Method for fitting oil pressure curve through power curve of electro-hydraulic switch machine

Abstract

The present invention discloses a method for fitting an oil pressure curve through an electro-hydraulic switch machine power curve, comprising: step S1, detecting the actual power curve of the electro-hydraulic switch machine; step S2, fitting a fitting oil pressure curve according to the actual power curve; step S3, fitting an intermediate section of the oil pressure through secondary fitting of the actual power intermediate section; step S4, smoothly transitioning the initial value of the oil pressure to the initial value of the fitting, to obtain an initial section of the fitting oil pressure; and obtaining a first peak value of the fitting by summing the second peak value of the fitting and a fixed difference, thereby forming a final section of the fitting oil pressure. The present invention can obtain a real-time fitting oil pressure curve by converting the actual power curve. The fitting oil pressure curve thus obtained not only does not need to be measured at the turnout, but also can show real-time reaction to the dynamics of the electro-hydraulic switch machine. The fitting oil pressure curve has high precision, so that faults can be diagnosed and warned through the fitting oil pressure curve, and hidden dangers of faults can be solved in advance to prevent them before they happen.

Description

Technical Field

[0001] The invention relates to a method for fitting an oil pressure curve through a power curve of an electro-hydraulic switch machine. Background Art

[0002] Subway signal equipment is the infrastructure of urban rail transit, and is also an important basic condition for ensuring driving safety, improving passenger efficiency and improving working conditions. With the opening of Shanghai Metro Line 4 and Line 10, the switch equipment began to try to introduce rail sleeper hydraulic external locking turnouts, three-way hydraulic external locking turnouts and single-way hydraulic external locking turnouts. Since the hydraulic external locking turnouts were used for the first time in Shanghai Metro, the design problems of the hydraulic turnouts themselves and the lack of maintenance experience have caused more failures, and some of the failures are instantaneous. Due to the lack of necessary maintenance means, maintenance personnel have great difficulties in analyzing and judging the hidden dangers of the equipment, implementing the causes of the failures after the failures, and taking rectification and preventive measures.

[0003] The oil pressure of the switch machine is the most critical technical indicator of the hydraulic turnout. According to the oil pressure, the maintenance personnel can judge whether the turnout is working properly. Generally, the maintenance personnel are at the turnout during the non-operating period of the subway, connect the oil pressure gauge, operate the turnout, observe the changes in the oil pressure gauge pointer with the naked eye, and record the maximum oil pressure. This maintenance method is not only inefficient, but also unable to continuously and automatically record the entire oil pressure curve. There is still a certain error in the naked eye observation method. Therefore, it is impossible to realize the real-time monitoring of the oil pressure during the turnout switching process, and it is impossible to timely intelligently diagnose and alarm the equipment whose status has changed. As a result, it is impossible to discover the hidden dangers of faults in advance and solve the faults in the bud. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the oil pressure curve of the electro-hydraulic switch machine cannot be recorded and monitored in real time, resulting in the inability to diagnose and warn faults in advance, and to provide a method for fitting the power curve of the electro-hydraulic switch machine to the oil pressure curve.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A method for fitting an oil pressure curve through an electro-hydraulic switch machine power curve comprises the following steps:

[0007] Step S1, detecting the actual power curve of the electro-hydraulic switch machine;

[0008] Step S2, fitting a fitting oil pressure curve according to the actual power curve, the fitting oil pressure curve is divided into three sections, including a fitting oil pressure initial section, a fitting oil pressure middle section and a fitting oil pressure final section, which correspond to the actual power initial section, the actual power middle section and the actual power final section respectively;

[0009] Step S3, the fitted oil pressure intermediate segment is obtained by secondary fitting of the corresponding actual power intermediate segment, and the fitted initial value and the fitted second peak value of the fitted oil pressure intermediate segment are obtained, wherein the initial value is the value corresponding to the initial endpoint of the fitted oil pressure intermediate segment, and the fitted second peak value is the highest peak value of the fitted oil pressure intermediate segment;

[0010] Step S4, smoothly transition the initial oil pressure value to the initial fitting value to obtain the initial segment of the fitting oil pressure; obtain the first fitting peak value by summing the second fitting peak value and the fixed difference, and transition the end of the middle segment of the fitting oil pressure to the first fitting peak value, thereby forming the final segment of the fitting oil pressure.

