A truck early warning system and early warning method under strong wind weather of a bridge section

Abstract

This invention discloses a truck early warning system for windy conditions on bridge sections, comprising: a quartz dynamic weighing module, a meteorological data acquisition module, a road adhesion coefficient acquisition module, a roadside early warning module, a power supply module, and an industrial control storage module. The quartz dynamic weighing module, meteorological data acquisition module, road adhesion coefficient acquisition module, and roadside early warning module are all connected to the power supply module via the industrial control storage module. The relevant data collected by these modules is sent to the industrial control storage module, and after data analysis and processing by the industrial control storage module, it is fed back to the roadside early warning module to provide risk warnings to truck drivers about to pass through the bridge section. Using the early warning method of this invention, trucks can identify the type of passing truck and solve for the lateral crosswind force during windy conditions on bridge sections, thereby solving for the critical rollover and sideslip speed based on the minimum axle load axle unit, thus improving driving safety.

Description

Technical Field

[0001] This invention belongs to the field of road traffic safety technology, specifically relating to a truck early warning system and method for windy weather on bridge sections. Background Technology

[0002] Over the past decade, my country's total road mileage has been increasing, and freight transport has become an important support for my country's freight industry. However, traffic accidents involving trucks have remained high for a long time.

[0003] On the other hand, bridges are crucial infrastructure in road transportation construction. The recent completion of the Hong Kong-Zhuhai-Macau Bridge, Zhangjinggao Yangtze River Bridge, and Luzhou Bridge exemplifies the important technological advancements in building a strong transportation nation. However, due to the unique geographical location of cross-river and cross-sea bridges, the river and sea areas are prone to strong winds and heavy rains, making traffic safety on bridge sections susceptible to weather factors. Adverse weather is a significant factor in traffic accidents, and strong winds caused by monsoons and typhoons are most common on cross-river and cross-sea bridge sections. Generally, considering the passage of waterborne vehicles, bridges are designed with a relatively high longitudinal height, and many bridge sections have symmetrical streamlined designs, making airflow at the wind vanes prone to separation and reattachment. The wind force acts on the bridge and passing vehicles, generating vehicle-bridge coupled vibrations. Trucks, with their large size and high center of gravity, are highly susceptible to sideslip or even rollover when subjected to lateral forces exceeding a certain threshold, leading to serious traffic accidents. Currently, many bridges lack early warning and control systems to cope with crosswinds, and many drivers do not have professional traffic safety knowledge. If a vehicle suddenly skids and becomes unstable under strong winds, the driver may be at a loss.

[0004] Numerous inventions have been developed to improve vehicle safety on bridge sections during windy weather, with application number CN201110407703.2. The invention titled "Method for Determining Safe Driving Speed ​​under Crosswinds on Expressways" calculates the safe driving speed of a vehicle by establishing a mechanical balance based on vehicle weight, road alignment, and wind speed. However, it does not analyze the safety of trucks passing under crosswinds on bridge sections during windy weather. The invention application number CN202211203436.1, titled "Method, Device, Equipment, Storage Medium, and Vehicle for Preventing Side Overturning of Semi-Trailer Tractors," involves installing sensors on the tractor to collect pressure information on both sides of the longitudinal axis of the saddle, and determining the vehicle's safe driving speed based on the pressure information. While it acknowledges the risk of rollover, it doesn't address the rollover issue caused by uneven load distribution and varying forces on different axles. Furthermore, it overlooks the fact that the cab of a large truck is connected to the body via a tow lock structure, meaning the connection between the body and the cab is not rigid. Application CN202210194402.4, concerning vehicle control methods, devices, systems, vehicles, and storage media, designs a method to calculate target torque based on crosswind speed, steering wheel position, and vehicle speed, controlling the vehicle's motor to generate a response torque to resist crosswinds. However, it doesn't resolve the issue of driver confusion caused by the lack of transparency in the interactive warning information.

