Airport runway health state monitoring method based on millimeter wave radar

Abstract

The invention discloses an airport runway health state monitoring method based on millimeter-wave radars. A monitoring platform installed on a carrier, a plurality of millimeter-wave radars installed on the monitoring platform and a large-broadband snow detection radar ponding depth detection device are included. An airport runway is monitored in real time through a plurality of millimeter wave radars, an industrial camera is adopted to collect image data, whether damage or foreign matter exists on the pavement is judged, and the specific position of the damage or foreign matter is determined; respectively measuring the thickness of ice and snow covered on the airport runway and the depth of accumulated water by adopting a large-broadband snow detection radar and an accumulated water depth detection device; and storing the collected original data and the analysis result, and performing early warning based on the analysis result. Intelligent monitoring is carried out on the health state of the airport runway based on the millimeter wave radar, runway data are collected and analyzed in real time, and the pavement information of the airport runway to be monitored can be timely and accurately found in combination with a signal processing and recognition technology, so that the accident risk caused by the problem of the airport runway is reduced, and a large amount of manpower and material resources are saved.

Description

Technical Field

[0001] The present invention relates to the field of airport runway monitoring, and in particular to a method for monitoring the health status of an airport runway based on millimeter wave radar. Background Art

[0002] Airport runway damage Due to the impact and heavy load during aircraft takeoff and landing, the grounded part of the runway is easily damaged by the impact of the aircraft landing, resulting in unevenness or cracks on the runway. In order to ensure the flatness of the airport runway surface, maintenance personnel need to regularly inspect the surface wear of the runway. However, due to the long runway, manual inspection is a large workload. Airport runway foreign matter refers to foreign objects in the flight area that may cause harm to aircraft or airport staff, mainly including gravel, tools, bolts, fallen aircraft parts, etc. It will bring serious safety hazards and property loss risks to aircraft takeoff and landing. Manual inspection and cleaning of airport runways reduces the capacity of the airport. At the same time, limited by the quality of inspection personnel and weather conditions, the reliability of monitoring is not high.

[0003] In addition, depending on the season, airport runways may be affected by natural environments such as rain, snow, and ice. When the thickness of rain, snow, and ice exceeds a certain level, the aircraft will slip during takeoff and landing, causing serious safety accidents. Currently, airport runways lack an effective method for identifying the thickness of runway covers. Among them, the existing monitoring devices for water film thickness are mostly pre-buried and cannot actively monitor the entire runway. The means of detecting snow and ice thickness are still limited to manual inspections. Summary of the invention

[0004] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a method for monitoring the health status of an airport runway based on millimeter-wave radar. The method monitors damage to the airport runway, foreign objects, and the thickness of ice and snow covering the airport runway through a monitoring platform installed on a vehicle and a number of millimeter-wave radars and various sensors on the monitoring platform, and issues early warnings, thereby improving inspection efficiency, having a high level of automation, and reducing the safety risks of aircraft takeoff and landing.

[0005] Technical solution: To achieve the above-mentioned purpose, a method for monitoring the health status of an airport runway based on millimeter-wave radar of the present invention comprises a monitoring platform installed on a vehicle, a plurality of millimeter-wave radars and a wide-bandwidth snow-penetrating radar installed on the monitoring platform; the airport runway is monitored in real time by a plurality of millimeter-wave radars to obtain radar data of the airport runway; the collected radar data is filtered and pre-processed for denoising by using a fractional-order monostable system variable-scale system resonance method to obtain pre-processed radar data; based on the extraction of echo energy intensity signals from the pre-processed radar data, the peak-to-peak value change in the energy intensity signal is calculated to determine whether there is damage or foreign matter on the road surface, and an industrial camera is used to collect image data to determine the specific location of the damage or foreign matter; a wide-bandwidth snow-penetrating radar is used to monitor the thickness of ice and snow covering the airport runway, and the thickness of ice and snow is measured by a radar signal energy attenuation method and a radar relative ranging method; the collected raw data and analysis results are stored, and an early warning is issued based on the analysis results.

[0006] Furthermore, the fractional-order monostable system variable-scale system resonance method includes a monostable model and a fractional-order system resonance model; the monostable model is:

[0007]

[0008] The fractional-order system resonance model is:

[0009]

[0010] Substituting the monostable model into the fractional-order system resonance model, the nonlinear system equation of the fractional-order monostable system is obtained:

[0011]

[0012] In the formula, α is the derivative order.

