which can effectively reduce labor, and the collected data is more real-time, and the collection efficiency is significantly improved. The switch machine conversion resistance has achieved a transformation from passive detection to leading detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the present invention;

[0033] Figure 2 This is a schematic diagram of the top surface structure of the adjusting gasket of the present invention;

[0034] Figure 3 This is a schematic diagram of the bottom surface structure of the adjusting gasket of the present invention;

[0035] Figure 4 Schematic diagram of the full-bridge circuit structure of the present invention;

[0036] Figure 5 It is a schematic diagram of the signal acquisition process of the present invention;

[0037] Figure 6 Schematic diagram of the node communication mechanism of the present invention;

[0038] Figure 7 Schematic diagram of the fixture structure of the present invention;

[0039] Figure 8 This is a curve diagram of the locking force strain gauge test data of the present invention;

[0040] Figure 9 It is a wavelet decomposition curve diagram of the locking force signal of the present invention;

[0041] Figure 10 A reconstructed signal curve diagram of the locking force strain gauge of the present invention;

[0042] Figure 11 This is a curve chart of the calibration test results of the locking force strain gauge of the present invention;

[0043] Figure 12 is a characteristic curve diagram of the locking force strain gauge of the present invention;

[0044] Figure 13 is the residual interval leverage diagram of the present invention;

[0045] In the figure: 1-adjusting gasket; 2-locking iron; 3-stress plate one; 4-stress plate two; 5-stress plate three; 6-stress plate four; 7-wiring trough; 8-stress plate five; 9-stress plate six; 10-stress plate seven; 11-stress plate eight; 12-upper fixture; 13-lower fixture. DETAILED DESCRIPTION

[0046] The present invention will be further described below with reference to the embodiments and the accompanying drawings.

[0047] like Figure 1-6 As shown, an intelligent test system for turnout switching resistance includes a sample device, a test system and a calibration system. The sample device is provided with an adjustment gasket 1 on the top surface of the locking iron 2, and the locking iron 2 is fixed in the locking frame by bolts. Stress gauges 1 3 and 3 5 are symmetrically provided on both sides of the wiring groove 7 on the top surface of the adjustment gasket 1 along the main strain direction. Stress gauges 2 4 and 4 6 are symmetrically provided on both sides of the wiring groove 7 along the secondary strain direction. The main strain direction is the direction of the longitudinal tension exerted on the locking iron 2, and the secondary strain direction is the direction of the transverse shear force. Stress gauges 5 8, 7 10, 6 9 and 8 11 are respectively provided on the back of the adjustment gasket 1 at positions corresponding to stress gauges 1 3, 3 5, 2 4 and 4 6. The strain gauges are electrically connected by wires passing through the wiring groove 7. All strain gauges are connected by a full-bridge circuit, and the output end of the full-bridge circuit is connected to a high-impedance signal amplifier.

[0048] The calibration system includes a microcomputer-controlled electronic universal testing machine and a fixture. The microcomputer-controlled electronic universal testing machine is electrically connected to the test system. The fixture includes an upper fixture 12 and a lower fixture 13. The upper end of the upper fixture 12 is connected to the upper end of the microcomputer-controlled electronic universal testing machine through a pin shaft. The bottom of the upper fixture 12 matches the bottom of the locking iron 2. The lower end of the lower fixture 13 is connected to the lower end of the microcomputer-controlled electronic universal testing machine through a pin shaft. The top surface of the lower fixture 13 supports the adjustment gasket 1.

[0049] In the test system, the strain gauge is electrically connected to the communication module, and the communication module includes a terminal stress acquisition unit, serial port acquisition software and a host computer. The strain gauge is electrically connected to the terminal stress acquisition unit, the terminal stress acquisition unit is electrically connected to the serial port acquisition unit, and the host computer is electrically connected to the serial port acquisition unit. The terminal stress acquisition unit acquires data and transmits it to the serial port acquisition unit, and then transmits the data to the host computer for calculation and processing.

[0050] A method for intelligently testing switch switching resistance includes the following steps:

[0051] Step 1) Stress gauges 1-3 through 8-11 collect strain values generated during the operation of the switch machine, and use a full-bridge circuit to convert the collected strain signals into electrical signals. The symmetrical layout of the full-bridge circuit offsets strain drift caused by the different operating temperatures of the locking iron 2 outdoors.