[0005] Therefore, there is an urgent need to provide a system that can design a lateral safety warning system for trucks on bridge sections under windy conditions. Summary of the Invention

[0006] To address the problems in existing technologies, this invention provides a truck early warning system for windy conditions on bridge sections, comprising: a quartz dynamic weighing module, a meteorological data acquisition module, a road adhesion coefficient acquisition module, a roadside early warning module, a power supply module, and an industrial control storage module. The quartz dynamic weighing module, meteorological data acquisition module, road adhesion coefficient acquisition module, and roadside early warning module are all connected to the power supply module via the industrial control storage module. The quartz dynamic weighing module, meteorological data acquisition module, and road adhesion coefficient acquisition module send the collected data to the industrial control storage module. After data analysis and processing by the industrial control storage module, the data is fed back to the roadside early warning module to provide risk warnings to truck drivers about to pass the bridge section.

[0007] Furthermore, the quartz weighing module includes a quartz crystal sensor and a data processing controller, used to collect data on the axle load, number of axles, and vehicle speed of passing trucks. The meteorological data acquisition module includes a wind speed sensor and a wind direction sensor, used to collect crosswind data on the bridge section where trucks pass. The roadside warning module includes a roadside variable message sign and a voice device module, used to display dynamic text and voice information about road conditions to truck drivers about to pass the bridge section. The road adhesion coefficient acquisition module includes a laser remote sensing road surface condition detector, used to obtain the road friction coefficient of the bridge section under current weather conditions. The industrial control storage module includes an industrial control computer control unit and an MCU memory, used for unit analysis and storage processing of the acquired data. The power module provides electrical energy to the entire system.

[0008] Furthermore, the quartz dynamic weighing module is installed 100m before the starting section of the bridge, the meteorological data acquisition module and the road adhesion coefficient acquisition module are installed 100-300m after the starting section of the bridge, and the roadside early warning module is installed at the starting section of the bridge.

[0009] Furthermore, the quartz dynamic weighing module, meteorological data acquisition module, and road adhesion coefficient acquisition module transmit the acquired data to the industrial control storage module via RS485 or TCP / IP protocol.

[0010] Secondly, this invention provides a warning method using a truck warning system for windy conditions on bridge sections, comprising the following steps: S1. The quartz dynamic weighing module collects data on the axle load, number of axles, axle weight, wheelbase, and vehicle speed of trucks that are about to pass through the bridge section and sends it to the industrial control storage module via 485 or TCP / IP protocol. S2. The meteorological data acquisition module sends the wind direction and speed data on the bridge surface and the road condition data from the laser remote sensing road condition detector to the industrial control storage module via RS485 or TCP / IP protocol; S3. The industrial control storage module analyzes and establishes a mechanical model of the axle unit based on the collected data, taking the axle as the smallest analysis unit, and solves the critical speeds of the axle unit for sideslip and rollover, and compares them with the current driving speed of the axle. S4. Based on the critical speed of sideslip and rollover of the axle unit and the current travel speed of the axle, establish different warning level prompt rules, display the warning prompt text on the variable message sign and broadcast it to the driver through the voice prompt module, and the driver can adjust the driving speed to ensure the safety of the truck's current travel speed.

[0011] Furthermore, the specific methods for steps S1 and S2 are as follows: The total number of axles of the passing trucks is collected by the quartz dynamic weighing module. Wheelbase is , indicating that the starting point is the front of the train, the first The first axis and the second The longitudinal distance of each axis, in units of axle load is , indicating the first The weight of each shaft, in units of The vehicle's speed is ; The wind speed sensor collected 30 Average wind speed within The unit is The wind direction sensor collects the wind direction. The unit is , representing the clockwise angle with due north, the road adhesion coefficient collected by the road adhesion coefficient acquisition module is , is a constant. The collected data was transmitted using the local area network TCP / IP network protocol, in accordance with... The data is sent in the specified format to the industrial control storage module in the nearby terminal control room.

