A device and method for detecting underground cavities

Abstract

This invention discloses an underground cavity exploration and detection device and method, belonging to the field of underground cavity detection technology. The device includes a vehicle body equipped with a seismic hammer, lateral and longitudinal detection components, a support component with a geophone, and a control module. The support component is telescopically adjustable, and the geophone is pressed against the ground by a spring. The method includes road surface clearing, vehicle positioning and automatic leveling calibration, seismic hammer impact to generate seismic waves, geophone receiving the seismic waves and converting them into electrical signals, control module processing data, equipment retrieval, and multi-point repeated detection. This invention achieves automatic leveling and adjustment, improving detection accuracy; ensures stable reception of seismic wave signals, reducing attenuation interference; and automated operation reduces manpower and errors, meeting the needs of large-area rapid exploration, and is suitable for hazard investigation in urban roads and other areas.

Description

Technical Field

[0001] This invention belongs to the field of underground cavity detection technology, specifically relating to an underground cavity exploration and detection device and method. Background Technology

[0002] Underground cavities, such as those formed by aging and damaged underground pipelines, roadbed voids, and karst cavities, pose significant hidden dangers to the safe operation of urban roads, municipal pipelines, and major transportation infrastructure. They can easily lead to accidents such as road collapses and pipeline ruptures, seriously threatening the safety of people and property. Therefore, accurate and efficient underground cavity investigation and detection is a core component of infrastructure operation and maintenance and hazard identification.

[0003] Current underground cavity detection technologies mainly rely on methods such as seismic wave detection and radar detection. Among these, seismic wave detection is widely used due to its low cost and high sensitivity to deep cavities. However, existing seismic wave detection equipment still has the following shortcomings:

[0004] 1. Existing equipment relies heavily on manual observation of the level for calibration, making it difficult to achieve simultaneous and accurate judgment of the horizontal and vertical directions. The tilt of the vehicle body will cause the impact point of the seismic source to shift and the receiving angle of the detector to deviate, directly affecting the propagation path of the seismic wave and the accuracy of signal acquisition, thereby reducing the accuracy of cavity location and size determination.

[0005] 2. From equipment positioning, horizontal calibration, seismic source activation to detector retrieval, manual operation is required step by step. This not only consumes a lot of manpower and time, but also easily leads to poor data consistency at different detection points due to human operation errors such as calibration timing and hammering duration control, making it difficult to meet the needs of rapid exploration of large areas and multiple points. Summary of the Invention

[0006] To address the problems existing in the above-mentioned prior art, a device and method for underground cavity exploration and detection are proposed.

[0007] The technical solution to the technical problem solved by the present invention is as follows: On the one hand, an underground cavity exploration and detection device is proposed, including a vehicle body, wheels are provided at the bottom of the vehicle body, and a seismic source hammer capable of vertically impacting the road surface is provided inside the vehicle body; two sets of detection components are provided at the top of the vehicle body, which are arranged horizontally and vertically respectively, so as to detect whether the vehicle body is in a horizontal state; several sets of support components are also provided around the vehicle body, and detectors are provided at the bottom of the support components. The probes of the detectors can extend out of the support components and couple with the ground to detect the road surface seismic wave situation.

[0008] Preferably, the detection assembly includes two brackets, with a stop bar rotatably connected between the two brackets, and an infrared sensor is provided between the two brackets. The infrared sensor includes a transmitter and a receiver. The transmitter is mounted on one bracket, and the receiver is mounted on the other bracket. The infrared transmitter and the infrared receiver are arranged facing each other so that the infrared rays emitted by the transmitter can be received by the receiver. When the stop bar is rotated to a vertical position, the lower end of the stop bar can block the receiver and the transmitter, thereby blocking the reception.

[0009] Preferably, there are two sets of infrared sensors, which are arranged in parallel on both sides of the bracket; the middle of the baffle is hollowed out so that two vertical plates are formed on both sides of the baffle, and the two vertical plates can block the two infrared sensors respectively. When the two vertical plates block the infrared sensors at the same time, the device is in a horizontal state in that direction.

[0010] Preferably, the support assembly includes a boss fixed to the side of the vehicle body; a spline shaft is rotatably connected to the bottom of the boss, and the spline shaft is driven to rotate by a telescopic motor fixed to the boss; a spline sleeve is fitted over the spline shaft, and an external thread is opened on the outer side of the spline sleeve, and a fixing seat is connected to the corresponding thread on the outer side of the spline sleeve, and the fixing seat is fixed to the bottom of the boss; a first sliding sleeve is vertically slidably connected to the fixing seat, and the bottom of the spline sleeve is rotatably connected to the bottom of the first sliding sleeve; a second sliding sleeve is vertically slidably connected to the outside of the first sliding sleeve; a vertically threaded hole is also opened inside the spline shaft, and a threaded rod is threadedly connected inside the vertically threaded hole, and the bottom of the threaded rod passes through the spline sleeve and the first sliding sleeve and is rotatably connected to the bottom of the second sliding sleeve.

[0011] Preferably, a first guide block is connected to the outer wall of the fixed base, and a first guide groove is opened on the inner wall of the first sliding sleeve. The first guide block can slide along the first guide groove to realize the vertical sliding of the first sliding sleeve along the fixed base; a second guide block is connected to the outer wall of the first sliding sleeve, and a second guide groove is opened on the inner wall of the second sliding sleeve. The second guide block can slide along the first slide groove to realize the vertical movement of the second sliding sleeve along the first sliding sleeve.