[0052] Step 2) The high-impedance signal amplifier amplifies the measured tiny signal to an electrical signal within the 5V range, and the A / D converter in the communication module converts the analog signal into a digital signal;

[0053] Step 3) Apply serial communication technology, use the MAX232 chip to achieve level conversion, and then use RS-232 to USB to communicate with the PC. The microcontroller transmits the data collected by each node to the host computer through the serial port, and the data is analyzed and diagnosed;

[0054] Step 4) Calibrate the collected electrical signals and applied tension values. A calibration curve is established based on the linear relationship between the strain gauge layout and the tension value to facilitate data analysis and processing on the host computer. The specific process is as follows:

[0055] Step 4.1) Clamp both ends of the specimen assembly with fixtures and install it on a computer-controlled electronic universal testing machine. Use a laser level to check and fine-tune the upper and lower fixtures to ensure they are completely perpendicular to the horizontal. Ensure that the axis of force applied to the sensor coincides with the axis of force applied to the press to avoid offsetting the sensor's measurement results due to external mechanical forces or incorrect sensor installation.

[0056] Step 4.2) Initial value reset: After installation, there will be an initial pressure value in the test system due to preload. Use the reset button on the collector to reset the pressure value to 0.

[0057] After step 4.3) preparations are complete, connect the main power supply to the sample device and preheat it for one hour to ensure there is no interference from factors such as ambient temperature changes, humidity changes, electromagnetic interference, vibration, unstable power supply, and external electromagnetic radiation;

[0058] Step 4.4) Set the microcomputer-controlled electronic universal testing machine to zero load and ensure that the high-precision sensor built into the press is in its initial state;

[0059] Step 4.5) Use the zeroing option on the data collector to reset the strain gauge output to zero, ensuring there is no locking force output.

[0060] Step 4.6) Conduct a tensile test, which consists of a loading phase and an unloading phase. During the loading phase, load the load at a rate of 0.05 kN / s for each 1.5 kN load, then hold for 30 seconds until the load reaches 15 kN. Then, enter the unloading phase, unload the load at a rate of 0.05 kN / s for each 3 kN load, then hold for 30 seconds until the load reaches 0 kN.

[0061] Table 1 Tensile force calibration test data

[0062]

[0063] Step 4.7) After returning to zero load, hold for 1 minute, read the zero output value, and repeat step 4.6) six times;

[0064] Step 4.8) Analyze the exported data and collect data such as Figure 8 As shown in the figure, the amplitude of the test curve of the locking force strain gauge fluctuates significantly during the unloading phase. This may be due to the hysteresis effect of the strain gauge during the unloading process, that is, the strain gauge response is out of sync with the actual force change. This hysteresis can cause the sensor to experience amplitude fluctuations during the unloading process, which is particularly noticeable under rapidly changing force signals. During the unloading process, friction may occur at the contact surface between the fixture and the strain gauge. This friction force may be unstable with changes in force. Especially when the force approaches zero, the friction force may change or become uneven, causing signal fluctuations.

[0065] At the beginning of the unloading phase, a large amplitude fluctuation occurs, indicated by the green area at the top of the graph. This may be due to the nonlinear response of the strain gauge under high load and unloading. If the strain gauge's characteristics under high load are not completely linear, the change in force at the beginning of unloading may cause instability in the strain gauge output, resulting in fluctuations.

[0066] Depend on Figure 8 It can be seen that electrical noise, vibration and other physical interference sources may interfere with the strain gauge output, and the interference must be eliminated before calibration data can be collected from the test data.

[0067] Wavelet transform is a commonly used signal denoising method. Through wavelet decomposition, the different frequency components of the signal will be decomposed. By retaining the detailed information of the low-frequency part and suppressing or removing the noise in the high-frequency part, the signal denoising is achieved; the low-frequency part reflects the smooth characteristics of the signal, while the high-frequency part is more associated with instantaneous changes and noise. By performing appropriate threshold processing or reconstruction on the high-frequency coefficients, the noise can be effectively removed, the main information of the signal can be retained, and the quality of the signal can be improved.

