Railway rail wear measuring instrument

Abstract

A rail wear measuring instrument, including a measuring base, the measuring base is provided with a first connecting rod through a first driving part, the first connecting rod is connected with a second connecting rod through a second driving part, the second connecting rod is connected with a side plate through a connecting plate, the second connecting rod and the side plate form a U-shaped structure, a sensor base is movably arranged in the U-shaped structure, a laser ranging sensor and a third driving part are connected on the sensor base, and the third driving part is fixed on the side plate or the second connecting rod.

Description

Technical Field

[0001] This utility model belongs to the field of rail transit management, and particularly relates to the maintenance and measurement of rails. Background Technology

[0002] Rail wear is the material loss phenomenon of railway tracks caused by wheel contact friction, mainly manifested in three forms: vertical wear is the main feature on straight sections, while side wear and wavy wear (corrugation) are significant characteristics on the outer rails of curves. Its formation is closely related to wheel-rail contact stress, track geometry parameters, train traction load, and maintenance conditions. Wear directly leads to a shortened rail life, increased maintenance costs, and decreased train running stability. Actual measurements show that when the vertical wear exceeds 10 mm or the side wear rate reaches 0.3 mm per month, the replacement procedure needs to be initiated.

[0003] Therefore, it is particularly important to regularly inspect the wear of rails. In the early days, vernier rail wear measuring rulers were commonly used, and measurements were taken manually. This resulted in a large amount of data for each individual point, a heavy workload, and low efficiency due to manual operation of the equipment.

[0004] To address this issue, some rail wear testing equipment has emerged on the market. For example, Lianjie Electromechanical's LJ-GM digital rail wear measuring ruler. This device uses a handheld handheld device with two digital measuring rulers to measure individual positions. However, during use, the accuracy is affected by handheld errors, and long-distance measuring results in significant instrument wear and a large workload for operators.

[0005] Chinese patent documents CN201820627317.1 "Rail Wear Measuring Ruler", CN201720452880.5 "A Simple Device for Measuring Rail Wear", and CN201720764391.3 "A Portable Rail Wear Measuring Device" all disclose technical solutions similar to the digital rail wear measuring ruler of LJ-GM. However, the problems of handheld error, large instrument wear, and heavy workload for personnel have not been solved.

[0006] Chinese patent document CN200620041806.6, "Portable Railway Rail Head Outline Wear Measuring Device," discloses a device comprising a positioning frame, a housing, a rotating arm, a rotary encoder, and a measuring device. The housing is mounted above the positioning frame, and the rotating arm measuring device is mounted on the housing. Its lower part is attracted to the transverse reference surface of the rail head and the vertical reference surface of the lower jaw surface via side positioning plates and lower jaw surface positioning plates. The rotating arm measuring device consists of two interconnected rotating arms and two rotary encoders. The housing contains a data acquisition card and rotary encoders, whose output shafts are connected to the rotating arms. A zero-position reference block is mounted outside the housing, containing a permanent magnet that can hold the two rotating arms in place. A roller is mounted at the end of one rotating arm. As the roller rolls along the rail head profile, the two rotary encoders output rotation angle signals. These signals are processed by the data acquisition card inside the housing and then transmitted via a transmission interface. Compared to handheld measuring rulers, this technical solution can more comprehensively reflect the wear condition of the rail profile.

[0007] However, this technical solution still relies on contact measurement, which affects the accuracy of instrument wear measurement. Furthermore, this type of equipment is relatively complex to operate in practice, requiring specialized personnel to learn how to use it and necessitating the use of external electronic equipment. The knowledge required of users is higher than that of traditional wear measuring rulers. During use, manual measurement, reading, and recording are required. For example, taking a measurement and recording every 5 meters, 200 measurements are needed for 1 km of rail, representing repetitive work with a large workload and relatively high equipment cost.

[0008] In addition to the above, existing technologies also employ non-contact measurement solutions, such as the GKY-JSL-EBJ-1 rail corrugation measuring instrument developed by Jiangxi Riyue Measurement & Control. This type of instrument offers high measurement accuracy, fast measurement speed, and high efficiency. It can achieve data visualization, synchronous data saving, and is not limited by track type. However, this equipment also suffers from drawbacks such as large size and weight, inconvenient equipment transportation, and relatively complicated assembly on and off tracks. Utility Model Content

[0009] The purpose of this utility model is to provide a rail wear measuring instrument to solve the technical problems of low measurement efficiency, inconvenience of use, and heavy weight of existing devices.