[0012] Preferably, the bottom of the second sliding sleeve is provided with a vertical groove, and the detector can move vertically within the vertical groove. A spring is connected between the detector and the top of the groove, and the spring can press the probe at the bottom of the detector onto the road surface to detect seismic waves.

[0013] Preferably, the vibratory hammer is driven downward to strike the ground by a drive assembly. The drive assembly includes a housing, a vertically slidable vertical rod inside the housing, the bottom of the vertical rod connected to the vibratory hammer, a toothed groove on the vertical rod, and two rotating shafts on corresponding sides of the vertical rod, the rotating shafts being rotatably connected to the side wall of the housing. Each rotating shaft is connected to an incomplete gear, half of the incomplete gear has teeth and half has no teeth, the two incomplete gears can alternately engage with the toothed groove to push the vertical rod to move vertically. A driven gear is also connected to the rotating shaft, and a drive shaft is rotatably connected to the corresponding housing, the drive shaft is connected to a drive gear, the drive gear is positioned between the two driven gears and cooperates with the driven gears to drive their rotation, the drive shaft is driven to rotate by a drive motor fixed on the housing.

[0014] Preferably, a seismic source coupling plate is also provided at the bottom of the vehicle body. The seismic source coupling plate and the vehicle body are connected by an electromagnet. The electromagnet is fixed to the vehicle body, but when the electromagnet is de-energized, the seismic source coupling plate falls to the road surface, pushing the vehicle body to move the seismic source hammer to the bottom of the seismic source coupling plate and press down on the seismic source coupling plate, thereby increasing the seismic wave.

[0015] Preferably, the vehicle body is also equipped with a control module, which is electrically connected to the detection component, the support component, and the drive component. The control module can receive electrical signals emitted by the detection component and drive the support component to extend and retract for support, and finally drive the drive component to strike the ground to generate seismic waves.

[0016] On the other hand, a detection method using the aforementioned underground cavity exploration and detection equipment is proposed, comprising the following steps:

[0017] S1. Road surface clearing; determine the survey route and detection points of the road surface to be detected, clear obstacles around the points, ensure that the vehicle can be parked smoothly, and that there are no debris that may affect the transmission of seismic waves or the coupling of the detector.

[0018] S2. Vehicle positioning and leveling calibration;

[0019] S2.1 Point Docking: Move the equipment to the first detection point using the wheels at the bottom of the vehicle, align the center of the vehicle with the core area of ​​the point, stop the vehicle and lock the wheels;

[0020] S2.2 Horizontal adjustment; The control module sends commands to the support components around the vehicle body to start the telescopic motors of the support components and drive the spline shaft to rotate; so that the support components support the ground and the detector probe touches the ground;

[0021] S2.3 Horizontal Detection: The control module activates two sets of detection components, and the infrared sensors of each set of components begin to work. If the stop lever is not rotated to the vertical position, the infrared light is normally received by the receiver, indicating that the equipment is not yet horizontal. If the stop lever is rotated to the vertical position, the vertical plates on both sides simultaneously block the two sets of infrared sensors, and the receiver receives no signal. The control module determines that the equipment is horizontal in that direction. If it is not horizontal, the support component on one side is driven to stabilize according to the tilt condition to adjust the vehicle body until both the horizontal and vertical detections show horizontality.

[0022] S3. Seismic waves generated by the source hammer: The control module starts the drive motor of the drive component, which drives the drive shaft to rotate, and the drive gear on the drive shaft rotates synchronously; the drive gear meshes with the driven gears on both sides, driving the rotating shaft and the incomplete gear on the rotating shaft to rotate; the two incomplete gears alternately engage with the tooth grooves of the vertical rod, pushing the vertical rod to move vertically repeatedly, so that the source hammer continuously strikes the ground, generating seismic waves for detection;

[0023] S4. Signal conversion: When seismic waves from beneath the ground propagate to different media, they are reflected and refracted. The detector receives these seismic waves and converts the mechanical seismic wave signals into electrical signals.

[0024] S5. Data transmission: The detector transmits the electrical signal to the control module in real time. The control module performs preliminary filtering and amplification on the signal, stores the original seismic wave data, and completes the detection data acquisition at the current point.

[0025] S6. Single-point recovery; After the data acquisition of the current point is completed, the control module first stops the drive motor to reset the vibratory source hammer; then drives the telescopic motor of the support component to reverse, driving the spline shaft, spline sleeve, and sliding sleeve to rise and retract the detector;

[0026] S7. Multiple-point repetition: Move the vehicle to the next detection point by using the wheels, repeating S1-S6 until all points in the area to be detected are surveyed.

[0027] Compared with existing technologies, the above technical solution has the following advantages or beneficial effects:

[0028] 1. This invention uses two sets of detection components arranged laterally and longitudinally to detect the horizontal state of the vehicle body in two vertical directions in real time. With the help of a telescopic and adjustable support component, it can automatically determine and adjust the horizontal state. Compared with manual calibration, this structure does not require manual intervention and can quickly ensure that the vehicle body is on a horizontal reference plane. It avoids the displacement of the seismic source and the deviation of the detector angle caused by the tilt of the vehicle body, and ensures the stability of the seismic wave propagation path from the source, thereby improving the accuracy of cavity location, depth and size determination.

