A method and system for early warning of deicing and snowmelt on cold-region highways

Abstract

The present invention relates to a deicing and snow-melting and early warning method for cold-region highways, comprising the following steps: step one, collecting road condition data, using ultrasonic waves to detect the road surface state, emitting ultrasonic waves, and judging the road surface state according to the different root mean square voltage values ​​of the reflected ultrasonic echoes; step two, collecting vehicle static data and dynamic data; calculating traffic state information according to vehicle dynamic data, and determining the vehicle speed limit. The present invention can obtain traffic flow information and vehicle state information comprehensively and in real time by adopting a vehicle-road collaborative method, and can obtain a more accurate road ice and snow state by combining the use of ultrasonic detectors, and can more reasonably determine the speed limit of long downhill sections of cold-region highways. The deicing and snow-melting subsystem using microwave technology can quickly respond and clean up the ice and snow road surface, providing a safer and more comfortable driving environment for drivers, reducing the risk of traffic accidents on long downhill sections, and ensuring vehicle driving safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of smart highway facilities, and in particular relates to a method and system for deicing, snow melting and early warning for highways in cold regions. Background Art

[0002] Due to the geographical location, the road surface of cold-region highways is prone to snow accumulation, ice and other phenomena that are not conducive to driving, which reduces the road adhesion coefficient and poses a driving safety hazard. Especially on long downhill sections, vehicles need sufficient road adhesion coefficient to ensure safe braking distance, so the requirements for road conditions are higher. In the ice and snow environment, the use of intelligent de-icing and snow melting and early warning technology on long downhill sections of highways can effectively improve the driving safety of cold-region highways.

[0003] There are many existing technologies for identifying icy and snowy roads and melting snow and de-icing, such as blowing hot air and spreading snow-melting agents, but there are fewer technologies related to de-icing and snow-melting and early warning on cold-region highways. Therefore, how to realize the detection, de-icing and snow-melting and early warning of icy and snowy roads on cold-region highways is the key to reducing the occurrence of accidents. Summary of the invention

[0004] The present invention aims to solve the problem of poor driving environment and high accident risk for drivers in icy and snowy weather on cold-region highways, and further provides a method and system for deicing and snow melting and early warning on cold-region highways.

[0005] The present invention relates to a method for deicing and snow melting and early warning for cold-region expressways, comprising the following steps:

[0006] Step 1: Collect road condition data, use ultrasound to detect road condition, emit ultrasound, and judge the road condition based on the different root mean square voltage values ​​of reflected ultrasonic echoes;

[0007] Step 2: Collect static and dynamic data of the vehicle; calculate traffic status information based on the dynamic data of the vehicle and determine the vehicle speed limit value. The formula is as follows:

[0008] V SL =[V a +8+a*L+b*k+c*V w ]#(1)

[0009] Among them, V SL Indicates the speed limit value adopted, in km / h; V a represents the average speed of the vehicle, in km / h; a, b and c are the weight parameters of road surface condition, traffic density and wind speed respectively; L represents the road surface condition, 0 represents good condition, 1 represents natural snow on the road surface, 2 represents compacted snow on the road surface, and 3 represents thawed ice and snow on the road surface; k represents the traffic flow density, in vehicles / km; V wIndicates the wind speed in m / s;

[0010] Step 3: Publish information about vehicle speed limits and road conditions of ice and snow to provide early warnings to vehicles;

[0011] Step 4: Determine the operating frequency of sending ultrasonic waves according to the road surface condition information and perform microwave snow removal.

[0012] In step 1, the method for determining the road surface condition is as follows:

[0013] When ultrasonic waves are emitted to the icy and snowy road, the sound pressure formula of ultrasonic waves is as follows:

[0014]

[0015] Among them, P is the sound pressure, that is, the difference between the dynamic pressure and the static pressure of the same particle at a certain moment; A is the particle amplitude; ω is the particle vibration angular frequency; ρ is the medium density; c is the wave speed; v is the particle vibration speed;

[0016] The acoustic impedance formula of ultrasound is as follows:

[0017]

[0018] Among them, Z is the acoustic impedance, that is, the ratio of the sound pressure at any point in the ultrasonic field to the vibration velocity at that point; P is the sound pressure; ρ is the medium density; c is the wave velocity; the reflectivity of the ultrasonic wave can be expressed as shown in the following formula:

[0019]

[0020]

[0021] Among them, R represents the reflectivity; P2 is the sound pressure of the reflected wave; P1 is the sound pressure of the transmitted wave; P3 is the sound pressure of the transmitted wave; Z1 is the acoustic impedance of air; Z2 is the acoustic impedance of ice and snow on the road surface.