[0013] Furthermore, the time scale and coordinate transformation are introduced and substituted into the nonlinear system equation of the fractional-order monostable system to obtain:

[0014] τ=βt,x(t)=z(τ)

[0015]

[0016] Where β is the scale factor and τ is the time constant;

[0017] make,

[0018]

[0019] The nonlinear system equation of the fractional-order monostable system becomes:

[0020]

[0021] After the scale transformation, the period of the input signal increases from the original T to βT, and its amplitude returns to the original 1 / β; the amplitude of the radar echo signal is amplified back to the initial scale so that the echo signal achieves system resonance:

[0022]

[0023] The scale transformation of the above equation is used to obtain the variable scale fractional order system resonance equation under the excitation of the millimeter wave radar echo signal;

[0024]

[0025] In the formula, α is the derivative order, a1 is the constant term, and b1 is the nonlinear term coefficient;

[0026] By adjusting the system's derivative order α, constant term a1, and nonlinear term coefficient b1, the fractional-order system can achieve the optimal output state for the millimeter-wave radar signal and realize the noise reduction processing of the millimeter-wave radar signal.

[0027] Furthermore, based on the extraction of the echo energy intensity signal in the preprocessed radar data, the peak-to-peak value change in the energy intensity signal is calculated. When the millimeter-wave radar echo is significantly weakened, the airport runway pavement is dented or cracked, and the degree of damage to the airport runway is judged by the size of the peak-to-peak value change of the echo signal; at this time, an industrial camera is used to capture image data of the airport runway, and the shape and location of the pavement damage are determined by analysis, and an early warning is issued. Notification; when the millimeter-wave radar echo is significantly enhanced, there are foreign objects or pavement protrusions on the airport runway pavement, and the size of the foreign objects or protrusions is determined by the peak-to-peak value change of the echo signal; at this time, an industrial camera is used to capture image data of the airport runway, and the type, volume and location of the foreign objects are determined by analysis, and an early warning is issued. Notification.

[0028] Furthermore, an airport runway pavement cleaning device and a water depth detection device are installed on the lower surface of the monitoring platform, and a temperature sensor is installed on the monitoring platform; when the wide-band snow detection radar detects that the thickness of ice and snow does not exceed a threshold value H, the snow shovel in the airport runway pavement cleaning device is in a retracted state and does not shovel snow; at this time, the temperature sensor monitors the temperature of the airport runway pavement, and when the temperature is higher than 0 degrees Celsius, the water depth detection device lowers a resistive liquid level sensor to detect the depth of accumulated water caused by melted ice and snow; when the ambient temperature is not higher than 0 degrees Celsius, the water depth detection device retracts the resistive liquid level sensor.

[0029] Furthermore, when the wide-band snow-detecting radar detects that the thickness of ice and snow exceeds a threshold value H, the snow shovel in the airport runway pavement cleaning device is in an extended state to shovel snow; at this time, the temperature sensor monitors the temperature of the airport runway pavement. When the temperature is higher than 0 degrees Celsius, the water depth detection device lowers the resistive liquid level sensor to detect the depth of the accumulated water melted by ice and snow, and switches the snow shovel in the airport runway pavement cleaning device to a retracted state; when the ambient temperature is higher than 0 degrees Celsius, the water depth detection device retracts the resistive liquid level sensor.

[0030] Furthermore, the radar signal propagation direction of the wide-bandwidth snow-penetrating radar is perpendicular to the airport runway surface.

[0031] Furthermore, in the radar relative ranging method, the propagation time t of the microwave signal measured by the millimeter wave radar in the FMCW mode in the medium is proportional to the thickness h of the medium multiplied by the speed v of the electromagnetic wave in the medium, that is, the time from transmission to reception:

[0032]

[0033] In the formula, v x =c / n x ′c is the speed of light; n x ' is the effective actual refractive index; ε x The dielectric constant of ice or snow;

[0034]

[0035] In the formula, h a and h i are the distances of the radar in the air and in the ice and snow, and are the effective dielectric constants of air and ice and snow, respectively.