[0011] The middle parts of the power curve and the oil pressure curve have the same trend, and there is a corresponding relationship. Therefore, we only need to obtain the conversion relationship between the actual power middle section and the fitted oil pressure middle section, and then we can fit the actual power middle section to the fitted oil pressure middle section.

[0012] For the initial stage of fitting oil pressure, according to the principle of three-phase electricity, the instantaneous power of the motor when starting is very large, and at this stage, the oil pressure slowly increases from the initial value of the oil pressure (generally 0). Therefore, in the initial stage of fitting oil pressure, the initial value of the oil pressure smoothly transitions to the initial value of fitting, thereby completing the drawing of the initial stage of fitting oil pressure.

[0013] For the final stage of the fitted oil pressure, the oil pressure reaches the maximum value by inertia in the final stage of the turnout action, and the motor power has begun to fall back at this time, that is, after the power drops rapidly, the oil pressure and power do not correspond. However, at this time, the difference between the highest value (first peak value) and the second highest value (second peak value) of the oil pressure is a basically constant fixed difference. Therefore, the first peak value can be obtained by the second peak value of the fitting that falls in the middle stage of the fitted oil pressure. The final stage of the fitted oil pressure can be obtained by the transition.

[0014] The actual power curve can be drawn by the electrical parameters obtained in real time by the sensor of the acquisition module. At this time, the real-time fitting oil pressure curve can be obtained by converting the actual power curve. The fitting oil pressure curve obtained in this way not only does not need to be measured at the turnout, but also can show the real-time reaction of the electro-hydraulic switch machine dynamics like the actual power curve. Therefore, the fault diagnosis and early warning can be carried out by fitting the oil pressure curve, and the hidden dangers of the fault can be solved in advance to prevent it before it happens.

[0015] Preferably, the fixed difference is a constant value, obtained by a test oil pressure curve obtained by testing the electro-hydraulic switch machine, wherein the fixed difference is obtained by subtracting a test second peak value from a test first peak value in the test oil pressure curve. The fixed difference obtained by the test first peak value and the test second peak value can be used to calculate the fitting first peak value, and the accuracy of the fitting can be ensured.

[0016] Preferably, the initial value of the oil pressure is 0. The initial value of the oil pressure of a common electro-hydraulic switch machine is 0, but in some cases, the initial value of the oil pressure may not be 0.

[0017] Preferably, in step S3, the fitting of the fitting oil pressure middle section is obtained by converting the actual power curve through a conversion equation, and the conversion equation is calculated by a test power curve obtained when the electro-hydraulic switch machine is tested and a corresponding test oil pressure curve.

[0018] Preferably, the test power curve includes a test power middle section, the test oil pressure curve includes a test oil pressure middle section, and the time interval of the fitted oil pressure middle section is the same as the time interval of the test oil pressure middle section.

[0019] Preferably, the calculation process of the conversion equation includes:

[0020] Step A1, setting a quadratic equation to be solved related to the power value and the oil pressure value, selecting three test power values ​​in the middle section of the test power, and finding the corresponding three test oil pressure values ​​in the middle section of the test oil pressure;

[0021] Step A2, substituting three test power values ​​and three test oil pressure values ​​into the quadratic equation to be solved;

[0022] Step A3: Solve the coefficients of the quadratic equation to be solved to obtain the conversion equation.

[0023] Preferably, the quadratic equation to be solved is aW2+bW+c=P, wherein a, b, c are coefficients, W is the power value, and P is the oil pressure value.

[0024] Preferably, when the electro-hydraulic switch machine is used in a three-way turnout, the time interval of the fitting oil pressure middle section and the test oil pressure middle section is 0.2s-5.6s.

[0025] Preferably, when the electro-hydraulic switch machine is used in a sleeper turnout, the time interval of the fitting oil pressure middle section and the testing oil pressure middle section is 0.2s-4.4s.

[0026] Preferably, when the electro-hydraulic switch machine is used for a single turnout, the time interval of the fitting oil pressure middle section and the test oil pressure middle section is 0.2s-5.2s.

