Urban rail transit vehicle non-contact speed measuring device and method

Abstract

The invention discloses a non-contact speed measuring device and method for an urban rail transit vehicle, the device comprises a laser displacement sensor, a protruding displacement mark and a data acquisition and analysis system, the laser displacement sensor is installed on an axle box of the urban rail transit vehicle, the protruding displacement mark is installed on a wheel web, and the data acquisition and analysis system is connected with the protruding displacement mark. The laser displacement sensor can correspond to the convex displacement mark and acquire voltage signal change data based on light reflection detection; the laser displacement sensor is connected with the data acquisition and analysis system; and the data acquisition and analysis system acquires voltage signal change data acquired by the laser displacement sensor, and calculates the mileage and the speed of the urban rail transit vehicle according to the voltage signal change data and the diameter of the wheel. The device is simple in structure and convenient to install and use, the shaft end does not need to be dismantled during testing, and vehicle speed measurement and mileage accurate positioning of the urban rail transit vehicle can be completed in a non-contact mode.

Description

Technical Field

[0001] The present invention belongs to the technical field of urban rail transit, and more particularly relates to a non-contact speed measuring device and method for urban rail transit vehicles. Background Art

[0002] Currently, when conducting various tests on urban rail transit vehicles, it is usually necessary to test the vehicle's speed, then integrate it with the time to determine the mileage for positioning. However, the line involves multiple disciplines such as tracks, signals, and contact lines, and many types of tests are conducted using a variety of equipment. Although the vehicle has original speed sensors to provide speed signals, there are certain differences in data format and sampling frequency, making it difficult to use. At the same time, vehicle manufacturers and vehicle departments of transportation management units generally do not provide them to test teams for reasons of vehicle and equipment safety. Therefore, when conducting tests, various disciplines will also install speed sensors on the ends of the axles to obtain real-time vehicle speed and mileage information.

[0003] To install a speed sensor on an axle, one of the axle ends needs to be removed. However, most vehicles have all of their axle ends already occupied. A bogie's four axle ends typically include two signal, one brake, and one grounding axle ends. Most removals involve the grounding axle end, and a few cases the brake axle end. This inevitably results in system errors due to a missing grounding or braking channel, posing a safety hazard and absolutely unacceptable for operating passenger vehicles. Furthermore, while routine inspections are relatively quick, removing vehicle fasteners, especially those on the bogie and wheelset, requires complex procedures and the coordination of multiple parties.

[0004] Therefore, there is an urgent need for a simple testing device that does not require removal of the shaft end and can also meet the requirements of measuring vehicle speed and accurately positioning mileage. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides a non-contact speed measurement device and method for urban rail transit vehicles. The device can complete the speed measurement and mileage accurate positioning of urban rail transit vehicles in a non-contact manner without removing the axle end.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a non-contact speed measurement device for urban rail transit vehicles, the device comprising: a laser displacement sensor, a raised displacement mark, and a data acquisition and analysis system, wherein:

[0008] The laser displacement sensor is installed on the axle box of the urban rail transit vehicle, and the raised displacement mark is installed on the wheel web. The laser displacement sensor can correspond to the raised displacement mark and obtain voltage signal change data based on light reflection detection; the laser displacement sensor is connected to the data acquisition and analysis system; the data acquisition and analysis system collects the voltage signal change data obtained by the laser displacement sensor, and calculates the mileage and speed of the urban rail transit vehicle based on the voltage signal change data combined with the diameter of the wheel.

[0009] In a preferred embodiment, the laser displacement sensor is fixedly mounted on the axle box by fasteners or 3M adhesive.

[0010] In a preferred embodiment, the laser displacement sensor has a measuring range of 70 mm, a measuring center distance of 100 mm, and a measuring area range of 120 mm to 150 mm.

[0011] In a preferred embodiment, the raised displacement marker is a nylon plastic block with a thickness of 30 mm, and is fixed to the wheel web by fasteners or 3M adhesive.

[0012] In a preferred embodiment, the data acquisition and analysis system aligns the collected data according to the sampling time and step size and saves the data, and has the function of viewing or exporting the mileage and speed at each moment.

[0013] In a second aspect, the present invention further provides a method for non-contact speed measurement of an urban rail transit vehicle, which uses the above-mentioned non-contact speed measurement device for an urban rail transit vehicle to perform non-contact speed measurement of the urban rail transit vehicle, and the method comprises:

[0014] The voltage signal change data is obtained by using a laser displacement sensor installed on the axle box of an urban rail transit vehicle and a raised displacement mark installed on the wheel web;

[0015] The data acquisition and analysis system is used to calculate the mileage and speed of urban rail transit vehicles based on the voltage signal change data and the wheel diameter.