[0012] Furthermore, the specific steps for establishing the mechanical model of the axle unit in step S3 are as follows: To establish the lateral force equations for the axle elements when a truck crosses a bridge section in windy weather, we make the following assumptions to simplify the calculation: The radius of curvature of the bridge surface is assumed to be... The center of curvature is on the right side of the vehicle's travel, assuming the road slope of the bridge surface is... Assuming the angle between the direction of the starting section of the bridge and due north is 0, When the truck is traveling on the bridge, we follow the principle of maximizing the safety boundary for sideslip and rollover, and select the axle with the smallest axle load among all axle elements for analysis. The truck is traveling in the right lane, and the axle elements pass through the dynamic weighing instrument step by step to obtain the axle load value of the element with the smallest axle load. We analyzed the sensor measurement data and then analyzed the axle unit with the lowest axle load. The axle unit with the lowest axle load is subjected to the combined force of the pressure from the vehicle body and the cargo on the axle and its own weight. The force of crosswind Inertial centrifugal force The lateral force exerted by the road surface on the tires of this axle unit gas lift , According to aerodynamic theory, the force of crosswind With lateral force coefficient wind speed Wind angle The windward area of ​​an object air density Vehicle speed The lateral force on the smallest axle load element is related to parameters such as these. Represented as: (1) Pick ,set up The relationship with the wind direction angle is as follows: (2) The road surface can provide the maximum ground friction for the tires of this minimum axle load vehicle unit. The resultant force of gravity on the axle itself. Related, among which: (3) (4) This represents the road adhesion coefficient currently collected by the sensor, where the gravity of the smallest axle load unit is: (5) Let be the acceleration due to gravity, and take . Assuming the air lift force on the truck acts evenly on each axle unit, then the lift force on the axle unit with the smallest axle load is... for: (6) This represents the projected area of ​​the truck in the vertical direction. Let the air lift coefficient be: (7) The inertial centrifugal force is affected by the curvature of the bridge road. and current axle speed The influence of this means that the inertial centrifugal force experienced by this axle unit... for: (8) when At this point, the axle unit will be at risk of sideslip; otherwise, none of the axle units on the vehicle will sideslip. In this case, the critical sideslip speed of the axle unit with the lowest axle load is... The solution is: (9) Next, a critical rollover safety model for this axle unit with the minimum axle load is established, which is also subjected to lateral forces from crosswinds. Air lift in the direction of gravity Inertial centrifugal force When this axle unit is at the critical point of rollover, the wheel on one side of the axle is at the critical point of just leaving the ground. According to the torque balance, the equation is as follows: (10) in Indicates the height of the center of mass. The width of the axle unit is represented by equations (1) and (5). Substituting these equations into equation (8), the critical rollover speed of the axle unit is obtained. : (11) Current axle travel speed With critical rollover speed Critical sideslip speed Compare them.

[0013] Furthermore, the warning level in step S4 is divided into three warning levels, when the vehicle speed... When the variable message sign and voice prompt module alert the driver to a low-risk warning, no speed adjustment is necessary; when... At that time, the variable message sign and voice prompt module alert the driver to a medium-risk warning. At the same time, variable message signs and voice prompt modules alert drivers to high-risk warnings.

[0014] Compared with existing technologies, this invention targets windy sections of major bridges. It uses a dynamic weighing instrument to obtain the number of axles and axle weights of passing vehicles, taking the axle of the truck most prone to skidding and overturning as the smallest analysis unit. A meteorological detection module obtains wind speed and direction information. Based on axle load and number of axles, a simplified index table of different truck types and vehicle sizes is constructed. A simplified critical mechanical model for truck axle unit skidding and overturning is established, and the safe speed for trucks crossing the bridge is determined. Warning information is delivered through variable message signs and voice prompts, improving traffic safety for trucks operating on bridge sections in windy weather.

[0015] This invention addresses the issue of cross-sea and cross-river bridge sections being susceptible to weather influences. Crosswinds acting on the bridge cause vehicle-bridge coupled vibrations in passing trucks. When the lateral force on a truck exceeds a certain threshold, it is prone to sideslip or even rollover, potentially leading to serious traffic accidents. This invention utilizes a quartz dynamic weighing module, wind direction sensor, wind speed sensor, and road condition detector to estimate the parameters of different truck types. Using the axle unit as the smallest analysis unit, it achieves parameter estimation for the axle unit. Based on aerodynamics, a calculation model for the lateral wind force, vertical lift, and road surface force of the axle unit is established. A simplified model for the lateral critical sideslip and rollover of the axle unit on the bridge section is also established. By solving for the critical sideslip and rollover velocities of the axle unit, the safety of the truck's current speed is determined. Finally, a variable message sign and voice module are used to provide prompts to the driver. This invention overcomes the problem of existing methods treating vehicles as rigid bodies and ignoring the hinge joints of the vehicle body. This invention can classify past truck models and estimate vehicle body parameters, while also providing driver-oriented early warning prompts. It can be used as a reference for the design of systems and devices to improve truck driving safety in windy weather on cross-river and cross-sea bridge sections. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the working principle and installation of the truck early warning system of the present invention; Figure 2 This is a flowchart of the truck early warning method of the present invention; Figure 3 This is a force diagram of the present invention with the axle as the smallest unit of analysis.