[0029] 2. The multi-stage telescopic structure of the support components—spline shaft, spline sleeve, and double sliding sleeve—of this invention can adapt to road surfaces with varying degrees of undulation. Simultaneously, the detector is elastically connected to the second sliding sleeve via a spring. The preload of the spring tightly presses the detector probe against the ground, effectively eliminating the gap between the detector and the ground. This design not only allows for adjustment of the vehicle's horizontal position through the individual movement of the support components at different locations but also significantly reduces the attenuation and interference of seismic wave signals during transmission, ensuring the detector can stably receive weak seismic wave signals, especially those reflected from small-sized, shallow cavities, thus improving the signal-to-noise ratio and effectiveness of the detection data.

[0030] 3. This invention achieves automated control through a control module, eliminating the need for manual step-by-step operation. Operators only need to move the equipment to the detection point, and the subsequent process is automatically completed by the control module. This not only significantly reduces manpower and operation time but also ensures consistent operation standards across different detection points, avoiding data discrepancies caused by human error. It meets the needs of rapid surveying of large areas and multiple points, and is especially suitable for large-scale hazard investigation scenarios such as urban roads and industrial parks. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Figure 2 This is a schematic diagram of the bottom structure of the present invention.

[0034] Figure 3 This is a schematic diagram of the supporting component structure.

[0035] Figure 4 This is a schematic diagram of the detection component structure.

[0036] Figure 5 This is a cross-section of the driver component. Figure 1 .

[0037] Figure 6 This is a cross-section of the driver component. Figure 2 .

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Vehicle body; 11. Wheel; 12. Push rod; 13. Handle; 2. Vibration source hammer; 3. Detection assembly; 31. Bracket; 32. Stop bar; 33. Transmitter; 34. Receiver; 35. Vertical plate; 4. Support assembly; 41. Boss; 42. Splined shaft; 43. Telescopic motor; 44. Splined sleeve; 45. Fixing seat; 46. First sliding sleeve; 47. Second sliding sleeve; 48. Vertical threaded hole; 49. Threaded rod; 410. First guide 411. Guide groove; 412. First guide block; 413. Second guide groove; 414. Vertical slide; 415. Spring; 416. Detector; 417. Probe; 5. Control module; 6. Drive assembly; 61. Housing; 62. Vertical rod; 63. Gear; 64. Rotating shaft; 65. Incomplete gear; 66. Driven gear; 67. Drive shaft; 68. Drive gear; 69. Drive motor; 7. Vibration source coupling plate. Detailed Implementation

[0040] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and processes are omitted to avoid unnecessarily limiting the invention. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Example 1:

[0042] Please see Figures 1-6The underground cavity exploration and detection equipment uses vehicle body 1 as its core load-bearing structure. Vehicle body 1 is made of high-strength alloy material, which ensures structural stability while reducing overall weight for easy movement. Wheels 11 are symmetrically installed at the four corners of the bottom of vehicle body 1. The wheels 11 are made of non-slip rubber material and can be adapted to various road surfaces such as asphalt and cement.

[0043] A push rod 12 can be installed on the vehicle body 1, and a handle 13 is connected to the push rod 12 to facilitate pushing the vehicle body 1; a seismic source hammer 2 is fixedly installed in the middle of the inner cavity of the vehicle body 1, and a drive assembly 6 is connected above it. The drive assembly 6 can drive the seismic source hammer 2 to reciprocate vertically, thereby periodically impacting the road surface and transmitting seismic waves into the ground.

[0044] Two sets of detection components 3 are vertically intersecting on the top surface of the vehicle body 1. One set is arranged along the length direction (longitudinal) of the vehicle body 1, and the other set is arranged along the width direction (lateral) of the vehicle body 1. The two sets of components have completely identical structures and together constitute the horizontal detection system of the equipment, which is used to determine in real time whether the vehicle body 1 is in a horizontal state. The intersecting arrangement of the two sets of detection components 3 in the longitudinal and lateral directions can cover two vertical directions of the plane of the vehicle body 1, avoiding the blind spot in horizontal judgment caused by detection in a single direction, and laying the foundation for the subsequent stable impact of the vibrating hammer 2 and the accurate signal reception of the detector 416.

[0045] Support components 4 are evenly distributed around the vehicle body 1 (at least one set on each side, 4-6 sets in total). The support components 4 are fixedly connected to the side wall of the vehicle body 1 and can extend and retract vertically. A detector 416 can be detachably installed at the bottom of each support component 4. The detector 416 adopts a high-sensitivity piezoelectric sensor. Its probe 417 is wrapped with a wear-resistant rubber sleeve. When the support component 4 extends and retracts, it can push the detector 416 downward, so that the probe 417 extends out of the support component 4 and fits tightly (couples) with the ground, thereby accurately receiving the seismic wave signals reflected and refracted from the ground.

[0046] Example 2:

[0047] Continue reading Figures 1-6 Based on Embodiment 1, this embodiment proposes a detection component 3, which includes two symmetrically arranged brackets 31, which are welded to the top of the vehicle body 1 and fixed. Pin holes are provided on the opposite sides of the two brackets 31, and a stop bar 32 is rotatably connected to them through the pin. The stop bar 32 can rotate around the pin in the vertical plane (rotation angle range is 0-90°, 0° is the vertical state, and 90° is the horizontal state).

[0048] An infrared sensor is fixedly installed between the two brackets 31, below the stop bar 32. The infrared sensor consists of an independent transmitter 33 and a receiver 34. The transmitter 33 is fixed to the inner wall of one bracket 31 by a snap fastener, and the receiver 34 is fixed to the inner wall of the other bracket 31. The central axes of the transmitter 33 and the receiver 34 are completely coincident (opposite to each other), ensuring that the infrared rays emitted by the transmitter 33 can propagate in a straight line to the receiver 34.

