Railway ballast bed compactness detection equipment

Abstract

The present application discloses a kind of railway ballast bed compactness detection equipment.The present application belongs to the technical field of ballast bed compactness measurement.Equipment includes track mechanism that can walk on track, is installed on the track mechanism to and fro walking mechanism, is installed on the to and fro walking mechanism positioning and scanning module and measurement execution mechanism, the measurement execution mechanism includes multiple multidimensional measurement units, each multidimensional measurement unit is actively inserted into ballast bed, is installed on the to and fro walking mechanism data processing module, the track mechanism, to and fro walking mechanism, positioning and scanning module, measurement execution mechanism are connected with data processing module.The present application realizes accurate, fast, continuous compactness detection, significantly improves detection efficiency and accuracy, provides reliable data support for track maintenance, ensures the bearing capacity and structural stability of ballast bed.

Description

A railway ballast bed compaction detection equipment Technical Field

[0001] This invention belongs to the technical field of ballast track compaction measurement, specifically, it relates to a railway ballast track compaction detection equipment. Background Technology

[0002] The compaction of ballast track is affected by factors such as ballast material, gradation, and porosity. Materials with low strength and poor wear resistance are easily worn into powder, leading to a decrease in compaction. Needle-shaped and flaky ballast particles can reduce interlocking force and decrease compaction. Both excessively high and low porosity will affect the compaction effect. Insufficient ballast compaction reduces longitudinal and lateral resistance, causing track creep and lateral instability, resulting in track irregularities and ultimately affecting train safety.

[0003] Methods for on-site determination of ballast bed density include the water filling method, nuclear density meter, and gamma-ray ballast bed density meter. The water filling method is prone to inaccurate results due to uneven ballast bed porosity. Both nuclear density meters and gamma-ray ballast bed density meters pose radiation risks and require special protection. Furthermore, the latter is sensitive to environmental humidity, which can affect the accuracy of the measurement. Later, some scholars studied a method and device for detecting the density of loose ballast ballast. However, this device has specific requirements for the flatness of the testing environment and the particle size distribution of the ballast, limiting its adaptability and making it unsuitable for large-scale, efficient testing. Summary of the Invention

[0004] This invention provides a railway ballast bed compaction detection equipment to achieve accurate, rapid, and continuous compaction detection, significantly improving detection efficiency and accuracy, providing reliable data support for track maintenance, and ensuring the load-bearing capacity and structural stability of the ballast bed.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A railway ballast bed compaction detection device includes a track-moving mechanism that can travel on the track, a reciprocating walking mechanism installed on the track-moving mechanism, a positioning and scanning module and a measurement execution mechanism installed on the reciprocating walking mechanism, the measurement execution mechanism including multiple multi-dimensional measurement units, each of the multi-dimensional measurement units actively inserted into the ballast bed, and a data processing module installed on the reciprocating walking mechanism. The track-moving mechanism, the reciprocating walking mechanism, the positioning and scanning module, and the measurement execution mechanism are all connected to the data processing module.

[0007] A further technical solution is that the track mechanism includes a frame disposed above the track, and a passive wheel set and an active wheel set are respectively installed at the front and rear ends of the lower end of the frame. The passive wheel set and the active wheel set both run on the two steel rails of the track, and a vehicle speed sensing module is installed on the frame and located at the active wheel set.

[0008] A further technical solution is that the reciprocating travel mechanism includes a mounting plate slidably mounted on the track mechanism along the length direction of the track mechanism, and a drive component is mounted at the lower end of the mounting plate. The drive component is connected to the track mechanism in a transmission manner, and the mounting plate can move along the length direction of the track mechanism under the drive of the drive component.

[0009] A further technical solution is that the positioning and scanning module includes a Beidou positioning system and two LiDAR scanners installed on the reciprocating walking mechanism. The two LiDAR scanners are respectively located on both sides of the reciprocating walking mechanism, and the Beidou positioning system and the two LiDAR scanners are all connected to the data processing module.

[0010] A further technical solution is that the multi-dimensional measurement unit includes a connecting part installed on the reciprocating walking mechanism, a vertical drive part installed at the lower end of the connecting part, a measuring component connected to the drive end of the vertical drive part through a transfer tube, a connecting plate connected between the drive end of the vertical drive part and the transfer tube, a first pressure sensor set between the connecting plate and the transfer tube, and a safety protection unit fitted around the measuring component.

[0011] A further technical solution is that the measuring component includes an end face measuring part, a circumferential measuring part, and a bottom measuring part that are sequentially installed vertically downwards on the probe body. The upper end of the probe body is installed on the lower end of the adapter pipe. An upper assembly part, a middle assembly part, and a lower assembly part are sequentially constructed vertically downwards on the probe body. The end face measuring part, the circumferential measuring part, and the bottom measuring part are assembled one-to-one with the upper assembly part, the middle assembly part, and the lower assembly part.

[0012] A further technical solution is that the end face measuring part includes a protective cover fitted outside the upper assembly part, a measuring disc movably fitted on the lower part of the upper assembly part, a compression spring provided between the measuring disc and the protective cover, the compression spring being fitted outside the upper assembly part; an assembly opening is provided on the peripheral wall of the upper assembly part, ceramic positioning seats are respectively fitted at the upper and lower ends of the assembly opening, a rod-shaped resistance wire and a free slide rail are installed side by side between the two ceramic positioning seats, an overcurrent slide bridge is slidably connected between the rod-shaped resistance wire and the free slide rail, and the overcurrent slide bridge is connected to the measuring disc.

[0013] A further technical solution is that the circumferential measuring part includes a conical elastic shell installed in the middle assembly part, and a strain resistance wire in a conical spiral shape is coaxially arranged in the conical elastic shell. The shape of the middle assembly part is the same as that of the conical elastic shell. Multiple strip holes are spaced apart on the peripheral wall of the middle assembly part. Each strip hole extends vertically. A rubber sealing gasket is provided between the middle assembly part and the conical elastic shell. The rubber sealing gasket extends out of the strip hole at the position of the strip hole.

[0014] A further technical solution is that the bottom measuring part includes a measuring probe movably connected to the lower end of the lower assembly part, and a second pressure sensor is installed inside the lower assembly part and at the upper end of the measuring probe.

[0015] A further technical solution is that the safety protection unit includes a limiting sleeve fitted outside the measuring component and connected to the drive end of the vertical drive unit. A limiting ring is coaxially arranged inside the limiting sleeve. The limiting ring is connected to the body of the vertical drive unit through two limiting columns. A normally closed on / off switch is installed on the limiting ring and the connecting plate respectively.

[0016] The technological advancements achieved by this invention compared to existing technologies, due to the adoption of the aforementioned structure, are as follows:

[0017] The track-traveling mechanism of this invention can move autonomously along the track without additional traction equipment. With a base travel speed of 4-5 km / h, it significantly reduces manual intervention and on-site setup time. The reciprocating travel mechanism drives the measurement execution mechanism to move back and forth along the length of the track mechanism, completing the location and measurement of detection points while the trolley is moving, eliminating the need to stop and wait. This enables continuous operation with simultaneous movement and measurement, improving detection efficiency several times over compared to traditional static detection methods. The measurement execution mechanism includes multiple multi-dimensional measurement units, allowing simultaneous detection of multiple points on both sides of the rail. Combined with the precise displacement control of the reciprocating travel mechanism, it can quickly cover the entire track, effectively solving the problems of traditional equipment that can only detect a single point at a time and that large-area detection is time-consuming.

[0018] Each multi-dimensional measurement unit can collect multi-dimensional data such as the degree of surface indentation, lateral extrusion pressure, and vertical force of the track bed. Combined with the comprehensive analysis of the data processing module, it avoids the one-sidedness of traditional single-index measurement and can more realistically reflect the distribution of track bed density. The positioning and scanning module provides high-precision position information, ensuring the traceability of the detection point coordinates, and scans the sleeper position and track bed outline in real time. On the one hand, it avoids collisions between the multi-dimensional measurement unit and the sleeper; on the other hand, it verifies the track bed deformation before and after detection, eliminates the interference of detection behavior on the data, and assists the data processing module in accurately setting the detection points, solving the problem of result distortion caused by detection position deviation in traditional detection.