[0016] Compared with the prior art, the present invention provides a non-contact speed measurement device and method for urban rail transit vehicles, which has at least the following beneficial technical effects:

[0017] The device of the present invention has a simple structure and is easy to install and use. It does not need to remove the shaft end when conducting tests on urban rail transit vehicles, and can complete the speed measurement and accurate mileage positioning of urban rail transit vehicles in a non-contact manner.

[0018] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0022] Figure 1 A schematic diagram of the installation position of a non-contact speed measuring device for urban rail transit vehicles provided in an embodiment of the present invention.

[0023] Figure 2 The following is a schematic diagram of the working principle and flow of the data acquisition and analysis system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0025] In describing the present invention, it should be noted that some processes described in this specification and accompanying drawings include multiple operations that appear in a specific order. However, it should be understood that these operations may be performed in a different order than the order in which they appear, or may be performed in parallel. Furthermore, the use of various sequence numbers is for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0027] See also Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a non-contact speed measurement device for urban rail transit vehicles, the device comprising: a laser displacement sensor, a raised displacement mark and a data acquisition and analysis system, wherein:

[0028] The laser displacement sensor is installed on the axle box of the urban rail transit vehicle, and the raised displacement mark is installed on the wheel web. The laser displacement sensor can correspond to the raised displacement mark and obtain voltage signal change data based on light reflection detection; the laser displacement sensor is connected to the data acquisition and analysis system; the data acquisition and analysis system collects the voltage signal change data obtained by the laser displacement sensor, and calculates the mileage and speed of the urban rail transit vehicle based on the voltage signal change data and the wheel diameter.

[0029] The device of the present invention has a simple structure, is easy to install and use, does not need to remove the shaft end during testing, and can complete the speed measurement and mileage accurate positioning of urban rail transit vehicles in a non-contact manner.

[0030] The following is a detailed description of the specific implementation and working principle of a non-contact speed measuring device for urban rail transit vehicles of the present invention:

[0031] The non-contact speed measurement device for urban rail transit vehicles, presented in this invention, requires no axle end removal and maintains contact with the rolling wheelset. It primarily comprises a laser displacement sensor, a raised displacement marker, and a data acquisition and analysis system. The laser displacement sensor, the core component, operates based on the reflection and detection of light. The built-in receiver (photodiode or phototransistor) generates a voltage signal based on the time-varying reflection of the reflected light.

[0032] In this embodiment, the laser displacement sensor of the speed measuring device is mounted on the axle box so that it can illuminate the position of the wheel web. It can be secured with fasteners, tape, or 3M adhesive. A raised displacement mark is affixed to the corresponding position of the wheel web for triggering. The laser displacement sensor is connected to the vehicle's data acquisition and analysis system via a data cable or wirelessly. The laser displacement sensor emits an infrared laser, and the speed at which the built-in receiver receives the light signal changes, and the voltage signal output by the laser displacement sensor also changes accordingly. When the infrared laser is irradiated on an unmarked wheel web, the distance from the laser emission to the built-in receiver is longer, resulting in a larger displacement and a low voltage signal output by the sensor. When the infrared laser is irradiated on a wheel web with a raised displacement mark, the distance from the laser emission to the built-in receiver is shorter, resulting in a smaller displacement and a high voltage signal output by the sensor.

[0033] Furthermore, in this embodiment, the data acquisition and analysis system can obtain the number of rotations of the wheel axle based on the half-wave pulse signal formed by the high potential obtained from the laser displacement sensor, and then combine it with the diameter of the wheel to calculate the vehicle mileage. For the specific process, please refer to Figure 2 As shown. The average speed of one wheel rotation is calculated based on the interval between two high levels in the half-wave voltage pulse signal, combined with the wheel diameter. Typically, one axle rotation covers a distance of 2.3 to 2.5 meters, resulting in a limited mileage increment of 2.3 to 2.5 meters. While this test method provides very accurate mileage results, there are certain issues with aligning mileage data from various disciplines. Therefore, after determining the average speed during one axle rotation, the mileage increment is calculated based on the time intervals between the various disciplines' data. The speed is also the average speed during one axle rotation. For the period from the initial 0 to the first high and low levels of the first half-wave voltage pulse signal, considering the lower speed, the speed from the high and low levels of the first half-wave voltage pulse signal to the high and low levels of the second half-wave voltage pulse signal is used to calculate the mileage and speed from the initial 0 to the high and low levels of the first half-wave voltage pulse signal.

[0034] For example, if the wheel diameter is d=760mm, time 0 is the mileage position k0=0.011km (the mileage position in the line is represented by K0+011). The time when the 1st, 2nd, 3rd, 5000th and 5001st high potentials appear are t1=2.00035s, t2=6.77557s, t3=9.16318s, t4=10.16318s and t5=10.16318s, respectively. 5000 =800.01549s and t 5001 =800.10561s.