[0022] In step one, the state of ice and snow is identified based on the root mean square voltage value of the received ultrasonic echo. If the road surface is naturally snowed, the operating frequency of the ultrasonic wave is 2.45 GHz, and the height from the ground is 60 mm. If the road surface is compacted snow and thawed snow, the operating frequency of the ultrasonic wave is 5.8 GHz, and the height from the ground is 55 mm.

[0023] In step 2, static data includes vehicle type, maximum acceleration, maximum deceleration and vehicle equipment type; dynamic data includes vehicle position, vehicle speed and vehicle acceleration; traffic status information is calculated based on vehicle dynamic data, including traffic flow, traffic density and road section speed.

[0024] The present invention also relates to a system for implementing the deicing and snow-melting and early warning method for cold-region highways, comprising a vehicle-mounted subsystem, a roadside unit subsystem, a cloud service subsystem, a detection subsystem, an information release subsystem and a deicing and snow-melting subsystem.

[0025] The on-board subsystem obtains vehicle information and exchanges information between vehicles with the roadside unit subsystem;

[0026] The roadside unit subsystem is deployed on both sides of the long downhill section to collect traffic flow, density and average speed information; the roadside unit subsystem receives vehicle information sent by the vehicle-mounted subsystem, performs preliminary processing and integration of vehicle information and traffic flow status information, and sends it to the cloud service subsystem;

[0027] The cloud service subsystem includes a cloud server, which obtains relevant detection data information, performs relevant processing, and determines the speed limit value and the control instructions taken by each vehicle;

[0028] The cloud service subsystem also includes a cloud database for storing received data;

[0029] The detection subsystem includes a weather detector that detects weather conditions and sends the information to the cloud service subsystem;

[0030] The detection subsystem also includes an ice and snow detector, which detects ice and snow conditions on the road surface through an ultrasonic detector and sends road surface status information to the cloud service subsystem;

[0031] The information release subsystem receives the speed limit value and the road condition information ahead transmitted by the roadside unit subsystem, and makes them public;

[0032] The deicing and snow-melting subsystem includes a microwave deicing device, which starts deicing and snow-melting after detecting ice and snow on the road surface.

[0033] The present invention also relates to an ice and snow melting device for use in a cold region highway ice and snow melting and early warning system, the device comprising a cylindrical metal radiation cavity 1, a conical waveguide device 2, a magnetron 3, a lifting rod 4, a main rod 5 and a fixing device 6.

[0034] The magnetron 3 generates and transmits microwave signals. The conical waveguide device 2 is made of metal material to guide the transmission of electromagnetic waves. The cylindrical metal radiation cavity 1 radiates microwaves to the road surface after being excited by the radiation cavity. The lifting rod 4 lifts and lowers the entire deicing and snow-melting device. The main rod 5 of the deicing device has a built-in power supply, motor and signal receiving device to control the up and down movement of the lifting rod and receive the working frequency and working height sent by the cloud service subsystem. The fixing device 6 connects the lifting rod and the magnetron.

[0035] The device uses a magnetron as a microwave oscillator tube, which is transmitted through a waveguide and a radiation cavity. The transmitting end is 55mm or 60mm from the ground and tilted downward by 45° to cover the entire road width. The frequency is 5.8GHz or 2.45GHz, and the layout spacing is 50m.

[0036] The present invention also relates to an ice and snow detector for de-icing and snow-melting and early warning systems on cold-region highways, the ice and snow detector comprising a wind speed detection device 7 for real-time monitoring of wind speed; a humidity sensor 8 for real-time monitoring of the air humidity of the surrounding environment; an ultrasonic detection probe 9 for transmitting ultrasonic waves and receiving ultrasonic echoes, and having a built-in signal processing and transmitting device for performing root mean square processing on the received echo signals to determine the road surface state, and integrating the wind speed and air humidity information, and then sending them to a cloud service subsystem; a solar panel 10 for collecting solar energy; and a battery placement box 11 for serving as a battery to power the device.