[0049] When the stop lever 32 rotates around the pin to a vertical position, the lower end of the stop lever 32 will be exactly on the infrared propagation path between the transmitter 33 and the receiver 34, thus completely blocking the infrared light and preventing the receiver 34 from receiving the signal. When the stop lever 32 is not in a vertical position (tilted position), the infrared propagation path is unobstructed, and the receiver 34 can receive the signal normally. The levelness of the vehicle body 1 is determined by the simple logic of whether the infrared light is blocked. Compared with the traditional bubble level, this avoids the error of manual observation, and the signal can be directly transmitted to the control module 5 to achieve automated judgment.

[0050] Example 3:

[0051] Please see Figure 4 In order to reduce the possibility that the detection component 3 cannot detect due to the excessively small deflection angle caused by the thickness of the stop bar 32, in this embodiment, the infrared sensor is set as two sets. The two sets of infrared sensors are arranged in parallel along the height direction of the bracket 31 and are fixed between the two brackets 31. The transmitters 33 and receivers 34 of the two sets of sensors are respectively arranged opposite each other to form two parallel infrared propagation paths.

[0052] Correspondingly, the middle part of the stop bar 32 is hollowed out along the length direction (the width of the hollowed-out area matches the spacing of the infrared sensors), so that two independent vertical plates 35 are formed on both sides of the stop bar 32. The distance between the vertical plates 35 is consistent with the vertical spacing of the two sets of infrared sensors, and the two vertical plates 35 correspond to the infrared paths of the two sets of infrared sensors respectively.

[0053] When the stop lever 32 rotates to the vertical position, both vertical plates 35 simultaneously enter the propagation path of the two sets of infrared sensors, blocking two infrared rays respectively, preventing both sets of receivers 34 from receiving signals. If only one vertical plate 35 blocks the infrared ray (while the other receives normally), it is determined that the stop lever 32 is not completely vertical, and the device is not horizontal in that direction. This reduces the possibility of misjudgment when the stop lever 32 is slightly tilted but happens to block a single infrared ray, further improving the accuracy of horizontal detection.

[0054] Example 4:

[0055] Continue reading Figures 1-6In this embodiment, a support component 4 is provided as needed, including a boss 41 welded and fixed to the side wall of the vehicle body 1, which is used to bear the vertical load of the support component 4. A circular through hole is provided at the center of the bottom of the boss 41, and a spline shaft 42 is rotatably connected to the through hole through a bearing. The upper end of the spline shaft 42 extends above the boss 41 and is connected to the output shaft of the telescopic motor 43 fixed on the top of the boss 41 through a coupling. The telescopic motor 43 can drive the spline shaft 42 to rotate clockwise or counterclockwise around its own axis.

[0056] A matching spline sleeve 44 (with a spline groove in the inner hole adapted to the spline shaft 42) is fitted on the outer side of the spline shaft 42. The spline sleeve 44 can rotate synchronously with the spline shaft 42 and can slide vertically along the spline shaft 42. The outer wall of the spline sleeve 44 is machined with external threads. A fixing seat 45 is provided on the outer side of the spline sleeve 44. The fixing seat 45 is a cylindrical structure. The top is welded to the bottom of the boss 41. The inner hole of the fixing seat 45 is machined with internal threads adapted to the external threads of the spline sleeve 44. The spline sleeve 44 and the fixing seat 45 are connected by thread engagement.

[0057] A first sliding sleeve 46 is fitted on the outer side of the fixed base 45. The first sliding sleeve 46 has a cylindrical structure. A first guide block 411 is connected to the outer wall of the fixed base 45. A first guide groove 410 is opened on the inner wall of the first sliding sleeve 46. The first guide block 411 can slide along the first guide groove 410 to realize the vertical sliding of the first sliding sleeve 46 along the fixed base 45. The bottom of the spline sleeve 44 is rotatably connected to the bottom inner wall of the first sliding sleeve 46 through a bearing (when the spline sleeve 44 rotates, it does not drive the first sliding sleeve 46 to rotate, but only drives it to move vertically).

[0058] The outer wall of the first sliding sleeve 46 is fitted with a second sliding sleeve 47, which is also a cylindrical structure. A second guide block 413 is connected to the outer wall of the first sliding sleeve 46, and a second guide groove 412 is opened on the inner wall of the second sliding sleeve 47. The second guide block 413 can slide along the first sliding groove to realize the vertical movement of the second sliding sleeve 47 along the first sliding sleeve 46.

[0059] Furthermore, the splined shaft 42 has a vertical threaded hole 48 along its axis inside, and a threaded rod 49 is engaged within the threaded hole. The bottom of the threaded rod 49 passes sequentially through the central through hole of the splined sleeve 44 and the central through hole of the first sliding sleeve 46, and is rotatably connected to the bottom inner wall of the second sliding sleeve 47 via a bearing. When the splined shaft 42 rotates, the threaded rod 49 can move vertically along the threaded hole of the splined shaft 42, further pushing the second sliding sleeve 47 to slide along the first sliding sleeve 46. The precise fit between the guide block and the guide groove avoids the problem of jamming when the sliding sleeve slides, ensuring that the support assembly 4 can be raised and lowered smoothly when driven by the telescopic motor 43, thus improving the efficiency of horizontal adjustment.