[0019] Compared to traditional equipment such as nuclear density meters and gamma-ray track density meters, this invention acquires data through a combination of mechanical detection and electrical measurement, resulting in no radiation pollution and requiring no special protective measures, thus reducing health risks to workers and on-site safety management costs. It does not rely on a flat testing environment or a specific ballast particle size distribution; the multi-dimensional measurement unit can adapt to track bed conditions with different gradations and porosities, solving the problem of limited adaptability caused by uneven track bed porosity and the sensitivity of some testing equipment to environmental humidity in traditional water-filling methods.

[0020] The data processing module integrates vehicle speed information from the track mechanism, environmental information from the positioning and scanning modules, and multi-dimensional detection data from the measurement execution mechanism. It analyzes and generates compaction results in real time, while storing the coordinates of the detection points and the detection data, providing a complete and traceable data archive for track maintenance. Through continuous and precise compaction detection, weak sections of the track bed (such as areas with insufficient compaction) can be accurately identified, providing a clear and targeted basis for maintenance and repair. This avoids the resource waste caused by traditional comprehensive maintenance, ensures the load-bearing capacity and structural stability of the track bed, and indirectly guarantees train operation safety.

[0021] In summary, this invention achieves accurate, rapid, and continuous density detection, significantly improving detection efficiency and accuracy, providing reliable data support for track maintenance, and ensuring the load-bearing capacity and structural stability of the track bed. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0023] In the attached diagram:

[0024] Figure 1 is a schematic diagram of the structure of the present invention disposed on the track according to an embodiment of the present invention;

[0025] Figure 2 is a structural schematic diagram of an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of the track mechanism according to an embodiment of the present invention;

[0027] Figure 4 is a structural schematic diagram of the vehicle speed sensing module according to an embodiment of the present invention;

[0028] Figure 5 is a schematic diagram of the vehicle speed sensing module after the fixing shell is removed in an embodiment of the present invention;

[0029] Figure 6 is a partial structural schematic diagram of the track mechanism according to an embodiment of the present invention;

[0030] Figure 7 is a schematic diagram of the structure after removing the track mechanism in an embodiment of the present invention;

[0031] Figure 8 is a front view of the structure shown in Figure 7;

[0032] Figure 9 is a structural schematic diagram of the reciprocating walking mechanism according to an embodiment of the present invention;

[0033] Figure 10 is a schematic diagram of the structure of the multi-dimensional measurement unit according to an embodiment of the present invention;

[0034] Figure 11 is a schematic diagram of the structure of the multi-dimensional measurement unit after removing the limiting sleeve in an embodiment of the present invention;

[0035] Figure 12 is a partial axial structural cross-sectional view of the multi-dimensional measurement unit according to an embodiment of the present invention;

[0036] Figure 13 is an axial structural cross-sectional view of the connection between the vertical drive unit and the transfer tube in an embodiment of the present invention;

[0037] Figure 14 is a partial structural schematic diagram of the end face measuring part according to an embodiment of the present invention;

[0038] Figure 15 is a schematic diagram of the strain resistance wire in the circumferential measuring section of an embodiment of the present invention;

[0039] Figure 16 is a schematic diagram of the structure of the measurement component according to an embodiment of the present invention;

[0040] Figure 17 is a schematic diagram of the structure of the security protection unit according to an embodiment of the present invention;

[0041] Figure 18 is a schematic diagram of the structure of the measuring probe in the bottom measuring section of an embodiment of the present invention;

[0042] Figure 19 is a schematic diagram of the probe body according to an embodiment of the present invention;

[0043] Figure 20 is a schematic diagram of the circumferential measuring section according to an embodiment of the present invention;

[0044] Figure 21 shows the stress situation of the outer shell to which the strain resistance wire is attached in the circumferential measuring part of the present invention. (a) is a schematic diagram of the outer shell being uniformly stressed, and (b) is a schematic diagram of the outer shell being unevenly stressed.

[0045] Figure 22 is a schematic diagram of the structure of the safety protection unit in contact with the upper surface of the sleeper according to an embodiment of the present invention;

[0046] Figure 23 is a schematic diagram of the structure of the safety protection unit in contact with the side of the sleeper according to an embodiment of the present invention;

[0047] Figure 24 is a schematic diagram of the structure of the safety protection unit in an embodiment of the present invention in a non-contact state with the sleeper.

[0048] Components marked: 100-Rail mechanism, 101-Frame, 102-Front axle, 103-Front rail wheel, 104-First motor reducer, 105-Rear axle, 106-Electrical distribution box, 107-Fixed housing, 108-Rear rail wheel, 109-Wireless signal transmitter, 110-Speed ​​counting gear, 111-Hall sensor, 112-Transmission rack, 113-Guide rail, 114-Mounting base, 200-Towards Return travel mechanism, 201-mounting plate, 202-counterweight block, 203-slide block, 204-second motor reducer, 205-connecting shaft, 206-transmission gear, 300-multi-dimensional measurement unit, 301-connecting part, 302-cylinder body, 303-adapter pipe, 304-connecting plate, 305-connecting flange, 306-first pressure sensor, 307-upper assembly part, 308-middle assembly part, 30 9-Lower assembly part, 310-Limiting flange, 311-Guard cover, 312-Measuring disc, 313-Compression spring, 314-Assembly port, 315-Ceramic positioning seat, 316-Rod-shaped resistance wire, 317-Unobstructed slide rail, 318-Electrical sliding bridge, 319-Strip hole, 320-Conical elastic housing, 321-Strain gauge wire, 322-Rubber sealing gasket, 323-Second pressure sensor, 324-Measuring probe 325-Connecting column, 326-Anti-loosening installation slide, 327-Ball bearing, 328-Assembly hole, 329-Limit sleeve, 330-Limit ring, 331-Limit column, 332-Normally closed on / off switch, 333-Cylinder rod, 400-Hydraulic station, 500-LiDAR scanner, 501-Bracket, 600-BeiDou positioning system, 700-Data processing module, 800-Rail, 900-Sleeper. Detailed Implementation

[0049] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0050] This invention discloses a railway ballast bed compaction detection equipment, as shown in Figures 1-23. It includes a track-moving mechanism 100 that can travel on the track, a reciprocating walking mechanism 200 mounted on the track-moving mechanism 100, and a positioning and scanning module and a measurement execution mechanism mounted on the reciprocating walking mechanism 200. The measurement execution mechanism includes multiple multi-dimensional measurement units 300, each of which actively inserts into the ballast bed. A data processing module 700 is mounted on the reciprocating walking mechanism 200, and the track-moving mechanism 100, the reciprocating walking mechanism 200, the positioning and scanning module, and the measurement execution mechanism are all connected to the data processing module 700.

[0051] The track-traveling mechanism 100 of this invention can move autonomously along the track without additional traction equipment. With a basic travel speed of 4-5 km / h, it significantly reduces manual intervention and on-site setup time. The reciprocating travel mechanism 200 drives the measurement execution mechanism to reciprocate along the length of the track-traveling mechanism 100. Detection point positioning and measurement can be completed during the trolley's movement without stopping, enabling continuous operation while moving and measuring. Compared to traditional static detection methods, detection efficiency is improved several times. The measurement execution mechanism includes multiple multi-dimensional measurement units 300, which can simultaneously detect multiple detection points on both sides of the rail 800. Combined with the precise displacement control of the reciprocating travel mechanism 200, it can quickly cover the entire track, effectively solving the problems of traditional equipment that can only detect a single point at a time and that large-area detection is time-consuming.

[0052] Each multi-dimensional measurement unit 300 can collect multi-dimensional data such as the degree of surface indentation, lateral extrusion pressure, and vertical force of the track bed. Combined with the comprehensive analysis of the data processing module 700, it avoids the one-sidedness of traditional single-index measurement and can more realistically reflect the distribution of track bed density. The positioning and scanning module provides high-precision position information, ensuring the traceability of the detection point coordinates, and scans the position of the sleeper 900 and the track bed outline in real time. On the one hand, it avoids collisions between the multi-dimensional measurement unit 300 and the sleeper 900, and on the other hand, it verifies the deformation of the track bed before and after detection, eliminates the interference of detection behavior on the data, and assists the data processing module 700 in accurately setting the detection points, solving the problem of result distortion caused by detection position deviation in traditional detection.

