CN110473400B - Safe vehicle speed prediction method, system and vehicle terminal - Google Patents

本发明公开了一种安全车速预测方法、系统以及车载终端，该方法包括：获取被测车辆在连续下坡路段的路况信息及车辆信息；获取被测车辆行驶在预设距离间隔的初始刹车鼓温度、初始坐标位置及紧急制动次数；根据路况信息、车辆信息、初始坐标位置、初始刹车鼓温度和紧急制动次数计算行驶完预设距离间隔后的第二刹车鼓温度；获取被测车辆行驶完预设距离间隔后的第二坐标位置；根据路况信息、车辆信息、第二刹车鼓温度、第二坐标位置以及预设的温度阈值计算被测车辆的安全车速；通过计算被测车辆在每一个预设距离间隔后的刹车鼓温度，再根据预设的温度阈值计算被测车辆通过后续路段的安全速度，能够使被测车辆安全高效通过连续下坡路段。

The invention discloses a safe vehicle speed prediction method, system and vehicle-mounted terminal. The method includes: acquiring road condition information and vehicle information of a vehicle under test on a continuous downhill road section; acquiring an initial brake drum temperature when the vehicle under test travels at a preset distance interval , the initial coordinate position and the number of emergency braking; calculate the temperature of the second brake drum after driving the preset distance interval according to the road condition information, vehicle information, initial coordinate position, the initial brake drum temperature and the number of emergency braking; obtain the driving of the vehicle under test The second coordinate position after the preset distance interval is completed; calculate the safe speed of the tested vehicle according to the road condition information, vehicle information, the temperature of the second brake drum, the second coordinate position and the preset temperature threshold; The temperature of the brake drum after a preset distance interval, and then calculate the safe speed of the vehicle under test passing the subsequent road section according to the preset temperature threshold value, so that the vehicle under test can pass through the continuous downhill section safely and efficiently.

Safe vehicle speed prediction method and system and vehicle-mounted terminal

Technical Field

The invention relates to the technical field of intelligent traffic, in particular to a safe vehicle speed prediction method, a safe vehicle speed prediction system and a vehicle-mounted terminal.

Background

The road continuous downhill section is easy to have a heavy traffic accident with the participation of a truck. According to survey data statistics, the load vehicle out-of-control accident is easy to cause group death and serious injury. Because the speed of the truck is unreasonable, the temperature of a brake drum of the truck reaches the safety limit temperature in the continuous downhill process, so that brake failure is caused, and finally, the truck is out of control to cause accidents. The core problem in determining the safe speed of a truck on a continuous downhill section of a highway is the temperature prediction of a truck brake drum. In the aspect of brake drum temperature prediction, a bicycle test is generally adopted at present, empirical fitting is carried out on brake drum temperature measurement test data, and a brake drum temperature prediction model is established. The existing method has two defects, on one hand, the model lacks theoretical basis, and the scientificity and the accuracy are insufficient; on the other hand, the model cannot reflect the relation between the parameters such as roads, vehicles and environments and the temperature of the brake drum, has no universal applicability and cannot automatically calculate according to the parameters acquired by the vehicle-road cooperative system in real time; therefore, reasonable suggested speed can not be given for different continuous downhill sections, and the truck can safely and efficiently pass through the continuous downhill sections.

Disclosure of Invention

In view of this, embodiments of the present invention provide a method, a system, and a vehicle-mounted terminal for predicting a safe vehicle speed, so as to solve the problem that the prior art cannot make a load-carrying vehicle safely and efficiently pass through different continuous downhill sections.

According to a first aspect, an embodiment of the present invention provides a safe vehicle speed prediction method, including: acquiring road condition information and vehicle information of a detected vehicle on a continuous downhill road section; acquiring the initial brake drum temperature, the initial coordinate position and the emergency braking times of the vehicle to be detected running at preset distance intervals; calculating the temperature of a second brake drum after the running is finished at the preset distance interval according to the road condition information, the vehicle information, the initial coordinate position, the initial brake drum temperature and the emergency braking times; acquiring a second coordinate position of the detected vehicle after the detected vehicle runs for the preset distance interval; and calculating the safe speed of the detected vehicle according to the road condition information, the vehicle information, the temperature of the second brake drum, the second coordinate position and a preset temperature threshold value.

