CN103208205B - Vehicle safety driving early warning method based on vehicle internet - Google Patents

Abstract

The invention discloses a vehicle safety driving early warning method based on the Internet of Vehicles. The vehicle information data is sent to the network background server through the vehicle wireless communication unit. The vehicle-mounted central processing unit compares and judges the obtained dangerous point information with its own vehicle information, calls the safe vehicle distance model to generate early warning parameters, and controls the vehicle-mounted alarm unit, vehicle-mounted display unit and electric vehicle. Control the brake system to perform pre-warning response. The advantages of the present invention are: the network background server end provides dangerous point information to the vehicle-mounted terminal, and the vehicle-mounted terminal controls the vehicle-mounted alarm unit, vehicle-mounted display unit and The braking system implements early warning response, and has the reliability and efficiency of Internet of Vehicles data communication.

Description

A vehicle safety warning method based on Internet of Vehicles

technical field

The invention relates to the technical field of intelligent traffic system and wireless communication, in particular, it is a vehicle safety driving early warning method based on Internet of Vehicles.

Background technique

In recent years, my country's transportation industry has developed vigorously, and the number of residents' car ownership has increased significantly. The subsequent road traffic problems have occurred frequently. Traffic accidents such as vehicle rear-end collisions and rollovers have increasingly attracted the attention of the government and society. Safety has become the focus of attention in the field of transportation technology.

With the rapid development of wireless data communication and mobile computing technology, network mobile terminals are extended to be applied to vehicle platforms. Based on advanced wireless communication technology and Internet of Vehicles technology, efficient data transmission and information release functions can be realized between vehicles and between vehicles and traffic control centers. At the same time, the implementation of real-time monitoring measures for vehicle networking can provide technical support for the collection of rich vehicle geographic information data. Based on wireless communication technology, the vehicle and the network background server form a wireless data transmission network, so that the vehicle-mounted terminal integrated with the mobile communication device can send back the information of its own state and surrounding environment to the network background server through the wireless network, and the traffic control center will transmit the information on the network. On the platform, multi-terminal and diversified data information is processed and fused, modeled, analyzed and calculated, shared and released safely, so that information can be used as a guiding means to guide vehicles to operate efficiently and safely on the road network.

Danger warning technology is one of the key technologies for vehicle active safety, and the existing vehicle anti-collision warning system, lane departure warning system, dangerous blind spot detection system and other vehicle active safety warning systems mostly use video image analysis technology, ultrasonic detection technology, radar Detection technology or infrared detection technology perceives the dangerous state of vehicles and roads within a short distance, so as to realize the vehicle's autonomous danger warning and safety control functions; Without the interference of the aforementioned detection technology, the vehicle cannot obtain reliable danger information. On the other hand, if the on-board hazard warning system lacks interaction with network information, the vehicle cannot perform real-time data transmission with the remote traffic control center, and the hazard warning function cannot be organically combined with functions such as remote data communication, vehicle positioning and navigation, and the vehicle becomes a Information islands cannot perceive the danger information and geographical location information in the large-scale driving area in advance, which will inevitably weaken the reliability of the vehicle's autonomous danger warning function, and also reduce the vehicle's active safety control capability.

Contents of the invention

In order to solve the above problems, the present invention proposes a vehicle safety early warning method based on the Internet of Vehicles, which is different from the traditional vehicle active safety early warning technology. Dangerous point information, road surface environment information, driver's driving preference information, vehicle's own geographic location information and vehicle driving status are effectively combined to construct a reliable critical distance for danger warning and critical distance for braking in real time. Based on the new safe driving warning model, not only the danger warning method in the form of voice and text is provided on the vehicle side, but also a real-time positioning and display of dangerous points, multi-frequency sound warning, multi-color progress bar warning and the early warning method combined with braking and braking methods; the present invention provides a vehicle safety driving early warning method based on the Internet of Vehicles, which provides a vehicle-side voice and text warning on the network background server side through the historical record data of the dangerous driving record table. Parameter remote early warning method, which effectively integrates the driver's driving history information into the current safety early warning process, making the safety early warning function more reliable. The specific method is as follows:

Step 1: The vehicle-mounted central processing unit in the vehicle-mounted terminal sends the vehicle information at the current moment to the network background server every time T1, including the geographic latitude and longitude data of the vehicle, driving speed data, and the port number of the wireless communication unit; at the same time, it sends the current vehicle information to the network background server. The date and time of the moment.

Step 2: The network background server side judges whether there is a dangerous point in the road section where the vehicle is located at the current moment;

According to the received vehicle information, the network background server can query and match the geographical longitude and latitude data of the vehicle with the road information database stored in the network background server, judge the road section where the vehicle is at the current moment, and query according to the corresponding geographic number of the road section Whether there are dangerous points on this road section, specifically:

1) If there are dangerous points on the road where the vehicle is located, the network background server will obtain the information of each dangerous point from the road information database, including the geographical longitude and latitude data of the dangerous point and the danger level of the dangerous point, and send the information of the dangerous point to the vehicle central The processing unit performs step 3 and step 5 at the same time;

2) If there is no dangerous point on the road section where the vehicle is located, return to step 1, and the network background server waits to receive the vehicle information sent by the vehicle terminal at the next moment.