[0060] Example 5:

[0061] Continue reading Figures 1-6 To improve the coupling effect between the detector 416 and the ground, this embodiment designs the installation structure of the detector 416. A vertical groove 414 (the groove is a cylindrical hole with a diameter slightly larger than the diameter of the detector 416 shell) is provided at the bottom center of the second sliding sleeve 47. The shell of the detector 416 is fitted with the inner wall of the vertical groove 414 with a clearance, and the detector 416 can move freely vertically along the vertical groove 414.

[0062] A spring 415 is connected between the top of the detector 416 and the top inner wall of the vertical slide 414. The spring 415 is a compression spring. When the spring 415 is in its natural state, the probe 417 of the detector 416 can extend out of the bottom of the second slide sleeve 47. When the support assembly 4 descends and the probe 417 of the detector 416 contacts the ground, the second slide sleeve 47 continues to descend and compresses the spring 415. The elastic force generated by the spring 415 presses the probe 417 at the bottom of the detector 416 tightly onto the road surface, realizing the tight coupling between the detector 416 and the ground.

[0063] In addition, a rubber sealing ring is provided between the detector 416 and the vertical slide 414 to prevent dust and rainwater from entering the slide and affecting the movement and service life of the detector 416.

[0064] Example 6:

[0065] Continue reading Figures 1-6 Based on the above embodiments, this embodiment proposes a driving assembly 6 for driving the vertical movement of the vibratory source hammer 2, including a housing 61 fixed to the top of the inner cavity of the vehicle body 1 to protect the internal components. A vertical rod 62 is provided in the inner cavity of the housing 61, and the outer wall of the vertical rod 62 is clearance-fitted with the inner wall of the housing 61, allowing it to slide freely vertically along the inner cavity of the housing 61. The bottom of the vertical rod 62 extends out of the bottom of the housing 61 and is fixedly connected to the top of the vibratory source hammer 2 by bolts. A toothed groove 63 is evenly provided on one side wall of the vertical rod 62 along the length direction. Two rotating shafts 64 are symmetrically arranged on both sides of the vertical rod 62 corresponding to the tooth groove 63. The two ends of the rotating shafts 64 are rotatably connected to the two side walls of the housing 61 through bearings. The rotating shafts 64 can rotate freely around their own axis. Each rotating shaft 64 is connected to an incomplete gear 65 through a flat key. Only 1 / 2 area of ​​the circumference of the incomplete gear 65 is machined with teeth. The tooth parameters are adapted to the tooth groove 63 of the vertical rod 62. The tooth areas of the two incomplete gears 65 are staggered. That is, when the teeth of one incomplete gear 65 are engaged in the tooth groove 63, the toothless area of ​​the other incomplete gear 65 corresponds to the tooth groove 63. They can be alternately engaged in the tooth groove 63 of the vertical rod 62, pushing the vertical rod 62 to move back and forth vertically.

[0066] Each rotating shaft 64 is also connected to a driven gear 66 via a key. The driven gear 66 is located outside the incomplete gear 65 and rotates coaxially with the rotating shaft 64. A drive shaft 67 is rotatably connected to the inner wall of the housing 61 via a bearing. The drive shaft 67 is parallel to the rotating shaft 64, and a drive gear 68 is connected to the drive shaft 67 via a key. The tooth parameters of the drive gear 68 are matched with those of the driven gear 66. The drive gear 68 is positioned between the two driven gears 66 and meshes with both driven gears 66 simultaneously, driving the two driven gears 66 to rotate synchronously. One end of the drive shaft 67 extends out of the housing 61 and is connected to the output shaft of the drive motor 69 fixed to the side wall of the housing 61 via a coupling. The drive motor 69 can drive the drive shaft 67 to rotate forward.

[0067] Two incomplete gears 65 alternately engage with the tooth grooves 63, which can drive the vertical rod 62 to reciprocate continuously, so that the seismic source hammer 2 strikes the ground at a fixed frequency (controlled by the speed of the drive motor 69), avoiding the problem of unstable seismic wave intensity caused by a single impact, and ensuring that the medium at different depths underground can receive uniform seismic wave signals.

[0068] Example 7:

[0069] Continue reading Figures 1-6 To enhance the shock wave transmission effect, a shock source coupling plate 7 can be installed directly below the shock source hammer 2. The area of ​​the coupling plate is larger than the bottom area of ​​the shock source hammer 2, which can increase the shock contact area.

[0070] The source coupling plate 7 is connected to the bottom of the vehicle body 1 by an electromagnet. The top of the electromagnet is fixed to the bottom of the vehicle body 1 by bolts, and the bottom of the electromagnet is attracted to the top surface of the source coupling plate 7. When the electromagnet is energized, it generates magnetic force to attract and fix the coupling plate. When the power is off, the magnetic force disappears and the coupling plate can fall freely.

[0071] In use, first align the seismic source coupling plate 7 at the bottom of the vehicle body 1 with the detection point, then turn off the electromagnet and control the electromagnet to de-energize. The seismic source coupling plate 7 falls onto the road surface under its own gravity and adheres to the ground. Then, push the vehicle body 1 to move the seismic source hammer 2 above the seismic source coupling plate 7. The drive component 6 drives the seismic source hammer 2 to move downward. After the bottom of the seismic source hammer 2 contacts the top of the seismic source coupling plate 7, it continues to press down. The shock force is evenly transmitted to the ground through the coupling plate, increasing the propagation range and intensity of the seismic wave.