With reference to the first aspect, in the first embodiment of the first aspect, after calculating the safe vehicle speed of the vehicle to be tested according to the road condition information, the vehicle information, the temperature of the second brake drum, the second coordinate position, and a preset temperature threshold, the method further includes: acquiring the vehicle speed limit of the continuous downhill section, and judging whether the safe vehicle speed is less than or equal to the vehicle speed limit; and when the safe vehicle speed is less than or equal to the vehicle speed limit, taking the safe vehicle speed as the suggested vehicle speed of the tested vehicle.

With reference to the first aspect, in a second aspect, when the safe vehicle speed is greater than the vehicle speed limit, the vehicle speed limit is used as a recommended vehicle speed of the vehicle under test.

With reference to the first aspect, in a third implementation manner of the first aspect, the traffic information includes: the geometrical parameters and environment of the continuous downhill section; the vehicle information includes: coordinate information and characteristic parameters of the detected vehicle; calculating the temperature of a second brake drum after the running is finished at the preset distance interval according to the road condition information, the vehicle information, the initial coordinate position, the initial brake drum temperature and the emergency braking times, and the method comprises the following steps: calculating a first heat value generated by a brake drum of the vehicle to be measured in the speed control running stage of the vehicle to be measured within the preset distance interval according to the geometric parameters, the environmental parameters, the coordinate information, the initial coordinate position and the characteristic parameters; calculating a second heat value generated when the vehicle to be detected is emergently braked within the preset distance interval according to the characteristic parameters and the emergency braking times; and calculating the temperature of the second brake drum according to the first heat value, the second heat value and the initial brake drum temperature.

With reference to the third embodiment of the first aspect, in the fourth embodiment of the first aspect, the first calorific value is calculated by the following formula:

wherein, T_cjRepresenting a first heat value generated by the brake drum of the tested vehicle in a speed control driving stage in a jth preset distance interval, n representing the number of axles of the tested vehicle, C representing the specific heat capacity of the brake drum of the tested vehicle, m' representing the weight of the brake drum of the tested vehicle, g representing the gravitational acceleration, m representing the total weight of the tested vehicle, i_jRepresents the longitudinal gradient, s, of the road in the jth predetermined distance interval_jRepresents the longitudinal slope length, C, of the road in the jth preset distance interval₁And C₂Indicating tire friction of the vehicle under testForce parameter, V_1jRepresenting the speed of the vehicle under test at the speed control step, C_DRepresenting the air resistance coefficient of the continuous downhill section, A representing the windward area of the tested vehicle, rho representing the air density of the continuous downhill section, V_wjRepresenting the ambient wind speed, h, of said continuous downhill stretch_cRepresenting the convective heat transfer coefficient of the brake drum surface of the tested vehicle, t_wj,kRepresenting the brake drum surface temperature, t, of the kth measured vehicle_fj,kRepresenting the ambient temperature at the current moment, epsilon representing the emissivity of a brake drum of the tested vehicle, C₀The blackbody radiation degree is shown, A' represents the brake drum surface area of the tested vehicle, and j is a positive integer.

With reference to the third embodiment of the first aspect, in the fifth embodiment of the first aspect, the second calorific value is calculated by the following formula;

wherein, T_ejRepresenting a second heat value generated by a brake drum of the tested vehicle in an emergency braking stage in a j preset distance interval, n represents the number of axles of the tested vehicle, C represents the specific heat capacity of the brake drum of the tested vehicle, m' represents the specific weight of the brake drum of the tested vehicle, m represents the total weight of the tested vehicle, V_1jRepresenting the speed, V, of the vehicle under test before an emergency braking phase_2jRepresenting the speed of the tested vehicle after the emergency braking stage, and j is a positive integer.

