Railway vehicle wheel tread damage detection system and method

Abstract

The application discloses a rail vehicle wheel tread damage detection system and method, and the method comprises the following steps: collecting the data of the downward displacement of a detection rod by using a displacement sensor; dividing the detection rod into N sampling sections along the length and numbering the N sampling sections; the length of the sampling section is the product of the interval time of twice collection of the sensor and the current speed of the wheel; selecting any point between adjacent displacement sensors on the detection rod as a splicing point, and calculating the serial number of the sampling section where the splicing point is located; classifying the sampling section between the splicing points before and after each displacement sensor as belonging to the displacement sensor; and splicing the effective data collected by each displacement sensor. The application divides the detection rod into several sampling sections by arranging multiple displacement sensors at the bottom of the detection rod, associates the data collected by each sensor with the sampling sections, splices the most accurate data collected by each sensor, and thus obtains a relatively accurate result.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of rail vehicle maintenance, and particularly relates to a system and method for detecting wheel tread damage of a rail vehicle. BACKGROUND

[0002] Railway train wheel tread damage can be measured by roundness, also known as ellipticity or out-of-roundness. The cause of roundness can be caused by wheel-rail friction, such as overall out-of-roundness (specific defect type such as polygon) caused by less ideal line, unreasonable curvature radius when turning, insufficient lubrication, etc.; and can also be caused by local out-of-roundness (specific defect type such as scuffing, peeling, etc.) caused by unreasonable braking system due to dynamic action between wheel and rail. It is uniformly referred to as tread damage in the patent. Since the wheel is a key component of the train, the tread damage affects the ride comfort, and the uneven wheel-rail force caused by the damage seriously affects the safety of train operation.

[0003] As shown in Figure 1 The existing contact detection method for detecting the damage of the wheel tread of the rail vehicle is generally a parallelogram displacement method, also known as a pedal detection method, which detects the damage 103 of the wheel tread 102. The principle of this method is to take the outer edge of the wheel rim as a reference, and to detect the wheel wear and tread scuffing by measuring the wheel rim sag. When the wheel 101 has damage 103 such as wear or scuffing and peeling, the partial radius of the rolling circle will decrease, and when the rolling circle contacts the rail, the top of the wheel rim will move downward relative to the rail. By detecting the displacement value of the downward movement of the top of the wheel rim through the contact detection, the equivalent condition of the current wheel tread 102 damage 103 can be obtained. As shown in the figure, the "rod" directly contacted by the downward movement of the top of the wheel rim when the wheel 101 passes through the detection device is shown, and the change amount of the radius of the wheel rolling circle is obtained by detecting the downward movement amount through the displacement sensor detection device. The purpose of detecting the wheel tread damage (polygon, out-of-roundness, peeling, scuffing, etc.) is achieved.

[0004] The wheel tread damage detection device has a certain length and has a moving structure such as bearing, gear, sleeve or pin mechanism at multiple places when detecting the downward movement, so as to meet the dynamic displacement detection purpose of stably pressing the device downward by the wheel on the rod and moving the device upward to the initial position after the wheel leaves. However, these mechanical structures necessarily have gaps, so there are phenomena such as seesaw and lever when the wheel rolls to different positions on the rod, resulting in deviation of the downward movement amount of the whole rod, so that the single-point displacement sensor cannot capture the displacement change of the whole rod and generates errors, and cannot reflect the true downward displacement in the whole contact process of the wheel and the detection rod. SUMMARY

[0005] In view of this, the present invention provides a rail vehicle wheel tread damage detection system and method, which utilizes multiple displacement sensors to eliminate displacement measurement errors caused by mechanical structure gaps, thereby improving the detection precision and accuracy of wheel pressure.

[0006] In order to solve the above technical problems, the technical solution of the present invention is to adopt a rail vehicle wheel tread damage detection system, including a detection rod horizontally arranged along the extension direction of the track and a displacement sensor for measuring the sinking distance of the detection rod, and the displacement sensors are two or more arranged along the axial direction of the detection rod.

[0007] As an improvement, the device further comprises a reset mechanism for resetting the detection rod to its initial state.

[0008] As a further improvement, the length of the detection rod is greater than the circumference of the wheel tread, or the length of a plurality of detection rods combined is greater than the circumference of the wheel tread.

[0009] As another further improvement, the displacement sensors are evenly arranged along the axial direction of the detection rod.

[0010] The present invention also provides a rail vehicle wheel tread damage detection method, which is applied to the above-mentioned rail vehicle wheel tread damage detection system, comprising:

[0011] The displacement sensor is used to collect the data of the downward displacement of the detection rod;

[0012] Let the length of the detection rod be L, and the amount of data that each displacement sensor can collect when the wheel moves from the upper rod to the lower rod be N. The detection rod is divided into N sampling segments along its length, and each of the N sampling segments is numbered. The length of each sampling segment is the product of the interval between two sensor acquisitions and the current wheel speed.