Step 3: Set the parameters of vehicle voice warning signs and dangerous driving counting parameters on the network background server;

A, the network background server calculates the minimum distance value d ₀ between the vehicle and one or more dangerous points according to the current geographical longitude and latitude data of the vehicle obtained in step 1 and the dangerous point geographical longitude and latitude data in the dangerous point information obtained in step 2;

B, the network backend server side according to the vehicle-mounted wireless communication unit port number of the vehicle obtained in step 1, inquires whether there is a record of the vehicle in the dangerous driving record table corresponding to the road section in the road information database, and compares the distance between the vehicle and each dangerous point The minimum distance value d ₀ and the vehicle speed v are compared with the safety threshold d ^* of the minimum distance between the vehicle and the approaching dangerous point and the safety threshold v ^* of the vehicle speed for comparison and judgment, and then the vehicle voice warning flag parameter flag is set. And the dangerous driving count parameter counter, specifically:

The safety threshold d ^* of the minimum distance between the vehicle and each dangerous point and the safety threshold v ^* of the vehicle's driving speed are set by the network background server according to the danger level corresponding to each dangerous point. The shortest distance and driving distance between the vehicle and each dangerous point Safety thresholds d ^* and v ^* for velocities;

a. When the vehicle’s on-board wireless communication unit port number is not recorded in the dangerous driving record table, it means that the vehicle has not had a dangerous driving record in the current road section; at this time, if d ₀ ≤ ^{d *} and v ≥ v ^* , Then record the vehicle-mounted wireless communication unit port number of the vehicle in the data storage locations corresponding to the "port number", "record time" and "vehicle speed" fields in the dangerous driving record table, and the network background server end will receive the vehicle in step 1. Information sending date and time data and vehicle speed data, and record "1" in the data storage location corresponding to the "number of times of dangerous driving" field in the dangerous driving record table; set the vehicle voice warning flag parameter flag=true at the same time, dangerous driving count parameter counter=1;

If d ₀ ≤ d ^* and v<v ^* , then the network background server will not modify the dangerous driving record table, but only set the vehicle voice warning flag parameter flag=false, and the dangerous driving count parameter counter=1;

b. When the port number of the vehicle-mounted wireless communication unit has been stored in the dangerous driving record table, it means that the vehicle has a dangerous driving record in the current road section; at this time, if d ₀ ≤ d ^* and v ≥ v ^* , then the network background server sends date and time data and vehicle speed data through the received vehicle information, and updates the “record time” and “vehicle speed” fields corresponding to the current vehicle wireless communication unit port number in the dangerous driving record table. The vehicle information sends date and time data and vehicle speed, and adds 1 to the data corresponding to the "number of times of dangerous driving" field in the dangerous driving record table, and sets the vehicle voice warning flag parameter flag=true, and the dangerous driving count parameter counter is equal to the vehicle in danger The data corresponding to the field "number of times of dangerous driving" under the port number of the vehicle-mounted wireless communication unit of the current vehicle in the driving record table;

If d ₀ ≤ d ^* and v<v ^* , then the network background server sends date and time data and vehicle speed data through the received vehicle information to update the dangerous driving record table under the port number of the vehicle-mounted wireless communication unit of the current vehicle. The vehicle information corresponding to the "recording time" and "vehicle speed" fields sends date and time data and vehicle speed, and adds 1 to the data corresponding to the "dangerous driving times" field, and sets the vehicle voice warning flag parameter flag=false, and the dangerous driving count parameter The counter is equal to the data corresponding to the "Number of times of dangerous driving" field of the vehicle in the dangerous driving record table;

c. Regardless of whether there is current vehicle record information in the dangerous driving record table, if d ₀ >d ^* , the network background server will not update the dangerous driving record table, and only set the vehicle voice warning flag parameter flag=false, dangerous driving Count parameter counter=0, do not modify the dangerous driving record table.

After the network background server completes the setting of the vehicle voice warning flag parameter flag and the dangerous driving count parameter counter, proceed to step 4.

Step 4: Voice and text warnings on the vehicle side;

The network background server sends the vehicle voice warning flag parameter flag and the dangerous driving count parameter counter value to the vehicle-mounted central processing unit in the vehicle-mounted terminal, and the vehicle-mounted central processing unit according to the geographical longitude and latitude data of the dangerous point in the dangerous point information received in step 2 and the danger level, on the electronic map displayed by the on-board display unit in the vehicle-mounted terminal, the dangerous points are marked by markers, and the danger level of the dangerous points is marked by characters; The parameter counter performs corresponding voice and text message warning operations, specifically:

1. If flag=true and counter=1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to play the warning voice in a loop, and displays the warning text in the form of a text box on the electronic map displayed by the vehicle-mounted display unit;

2. If flag=true and counter>1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to control the vehicle-mounted alarm unit to play the warning voice in a loop, and displays the warning text in the form of a text box on the electronic map displayed by the vehicle-mounted display unit;

③. If flag=false and counter≥1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to display warning text in the form of a text box on the electronic map displayed on the vehicle-mounted display unit.

In the above three cases, the warning voice stops until flag=false and counter=0 or the voice warning function of the vehicle-mounted alarm unit is turned off; the warning text display time is t; when the execution process of step 3 is terminated or ended, then return to step 1.

Step 5: The car terminal performs sound warning, color progress bar warning and brake control;

The on-board central processing unit also calculates the minimum distance value d ₁ between the vehicle and one or more dangerous points in real time according to the vehicle's current geographic latitude and longitude data and dangerous point information, and judges d ₁ and the warning distance threshold set in the vehicle central processing unit d _m for comparative judgment, d _m <d ^* :

If d ₁ >d _m , return to step 5 to continue comparison and judgment;

If d ₁ ≤d _m , proceed to the following steps:

Ⅰ. Calculate the critical distance of danger warning d _warning and the critical distance of braking d _braking ;

The on-board central processing unit invokes the safe vehicle distance model according to the vehicle speed v, and calculates the critical distance of danger warning d _warning and the critical distance of braking d _braking ;

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; system</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; human</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; safe</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; system</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; human</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Among them, τ _system is the vehicle braking system coordination time parameter, the unit is s; τ _human is the driver’s braking reaction time parameter, the unit is s; d _safe is the distance compensation parameter, the unit is m; α is the braking deceleration parameter , unit: m/s ² ; v ^* is the safety threshold of vehicle speed, unit: m/s; and the parameter f in formula (1) and formula (2) is the road environment parameter, and the parameter g is the driving preference parameter, It is set by the vehicle-mounted panel unit according to the road surface conditions, weather conditions, and driver's driving preferences of the vehicle;

Ⅱ. Calculate and obtain the quantitative parameter ω of the degree of the vehicle approaching the dangerous point and the progress quantitative value x of the display warning progress bar;