[0010] To achieve the above objectives, the specific technical solution of this utility model is as follows: A rail wear measuring instrument, characterized in that it includes a measuring base, a first connecting rod provided on the measuring base via a first driving part, a second connecting rod connected to the first connecting rod via a second driving part, the second connecting rod connected to a side plate via a connecting plate, the second connecting rod and the side plate forming a U-shaped structure, a sensor base movably provided in the U-shaped structure, a laser rangefinder and a third driving part connected on the sensor base, the third driving part being fixed on the side plate or the second connecting rod.

[0011] Furthermore, the first drive unit, the second drive unit, and the third drive unit are components of the same specification and are respectively connected to the control board in the measuring base; Specifically, the first drive unit, the second drive unit, and the third drive unit are all composed of an encoder, a brushless motor, and a speed reducer.

[0012] Furthermore, the measuring base is a rectangular box shape with mechanical clamps on both sides.

[0013] Furthermore, a clamp is provided at the end of the clamp.

[0014] Furthermore, the measuring base is provided with a support base at its bottom, and the support bases are intermittently distributed along the center line of the measuring base.

[0015] Furthermore, the first connecting rod is provided with a mounting hole and a partition joint, the partition joint connecting the mounting hole and the outside of the first connecting rod, and a fixing screw is provided on the first connecting rod, the fixing screw passing through the partition joint.

[0016] Furthermore, the first connecting rod has several slots, and the side plate has openings.

[0017] Furthermore, the main body of the clamp extends outward from the measuring base.

[0018] Furthermore, the end face of the chuck is an inclined surface.

[0019] The present invention has the following advantages: 1. Compared with traditional manual equipment, the technical solution of this application realizes automatic measurement of rail profile through control board control linkage, and judges the wear of rail by the change of profile, thereby reducing the workload of manual measurement.

[0020] 2. The technical solution of this application is a non-contact measurement of the rail, which is highly accurate; at the same time, it avoids the problems of high technical threshold and heavy weight of existing rail corrugation measuring instruments. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a structural diagram of the present invention in use; Figure 3 This is a bottom view of the structure of this utility model; Figure 4 This is a schematic diagram of the structure of the first connecting rod of this utility model; Figure 5 This is a schematic diagram of the control system of this utility model. Detailed Implementation

[0022] To better understand the purpose, structure, and function of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed account of a rail wear measuring instrument.

[0023] Example 1 like Figure 1 As shown, this utility model discloses a rail wear measuring instrument, including a measuring base 1. A first connecting rod 2 is mounted on the measuring base 1 via a first driving part 12. A second connecting rod 3 is connected to the first connecting rod 2 via a second driving part 21. The second connecting rod 3 is connected to a side plate 3 via a connecting plate. The second connecting rod 3 and the side plate 31 form a U-shaped structure. A sensor base 4 is movably mounted within the U-shaped structure. A laser rangefinder 5 and a third driving part 32 are connected to the sensor base 4. The third driving part 32 is fixed to the side plate 3. This design avoids interference between the movement trajectories of the third driving part 32 and the second driving part 21.

[0024] Example 2 In this embodiment, the third drive unit 32 is fixed to the second connecting rod 3, and the side plate 3 is no longer connected to the second connecting rod 3 via a connecting plate. Compared to Embodiment 1, the technical solution of this embodiment has a simpler structure and a smaller moment of inertia at the measuring end.

[0025] Example 3 like Figure 2 As shown, in this embodiment, the first drive unit 12, the second drive unit 21 and the third drive unit 32 are components of the same specification, and are respectively connected to the control board 11 in the measuring base 1 through connecting lines, and the control board 11 controls the movement trajectory of the laser rangefinder 5.

[0026] During operation, the distance between the end of the laser rangefinder 5 and the rail 0 remains constant. Therefore, after running around the rail 0 once, the top profile of the rail 0 can be further obtained through the data from the first drive unit 12, the second drive unit 21 and the third drive unit 32. By comparing the differences in the top profile of the rail 0, it is convenient to judge the degree of wear of the rail 0.