[0037] Beneficial Effects

[0038] The present invention adopts a vehicle-road collaborative approach to comprehensively and in real time acquire traffic flow information and vehicle status information, and uses an ultrasonic detector in combination to obtain a more accurate status of ice and snow on the road surface, and can more reasonably determine the speed limit on long downhill sections of cold-region highways. In addition, the de-icing and snow-melting subsystem using microwave technology can respond quickly and clear icy and snowy roads, providing drivers with a safer and more comfortable driving environment, reducing the risk of traffic accidents on long downhill sections, and ensuring vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of the cold region highway deicing and snow melting and early warning system of the present invention;

[0040] Figure 2 The present invention is a working flow chart of the deicing and snow melting and early warning system for cold region highways.

[0041] Figure 3 The figure is a schematic diagram of the structure of the ice and snow detector for cold-region highways according to the present invention.

[0042] Figure 4 The figure is a schematic diagram of the structure of the microwave deicing device for cold region highways according to the present invention. DETAILED DESCRIPTION

[0043] The following combination Figures 1 to 4 This embodiment will be described in detail.

[0044] The present invention discloses a method for deicing and snow melting and early warning for cold-region expressways, comprising the following steps:

[0045] Step 1: Collect road condition data, use ultrasound to detect road condition, and judge the road condition based on the different root mean square voltage values ​​of the reflected ultrasonic echoes; the method for judging the road condition is as follows:

[0046] When ultrasonic waves are emitted to the icy and snowy road, the sound pressure formula of ultrasonic waves is as follows:

[0047]

[0048] Among them, P is the sound pressure, that is, the difference between the dynamic pressure and the static pressure of the same particle at a certain moment; A is the particle amplitude; ω is the particle vibration angular frequency; ρ is the medium density; c is the wave speed; v is the particle vibration speed;

[0049] The acoustic impedance formula of ultrasound is as follows:

[0050]

[0051] Among them, Z is the acoustic impedance, that is, the ratio of the sound pressure at any point in the ultrasonic field to the vibration velocity at that point; P is the sound pressure; ρ is the medium density; c is the wave velocity; the reflectivity of the ultrasonic wave can be expressed as shown in the following formula:

[0052]

[0053]

[0054] Among them, R represents the reflectivity; P2 is the sound pressure of the reflected wave; P1 is the sound pressure of the transmitted wave; P3 is the sound pressure of the transmitted wave; Z1 is the acoustic impedance of air; Z2 is the acoustic impedance of ice and snow on the road surface.

[0055] The state of ice and snow is identified based on the root mean square voltage value of the received ultrasonic echo. If the road surface is naturally snowed, the operating frequency of the ultrasound is 2.45 GHz and the height from the ground is 60 mm. If the road surface is compacted snow and melted snow, the operating frequency of the ultrasound is 5.8 GHz and the height from the ground is 55 mm.

[0056] Step 2: Collect static and dynamic data of the vehicle; static data includes vehicle type, maximum acceleration, maximum deceleration and type of on-board equipment; dynamic data includes vehicle position, vehicle speed and vehicle acceleration; calculate traffic status information based on vehicle dynamic data, including traffic flow, traffic density and road section speed.

[0057] Calculate traffic status information based on vehicle dynamic data and determine vehicle speed limit value. The formula is as follows:

[0058] V SL =[V a +8+a*L+b*k+c*V w ]#(1)

[0059] Among them, V SL Indicates the speed limit value adopted, in km / h; V a represents the average speed of the vehicle, in km / h; a, b and c are the weight parameters of road surface condition, traffic density and wind speed respectively; L represents the road surface condition, 0 represents good condition, 1 represents natural snow on the road surface, 2 represents compacted snow on the road surface, and 3 represents thawed ice and snow on the road surface; k represents the traffic flow density, in vehicles / km; V w Indicates the wind speed in m / s;

[0060] Step 3: Publish information about vehicle speed limits and road conditions of ice and snow to provide early warnings to vehicles;

[0061] Step 4: Determine the operating frequency of sending ultrasonic waves according to the road surface condition information and perform microwave snow removal.