The present invention defines dimensionless parameter ω to characterize the degree of vehicle approaching dangerous point, and ω is:

$\mathrm{<span\; class="notranslate">\; \&omega;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

The progress quantification parameter x of the warning progress bar is:

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \%</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Ⅲ. Control the on-board alarm unit to perform different alarm actions according to the parameter ω or control the electronic brake system in the on-board terminal to perform braking response, and control the on-board display unit to display the early warning progress bar according to the progress quantification parameter x of the early warning progress bar, specifically:

ⅰ. When ω>1, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted display unit to display the A-color progress bar according to the progress quantification value x; and the vehicle-mounted alarm unit does not perform sound alarm action; the vehicle-mounted central processing unit continues to calculate the parameter d ₁ , And compare and judge again, specifically:

If d ₁ ≤ d _m , return to sub-step I in step 5 to continue execution;

When d ₁ >d _m appears, the on-board central processing unit cancels the color progress bar and returns to step 1;

ⅱ. When 0.8<ω≤1, the vehicle-mounted alarm unit terminates the voice and text warning of the vehicle-mounted terminal in step 4; at the same time, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted display unit to display a progress bar in color B according to the progress quantization value x, and the vehicle-mounted The alarm unit sends out a 60dB, 200Hz alarm sound, and judges it based on the vehicle speed acquired in real time, specifically:

If the vehicle speed does not decrease within the time period t1 before the color B progress bar appears, that is, the driver does not take deceleration operation, the on-board central processing unit controls the vehicle electronic brake system to perform automatic deceleration until an artificial deceleration operation occurs ;

If the vehicle speed decreases during the first t1 time period after the progress bar of color B appears, that is, the driver takes a deceleration operation, the on-board alarm unit turns off the alarm sound;

If the progress bar of color B appears and the vehicle speed decreases, that is, the driver immediately takes a deceleration operation, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound;

ⅲ. When 0<ω≤0.8, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted alarm unit to display a C-color progress bar according to the progress quantification value x, and the vehicle-mounted alarm unit emits a 70dB, 500Hz alarm sound; and the vehicle-mounted central processing unit passes Judging the vehicle speed obtained in real time, specifically:

If the driving speed of the vehicle does not decrease within the period of time t2 before the color C progress bar appears, the on-board central processing unit controls the electronic brake system of the vehicle to perform an automatic deceleration action until an artificial deceleration operation occurs;

If the speed of the vehicle decreases during the first t2 time period after the color C progress bar appears, the on-board alarm unit will turn off the alarm sound;

If the C color progress bar appears, the vehicle speed decreases, that is, the driver immediately takes a deceleration operation, and the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound;

ⅳ. When ω≤0, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted alarm unit to display a C-color progress bar according to the progress quantification value x, and the vehicle-mounted alarm unit emits an alarm sound of 80dB and 1000Hz; at the same time, the vehicle-mounted central processing unit acquires The speed of the vehicle is judged, specifically:

If the driving speed of the vehicle does not decrease within the period of time t1 before the color C progress bar appears, the on-board central processing unit controls the electronic brake system of the vehicle to perform an automatic deceleration action until an artificial deceleration operation occurs;

If the driving speed of the vehicle decreases within the time period t1 before the color C progress bar appears, the vehicle-mounted alarm unit will turn off the alarm sound;

If the driver takes deceleration immediately when the C color progress bar appears, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound;

In the above steps ii, iii, and iv, when the driver takes the artificial deceleration operation, the on-board alarm unit turns off the alarm sound, and the on-board central processing unit continues to calculate d ₁ , and continues to use d ₁ and d _m to make judgments, specifically:

When d ₁ ≤ d _m , return to sub-step I in step 5;

When d ₁ >d _m appears, the vehicle-mounted central processing unit cancels the display of the color progress bar, and returns to step 1.

The advantages of the present invention are:

1. A vehicle safety early warning method based on the Internet of Vehicles of the present invention establishes a new type of vehicle safety early warning model on the vehicle terminal, and realizes the information interaction process between the vehicle terminal and the network background server for traffic safety early warning, and establishes An effective danger warning mechanism can effectively assist drivers in making driving decisions;

2. A vehicle safety warning method based on the Internet of Vehicles of the present invention can realize that when the vehicle enters a traffic accident-prone road section or an area near a road section where a traffic accident has occurred, it can provide the driver with real-time dangerous point locations and safety warning information ;

3. A vehicle safety early warning method based on the Internet of Vehicles of the present invention can take mandatory braking measures for the vehicle when the driver takes extreme measures, effectively avoiding the occurrence of potential traffic accidents, or avoiding accidents caused by accidents. Traffic accidents can cause traffic jams or even accidents, so as to effectively solve traffic safety problems.

Description of drawings

Fig. 1 is the overall flowchart of the vehicle safety driving early warning method of the present invention;

Fig. 2 is the flow chart of the vehicle voice warning sign parameter and dangerous driving counting parameter setting method in the vehicle safety driving early warning method of the present invention;

Fig. 3 is the flow chart of vehicle-mounted terminal voice and text warning method in the vehicle safety driving early warning method of the present invention;

Fig. 4 is a flow chart of the vehicle-mounted end sound warning, color progress bar warning and braking control method in the vehicle safety driving warning method of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

The vehicle safety driving early warning method based on the Internet of Vehicles of the present invention, as shown in Figure 1, is specifically realized through the following steps:

Step 1: The vehicle terminal sends vehicle information to the network server;

The vehicle-mounted central processing unit in the vehicle-mounted terminal sends the current vehicle information to the network background server every T1 interval through the vehicle-mounted wireless communication unit, including the geographic latitude and longitude data of the vehicle (obtained by the GPS communication unit), driving speed data (obtained by the wheel speed sensor ), the port number of the wireless communication unit, and at the same time send the date and time of the current moment to the network background server (that is, the date and time when the vehicle central processing unit sends the vehicle information to the network background server); the above T1 can be based on the actual application scenario of the vehicle For specific setting, for example, T1=100ms can be set.