[0036] Beneficial effects: The present invention provides a method for monitoring the health status of airport runways based on millimeter-wave radar, which captures runway pavement information through millimeter waves, realizes the identification of airport runway pavement damage, detects pavement cracks and depressions caused by aircraft takeoff and landing, etc., expands the detection means in the aviation field, and improves the inspection efficiency; the monitoring of foreign objects on the airport runway can be carried out by means of a vehicle to quickly inspect the entire runway before the aircraft takes off and lands, and multiple radars scan together to improve the recognition accuracy of smaller foreign objects; the fractional-order monostable system can better adapt to the change in echo intensity, and the impact characteristic component of the signal can be better enhanced by this method; two millimeter-wave radar ice and snow thickness measurement methods are proposed, which can meet the measurement needs of ice and snow of different thicknesses, and solve the problem that the thickness of the airport runway cover cannot be automatically inspected; the working mode is switched autonomously according to environmental information, which has a high level of automation, saves a lot of manpower, and reduces the safety risk of aircraft takeoff and landing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The flowchart of the airport runway health status monitoring method based on millimeter wave radar is shown in FIG.

[0038] Figure 2 This is the principle diagram of measuring ice and snow thickness using millimeter wave radar echo energy;

[0039] Figure 3 This is a top view of the monitoring platform;

[0040] Figure 4 This is the left view of the monitoring platform;

[0041] Figure 5 This is a schematic diagram of the structure of the runway pavement cleaning device;

[0042] Figure 6 This is a schematic diagram of the structure of a water depth detection device. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings.

[0044] like Figure 1 As shown, a method for monitoring the health status of an airport runway based on millimeter-wave radar includes a monitoring platform 10 installed on a vehicle, a plurality of millimeter-wave radars 20 installed on the monitoring platform 10, and a wide-bandwidth snow-penetrating radar 40; an industrial camera 30 is installed on the monitoring platform 10, and the monitoring platform 10 used can be installed on different types of vehicles according to the actual conditions of the airport, and the vehicle carries the monitoring platform to circulate on the airport runway surface for monitoring; through various sensors installed on the monitoring platform 10, the required millimeter-wave radar data and image data, etc. are obtained; the airport runway is monitored in real time by a plurality of millimeter-wave radars, and the radar data of the airport runway is obtained; millimeter waves have the advantages of small propagation attenuation and strong environmental anti-interference ability, and can work normally in rain, snow, fog and other weather conditions.

[0045] The collected radar data is filtered and pre-processed by using the fractional-order monostable system variable-scale system resonance method to obtain the pre-processed radar data. In the denoising process of the radar signal, the fractional-order monostable system variable-scale system resonance method is used to adjust the derivative order of the system and the parameters of the linear and nonlinear terms so that the fractional-order system can achieve the optimal output state for the radar signal, thereby realizing the noise reduction of the radar signal. The fractional-order monostable system can better adapt to the change of echo intensity. This method can better enhance the impact characteristic component of the signal. Based on the extraction of the echo energy intensity signal in the pre-processed radar data, the peak-to-peak value change in the energy intensity signal is calculated, the appearance point of the characteristic target is located, and it is judged whether there is damage or foreign matter on the road surface. The industrial camera 30 is used to collect image data to determine the specific location of the damage or foreign matter. The industrial camera 30 is used to sample and mark the abnormal values ​​observed by the millimeter-wave radar in real time. At the same time, the combination of the industrial camera and the millimeter-wave radar strengthens the identification of the type and volume of foreign matter. Specifically, the image of the radar echo signal can be analyzed by observing it, and the change of the peak-to-peak value is calculated based on the waveform diagram of the echo signal.

[0046] A wideband snow-penetrating radar 40 is used to monitor the thickness of the ice and snow covering the airport runway, and the thickness of the ice and snow is measured by the radar signal energy attenuation method and the radar relative ranging method; whether the thickness of the covering exceeds 15 cm, there are two ice and snow thickness identification modes: radar energy attenuation method and radar relative ranging method; radar energy attenuation method is mainly used to identify ice and snow with a thickness exceeding 15 cm, and radar relative ranging method is used to identify ice and snow with a thickness not exceeding 15 cm; if it does not exceed 15 cm, the radar echo energy attenuation method can no longer meet the demand due to the wavelength and transmission power of the millimeter-wave radar, and it is impossible to accurately detect the thickness of ice and snow, so the radar relative ranging method is used. The radar relative ranging method realizes the measurement of ice and snow thickness, and the wideband snow-penetrating radar 40 carried on the monitoring platform 10 simultaneously measures the distance of the runway surface from the radar and the distance of the ice and snow covering surface from the radar in a straight line, and the relative difference between the two is the thickness of the ice and snow. Radar energy attenuation method: For semi-transparent media such as ice or snow, radar waves are partially transmitted, attenuated and reflected. The received power is related to the dielectric contrast in the medium and the loss caused by volume scattering, attenuation and diffusion effects. The thickness of ice and snow is measured based on this.