[0017] Among them, 1-moving truck; 2-quartz dynamic weighing module; 3-wind direction sensor; 4-wind speed sensor; 5-road adhesion coefficient sensor; 6-industrial control storage module; 7-variable message board; 8-voice prompt module; 9-power module. Detailed Implementation

[0018] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] According to embodiments of the present invention and accompanying drawings Figure 1As shown, the quartz dynamic weighing device module 2, located 100m before the truck 1 crosses the bridge section, obtains the axle load and speed of each axle of the truck. The wind direction sensor 3 and wind speed sensor 4, located at the bridge section, collect data in a fixed format at a fixed frequency every 30 seconds. The road adhesion coefficient acquisition module 5 also collects data in a fixed format at a fixed frequency every 30 seconds. The collected data is sent to the industrial control storage module 6 via TCP / IP communication. The industrial control computer in the industrial control storage module 6 calculates and determines the safety of crossing the bridge section under the current crosswind conditions. It then displays dynamic text prompts on the variable message sign 7 and issues voice prompts to the driver through the variable message sign 7 and the voice prompt module 8. The power supply module 9 provides power to the truck 1, the quartz dynamic weighing device module 2, the wind direction sensor 3, the wind speed sensor 4, the road adhesion coefficient acquisition module 5, and the industrial control storage module 6.

[0020] According to embodiments of the present invention and accompanying drawings Figure 2 The flowchart shown is a pre-warning method of the present invention, which includes the following steps: Step 1: Install the quartz dynamic weighing module 2 approximately 100m before the bridge starting point, and bury the quartz crystal sensor in the road surface. At this point, the road trenching work is wide. 70mm, depth For a bridge deck lane width of 3.75m, a combination of 0.8m + 0.78m + 1.8m quartz crystal sensors can be used.

[0021] The quartz dynamic weighing module 2 is powered by the system's built-in power module 9 and can collect the total number of axles of passing trucks. wheelbase , indicating that the starting point is the front of the train, the first The first axis and the second The longitudinal distance of each axis, in units of axle load , indicating the first The weight of each shaft, in units of The vehicle's speed is recorded as .

[0022] Because different types of trucks have a significant impact on the lateral wind force they face when passing through bridge sections with strong crosswinds, based on field surveys and analysis of historical data collected by weighing instruments, and referring to relevant materials such as JT / T489-201, the information of truck models is artificially defined based on the number of axles and wheelbase measured by dynamic weighing instruments to roughly estimate the truck model information. Table 1 below shows the axle load and number of axles corresponding to various types of trucks. Among them, Class I and Class II trucks are mainly distinguished by the axle load of each axle load unit, while the carrying capacity of Class III, IV, V and VI trucks is related to the number of axles, and the load of each axle load unit is not obviously distinguishable, and is mainly distinguished by the total number of axles.

[0023] Table 1 shows the axle load and number of axles for various types of trucks. Step Two: 1) Install a meteorological data acquisition module and a road adhesion coefficient sensor 5 300-500m after the starting section of the bridge section. The meteorological data acquisition module includes a wind speed sensor 4 and a wind direction sensor 3, and is installed using a roadside pole mounting method, powered by the system power module 9. The wind speed sensor 4 returns the data for the preceding 30m section. Average wind speed within The data unit is The wind direction sensor 3 returns the wind direction. The data unit is , representing the clockwise angle with due north, indicates that the road surface adhesion coefficient acquisition module 5 is a laser remote sensing road condition detector, returning a constant. The above data is transmitted using the local area network TCP / IP network protocol, in accordance with... The data format is sent to the nearby terminal control room and then relayed to the industrial control computer equipment in the industrial control storage module 6 for the next step of calculation.