Step 2: The network background server side judges whether there is a dangerous point in the road section where the vehicle is located at the current moment;

According to the received vehicle information, the network background server can query and match the geographical longitude and latitude data of the vehicle with the road information database stored in the network background server, judge the road section where the vehicle is at the current moment, and query according to the corresponding geographic number of the road section Whether there are dangerous points on this road section, specifically:

The above-mentioned dangerous points are divided into two categories, including fixed dangerous points and variable dangerous points; the fixed dangerous points include geographic points on curves with a radius of curvature smaller than R, and downhill slopes with a longitudinal slope greater than x% and a slope length less than L The starting point, the starting point of the upward slope whose vertical slope is greater than x'% and the slope length is less than L', the entry point of the road section passing through the residential area; the dangerous point of change includes the geographical point where there is a heavy fog obstacle on the road section, Geographical points where there are ice and snow obstacles on the road section, geographical points where there are mudslides or landslides on the road section, and geographical points where traffic accidents occur on the road section. The dangerous point information is stored in the road information database of the network background server. Among them, R, x, L, x', L' can be set according to different requirements. In the present invention, R=50m, x=5, L=150m; x'=4; L'=120m;

1) If there are dangerous points on the road section where the vehicle is located, the network background server will obtain the information of each dangerous point from the road information database, and send it to the vehicle central processing unit, and perform steps 3 and 5 at the same time; the dangerous point information includes Geographical latitude and longitude data of dangerous points and danger level of dangerous points; in the present invention, dangerous points are divided into "major dangerous points", "common dangerous points" and "slight dangerous points".

2) If there is no dangerous point on the road section where the vehicle is located, return to step 1, and the network background server waits to receive the vehicle information sent by the vehicle terminal at the next moment.

Step 3: Set the parameters of vehicle voice warning signs and dangerous driving counting parameters on the network background server;

As shown in Figure 2, it is specifically completed through the following steps:

A, the network background server calculates the minimum distance value d ₀ between the vehicle and one or more dangerous points according to the current geographical longitude and latitude data of the vehicle obtained in step 1 and the dangerous point geographical longitude and latitude data in the dangerous point information obtained in step 2;

B, the network backend server side according to the vehicle-mounted wireless communication unit port number of the vehicle obtained in step 1, inquires whether there is a record of the vehicle in the dangerous driving record table corresponding to the road section in the road information database, and compares the distance between the vehicle and each dangerous point The minimum distance value d ₀ of the vehicle and the vehicle speed v are compared with the safety threshold d ^* of the minimum distance between the vehicle and the approaching dangerous point and the safety threshold v ^* of the vehicle speed for comparison and judgment, and then the vehicle voice warning flag parameter flag is set. And the dangerous driving count parameter counter, specifically:

The safety threshold d ^* of the minimum distance between the vehicle and each dangerous point and the safety threshold v ^* of the vehicle's driving speed are set by the network background server according to the danger level corresponding to each dangerous point. The shortest distance and driving distance between the vehicle and each dangerous point Safety thresholds d ^* and v ^* for velocities. For example: if the danger level of the dangerous point approached by the vehicle is "major dangerous point", d ^* =150m, v ^* =8m/s can be set; when the danger level of the dangerous point approached by the vehicle is "ordinary dangerous point", d can be set ^* =150m, v ^* =10m/s; when the danger level of the dangerous point approached by the vehicle is "slightly dangerous point", d ^* =150m, v ^* =15m/s can be set.

a. When the vehicle’s on-board wireless communication unit port number is not recorded in the dangerous driving record table, it means that the vehicle has not had a dangerous driving record in the current road section; at this time, if d ₀ ≤ ^{d *} and v ≥ v ^* , Then record the vehicle-mounted wireless communication unit port number of the vehicle in the data storage locations corresponding to the "port number", "record time" and "vehicle speed" fields in the dangerous driving record table, and the network background server end will receive the vehicle in step 1. Information sending date and time data and vehicle speed data, and record "1" in the data storage location corresponding to the "number of times of dangerous driving" field in the dangerous driving record table; set the vehicle voice warning flag parameter flag=true at the same time, dangerous driving count parameter counter=1;

If d ₀ ≤ d ^* and v<v ^* , then the network background server will not modify the dangerous driving record table, but only set the vehicle voice warning flag parameter flag=false, and the dangerous driving count parameter counter=1;

b. When the port number of the vehicle-mounted wireless communication unit has been stored in the dangerous driving record table, it means that the vehicle has a dangerous driving record in the current road section; at this time, if d ₀ ≤ d ^* and v ≥ v ^* , then the network background server sends date and time data and vehicle speed data through the received vehicle information, and updates the “record time” and “vehicle speed” fields corresponding to the current vehicle wireless communication unit port number in the dangerous driving record table. The vehicle information sends date and time data and vehicle speed, and adds 1 to the data corresponding to the "number of times of dangerous driving" field in the dangerous driving record table, and sets the vehicle voice warning flag parameter flag=true, and the dangerous driving count parameter counter is equal to the vehicle in danger The data corresponding to the field "number of times of dangerous driving" under the port number of the vehicle-mounted wireless communication unit of the current vehicle in the driving record table.

If d ₀ ≤ d ^* and v<v ^* , then the network background server sends date and time data and vehicle speed data through the received vehicle information to update the dangerous driving record table under the port number of the vehicle-mounted wireless communication unit of the current vehicle. The vehicle information corresponding to the "recording time" and "vehicle speed" fields sends date and time data and vehicle speed, and adds 1 to the data corresponding to the "dangerous driving times" field, and sets the vehicle voice warning flag parameter flag=false, and the dangerous driving count parameter The counter is equal to the data corresponding to the "number of times of dangerous driving" field of the vehicle in the dangerous driving record table.

c. Regardless of whether there is current vehicle record information in the dangerous driving record table, if d ₀ >d ^* , the network background server will not update the dangerous driving record table, and only set the vehicle voice warning flag parameter flag=false, dangerous driving Count parameter counter=0, do not modify the dangerous driving record table.