[0047] The collected raw data and analysis results are stored, and early warnings are issued based on the analysis results; reports are generated based on the identification of road damage and foreign objects and road coverings under special weather conditions. When foreign objects or damage are detected on the airport runway, an early warning is issued to notify monitoring personnel to carry out maintenance; when the thickness of ice and snow is detected, monitoring personnel are notified to clean the airport runway to ensure its normal operation.

[0048] like Figure 2 As shown, the fractional-order monostable system variable-scale system resonance method includes a monostable model and a fractional-order system resonance model; the monostable model is:

[0049]

[0050] In the formula, a and b are system parameters;

[0051] The fractional-order system resonance model is:

[0052]

[0053] Substituting the monostable model into the fractional-order system resonance model, the nonlinear system equation of the fractional-order monostable system is obtained:

[0054]

[0055] Where α is the derivative order, x(t) is the output enhanced signal, s(t) is the characteristic signal to be enhanced, and a and b are system parameters.

[0056] However, the characteristic frequency value in the millimeter-wave radar echo signal is usually much greater than 1. In this case, if the system parameters at the original scale are continued to be used, it is difficult to make the system produce the best resonance. Therefore, the variable scale method needs to be introduced to help find matching parameters; the time scale and coordinate transformation are introduced and substituted into the nonlinear system equation of the fractional-order monostable system to obtain:

[0057] τ=βt,x(t)=z(τ)

[0058]

[0059] Where β is the scale factor and τ is the time constant;

[0060] make,

[0061]

[0062] The nonlinear system equation of the fractional-order monostable system becomes:

[0063]

[0064] After the scale transformation, the period of the input signal increases from the original T pulse width to βT pulse width, and its amplitude returns to 1 / β of the original; the amplitude of the radar echo signal is amplified back to the initial scale so that the echo signal achieves system resonance:

[0065]

[0066] The scale transformation of the above equation is used to obtain the variable scale fractional order system resonance equation under the excitation of the millimeter wave radar echo signal;

[0067]

[0068] In the formula, α is the derivative order, a1 is the constant term, and b1 is the nonlinear term coefficient;

[0069] By adjusting the system's derivative order α, constant term a1, and nonlinear term coefficient b1, the fractional-order system can achieve the optimal output state for the millimeter-wave radar signal and realize the noise reduction processing of the millimeter-wave radar signal.

[0070] like Figure 3 As shown, several millimeter-wave radars are single-handed single-shot modulated millimeter-wave radars with the same starting frequency of 60 GHz, and the millimeter-wave radars include at least five, which collect the pavement health status of the airport runway in real time and improve the recognition accuracy of smaller foreign objects. The invention also includes an industrial computer 50, a wireless communicator 60, a data processing module, a terminal computer 90 and a power module 100; the data processing module is used to perform denoising and filtering on the collected millimeter wave radar data to obtain a signal with enhanced effective characteristic components, and the data processing module is located in the industrial computer 50 or the terminal computer 90; the power module 100 is used to supply power to the millimeter wave radar 20, the industrial camera 30, the wide-bandwidth snow detection radar 40, the industrial computer 50, the runway pavement cleaning device 70, the water depth detection device 80 and the wireless communicator 60; the industrial computer 50 is used to determine the recognition mode of the method, and to change the radar recognition mode and adjust the corresponding sensors and functional structures according to the ambient temperature, rainfall and ice and snow conditions; the wireless communicator 60 is used to transmit the millimeter wave radar data stored in the industrial computer to the terminal computer, and implement the operation instructions of the terminal computer to the millimeter wave radar; the terminal computer 90 is used to obtain the millimeter wave radar signal processing result of the industrial computer received by the wireless communicator, obtain the airport runway status information, control the millimeter wave radar working mode, store data and generate a detection report.