[0068] First, the measured data is decomposed by wavelet, and the results are as follows: Figure 9 As shown in the figure, s is the original signal, a5 is the trend term, and d1~d5 are the fluctuation terms. As can be seen from the figure, the waveform of the trend term a5 is basically the fluctuation center line of the original signal s, and the interference is effectively removed. Therefore, this embodiment uses the filtered trend term as the measured signal, as shown in FIG. Figure 10 shown.

[0069] Step 4.9) Select the curve with the lowest linearity among the six data curves output in step 4.7) as the research object, and compare its processed reconstructed signal graph with the output signal of the standard force sensor. The results are as follows Figure 9-11 As shown;

[0070] The calibration test results show that the locking force strain gauge can effectively and in real time reflect the change of locking force as the locking iron 2 is stressed, and can remain near the horizontal line when the applied force remains unchanged. After the loading is completed, it can return to zero again. The pressure change curve output by it is highly consistent with the signal measured by the standard pressure sensor. When the force changes, the standard sensor in the tensile machine and the locking force strain gauge change almost simultaneously. Figure 11 As can be seen in the figure, the force measured by the strain gauge is slightly ahead of the force. The reason is that there may be friction or resistance between the fixture and the strain gauge, which will affect the speed of force transmission. If there is friction or adhesion between the materials when the fixture contacts the strain gauge, the force transmission may be ahead of the force.

[0071] Step 4.10) Take the average value of the different force holding stages and plot a two-dimensional graph of the average value of the holding stage and the pressure value of the standard force sensor at the current moment to form the characteristic curve of the locking force sensor.

[0072] After the calibration test of the locking iron 2 strain gauge is completed, the performance test of the strain gauge force can be further carried out. In the railway turnout switching system, the linearity and repeatability of the strain gauge are of particular concern. The average value of the different force holding stages is taken, and a two-dimensional graph is drawn between the average value of the holding stage and the pressure value of the standard force sensor at the current moment, which is the characteristic curve of the locking force strain gauge. Figure 12 shown.

[0073] according to Figure 12 After analyzing the characteristic curve, it can be seen that there is a good linear relationship between the strain gauge output signal and the actual load. The maximum residual value of the regression analysis is 201.3023N. Dividing it by the maximum range of the sensor 15000 N, the linearity of the sensor is 1.34%. Since the requirement of this project is 3%, the linearity and measurement accuracy of this strain gauge can meet the requirements of this project.

[0074] This embodiment uses a linear regression model to represent the relationship between the output of the locking force strain gauge and the standard sensor. The residual plot can be used to check the quality of the fit. By checking whether the residual plot shows obvious regularity or trend, it can be determined whether the model has successfully fitted the data. Figure 13 This is the residual analysis of the experimental data (no abnormal data). The smaller the residual is, the Figure 12 It can correctly fit the experimental data.

Claims

1. An intelligent test system for turnout switching resistance, characterized in that: The invention comprises a sample device, a test system and a calibration system, wherein the sample device is provided with an adjustment gasket (1) on the top surface of the locking iron (2), and the locking iron (2) is fixed in the locking frame by bolts, and stress pieces 1 (3) and 3 (5) are symmetrically provided on both sides of the wiring groove (7) on the top surface of the adjustment gasket (1) along the main strain direction, and stress pieces 2 (4) and 4 (6) are symmetrically provided on both sides of the wiring groove (7) along the secondary strain direction, wherein the main strain direction is the direction of the longitudinal tensile force on the locking iron (2), and the secondary strain direction is the direction of the transverse shear force, and stress pieces 5 (8), 7 (10), 6 (9) and 8 (11) are provided on the back of the adjustment gasket (1) at positions corresponding to stress pieces 1 (3), 3 (5), 2 (4) and 4 (6), respectively, and the strain pieces are electrically connected to each other through wires passing through the wiring groove (7); The calibration system includes a microcomputer-controlled electronic universal testing machine and a fixture, the microcomputer-controlled electronic universal testing machine is electrically connected to the test system, the fixture includes an upper fixture (12) and a lower fixture (13), the upper end of the upper fixture (12) is connected to the upper end of the microcomputer-controlled electronic universal testing machine through a pin shaft, the bottom of the upper fixture (12) matches the bottom of the locking iron (2), the lower end of the lower fixture (13) is connected to the lower end of the microcomputer-controlled electronic universal testing machine through a pin shaft, and the top surface of the lower fixture (13) supports the adjustment gasket (1); In the test system, the strain gauge is electrically connected to the communication module, and the communication module includes a terminal stress acquisition unit, serial port acquisition software and a host computer. The strain gauge is electrically connected to the terminal stress acquisition unit, the terminal stress acquisition unit is electrically connected to the serial port acquisition unit, and the host computer is electrically connected to the serial port acquisition unit. The terminal stress acquisition unit acquires data and transmits it to the serial port acquisition unit, and then transmits the data to the host computer for calculation and processing.