[0027] The positive and progressive effect of the present invention is that the present invention can obtain a real-time fitting oil pressure curve by converting the actual power curve. The fitting oil pressure curve thus obtained not only does not need to be measured at the turnout, but can also show the real-time reaction of the electro-hydraulic switch machine dynamics like the actual power curve. The fitting oil pressure curve has high precision, so that the fault diagnosis and early warning can be carried out through the fitting oil pressure curve, and the hidden dangers of the fault can be solved in advance to prevent it before it happens. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flowchart of a method for fitting an oil pressure curve through an electro-hydraulic switch machine power curve according to a preferred embodiment of the present invention.

[0029] Figure 2 Flow chart of a method for calculating a conversion equation according to a preferred embodiment of the present invention.

[0030] Figure 3 A schematic diagram of a test power curve of a preferred embodiment of the present invention.

[0031] Figure 4 A schematic diagram of a test oil pressure curve according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0033] like Figure 1-Figure 4 As shown, this embodiment discloses a method for fitting an oil pressure curve through an electro-hydraulic switch machine power curve, such as Figure 1 As shown, the following steps are included:

[0034] Step S1, detecting the actual power curve of the electro-hydraulic switch machine;

[0035] Step S2, fitting a fitting oil pressure curve according to the actual power curve, the fitting oil pressure curve is divided into three sections, including a fitting oil pressure initial section, a fitting oil pressure middle section and a fitting oil pressure final section, which correspond to the actual power initial section, the actual power middle section and the actual power final section respectively;

[0036] Step S3, the fitted oil pressure middle section is obtained by secondary fitting of the corresponding actual power middle section, and the fitted initial value and the fitted second peak value of the fitted oil pressure middle section are obtained, wherein the initial value is the value corresponding to the initial endpoint of the fitted oil pressure middle section, and the fitted second peak value is the highest peak value of the fitted oil pressure middle section;

[0037] Step S4, smoothly transition the initial oil pressure value to the initial fitting value to obtain the initial segment of the fitting oil pressure; obtain the first fitting peak value by summing the second fitting peak value and the fixed difference, and transition the end of the middle segment of the fitting oil pressure to the first fitting peak value, thereby forming the final segment of the fitting oil pressure.

[0038] The middle parts of the power curve and the oil pressure curve have the same trend, and there is a corresponding relationship. Therefore, we only need to obtain the conversion relationship between the actual power middle section and the fitted oil pressure middle section, and then we can fit the actual power middle section to the fitted oil pressure middle section.

[0039] For the initial stage of fitting oil pressure, according to the principle of three-phase electricity, the instantaneous power of the motor when starting is very large, and at this stage, the oil pressure slowly increases from the initial value of the oil pressure (generally 0). Therefore, in the initial stage of fitting oil pressure, the initial value of the oil pressure smoothly transitions to the initial value of fitting, thereby completing the drawing of the initial stage of fitting oil pressure.

[0040] For the final stage of the fitted oil pressure, the oil pressure reaches the maximum value by inertia in the final stage of the turnout action, and the motor power has begun to fall back at this time, that is, after the power drops rapidly, the oil pressure and power do not correspond. However, at this time, the difference between the highest value (first peak value) and the second highest value (second peak value) of the oil pressure is a basically constant fixed difference. Therefore, the first peak value can be obtained by the second peak value of the fitting that falls in the middle stage of the fitted oil pressure. The final stage of the fitted oil pressure can be obtained by the transition.

[0041] The actual power curve can be drawn by the electrical parameters obtained in real time by the sensor of the acquisition module. At this time, the real-time fitting oil pressure curve can be obtained by converting the actual power curve. The fitting oil pressure curve obtained in this way not only does not need to be measured at the turnout, but also can show the real-time reaction of the electro-hydraulic switch machine dynamics like the actual power curve. Therefore, the fault diagnosis and early warning can be carried out by fitting the oil pressure curve, and the hidden dangers of the fault can be solved in advance to prevent it before it happens.