[0072] Example 8:

[0073] Continue reading Figures 1-6Based on the above embodiments, a control module 5 (the control module 5 is an integrated industrial control box with a built-in PLC controller, signal acquisition card, data storage module and wireless communication module) is fixedly installed on the operating platform on the top of the vehicle body 1. The control module 5 is electrically connected to the detection component 3, support component 4, drive component 6 and detector 416 through wires to form a complete electrical control circuit.

[0074] The working logic of control module 5 is as follows:

[0075] Signal reception: Real-time reception of infrared sensor signals from detection component 3 (to determine horizontal status) and seismic electrical signals from detector 416 (to collect detection data);

[0076] Command output: Based on the infrared sensor signal, output commands to drive the telescopic motor 43 of the support component 4 to rotate forward / reverse and adjust the vehicle body 1 to be level; based on the detection requirements, output commands to control the drive motor 69 to start / stop and the electromagnet to be energized / de-energized.

[0077] Data processing: Performs preliminary processing (filtering and amplification) on the electrical signal transmitted by detector 416, and stores the raw data through the data storage module. At the same time, it can transmit the data to an external terminal (such as a computer or tablet) through the wireless communication module.

[0078] The control module 5 can automatically complete horizontal detection, support adjustment, seismic source drive and data acquisition without manual operation by staff, reducing human error (such as deviation in manual judgment of horizontal status) and improving detection efficiency.

[0079] The testing method for this device is as follows:

[0080] S1: Road cleaning

[0081] First, the survey route and detection points of the road surface to be detected are determined through on-site survey; staff are arranged to use brooms, shovels and other tools to clear obstacles (such as stones, bricks, branches, fallen leaves, etc.) within 1-2 meters around each detection point to ensure that vehicle 1 can be parked smoothly at the point and that there are no debris that affect the vibration action of the seismic source hammer 2 or the coupling between the detector 416 and the ground.

[0082] S2: Vehicle body positioning and leveling calibration:

[0083] S2.1 Point docking: The staff controls the wheels 11 to rotate through the control handle (or remote control) of the vehicle body 1, moving the equipment to the first detection point. The center of the vehicle body 1 is aligned with the core area of ​​the point by the positioning mark (such as the center red line) on the top of the vehicle body 1, and the alignment error does not exceed 5cm.

[0084] S2.2 Horizontal Adjustment: The staff sends a horizontal adjustment command through the touch screen of the control module 5. The control module 5 sends a signal to the support components 4 around the vehicle body 1 to start the telescopic motor 43 of the support components 4. The telescopic motor 43 drives the spline shaft 42 to rotate forward, which drives the spline sleeve 44 to move downward along the internal thread of the fixed seat 45, thereby pushing the first sliding sleeve 46 and the second sliding sleeve 47 to descend synchronously, so that the probe 417 of the detector 416 touches the ground. At this time, the support components 4 initially support the vehicle body 1, and the wheels 11 are still in contact with the ground (not completely off the ground).

[0085] S2.3 Horizontal Detection: The control module 5 automatically activates two sets of detection components 3 (horizontal and longitudinal). The infrared sensors of each set of detection components 3 start working (the transmitter 33 emits infrared rays, and the receiver 34 receives them in real time). If the stop lever 32 is not rotated to the vertical position (the vehicle body 1 is tilted), the infrared rays are unobstructed, the receiver 34 continues to receive signals, the control module 5 determines that the equipment is not yet horizontal, and displays the tilt direction (such as "longitudinal left low") to the outside world through the control module 5. If the stop lever 32 is rotated to the vertical position, the vertical plates 35 on both sides simultaneously block the two sets of infrared sensors, the receiver 34 has no signal, and the control module 5 determines that the equipment is horizontal in this direction. If it is not horizontal, the control module 5 drives the corresponding support component 4 to continue to extend and retract according to the tilt direction (such as driving the left support component 4 to descend and the right support component 4 to rise if the left side is low), and repeatedly adjusts until both the horizontal and longitudinal detection components 3 display "horizontal". At this time, the wheels 11 are completely off the ground, and the vehicle body 1 is only supported by the support components 4.

[0086] S3: Seismic waves are generated by the focal hammer 2.

[0087] After the horizontal calibration is completed, the control module 5 automatically starts the drive motor 69 of the drive assembly 6. The drive motor 69 drives the drive shaft 67 to rotate, and the drive gear 68 on the drive shaft 67 rotates synchronously. The drive gear 68 meshes with the driven gears 66 on both sides, driving the two rotating shafts 64 and the incomplete gears 65 on the rotating shafts 64 to rotate synchronously.

[0088] The tooth regions of the two incomplete gears 65 alternately engage with the tooth grooves 63 of the vertical rod 62: when the tooth of the left incomplete gear 65 engages with the tooth groove 63, it pushes the vertical rod 62 upward, causing the seismic source hammer 2 to rise; when the tooth of the right incomplete gear 65 engages with the tooth groove 63, it pushes the vertical rod 62 downward, causing the seismic source hammer 2 to strike the ground (or the seismic source coupling plate 7) downward; through the continuous rotation of the incomplete gears 65, the vertical rod 62 moves vertically repeatedly, causing the seismic source hammer 2 to continuously strike the ground at a fixed frequency, generating stable seismic waves.

[0089] S4: Signal Conversion

[0090] The seismic waves generated by the source hammer 2 propagate underground. When they encounter underground cavities (or interfaces between different media, such as soil and rock, or cavities and soil), they are reflected and refracted, forming reflected waves and refracted waves. The detectors 416 around the vehicle body 1 receive these seismic waves returning to the ground in real time. The piezoelectric element inside the detector 416 converts the mechanical seismic wave signal into a corresponding electrical signal (the intensity of the electrical signal is positively correlated with the intensity of the seismic wave).

