Method and device for determining the motion state of a railway vehicle wheel

Abstract

This invention relates to a method for determining the motion state of a wheel (RD) of a rail vehicle (SFZ) relative to a track (SCH) traveled by the wheel (RD) of the rail vehicle (SFZ). Successive images of the wheel-track region are recorded by a camera (KAM) focused on the wheel-track region on the rail vehicle (SFZ), wherein the wheel-track region includes at least one sub-region (RDLF) of the wheel (RD) of the rail vehicle (SFZ) and at least one sub-region (SK) of the track (SCH) to be traveled by the wheel (RD). A region is defined in the image (GER) along which the wheel (RD) and the sub-region (RDLF, SK) of the track (SCH) are in contact. In a first image, feature points (P1SK, P1RDLF) are defined with respect to the sub-region (SK) of the track (SCH) and the sub-region (RDLF) of the wheel (RD), which can be optically clearly re-identified in the first image and subsequent images. For successive images, determine the corresponding distances (D1SK, D1RDLF) from feature points (P1SK, P1RDLF) to the contact area (GER). The motion state of the wheel (RD) is determined by the changes in the distances (D1SK, D1RDLF) from feature points (P1SK, P1RDLF) to the contact area (GER) obtained from successive images.

Description

[0001] The present invention relates to a method for determining the motion state of the wheels of a rail vehicle relative to the track on which the wheels of the rail vehicle travel.

[0002] In railway technology, the term "slewing" is technically understood as the spinning and slipping of a wheel or driven wheel on the track. Therefore, during slewing, the circumferential speed of the wheel is much greater than the relative travel speed of the rail vehicle.

[0003] During idling, the friction ratio between the driven wheel and the track is too low, causing the driven wheel to slip to some extent, especially due to increased material removal, which can damage the track.

[0004] Rail vehicles are equipped with a so-called slip protection device, which prevents slippage by briefly reducing traction when the rail vehicle starts, thus ensuring optimal traction transmission from the rail vehicle's drive unit to the track.

[0005] The term "slippage" should be understood as the non-rotational sliding of a wheel or braked wheel on the track. Therefore, in slippage, the circumferential speed of the wheel is much lower than the relevant travel speed of the rail vehicle.

[0006] During sliding, the coefficient of friction between the brakes acting on the wheels becomes too high, causing the braked wheels to lock up, and damage to the track is caused, especially due to increased material removal.

[0007] Rail vehicles are equipped with a so-called slip protection device, which prevents slippage by briefly reducing braking force when the rail vehicle brakes, in order to ensure optimal transmission of braking force from the rail vehicle's braking system to the track.

[0008] The term “rolling” is understood as the “normal” rotational motion of a wheel, where the circumferential speed of the wheel during operation, start-up, and even braking is at least approximately equivalent to the corresponding travel speed of the rail vehicle.

[0009] In summary, idling, sliding, and rolling constitute the three motion states of a rail vehicle wheel.

[0010] Different systems for slip protection, or wheel slip protection, are known, based on the measurement of different physical quantities and using sensors for this purpose. For example, the angular velocity of the wheel is determined by a speed generator, or the torque of the drive unit is determined by the measured variables of a relevant current / voltage converter.

[0011] Due to the aforementioned measurement methods, these systems are typically too slow and therefore react too late to problems that arise during driving or braking.

[0012] Therefore, the technical problem to be solved by the present invention is to provide a better method for determining the motion state of rail vehicle wheels, which can achieve rapid and reliable determination of the operating state with low additional costs.

[0013] This technical problem is solved by the features of the independent claim. Advantageous improvements are given in the dependent claims.

[0014] The method of the present invention is based on a camera and uses known image processing methods or image processing algorithms.

[0015] In the method according to the invention for determining the motion state of a wheel of a rail vehicle relative to a track traveled by the wheel of the rail vehicle, successive images of the wheel-track region are recorded by a camera focused on the wheel-track region on the rail vehicle. The wheel-track region includes at least one sub-region of the wheel of the rail vehicle and at least one sub-region of the track to be traveled by the wheel.

[0016] Define a region in the image, along which the sub-regions of the wheel and track contact.