[0024] 2) Establish the lateral force equations for the axle elements when a truck passes over the bridge section in windy weather. To simplify the calculation, the following assumptions are made: The radius of curvature of the bridge surface is assumed to be... The center of curvature is on the right side of the vehicle's travel, assuming the road slope of the bridge surface is... Assume that the angle between the direction of the starting section of the bridge and due north is 0.

[0025] When a truck is traveling on the bridge, the principle of maximizing the safety boundary for sideslip and rollover is followed, and the axle with the smallest axle load among all axle elements is selected for analysis.

[0026] Reference Appendix Figure 3 As shown, assuming the vehicle's direction of travel is as follows: Figure 3 As indicated by the arrow at the front of the vehicle. The following content, using a 3-axle truck as an example, shows the truck traveling in the right lane. After the axle units pass through the quartz dynamic weighing module 2, assuming... We The axle unit is analyzed. The unit is subjected to the combined force of the pressure from the vehicle body and cargo on the axle and its own weight in the lateral direction. The force of crosswind Inertial centrifugal force Lateral force of the road surface on the tires of the axle unit gas lift .

[0027] According to aerodynamic theory, the force of crosswind With lateral force coefficient wind speed Wind angle The windward area of ​​an object air density Vehicle speed Related to parameters, then Lateral forces acting on the axle unit for: (1) Pick ,set up The relationship with the wind direction angle is as follows: (2) Because different truck models vary greatly in size, the size of the frontal area directly affects the magnitude of the lateral wind force. To accurately calculate the lateral wind force of the axle unit, based on the axle load measured by the quartz dynamic weighing module 2 and the estimated vehicle model data in Table 1, and after extensive research and consultation on relevant studies, a lookup table for estimating the corresponding vehicle body dimensions for each model was constructed, as shown in Table 2 below.

[0028] Table 2. Body dimensions of various types of trucks Reference Appendix Figure 3 The road surface can provide axle units Maximum ground friction of tires The resultant force of gravity on the axle itself. Related, among which: (3) (4) This represents the road adhesion coefficient currently collected by the sensor, where Gravity: (5) Let be the acceleration due to gravity, and take . Assuming the air lift force on the truck acts evenly on each axle unit, then Lift force on the unit for: (6) This represents the projected area of ​​the truck in the vertical direction. Let the air lift coefficient be: (7) The inertial centrifugal force experienced by the axle unit is affected by the curvature of the bridge road and the current vehicle speed. The inertial centrifugal force it experiences for: (8) Therefore when At that time, this axle unit There would be a risk of sideslip; otherwise, none of the axle units would sideslip. Critical sideslip speed of axle unit The solution is: (9) Next, we will build the axle unit. The critical rollover safety model is also subject to lateral forces from crosswinds. Air lift in the direction of gravity Inertial centrifugal force When the axle unit When the vehicle is on the verge of rollover, the wheel on one side of the axle is at the critical point where it is about to leave the ground. Based on the torque balance, the equation is as follows: (10) in This represents the center height of the centroid, which is approximately estimated here as half the corresponding vehicle height according to Table 2 after obtaining the types of passing vehicles. Let the width of the axle unit be represented. Substituting equations (1) and (5) into (8), we obtain the solution. Critical rollover speed of axle unit : (11) Step 4: The variable message sign 7 and voice prompt module 8 are installed on the roadside at the beginning of the bridge section and powered by the system's power module 9. After solving for the critical sideslip and rollover speed, the industrial control computer, based on the vehicle information sent by the quartz dynamic weighing module 2, refers to Table 1 to determine the vehicle type and Table 2 to index the approximate vehicle size, compares it with the current vehicle speed, and issues a warning to the driver through the variable message sign 7 and voice prompt module 8. Three warning levels are established, and when the vehicle speed... At that time, the variable information sign 7 and the voice prompt module 8 remind the driver of a low-risk warning. At that time, the variable message sign 7 and the voice prompt module 8 alert the driver to a medium-risk warning. At the same time, the variable information sign 7 and the voice prompt module 8 remind the driver of high-risk warnings.

[0029] The present invention provides the following specific embodiments to further illustrate the early warning method of the present invention.