After the network background server completes the setting of the above-mentioned vehicle voice warning flag parameter flag and the dangerous driving count parameter counter, enter step 4;

Step 4: Voice and text warnings on the vehicle side;

The network background server sends the vehicle voice warning flag parameter flag and the dangerous driving count parameter counter value to the vehicle-mounted central processing unit in the vehicle-mounted terminal, and the vehicle-mounted central processing unit according to the geographical longitude and latitude data of the dangerous point in the dangerous point information received in step 2 and the danger Level, on the electronic map displayed by the on-board display unit in the vehicle terminal, mark the dangerous point (red dot) and mark the danger level of the dangerous point; at the same time, the vehicle-mounted central processing unit also identifies the parameters according to the voice warning flag and the dangerous driving counting parameter counter carry out corresponding voice and text message warning operations, as shown in Figure 3, specifically:

①. If flag=true and counter=1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to play a warning voice in a loop to warn the driver, such as "Be careful, please slow down and drive", and display it in text on the electronic map displayed on the vehicle-mounted display unit. The warning text is displayed in the form of a box, such as "There is a dangerous point in the road ahead, please slow down!";

②, if flag=true and counter>1, then the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to control the vehicle-mounted alarm unit to play a warning voice in a loop to warn the driver, such as "Be careful, please slow down and drive", and the electronic display displayed on the vehicle-mounted display unit The map displays in the form of a text box "You have a dangerous driving record! Once again entered the dangerous warning zone ahead, please slow down!";

③. If flag=false and counter≥1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to display the warning text "There are dangerous points in the road ahead, please pay attention to safety!" in the form of a text box on the electronic map displayed on the vehicle-mounted display unit. Alert text message.

In above-mentioned three kinds of situations, warning voice stops when flag=false and counter=0 or the voice warning function of vehicle-mounted alarm unit is closed; Warning text display time is t; t can be set according to requirement, and t is 5s among the present invention . When the execution process of step 3 is terminated or ended, return to step 1.

Step 5: The car terminal performs sound warning, color progress bar warning and brake control;

As shown in Figure 4, the on-board central processing unit also calculates the minimum distance value d ₁ between the vehicle and one or more dangerous points in real time according to the vehicle’s current geographic latitude and longitude data obtained by the GPS communication unit and the dangerous point information obtained in step 2. And judge d ₁ to compare and judge with the early warning distance threshold d _m set in the vehicle central processing unit:

Since the time when the vehicle-mounted terminal sends vehicle information data is not the same as the time when the vehicle-mounted terminal receives dangerous point information, there is a time delay, and the vehicle will continue to move. The data is different from the geographic longitude and latitude data of the vehicle previously sent to the network background server, so the above d ^* is not equal to d _m ; and because the vehicle is gradually approaching the dangerous point, d _m <d ^* ;

If d ₁ >d _m , return to step 5 to continue comparison and judgment;

If d ₁ ≤d _m , proceed to the following steps:

Ⅰ. Calculate the critical distance of danger warning d _warning and the critical distance of braking d _braking ;

The on-board central processing unit invokes the safe inter-vehicle distance model according to the vehicle speed v, and calculates the critical distance of danger warning d _warning (unit: m) and the critical distance of braking d _braking (unit: m);

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; system</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; human</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; safe</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; system</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; human</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Among them, τ _system is the vehicle braking system coordination time parameter, the unit is s; τ _human is the driver’s braking reaction time parameter, the unit is s; d _safe is the distance compensation parameter, the unit is m; α is the braking deceleration parameter , unit: m/s ² ; v ^* is the safety threshold of vehicle speed, unit: m/s. The parameters α, τ _system , τ _human and d _safe can be specifically set according to the vehicle application scenario, for example: v ^* = 8m/s, α = 6m/s ² , τ _system = 0.2s, τ _human = 1s and d _safe = 5m. The parameter f in formula (1) and formula (2) is the road environment parameter, and the parameter g is the driving preference parameter, which is set by the on-board panel unit according to the road conditions, weather conditions, and driving preferences of the driver; The driver can control the vehicle respectively through the ideal road mode button, asphalt dry road mode button, asphalt wet road mode button, ice and snow road mode button, conservative driving mode button, non-conservative driving mode button and normal driving mode button on the vehicle panel unit of the vehicle terminal. The switching of f and g setting values is as follows:

Ideal road mode button corresponds to f=1; asphalt dry road mode button corresponds to f=1.5; asphalt wet road mode button corresponds to f=1.7; ice and snow road mode button corresponds to f=2; conservative driving mode button corresponds to g=1.2; non-conservative driving The mode button corresponds to g=0.8; the normal driving mode button corresponds to g=1; and when the driver does not perform any operation on the on-board unit, f=1.2 and g=1.

Ⅱ. Calculate and obtain the quantitative parameter ω of the degree of the vehicle approaching the dangerous point and the progress quantitative value x of the display warning progress bar;

The present invention defines dimensionless parameter ω to characterize the degree of vehicle approaching dangerous point, and ω is:

$\mathrm{<span\; class="notranslate">\; \&omega;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

The progress quantification parameter x of the warning progress bar is:

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \%</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Ⅲ. Control the on-board alarm unit to perform different alarm actions according to the parameter ω or control the electronic brake system in the on-board terminal to perform braking response, and control the on-board display unit to display the early warning progress bar according to the progress quantification parameter x of the early warning progress bar, specifically:

ⅰ. When ω>1, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted display unit to display a color progress bar (green progress bar) according to the progress quantification value x; and the vehicle-mounted alarm unit does not perform sound alarm action; the vehicle-mounted central processing unit continues Calculate the parameter d ₁ , and compare and judge again, specifically:

If d ₁ ≤ d _m , return to sub-step I in step 5 to continue execution;

When d ₁ >d _m appears, the on-board central processing unit cancels the color progress bar and returns to step 1;