[0062] like Figure 1 As shown, the cold region highway deicing and snow melting and early warning system of the present invention includes a vehicle-mounted subsystem, a roadside unit subsystem, a cloud service subsystem, a detection subsystem, a deicing and snow melting subsystem and an information release subsystem. The entire system uses LPWAD technology to interconnect the various subsystems and uses LoRa as the wireless communication protocol of the entire system.

[0063] Infrastructure shall be laid out within 500m before and after the long downhill section of cold-region expressways; roadside unit subsystems shall be laid out at intervals of 100m from 500m on the right before the downhill to the start of the downhill and from 500m on the left after the end of the downhill; variable speed limit signs shall be laid out 50m away from the start of the downhill and the start of the uphill; de-icing and snow-melting devices shall be laid out at intervals of 50m on both sides of the long downhill section.

[0064] The on-board subsystem consists of an on-board computer, a duplex communication device that complies with the dedicated short-range communication technology standard, and auxiliary equipment. The on-board computer converts the signals from the vehicle sensors into real-time vehicle data required by the roadside unit subsystem. The communication equipment sends the vehicle's position, speed and other real-time status information to the roadside unit subsystem at a certain time period; receives control instructions from the roadside unit subsystem and guides the vehicle to drive according to the instructions; and shares information with other interactive vehicles to better grasp the following distance and lateral distance. Auxiliary equipment includes GPS navigation equipment, which provides vehicle position and speed information, uses data information for transmission to the roadside unit subsystem, and can also be displayed on the navigation screen to guide the driver's operation. The driver makes adjustments based on the control instructions obtained and his current real-time status to achieve vehicle speed control. The vehicle dynamic data that can be collected by the on-board subsystem include vehicle position, vehicle acceleration and vehicle speed;

[0065] The roadside unit subsystem is evenly arranged at an interval of 100m on the right side of the long downhill direction to collect road section information. The roadside unit subsystem consists of a small computer workstation and a communication device connected to it. The computer workstation can calculate the real-time traffic status information of the road section from the vehicle information received by the communication device, and transmit the traffic status information to the cloud service subsystem through the communication device. In addition, the communication device receives the control instructions from the cloud service subsystem and sends the control instructions to the vehicle-mounted subsystem in the long downhill area. The computer workstation must be able to process all vehicle information in the merging area in a timely manner within a certain period of time. The communication equipment needs to meet the 5.8GHz dedicated short-range communication technology standard and can achieve duplex communication requirements within a range of 1km. The traffic status information data detected by the roadside unit subsystem includes the traffic flow, average speed and density of the traffic flow in the detection area; the received control instructions, that is, the speed limit value adopted by the vehicle, are sent to the vehicle-mounted subsystem.

[0066] In the cloud service subsystem, the cloud database will store the vehicle status information and traffic status information data sent by the roadside unit subsystem, including vehicle dynamic data, including vehicle position, vehicle speed and acceleration; traffic status information data, including traffic flow, average speed of road section and traffic density. The cloud server will analyze and actively judge according to the traffic status information transmitted by the roadside unit subsystem and the road surface status information transmitted by the detection subsystem, and automatically adjust the speed limit value based on the pre-set traffic control strategy, and send the speed limit value to the variable speed limit sign, and send whether the deicing and snow melting device has started working and the working frequency to the deicing and snow melting system.

[0067] The information release subsystem includes a variable speed limit information board, which is designed in accordance with the national standards GB5768-2009 "Road Traffic Signs and Markings" and GB1883-2012 "Road Traffic Reflective Film". It can receive and display the speed limit information and road condition information released by the cloud service subsystem. The power supply system, layout, poles and base of the variable speed limit information board adopt an integrated design. The service life of the entire structural component is not less than 7 years, and the invisible parts of the entire information board have retro-reflective performance, support 4G / 5G communication interfaces, and also support short-range direct communication functions in the 5.9GHz frequency band. Dynamic data is refreshed twice per minute.