With reference to the third embodiment of the first aspect, in the sixth embodiment of the first aspect, the second brake drum temperature is calculated by the following formula:

T_j＝T_cj+N_j×T_ej+T_j-1，

wherein, T_jRepresenting a second temperature T of the brake drum after the measured vehicle runs for the jth preset distance interval_ejIndicating that the tested vehicle generates a brake drum in an emergency braking stage in the jth preset distance intervalSecond heat value, T_cjRepresenting a first heat value T generated by the brake drum in a speed control running stage of the tested vehicle in a jth preset distance interval_j-1Represents the initial brake drum temperature of the brake drum just after the tested vehicle enters the jth preset distance interval, N_jRepresenting the emergency braking times of the tested vehicle at the jth preset distance interval, wherein j is a positive integer.

According to a second aspect, an embodiment of the present invention provides a vehicle-mounted terminal, including: the vehicle speed prediction method comprises a memory and a processor, wherein the memory and the processor are connected with each other in a communication mode, the memory stores computer instructions, and the processor executes the computer instructions so as to execute the safe vehicle speed prediction method in the first aspect or any one embodiment of the first aspect.

According to a third aspect, an embodiment of the present invention provides a safe vehicle speed prediction system including: a road side module, a vehicle-mounted module and the vehicle-mounted terminal in the second aspect; the road side module comprises a road side information acquisition module, a road side positioning module and a first wireless communication module, and the vehicle-mounted module comprises a vehicle-mounted acquisition module, a memory, a vehicle-mounted positioning module and a second wireless communication module; the roadside information acquisition module is used for acquiring geometric parameters and environmental parameters of the continuous downhill road section, and the roadside positioning module is used for acquiring coordinate information of the continuous downhill road section; the first wireless communication module is respectively connected with the road side information acquisition module, the road side positioning module and the second communication module, and the road side module transmits the geometric parameters, the environmental parameters and the coordinate information to the vehicle-mounted module through the first wireless communication module; the vehicle-mounted acquisition module is used for acquiring characteristic parameters, emergency braking times and initial brake drum temperature of the detected vehicle, and the vehicle-mounted positioning module is used for acquiring the coordinate position of the detected vehicle; and the vehicle-mounted terminal is connected with the vehicle-mounted module and is used for calculating the suggested speed of the vehicle to be detected according to the geometric parameters, the environmental parameters, the coordinate information, the initial brake drum temperature, the coordinate position, the characteristic parameters and the emergency braking times.

Compared with the prior art, the invention has the following beneficial effects: calculating the temperature of the brake drum of the detected vehicle after passing through each preset distance interval according to the road condition information of the continuous downhill section, the vehicle information of the detected vehicle, the initial brake drum temperature and the emergency braking times in the preset distance interval, and then calculating the subsequent safe speed by combining a preset temperature threshold value, thereby ensuring that the temperature of the brake drum of the detected vehicle in the continuous downhill section is lower than the brake failure temperature, avoiding the problem of brake failure of the detected vehicle caused by overhigh temperature of the brake drum, and improving the safety and the passing efficiency of the vehicle when the vehicle runs the continuous downhill section; the invention calculates the safe speed of the vehicle passing through the continuous downhill road section by collecting the real-time road condition information and the vehicle information, has more accurate calculation result, and is suitable for different continuous downhill road sections.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

FIG. 1 is a block flow diagram illustrating a safe vehicle speed prediction method in an embodiment of the present invention;

FIG. 2 is a block flow diagram illustrating a safe vehicle speed prediction method in another embodiment of the present invention;

FIG. 3 is a block diagram showing the construction of a vehicle-mounted terminal in another embodiment of the present invention;

fig. 4 shows a block diagram of a safe vehicle speed prediction system in another embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The invention is suitable for predicting the safe speed of a vehicle on different continuous downhill sections, and the road side module acquires the road condition information of the continuous downhill sections and the vehicle-mounted module acquires the vehicle information of the vehicle to be detected so as to calculate the subsequent safe speed of the vehicle to be detected after the vehicle passes a preset distance interval each time, wherein the road detection module is a device arranged on a stand column of the continuous downhill sections or a cross arm of a traffic sign and is used for real-time road condition information of the continuous downhill sections.