[0027] Specifically, the laser rangefinder sensor 5 can be an LG100-110 or LGS-1012P, or a non-contact sensor of model IR18.D10L-F60.GP1I.7BF, which can eliminate the influence of stones and soil on measurement accuracy.

[0028] Specifically, the first drive unit 12, the second drive unit 21, and the third drive unit 32 are all composed of an encoder, a brushless motor, and a reducer. The brushless motor can be an S57BL95-230 DC brushless motor, and the reducer can be a Bohang N20 miniature reducer.

[0029] Specifically, the control board 11 includes a microcontroller unit (MCU), a gate driver chip, a power switch unit, a current sampling circuit, a position detection unit, and a power management module.

[0030] Specifically: Microcontroller unit (MCU): The preferred model is STM32F405 as the core processing unit, used to run the field-oriented control (FOC) algorithm and generate pulse width modulation (PWM) signals.

[0031] Gate driver chip: The preferred model is DRV8301 (or others such as IR2101S, AMT49700, etc.). This chip is used to receive pulse width modulation (PWM) signals generated by the microcontroller unit (MCU), and to perform level conversion and amplification to drive the subsequent MOS bridge circuit.

[0032] MOS transistor bridge circuit: This is basic common knowledge in the field of circuits. For example, there is the "Knowledge Points of MOS Transistor H-Bridge Drive Circuit" published by CSDN, and the "MOS Transistor H-Bridge Motor Drive Circuit and Design Schematic - KIA MOS Transistor" published by Guangdong Keyia Semiconductor Technology Co., Ltd.

[0033] Power switching unit: Consists of a three-phase full-bridge circuit, with each phase arm consisting of two MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), preferably the IRFS7530 (or others such as AOT290L, CSD18540Q5B, etc.). This unit is directly connected to the three-phase windings (U, V, W) of the motor, with each phase arm connected to a set of motors. It provides drive current to the motors by turning them on or off according to the drive signal.

[0034] Specifically, the circuit structure of the three-phase full-bridge circuit is existing technology and will not be elaborated here. For example, see the article "Principle and Circuit Diagram of Three-Phase Bridge Fully Controlled Rectifier Circuit" published on CSDN.

[0035] Current sampling circuit: It uses a combination of sampling resistors and operational amplifiers to detect the motor phase current or DC bus current in real time and feeds the analog signal back to the MCU's ADC (analog-to-digital converter) interface.

[0036] Specifically, the circuit structure of the current sampling circuit is existing technology and will not be elaborated here. For example, see the article "Voltage and Current Sampling Circuit Design and Amplification Calculation" published on CSDN.

[0037] Position detection unit: An absolute encoder (or incremental encoder, such as AS5048A, TLE5012B, etc.) installed at the rear of the motor is used to detect the rotor angle and speed information of the motor in real time, and transmit the data to the microcontroller unit (MCU) through SPI, I2C or ABZ interface.

[0038] Power management module: Provides stable and isolated power to the microcontroller unit (MCU), gate driver chip and MOS bridge circuit.

[0039] Specifically, the power management module can choose the VICOR modular power solution, which connects to an external power source via a power cord to power the device.

[0040] The microcontroller unit (MCU) is electrically connected to the gate driver chip, the gate driver chip is electrically connected to the MOS bridge circuit, the MOS bridge circuit is electrically connected to the power switch unit, the power switch unit is electrically connected to the brushless motor, the brushless motor is connected to the encoder, and the encoder is connected to the microcontroller unit (MCU), forming a closed-loop control system.

[0041] During use, the microcontroller unit (MCU) drives the brushless motor through field-oriented control (FOC), specifically including the following steps: Step 1: System Initialization and Parameter Configuration After the microcontroller unit (MCU) is powered on, it initializes its internal functional modules, including: Configure a timer (TIM) to generate six complementary PWM signals.

[0042] Configure the ADC channel for sampling phase current.

[0043] Configure a communication interface (such as SPI or I2C) to read encoder data.

[0044] Configure the registers of the driver chip (such as DRV8301) and set its operating mode, dead time, gain and other parameters. You can refer to the DRV8301 user manual for setting parameters.