[0030] The radius of curvature of a certain bridge section After a truck passes a dynamic weighing device installed on the road, the dynamic weighing device measures the total number of axles. =4, axle load =3800 , =4400 , =1500 , =2500 Current truck speed =75 According to Table 1, the current trucks are classified as Class IV trucks, and the axle unit analysis is as follows: According to Table 2, the height of the axle unit's center of gravity is taken. =1.625 axle width Cross-sectional area of ​​the vehicle body side =43.88 Vertical projected area =33.75 Then the weather detection module measured the current wind speed as follows: =20 Wind angle =90 Road adhesion coefficient =0.60.

[0031] Based on the mechanical model established by the invention, and according to the critical rollover and sideslip formula of the axle unit, the axle is obtained. Critical sideslip speed =22.8 Critical rollover speed V2 L3 =30.23 The current speed of the axle unit is 20.8. This represents the axle of the truck. The absence of skidding means the truck will not skid. At this point, the industrial control computer controls the variable message sign 7 at the beginning of the bridge via the roadside warning module to display "Bridge section, beware of crosswinds, please hold the steering wheel firmly," and controls the voice prompt module 8 to issue "Beware of crosswinds ahead, slow down," completing the system's perception, calculation, and warning process for this truck, and proceeding to the calculation of the next passing vehicle.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A truck warning system for a bridge section during high wind weather, characterized in that, include: Quartz dynamic weighing module, meteorological data acquisition module, road adhesion coefficient acquisition module, roadside early warning module, power supply module, industrial control storage module. The quartz dynamic weighing module, meteorological data acquisition module, road adhesion coefficient acquisition module, and roadside early warning module are all connected to the power module through the industrial control storage module. The quartz dynamic weighing module, meteorological data acquisition module, and road adhesion coefficient acquisition module send the collected relevant data to the industrial control storage module. After the data is analyzed and processed by the industrial control storage module, it is fed back to the roadside early warning module to provide risk warnings to truck drivers who are about to pass through the bridge section. The truck early warning system employs the following early warning method: S1. The quartz dynamic weighing module collects data on the axle load, number of axles, axle weight, wheelbase, and vehicle speed of trucks that are about to pass through the bridge section and sends it to the industrial control storage module via 485 or TCP / IP protocol. S2. The meteorological data acquisition module sends the wind direction and speed data on the bridge surface and the road condition data from the laser remote sensing road condition detector to the industrial control storage module via RS485 or TCP / IP protocol; S3. The industrial control storage module analyzes and establishes a mechanical model of the axle unit based on the collected data, taking the axle as the smallest analysis unit, and solves the critical speeds of the axle unit for sideslip and rollover, and compares them with the current driving speed of the axle. S4. Based on the critical speed of sideslip and rollover of the axle unit and the current travel speed of the axle, establish different warning level prompt rules, display the warning prompt text on the variable message sign and broadcast it to the driver through the voice prompt module, and the driver can adjust the driving speed to ensure the safety of the truck's current travel speed; The specific steps for establishing the mechanical model of the axle unit in step S3 are as follows: The lateral force equation of the axle unit is established when the truck passes through the bridge section in windy weather. In order to simplify the calculation, the following conditions are assumed: the road curvature radius of the bridge is , the curvature center is on the right side of the vehicle driving, the road slope of the bridge is , and the angle between the starting section of the bridge and the north direction is 0. When the truck is traveling on the bridge, we follow the principle of maximizing the safety boundary for sideslip and rollover, and select the axle with the smallest axle load among all axle elements for analysis. The truck is traveling in the right lane, and the axle elements pass through the dynamic weighing instrument step by step to obtain the axle load value of the element with the smallest axle load. We analyzed the sensor measurement data and then analyzed the axle unit with the lowest axle load. The axle unit with the lowest axle load is subjected to the combined force of the pressure from the vehicle body and the cargo on the axle and its own weight. The force of crosswind Inertial centrifugal force The lateral force exerted by the road surface on the tires of this axle unit gas lift , According to aerodynamic theory, the force of crosswind With lateral force coefficient wind speed Wind angle The windward area of ​​an object air density Vehicle speed The lateral force on the smallest axle load element is related to parameters such as these. Represented as: (1) Pick ,set up The relationship with the wind direction angle is as follows: （2） The road surface can provide the maximum ground friction for the tires of this minimum axle load vehicle unit. The resultant force of gravity on the axle itself. Related, among which: (3) (4) This represents the road adhesion coefficient currently collected by the sensor, where the gravity of the smallest axle load unit is: （5） Let be the acceleration due to gravity, and take . Assuming the air lift force on the truck acts evenly on each axle unit, then the lift force on the axle unit with the smallest axle load is... for: （6） This represents the projected area of ​​the truck in the vertical direction. Let the air lift coefficient be: （7） The inertial centrifugal force is affected by the curvature of the bridge road. and current axle speed The influence of this means that the inertial centrifugal force experienced by this axle unit... for: （8） when At this point, the axle unit will be at risk of sideslip; otherwise, none of the axle units on the vehicle will sideslip. In this case, the critical sideslip speed of the axle unit with the lowest axle load is... The solution is: （9） Next, a critical rollover safety model for this axle unit with the minimum axle load is established, which is also subjected to lateral forces from crosswinds. Air lift in the direction of gravity Inertial centrifugal force When this axle unit is at the critical point of rollover, the wheel on one side of the axle is at the critical point of just leaving the ground. According to the torque balance, the equation is as follows: （10） in Indicates the height of the center of mass. The width of the axle unit is represented by equations (1) and (5). Substituting these equations into equation (8), the critical rollover speed of the axle unit is obtained. : （11） Current axle travel speed With critical rollover speed Critical sideslip speed Compare them.