[0091] S5: Data Transmission

[0092] The detector 416 transmits the converted electrical signal to the control module 5 in real time via a wire (or wirelessly). The signal processing module built into the control module 5 performs preliminary processing on the electrical signal: first, it removes noise (such as noise generated by environmental vibration) from the electrical signal through a filtering circuit, then it amplifies the weak signal through an amplification circuit, and finally it stores the processed original seismic wave data in the data storage module to complete the acquisition of detection data at the current point.

[0093] S6: Single-point recovery

[0094] After the data acquisition at the current location is completed, the control module 5 first stops the drive motor 69, causing the vertical rod 62 to drive the vibratory source hammer 2 to reset to the initial position; then the control module 5 drives the telescopic motor 43 of the support assembly 4 to reverse, causing the spline shaft 42 and spline sleeve 44 to move upward along the internal thread of the fixed seat 45, thereby pulling the first sliding sleeve 46 and the second sliding sleeve 47 to rise. The detector 416 rises with the second sliding sleeve 47, and the probe 417 leaves the ground and retracts into the vertical groove 414 of the second sliding sleeve 47; ready to move to the next location.

[0095] S7: Multiple repetitions

[0096] The staff controls the wheels 11 to rotate, moving the vehicle body 1 to the next detection point, repeating the steps S1-S6 above until all points in the area to be detected are surveyed; after all points are surveyed, the stored raw seismic wave data is exported to an external terminal through the wireless communication module of the control module 5 for subsequent data analysis, such as identifying the seismic wave characteristics corresponding to the cavity through professional software, and finally determining the location, size and depth of the underground cavity.

[0097] Although the specific embodiments of the invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the invention. Based on the technical solutions of the invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the invention.

Claims

1. A device for detecting and exploring underground cavities, characterized in that: The vehicle includes a vehicle body (1), with wheels (11) at the bottom and a vibratory hammer (2) inside the vehicle body (1) capable of vertically impacting the road surface. Two sets of detection components (3) are set on the top of the vehicle body (1), which are arranged horizontally and vertically respectively, to detect whether the vehicle body (1) is in a horizontal state. Several sets of support components (4) are also set around the vehicle body (1), with a detector (416) at the bottom of the support component (4). The probe (417) of the detector (416) can extend out of the support component (4) and couple with the ground to detect the road surface vibration.

2. The underground cavity exploration and detection equipment according to claim 1, characterized in that: The detection component (3) includes two brackets (31), with a stop bar (32) rotatably connected between the two brackets (31). An infrared sensor is provided between the two brackets (31), and the infrared sensor includes a transmitter (33) and a receiver (34). The transmitter (33) is mounted on one bracket (31), and the receiver (34) is mounted on the other bracket (31). The transmitter (33) and the receiver (34) are arranged opposite each other so that the infrared rays emitted by the transmitter (33) can be received by the receiver (34). When the stop bar (32) is rotated to the vertical state, the lower end of the stop bar (32) can block the receiver (34) and the transmitter (33) to block the reception.

3. The underground cavity exploration and detection equipment according to claim 2, characterized in that: Two sets of infrared sensors are provided, and the two sets of infrared sensors are arranged in parallel on both sides of the bracket (31); the middle of the stop bar (32) is hollowed out, so that two vertical plates (35) are formed on both sides of the stop bar (32). The two vertical plates (35) can block the two infrared sensors respectively. When the two vertical plates (35) block the infrared sensors at the same time, the device is in a horizontal state in that direction.

4. The underground cavity exploration and detection equipment according to claim 1, characterized in that: The support assembly (4) includes a boss (41) fixed to the side of the vehicle body (1); a spline shaft (42) is rotatably connected to the bottom of the boss (41), and the spline shaft (42) is driven to rotate by a telescopic motor (43) fixed to the boss (41); a spline sleeve (44) is fitted over the spline shaft (42), and an external thread is opened on the outer side of the spline sleeve (44), and a fixing seat (45) is connected to the corresponding thread on the outer side of the spline sleeve (44), and the fixing seat (45) is fixed to the bottom of the boss (41); The seat (45) is vertically slidably connected to the first sliding sleeve (46), and the bottom of the spline sleeve (44) is rotatably connected to the bottom of the first sliding sleeve (46); the first sliding sleeve (46) is vertically slidably connected to the outside of the second sliding sleeve (47); the spline shaft (42) is also provided with a vertical threaded hole (48), and a threaded rod (49) is threadedly connected in the vertical threaded hole (48). The bottom of the threaded rod (49) passes through the spline sleeve (44) and the first sliding sleeve (46) and is rotatably connected to the bottom of the second sliding sleeve (47).

5. The underground cavity exploration and detection equipment according to claim 4, characterized in that: A first guide block (411) is connected to the outer wall of the fixed base (45), and a first guide groove (410) is opened on the inner wall of the first sliding sleeve (46). The first guide block (411) can slide along the first guide groove (410) to realize the vertical sliding of the first sliding sleeve (46) along the fixed base (45). A second guide block (413) is connected to the outer wall of the first sliding sleeve (46), and a second guide groove (412) is opened on the inner wall of the second sliding sleeve (47). The second guide block (413) can slide along the first groove to realize the vertical movement of the second sliding sleeve (47) along the first sliding sleeve (46).