[0017] In the first image, at least one feature point is determined in or within a sub-region of the orbit, which can be clearly re-identified optically or visually in both the first and subsequent images. This point can be assigned as a component to the sub-region of the orbit.

[0018] Accordingly, in the first image, at least one feature point is determined in or within a sub-region of the wheel, which can be clearly re-identified optically or visually in the first image and subsequent images. This point can be assigned as a component to the sub-region of the wheel.

[0019] For successive images, determine the corresponding distances from feature points to the contact area. The motion state of the wheel is determined by the changes in the distances from feature points to the contact area obtained from the successive images.

[0020] In a favorable improved design, a straight line is defined as the area along which the sub-areas of the wheel and track contact.

[0021] In a favorable improved design, the track head is captured by the camera as a sub-region of the track and / or the wheel working surface is captured by the camera as a sub-region of the wheel.

[0022] In advantageous improved designs, a high-resolution camera system is used as a camera and / or a system that operates in the infrared or ultraviolet light range is used as a camera.

[0023] In a favorable improved design, the motion state of the wheel is determined as rolling, sliding, or spinning.

[0024] If the distance between the feature points of the contact area and the sub-region of the track, and the distance between the feature points of the contact area and the sub-region of the wheel are uniform and change in the same direction, then "rolling" is determined as the motion state of the wheel.

[0025] When the distance between the feature points of the contact area and the sub-region of the wheel changes, while the distance between the feature points of the contact area and the sub-region of the track remains basically unchanged, "idling" is determined as the motion state of the wheel.

[0026] When the distance between feature points in the contact area and the sub-region of the track changes, while the distance between feature points in the contact area and the sub-region of the wheel remains essentially constant, "sliding" is determined as the motion state of the wheel.

[0027] In the advantageous improved design, multiple feature points are used in the sub-regions of the track and the wheel to refine the analysis of the motion state by the corresponding distance changes to the contact area and to make corresponding fine-matching adjustments on the rail vehicle for idling or slippage.

[0028] In a favorable improved design, information about the determined operating type is transmitted to the drive control unit and / or braking control unit of the rail vehicle so that the corresponding adjustments can be initiated on the rail vehicle.

[0029] In a favorable improved design, when slippage is detected, the traction force on the rail vehicle is reduced via the rail vehicle's drive control device to at least suppress slippage. Correspondingly, when slippage is detected, the braking force on the rail vehicle is reduced via the rail vehicle's braking control device to at least suppress slippage.

[0030] In a favorable improved design, camera images are used to monitor and / or assess the track condition of a line segment (or railway section).

[0031] In advantageous design improvements, damage, surface variations, surface discoloration, and / or structures on the track or wheel sub-area are used as feature points.

[0032] In advantageous improved designs, markers are used as feature points, which are placed on sub-regions of the track or wheels.

[0033] The method according to the invention enables very fast, reliable and accurate determination of the idle and slippage of the driven wheel or brake wheel.

[0034] The method according to the invention achieves reduced or complete avoidance of wear on wheels, specifically on the working surface of the wheels, and on rails, specifically on the railhead.

[0035] The method according to the invention improves or optimizes the drive control or braking control applied to a rail vehicle during operation.

[0036] The method according to the invention enables visualization and evaluation of the current or even subsequent state of wheel motion along a track or line segment, as well as evaluation of the line state.

[0037] The method according to the invention saves on the working components required to date, such as sand or compressed air for auxiliary starting devices of rail vehicles. This also supports or enables the environmentally friendly operation of rail vehicles.

[0038] The method according to the invention is unaffected by daytime and can be used reliably even in adverse weather conditions.

[0039] This is achieved, for example, by appropriately selecting the camera system used (such as its resolution) and the wavelength range (infrared light, ultraviolet light) used for observation when the camera system is operating.

[0040] The method according to the invention extends the maintenance interval for wheel disc reshaping. It also reduces facility wear, especially in stations and on track slopes.

[0041] The invention will now be further described with reference to the accompanying drawings. Here,

[0042] Figure 1 An overview of the working principle of the invention according to the present invention is shown.

[0043] Figure 2 Reference Figure 1 The diagram illustrates the contour extraction used to determine a straight line.