[0053] Compared to traditional equipment such as nuclear density meters and gamma-ray track density meters, this invention acquires data through a combination of mechanical detection and electrical measurement, resulting in no radiation pollution and requiring no special protective measures, thus reducing health risks to workers and on-site safety management costs. It does not rely on a flat testing environment or a specific ballast particle size distribution; the multi-dimensional measurement unit 300 can adapt to track bed conditions with different gradations and porosities, solving the problem of limited adaptability caused by uneven track bed porosity and the sensitivity of some testing equipment to environmental humidity in traditional water-filling methods.

[0054] The data processing module 700 integrates the vehicle speed information from the track mechanism 100, the environmental information from the positioning and scanning modules, and the multi-dimensional detection data from the measurement execution mechanism. It analyzes and generates compaction results in real time, while storing the coordinates of the detection points and the detection data, providing a complete and traceable data archive for track maintenance. Through continuous and precise compaction detection, weak sections of the track bed (such as areas with insufficient compaction) can be accurately identified, providing a clear and targeted basis for maintenance and repair. This avoids the resource waste caused by traditional comprehensive maintenance, ensures the load-bearing capacity and structural stability of the track bed, and indirectly guarantees train operation safety.

[0055] In summary, this invention achieves accurate, rapid, and continuous density detection, significantly improving detection efficiency and accuracy, providing reliable data support for track maintenance, and ensuring the load-bearing capacity and structural stability of the track bed.

[0056] As a preferred embodiment of the present invention, as shown in Figures 3-5, the track-traveling mechanism 100 includes a frame 101 disposed above the track. A passive wheel set and a driving wheel set are respectively installed at the front and rear ends of the lower end of the frame 101. Both the passive and driving wheel sets run on two steel rails 800 of the track. A speed sensing module is installed on the frame 101, located at the driving wheel set. The passive wheel set includes a front axle 102 rotatably mounted on the frame 101, with two front rail wheels 103 mounted on the front axle 102. The driving wheel set includes a rear axle 105 rotatably mounted on the frame 101, with two rear rail wheels 108 mounted on the rear axle 105. A power distribution box 106 and a first motor reducer 104 are installed at the rear end of the frame 101, and the rear axle 105 is drive-connected to the first motor reducer 104. The vehicle speed sensing module includes a speed measuring gear 110 coaxially mounted on the rear axle 105, and a Hall sensor 111 disposed above the speed measuring gear 110. A mounting housing 107 is mounted on the frame 101, and both the speed measuring gear 110 and the Hall sensor 111 are located inside the mounting housing 107. A wireless signal transmitter 109 is mounted outside the mounting housing 107.

[0057] In this embodiment, the track-tracing mechanism 100, through the collaborative design of the frame 101, passive wheel sets, active wheel sets, and speed sensing module, combined with the optimization of the transmission and protection structures, achieves multiple beneficial effects in ensuring stable equipment operation, accurate feedback of working conditions, and adaptability to track inspection scenarios. The passive and active wheel sets are symmetrically installed at the front and rear ends of the frame 101, respectively, and both travel on two steel rails 800, forming a four-point support structure. This effectively distributes the equipment weight and avoids unilateral force imbalance. Simultaneously, the close fit design of the passive and active wheel sets with the steel rails 800 ensures the equipment travels along the track in a directional manner, eliminating the risk of deviation and rollover, providing a stable foundation for subsequent accurate measurements, and adapting to long-distance continuous inspection scenarios. The rear axle 105 is directly connected to the first motor reducer 104, resulting in a short power transmission path and low loss, providing continuous and uniform travel power to the equipment. Combined with a stable travel speed of 4-5 km / h, this avoids disruption of the inspection rhythm due to power fluctuations, ensuring the efficient implementation of continuous operation modes that involve moving and measuring simultaneously.

[0058] The vehicle speed sensing module in this embodiment adopts a combined structure of a speed-measuring gear 110 and a Hall sensor 111. The speed-measuring gear 110 is coaxially mounted on the rear axle 105, and the rear track wheel 108 rotates synchronously. The Hall sensor 111 generates a pulse signal by sensing the periodic changes in the teeth of the speed-measuring gear 110, which can accurately capture the rotational speed of the rear track wheel 108 and then calculate the equipment's travel speed. Compared with traditional speed measurement methods, this structure is not affected by dust or humidity on the track surface, has a small speed measurement error, and can provide real-time and accurate vehicle speed data for the data processing module 700. The wireless signal transmitter 109 outside the fixed housing 107 transmits vehicle speed data to the data processing module 700 in real time, ensuring that the data processing module 700 accurately grasps the equipment's movement status. This allows the module to control the reciprocating walking mechanism 200 and the measuring track mechanism 100 to move in opposite directions at the same speed, keeping the multi-dimensional measurement unit 300 stationary relative to the ground. This creates stable conditions for the multi-dimensional measurement unit 300 to vertically insert into the track bed and accurately collect data, avoiding detection point offset and measurement data distortion caused by vehicle speed feedback delay. The speed measuring gear 110 and the Hall sensor 111 are both housed within the fixed housing 107 on the frame 101. The fixed housing 107 effectively isolates ballast particles, dust, rainwater, and other impurities in the track working environment, preventing contamination of the Hall sensor 111 or wear of the speed measuring gear 110. This ensures the long-term stable operation of the vehicle speed sensing module and reduces equipment maintenance frequency and costs.

[0059] In this embodiment, the passive wheel assembly, active wheel assembly, speed sensing module, and power distribution box 106 are all independently assembled on the frame 101. The clear division of labor and neat layout not only simplify the equipment assembly process but also facilitate subsequent maintenance and replacement of individual components without requiring overall disassembly, thus improving maintenance efficiency. The front rail wheels 103 and rear rail wheels 108 are structurally designed to match the contour of the rail 800, ensuring a close fit during movement and preventing slippage and derailment. Furthermore, the front rail wheels 103 and rear rail wheels 108 are made of wear-resistant and pressure-resistant materials, capable of withstanding the wear and tear of long-term track operation and ensuring the safety of the equipment under different track conditions. The power distribution box 106 at the rear of the frame 101 integrates electrical control components and power supply-related parts, enabling centralized management of the power supply system and avoiding short circuits and leakage risks caused by messy wiring. Simultaneously, the independent layout facilitates separate protection and maintenance of the power supply system, further enhancing the electrical safety of the equipment operation.

[0060] As a preferred embodiment of the present invention, as shown in Figures 6-9, the reciprocating travel mechanism 200 includes a mounting plate 201, which is slidably mounted on the track mechanism 100 and can slide along the length direction of the track mechanism 100 under drive. A drive assembly is mounted at the lower end of the mounting plate 201, which is driveably connected to the track mechanism 100, and the mounting plate 201 can move along the length direction of the track mechanism 100 under the drive of the drive assembly. The drive assembly includes a connecting shaft 205, which extends laterally along the frame 101. Two transmission gears 206 are mounted on the connecting shaft 205 at axial intervals, and the connecting shaft 205 is driveably connected to a second motor reducer 204 mounted at the lower end of the mounting plate 201. Two sets of slides 203 are mounted on both sides of the mounting plate 201. Two drive racks 112 and two guide rails 113 are mounted side by side on the frame 101. Both the drive racks 112 and the guide rails 113 extend along the length of the frame 101, and the guide rails 113 and the drive racks 112 are connected to the frame 101 via mounting bases 114. The drive gears 206 mesh with the corresponding drive racks 112, and the guide rails 113 are slidably connected to the corresponding slides 203.

[0061] In this embodiment, the reciprocating travel mechanism 200 uses a coordinated mechanism of motor drive, gear and rack transmission, and guide rail 113 to achieve precise reciprocating motion of the mounting plate 201 along the length of the track mechanism 100. The specific workflow is as follows:

[0062] 1. After the second motor reducer 204 starts, it transmits power to the laterally extending connecting shaft 205, driving the connecting shaft 205 to rotate around its own axis;

[0063] 2. Two transmission gears 206 installed at intervals on the connecting shaft 205 rotate synchronously with the shaft. Since the transmission gears 206 mesh with the transmission racks 112 on the frame 101 of the track mechanism 100, the rotational motion of the transmission gears 206 is converted into a linear driving force along the length of the transmission racks 112 through the meshing relationship.

[0064] 3. The two sets of slide blocks 203 at the lower end of the mounting plate 201 are slidably engaged with the two guide rails 113 on the frame 101. The guide rails 113 extend along the length of the frame 101 to provide guidance and constraint for the linear movement of the mounting plate 201, and to avoid deviation or jamming during the movement.

