Road collapse detection method and device

Abstract

The invention relates to the technical field of road collapse detection, in particular to a road collapse detection method and device. According to the technical scheme, equipment is installed below rearview mirrors on the two sides of a vehicle, and the interior of the equipment comprises four modules including a laser emission module, a laser detection module, a GNSS speed measurement module and a road collapse judgment module. The laser emission module receives a sending instruction sent by the road collapse judgment module and emits laser to the front of a road, the laser falling point may be about 100 m in front of a vehicle, and the value can be adjusted according to different installation inclination angles of the laser emission module; according to the invention, the laser pulse repetition frequency can be set according to the following formula: 0.14 v / delta < = fr < = 0.28 v / delta. The device is installed on the rearview mirrors on the two sides of the vehicle, can continuously detect whether the road ahead collapses or not in the high-speed running process of the vehicle, and can give an early warning to a driver in time if collapse is found, so that the tragedy of vehicle falling is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of road collapse detection, and in particular to a road collapse detection method and a device thereof. Background Art

[0002] Highway collapse accidents caused by natural disasters or quality problems occur from time to time. Each accident will result in the loss of dozens of vehicles and personnel, and cause huge negative social impact. Therefore, those skilled in the art provide a road collapse detection method and device to solve the problems raised in the above background technology. Summary of the invention

[0003] The purpose of the present invention is to provide a road collapse detection method and device thereof in view of the problems existing in the background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: The road collapse detection method comprises the following steps:

[0005] The device is installed under the rearview mirrors on both sides of the vehicle. It includes four modules: laser emission module, laser detection module, GNSS speed measurement module and road collapse judgment module.

[0006] The laser emission module receives the "send" command from the road collapse judgment module and emits laser to the front of the road. The laser landing point may be about 100m in front of the vehicle. This value will be adjusted according to the different installation inclination angles of the laser emission module.

[0007] The present invention suggests that the laser pulse repetition frequency can be set as follows:

[0008] 0.14v / δ≤fr≤0.28v / δ;

[0009] Preferably, the laser detection module receives the "send" command sent by the road collapse judgment module, and after receiving the laser echo pulse reflected from the ground, calculates the distance value according to the delay between the "send" command and the distance value, and sends it to the road collapse judgment module;

[0010] Preferably, the GNSS speed measurement module can obtain the vehicle speed in real time by receiving navigation signals from global satellite navigation systems such as GPS or Beidou, and send it to the road collapse judgment module; at the same time, a map can also be preset to send information such as the angle and slope of the curve of the road ahead to the road collapse judgment module to assist in pattern recognition and improve the accuracy of judgment;

[0011] Preferably, the road collapse judgment module adjusts the laser pulse repetition frequency according to the vehicle speed V obtained from the GNSS speed measurement module, sends a "send" command to the laser emission module and the laser detection module at the same time, and continuously receives the distance value sent by the laser detection module, and then executes the following algorithm to detect whether the road ahead collapses:

[0012] a. Does the accumulated distance points exceed the preset N points? If not, continue to wait for reading the subsequent distance value; if it exceeds, execute the following process;

[0013] b. Take the nearest N point distance value;

[0014] c. Perform pattern matching between the N-point distance value and the road collapse distance value change curve. Does the matching degree (which can be understood as a curve similarity probability) exceed the preset threshold value P? If not, wait for the subsequent distance value to be read and restart the judgment process 1; if it exceeds, execute the following process;

[0015] d. The match count C value is increased by 1. To prevent the false alarm rate (false alarms are considered true alarms) from being too high, it is necessary to match several times before confirming. Therefore, a match count is set to calculate the number of successful matches.

[0016] e. Does the matching count C value exceed the preset threshold value K? If not, wait for the next distance value to be read, perform pattern matching again, and confirm; if exceeded, continue to send an alarm prompt to the driver;

[0017] f. If the driver does not respond to the alarm prompt, the alarm continues; if the driver responds to the alarm, the road collapse detection process ends.

[0018] A road collapse detection device, comprising an installation box, a detection structure, an installation structure and an adjustment structure, wherein the detection structure comprises a closing plate, a grid plate fixedly arranged at the rear end of the closing plate, a laser emission module located above the grid plate and a laser detection module at the upper end of the grid plate, a laser emission head located at the front end of the laser emission module, a GNSS speed measurement module and a road collapse judgment module located at one side of the laser detection module, a guide seat fixedly arranged at the rear end of the installation box and symmetrically distributed, and a guide plate located at the rear end of the closing plate and slidably installed inside the guide seat;

[0019] The adjustment structure includes a base sleeved on the outside of the laser emission module, a second installation shaft fixedly arranged at the lower end of the base and rotatably installed inside the grid plate, a second gear sleeved on the outer wall of the second installation shaft, a rotating shaft located at the front and rear ends of the laser emission module and rotatably installed inside the base, a micro motor fixedly arranged at one end of the base and with the output end connected to the rotating shaft, an electric push rod fixedly arranged on one side of the upper end of the grid plate, and a gear plate fixedly arranged at the telescopic end of the electric push rod and meshing with the second gear.