[0068] The flow chart of the whole system is as follows: Figure 2As shown in the figure, the workflow of the entire system is described. The thick lines represent data transmission, and the thin lines represent command transmission. Vehicles that arrive within the detection range of the long downhill section of the cold-region highway send their static and dynamic data to the roadside unit subsystem. The roadside unit subsystem detects the vehicle's status information data, merges the data sent by the on-board subsystem with the traffic flow status data and sends them to the cloud database; at the same time, the detection subsystem sends the detected temperature, humidity, wind speed, and road ice and snow status data to the cloud database. The cloud server uses the pre-designed control strategy and speed consistency principle based on the obtained traffic status data and road status data to determine the reasonable speed limit value, and sends the speed limit value and road status information to the information release subsystem, which displays the relevant information; at the same time, the cloud server determines whether the deicing and snow melting subsystem is working and the working frequency based on the road status information, and sends it to the deicing and snow melting subsystem.

[0069] like Figure 3 As shown, the present invention also relates to a detection device for de-icing and snow-melting and early warning systems on cold-region highways, 7 is a wind speed detection device for real-time monitoring of wind speed; 8 is a humidity sensor for real-time monitoring of air humidity in the surrounding environment; 9 is an ultrasonic detection probe, which can emit ultrasonic waves and receive ultrasonic echoes, and has a built-in signal processing and transmitting device, which can perform root mean square processing on the received echo signals to determine the road surface state, and integrate the wind speed and air humidity information, and then send them to the cloud service subsystem; 10 is a solar panel for collecting solar energy; 11 is a battery placement box.

[0070] The ice and snow detector uses the amplitude difference of ultrasonic reflected echoes to detect three types of ice and snow on long downhill sections: natural snow, compacted snow, and thawed snow. The detector emits ultrasonic waves through an ultrasonic transmitting module, and when the ultrasonic waves reach the surface of ice and snow on the road, physical phenomena such as reflection, refraction, and transmission will occur.

[0071] The sound pressure formula of ultrasonic waves is as follows:

[0072]

[0073] Among them, P is the sound pressure, that is, the difference between the dynamic pressure and the static pressure of the same particle at a certain moment; A is the particle amplitude; ω is the angular frequency of particle vibration; ρ is the medium density; c is the wave speed; v is the particle vibration speed.

[0074] The acoustic impedance formula of ultrasound is as follows:

[0075]

[0076] Among them, Z is the acoustic impedance, that is, the ratio of the sound pressure at any point in the ultrasonic field to the vibration velocity at that point; P is the sound pressure; ρ is the medium density; and c is the wave velocity.

[0077] From formula (2), it can be seen that the density of the medium is proportional to the acoustic impedance of the ultrasonic wave. The greater the difference in acoustic impedance, the lower the acoustic wave transmittance. According to the law of conservation of energy, the stronger the acoustic wave reflectivity, and vice versa. When the ultrasonic wave is emitted to the ice and snow layer on the road surface, since the density and reflectivity of different ice and snow states are different, the different ice and snow states can be analyzed and judged based on the strength, amplitude and phase of the reflected echo.

[0078] The reflectivity of ultrasound can be expressed as follows:

[0079]

[0080]

[0081] Among them, R represents the reflectivity; P2 is the sound pressure of the reflected wave; P1 is the sound pressure of the transmitted wave; P3 is the sound pressure of the transmitted wave; Z1 is the acoustic impedance of air; Z2 is the acoustic impedance of ice and snow on the road surface.

[0082] It can be seen from equations (3) and (4) that when the acoustic impedance of air and road ice and snow is almost the same, that is, the density is similar, the ultrasonic reflectivity is low and the transmittance is high. On the contrary, if the acoustic impedance of air and road ice and snow is very different, that is, the density is very different, the ultrasonic reflectivity is high and the transmittance is low. Therefore, when the ultrasonic transmitter emits ultrasonic waves vertically to the road surface at a height of 40 cm from the road surface, if the road surface is frozen, it can be seen from equation (2) that the acoustic impedance of the three ice and snow states is greater than the air acoustic impedance, so ultrasonic echoes will be generated at the interface between the road ice and snow and the air.

[0083] The three states of ice and snow can be identified based on the root mean square voltage value of the received ultrasonic echo: those below 730mv are natural snow, those between 730mv and 850mv are compacted snow, and those above 850mv are melted ice and snow.

[0084] Figure 4 As shown, the present invention also relates to an ice and snow melting device for ice and snow melting and early warning systems on cold-region highways, comprising a cylindrical metal radiation cavity 1, a conical waveguide device 2, a magnetron 3, a lifting rod 4, a main rod 5 and a fixing device 6.