[0065] 4. Under the instruction of the data processing module 700, the second motor reducer 204 can rotate in both directions, driving the mounting plate 201 to slide back and forth along the guide rail 113. At the same time, combined with the vehicle speed data of the track mechanism 100, the movement speed and stroke of the mounting plate 201 are precisely adjusted to ensure that the relative movement between the multi-dimensional measurement unit 300 and the track mechanism 100 meets the detection requirements.

[0066] This embodiment employs a symmetrical meshing design of two transmission gears 206 and corresponding transmission racks 112, with a constant transmission ratio. This accurately converts the rotational motion of the second motor reducer 204 into linear motion, avoiding slippage and step loss, and ensuring the displacement accuracy of the mounting plate 201. Simultaneously, the transmission gears 206 and racks 112 have strong load-bearing capacity, stably supporting all components on the mounting plate 201, including the positioning and scanning module and the measurement execution mechanism. Even when the multi-dimensional measurement unit 300 experiences a reaction force during its downward movement, it maintains stable motion, providing a stable detection reference for the multi-dimensional measurement unit 300. The cooperative structure of two parallel guide rails 113 and two sets of slides 203 provides double constraint on the movement direction of the mounting plate 201 from both sides, effectively limiting the lateral offset and torsion of the mounting plate 201. This ensures that the mounting plate 201 always moves linearly along the length of the track mechanism 100, preventing angular deviations in the insertion angle of the multi-dimensional measurement unit 300 into the track bed due to motion posture deviations, and guaranteeing the accuracy of the detection data. The transmission gear 206, transmission rack 112, guide rail 113, and slide 203 all adopt a symmetrical layout. Two counterweights 202 are symmetrically installed on the mounting plate 201 along its transverse direction, so that the force on the mounting plate 201 is evenly distributed, avoiding component wear or movement jamming caused by excessive force on one side, and extending the service life of the mechanism. At the same time, the balanced force state can reduce the local stress impact on the frame 101 of the rail mechanism 100, ensuring the structural stability of the entire equipment.

[0067] In this embodiment, the second motor reducer 204 is directly connected to the connecting shaft 205, resulting in a short power transmission path and low loss. The start / stop and speed adjustment of the second motor reducer 204 can be quickly translated into changes in the motion state of the mounting plate 201. Combined with the instructions from the data processing module 700, the mounting plate 201 and the track mechanism 100 can move in opposite directions at the same speed (i.e., the measuring unit is stationary relative to the ground), accurately matching the detection timing and ensuring the efficient implementation of the continuous operation mode of moving and measuring simultaneously. Through the forward and reverse rotation control of the second motor reducer 204, the mounting plate 201 can slide freely back and forth along the length of the track mechanism 100 without the need for an additional reversing mechanism, simplifying the motion control logic. After a single detection is completed, the measuring unit can be quickly driven back to the initial position to prepare for the next detection, shortening the detection cycle and improving the overall detection efficiency.

[0068] In this embodiment, the sliding connection between the guide rail 113 and the slide block 203 has a certain buffer margin, which can adapt to slight bumps in the track working environment and avoid mechanism jamming or component damage caused by uneven road surface. At the same time, the wear-resistant design of the slide block 203 can cope with the influence of dust, ballast particles and other impurities in the track environment, ensuring the stable operation of the mechanism under complex working conditions. The motion status (speed, position) of the reciprocating travel mechanism 200 is fed back to the data processing module 700 in real time, and is linked with the speed sensing module, positioning and scanning module of the track mechanism 100 to obtain the sleeper 900 position data. When obstacles such as sleepers 900 are detected at the detection point, the position of the mounting plate 201 can be quickly adjusted to avoid collision between the measuring execution mechanism and the obstacle, thereby improving operational safety.

[0069] As a preferred embodiment of the present invention, as shown in Figures 1, 2, and 7, the positioning and scanning module includes a Beidou positioning system 600 and two LiDAR scanners 500 mounted on the reciprocating walking mechanism 200. The two LiDAR scanners 500 are respectively arranged on both sides of the reciprocating walking mechanism 200. Each LiDAR scanner 500 is connected to the mounting plate 201 through a bracket 501. The Beidou positioning system 600 and the two LiDAR scanners 500 are all connected to the data processing module 700.

[0070] In this embodiment, the positioning and scanning module uses a collaborative mode of BeiDou positioning and dual lidar scanning, combined with real-time linkage with the data processing module 700, to achieve precise location locking, comprehensive perception of the orbital environment, and dynamic calibration of the measurement process. The specific workflow is as follows:

[0071] The BeiDou Positioning System 600 achieves precise location locking: The BeiDou Positioning System 600 (including the BeiDou signal receiver and RTK module) receives satellite signals in real time and, combined with RTK differential positioning technology, accurately acquires the three-dimensional coordinate information (longitude, latitude, and elevation) of the reciprocating walking mechanism 200 (and its onboard measurement actuator), transmitting the location data to the data processing module 700 in real time. The data processing module 700 uses this coordinate information to determine the specific mileage location of the equipment on the track, providing fundamental data for precise marking of detection points and subsequent maintenance tracking.

[0072] Two lidar scanners 500 are positioned on either side of the reciprocating travel mechanism 200, continuously emitting laser beams along the track extension direction to perform a 360° scan of the track bed surface, sleepers 900, rails 800, and other structures on both sides of the track. The lidar scanners 500 acquire the distance, outline, and position information of target objects by receiving reflected laser signals. By scanning the geometric outline of the sleepers 900 (rectangular block structure, height difference with the track bed), the spacing, arrangement, and specific position coordinates of the sleepers 900 are accurately determined, and the data is transmitted to the data processing module 700 to prevent collisions between the multi-dimensional measurement unit 300 and the sleepers 900 during the detection process. The lidar scanners also scan the track bed surface outline before and after the detection point in real time, recording the height, width, and surface flatness data of the track bed, providing an environmental reference for the accuracy verification of subsequent compaction test results.

[0073] The data processing module 700 integrates the mileage information from the Beidou positioning system 600 with the sleeper 900 and track bed data scanned by the lidar scanner 500, and performs comprehensive analysis and command issuance.

[0074] 1. Detection point planning: Based on the preset detection interval (e.g., one detection point is set every 1 meter), combined with the mileage position of the Beidou positioning system 600, effective detection points that avoid the sleeper 900 are selected.

[0075] 2. Dynamic calibration: During the equipment's movement, the position of the sleeper 900 scanned by the LiDAR scanner 500 is compared with the coordinates of the preset detection point in real time. If the detection point is deviated due to track offset or equipment vibration, the movement trajectory of the reciprocating walking mechanism 200 is adjusted in time to ensure that the multi-dimensional measurement unit 300 is accurately aligned with the detection point.

[0076] 3. Result verification: Compare the track bed contour data before and after the detection to determine whether the 300-degree multi-dimensional measurement unit insertion caused significant deformation of the track bed surface. If the deformation exceeds the allowable range, mark the detection data as invalid to avoid misjudging the track bed density.

[0077] This embodiment employs the BeiDou positioning system 600 combined with an RTK module, achieving centimeter-level positioning accuracy. It precisely marks the mileage position of each detection point, solving the problems of ambiguous and untraceable detection point locations in traditional detection methods, and providing accurate targeted location data for track maintenance. The lidar scanners 500 on both sides simultaneously scan the track area, covering all areas without blind spots. This accurately identifies sleepers 900 of different spacing and types, avoiding overlap between detection points and sleepers 900 caused by blind spots on one side. This ensures that the multi-dimensional measurement unit 300 only probes within the effective area of ​​the track bed, improving the effectiveness of the detection data.

[0078] The track bed contour data scanned by the LiDAR scanner 500 can not only help determine whether the detection point is within the effective area of ​​the track bed, but also assess the impact of the detection behavior on the track bed (such as whether it causes ballast loosening or over-compaction) by comparing the contours before and after detection. If the impact exceeds the threshold, the data is discarded to avoid misjudgment of density due to detection interference. This solves the problem in traditional inspections of not being able to distinguish between the density of the track bed itself and the density changes caused by detection interference. Both the BeiDou positioning system 600 and the LiDAR scanner 500 are unaffected by factors such as dust, rainwater, and uneven ballast particle size in the track environment. Compared with traditional inspection equipment that depends on the smoothness of the environment, they can work stably in complex weather and complex track bed conditions, and have wider adaptability.