[0020] Preferably, the front end of the installation box is provided with an installation opening, the closing plate is embedded and installed inside the installation opening, the lower end of the installation box is provided with a ventilation groove, and a filter element and non-woven fabric are embedded and installed inside the ventilation groove. The closing plate is docked with the installation box through the installation opening, and the grid plate is pushed into the installation box for installation of the detection structure. The installation box allows air to circulate inside and outside through the ventilation groove, solid matter in the air is intercepted, and moisture in the air is intercepted by the non-woven fabric to prevent water vapor from entering, and air circulation can carry away the hot gas inside the installation box.

[0021] Preferably, an adjustment port is opened inside the closing plate, the front end of the laser emitting module is located at the rear side of the adjustment port, the laser emitting head is located at the front side of the adjustment port, the outer wall of the laser emitting module is sleeved with a pleated cloth connected to the outer wall of the closing plate, a micro heat pump is arranged at the lower end of the grid plate, an air supply pipe penetrating the closing plate is arranged at the output end of the micro heat pump, and one end of the air supply pipe is connected to a one-way valve nozzle with an air outlet inclined surface facing the laser emitting head.

[0022] Preferably, the upper end of the grid plate is provided with an annular guide rail, the lower end of the base is provided with a pulley symmetrically distributed and slidably mounted inside the guide rail, the upper end of the grid plate is provided with an arched guide rod, one end of the tooth plate is provided with a sliding sleeve slidably sleeved on the outer wall of the guide rod, the mounting structure includes a bearing bracket 1 located at one end of the guide seat, the upper end of the bearing bracket 1 is rotatably mounted with a mounting shaft 1, the opposite end of the guide plate is provided with a tooth groove 1 equidistantly distributed, and the outer wall of the mounting shaft 1 is sleeved with a gear 1 meshing with the tooth groove 1. When the micro heat pump is in operation, the generated hot air flow is transported to the one-way valve nozzle through the air delivery pipe, so that the hot air flow acts on the laser transmitter head, and the laser transmitter head corresponds to the oblique surface of the air outlet of the one-way valve nozzle to avoid shielding the laser transmitter head. The tooth plate rolls inside the guide rail through the pulley to slide and support the lower end of the base, so that the bottom support of the base is stable, and the tooth plate slides on the outer wall of the guide rod through the sliding sleeve to slide and guide the tooth plate during the movement.

[0023] Preferably, the installation box is provided with a support rod suspended below the grid plate, a symmetrically distributed connecting bar is provided at the upper end of the support rod, a card frame located above the gear 1 is provided at one end of the connecting bar, a rotating bar is rotatably installed inside the card frame, a mounting column is provided at the upper end of the mounting shaft 1, the outer wall of the mounting column is provided with two tooth grooves distributed in a ring array, one end of the rotating bar is provided with a card block that is connected to the inside of the tooth groove 2, one end of the card frame is provided with a limit block located at the rear side of the card block, and the outer side of the rotating bar is sleeved with a torsion spring connected to the limit block and the card frame at both ends. When the mounting shaft 1 rotates, the gear 1 and the mounting column are driven to rotate at the same time, and then the tooth groove 2 on the outer wall of the mounting column is driven to push the card block. After the card block is moved, it will automatically reset due to the elasticity of the torsion spring, but when it rotates in the opposite direction, it will be intercepted by the limit block, thereby preventing the mounting column from rotating in the opposite direction and preventing the gear 1 from being pushed and rotated by the guide plate moving toward the mounting port.

[0024] Preferably, a damping bearing is embedded and installed inside one end of the installation box, a screw is rotatably installed inside the damping bearing, a sliding seat suspended below the support rod is provided on the inner wall of the rear end of the installation box, a slider is slidably installed inside the upper end of the sliding seat, a threaded sleeve is provided on the upper end of the sliding seat, the upper end of the sliding seat is threadedly sleeved on the outer wall of the screw and the upper end is connected to the lower end of the support rod, a bearing bracket 2 is provided on one side of the upper end of the sliding seat, one end of the screw is rotatably inserted into the bearing bracket 2, and a torsion ring is provided on one end of the screw. When the screw rotates, damping is applied through the damping bearing to prevent the screw from rotating randomly when not in use, one end of the screw is rotationally supported by the bearing bracket 2, and the stability of the screw is improved when it rotates.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention installs the installation box below the left and right rearview mirrors of the car, the laser emission head of the laser emission module faces the driving direction of the car, the laser emission module is slightly tilted downward to emit laser pulses to the road ahead, the laser detection module detects the echo pulse reflected by the road, and calculates the distance value of the road indicated by the laser according to the delay of the echo pulse relative to the emission pulse. The laser pulses are continuously emitted at periodic intervals, and the number of laser pulses emitted per second is called the pulse repetition frequency, so a series of distance values ​​can be obtained. According to the change law of the distance value, it can be judged whether the road ahead collapses;