[0071] Based on the extraction of the echo energy intensity signal in the pre-processed radar data, the peak-to-peak value change in the energy intensity signal is calculated. When the millimeter-wave radar echo is significantly weakened, the airport runway pavement will be dented or cracked, including pavement dents and cracks, and the damage degree of the airport runway will be judged by the size of the peak-to-peak value change of the echo signal; at this time, an industrial camera is used to shoot image data of the airport runway, and the shape and location of the pavement damage are determined by analysis, and an early warning is issued to notify the staff to process the damaged location and stop moving forward; when the millimeter-wave radar echo is significantly enhanced, there are foreign objects or pavement protrusions on the airport runway pavement, including gravel, tools and metal parts, and the size of the foreign objects or protrusions is determined by the peak-to-peak value change of the echo signal; at this time, an industrial camera is used to shoot image data of the airport runway, and the type, volume and location of the foreign objects are determined by analysis, and an early warning is issued to notify the staff to remove the foreign objects from the location of the foreign objects and stop moving forward.

[0072] like Figure 5 As shown, the lower surface of the monitoring platform 10 is installed with an airport runway pavement cleaning device 70 and a water depth detection device 80, and a temperature sensor is installed on the monitoring platform 10; the airport runway pavement cleaning device 70 includes an electric push rod 71, a snow shovel 72, a front rotating shaft base 73, a first rotating shaft base 74 and a connecting bolt 75; the bottom of the electric push rod 71 is rotatably connected to the lower surface of the monitoring platform 10 through the front rotating shaft base 73, the bottom of the snow shovel 72 is rotatably connected to the lower surface of the monitoring platform 10 through the first rotating shaft base 74, and the head of the electric push rod 71 is rotatably connected to the snow shovel 72 through the connecting bolt 75. The electric push rod 71 is retracted and extended by the industrial computer 50 to achieve the snow shovel being retracted to a retracted state and extended to an extended state. Figure 5 As shown, the moving direction of the vehicle is the direction in which the airport runway pavement cleaning device 70 follows the vehicle.

[0073] like Figure 4As shown, a vehicle fixing ring 11 is fixedly installed on the side of the monitoring platform 10 opposite to the moving direction, and the vehicle fixing ring 11 is used to fix the monitoring platform 10 to the front end of the vehicle, such as a shuttle bus or other airport vehicles such as maintenance vehicles; one end of the platform support frame 12 is fixedly installed on the side of the monitoring platform 10 opposite to the moving direction, and the platform support frame 12 is perpendicular to the lower surface of the monitoring platform 10, and the other end of the platform support frame 12 is fixedly connected to the lower surface of the monitoring platform 10 through a support rod, and the support rod is tilted to enhance the stability of the monitoring platform 10; the upper surface of the monitoring platform 10 is fixedly connected to one end of the support seat 13, and the other end of the support seat 13 is fixedly installed with a wide-bandwidth snow detection radar 40, and the support seat 13 is tilted upward; a number of millimeter wave radars 20 are installed on the upper surface of the monitoring platform 10, and an industrial computer 50, a wireless communicator 60 and other sensors are installed on the upper surface of the monitoring platform 10; a runway pavement cleaning device 70, a water depth detection device 80, and a power module 100 are installed on the lower surface of the monitoring platform.

[0074] like Figure 6 As shown, the water depth detection device 80 includes a second rotating shaft base 81, an auxiliary support rod 82, an anti-collision protection rod 83, a resistive liquid level sensor 84, a walking auxiliary wheel 85, a stopper 86 and a support spring 87; the auxiliary support rod 82 is connected to the lower surface of the monitoring platform 10 through the support spring 87, one end of the auxiliary support rod 82 is connected to the lower surface of the monitoring platform 10 through the second rotating shaft base 81, and the other end of the auxiliary support rod 82 is connected to the walking auxiliary wheel 85 through the rotating shaft, and the support spring 87 applies elastic force to the auxiliary support rod 82, so that the walking auxiliary wheel 85 can be close to the ground. The top of the resistive liquid level sensor 84 is installed on the auxiliary support rod through the stopper 86, and the anti-collision protection rod 83 is installed on one side of the movement direction of the resistive liquid level sensor 84 to protect the resistive liquid level sensor 84 from damage; the stopper 86 limits the resistive liquid level sensor 84 when the walking auxiliary wheel is close to the ground, so that the resistive liquid level sensor 84 can be vertical to the ground. At the same time, a winding machine 88 is installed on the monitoring platform 10, one end of which is connected to the auxiliary support rod 82. The winding machine 88 is controlled by the industrial computer 50 to release and wind the wire, so as to realize the lowering and retracting of the resistive liquid level sensor 84; the support spring 87 and the anti-collision protection rod 83 protect the resistive liquid level sensor 84. When the anti-collision protection rod 83 hits the bumps or ice and snow surface of the airport runway, the support spring 87 plays a buffering role to protect the resistive liquid level sensor 84 from damage. Figure 6 As shown, the moving direction of the vehicle is the direction in which the water depth detection device 80 follows the vehicle.