ⅱ. When 0.8<ω≤1, the on-board alarm unit terminates the voice and text warning on the vehicle-end in step 4; at the same time, the on-board central processing unit controls the display interface of the on-board display unit to display the B-color progress bar (yellow progress bar) according to the progress quantization value x Article), and the on-board alarm unit emits a 60dB, 200Hz alarm sound, and judges based on the vehicle speed obtained in real time, specifically:

If the vehicle speed does not decrease within the time period t1 (2s) before the color B progress bar appears, that is, the driver does not take deceleration operation, the on-board central processing unit will control the vehicle electronic brake system to perform automatic deceleration until it appears Artificial deceleration operation;

If the vehicle speed decreases during the first t1 time period after the progress bar of color B appears, that is, the driver takes a deceleration operation, the on-board alarm unit turns off the alarm sound;

If the progress bar of color B appears and the vehicle speed decreases, that is, the driver immediately takes a deceleration operation, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound;

ⅲ. When 0<ω≤0.8, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted alarm unit to display a C-color progress bar (red progress bar) according to the progress quantification value x, and the vehicle-mounted alarm unit emits an alarm sound of 70dB and 500Hz; and The on-board central processing unit judges the vehicle speed obtained in real time, specifically:

If the driving speed of the vehicle does not decrease within the period of time t2 (1.5s) before the color C progress bar appears, the on-board central processing unit controls the electronic brake system of the vehicle to perform an automatic deceleration action until an artificial deceleration operation occurs;

If the vehicle speed decreases during the first t2 (1.5s) period after the color C progress bar appears, the on-board alarm unit will turn off the alarm sound;

If the C color progress bar appears, the vehicle speed decreases, that is, the driver immediately takes a deceleration operation, and the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound;

ⅳ. When ω≤0, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted alarm unit to display a C-color progress bar according to the progress quantification value x, and the vehicle-mounted alarm unit emits an alarm sound of 80dB and 1000Hz; at the same time, the vehicle-mounted central processing unit acquires The speed of the vehicle is judged, specifically:

If the driving speed of the vehicle does not decrease within the period of time t1 before the color C progress bar appears, the on-board central processing unit controls the electronic brake system of the vehicle to perform an automatic deceleration action until an artificial deceleration operation occurs;

If the driving speed of the vehicle decreases within the time period t1 before the color C progress bar appears, the vehicle-mounted alarm unit will turn off the alarm sound;

If the driver takes deceleration immediately when the C color progress bar appears, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound;

In the above steps ii, iii, and iv, when the driver takes the artificial deceleration operation, the on-board alarm unit turns off the alarm sound, and the on-board central processing unit continues to calculate d ₁ , and continues to use d ₁ and d _m to make judgments, specifically:

When d ₁ ≤ d _m , return to sub-step I in step 5;

When d ₁ >d _m appears, the vehicle-mounted central processing unit cancels the display of the color progress bar, and returns to step 1.

When a vehicle enters a traffic accident-prone road section or an area near a road section where traffic accidents have occurred, the vehicle safety driving early warning device and its early warning method of the present invention can provide the driver with real-time dangerous point locations and safety warning information, even before the driver Under extreme measures, it is possible to take mandatory braking measures on the vehicle, effectively avoiding the occurrence of potential traffic accidents, or avoiding traffic jams or even accidents caused by traffic accidents that have occurred, thereby effectively solving traffic problems. Security Question.

Claims (8)