[0027] The detection structure is supported by a grid plate, and the laser emission module can be adjusted in longitudinal and lateral positions. The angle of the laser pulse emitted by the laser emission module can be adjusted to adapt to the installation conditions of rearview mirrors of different models, so that the laser emission module can be used effectively and flexibly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a rear cross-sectional three-dimensional structural schematic diagram of the present invention;

[0029] Figure 2 For the present invention Figure 1 Schematic diagram of the three-dimensional structure when viewed from above;

[0030] Figure 3 For the present invention Figure 1 Schematic diagram of the main stereoscopic structure;

[0031] Figure 4 It is a schematic diagram of the three-dimensional structure of the interior of the installation box of the present invention when viewed from above;

[0032] Figure 5 It is a schematic diagram of the side-view stereoscopic structure of the detection structure of the present invention;

[0033] Figure 6 It is a bottom-up stereoscopic structural schematic diagram of the detection structure and the installation structure of the present invention;

[0034] Figure 7 It is a schematic diagram of the three-dimensional structure of the detection structure of the present invention when viewed from above;

[0035] Figure 8 It is a schematic diagram of the three-dimensional structure of the guide seat of the present invention from a side view;

[0036] Fig. 9 It is a schematic diagram of the three-dimensional structure of the laser emission module of the present invention from a side view;

[0037] Fig.10 It is a schematic diagram of the three-dimensional structure of the regulating structure of the present invention from top view;

[0038] Fig.11 It is a schematic diagram of a three-dimensional structure of the installation structure of the present invention from a side view;

[0039] Fig.12 It is a rear perspective structural schematic diagram of the threaded casing of the present invention;

[0040] Fig.13 It is a partial rear-view stereoscopic structural schematic diagram of the screw rod of the present invention;

[0041] Fig.14 It is a rear perspective structural diagram of the gear of the present invention;

[0042] Fig.15 It is a schematic diagram of the three-dimensional structure of the gear of the present invention from top view;

[0043] Fig.16 It is a schematic diagram of the road collapse detection principle of the present invention;

[0044] Fig.17 It is a schematic diagram of a laser distance value variation curve when a road collapses according to the present invention;

[0045] Fig.18This is a schematic diagram of a laser distance value variation curve that needs to be matched when detecting road collapse in the present invention;

[0046] Fig.19 It is a schematic diagram of the structural frame of the road collapse detection structure of the present invention;

[0047] Fig. 20 The figure is a schematic diagram of the road collapse detection algorithm flow of the present invention.

[0048] Reference numerals:

[0049] 100, installation box; 101, ventilation groove; 102, installation port;

[0050] 200, detection structure; 201, closing plate; 202, grid plate; 203, laser detection module; 204, laser emission module; 205, laser emission head; 206, pleated cloth; 207, air supply pipe; 208, one-way valve nozzle; 209, guide plate; 210, guide seat; 211, micro heat pump; 212, adjustment port; 213, GNSS speed measurement module; 214, road collapse judgment module;

[0051] 300, mounting structure; 301, tooth groove 1; 302, clamping frame; 303, connecting strip; 304, bearing bracket 1; 305, supporting rod; 306, threaded sleeve; 307, screw; 308, torsion ring; 309, sliding seat; 310, slider; 311, damping bearing; 312, tooth groove 2; 313, bearing bracket 2; 314, mounting shaft 1; 315, mounting column; 316, limit block; 317, gear 1; 318, torsion spring; 319, clamping block; 320, rotating strip;

[0052] 400, adjustment structure; 401, micro motor; 402, rotating shaft; 403, base; 404, gear 2; 405, pulley; 406, guide rail; 407, electric push rod; 408, tooth plate; 409, sliding sleeve; 410, guide rod; 411, mounting shaft 2. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] See also Figures 1 to 20 , the present invention provides four embodiments:

[0055] Embodiment 1:

[0056] A road collapse detection device, comprising an installation box 100, a detection structure 200, an installation structure 300 and an adjustment structure 400, wherein the detection structure 200 comprises a closing plate 201, a grid plate 202 fixedly disposed at the rear end of the closing plate 201, a laser emitting module 204 located above the grid plate 202 and a laser detection module 203 at the upper end of the grid plate 202, a laser emitting head 205 located at the front end of the laser emitting module 204, a guide seat 210 fixedly disposed at the rear end of the installation box 100 and symmetrically distributed, and a guide plate 209 located at the rear end of the closing plate 201 and slidably mounted inside the guide seat 210;