[0075] like Figure 6As shown, an air pump is installed on the auxiliary support rod 82, and the air pump is controlled by the industrial computer 50; a pressure sensor is installed at the bottom end of the resistive liquid level sensor 84, and when the resistive liquid level sensor 84 contacts the ground, the pressure sensor detects data; the walking auxiliary wheel 85 adopts a vacuum tire. In the initial state, when the walking auxiliary wheel is close to the ground, the resistive liquid level sensor 84 is still a certain distance away from the airport runway surface, and the liquid level of the accumulated water cannot be measured specifically. When it is necessary to lower the resistive liquid level sensor to monitor the water accumulation on the airport runway surface, the winding machine slowly unwinds the wire so that the auxiliary walking wheel 85 is close to the ground, and the resistive liquid level sensor 84 is not in the position to measure the liquid level. At this time, the industrial computer 50 controls the air pump to deflate the auxiliary walking wheel 85, and the auxiliary walking wheel 85 gradually shrinks. The bottom end of the resistive liquid level sensor 84 gradually contacts the road surface. When the pressure sensor just detects a value, it is determined that the resistive liquid level sensor 84 is grounded at this time. At the same time, the industrial computer 50 controls the air pump to inflate the auxiliary walking wheel 85, so that the resistive liquid level sensor rises a certain distance. This distance can be controlled by calculation to a fixed value, such as 1mm, 2mm or other values, to ensure that the resistive liquid level sensor 84 can work normally. At this time, the resistive liquid level sensor 84 can detect the depth of water accumulation, and the vehicle can be operated to detect the depth of water accumulation at one end of the runway surface, and multiple data values ​​are measured to ensure the accurate value of the water accumulation depth.

[0076] In order to ensure that the resistive liquid level sensor 84 cannot be grounded when the auxiliary walking wheel 85 follows the movement of the vehicle, to avoid the bottom of the resistive liquid level sensor 84 touching the airport runway surface or the ice and snow surface during the movement of the vehicle due to uneven air pressure of each tire of the vehicle or the snow or ice on a part of the road surface has not melted completely and causing damage, the resistive liquid level sensor 84 needs to rise a certain distance so that the resistive liquid level sensor 84 gap matches the airport runway surface.

[0077] When the airport runway surface begins to accumulate snow or ice, or when snow and ice appear at the same time, the thickness of the snow and ice on the road surface is detected; when the wide-band snow detection radar 40 detects that the thickness of the snow and ice does not exceed the threshold value H, this threshold value H can be set by itself, for example, 1 cm. When the local snow accumulation is less than about one centimeter, a snow shovel is not used to shovel the snow, because shoveling snow with less snow accumulation will not achieve the effect of completely clearing the snow and will also waste manpower and material resources. Usually, the staff is notified to spray snow melting agents to clear the snow, which can achieve the effect of completely clearing the snow; the snow shovel 72 in the airport runway pavement cleaning device 70 is in a retracted state and does not shovel snow; at this time, the temperature sensor monitors the temperature of the airport runway surface. The temperature sensor is an infrared imaging temperature sensor that measures the temperature of the road surface. Only when the temperature of the road surface rises above 0 degrees Celsius will the ice and snow melt. When the temperature is higher than 0 degrees Celsius, the water depth detection device 80 lowers the resistive liquid level sensor 84 to detect the depth of the accumulated water caused by the melted ice and snow, and turns off the wide-band snow-detecting radar 40. When the ambient temperature is not higher than 0 degrees Celsius, the water depth detection device 80 retracts the resistive liquid level sensor 84 and turns on the wide-band snow-detecting radar 40. The specific implementation process is controlled by the industrial computer 50.

[0078] When the wideband snow detection radar 40 detects that the thickness of ice and snow exceeds the threshold value H, the snow cannot be completely and quickly cleared by spraying the snow melting agent alone. Therefore, it is necessary to shovel the snow first and then spray the snow melting agent to completely clear the snow. The snow shovel 72 in the airport runway pavement cleaning device 70 is in an extended state to shovel snow. At this time, the temperature sensor monitors the temperature of the airport runway pavement. When the temperature is higher than 0 degrees Celsius, the water depth detection device 80 lowers the resistive liquid level sensor 84 to detect the depth of the water melted by ice and snow, turns off the wideband snow detection radar 40, and switches the snow shovel 72 in the airport runway pavement cleaning device 70 to the retracted state; when the ambient temperature is higher than 0 degrees Celsius, the water depth detection device 80 retracts the resistive liquid level sensor 84 and turns on the wideband snow detection radar 40. The specific implementation process is controlled by the industrial control computer 50.