[0079] The positioning and scanning module transmits location and environmental data to the data processing module 700 in real time. The data processing module 700 synchronously controls the traveling speed of the track-moving mechanism 100, the reverse movement of the reciprocating walking mechanism 200, and the insertion timing of the measurement execution mechanism. This ensures that the measurement unit remains aligned with the effective detection point and stationary relative to the ground throughout the equipment's movement, achieving continuous and efficient on-the-go measurement. The detection efficiency is several times higher than traditional static detection. The lidar scanner 500 identifies obstacles such as sleepers 900 and rail 800 joints in advance. The data processing module 700 promptly adjusts the position of the multi-dimensional measurement unit 300 to avoid collisions with obstacles, significantly reducing the risk of equipment damage and improving on-site operational safety.

[0080] In this embodiment, the positioning and scanning module provides the detection point mileage coordinates, sleeper 90mm distribution data, and track bed contour data. These, along with the compaction data from the measurement actuator, form a complete dataset. Maintenance personnel can combine the mileage location to query the track bed status (compaction, contour shape, sleeper 90mm distribution) of the corresponding area, comprehensively assessing the track health status and avoiding the one-sidedness of maintenance decisions caused by relying solely on compaction data. All positioning and scanning data are stored synchronously with the compaction data, forming a long-term monitoring archive for the track line. By comparing data from different periods, the changing trend of track bed compaction can be analyzed (e.g., whether it decreases year by year, which sections decay faster), providing a scientific basis for preventive maintenance and reducing the risk of traffic safety problems caused by track bed failure.

[0081] As a preferred embodiment of the present invention, as shown in Figures 10-19, the multi-dimensional measurement unit 300 includes a connecting portion 301 mounted on the reciprocating walking mechanism 200, and a vertical drive portion mounted at the lower end of the connecting portion 301. This vertical drive portion is a hydraulic cylinder, which is connected to a hydraulic station 400 mounted on the mounting plate 201. The cylinder rod 333 of the hydraulic cylinder is a hollow tubular structure to allow various wires to extend through the tubular structure. A connecting pipe 303 is inserted into the lower end of the cylinder rod 333, and a connecting flange 305 is constructed at the lower end of the connecting pipe 303. A connecting joint is constructed at the center of the lower end of the connecting flange 305, and this connecting joint connects to the measurement component. A connecting plate 304 is connected between the cylinder rod 333 and the connecting pipe 303, and a first pressure sensor 306 is disposed between the connecting plate 304 and the connecting flange 305 of the connecting pipe 303. A safety protection unit is fitted around the measurement component. The measuring assembly includes an end face measuring section, a circumferential measuring section, and a bottom measuring section, which are sequentially mounted vertically downwards on the probe body. The upper end of the probe body is mounted on a connecting joint at the lower end of the adapter pipe 303. An upper assembly section 307, a middle assembly section 308, and a lower assembly section 309 are sequentially constructed vertically downwards on the probe body, with the end face measuring section, circumferential measuring section, and bottom measuring section corresponding to the upper assembly section 307, middle assembly section 308, and lower assembly section 309 respectively.

[0082] This embodiment's multi-dimensional measurement unit 300 achieves multiple optimizations in terms of density detection accuracy, operational safety, and environmental adaptability through a hydraulically driven, multi-module collaborative measurement, and protective adaptive structural design. The vertical drive unit uses a hydraulic cylinder, which, in conjunction with the hydraulic station 400, can precisely adjust the downward pressure (e.g., a preset 10MPa pressure) and speed, avoiding the impact of mechanical drive and allowing the measuring components to slowly penetrate the ballast, reducing disturbance to the original track bed structure and ensuring that the measurement data accurately reflects the original density of the track bed. The cylinder rod 333 is designed as a hollow tubular structure to accommodate various wires of the measuring components (such as the connecting wires of the pressure sensor and strain resistance wire 321), preventing exposed wires from being damaged by ballast friction and compression. It also ensures neat wiring, reduces interference with the movement of the measuring components, and improves the long-term reliability of the equipment. The first pressure sensor 306 between the connecting plate 304 and the adapter pipe 303 can capture pressure changes in real time during the probing process. Together with the data processing module 700, it can accurately control the probing depth and force, avoid excessive compaction of ballast or damage to the measuring components due to excessive pressure, and ensure the controllability of the probing process.

[0083] This embodiment integrates three measuring units: an end face measuring unit, a circumferential measuring unit, and a bottom measuring unit. These units respectively detect the degree of surface indentation, lateral extrusion pressure, and vertical force on the track bed. Through multi-dimensional data cross-validation, it avoids the one-sidedness of traditional single-index measurements and can more comprehensively and accurately reflect the distribution of track bed density. The upper assembly part 307, middle assembly part 308, and lower assembly part 309 of the probe body are assembled one-to-one with the three measuring units, ensuring precise structural positioning and reducing mutual interference between the measuring units. At the same time, the modular design facilitates the individual calibration of the accuracy of each measuring unit, ensuring the accuracy of data acquisition from each module and providing a reliable foundation for comprehensive analysis. The detection data from the three measuring units are transmitted to the data processing module 700 in real time. Combined with preset mapping relationships (such as the correlation formulas between current and density, and displacement and density), comprehensive calculations are performed to accurately calculate the track bed density value, solving the problem of misjudgment caused by single data in traditional detection methods.

[0084] As a preferred embodiment of the present invention, as shown in Figures 12, 14, and 16, the end face measuring part includes a protective cover 311 fitted over the upper assembly part 307. A measuring disc 312 is movably fitted over the lower part of the upper assembly part 307. A compression spring 313 is provided between the measuring disc 312 and the protective cover 311, and the compression spring 313 is fitted over the upper assembly part 307. An assembly opening 314 is provided on the peripheral wall of the upper assembly part 307. Ceramic positioning seats 315 are respectively installed at the upper and lower ends of the assembly opening 314. A rod-shaped resistance wire 316 and a free-flowing slide rail 317 are installed side by side between the two ceramic positioning seats 315. An overcurrent slide bridge 318 is slidably connected between the rod-shaped resistance wire 316 and the free-flowing slide rail 317, and the overcurrent slide bridge 318 is connected to the measuring disc 312. Furthermore, a limiting flange 310 is provided between the upper assembly part 307 and the middle assembly part 308, and the lower end of the metering disc 312 is limited by the limiting flange.

[0085] In this embodiment, the end-face measurement unit uses a coordinated mechanism of mechanical linkage, resistance change, and data feedback to accurately capture the degree of surface depression of the track bed, and then infer the compactness. The specific process is as follows:

[0086] 1. Force-triggered linkage: When the measuring component moves downward with the vertical drive unit, the measuring plate 312 first contacts the track bed surface. The subsequent downward force causes the probe body to continue moving downward, while the measuring plate 312 moves upward relative to the track bed due to the reaction force of the track bed. At the same time, it compresses the compression spring 313 mounted on the upper assembly part 307.

[0087] 2. Resistance signal conversion: When the metering plate 312 moves upward, the overcurrent slide bridge 318 connected to it slides synchronously along the unobstructed slide rail 317 between the ceramic positioning seats 315. At the same time, the overcurrent slide bridge 318 contacts the rod-shaped resistance wire 316 installed side by side. During the sliding process, the connection length of the rod-shaped resistance wire 316 is changed, so that the resistance value in the circuit changes linearly.

[0088] 3. Data conversion to density: The change in resistance value is transmitted to the data processing module 700 through the line. Combined with the resistance change, displacement of the metering plate 312, and the mapping relationship of density fitted by indoor and field tests, the degree of indentation of the track bed surface under the set pressure is calculated, which is finally used as one of the key bases for density judgment.

[0089] In this embodiment, the sliding fit between the electric sliding bridge 318 and the unobstructed slide rail 317 reduces frictional resistance, ensuring that the displacement of the measuring disc 312 is accurately transmitted to the rod-shaped resistance wire 316. The change in resistance corresponds linearly to the amount of displacement, avoiding measurement errors caused by mechanical jamming. The ceramic positioning seat 315 combines insulation and wear resistance, fixing the installation position of the rod-shaped resistance wire 316 and the unobstructed slide rail 317 to prevent their displacement from affecting measurement accuracy. It also prevents short circuits or component corrosion caused by ballast dust and moisture, ensuring long-term measurement stability. The compression spring 313 always provides downward preload to the measuring disc 312, ensuring that the measuring disc 312 is in close contact with the ballast surface. At the same time, after the detection is completed, it pushes the measuring disc 312 to quickly reset, preparing for the next measurement and avoiding residual displacement from interfering with subsequent data.