1. A vehicle safety driving early warning method based on Internet of Vehicles, comprising: Step 1: The vehicle-mounted central processing unit in the vehicle-mounted terminal sends the vehicle information at the current moment to the network background server every time T1, including the geographic latitude and longitude data of the vehicle, driving speed data, and the port number of the wireless communication unit; at the same time, it sends the current vehicle information to the network background server. the date and time of the moment; Step 2: The network background server side judges whether there is a dangerous point in the road section where the vehicle is located at the current moment; According to the received vehicle information, the network backend server can query and match the geographical longitude and latitude data of the vehicle with the road information database stored in the network backend server, judge the road section where the vehicle is at the current moment, and query according to the corresponding geographical number of the road section Whether there are dangerous points on this road section, specifically: 1) If there are dangerous points on the road section where the vehicle is located, the network background server will obtain the information of each dangerous point from the road information database, including the geographical longitude and latitude data of the dangerous point and the danger level of the dangerous point, and send the information of the dangerous point to the vehicle central The processing unit performs step 3 and step 5 at the same time; 2) If there is no dangerous point on the road section where the vehicle is located, return to step 1, and the network background server waits to receive the vehicle information sent by the vehicle terminal at the next moment; It is characterized in that: it also includes the following steps: Step 3: Set the parameters of vehicle voice warning signs and dangerous driving counting parameters on the network background server; A, the network background server calculates the minimum distance value d ₀ between the vehicle and one or more dangerous points according to the current geographical longitude and latitude data of the vehicle obtained in step 1 and the dangerous point geographical longitude and latitude data in the dangerous point information obtained in step 2; B, the network backend server side according to the vehicle-mounted wireless communication unit port number of the vehicle obtained in step 1, inquires whether there is a record of the vehicle in the dangerous driving record table corresponding to the road section in the road information database, and compares the distance between the vehicle and each dangerous point The minimum distance value d ₀ and the vehicle speed v are compared with the safety threshold d ^* of the minimum distance between the vehicle and the approaching dangerous point and the safety threshold v ^* of the vehicle speed for comparison and judgment, and then the vehicle voice warning flag parameter flag is set. And the dangerous driving count parameter counter, specifically: The safety threshold d ^* of the minimum distance between the vehicle and each dangerous point and the safety threshold v ^* of the vehicle's driving speed are set by the network background server according to the danger level corresponding to each dangerous point. The shortest distance and driving distance between the vehicle and each dangerous point Safety thresholds d ^* and v ^* for velocities; a. When the vehicle’s on-board wireless communication unit port number is not recorded in the dangerous driving record table, it means that the vehicle has not had a dangerous driving record in the current road section; at this time, if d ₀ ≤ ^{d *} and v ≥ v ^* , Then record the vehicle-mounted wireless communication unit port number of the vehicle in the data storage locations corresponding to the "port number", "record time" and "vehicle speed" fields in the dangerous driving record table, and the network background server end will receive the vehicle in step 1. Information sending date and time data and vehicle speed data, and record "1" in the data storage location corresponding to the "number of times of dangerous driving" field in the dangerous driving record table; set the vehicle voice warning flag parameter flag=true at the same time, dangerous driving count parameter counter=1; If d ₀ ≤ d ^* and v<v ^* , the network background server does not modify the dangerous driving record table, but only sets the vehicle voice warning flag parameter flag=false, and the dangerous driving count parameter counter=1; b. When the port number of the vehicle-mounted wireless communication unit has been stored in the dangerous driving record table, it means that the vehicle has a dangerous driving record in the current road section; at this time, if d ₀ ≤ d ^* and v ≥ v ^* , then the network background server uses the received vehicle information to send date and time data and vehicle speed data, respectively updating the "record time" and "vehicle speed" fields corresponding to the current vehicle wireless communication unit port number in the dangerous driving record table. The vehicle information sends date and time data and vehicle speed, and adds 1 to the data corresponding to the "number of times of dangerous driving" field in the dangerous driving record table, and sets the vehicle voice warning flag parameter flag=true, and the dangerous driving count parameter counter is equal to the vehicle in danger The data corresponding to the field "number of times of dangerous driving" under the port number of the vehicle-mounted wireless communication unit of the current vehicle in the driving record table; If d ₀ ≤ d ^* and v < v ^* , then the network background server uses the received vehicle information to send date and time data and vehicle speed data, and respectively update the current vehicle wireless communication unit port number of the current vehicle in the dangerous driving record table The date and time data and vehicle speed of the vehicle information corresponding to the "recording time" and "vehicle speed" fields, and add 1 to the data corresponding to the "dangerous driving times" field, and set the vehicle voice warning flag parameter flag=false, dangerous driving count The parameter counter is equal to the data corresponding to the "Number of times of dangerous driving" field of the vehicle in the dangerous driving record table; c. Regardless of whether there is current vehicle record information in the dangerous driving record table, if d ₀ >d ^* , the network background server will not update the dangerous driving record table, and only set the vehicle voice warning flag parameter flag=false, dangerous driving Count parameter counter=0, do not modify the dangerous driving record table; After the network background server completes the setting of the above-mentioned vehicle voice warning flag parameter flag and the dangerous driving count parameter counter, enter step 4; Step 4: Voice and text warnings on the vehicle side; The network background server sends the vehicle voice warning flag parameter flag and the dangerous driving count parameter counter value to the vehicle central processing unit in the vehicle terminal, and the vehicle central processing unit according to the geographical longitude and latitude data of the dangerous point in the dangerous point information received in step 2 and the danger level, on the electronic map displayed by the on-board display unit in the vehicle-mounted terminal, the dangerous points are identified by markers, and the danger level of the dangerous points is identified by characters; The parameter counter performs corresponding voice and text message warning operations, specifically: 1. If flag=true and counter=1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to play the warning voice in a loop, and displays the warning text in the form of a text box on the electronic map displayed by the vehicle-mounted display unit; 2. If flag=true and counter>1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to play the warning voice in a loop, and displays the warning text in the form of a text box on the electronic map displayed by the vehicle-mounted display unit; 3. If flag=false and counter≥1, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to display warning text in the form of a text box on the electronic map displayed by the vehicle-mounted display unit; In above-mentioned three kinds of situations, warning voice stops when flag=false and counter=0 or the voice warning function of vehicle-mounted alarm unit is closed; Warning text display time is t; When the execution process of step 3 is suspended or ends, then return to step 1; Step 5: The car terminal performs sound warning, color progress bar warning and brake control; The on-board central processing unit also calculates the minimum distance value d ₁ between the vehicle and one or more dangerous points in real time according to the vehicle's current geographic latitude and longitude data and dangerous point information, and judges d ₁ and the warning distance threshold set in the vehicle central processing unit d _m for comparative judgment, d _m <d ^* : If d ₁ >d _m , return to step 5 to continue comparison and judgment; If d ₁ ≤d _m , proceed to the following steps: Ⅰ. Calculate the critical distance of danger warning d _warning and the critical distance of braking d _braking ; The on-board central processing unit invokes the safe vehicle distance model according to the vehicle speed v, and calculates the critical