[0035] The data calculation process is:

[0036] (1) The wheel circumference M is:

[0037] M=πd

[0038] M=3.14159265*760=2387.61mm=2.38761m;

[0039] (2) The distance M2 traveled by the train from t1 to t2 is:

[0040] M2=M

[0041] M2=2.38761m;

[0042] (3) The speed v2 of the train from t1 to t2 is:

[0043] v2=M2 / (t2-t1)=M / (t2-t1)

[0044] v2=2.38761 / (6.77557-2.00035)=0.5m / s=1.8km / h;

[0045] (4) The speed v1 of the train from 0 to t1 is:

[0046] v1=v2

[0047] v1=0.5m / s=1.8km / h;

[0048] (5) The distance M1 traveled by the train from time 0 to t1 is:

[0049] M1=v1*t1

[0050] M1=0.5*2.00035=1.00018m;

[0051] (6) The train's mileage position k1 at time t1 is:

[0052] k1=k0+M1

[0053] k1=0.011*1000+1.00018=12.00018m, the line mileage position is K0+012;

[0054] (7) The train's mileage position k2 at time t2 is:

[0055] k2=k0+M1+M2=k0+M1+(2-1)*M

[0056] k2=0.011*1000+1.00018+(2-1)*2.38761=14.38779

[0057] The line mileage position is K0+014;

[0058] (8) The distance M3 traveled by the train from t2 to t3 is:

[0059] M3=M

[0060] M3=2.38761m;

[0061] (9) The speed v3 of the train from t2 to t3 is:

[0062] v3=M3 / (t3-t2)=M / (t3-t2)

[0063] v3=2.38761 / (9.16318-6.77557)=1.0m / s=3.6km / h;

[0064] (10) The train's mileage position k3 at t3 is:

[0065] k2=k0+M1+M2+M3=k0+M1+(3-1)*M

[0066] k2=0.011*1000+1.00018+(3-1)*2.38761=14.38779

[0067] The line mileage position is K0+014;

[0068] (11)t 5000 to t 5001 The distance M traveled by the train in time 5001 for:

[0069] M 5001 =M

[0070] M 5001 =2.38761m;

[0071] (12)t 5000 to t 5001 The speed of the train during time v 5001 for:

[0072] v 5001 =M 5001 / (t 5001 -t 5000 )=M / (t 5001 -t 5000 )

[0073] v 5001 =2.38761 / (800.10561-800.01549)=26.5m / s=95.4km / h;

[0074] (13)t5001 The train's mileage position k 5001 for:

[0075] k 5001 =k0+M1+M2+M3……M 5001 =k0+M1+(5001-1)*M

[0076] k 5001 =0.011*1000+1.00018+(5001-1)*2.38761=11950.05018m

[0077] The line mileage position is K11+950;

[0078] (14) With any t i For example, if t i =800.05561s The speed at this time is v i for:

[0079] Because t 5000 <t i ≤t 5001 ,so:

[0080] v i =v 5001

[0081] v i =26.5m / s=95.4km / h;

[0082] (15)t i =800.05561s The mileage position at this time is k i for:

[0083] Because t 5000 <t i ≤t 5001 ,so:

[0084] k i =k 5000 +v 5001 *(t i -t 5000 )=k 5001 -M+v 5001 *(t i -t 5000 )

[0085] k i =11950.05018-2.38761-26.49368*(800.05561-800.01549)=11946.59964m

[0086] The line mileage position is K11+947.

[0087] Therefore, although speed and mileage data are delayed by 2.3 to 2.5 meters using this algorithm, the errors in speed and mileage are minimal, especially in mileage. Furthermore, after stopping sampling and recalculating the data based on the sampling time and step size, the mileage, speed, and related data at each moment can be viewed or exported. Furthermore, the displacement of the axlebox and wheels during train operation is very limited. Because the wheels and axles are installed with an interference fit, there is almost no radial displacement, and due to installation clearance, there is only 2 to 3 mm of axial displacement. Therefore, accurate mileage and speed data for urban rail transit vehicles can be obtained.