[0085] The magnetron 3 generates and transmits microwave signals. The conical waveguide device 2 is made of metal material to guide the transmission of electromagnetic waves. The cylindrical metal radiation cavity 1 radiates microwaves to the road surface after being excited by the radiation cavity. The lifting rod 4 lifts and lowers the entire deicing and snow melting device. The main rod 5 of the deicing device is equipped with a power supply, a motor and a signal receiving device to control the up and down movement of the lifting rod, and receives the working frequency and working height sent by the cloud service subsystem. The fixing device 6 connects the lifting rod and the magnetron. The device uses a magnetron as a microwave oscillator tube, which is transmitted through a waveguide and a radiation cavity. The transmitting end is 55mm or 60mm from the ground and tilted downward by 45° to cover the entire road width. The frequency is 5.8GHz or 2.45GHz, and the layout spacing is 50m.

[0086] Example

[0087] Assume that the cold region expressway is a two-way four-lane expressway with a design speed of 80km / h. The longitudinal slope of the long downhill section is 4%, the slope length is 800m, and there is an emergency parking strip on the roadside. The speed limit of the front and rear roads is 60km / h, and the traffic volume is 1000 vehicles / h. A roadside unit subsystem is arranged every 100m. The main line vehicle sends its own speed of 80km / h, position information and acceleration information to the roadside unit subsystem and surrounding interactive vehicles through the on-board subsystem; the roadside unit subsystem detects that the traffic flow of the main line section is 1000 vehicles / h, the average speed is 70km / h, and the density is 12.5 vehicles / km. The roadside unit subsystem combines the detected information with the information sent by the on-board subsystem and sends it to the cloud service database. The meteorological detector of the detection subsystem detects that the wind speed is 2m / s; the ice and snow detector detects that there is natural snow on the road surface, and then the detection subsystem sends the data to the cloud database. The cloud server combines traffic flow data, road surface status data and weather data according to the following formula:

[0088] V SL =[70+8+a*1+b*12.5+c*2]

[0089] Assuming that the values ​​of a, b, and c simulated from historical data are -2, -1, and -1 respectively, the resulting V SL The maximum speed is 62km / h, and the final speed limit is 60km / h.

[0090] At this time, the cloud server sends the determined speed limit value to the information release subsystem, and the system starts working, displays a speed limit of 60km / h on the variable speed limit board, and marks the road condition as "natural snow accumulation"; at the same time, the cloud server sends the deicing and snow melting system start working signal as well as the working frequency of 2.45GHz and the height of 60mm from the ground to the deicing and snow melting subsystem, and then the subsystem starts working, adjusts the height and starts emitting microwaves to heat the road surface and remove snow.

[0091] The above contents of the present invention are only preferred embodiments of the present invention and are not intended to limit the implementation scheme of the present invention. A person skilled in the art can easily make corresponding changes or modifications based on the main concept and spirit of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope required by the claims.

Claims

1. A method for deicing and snow melting and early warning on cold-region highways, characterized in that: The steps include: Step 1: Collect road condition data, use ultrasound to detect road condition, and determine road condition based on the root mean square voltage value of the reflected ultrasonic echo; Step 2: Collect static and dynamic data of the vehicle; calculate traffic status information based on the dynamic data of the vehicle and determine the vehicle speed limit value. The formula is as follows: V SL =[V a +8+a*L+b*k+c*V w ] (1) Among them, V SL Indicates the speed limit value adopted, in km / h; V a represents the average speed of the vehicle, in km / h; a, b and c are the weight parameters of road surface condition, traffic density and wind speed respectively; L represents the road surface condition, 0 represents good condition, 1 represents natural snow on the road surface, 2 represents compacted snow on the road surface, and 3 represents thawed ice and snow on the road surface; k represents the traffic flow density, in vehicles / km; V w Indicates the wind speed in m / s; Step 3: Publish information on vehicle speed limits and road conditions of ice and snow to provide early warnings to vehicles; Step 4: Determine the operating frequency of sending ultrasonic waves according to the road surface condition information and perform microwave snow removal.