[0090] In this embodiment, the protective cover 311 is fitted outside the upper assembly part 307, effectively preventing ballast particles and dust from entering the assembly port 314, avoiding collisions and wear to precision components such as the rod-shaped resistance wire 316 and the overcurrent sliding bridge 318, thus extending their service life. The end face measuring part is precisely assembled with the probe body through the upper assembly part 307, with a high degree of modularity. It can be disassembled individually for accuracy calibration or component replacement without the need for overall disassembly of the measuring components, reducing maintenance costs. After the measuring disc 312 contacts the track bed, it can instantly trigger displacement and resistance changes with no signal feedback delay. Combined with the real-time calculation of the data processing module 700, it can quickly complete single-point measurement, adapting to the continuous operation mode of measuring while moving. The elastic design of the compression spring 313 and the linear adjustment range of the rod-shaped resistance wire 316 can adapt to the concavity characteristics of track beds with different densities. Whether the track bed has high density (small concavity) or low density (large concavity), it can accurately capture displacement signals, avoiding limitations on the measurement range.

[0091] The end face measuring unit in this embodiment is specifically designed to detect the degree of indentation on the track bed surface under a set pressure. It complements the lateral compressive force of the circumferential measuring unit and the vertical force of the bottom measuring unit, forming a multi-dimensional data set that avoids the limitations of measuring a single indicator. The displacement data from the end face measuring unit is synchronously transmitted to the data processing module 700 along with data from other measuring units. Through comprehensive analysis and the elimination of outliers, the final compaction determination is more comprehensive and accurate, providing a reliable basis for track maintenance.

[0092] As a preferred embodiment of the present invention, as shown in Figures 12, 14, 15, 19, 20, and 21, the circumferential measuring unit includes a conical elastic housing 320 installed within a central assembly portion 308. A strain resistance wire 321 in a conical spiral shape is coaxially disposed within the conical elastic housing 320. The central assembly portion 308 has the same shape as the conical elastic housing 320. Multiple strip-shaped holes 319 are spaced apart on the peripheral wall of the central assembly portion 308, each extending vertically. A rubber sealing gasket 322 is provided between the central assembly portion 308 and the conical elastic housing 320, extending out of the strip-shaped holes 319 at their respective locations.

[0093] In this embodiment, the circumferential measuring unit, through an integrated design of a conical sensing structure, strip-shaped hole 319 for unloading, and sealed protection, accurately captures the lateral extrusion force of the ballast, achieving multiple optimizations in measurement sensitivity, environmental adaptability, and structural reliability. The conical elastic shell 320 and the central assembly part 308 have a matching conical design. The lateral force applied by the ballast is amplified when transmitted through the conical surface, causing the conical elastic shell 320 to undergo significant contraction deformation, which in turn drives the internal coaxial conical strain resistance wire 321 to shorten synchronously. Compared with the cylindrical structure, the conical design has higher force transmission efficiency. Even the small lateral pressure of low-density track bed can be converted into significant deformation of the conical strain resistance wire 321, greatly improving the detection sensitivity. The strain resistance wire 321 adopts a conical shape that fits the conical elastic shell 320 and has a multi-turn tower-shaped spiral structure, which can comprehensively capture the overall contraction deformation of the conical elastic shell 320. The resistance change of the tapered strain gauge wire 321 is linearly correlated with the degree of deformation. By converting the signals of deformation, resistance and current, the lateral extrusion pressure of ballast can be accurately quantified, providing reliable data support for density calculation.

[0094] In this embodiment, the vertically spaced slots 319 on the periphery of the assembly section 308 reduce the constraint of the rigid structure on the conical elastic shell 320, allowing the conical elastic shell 320 to respond more freely to the lateral force of the ballast, avoiding deformation lag or signal distortion caused by excessive structural rigidity. Simultaneously, the slots 319 extend vertically, not affecting the longitudinal load-bearing capacity of the assembly section 308, ensuring overall structural stability. The rubber sealing gasket 322 between the assembly section 308 and the conical elastic shell 320, with its portion extending out of the slots 319, directly contacts the ballast. This not only prevents ballast particles and dust from entering the interior through the slots 319, protecting the conical elastic shell 320 and the strain resistance wire 321 from wear and contamination, but also buffers the instantaneous impact of the ballast through the elasticity of the rubber sealing gasket 322, reducing the impact of local stress concentration on measurement accuracy. Even if the edges of the rubber sealing gasket 322 wear due to friction, it can still maintain its core sealing effect, adapting to complex track bed conditions.

[0095] In this embodiment, the lateral force exerted by the ballast on the circumferential measuring unit is often unevenly distributed. However, the overall contraction characteristics of the conical elastic shell 320 and the multi-turn spiral structure of the strain resistance wire 321 can transform the uneven local force into an overall average deformation. Regardless of whether the lateral force on the ballast is uniform, the total deformation of the strain resistance wire 321 is only related to the average force, avoiding measurement errors caused by local force fluctuations and ensuring stable data output even in scenarios with uneven ballast gradation and chaotic particle distribution. By combining mechanical deformation with electrical sensing, it does not rely on radiation or medium conduction and is unaffected by the humidity and dust content of the track bed environment. Compared with traditional equipment such as gamma-ray track bed density meters, it has wider adaptability and can work normally under complex conditions such as rainy days and wet track beds.

[0096] In this embodiment, the conical elastic housing 320 and the central assembly 308 are shaped and precisely assembled in a modular manner, ensuring the coaxiality and fit between the strain resistance wire 321 and the conical elastic housing 320, reducing the impact of assembly errors on measurement accuracy. Simultaneously, the modular design allows for the individual disassembly of the circumferential measuring section for accuracy calibration or component replacement without requiring overall disassembly of the measuring assembly, reducing maintenance costs. The central assembly 308 provides rigid support, and the conical elastic housing 320, made of elastic material, combines deformation sensitivity with structural strength, capable of withstanding long-term repeated ballast compression and recovery, extending its service life. The strain resistance wire 321 is encapsulated within the conical elastic housing 320, preventing direct contact with the external environment, further enhancing durability and stability.

[0097] This embodiment specifically detects the lateral compressive force of ballast on the circumferential measuring section. This data, combined with the surface indentation of the end-face measuring section and the vertical force of the bottom measuring section, forms a multi-dimensional data cross-validation, overcoming the limitations of traditional single-index measurements and providing a more comprehensive reflection of the internal density distribution of the track bed. The lateral compressive force data is synchronously transmitted to the data processing module 700 along with data from other measuring sections. Through a preset mapping relationship, the track bed density is calculated. Combined with the comprehensive analysis of multi-dimensional data, outliers can be effectively eliminated, making the final density determination more accurate and reliable, providing precise data for track maintenance.

[0098] Figure 21 shows the deformation of a ring of the strain resistance wire 321 in the circumferential measuring section. After the multi-dimensional measuring unit 300 is inserted into the ballast, the circumferential measuring section is subjected to the action of the compressive force. Due to the complexity of the interaction between the forces between the ballasts, the outer shell to which the strain resistance wire 321 is attached is subjected to uneven force, resulting in uneven deformation of the strain resistance wire 321, as shown in Figure 21(b).

[0099] When the circumferential measuring part of the multi-dimensional measuring unit 300 is subjected to circumferential force, the net external force is zero. Under uniform force distribution, the force at each point is uniform (Figure 21(a)); when the force distribution is non-uniform, the local force difference may be large, but the total effect is equivalent to that of uniform force distribution.

[0100] The mapping relationship between the compressive force q and the change in the inner circumference of the resistance wire ΔC was obtained by combining finite element simulation and experiment, i.e., q = T(ΔC). In this mapping relationship, q reflects the compaction of the track bed, while ΔC is reflected by the current value of the measuring module.