[0088] In a preferred embodiment, the laser displacement sensor used in the present invention has a measuring range of 70mm, a measuring center distance of 100mm, and a thickness of the installation raised displacement mark of 30mm. During installation, a portion of the measuring range can be reserved on both sides of the laser displacement sensor, and the measurement area is selected to be around 120mm to 150mm. Thus, when the sensor is irradiated on the unmarked web, the displacement value is displayed as 50mm, and the voltage signal is a low-order voltage signal with a value of 1429mV; when the sensor is irradiated on the raised displacement mark, the displacement value is displayed as 20mm, and the voltage signal is a high-order voltage signal with a value of 3571mV. At this time, the speed channel of the data acquisition and analysis system can be set to a rising edge trigger mode, with one pulse per revolution. The low-order trigger voltage should be set higher than the low-order voltage signal, generally around 500mV higher and then rounded up, and can be set to 2000mV; the high-order trigger voltage should be set lower than the high-order voltage signal, generally around 500mV lower and then rounded up, and can be set to 3000mV. In the counting setting, you can set the initial mileage, increase or decrease, and the mileage corresponding to one pulse, that is, the mileage corresponding to one rotation.

[0089] In addition, during on-site installation, it is important to note that if the wheelset is using a belly brake, avoid the brake pad area during installation. Considering that the wheelset vibrates significantly during driving, especially when experiencing severe short-wave roughness, the vibration is more pronounced. Therefore, the laser displacement sensor and the raised displacement marker installed on the wheel belly should be securely installed. The sensor should preferably be installed using fasteners and the installation reliability should be checked. The raised displacement marker should preferably be made of lightweight, opaque nylon blocks or other plastic blocks, firmly attached with 3M self-adhesive tape, and checked before each race.

[0090] From the description of the above embodiments, those skilled in the art can know that the present invention provides a non-contact speed measuring device for urban rail transit vehicles. The device has a simple structure and is easy to install and use. There is no need to remove the axle end when conducting tests on urban rail transit vehicles. It can complete the speed measurement and mileage accurate positioning of urban rail transit vehicles in a non-contact manner.

[0091] Furthermore, an embodiment of the present invention also provides a method for non-contact speed measurement of an urban rail transit vehicle, which uses the above-mentioned non-contact speed measurement device for an urban rail transit vehicle to perform non-contact speed measurement of an urban rail transit vehicle. The method includes:

[0092] ① Obtain voltage signal change data through the laser displacement sensor installed on the axle box of the urban rail transit vehicle and the raised displacement mark installed on the wheel web;

[0093] ② Use the data acquisition and analysis system to calculate the mileage and speed of urban rail transit vehicles based on the voltage signal change data and the wheel diameter.

[0094] An embodiment of the present invention provides a non-contact speed measurement method for urban rail transit vehicles, the implementation principle and technical effects of which are the same as those of the aforementioned device embodiment. For the sake of brief description, for parts not mentioned in this embodiment, reference can be made to the corresponding contents in the aforementioned device embodiment, which will not be repeated here.

[0095] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0096] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A non-contact speed measuring device for urban rail transit vehicles, characterized in that: The device includes: a laser displacement sensor, a raised displacement mark and a data acquisition and analysis system, wherein: The laser displacement sensor is installed on the axle box of the urban rail transit vehicle, and the raised displacement mark is installed on the wheel web. The laser displacement sensor can correspond to the raised displacement mark and obtain voltage signal change data based on light reflection detection; the laser displacement sensor is connected to the data acquisition and analysis system; the data acquisition and analysis system collects the voltage signal change data obtained by the laser displacement sensor, and calculates the mileage and speed of the urban rail transit vehicle based on the voltage signal change data combined with the diameter of the wheel.

2. The non-contact speed measuring device for urban rail transit vehicles according to claim 1, characterized in that: The laser displacement sensor is fixedly mounted on the axle box by fasteners or 3M adhesive.

3. The non-contact speed measuring device for urban rail transit vehicles according to claim 1, characterized in that: The laser displacement sensor has a measuring range of 70 mm, a measuring center distance of 100 mm, and a measuring area range of 120 mm to 150 mm.

4. The non-contact speed measuring device for urban rail transit vehicles according to claim 1, characterized in that: The raised displacement marker is a plastic block with a thickness of 30 mm, and is fixed to the wheel belly plate by fasteners or 3M adhesive.

5. The non-contact speed measuring device for urban rail transit vehicles according to claim 1, characterized in that: The data acquisition and analysis system aligns the collected data according to the sampling time and step size and saves the data. It has the function of viewing or exporting the mileage and speed at each moment.

6. A non-contact speed measurement method for urban rail transit vehicles, characterized in that: Using a non-contact speed measuring device for an urban rail transit vehicle according to any one of claims 1 to 5, the method for performing non-contact speed measurement of an urban rail transit vehicle comprises: The voltage signal change data is obtained by using a laser displacement sensor installed on the axle box of an urban rail transit vehicle and a raised displacement mark installed on the wheel web; The data acquisition and analysis system calculates the mileage and speed of urban rail transit vehicles based on the voltage signal change data and the wheel diameter.

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