[0057] The front end of the installation box 100 is provided with an installation opening 102, and the closing plate 201 is fitted and installed inside the installation opening 102;

[0058] A ventilation groove 101 is provided inside the lower end of the installation box 100, and a filter element and non-woven fabric are embedded and installed inside the ventilation groove 101. A micro heat pump 211 is provided at the lower end of the grid plate 202, and an air supply pipe 207 penetrating the closing plate 201 is provided at the output end of the micro heat pump 211. One end of the air supply pipe 207 is connected to a one-way valve nozzle 208 with an air outlet inclined surface facing the laser transmitter head 205;

[0059] The overall structure of the installation box 100 is box-shaped, and the upper end is connected to the lower end of the automobile rearview mirror. The shape of the installation box 100 can be set as needed to adapt to the curvature of the outer wall of the rearview mirror to achieve an aesthetic effect. During the use of the installation box 100, the outside air enters the installation box 100 through the ventilation groove 101. The high-temperature gas generated during the use of the electronic equipment inside the installation box 100 is transported to the outside to avoid the temperature inside the installation box 100 being too high. The electronic equipment is cooled. The closing plate 201 is docked with the installation port 102, and the guide plate 209 is slidably inserted into the guide seat 210. The closing plate 201 is slidably installed in the installation box 100, which is convenient for positioning when the closing plate 201 is fixed.

[0060] Embodiment 2:

[0061] The adjustment structure 400 includes a base 403 sleeved on the outside of the laser emitting module 204, a second mounting shaft 411 fixed at the lower end of the base 403 and rotatably mounted inside the grid plate 202, a second gear 404 sleeved on the outer wall of the second mounting shaft 411, a rotating shaft 402 located at the front and rear ends of the laser emitting module 204 and rotatably mounted inside the base 403, a micro motor 401 fixed at one end of the base 403 and the output end of which is connected to the rotating shaft 402, an electric push rod 407 fixed at one side of the upper end of the grid plate 202, and a toothed plate 408 fixed at the telescopic end of the electric push rod 407 and meshing with the second gear 404;

[0062] An adjustment port 212 is provided inside the closing plate 201, a front end of the laser emitting module 204 is located behind the adjustment port 212, a laser emitting head 205 is located in front of the adjustment port 212, and a pleated cloth 206 connected to the outer wall of the closing plate 201 is sleeved on the outer wall of the laser emitting module 204;

[0063] An annular guide rail 406 is provided at the upper end of the grid plate 202, and pulleys 405 symmetrically distributed and slidably installed inside the guide rail 406 are provided at the lower end of the base 403. An arched guide rod 410 is provided at the upper end of the grid plate 202, and a sliding sleeve 409 slidably sleeved on the outer wall of the guide rod 410 is provided at one end of the tooth plate 408.

[0064] The laser emitting head 205 of the laser emitting module 204 is installed in the adjustment port 212 inside the closing plate 201. During use, the laser emitting module 204 generates pulses, and the laser detection module 203 is used to detect the echo pulse reflected back from the road. It is worth noting that one end of the laser detection module 203 is provided with a laser detection head that penetrates the closing plate 201, and the echo pulse is detected by the laser detection head;

[0065] When the laser emitting module 204 is installed and debugged before use, the electric push rod 407 drives the tooth plate 408 to move, and the tooth plate 408 pushes the gear 1 317. The rotational force of the gear 1 317 acts on the installation shaft 2 411, and then the base 403 rotates, and the base 403 drives the laser emitting head 205 to rotate to adjust the position. When the micro motor 401 is in operation, the laser emitting head 205 is driven by the rotating shaft 402 to adjust the longitudinal angle, and the angle of the laser pulse emitted by the laser emitting module 204 is adjusted. There are differences in the height of the vehicle and the angle of the rearview mirror, thereby realizing the adjustment of different installation conditions of the laser emitting module 204, and the flexibility of the laser emitting module 204 is improved when it is used;

[0066] When the temperature is low, the water vapor adhered to the laser transmitting head 205 and condensed will affect the pulse emission. Therefore, before the vehicle drives, the micro heat pump 211 draws air to heat it and transports it through the air supply pipe 207. The air supply pipe 207 transports the hot air flow into the one-way valve nozzle 208. There are two one-way valve nozzles 208. The hot air flow in the air supply pipe 207 is divided into two one-way valve nozzles 208. One of the one-way valve nozzles 208 corresponds to the laser detection head. The gas flows in one direction, which prevents the outside gas from entering the micro heat pump 211 and the installation box 100 through the air supply pipe 207. The hot air flow melts the frost and ice on the outer wall of the laser transmitting head 205 and the laser detection head, ensuring the stability of the equipment. The end of the one-way valve nozzle 208 is provided with an air nozzle with a narrow internal flow channel. The air nozzle pressurizes the outflowing airflow, and the hot air flow is sprayed to the laser transmitting head 205 and the outer wall of the laser detection head.