[0013] Select any point between adjacent displacement sensors on the detection rod as the splicing point, and calculate the serial number of the sampling segment where the splicing point is located;

[0014] The sampling segment between the front and rear joint points of each displacement sensor is assigned to the displacement sensor; if the displacement sensor is the first displacement sensor, the sampling segment before the rear joint point is assigned to the sensor; if the displacement sensor is the last displacement sensor, the sampling segment after the front joint point is assigned to the displacement sensor;

[0015] The valid data collected by each displacement sensor are combined; the valid data of each displacement sensor is the data with the same serial number as the sampling segment to which it belongs.

[0016] As an improvement, the N sampling segments are sequentially numbered 1 to N, and the data sequence collected by the displacement sensor is 1 to N.

[0017] As an improvement, the splicing point is located at the middle of two adjacent displacement sensors.

[0018] As an improvement, for the splicing point located at the middle of two displacement sensors, the sampling section where the splicing point is located is calculated by the formula s1 / △L+(s2-s1) / (2×△L), wherein s1 is the length position of the previous displacement sensor, s2 is the length position of the next displacement sensor, and△L is the length of the sampling section.

[0019] As an improvement, the method for calculating the serial number of the sampling section where the splicing point is located is:

[0020] The length of the sampling section is calculated by the formula△L=L / N, wherein L is the length of the detection rod, N is the number of the sampling sections, and△L is the length of the sampling section.

[0021] The length of the position where the splicing point is located is divided by the length of the sampling section, and the result is rounded to obtain the serial number of the sampling section where the splicing point is located.

[0022] As an improvement, the data selected from the sampling section where the splicing point is located is one of the data collected by the previous displacement sensor, the data collected by the next displacement sensor, and the average of the data collected by the previous and next displacement sensors.

[0023] The present application has the following advantages:

[0024] Due to the machining precision, there will be a certain gap between the components even if they are very precise, which leads to the fact that only the data collected at the contact with the wheel is relatively accurate. The present application divides the detection rod into several sampling sections by setting multiple displacement sensors at the bottom of the detection rod, associates the data collected by each sensor with the sampling sections, and finally splices the most accurate data collected by each sensor, so as to obtain a relatively accurate result. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The schematic diagram for detecting the damage of the wheel.

[0026] Figure 2 The schematic diagram for the wheel passing through the present application.

[0027] Figure 3 The flowchart of the present application.

[0028] Marked in the figure: 100 track, 101 wheel, 102 tread, 103 damage, 105 detection rod. DETAILED DESCRIPTION

[0029] In order to make the skilled in the art better understand the technical solutions of the present application, the present application will be further described in detail below in combination with specific embodiments.

[0030] The application provides a rail vehicle wheel tread damage detection system, which comprises a detection rod 105 arranged horizontally along the extension direction of a rail 100 and a displacement sensor for measuring the sinking distance of the detection rod, wherein the displacement sensor is two or more arranged along the axial direction of the detection rod 105. Figure 2 As shown in the figure, various mechanical motion structures are simplified into pivot points (solid circle points in the figure) and gaps (between the hollow circle and the solid circle point): when the gap motion is the largest, the rod is most inclined, that is, the rod sinking amount deviation of each point is the largest, at this time, only the sinking amount of the point where the wheel 101 contacts the detection rod 105 is relatively accurate, that is, the displacement sensor measurement of the wheel-rod contact point can more accurately reflect the sinking amount; when the wheel is located in the middle of the detection rod 105, the displacement motion is temporarily ended, and the force is balanced, at this time, the sinking amount of each part of the detection rod 105 is consistent, and the displacement sensor measurement of each part is relatively accurate.

[0031] Of course, in order to facilitate repeated measurement, a reset mechanism for resetting the initial state of the detection rod 105 is further included. In addition, in order to make each part of the finally spliced data more accurate, the displacement sensors are uniformly arranged along the axial direction of the detection rod, that is, the N displacement sensors are arranged to divide the detection rod into N+1 segments.

[0032] Of course, it can be predicted that in order to make the entire tread of the wheel contact the detection rod, the length of the detection rod should be greater than the circumference of the wheel tread. Of course, a plurality of detection rods in a spliced form can also be selected, and the length of the plurality of detection rods after splicing should be greater than the circumference of the wheel tread.

[0033] As shown in the figure, the application further provides a rail vehicle wheel tread damage detection method, which is applied to the above-mentioned rail vehicle wheel tread damage detection system and comprises the following steps. Figure 3 S1, collecting the data of the downward displacement of the detection rod by using the displacement sensor.