[0101] Since the influence of non-uniform forces is small and negligible, the contribution of local differences to the overall average force is negligible, and the final average force is consistent with that of uniformly distributed forces. That is, as shown in Figure 21. , The average value of the uniformly distributed force in Figure 21(a) is... This represents the average value of the non-uniform forces in Figure 21(b). (Used as q, not F)

[0102] When the strain resistance wire 321 is compressed by the circumferential compressive force along the axis of the multi-dimensional measuring unit 300, the strain resistance wire 321 undergoes a length change, and the amount of length change... It is directly proportional to the extrusion pressure, and the relationship is as follows:

[0103]

[0104] The change in length of strain gauge wire 321 under the same average force The change is determined by the average force and is independent of whether the force distribution is uniform. Therefore, the strain resistance wire 321 in Figures 21(a) and 21(b) has the same change.

[0105] The strain resistance wire 321 inside the circumferential measuring part has a multi-turn tower-shaped spiral structure. The direction and magnitude of the force on each ring of the resistance wire are different. However, since the strain resistance wire 321 inside the circumferential measuring part is a whole, the forces between the rings affect each other. Therefore, the final length change of the strain resistance wire 321 is the same and is not affected.

[0106] Axial stress for:

[0107] (1)

[0108] In the formula, A2 represents the effective cross-sectional area of ​​the circumferential detection module;

[0109] —The average value of the compressive force exerted by the circumferential detection module on the ballast in the normal direction;

[0110] —Radius of the circumferential detection module;

[0111] — Wall thickness of the circumferential detection module of the detection unit (non-rubber part).

[0112] Circumferential stress for:

[0113] (2)

[0114] Axial stress can also be calculated using the elastic modulus and axial strain of the material in the multi-dimensional measurement unit 300, as shown in equation (3); circumferential stress is obtained through circumferential strain, as shown in equation (4).

[0115] (3)

[0116] (4)

[0117] In the formula, —Axial strain;

[0118] —Circumferential strain;

[0119] E – Elastic modulus of the detection unit.

[0120] Strain measured by strain gauge wire 321 The sum of axial strain and circumferential strain is given by equation (5):

[0121] (5)

[0122] When the multi-dimensional measurement unit 300 has no opening in the middle, the cross-sectional area is... for:

[0123] (6)

[0124] After the multi-dimensional measurement unit 300 has an opening in the middle, the effective bearing area in the middle is reduced, resulting in a decrease in cross-sectional area. for:

[0125] (7)

[0126] Effective bearing area for:

[0127] (8)

[0128] According to equations (7) and (8), the effective bearing area is obtained. for:

[0129] (9)

[0130] According to equations (1) to (5) and equation (9), the middle extrusion pressure is obtained as follows:

[0131] (10)

[0132] The axial strain is:

[0133] (11)

[0134] The circumferential strain is:

[0135] (12)

[0136] After the multi-dimensional measurement unit 300 is completely submerged in the ballast, the pressure P2 on the track bed at the central location is:

[0137] (13)

[0138] Combining equations (10) and (13), we get:

[0139] (14)

[0140] As a preferred embodiment of the present invention, as shown in Figures 12, 18, and 19, the bottom measuring part includes a measuring probe 324 movably connected to the lower end of the lower assembly part 309. A second pressure sensor 323 is installed inside the lower assembly part 309 and above the measuring probe 324. Specifically, a connecting post 325 is constructed at the upper end of the measuring probe 324, an anti-loosening mounting slide 326 is constructed on the outer peripheral surface of the connecting post 325, a ball bearing 327 is installed in the anti-loosening mounting slide 326, and an assembly hole 328 is opened on the lower assembly part 309, in which the ball bearing 327 is engaged.

[0141] In this embodiment, the measuring probe 324 is in direct contact with the ballast. When it probes vertically downwards, the reaction force of the ballast is directly transmitted to the second pressure sensor 323 through the measuring probe 324 and the connecting post 325. This short force transmission path and low loss allow for accurate capture of vertical pressure data. This pressure value is positively correlated with the track bed density, providing the most direct core data for density calculation and avoiding errors caused by indirect measurements. The connection post 325 and the lower assembly 309 have a simple fit structure with no redundant transmission parts, reducing interference from mechanical friction, deformation, and other factors on the pressure signal. This ensures that the measurement value of the second pressure sensor 323 accurately reflects the vertical force of the ballast on the probe, improving data reliability. The measuring probe 324 directly contacts the ballast. Its shape (usually conical or arc-shaped) facilitates insertion into the ballast, reducing obstruction from ballast particles and ensuring the probe can penetrate to a predetermined depth to obtain vertical pressure data. This avoids the biased results caused by measuring only the surface ballast. The second pressure sensor 323 is installed inside the lower assembly 309, avoiding direct contact with the ballast and dust, reducing wear and contamination risks, and extending sensor lifespan. The mating structure of the connecting column 325 and the ball bearing 327 is wear-resistant and impact-resistant, capable of withstanding long-term repeated lowering and retraction movements, and adaptable to the needs of large-scale continuous inspection operations.

[0142] In this embodiment, the bottom measuring unit specifically detects the vertical reaction force of the ballast on the probe. Together with the surface indentation of the end-face measuring unit and the lateral compressive force of the circumferential measuring unit, it forms a three-dimensional data support, comprehensively reflecting the track bed density distribution from different force dimensions, thus overcoming the limitations of traditional single-index measurements. Vertical pressure data is synchronously transmitted to the data processing module 700 along with data from other measuring units. Through multi-dimensional data cross-validation, outliers (such as data distortion caused by excessively large local ballast particles) can be effectively eliminated, making the final density assessment more comprehensive and accurate, providing precise data for track maintenance.

[0143] The value measured by the second pressure sensor 323 at the bottom measuring section is F1, and the force consumed by the rubber ring is F. 1XJ The frictional resistance provided by the ballast to the end module is F. 1Z .

[0144] Since the outer shell of the multi-dimensional measurement unit 300 is made of the same material, the force consumed during the transmission of force in the end face measurement section and the circumferential measurement section of the track bed is negligible. During the insertion process, the time of collision with the top surface ballast of the track bed is extremely short, and the displacement of the top surface ballast of the track bed is small, making the contribution of force F0 to the momentum change negligible.

[0145] The ballast stiffness is denoted as k. After the bottom measuring part is submerged in the ballast, the frictional resistance is:

[0146] (15)

[0147] In the formula, F 1Z —The ballast provides frictional resistance to the bottom measuring section;

[0148] k — Ballast stiffness;

[0149] h1 — Height of the end module.

[0150] (16)

[0151] In the formula, F0 is the static pressure of the detection unit;

[0152] F 1XJ —The force consumed by the rubber ring;

[0153] F1 – The force measured by the pressure sensor.

[0154] The force F consumed by the rubber ring is obtained from equations (15) and (16). 1XJ for:

[0155] (17)

[0156] The pressure P1 on the bottom measuring part is:

[0157] (18)

[0158] The material and shape of ballast will affect its porosity. It is recommended to use hard rocks such as granite and basalt, and to avoid using needle-shaped and flaky ballast as much as possible. Given the differences in density between different ballast materials, the data obtained through experiments in this paper need to be adjusted for parameters of different ballast materials.

[0159] The density of the track bed before tamping is recorded as m0 (known and can be determined experimentally); the density of the track bed after vibration and dynamic stabilization is recorded as m1 (empirical value, known).

[0160] Before ballast compaction, the porosity of the ballast is e0 (which can be obtained experimentally), and the pressure at this point is denoted as P. e0 The porosity e1 of the ballast after vibration and dynamic stabilization is given by equation (19), and the pressure at this time is denoted as P. e1 .

[0161] (19)

[0162] The required pressure to increase the porosity of ballast from e0 to e1 for:

[0163] (20)

[0164] It can be obtained through experiments. The mapping relationship between e0 and e1.

[0165] Before the insertion of the multi-dimensional measurement unit 300, the compaction of the track bed was recorded as m. J0 (As is known, and can be determined experimentally), the porosity at this point is denoted as e. J0 (This can be obtained experimentally), pressure is denoted as P. J0 After the track bed was inserted 300 times by a multi-dimensional measurement unit, the compaction of the lower track bed was m. J1 (Unknown), porosity denoted as e J1 The pressure is P1; the compaction of the middle track bed is m. J2 (Unknown), porosity denoted as e J2 The pressure is P2; the density of the upper track bed is m. J3 (Unknown), porosity denoted as e J3 The pressure is P3.

[0166] (twenty one)

[0167] (twenty two)

[0168] (twenty three)

[0169] According to formula (20) The mapping relationship between e0 and e1 can be used to obtain the pressure P1 and e J0 e J1 The mapping relationship between P2 and e (Equation 24) J0 e J2 The mapping relationship between them (Equation 25), P3 and e J0 e J2 The mapping relationship between them (Equation 26).