[0067] Embodiment three:

[0068] The mounting structure 300 includes a bearing bracket 304 located at one end of the guide seat 210, and a mounting shaft 314 is rotatably mounted on the upper end of the bearing bracket 304. The opposite end of the guide plate 209 is provided with tooth grooves 301 that are equidistantly distributed, and the outer wall of the mounting shaft 314 is sleeved with a gear 317 that meshes with the tooth grooves 301.

[0069] A support rod 305 suspended below the grid plate 202 is arranged inside the installation box 100, and a symmetrically distributed connecting bar 303 is arranged on the upper end of the support rod 305, a clamping frame 302 located above the gear 1 317 is arranged at one end of the connecting bar 303, a rotating bar 320 is rotatably installed inside the clamping frame 302, a mounting column 315 is arranged on the upper end of the mounting shaft 1 314, and the outer wall of the mounting column 315 is provided with tooth grooves 2 312 distributed in a ring array, a clamping block 319 clamped in the inside of the tooth groove 2 312 is arranged at one end of the rotating bar 320, a limiting block 316 located on the rear side of the limiting block 319 is arranged at one end of the clamping frame 302, and a torsion spring 318 is sleeved on the outer side of the rotating bar 320, and the two ends of the torsion spring 318 are respectively connected to the limiting block 316 and the clamping frame 302.

[0070] A damping bearing 311 is embedded and installed inside one end of the installation box 100, and a screw 307 is rotatably installed inside the damping bearing 311. A sliding seat 309 suspended below the support rod 305 is provided on the inner wall of the rear end of the installation box 100, and a slider 310 is slidably installed inside the upper end of the sliding seat 309. A threaded sleeve 306 is provided on the upper end of the slider 310, which is threadedly sleeved on the outer wall of the screw 307 and the upper end is connected to the lower end of the support rod 305. A bearing bracket 2 313 is provided on one side of the upper end of the sliding seat 309, and one end of the screw 307 is rotatably inserted into the bearing bracket 2 313, and a torsion ring 308 is provided at one end of the screw 307.

[0071] When the closing plate 201 is docked and installed with the installation box 100, the closing plate 201 is slidably inserted into the guide seat 210 through the guide plate 209. During this process, the tooth groove 1 301 at one end of the guide plate 209 pushes the gear 1 317, thereby driving the installation shaft 2 411 to rotate. When the installation shaft 2 411 rotates, it drives the installation column 315 to rotate, and the tooth groove 2 312 on the outer wall of the installation column 315 pushes the block 319. Because the block 319 is supported by the rotation bar 320, the torsional force of the torsion spring 318 is applied with a torsional contraction force when the block 319 and the rotation bar 320 rotate. When the block 319 loses the push of the tooth groove 2 312 at the corresponding position, the torsional elasticity of the torsion spring 318 drives the block 319 to reset, and the block 319 enters the next slot 2. When the closing plate 201 is completely fitted with the installation port 102, the installation of the closing plate 201 and the detection structure 200 is completed;

[0072] Because the gear 1 317 is meshed with the tooth groove 1 301, when the closing plate 201 moves toward the outside of the installation box 100, the tooth groove 1 301 will apply a reverse driving force to the gear 1 317. Through the linkage of the installation shaft 1 314 and the installation column 315, the rotational force during installation acts on the block 319 in the reverse direction through the installation column 315. One side of the block 319 is intercepted by the limit block 316, which blocks the rotation of the installation column 315, thereby avoiding the rotation of the gear 1 317, ensuring the stability of the closing plate 201. The closing plate 201 is fixed after being slid and inserted into the specified position, and the installation is convenient.

[0073] When the detection structure 200 needs to be maintained, the torsion ring 308 is grasped to rotate the screw 307, and the screw 307 rotates inside the damping bearing 311. The damping bearing 311 applies resistance to the screw 307 to ensure the stability of the screw 307 when not in use. Because the threaded sleeve 306 is slidably supported inside the slide seat 309 through the slider 310, the threaded sleeve 306 is pushed, thereby driving the support rod 305 to move, and the support rod 305 drives the connecting bar 303 to move, and then drives the clamping frame 302 at one end of the connecting bar 303 to move, and the clamping block 319 moves to one side of the tooth groove 2 312 to end the clamping of the tooth groove 2 312. When the mounting shaft 1 314 rotates in the opposite direction, the interception of the tooth groove 2 312 by the clamping block 319 is released, thereby ensuring the effective pulling and pulling of the guide plate 209, and the disassembly and assembly of the closing plate 201 is convenient, which facilitates the maintenance of the detection structure 200.