[0034]

[0035] From the beginning of the contact between the wheel and the detection rod (up rod) to the separation between the wheel and the detection rod (down rod), all sensors are constantly collecting displacement data.

[0036] S2, the length of the detection rod is L, and the amount of data that can be collected by each displacement sensor during the process from the up rod to the down rod of the wheel is N; the detection rod is divided into N sampling segments along the length, and the N sampling segments are numbered; the length of the sampling segment is the product of the interval time of twice collection of the sensor and the current speed of the wheel;

[0037] ​Suppose the length of the detection rod is one meter, and the rail vehicle travels at a speed of 1 meter per second, then the wheel needs one second from the upper rod to the lower rod. Suppose the displacement sensor can collect displacement data 100 times in one second, then the detection rod can be divided into 100 sampling segments, numbered 1-100. Similarly, each displacement sensor also samples 100 times in this second to obtain 100 displacement data, which are also numbered 1-100, so as to facilitate the correlation between the sampling segments and the displacement data.

[0038] Of course, it is also possible that the wheel does not pass through the detection rod at a constant speed. In this case, the length of the sampling segment is the product of the interval time of two sensor collections and the current speed of the wheel. According to the above example, if the train passes at a speed of 2 meters per second during the interval between two collections, then the length of this sampling segment is 2 centimeters; if the train passes at a speed of 0.5 meters per second during the interval between two collections, then the length of this sampling segment is 0.5 centimeters. Of course, in order to facilitate calculation, the wheel passes through the detection rod at a constant speed as much as possible.

[0039] Suppose two sensors are arranged in front and back, and the two sensors are located at 25 cm and 75 cm respectively. According to the foregoing theory, when the wheel is in the front 50 cm range, the displacement data collected by the displacement sensor in front is more accurate; when the wheel is in the rear 50 cm range, the displacement data collected by the displacement sensor in the rear is more accurate.

[0040] In order to make the result most accurate, the detection rod can be divided into an infinite number of sampling segments, and a displacement sensor is arranged under each sampling segment. In this way, it can be considered that each segment of the wheel tread contacting the detection rod is collected by a displacement sensor. However, this is very uneconomical, and in fact the error of the sampling segments on both sides of the sensor is small, which fully meets the needs of wheel damage detection. Only the most accurate displacement data collected by each sensor needs to be spliced to obtain a relatively accurate data sequence that meets the needs.

[0041] Therefore, in this embodiment, two displacement sensors are taken as an example to illustrate the present application, and the operation mode of more than two displacement sensors is similar, which can be similarly deduced.

[0042] S3 selects an arbitrary point between adjacent displacement sensors on the detection rod as a splicing point, and calculates the serial number of the sampling segment where the splicing point is located.

[0043] When selecting the splicing point, any point between adjacent displacement sensors can be selected as the splicing point, and preferably a point between two displacement sensors is selected.

[0044] For the split point in the middle of two displacement sensors, the split point is calculated by the formula s1 / △L+(s2-s1) / (2*△L), where s1 is the length position of the former displacement sensor, s2 is the length position of the latter displacement sensor, and △L is the length of the sampling section. For example, if the displacement sensors s1 and s2 are located at 25 cm and 75 cm of the detection rod respectively, and the length of the sampling section is 1 cm, then the serial number of the sampling section where the split point is located is 25 / 1+(75-25) / 2*1=50, i.e. the serial number of the sampling point where the split point is located is 50.

[0045] Of course, in some cases, the midpoint can not be selected as the split point, and any point between the two displacement sensors can be selected as the split point. In this case, the length of the sampling section is calculated by the formula △L=L / N, where L is the length of the detection rod, N is the number of sampling sections, and △L is the length of the sampling section. Then, the length of the position where the split point is located is divided by the length of the sampling section, and the result is rounded to obtain the serial number of the sampling section where the split point is located. For example, if 48.5 cm is selected as the split point, then 48.5 / 1=48.5, and after rounding, the serial number of the sampling section where the split point is located is 49.

[0046] S4 divides the sampling sections between the split points before and after each displacement sensor into the displacement sensor to which the sampling sections belong. If the displacement sensor is the first displacement sensor, the sampling sections before the split point behind the displacement sensor belong to the displacement sensor. If the displacement sensor is the last displacement sensor, the sampling sections after the split point in front of the displacement sensor belong to the displacement sensor.

[0047] After the split points are set, the sampling sections under the jurisdiction of each displacement sensor need to be divided. The purpose is to allocate the sampling sections to the displacement sensor that collects the most accurate data. Taking the above two sensors as an example, the sampling sections with serial numbers 1-50 are allocated to the displacement sensor s1 in front, and the sampling sections with serial numbers 51-100 are allocated to the displacement sensor s2 in back.