[0044] Figure 3 Reference Figure 1 and Figure 2 This demonstrates the determination of feature points.

[0045] Figure 4 Reference Figure 3 This shows the distance from the defined feature point to the line.

[0046] Figure 5 Referring to the preceding figures, a flowchart of the method according to the present invention is shown.

[0047] Figure 6 A schematic diagram illustrating the use of camera images within the scope of this invention is provided.

[0048] Figure 7A rail vehicle equipped with a camera device is shown relative to the method according to the invention.

[0049] Figure 1 An overview of the working principle of the invention according to the present invention is shown.

[0050] The rail vehicle is equipped with a camera, preferably a high-resolution camera, which is aimed at or focused on the wheel-track area.

[0051] Within this area, at least one sub-region of the wheel RD of the rail vehicle and at least one sub-region of the track SCH to be traveled by the wheel are visible.

[0052] Preferably, the camera detects the wheel working surface RDLF as a sub-region of the wheel RD in successive images, and the rail head SCHK as a sub-region of the rail SCH.

[0053] Using the camera or evaluation electronics, a straight line GER is determined between the track head SCHK and the wheel working face RDLF in successive images from the camera, along which the two contact.

[0054] In successive images from the camera, feature point P1SK is determined on the track head SCHK using evaluation electronics. Correspondingly, feature point P1RDLF is determined on the wheel working surface RDLF.

[0055] Optically identifiable and clearly assignable points are used as feature points P1SK and P1RDLF. Examples include identifiable damage, surface changes, and surface discoloration on the rail head SCHK or wheel working surface RDLF.

[0056] Alternatively or as a supplement, specially designed markings may be used as feature points, which are placed on the railhead SCHK and / or wheel working face RDLF.

[0057] In successive images from the camera, the distance D1SK between the feature point P1SK and the line GER is determined using evaluation electronics.

[0058] Accordingly, the distance D1RDLF is determined between the feature point P1RDLF and the line GER.

[0059] These distances D1SK and D1RDLF vary depending on the motion state of the RD wheels of the rail vehicle.

[0060] During the wheel movement along the FRTR direction of travel,

[0061] - During rolling, the two distances D1SK and D1RDLF decrease uniformly.

[0062] - During idling (i.e., when wheel RD slips), the distance D1RDLF decreases, while the distance D1SK remains essentially unchanged, and

[0063] - During slippage (i.e. when wheel RD is locked), the distance D1RDLF remains essentially unchanged, while the distance D1SK decreases.

[0064] The motion state of the wheels RD of a rail vehicle can be inferred or determined by analyzing successive images.

[0065] The aforementioned checks and assessments of distance changes are conducted within the specified tolerance range. Therefore, minor deviations in distance changes that occur during the operation of rail vehicles do not lead to distortion of the assessment results.

[0066] Figure 2 Reference Figure 1 The profile extraction is shown, and the result is the straight line GER between the wheel working face RDLF and the rail head SK.

[0067] Figure 3 Reference Figure 1 , Figure 2 The diagram shows the feature points P1SK, P2SK, P3SK, P1RDLF, P2RDLF, and P3RDLF that were identified or extracted.

[0068] Figure 4 Reference Figure 3 The distances D1SK, D2SK, D3SK, D1RDLF, D2RDLF, and D3RDLF relative to the line GER are shown for the feature points P1SK, P2SK, P3SK and P1RDLF, P2RDLF, P3RDLF.

[0069] Through Figure 3 and Figure 4 The analysis shown uses multiple feature points and / or correlation analysis of corresponding distance changes to refine the analysis of motion state and determine more accurate results regarding the degree of idling or slippage.

[0070] This enables precise matching and adjustment to reduce or completely avoid idling or slippage.

[0071] Figure 5 The method according to the invention is illustrated in the preceding figures as a flowchart or according to the corresponding software architecture.

[0072] In the first program block B1, successive camera images are generated using a high-resolution camera, in which the wheel-track area can be seen.

[0073] These images are preprocessed in the second program block B2 and classified in the third program block B3, i.e., assigned to the corresponding monitored wheels of the rail vehicle.