[0074] Embodiment 4:

[0075] A road collapse detection method, the road collapse detection method steps are as follows:

[0076] The method of the present invention is to install a laser emission detection structure 200 on each of the left and right rearview mirrors of the vehicle. Each laser emission detection structure 200 contains a laser emission module 204 and a laser detection module 203. The laser emission module 204 is slightly tilted downward to emit laser pulses at L0m on the road ahead. The laser detection module 203 is used to detect the echo pulse reflected back from the road. According to the delay of the echo pulse relative to the emission pulse, the distance value of the road indicated by the laser can be calculated. By continuously emitting laser pulses at periodic intervals (the number of laser pulses emitted per second is called the pulse repetition frequency), a series of distance values ​​can be obtained. According to the change law of the distance value, it can be judged whether the road ahead has collapsed;

[0077] Assume that the vehicle speed is Vkm / h and the pulse repetition frequency of the laser detection emission is fr.

[0078] In an ideal situation where the road is straight and there is no collapse, the vehicle travels at a constant speed, and the distance value R detected by adjacent laser pulses will not change much (assuming that the laser point detects 100m ahead and the round trip is 200m, the delay between the echo pulse and the transmitting pulse is about 660ns, and the vehicle traveling at a speed of 100km / h only travels 18.3um during this delay time, which can be completely ignored). At this time, the situation is as follows Fig.16 As shown in (1).

[0079] As the vehicle moves forward, the laser will land on the collapsed area. Assuming that the road ahead collapses by Lm, the laser reflection will fall on the front wall of the collapsed pit instead of the road surface before the collapse. The detected distance value R will suddenly increase by Lm. Fig.16 As shown in (2).

[0080] The vehicle continues to move forward, and the laser landing point is still on the front wall of the collapse pit. The landing point gradually moves upward, and the detected distance value R will gradually decrease. The rate of change of the distance decrease is approximately equal to the vehicle speed. Assuming that the vehicle speed is 100km / h, the distance value detected by the laser decreases by about 27.8m per second. Fig.16 As shown in (3).

[0081] As the vehicle continues to move forward, the laser landing point will jump out of the edge of the collapse and fall on the road surface in front of the collapse pit. The laser distance value R will remain basically stable thereafter.

[0082] According to the above principle, if the detected laser distance value changes as follows Fig.17 As shown, it can be determined that the road ahead has collapsed and a danger warning can be given. When the road collapse is very wide, it will take a long time for the waiting distance value to change from (3) to (4), and the vehicle will have traveled a considerable distance, so the alarm will be greatly delayed. Therefore, in actual detection, it is only necessary to detect changes from (1) to (2) to (3) to give a danger warning, that is, to detect changes in the distance value similar to Fig.18 Such a curve and such a change in distance value (the detection algorithm is actually a simple pattern matching algorithm) can give a dangerous warning of road collapse ahead;

[0083] In order to detect Fig.16 In scenario (3), the slope of the distance value R requires a range of laser pulse repetition frequency, that is, the interval between two laser pulses cannot be too large or too small. If the pulse interval is too small, the distance values ​​detected by the two laser pulses may be equal due to the limited laser distance detection accuracy, which increases the complexity of the algorithm; if the pulse interval is too large, the detection time will increase, affecting the safety of vehicles and personnel;

[0084] The present invention suggests that the laser pulse repetition frequency can be set as follows: 0.14v / δ≤fr≤0.28v / δ

[0085] In the above formula, δ is the laser distance detection accuracy, unit is m; V is the vehicle speed, unit is km / h.

[0086] Assuming the vehicle speed is 100 km / h and the distance detection accuracy is about 1m, the laser pulse repetition frequency can be controlled at 14-28 Hz. Of course, in actual applications, the pulse repetition frequency does not necessarily change in real time with the vehicle speed, but can be set to a series of step values. When the vehicle speed changes beyond a certain range, the pulse repetition frequency will change once.

[0087] Notice Fig.17 The slope of the middle line segment (3) is approximately equal to the vehicle speed, and the laser pulse repetition frequency is also related to the vehicle speed. Therefore, the detection structure 200 of the present invention needs to obtain the current vehicle speed value by some means. In the present invention, the GNSS satellite positioning speed measurement technology is used to obtain the vehicle speed in real time.

[0088] In order to more clearly understand the above-mentioned purpose, features and algorithms of the present invention, the present invention is further described below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention:

[0089] The installation box 100 is installed under the rearview mirrors on both sides of the vehicle, and includes four modules: a laser emission module 204, a laser detection module 203, a GNSS speed measurement module 213 and a road collapse judgment module 214;

[0090] The laser emitting module 204 receives the "send" command sent by the road collapse judgment module 214, and emits a laser to the front of the road. The laser landing point may be about 100m in front of the vehicle. This value will be adjusted according to the different installation inclination angles of the laser emitting module 204;

[0091] The laser detection module 203 receives the "send" command sent by the road collapse judgment module 214, and after receiving the laser echo pulse reflected from the ground, calculates the distance value according to the delay between the "send" command and the distance value, and sends it to the road collapse judgment module 214;

[0092] The GNSS speed measurement module 213 can obtain the vehicle speed in real time by receiving navigation signals from global satellite navigation systems such as GPS or Beidou, and send it to the road collapse judgment module 214; at the same time, a map can also be preset to send information such as the curve angle and slope of the road ahead to the road collapse judgment module 214 to assist pattern recognition and improve the accuracy of judgment.