[0042] like Figure 4 As shown, the fixed difference in this embodiment is a constant value, which is obtained by the test oil pressure curve obtained by the test of the electro-hydraulic switch machine, wherein the fixed difference is obtained by subtracting the test second peak value from the test first peak value in the test oil pressure curve. The fixed difference obtained by the test first peak value and the test second peak value can be used for the calculation of the fitting first peak value, and the accuracy of the fitting can be guaranteed.

[0043] The initial value of the oil pressure of the electro-hydraulic switch machine in this embodiment is 0. The initial value of the oil pressure of a conventional electro-hydraulic switch machine is 0, but in some cases, the initial value of the oil pressure may not be 0.

[0044] In this embodiment, in step S3, the fitting of the middle section of the fitting oil pressure is obtained by converting the actual power curve through a conversion equation, and the conversion equation is calculated by the test power curve obtained when the electro-hydraulic switch machine is tested and the corresponding test oil pressure curve.

[0045] Specifically, the test power curve includes a test power middle section, the test oil pressure curve includes a test oil pressure middle section, and the time interval of the fitted oil pressure middle section is the same as the time interval of the test oil pressure middle section.

[0046] like Figure 2 As shown, the calculation process of the conversion equation of this embodiment includes:

[0047] Step A1, setting a quadratic equation to be solved related to the power value and the oil pressure value, selecting three test power values ​​in the middle section of the test power, and finding the corresponding three test oil pressure values ​​in the middle section of the test oil pressure;

[0048] Step A2, substituting three test power values ​​and three test oil pressure values ​​into the quadratic equation to be solved;

[0049] Step A3: Solve the coefficients of the quadratic equation to be solved to obtain a conversion equation.

[0050] like Figure 3 and Figure 4 As shown, in this embodiment, the quadratic equation to be solved is aW 2 +bW+c=P, where a, b, c are coefficients, W is the power value, and P is the oil pressure value. Figure 3 The test power middle section takes three values: W1, W2 and W3. Figure 4 The corresponding time points of the middle section of the test oil pressure curve of the test oil pressure are taken as three values ​​P1, P2, and P3. Thus, the following set of equations is obtained:

[0051] aW 2 +bW1+c=P1

[0052] wxya 2 +bW2+c=P2

[0053] wxya 2 +bW3+c=P3

[0054] Thus, the specific values ​​of a, b, and c are obtained, and thus the conversion equation is obtained.

[0055] In this embodiment, when the electro-hydraulic switch machine is used for a three-way turnout, the time interval of the fitting oil pressure middle section and the testing oil pressure middle section is 0.2s-5.6s.

[0056] In this embodiment, when the electro-hydraulic switch machine is used for the sleeper turnout, the time interval of the fitting oil pressure middle section and the testing oil pressure middle section is 0.2s-4.4s.

[0057] In this embodiment, when the electro-hydraulic switch machine is used for a single turnout, the time interval of the fitting oil pressure middle section and the testing oil pressure middle section is 0.2s-5.2s.

[0058] In this embodiment, an outdoor acquisition module can be used to collect and save the line voltage, phase voltage, current, frequency, phase active power, phase reactive power, total active power, total reactive power and other parameters of the three-phase electricity of the electro-hydraulic switch machine, so that the monitoring station can read the data to depict the actual power curve. In order to ensure safety, the electromagnetic isolation principle can be used for indirect measurement, and the MCU controller can be used, and the sampling frequency can be up to 40ms / time. Communication can be output using the RS485 interface, and can be directly networked. Use an oil pressure gauge to collect the test oil pressure curve of the switch machine when the turnout is in action. For example, the oil pressure gauge used has an accuracy of up to 0.1%, and the sampling frequency can be up to 5ms / time, so the actual oil pressure curve can be obtained very accurately.

[0059] The present invention has the following advantages:

[0060] (1) The present invention can reduce fault delay and improve fault resolution efficiency. It can store real-time data of various parameters, and can view the data at any time when a fault occurs. It eliminates unnecessary interference when handling the fault, saves time and improves efficiency.

[0061] (2) The present invention can dynamically monitor the important parameters of the electro-hydraulic switch machine that affects the turnout, track these parameters during operation, and issue real-time alarms on the production scheduling terminal and the workshop terminal when the state of the electro-hydraulic switch machine changes. Fault hazards are discovered in advance and resolved in the bud, transforming equipment maintenance from condition-based maintenance to preventive maintenance.