[0170] (twenty four)

[0171] (25)

[0172] (26)

[0173] Based on this, we can then determine the change in density before and after the probe unit is inserted.

[0174] The density m measured by the multi-dimensional measurement unit 300 J1 m J2 m J3The density of the track bed on both sides of the left rail 800 at this location can be judged according to a certain ratio, which can be determined experimentally. Since the device measures the density of the two rails 800, the final density of the entire track bed at this location is the average of the density of the track bed on both sides of the left and right rails 800.

[0175] As a preferred embodiment of the present invention, as shown in Figures 10, 11, and 17, the safety protection unit includes a limiting sleeve 329 fitted outside the measuring component. The limiting sleeve 329 is connected to the cylinder rod 333 of the vertical drive unit. A limiting ring 330 is coaxially arranged inside the limiting sleeve 329. The limiting ring 330 is connected to the cylinder body 302 of the vertical drive unit through two limiting columns 331. A normally closed on / off switch 332 is installed on the limiting ring 330 and the connecting plate 304, respectively.

[0176] This embodiment's safety protection unit provides comprehensive safety assurance for the measuring component through its design of limit isolation, on / off linkage, and dual-scenario protection. The safety protection unit adapts to two hazardous operating conditions of the measuring component and the sleeper 900. When the limit sleeve 329 contacts the upper surface (Figure 22) or side (Figure 23) of the sleeper 900, it immediately triggers the corresponding normally closed on / off switch 332. The data processing module 700 quickly issues a retraction command to the vertical drive unit, preventing collisions and damage to precision components such as the measuring probe 324 and strain gauge wire 321 with the sleeper 900, thus solving the problem of densely distributed sleepers 900 in the track environment and the risk of accidental collisions. When the measuring component is within the safe zone of the sleeper 900 (Figure 24), the limit sleeve 329 and the limit ring 330 work together to maintain the on / off switch in a preset state, without affecting the normal downward probe of the measuring component, achieving a synergy between safety protection without interfering with measurement and measurement operations without neglecting safety.

[0177] In this embodiment, the limiting sleeve 329 moves synchronously with the cylinder rod 333, and the limiting ring 330 is fixed to the cylinder body 302 by the limiting column 331, forming a relatively stable protective structure. The mechanical contact during a collision is directly converted into a circuit signal for the normally closed on / off switch 332, eliminating the need for complex detection logic and providing a delay-free response. This is more reliable than pure software positioning protection, avoiding safety hazards caused by signal delays or misjudgments. The limiting sleeve 329, fitted onto the outside of the measuring component, not only triggers the protective command but also blocks ballast particles from directly impacting the measuring component through its own structure. Simultaneously, it acts as a buffer in case of accidental contact, reducing damage to the measuring component from the impact force.

[0178] After the protective action is triggered in this embodiment, the vertical drive unit retracts and reassesses the position of the sleeper 900. Combined with the real-time scanning data from the lidar scanner 500, the data processing module 700 can quickly determine new effective detection points without stopping the machine for troubleshooting, ensuring uninterrupted continuous operation while moving and measuring, balancing safety and detection efficiency. The packaged design of the limit sleeve 329 and the measuring components does not affect the downward travel of the vertical drive unit or the multi-dimensional detection action of the measuring components, adapting to the dynamic detection needs during equipment movement and avoiding the protective structure limiting the flexibility of equipment operation. The limit ring 330 and the limit column 331 adopt a rigid connection, which can resist vibration and bumps during track operation and avoid false triggering caused by the offset of the protective structure itself; the normally closed on / off switch 332 is installed between the limit ring 330 and the connecting plate 304, away from ballast dust and rainwater, reducing the impact of environmental factors on the reliability of the switch. Each component of the safety protection unit is assembled independently. Vulnerable parts such as the limit sleeve 329 and the normally closed on / off switch 332 can be disassembled and replaced separately, eliminating the need to disassemble the entire measuring actuator, reducing maintenance costs and downtime, and ensuring long-term stable operation of the equipment.

[0179] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A railway ballast bed compaction detection device, characterized in that: The system includes a track-moving mechanism, a reciprocating travel mechanism mounted on the track-moving mechanism, a positioning and scanning module and a measurement execution mechanism mounted on the reciprocating travel mechanism, the measurement execution mechanism including multiple multi-dimensional measurement units, each of which is actively inserted into a ballast bed, and a data processing module mounted on the reciprocating travel mechanism. The track-moving mechanism, the reciprocating travel mechanism, the positioning and scanning module, and the measurement execution mechanism are all connected to the data processing module. Each multi-dimensional measurement unit includes a connecting part mounted on the reciprocating travel mechanism. A vertical drive unit is installed at the lower end of the connecting part. The drive end of the vertical drive unit is connected to a measuring component via an adapter pipe. A connecting plate is connected between the drive end of the vertical drive unit and the adapter pipe. A first pressure sensor is installed between the connecting plate and the adapter pipe. A safety protection unit is fitted around the measuring component. The measuring component includes an end face measuring part, a circumferential measuring part, and a bottom measuring part, which are installed vertically downwards on the probe body. The upper end of the probe body is installed at the lower end of the adapter pipe. An upper assembly part and a middle assembly part are constructed vertically downwards on the probe body. The assembly section and lower assembly section are respectively equipped with the end face measuring section, circumferential measuring section, and bottom measuring section, which are assembled one-to-one with the upper assembly section, middle assembly section, and lower assembly section. The end face measuring section includes a protective cover fitted over the upper assembly section, a measuring disc movably fitted under the lower part of the upper assembly section, and a compression spring between the measuring disc and the protective cover, the compression spring being fitted over the upper assembly section. An assembly opening is provided on the peripheral wall of the upper assembly section, and ceramic positioning seats are respectively assembled at the upper and lower ends of the assembly opening. A rod-shaped resistance wire and a resistance slide rail are installed side by side between the two ceramic positioning seats. A sliding overcurrent bridge is slidably connected between the rod-shaped resistance wire and the unobstructed slide rail, and the overcurrent bridge is connected to the measuring disc; the circumferential measuring part includes a conical elastic shell installed in the middle assembly part, and a strain resistance wire in a conical spiral shape is coaxially arranged in the conical elastic shell. The shape of the middle assembly part is the same as that of the conical elastic shell. Multiple strip holes are spaced apart on the peripheral wall of the middle assembly part, and each strip hole extends vertically. A rubber sealing gasket is provided between the middle assembly part and the conical elastic shell, and the rubber sealing gasket extends out of the strip hole at the position of the strip hole.

2. The railway ballast bed compaction detection equipment according to claim 1, characterized in that: The track mechanism includes a frame mounted above the track, with a passive wheel set and a driving wheel set installed at the front and rear ends of the lower end of the frame, respectively. Both the passive wheel set and the driving wheel set run on the two steel rails of the track. A vehicle speed sensing module is installed on the frame, located at the driving wheel set.

3. The railway ballast bed compaction detection equipment according to claim 1, characterized in that: The reciprocating travel mechanism includes a mounting plate that is slidably mounted on the track mechanism along the length direction of the track mechanism. A drive assembly is mounted on the lower end of the mounting plate. The drive assembly is connected to the track mechanism in a transmission manner, and the mounting plate can move along the length direction of the track mechanism under the drive of the drive assembly.

4. The railway ballast bed compaction detection equipment according to claim 1, characterized in that: The positioning and scanning module includes a Beidou positioning system and two LiDAR scanners installed on the reciprocating walking mechanism. The two LiDAR scanners are located on both sides of the reciprocating walking mechanism. The Beidou positioning system and the two LiDAR scanners are all connected to the data processing module.

5. The railway ballast bed compaction detection equipment according to claim 1, characterized in that: The bottom measuring part includes a measuring probe movably connected to the lower end of the lower assembly part, and a second pressure sensor is installed inside the lower assembly part and at the upper end of the measuring probe.

6. The railway ballast bed compaction detection equipment according to claim 1, characterized in that: The safety protection unit includes a limiting sleeve fitted outside the measuring component and connected to the drive end of the vertical drive unit. A limiting ring is coaxially arranged inside the limiting sleeve. The limiting ring is connected to the body of the vertical drive unit through two limiting columns. Normally closed on / off switches are installed on the limiting ring and the connecting plate, respectively.

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