[0093] The road collapse judgment module 214 adjusts the laser pulse repetition frequency according to the vehicle speed V obtained from the GNSS speed measurement module 213, sends a "send" command to the laser emission module 204 and the laser detection module 203 at the same time, and continuously receives the distance value sent by the laser detection module 203, and then executes the following algorithm to detect whether the road ahead collapses:

[0094] a. Does the accumulated distance points exceed the preset N points? If not, continue to wait for reading the subsequent distance value; if it exceeds, execute the following process;

[0095] b. Take the nearest N point distance value;

[0096] c. Perform pattern matching between the N-point distance value and the road collapse distance value change curve. Does the matching degree (which can be understood as a curve similarity probability) exceed the preset threshold value P? If not, wait for the subsequent distance value to be read and restart the judgment process 1; if it exceeds, execute the following process;

[0097] d. The match count C value is increased by 1. To prevent the false alarm rate (false alarms are considered true alarms) from being too high, it is necessary to match several times before confirming. Therefore, a match count is set to calculate the number of successful matches.

[0098] e. Does the matching count C value exceed the preset threshold value K? If not, wait for the next distance value to be read, perform pattern matching again, and confirm; if exceeded, continue to send an alarm prompt to the driver;

[0099] f. If the driver does not respond to the alarm prompt, the alarm continues; if the driver responds to the alarm, the road collapse detection process ends.

[0100] The above-mentioned specific embodiments are only several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above-mentioned embodiments, those skilled in the art can make various alternative improvements and combinations to the above-mentioned specific embodiments.

[0101] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A road collapse detection method, characterized in that: The steps of the road collapse detection method are as follows: The device is installed below the rearview mirrors on both sides of the vehicle, and includes four modules inside: a laser emission module (204), a laser detection module (203), a GNSS speed measurement module (213) and a road collapse judgment module (214); The laser emitting module (204) receives the "send" instruction sent by the road collapse judgment module (214) and emits a laser toward the front of the road. The laser landing point may be about 100 meters in front of the vehicle. This value may be adjusted according to the different installation inclination angles of the laser emitting module (204); The present invention suggests that the laser pulse repetition frequency can be set as follows: 0.14v / δ≤fr≤0.28v / δ.

2. A road collapse detection method according to claim 1, characterized in that: The laser detection module (203) receives the "send" command sent by the road collapse judgment module (214), and after receiving the laser echo pulse reflected from the ground, calculates the distance value according to the delay between the "send" command and sends it to the road collapse judgment module (214).

3. A road collapse detection method according to claim 1, characterized in that: The GNSS speed measurement module (213) can obtain the vehicle speed by receiving navigation signals from global satellite navigation systems such as GPS or Beidou, and send the speed to the road collapse judgment module (214); at the same time, a map can be preset to send information such as the angle and slope of the curve of the road ahead to the road collapse judgment module (214) to assist in pattern recognition and improve the accuracy of judgment.

4. A road collapse detection method according to claim 1, characterized in that: The road collapse judgment module (214) adjusts the laser pulse repetition frequency according to the vehicle speed V obtained from the GNSS speed measurement module (213), sends a "send" instruction to the laser emission module (204) and the laser detection module (203) at the same time, and continuously receives the distance value sent by the laser detection module (203), and then executes the following algorithm to detect whether the road ahead collapses: a. Does the accumulated distance points exceed the preset N points? If not, continue to wait for reading the subsequent distance value; if it exceeds, execute the following process; b. Take the nearest N point distance value; c. Perform pattern matching between the N-point distance value and the road collapse distance value change curve. Does the matching degree (which can be understood as a curve similarity probability) exceed the preset threshold value P? If not, wait for the subsequent distance value to be read and restart the judgment process 1; if it exceeds, execute the following process; d. The match count C value is increased by 1. To prevent the false alarm rate (false alarms are considered true alarms) from being too high, it is necessary to match several times before confirming. Therefore, a match count is set to calculate the number of successful matches. e. Does the matching count C value exceed the preset threshold value K? If not, wait for the next distance value to be read, perform pattern matching again, and confirm; if exceeded, continue to send an alarm prompt to the driver; f. If the driver does not respond to the alarm prompt, the alarm continues; if the driver responds to the alarm, the road collapse detection process ends.