2. The truck early warning system for high wind conditions on bridge sections according to claim 1, characterized in that, The quartz dynamic weighing module includes a quartz crystal sensor and a data processing controller, used to collect data on the axle load, number of axles, and vehicle speed of passing trucks. The meteorological data acquisition module includes a wind speed sensor and a wind direction sensor, used to collect crosswind data on the bridge section where trucks pass. The roadside warning module includes a roadside variable message sign and a voice device module, used to display dynamic text and voice information about road conditions to truck drivers about to pass the bridge section. The road adhesion coefficient acquisition module includes a laser remote sensing road surface condition detector, used to obtain the road friction coefficient of the bridge section under current weather conditions. The industrial control storage module includes an industrial control computer control unit and an MCU memory, used for unit analysis and storage processing of the acquired data. The power module provides electrical energy to the entire system.

3. The truck early warning system for high winds on bridge sections according to claim 2, characterized in that, The quartz dynamic weighing module is installed 100m before the starting section of the bridge, the meteorological data acquisition module and the road adhesion coefficient acquisition module are installed 100-300m after the starting section of the bridge, and the roadside early warning module is installed at the starting section of the bridge.

4. The truck early warning system for high winds on bridge sections according to claim 1, characterized in that, The quartz dynamic weighing module, meteorological data acquisition module, and road adhesion coefficient acquisition module transmit the acquired data to the industrial control storage module via RS485 or TCP / IP protocol.

5. The truck early warning system for high winds on bridge sections according to claim 2, characterized in that, The specific methods for steps S1 and S2 are as follows: The total number of axles of the passing trucks is collected by the quartz dynamic weighing module. Wheelbase is , indicating that the starting point is the front of the train, the first The first axis and the second The longitudinal distance of each axis, in units of axle load is , indicating the first The weight of each shaft, in units of The vehicle's speed is ; The wind speed sensor collected 30 Average wind speed within The unit is The wind direction sensor collects the wind direction. The unit is , representing the clockwise angle with due north, the road adhesion coefficient collected by the road adhesion coefficient acquisition module is , is a constant. The collected data was transmitted using the local area network TCP / IP network protocol, in accordance with... The data is sent in the specified format to the industrial control storage module in the nearby terminal control room.

6. The truck early warning system for high winds on bridge sections according to claim 1, characterized in that, The warning level in step S4 is divided into three levels, depending on the vehicle speed. When the variable message sign and voice prompt module alert the driver to a low-risk warning, no speed adjustment is necessary; when... At that time, the variable message sign and voice prompt module alert the driver to a medium-risk warning. At the same time, variable message signs and voice prompt modules alert drivers to high-risk warnings.

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