[0074] In the fourth program block B4, contour extraction is performed to determine the straight line along which the wheel (wheel working surface) and the track (track head) contact.

[0075] Extract or determine one or more feature points on the wheel or the working surface of the wheel in the fifth program block B5.

[0076] In the sixth program block B6, determine the distance from the feature point of the wheel or the working surface of the wheel to the straight line.

[0077] Extract or determine one or more feature points on the track or track head in the seventh program block B7.

[0078] In the eighth program block B8, determine the distance from the feature point of the track or track head to the straight line.

[0079] In the ninth program block B9, determine the change in distance from the corresponding feature point to the straight line and infer the running type of the wheel.

[0080] In the tenth program block B10, information about the determined operating type is supplied to the drive control unit and / or the braking control unit of the rail vehicle.

[0081] If wheel slippage is detected, the traction force on the rail vehicle is reduced for a limited time via the drive control device to reduce or prevent slippage.

[0082] If wheel slippage is detected, a time-limited reduction in braking force is initiated on the rail vehicle via the braking control device to reduce or prevent slippage.

[0083] Figure 6 A schematic diagram illustrating the use of camera images within the scope of this invention is shown.

[0084] The high-resolution images generated by the camera KAM are input into the image processing program BVP, where they are analyzed and the type of wheel operation is determined.

[0085] In the preferred improved design, the orbital state is determined or detected by the image processing program BVP.

[0086] Camera images, operation type and / or track status information are preferably transmitted to the ground-side control center LS or communication platform KOM, such as the RAILIGENT platform, for further processing.

[0087] In the preferred improved design, camera images, operation type and / or track status information are transmitted to the central train control equipment ZSG of the rail vehicle.

[0088] The central train control equipment ZSG, in its preferred improved design, utilizes a remote data transmission device for rail vehicles. The radio-controlled relay is initiated for further processing.

[0089] In a preferred improved design, the central train control equipment ZSG initiates its recording via the rail vehicle's memory SP.

[0090] In a preferred improved design, the central train control equipment ZSG activates the aforementioned corresponding measures via the drive control device ASG or the brake control device BSG to overcome slippage or drift.

[0091] In a preferred improved design, the central train control equipment ZSG provides information to the locomotive driver of the rail vehicle via a display unit HMI.

[0092] This information preferably relates to the determined operating type of the wheels and / or the appropriate corresponding measures that the locomotive driver should take.

[0093] In a preferred improved design, this information includes messages about automatically taken and executed corresponding measures in order to notify the locomotive driver of the driving or braking situation.

[0094] Figure 7 The advantageous layout of the rail vehicle SFZ and the camera KAM used in the method according to the invention is shown in the figure, with a single camera arranged on each individual wheel RD.

Claims

1. A method for determining the motion state of a wheel (RD) of a rail vehicle (SFZ) relative to a track (SCH) traveled by the wheel (RD) of the rail vehicle (SFZ), in, Successive images of the wheel-track region are recorded by a camera (KAM) focused on the wheel-track region on a rail vehicle (SFZ), wherein the wheel-track region includes at least one sub-region (RDLF) of the wheel (RD) of the rail vehicle (SFZ) and at least one sub-region (SK) of the track (SCH) to be traveled by the wheel (RD). In the image, a contact area (GER) is defined, and sub-regions (RDLF, SK) of the wheel (RD) and track (SCH) contact along the contact area. In the first image, at least one feature point (P1SK) is determined in relation to a sub-region (SK) of the orbit (SCH), which can be optically recognizable in both the first and subsequent images. In the first image, at least one feature point (P1RDLF) is determined in relation to a sub-region (RDLF) of the wheel (RD), which can be optically clearly re-identified in the first image and subsequent images. Specifically, for successive images, the distance (D1SK) from the feature point (P1SK) of the sub-region (SK) of the track (SCH) to the contact area (GER) and the distance (D1RDLF) from the feature point (P1RDLF) of the sub-region (RD) of the wheel (RD) to the contact area (GER) are determined respectively. Specifically, the motion state of the wheel is determined by the relative relationship between the change in the distance (D1SK) from the feature point (P1SK) of the sub-region (SK) of the track (SCH) obtained from successive images to the distance (D1RDLF) from the feature point (P1RDLF) of the sub-region (RDLF) of the wheel (RD) to the contact area (GER) obtained from successive images, and the change in the distance (D1RDLF) from the feature point (P1RDLF) of the sub-region (RDLF) of the wheel (RD) obtained from successive images. Where the distance (D1SK) between the feature point (P1SK) of the contact area (GER) and the sub-region (SK) of the track (SCH) and the distance (D1RDLF) between the feature point (P1RDLF) of the contact area (GER) and the sub-region (RDLF) of the wheel (RD) vary uniformly and in the same direction, rolling is defined as the motion state of the wheel (RD). Where the distance (D1RDLF) between the contact area (GER) and the feature point (P1RDLF) of the wheel's sub-region (RDLF) changes, while the distance (D1SK) between the contact area (GER) and the feature point (P1SK) of the track's sub-region (SK) remains substantially unchanged, idling is defined as the motion state of the wheel (RD). When the distance (D1SK) between the contact area (GER) and the feature point (P1SK) of the sub-region (SK) of the track (SCH) changes, while the distance (D1RDLF) between the contact area (GER) and the feature point (P1RDLF) of the sub-region (RDLF) of the wheel (RD) remains essentially unchanged, sliding is determined as the motion state of the wheel (RD).