5. A road collapse detection device, comprising a mounting box (100), a detection structure (200), a mounting structure (300) and an adjustment structure (400), characterized in that: The detection structure (200) comprises a closing plate (201), a grid plate (202) fixedly disposed at the rear end of the closing plate (201), a laser emitting module (204) located above the grid plate (202) and a laser detection module (203) at the upper end of the grid plate (202), a laser emitting head (205) located at the front end of the laser emitting module (204), a GNSS speed measurement module (213) and a road collapse judgment module (214) located at one side of the laser detection module (203), a guide seat (210) fixedly disposed at the rear end of the installation box (100) and symmetrically distributed, and a guide plate (209) located at the rear end of the closing plate (201) and slidably mounted inside the guide seat (210); The regulating structure (400) comprises a base (403) sleeved on the outside of the laser emitting module (204), a second mounting shaft (411) fixedly disposed at the lower end of the base (403) and rotatably mounted inside the grid plate (202), a second gear (404) sleeved on the outer wall of the second mounting shaft (411), a rotating shaft (402) located at the front and rear ends of the laser emitting module (204) and rotatably mounted inside the base (403), a micro motor (401) fixedly disposed at one end of the base (403) and having an output end connected to the rotating shaft (402), an electric push rod (407) fixedly disposed on one side of the upper end of the grid plate (202), and a toothed plate (408) fixedly disposed at the telescopic end of the electric push rod (407) and meshing with the second gear (404).

6. A road collapse detection device according to claim 5, characterized in that: The front end of the installation box (100) is provided with an installation opening (102), the closing plate (201) is embedded and installed inside the installation opening (102), the lower end of the installation box (100) is provided with a ventilation groove (101), and a filter element and non-woven fabric are embedded and installed inside the ventilation groove (101).

7. A road collapse detection device according to claim 5, characterized in that: The closed plate (201) is provided with an adjustment port (212) inside, the front end of the laser emitting module (204) is located at the rear side of the adjustment port (212), the laser emitting head (205) is located at the front side of the adjustment port (212), the outer wall of the laser emitting module (204) is sleeved with a pleated cloth (206) connected to the outer wall of the closed plate (201), the lower end of the grid plate (202) is provided with a micro heat pump (211), the output end of the micro heat pump (211) is provided with an air supply pipe (207) penetrating the closed plate (201), and one end of the air supply pipe (207) is connected to a one-way valve nozzle (208) with an air outlet inclined surface facing the laser emitting head (205).

8. A road collapse detection device according to claim 5, characterized in that: The upper end of the grid plate (202) is provided with an annular guide rail (406), the lower end of the base (403) is provided with a pulley (405) symmetrically distributed and slidably mounted inside the guide rail (406), the upper end of the grid plate (202) is provided with an arched guide rod (410), one end of the tooth plate (408) is provided with a sliding sleeve (409) slidably sleeved on the outer wall of the guide rod (410), the mounting structure (300) comprises a bearing bracket (304) located at one end of the guide seat (210), the upper end of the bearing bracket (304) is rotatably mounted with a mounting shaft (314), the opposite end of the guide plate (209) is provided with tooth grooves (301) distributed at equal intervals, and the outer wall of the mounting shaft (314) is sleeved with a gear (317) meshing with the tooth grooves (301).

9. A road collapse detection device according to claim 8, characterized in that: The installation box (100) is provided with a support rod (305) suspended below the grid plate (202), and a symmetrically distributed connecting bar (303) is provided at the upper end of the support rod (305); a clamping frame (302) located above the gear one (317) is provided at one end of the connecting bar (303); a rotating bar (320) is rotatably installed inside the clamping frame (302); and a mounting column (315) is provided at the upper end of the mounting shaft one (314). The outer wall of the mounting column (315) is provided with tooth grooves (312) distributed in a ring array, one end of the rotating bar (320) is provided with a clamping block (319) clamped in the inside of the tooth groove (312), one end of the clamping frame (302) is provided with a limit block (316) located at the rear side of the clamping block (319), and the outer side of the rotating bar (320) is sleeved with a torsion spring (318) with two ends respectively connected to the limit block (316) and the clamping frame (302).

10. A road collapse detection device according to claim 9, characterized in that: A damping bearing (311) is embedded and installed inside one end of the installation box (100), and a screw rod (307) is rotatably installed inside the damping bearing (311). A sliding seat (309) suspended below the support rod (305) is provided on the inner wall of the rear end of the installation box (100), and a slider (310) is slidably installed inside the upper end of the sliding seat (309). The upper end of the slider (310) is provided with a threaded sleeve (306) which is threadedly sleeved on the outer wall of the screw rod (307) and the upper end is connected to the lower end of the support rod (305). A bearing bracket 2 (313) is provided on one side of the upper end of the sliding seat (309), and one end of the screw rod (307) is rotatably inserted into the inside of the bearing bracket 2 (313). A torsion ring (308) is provided at one end of the screw rod (307).

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