[0045] Initialize the variables required for the FOC algorithm, such as the initial values ​​of the PI controller parameters, Clarke transform, and Park transform.

[0046] Step 2: Real-time Data Acquisition The MCU performs the following data acquisition operations in a loop: 1. Position / Speed ​​Detection: The absolute angle value θ of the encoder (e.g., AS5048A) is read in real time via an encoder interface (e.g., SPI). The real-time mechanical speed ω of the motor is obtained by differentiating the angle value or by directly reading the speed value provided by the encoder.

[0047] 2. Current Sampling: Two-phase currents (e.g., Iu and Iv) are sampled synchronously using the ADC module. The third-phase current Iw is calculated using Kirchhoff's law (Iu + Iv + Iw = 0).

[0048] Step 3: Magnetic Field Orientation Control (FOC) Calculation Based on the acquired data, the MCU executes the FOC algorithm, as follows: 1. Clarke Transform: Converts the acquired phase currents (Iu, Iv, Iw) in a three-phase stationary coordinate system into currents (Iα, Iβ) in a two-phase stationary coordinate system.

[0049]

[0050] 2. Park Transform: Using the electrical angle θ_e obtained from the encoder (electrical angle = number of pole pairs * mechanical angle θ), the current in the two-phase stationary coordinate system (α, β) is transformed into the two-phase rotating coordinate system (d, q), resulting in the direct-axis current Id and the quadrature-axis current Iq. Id is used to control the magnetic field strength, and Iq is used to control the torque.

[0051]

[0052] 3. PI closed-loop control: 3.1 Input the difference between the target quadrature axis current Iq_ref (related to the target torque) and the measured Iq into the q-axis PI controller, and output the voltage component Vq used to control the torque.

[0053] 3.2 Input the difference between the target direct-axis current Id_ref (usually set to 0 to achieve maximum torque-current ratio control) and the measured Id into the d-axis PI controller, and output the voltage component Vd used to control the magnetic field.

[0054] 4. Inverse Park Transform: Transforms the control voltage (Vd, Vq) in the rotating coordinate system back to the two-phase stationary coordinate system (α, β).

[0055]

[0056] 5. Space Vector Pulse Width Modulation (SVPWM): Using (Vα, Vβ) as input, the SVPWM algorithm calculates the required switching time and state of the six MOSFETs in the three-phase full-bridge circuit and generates the corresponding six PWM signals.

[0057] Step 4: Power Drive and Execution 1. The MCU outputs the generated six PWM signals to the gate driver chip (such as DRV8301).

[0058] 2. The driver chip amplifies the low-voltage PWM logic signal to generate a high-voltage, high-current signal sufficient to drive the gate of the MOSFET. Simultaneously, the dead-time control function integrated within the driver chip prevents shoot-through of the MOSFETs in the upper and lower bridge arms, protecting the power circuit.

[0059] 3. The amplified drive signal controls the turn-on and turn-off timing of each MOS transistor (such as IRFS7530) in the three-phase full-bridge circuit, thereby generating a three-phase sinusoidal current following the SVPWM law on the three-phase windings of the motor, driving the motor to rotate smoothly and efficiently.

[0060] Step 5: Closed-loop feedback and dynamic adjustment The encoder continuously feeds back new rotor position information to the MCU, and the current sampling circuit continuously feeds back new current information.

[0061] Based on this real-time feedback data, the MCU repeats steps two through four to form a high-speed, dynamic closed-loop control circuit, continuously correcting the output so that the actual torque and speed of the motor can quickly and accurately track the target value, thereby achieving high-precision motion control.

[0062] Specifically, the calculation method for the coordinates (X, Y) of the laser rangefinder sensor 5 is as follows: 1. The length of the first member 2 is L1, and one end is fixed at the origin (0,0), with an angle a1 between it and the x-axis.

[0063] 2. The second member 3 has a length of L2, and one end is fixed to the end of the first member 2, forming an angle a2 with the first member 2.

[0064] 3. The laser rangefinder 5 is fixed at the end of the second rod 3, forming an angle a3 with the second rod 3. The distance measured by the laser rangefinder 5 is LX.