2. The method according to claim 1, wherein, The straight line (GER) is defined as the region (GER), and the sub-regions (RDLF, SK) of the wheel (RD) and track (SCH) are in contact along this straight line.

3. The method according to claim 1 or 2, in, The track head (SK) of the track is captured by the camera (KAM) as a sub-region of the track (SCH), and / or The working surface (RDLF) of the wheel is captured by the camera (KAM) as a sub-region of the wheel (RD).

4. The method according to claim 1, in, As a camera (KAM), a high-resolution camera system is used, and / or Among them, the camera (KAM) is used in systems that operate in the infrared or ultraviolet light range.

5. The method according to any one of the preceding claims, wherein, Multiple feature points (P1SK, P2SK, P3SK, P1RDLF, P2RDLF, P3RDLF) are used in the sub-regions (SK) of the track (SCH) and the sub-regions (RDLF) of the wheel (RD) to refine the analysis of the motion state by the corresponding distance changes (D1SK, D2SK, D3SK, D1RDLF, D2RDLF, D3RDLF) to the contact area (GER) and to make corresponding fine-matching adjustments for idling or slipping on the rail vehicle.

6. The method according to any one of the preceding claims, wherein, Information about the determined operating type is transmitted to the drive control unit of the rail vehicle. And / or transmit to the braking control device of the rail vehicle so as to initiate the corresponding adjustment on the rail vehicle.

7. The method according to claim 6, in, When idling is detected, the traction force on the rail vehicle is reduced via the rail vehicle's drive control device to at least suppress idling, or When slippage is detected, the braking force on the rail vehicle is reduced by the braking control device of the rail vehicle in order to at least suppress slippage.

8. The method according to claim 1, wherein, Camera images are used to monitor and / or assess the track condition of a section of track.

9. The method according to any one of the preceding claims, wherein, As feature points (P1SK, P1RDLF), damage, surface changes, surface discoloration, and / or structures on a sub-region (RDLF) of the track (SCH) or wheel (RD) are used. Markers are used as feature points and are placed on sub-regions (SK) of the track (SCH) or sub-regions (RDLF) of the wheel (RD).

10. An apparatus for determining the motion state of wheels (RD) of a rail vehicle (SFZ), comprising: The rail vehicle (SFZ) has wheels (RD) and rails (SCH), the rails being traveled by the wheels (RD) of the rail vehicle (SFZ). A camera (KAM) is mounted on the rail vehicle (SFZ) and focuses on the wheel-rail area. The camera is configured to record successive images of a wheel-track region, wherein the wheel-track region includes at least one sub-region (RDLF) of the wheel (RD) of the rail vehicle (SFZ) and at least one sub-region (SK) of the track (SCH) to be traveled by the wheel (RD). The device also includes a component for image analysis, the component being designed to perform the method according to any one of claims 1 to 9.

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