2. The intelligent test system for turnout switching resistance according to claim 1 is characterized in that: All strain gauges are connected using a full-bridge circuit.

3. The intelligent test system for turnout switching resistance according to claim 2 is characterized in that: The output end of the full-bridge circuit is connected to a high-impedance signal amplifier.

4. The intelligent test method for turnout switching resistance according to claim 3 is characterized in that: The steps include: Step 1) The stress gauges 1 (3) to 8 (11) collect the strain values generated when the switch machine is working, and use a full-bridge circuit to convert the collected strain signals into electrical signals, and the symmetrical layout of the full-bridge circuit offsets the strain drift caused by the locking iron (2) working at different temperatures outdoors; Step 2) The high-impedance signal amplifier amplifies the measured tiny signal to an electrical signal within the 5V range, and the A / D converter in the communication module converts the analog signal into a digital signal; Step 3) Apply serial communication technology, use the MAX232 chip to achieve level conversion, and then use RS-232 to USB to communicate with the PC. The microcontroller transmits the data collected by each node to the host computer through the serial port, and the data is analyzed and diagnosed; Step 4) Calibrate the collected electrical signals and the applied tension value, and establish a calibration curve based on the linear relationship between the strain gauge layout and the tension value to facilitate data analysis and processing on the host computer.

5. The intelligent test method for turnout switching resistance according to claim 4 is characterized in that: The specific process of the calibration test in step 4) is as follows: Step 4.1) Clamp both ends of the specimen assembly with fixtures and mount it on a computer-controlled electronic universal testing machine. Use a laser level to check and fine-tune the upper and lower fixtures to ensure they are completely perpendicular to the horizontal, ensuring that the axis of force applied to the sensor aligns with the axis of force applied to the press. Step 4.2) Initial value reset: After installation, there will be an initial pressure value in the test system due to preload. Use the reset button on the collector to reset the pressure value to 0. After step 4.3) preparations are complete, connect the main power supply and preheat the sample device for one hour; Step 4.4) Set the microcomputer-controlled electronic universal testing machine to zero load and ensure that the high-precision sensor built into the press is in its initial state; Step 4.5) Use the zeroing option on the data collector to reset the strain gauge output to zero, ensuring there is no locking force output. Step 4.6) Conduct a tensile test, which consists of a loading phase and an unloading phase. During the loading phase, load the load at a rate of 0.05 kN / s for each 1.5 kN load, then hold for 30 seconds until the load reaches 15 kN. Then, enter the unloading phase, unload the load at a rate of 0.05 kN / s for each 3 kN load, then hold for 30 seconds until the load reaches 0 kN. Step 4.7) After returning to zero load, hold for 1 minute, read the zero output value, and repeat step 4.6) six times; Step 4.8) Analyze the exported data. Using wavelet decomposition, the different frequency components of the data are decomposed. By retaining the detailed information of the low-frequency part and suppressing or removing the noise in the high-frequency part, the signal is denoised. Step 4.9) Select the curve with the lowest linearity among the six data curves output in step 4.7) as the research object, and compare the processed reconstructed signal graph with the output signal of the standard force sensor; Step 4.10) Take the average value of the different force holding stages and plot a two-dimensional graph of the average value of the holding stage and the pressure value of the standard force sensor at the current moment to form the characteristic curve of the locking force sensor.

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