6. The underground cavity exploration and detection equipment according to claim 4, characterized in that: The bottom of the second sliding sleeve (47) is provided with a vertical sliding groove (414). The detector (416) can move vertically in the vertical sliding groove (414). A spring (415) is connected between the detector (416) and the top of the sliding groove. The spring (415) can press the probe (417) at the bottom of the detector (416) onto the road surface to realize the detection of seismic waves.

7. The underground cavity exploration and detection equipment according to claim 1, characterized in that: The seismic source hammer (2) is driven downward to strike the ground by the drive assembly (6); the drive assembly (6) includes a housing (61), a vertical rod (62) is vertically slidably connected inside the housing (61), the bottom of the vertical rod (62) is connected to the seismic source hammer (2), the vertical rod (62) has a toothed groove (63), and two rotating shafts (64) are provided on the corresponding sides of the vertical rod (62), the rotating shafts (64) are rotatably connected to the side wall of the housing (61); each rotating shaft (64) is connected to an incomplete gear (65), half of the incomplete gear (65) has a tooth. The gears are semi-toothless, with two incomplete gears (65) that can alternately engage with the tooth grooves (63) to push the vertical rod (62) to move vertically. A driven gear (66) is also connected to the rotating shaft (64), and a drive shaft (67) is rotatably connected to the corresponding housing (61). A drive gear (68) is connected to the drive shaft (67). The drive gear (68) is positioned between the two driven gears (66) and works with the driven gears (66) to drive them to rotate. The drive shaft (67) is driven to rotate by a drive motor (69) fixed on the housing (61).

8. The underground cavity exploration and detection equipment according to claim 7, characterized in that: The bottom of the vehicle body (1) is also equipped with a source coupling plate (7). The source coupling plate (7) and the vehicle body (1) are connected by an electromagnet. The electromagnet is fixed on the vehicle body (1). When the electromagnet is de-energized, the source coupling plate (7) falls to the road surface, pushing the vehicle body (1) to move the source hammer (2) to the bottom of the source coupling plate (7) and press down the source coupling plate (7) to increase the seismic wave.

9. A device for detecting and investigating underground cavities according to any one of claims 1-8, characterized in that: The vehicle body (1) is also equipped with a control module (5), which is electrically connected to the detection component (3), the support component (4) and the drive component (6). The control module (5) can receive the electrical signal emitted by the detection component (3) and drive the support component (4) to extend and retract for support. Finally, it drives the drive component (6) to strike the ground to generate seismic waves.

10. A detection method using the underground cavity exploration and detection equipment according to any one of claims 1-9, characterized in that... Includes the following steps: S1. Road surface clearing; determine the survey route and detection points of the road surface to be detected, clear obstacles around the points, and ensure that the vehicle (1) can be parked smoothly and that there are no debris that would affect the transmission of shock waves or the coupling of the detector (416). S2. Vehicle body (1) positioning and leveling; S2.1 Point docking: Move the equipment to the first detection point by using the wheels (11) at the bottom of the vehicle body (1), align the center of the vehicle body (1) with the core area of ​​the point, stop the vehicle and lock the wheels (11); S2.2 Horizontal adjustment; The control module (5) sends a command to the support components (4) around the vehicle body (1) to start the telescopic motor (43) of the support components (4) and drive the spline shaft (42) to rotate; so that the support components (4) are supported on the ground and the probe (417) of the detector (416) touches the ground; S2.3 Horizontal Detection: The control module (5) starts two sets of detection components (3), and the infrared sensors of each set of detection components (3) start working; if the stop bar (32) is not rotated to the vertical position, the infrared light is normally received by the receiver (34), indicating that the equipment is not horizontal; if the stop bar (32) is rotated to the vertical position, the vertical plates (35) on both sides block the two sets of infrared sensors at the same time, the receiver (34) has no signal, and the control module (5) determines that the equipment is horizontal in this direction; if it is not horizontal, the support component (4) on one side is driven to fix according to the tilt condition to realize the adjustment of the vehicle body (1); until the horizontal and vertical detections show that it is horizontal; S3. Seismic waves generated by the source hammer (2): The control module (5) starts the drive motor (69) of the drive assembly (6), the drive motor (69) drives the drive shaft (67) to rotate, and the drive gear (68) on the drive shaft (67) rotates synchronously; the drive gear (68) meshes with the driven gears (66) on both sides, driving the rotating shaft (64) and the incomplete gear (65) on the rotating shaft (64) to rotate; the two incomplete gears (65) alternately engage with the tooth grooves (63) of the vertical rod (62), pushing the vertical rod (62) to move vertically repeatedly, so that the source hammer (2) continuously hammers the ground and generates seismic waves for detection; S4. Signal conversion: When seismic waves from below the ground propagate to different media, they will be reflected and refracted. The detector (416) receives these seismic waves and converts the mechanical seismic wave signal into an electrical signal. S5. Data transmission: The detector (416) transmits the electrical signal to the control module (5) in real time. The control module (5) performs preliminary filtering and amplification on the signal, stores the original seismic wave data, and completes the acquisition of detection data at the current point. S6. Single-point recovery; After the current point data is collected, the control module (5) first stops the drive motor (69) to reset the source hammer (2); then drives the telescopic motor (43) of the support component (4) to reverse, driving the spline shaft (42), spline sleeve (44), and sliding sleeve to rise and retract the detector (416); S7. Repeat at multiple points: Move the vehicle body (1) to the next detection point by using the wheels (11), repeat S1-S6, until all points in the area to be detected are surveyed.

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