[0065] Therefore, the coordinate expression of the end point (X,Y) measured by the laser rangefinder 5 is as follows: Finally, the coordinates are summarized to obtain the measured outline graphic.

[0066] Example 4 In this embodiment, the measuring base 1 is a rectangular box shape with clamps 13 on both sides. The main body of the clamps 13 extends outward from the measuring base 1. The outward expansion structure avoids contact between the middle of the clamps 13 and the track 0, thus ensuring measurement accuracy.

[0067] Specifically, the end of the clamp 13 is provided with a clamp 131. The bottom of the measuring base 1 is provided with a support 132, which is intermittently distributed on the center line of the measuring base 1. This can prevent unevenness on the surface of the rail 0 from causing warping and instability if there is a large area of ​​contact.

[0068] like Figure 2 As shown, during use, the measuring base 1 is placed on the rail 0, and the clamp 131 contacts both sides of the rail 0. During train operation, the sides and bottom of the rail 0 are not the working wear surfaces, therefore the dimensions will not change. Wear mainly occurs on the top and inner side of the top of the rail 0, such as... Figure 2 The position indicated by the wear line 01.

[0069] Therefore, both sides and the bottom of the rail 0 can be used as reference surfaces for wear measurement, and the clamping position of the chuck 131 is located 16mm below the rail surface. The end face of the chuck 131 is an inclined surface, and the end faces of the chuck 131 on both sides of the measuring base 1 form an A-shaped opening, which raises the contact surface with both sides of the rail 0, making it easier to clamp with the rail 0.

[0070] After the measuring base 1 is placed, the chuck 131 keeps the measuring base 1 stable.

[0071] Example 5 The first connecting rod 2 is provided with a mounting hole 23 and a partition 24. The partition 24 connects the mounting hole 23 and the outside of the first connecting rod 2. The first connecting rod 2 is provided with a fixing screw 25, which passes through the partition 24.

[0072] Specifically, the first connecting rod 2 is provided with several slots 22, and the side plate 31 is provided with openings, which can further reduce the structural weight of the first connecting rod 2 and the side plate 31 and reduce the moment of inertia.

[0073] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A rail wear measuring instrument, characterized in that, The device includes a measuring base (1), on which a first connecting rod (2) is provided via a first driving part (12), and a second connecting rod (3) is connected to the first connecting rod (2) via a second driving part (21). The second connecting rod (3) is connected to a side plate (31) via a connecting plate. The second connecting rod (3) and the side plate (31) form a U-shaped structure. A sensor base (4) is movably provided in the U-shaped structure. A laser ranging sensor (5) and a third driving part (32) are connected to the sensor base (4). The third driving part (32) is fixed on the side plate (31) or the second connecting rod (3).

2. The rail wear measuring instrument according to claim 1, characterized in that, The first drive unit (12), the second drive unit (21) and the third drive unit (32) are components of the same specification and are respectively connected to the control board (11) in the measuring base (1); Specifically, the first drive unit (12), the second drive unit (21), and the third drive unit (32) are all composed of an encoder, a brushless motor, and a reducer.

3. The rail wear measuring instrument according to claim 2, characterized in that, The measuring base (1) is a rectangular box shape with clamps (13) on both sides.

4. The rail wear measuring instrument according to claim 3, characterized in that, The end of the clamp (13) is provided with a chuck (131).

5. The rail wear measuring instrument according to claim 4, characterized in that, The measuring base (1) is provided with a support seat (132) at the bottom, and the support seats (132) are intermittently distributed on the center line of the measuring base (1).

6. The rail wear measuring instrument according to claim 5, characterized in that, The first connecting rod (2) is provided with a mounting hole (23) and a partition (24). The partition (24) connects the mounting hole (23) and the outside of the first connecting rod (2). The first connecting rod (2) is provided with a fixing screw (25) that passes through the partition (24).

7. The rail wear measuring instrument according to claim 6, characterized in that, The first connecting rod (2) has several slots (22), and the side plate (31) has openings.

8. The rail wear measuring instrument according to claim 7, characterized in that, The main body of the clamp (13) extends outward from the measuring base (1).

9. The rail wear measuring instrument according to claim 7, characterized in that, The end face of the chuck (131) is an inclined surface.

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