[0048] In the present application, the jurisdictional areas of each displacement sensor are divided by the split points. The two displacement sensors at both ends are slightly special, and the jurisdictional areas are from the end to the nearest split point.

[0049] S5 splices the effective data collected by each displacement sensor. The effective data of each displacement sensor is the data with the same serial number as the sampling section to which the displacement sensor belongs.

[0050] Similarly, taking the 1-meter long detection rod and the two displacement sensors s1 and s2 as an example, from the upper rod to the lower rod, both displacement sensors s1 and s2 collect 100 displacement data. For s1, only data 1-50 are valid data, and for s2, only data 51-100 are valid data. The valid data of the two displacement sensors are spliced to obtain the final detection value.

[0051] Sometimes, there are an odd number of sampling segments between the two displacement sensors, for example, 5. The splicing point is set in the middle, i.e., the third sampling segment. In this case, the third sampling segment can belong to the previous displacement sensor, or belong to the next displacement sensor, or the data of the third sampling segment collected by the two sensors can be averaged, which can be selected according to the actual situation.

[0052] The above is only a preferred embodiment of the present application, and it should be pointed out that the above preferred embodiment should not be regarded as a limitation of the present application, and the protection scope of the present application should be limited by the scope defined by the claims. For ordinary skilled persons in the art, several improvements and refinements can be made without departing from the spirit and scope of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A rail vehicle wheel tread damage detection system, characterized by: It includes a detection rod horizontally arranged along the extension direction of the track and a displacement sensor for measuring the sinking distance of the detection rod, wherein the displacement sensors are two or more arranged along the axial direction of the detection rod; The method for detecting rail vehicle wheel tread damage using the rail vehicle wheel tread damage detection system includes: The displacement sensor is used to collect the data of the downward displacement of the detection rod; Let the length of the detection rod be L, and the amount of data that each displacement sensor can collect when the wheel moves from the upper rod to the lower rod be N. The detection rod is divided into N sampling segments along its length, and each of the N sampling segments is numbered. The length of each sampling segment is the product of the interval between two sensor acquisitions and the current wheel speed. Select any point between adjacent displacement sensors on the detection rod as the splicing point, and calculate the serial number of the sampling segment where the splicing point is located; The sampling segment between the front and rear joint points of each displacement sensor is assigned to the displacement sensor; if the displacement sensor is the first displacement sensor, the sampling segment before the rear joint point is assigned to the sensor; if the displacement sensor is the last displacement sensor, the sampling segment after the front joint point is assigned to the displacement sensor; The valid data collected by each displacement sensor are combined; the valid data of each displacement sensor is the data with the same serial number as the sampling segment to which it belongs.

2. A rail vehicle wheel tread damage detection system according to claim 1, characterized in that: The utility model further comprises a reset mechanism for resetting the detection rod to an initial state.

3. A railway vehicle wheel tread damage detection system according to claim 1, characterized in that: The length of the detection rod is greater than the circumference of the wheel tread, or the length of a plurality of detection rods assembled together is greater than the circumference of the wheel tread.

4. A railway vehicle wheel tread damage detection system according to claim 1, characterized in that: The displacement sensors are evenly arranged along the axial direction of the detection rod.

5. The railway vehicle wheel tread damage detection system according to claim 1, characterized in that: The N sampling segments are sequentially numbered 1 to N, and the data sequence collected by the displacement sensor is 1 to N.

6. The railway vehicle wheel tread damage detection system according to claim 1, characterized in that: The joining point is located in the middle of two adjacent displacement sensors.

7. A railway vehicle wheel tread damage detection system according to claim 6, characterized in that: For the splicing point located in the middle of the two displacement sensors, the formula s1 / △L+(s2-s1) / (2×△L) is used to calculate the sampling segment where the splicing point is located, where s1 is the length position of the previous displacement sensor, s2 is the length position of the next displacement sensor, and △L is the length of the sampling segment.

8. A rail vehicle wheel tread damage detection system according to claim 1, characterized in that The method for calculating the serial number of the sampling segment where the splicing point is located is as follows: the length of the sampling segment is calculated using the formula ΔL=L / N, where L is the length of the detection rod, N is the number of sampling segments, and ΔL is the length of the sampling segment; The result of dividing the length of the position where the stitching point is located by the length of the sampling segment is calculated, and the result is rounded up to obtain the sequence number of the sampling segment where the stitching point is located.

9. The railway vehicle wheel tread damage detection system according to claim 1, characterized in that: The data selected for the sampling segment where the splicing point is located is one of the data collected by the previous displacement sensor, the data collected by the next displacement sensor, and the average value of the data collected by the previous and next displacement sensors.

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