distance of danger warning d _warning and the critical distance of braking d _braking ; ${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; system</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; human</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; safe</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ ${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; system</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; human</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; v</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ Among them, τ _system is the vehicle braking system coordination time parameter, the unit is s; τ _human is the driver’s braking reaction time parameter, the unit is s; d _safe is the distance compensation parameter, the unit is m; α is the braking deceleration parameter , unit: m/s ² ; v ^* is the safety threshold of vehicle speed, unit is: m/s; and the parameter f in formula (1) and formula (2) is the road environment parameter, and parameter g is the driving preference parameter, It is set by the vehicle-mounted panel unit according to the road surface conditions, weather conditions, and driver's driving preferences of the vehicle; Ⅱ. Calculate and obtain the quantitative parameter ω of the degree of the vehicle approaching the dangerous point and the progress quantitative value x of the display warning progress bar; The present invention defines dimensionless parameter ω to characterize the degree of vehicle approaching dangerous point, and ω is: $<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; warning</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; braking</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ The progress quantification parameter x of the warning progress bar is: $\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \%</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$ Ⅲ. Control the on-board alarm unit to perform different alarm actions according to the parameter ω or control the electronic brake system in the on-board terminal to perform braking response, and control the on-board display unit to display the early warning progress bar according to the progress quantification parameter x of the early warning progress bar, specifically: ⅰ. When ω>1, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted display unit to display the A-color progress bar according to the progress quantification value x; and the vehicle-mounted alarm unit does not perform sound alarm action; the vehicle-mounted central processing unit continues to calculate the parameter d ₁ , And compare and judge again, specifically: If d ₁ ≤ d _m , return to sub-step I in step 5 to continue execution; When d ₁ >d _m appears, the on-board central processing unit cancels the color progress bar and returns to step 1; ⅱ. When 0.8<ω≤1, the vehicle-mounted alarm unit terminates the voice and text warning of the vehicle-mounted terminal in step 4; at the same time, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted display unit to display a progress bar in color B according to the progress quantization value x, and the vehicle-mounted The alarm unit sends out a 60dB, 200Hz alarm sound, and judges it based on the vehicle speed acquired in real time, specifically: If the vehicle speed does not decrease within the time period t1 before the color B progress bar appears, that is, the driver does not take deceleration operation, the on-board central processing unit controls the vehicle electronic brake system to perform automatic deceleration until an artificial deceleration operation occurs ; If the vehicle speed decreases during the first t1 time period after the progress bar of color B appears, that is, the driver takes a deceleration operation, the on-board alarm unit turns off the alarm sound; If the progress bar of color B appears and the vehicle speed decreases, that is, the driver immediately takes a deceleration operation, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound; ⅲ. When 0<ω≤0.8, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted alarm unit to display a C-color progress bar according to the progress quantification value x, and the vehicle-mounted alarm unit emits a 70dB, 500Hz alarm sound; and the vehicle-mounted central processing unit passes Judging the vehicle speed obtained in real time, specifically: If the driving speed of the vehicle does not decrease within the period of time t2 before the color C progress bar appears, the on-board central processing unit controls the electronic brake system of the vehicle to perform an automatic deceleration action until an artificial deceleration operation occurs; If the speed of the vehicle decreases during the first t2 time period after the color C progress bar appears, the on-board alarm unit will turn off the alarm sound; If the C color progress bar appears, the vehicle speed decreases, that is, the driver immediately takes a deceleration operation, and the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound; ⅳ. When ω≤0, the vehicle-mounted central processing unit controls the display interface of the vehicle-mounted alarm unit to display a C-color progress bar according to the progress quantification value x, and the vehicle-mounted alarm unit emits an alarm sound of 80dB and 1000Hz; at the same time, the vehicle-mounted central processing unit acquires The speed of the vehicle is judged, specifically: If the driving speed of the vehicle does not decrease within the period of time t1 before the color C progress bar appears, the on-board central processing unit controls the electronic brake system of the vehicle to perform an automatic deceleration action until an artificial deceleration operation occurs; If the driving speed of the vehicle decreases within the time period t1 before the color C progress bar appears, the vehicle-mounted alarm unit will turn off the alarm sound; If the driver takes deceleration immediately when the C color progress bar appears, the vehicle-mounted central processing unit controls the vehicle-mounted alarm unit to turn off the alarm sound; In steps ii, iii, and iv, when the driver takes an artificial deceleration operation, the on-board alarm unit turns off the alarm sound, and the on-board central processing unit continues to calculate d ₁ , and continues to use d ₁ and d _m to make judgments, specifically: When d ₁ ≤ d _m , return to sub-step I in step 5; When d ₁ >d _m appears, the vehicle-mounted central processing unit cancels the display of the color progress bar, and returns to step 1. 2. A vehicle safety early warning method based on Internet of Vehicles as claimed in claim 1, wherein: said dangerous points are divided into two categories, including fixed dangerous points and variable dangerous points; wherein, fixed dangerous points include curvature radius The geographical point on the curve less than R, the downhill starting point where the longitudinal slope of the downhill is greater than x% and the slope length is less than L, the uphill starting point where the uphill longitudinal slope is greater than x'% and the slope length is less than L', The entry points of road sections that pass through densely populated areas; changing dangerous points include geographical points on road sections with heavy fog obstacles, geographical points on road sections with ice and snow obstacles, geographical points on road sections with mudslides or landslides, and traffic accidents on road sections. geographic point. 3 . A vehicle safety warning method based on Internet of Vehicles according to claim 2 , wherein: said R=50m, x=5, L=150m; x'=4; L'=120m. 4. A vehicle safety early warning method based on Internet of Vehicles as claimed in claim 2, characterized in that: the danger levels of the danger points are major danger points, common danger points and mild danger points; and the major danger points correspond to Set d ^* = 150m, v ^* = 8m/s; set d ^* = 150m, v ^* = 10m/s for common dangerous points; set d ^* = 150m, v ^* = 15m/s for mild dangerous points. 5 . A vehicle safety warning method based on Internet of Vehicles according to claim 1 , characterized in that: said T1 is specifically set according to vehicle application scenarios, and T1 = 100 ms. 6. A vehicle safety warning method based on Internet of Vehicles as claimed in claim 1, characterized in that: the α, τ _system , τ _human and d _safe are specifically set according to the vehicle application scene, and v ^* = 8m/s , α = 6 m/s ² , τ _system = 0.2 s, τ _human = 1 s and d _safe = 5 m. 7. A kind of vehicle safe driving early warning method based on Internet of Vehicles as claimed in claim 1, is characterized in that: the numerical value setting and switching of described f and g, through the ideal road mode button on the vehicle-mounted panel unit in the vehicle-mounted terminal, Asphalt dry road mode button, asphalt wet road mode button, ice and snow road mode button, conservative driving mode button, non-conservative driving mode button and normal driving mode button control; wherein, the ideal road mode button corresponds to f=1; asphalt dry road mode button Corresponding to f=1.5; asphalt wet road mode button corresponding to f=1.7; ice and snow road mode button corresponding to f=2; conservative driving mode button corresponding to g=1.2; non-conservative driving mode button corresponding to g=0.8; normal driving mode button corresponding to g= 1; and when the driver does not perform any operation on the on-board unit, f=1.2, g=1. 8 . A vehicle safety warning method based on Internet of Vehicles according to claim 1 , wherein: said t1>t2; t1 is 2s, and t2 is 1.5s.