[0062] (3) The present invention has the functions of managing and distributing oil pressure data, and can play back data, which is convenient for finding fault data afterwards and for maintenance personnel to find, analyze and handle fault causes. It not only greatly shortens the fault analysis time and increases the accuracy of fault handling, but also improves maintenance efficiency, thereby saving maintenance costs.

[0063] (4) The present invention performs statistical analysis on the real-time data of the turnout machine, tracks the impact of seasonal changes on the hydraulic turnout, and makes maintenance measures suitable for the equipment, which is conducive to the accumulation of maintenance experience and improves the maintenance quality of the equipment.

[0064] (5) The method of the present invention is simple and easy to implement.

[0065] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A method for fitting an oil pressure curve through an electro-hydraulic switch machine power curve, characterized in that: The following steps are involved: Step S1, detecting the actual power curve of the electro-hydraulic switch machine; Step S2, fitting a fitting oil pressure curve according to the actual power curve, the fitting oil pressure curve is divided into three sections, including a fitting oil pressure initial section, a fitting oil pressure middle section and a fitting oil pressure final section, which correspond to the actual power initial section, the actual power middle section and the actual power final section respectively; Step S3, the fitted oil pressure intermediate segment is obtained by secondary fitting of the corresponding actual power intermediate segment, and the fitted initial value and the fitted second peak value of the fitted oil pressure intermediate segment are obtained, wherein the initial value is the value corresponding to the initial endpoint of the fitted oil pressure intermediate segment, and the fitted second peak value is the highest peak value of the fitted oil pressure intermediate segment; Step S4, smoothly transitioning the initial value of the oil pressure to the initial value of the fitting to obtain the initial segment of the fitting oil pressure; The first fitting peak value is obtained by summing the second fitting peak value and the fixed difference value, and the end of the middle section of the fitting oil pressure is transitioned to the first fitting peak value, thereby forming the final section of the fitting oil pressure.

2. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 1, characterized in that: The fixed difference is a constant value, which is obtained by a test oil pressure curve obtained by testing the electro-hydraulic switch machine, wherein the fixed difference is obtained by subtracting a test second peak value from a test first peak value in the test oil pressure curve.

3. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 1, characterized in that: The initial value of the oil pressure is 0.

4. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 1, characterized in that: In step S3, the fitting of the fitting oil pressure intermediate section is obtained by converting the actual power curve through a conversion equation, and the conversion equation is calculated by the test power curve obtained when the electro-hydraulic switch machine is tested and the corresponding test oil pressure curve.

5. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 4, characterized in that: The test power curve includes a test power middle section, the test oil pressure curve includes a test oil pressure middle section, and the time interval of the fitting oil pressure middle section is the same as the time interval of the test oil pressure middle section.

6. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 5, characterized in that: The calculation process of the conversion equation includes: Step A1, setting a quadratic equation to be solved related to the power value and the oil pressure value, selecting three test power values ​​in the middle section of the test power, and finding the corresponding three test oil pressure values ​​in the middle section of the test oil pressure; Step A2, substituting three test power values ​​and three test oil pressure values ​​into the quadratic equation to be solved; Step A3: Solve the coefficients of the quadratic equation to be solved to obtain the conversion equation.

7. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 6, characterized in that: The quadratic equation to be solved is aW 2 +bW+c=P, where a, b, c are coefficients, W is the power value, and P is the oil pressure value.

8. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 5, characterized in that: When the electro-hydraulic switch machine is used for a three-way turnout, the time interval of the fitting oil pressure middle section and the test oil pressure middle section is 0.2s-5.6s.

9. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 5, characterized in that: When the electro-hydraulic switch machine is used in a sleeper turnout, the time interval of the fitting oil pressure middle section and the testing oil pressure middle section is 0.2s-4.4s.

10. The method for fitting the oil pressure curve through the power curve of the electro-hydraulic switch machine according to claim 5, characterized in that: When the electro-hydraulic switch machine is used for a single turnout, the time interval of the fitting oil pressure middle section and the testing oil pressure middle section is 0.2s-5.2s.

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