2. The cold region highway deicing and snow melting and early warning method according to claim 1 is characterized in that: In step one, three types of ice and snow conditions are identified based on the root mean square voltage value of the received ultrasonic echo: those below 730mv are natural snow, those between 730mv and 850mv are compacted snow, and those above 850mv are thawed ice and snow.

3. The cold region highway deicing and snow melting and early warning method according to claim 1 is characterized in that: In step one, the state of ice and snow is identified based on the root mean square voltage value of the received ultrasonic echo. If the road surface state is natural snow, then in step four, the operating frequency of the ultrasound is 2.45 GHz, and the height from the ground is 60 mm; if the road surface state is determined to be compacted snow and thawed snow in step one, then in step four, the operating frequency of the ultrasound is determined to be 5.8 GHz, and the height from the ground is 55 mm.

4. The cold region highway deicing and snow melting and early warning method according to claim 1 is characterized in that: In step 2, static data includes vehicle type, maximum acceleration, maximum deceleration and type of on-board equipment; dynamic data includes vehicle position, vehicle speed and vehicle acceleration; traffic status information calculated based on vehicle dynamic data includes traffic flow, traffic density and road section speed.

5. A deicing and snow-melting and early warning system for cold-region highways for implementing the deicing and snow-melting and early warning method for cold-region highways as described in any one of claims 1 to 4, comprising a vehicle-mounted subsystem, a roadside unit subsystem, a cloud service subsystem, a detection subsystem, an information release subsystem and a deicing and snow-melting subsystem.

6. The cold region highway deicing and snow melting and early warning system according to claim 5 is characterized in that: The vehicle-mounted subsystem acquires vehicle information and exchanges information between vehicles with the roadside unit subsystem; The roadside unit subsystem collects traffic flow, density and average speed information; the roadside unit subsystem receives vehicle information sent by the vehicle-mounted subsystem, performs preliminary processing and integration of vehicle information and traffic flow status information, and sends it to the cloud service subsystem; The cloud service subsystem includes a cloud server, which obtains relevant detection data information for processing and determines the speed limit value and the control instructions taken by each vehicle; The information release subsystem receives the speed limit value and the road condition information ahead transmitted by the roadside unit subsystem, and makes them public.

7. The cold region highway deicing and snow melting and early warning system according to claim 5 is characterized in that: The deicing and snow-melting subsystem comprises a microwave deicing device, which comprises a cylindrical metal radiation cavity (1), a conical waveguide device (2), a magnetron (3), a lifting rod (4), a main rod (5) and a fixing device (6).

8. The cold region highway deicing and snow melting and early warning system according to claim 7 is characterized in that: The magnetron (3) generates and transmits microwave signals. The conical waveguide device (2) is made of metal material and guides the transmission of electromagnetic waves. The cylindrical metal radiation cavity (1) radiates microwaves toward the road surface after being excited by the radiation cavity. The lifting rod (4) lifts and lowers the entire deicing and snow-melting device. The main rod (5) of the deicing device is equipped with a power supply, a motor and a signal receiving device to control the up and down movement of the lifting rod and receive the working frequency and working height sent by the cloud service subsystem. The fixing device (6) connects the lifting rod and the magnetron.

9. The cold region highway deicing and snow melting and early warning system according to claim 8, characterized in that: The microwave deicing device uses a magnetron as a microwave oscillator tube, which is transmitted through a waveguide and a radiation cavity. The transmitting end is 55mm or 60mm from the ground and tilted downward by 45° to cover the entire road width. The frequency is 5.8GHz or 2.45GHz, and the layout spacing is 50m.

10. The cold region highway deicing and snow melting and early warning system according to claim 5, characterized in that: The detection subsystem comprises an ice and snow detector, and the ice and snow detector comprises a wind speed detection device (7), a humidity sensor (8), an ultrasonic detection probe (9), a solar cell panel (10) and a battery storage box (11); The wind speed detection device (7) monitors the wind speed in real time; the humidity sensor (8) monitors the air humidity of the surrounding environment in real time; the ultrasonic detection probe (9) emits ultrasonic waves and receives ultrasonic echoes, and has a built-in signal processing and transmission device, which can perform root mean square processing on the received echo signals to determine the road surface state, and integrate the wind speed and air humidity information and send them to the cloud service subsystem; the solar panel (10) collects solar energy; and the battery storage box (11) serves as a battery to power the device.

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