[0079] like Figure 4-6 As shown, when the water depth detection device 80 lowers the resistive liquid level sensor 84, the resistive liquid level sensor 84 is as vertical as possible to the airport runway surface, and the radar signal propagation direction of the wide-band snow detection radar 40 is perpendicular to the airport runway surface. Considering that the warning depth of water accumulation on the airport runway is 3mm, the resistive liquid level sensor 84 is used to measure the water depth; the conductive properties of the liquid and the relationship between resistance and liquid level are used to determine the height of the liquid level by measuring the resistance change in the liquid.

[0080] When it snows or the ambient temperature drops, and winter comes, the wideband snow detection radar will only operate when there is snow, and the snow shovel will work and cooperate with the resistive liquid level sensor 84 in the water depth detection device 80. When there is no snow or low temperature for a long time, such as when the temperature rises in summer, the wideband snow detection radar will not operate when there is no snow, and the snow shovel will not be used; at this time, when the vehicle is running, the ice monitors the damage or foreign matter on the ground through various sensors and millimeter wave radars on the monitoring platform, and at this time, the temperature sensor is not used to detect the temperature of the road surface to determine whether to lower or retract the resistive liquid level sensor 84 of the water depth detection device 80; at this time, the industrial camera 30 is used to collect road surface images, and the wireless communication device is used to transmit to the terminal computer to analyze whether there is water on the airport runway pavement. When there is water on the airport runway pavement, the terminal computer transmits a signal to the industrial computer to control the water depth detection device 80 to lower the resistive hydraulic sensor 84; when there is no water on the airport runway pavement, the industrial computer controls the water depth detection device 80 not to lower the resistive hydraulic sensor 84, or to retract the resistive hydraulic sensor 84.

[0081] like Figure 2 As shown, the radar relative ranging method, the millimeter wave radar in the FMCW mode measures that the propagation time t of the microwave signal in the medium is proportional to the thickness h of the medium multiplied by the speed v of the electromagnetic wave in the medium, that is, the time from transmission to reception:

[0082]

[0083]

[0084] In the formula, v x =c / n x ′c is the speed of light; n x ' is the effective actual refractive index; ε x The dielectric constant of ice or snow;

[0085]

[0086] In the formula, h a and h i are the distances of the radar in the air and in the ice and snow, and are the effective dielectric constants of air and ice and snow, respectively.

[0087] When the radar illuminates a covering such as ice or snow, the propagation time is converted into the distance between the radar and the target through different media. Take ice as an example: Under normal circumstances, when the ambient temperature is between 0 and minus 40 degrees Celsius, the refractive index of solid pure ice is 1.78; this allows the distance from the surface of the ice to the bottom of the ice to be calculated:

[0088]

[0089] The above is only a description of the preferred embodiments of the present invention. Ordinary technicians in this technical field can make several modifications and optimizations based on the above disclosure without departing from the above basic principles. These improvements and optimizations should be regarded as the understood protection scope of the present invention.

Claims

1. A method for monitoring the health status of an airport runway based on millimeter wave radar, characterized in that: The method comprises a monitoring platform (10) installed on a vehicle, a plurality of millimeter wave radars and a wide-bandwidth snow-penetrating radar (40) installed on the monitoring platform (10); the airport runway is monitored in real time by the plurality of millimeter wave radars to obtain radar data of the airport runway; and the collected radar data is filtered and pre-processed by denoising using a fractional-order monostable system variable-scale system resonance method to obtain pre-processed radar data; Based on extracting the echo energy intensity signal from the pre-processed radar data, calculating the peak-to-peak value change in the energy intensity signal, judging whether there is damage or foreign matter on the road surface, and using an industrial camera (30) to collect image data to determine the specific location of the damage or foreign matter; using a wide-bandwidth snow-detecting radar (40) to monitor the thickness of ice and snow covering the airport runway, and measuring the thickness of ice and snow by using a radar signal energy attenuation method and a radar relative ranging method; storing the collected raw data and analysis results, and issuing an early warning based on the analysis results.

2. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 1, characterized in that: The fractional-order monostable system variable-scale system resonance method includes a monostable model and a fractional-order system resonance model; the monostable model is: The fractional-order system resonance model is: Substituting the monostable model into the fractional-order system resonance model, the nonlinear system equation of the fractional-order monostable system is obtained: In the formula, α is the derivative order.

3. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 2, characterized in that: Introducing the time scale and coordinate transformation and substituting it into the nonlinear system equation of the fractional-order monostable system, we get: τ=βt,x(t)=z(τ) Where β is the scale factor and τ is the time constant; make, The nonlinear system equation of the fractional-order monostable system becomes: After the scale transformation, the period of the input signal increases from the original T to βT, and its amplitude returns to the original 1 / β; the amplitude of the radar echo signal is amplified back to the initial scale so that the echo signal achieves system resonance: The scale transformation of the above equation is used to obtain the variable scale fractional order system resonance equation under the excitation of the millimeter wave radar echo signal; In the formula, α is the derivative order, a1 is the constant term, and b1 is the nonlinear term coefficient; By adjusting the system's derivative order α, constant term a1, and nonlinear term coefficient b1, the fractional-order system can achieve the optimal output state for the millimeter-wave radar signal and realize the noise reduction processing of the millimeter-wave radar signal.

4. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 1, characterized in that: Based on the extraction of the echo energy intensity signal in the preprocessed radar data, the peak-to-peak value change in the energy intensity signal is calculated. When the millimeter-wave radar echo is significantly weakened, the airport runway pavement will be damaged by depressions or cracks, and the degree of damage to the airport runway is judged by the size of the peak-to-peak value change of the echo signal; at this time, an industrial camera is used to shoot image data of the airport runway, and the shape and location of the road damage are determined by analysis, and an early warning is issued; when the millimeter-wave radar echo is significantly enhanced, there are foreign objects or road bulges on the airport runway pavement, and the size of the foreign objects or bulges is determined by the peak-to-peak value change of the echo signal; at this time, an industrial camera is used to shoot image data of the airport runway, and the type, volume and location of the foreign objects are determined by analysis, and an early warning is issued. Notification.

5. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 1, characterized in that: The lower surface of the monitoring platform (10) is equipped with an airport runway pavement cleaning device (70) and a water accumulation depth detection device (80), and a temperature sensor is installed on the monitoring platform (10); when the wide band snow detector (40) detects that the thickness of ice and snow does not exceed a threshold value H, the snow shovel (72) in the airport runway pavement cleaning device (70) is in a retracted state and does not shovel snow; at this time, the temperature sensor monitors the temperature of the airport runway pavement, and when the temperature is higher than 0 degrees Celsius, the water accumulation depth detection device (80) lowers the resistive liquid level sensor (84) to detect the depth of the water accumulated by the melted ice and snow; when the ambient temperature is not higher than 0 degrees Celsius, the water accumulation depth detection device (80) retracts the resistive liquid level sensor (84).

6. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 5, characterized in that: When the wideband snow detection radar (40) detects that the thickness of ice and snow exceeds a threshold value H, the snow shovel (72) in the airport runway pavement cleaning device (70) is in an extended state to shovel snow; at this time, the temperature sensor monitors the temperature of the airport runway pavement; when the temperature is higher than 0 degrees Celsius, the water depth detection device (80) lowers the resistive liquid level sensor (84) to detect the depth of the accumulated water formed by the fusion of ice and snow, and switches the snow shovel (72) in the airport runway pavement cleaning device (70) to a retracted state; when the ambient temperature is higher than 0 degrees Celsius, the water depth detection device (80) retracts the resistive liquid level sensor (84).

7. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 6, characterized in that: The radar signal propagation direction of the wide-bandwidth snow-detecting radar (40) is perpendicular to the airport runway surface.

8. The method for monitoring the health status of an airport runway based on millimeter wave radar according to claim 1, characterized in that: The radar relative ranging method, the millimeter wave radar in FMCW mode measures that the propagation time t of the microwave signal in the medium is proportional to the thickness h of the medium multiplied by the speed v of the electromagnetic wave in the medium, that is, the time from transmission to reception: In the formula, v x =cn x ′c is the speed of light; n x ' is the effective actual refractive index; ε x The dielectric constant of ice or snow; In the formula, h a and h i are the distances of the radar in the air and in the ice and snow, and are the effective dielectric constants of air and ice and snow, respectively.

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