An embodiment of the present invention provides a safe vehicle speed prediction method, as shown in fig. 1, the method includes:

step S101: acquiring road condition information and vehicle information of a detected vehicle on a continuous downhill road section; in particular by roads arranged alongside continuous downhill stretchesThe side module acquires road condition information, and the road condition information comprises: the ambient temperature t of the continuous downhill section_fjAmbient wind velocity V_wjGPS position information (X)_R，Y_R) Air density ρ and air resistance coefficient C_DAnd a geometric parameter, which is a longitudinal slope length s of the continuous downhill section_jLongitudinal slope i_jAnd altitude e_j(ii) a Acquiring GPS coordinate information (X) of the vehicle to be detected through an on-board module arranged on the vehicle to be detected_c，Y_c) And characteristic parameters including total weight m of the vehicle to be tested, vehicle speed V₁Weight m 'of brake drum, specific heat capacity C of brake drum, surface area A' of brake drum, emissivity epsilon of brake drum and blackbody radiation C₀Area A of vehicle windward, static friction force parameter C of tire friction force₁Kinetic friction parameter C₂And the number of axes n.

Step S102: acquiring the initial brake drum temperature, the initial coordinate position and the emergency braking times of a tested vehicle running at preset distance intervals; specifically, the emergency braking times N of the detected vehicle in a preset distance interval are obtained through an on-board module_jAnd the initial brake drum temperature T of the vehicle just entering the preset distance interval_j-1And initial coordinate position (X)_c,j-1，Y_c,j-1) As shown in table 1, the preset distance interval is set according to different security levels:

TABLE 1

Step S103: calculating the temperature of a second brake drum after the vehicle runs for a preset distance interval according to the road condition information, the vehicle information, the initial coordinate position, the initial brake drum temperature and the emergency braking times, specifically calculating the heat generated by the brake drum after the vehicle runs for the preset distance interval according to the road condition information of the continuous downhill road section, the vehicle information of the vehicle to be detected and the initial coordinate position, and calculating the temperature T of the initial brake drum according to the temperature T of the initial brake drum_j-1Calculating the preset distance of the tested vehicle after runningSecond brake temperature T of post-interval brake drum_j。

Step S104: acquiring a second coordinate position of the detected vehicle after the detected vehicle runs for a preset distance interval; specifically, a second coordinate position (X) of the detected vehicle after the detected vehicle runs for a preset distance interval is obtained according to a GPS positioning chip or other positioning modules in the vehicle-mounted module_c,j，Y_c,)。

Step S105: calculating the safe speed of the vehicle to be measured according to the road condition information, the vehicle information, the temperature of the second brake drum, the second coordinate position and a preset temperature threshold; specifically, the safe speed of the vehicle to be tested is calculated according to the road condition information, the vehicle information, the temperature of the second brake drum, the second coordinate position and a preset temperature threshold in the above steps, the preset temperature threshold is the temperature at which the brake drum fails, and the specific value is determined according to the brake drum of the vehicle to be tested (for example, the preset temperature threshold may be 190 °), so as to ensure that the sum of the heat of the brake drum of the vehicle to be tested on the subsequent driving section is less than the failure temperature of the brake drum.

By implementing the safe vehicle speed prediction method in the embodiment of the invention, the temperature of the brake drum at each preset distance interval after the detected vehicle finishes running is calculated according to the real-time road condition information of the continuous downhill section and the vehicle information of the detected vehicle, and the temperature of the brake drum in the subsequent running process is ensured not to exceed the temperature threshold according to the preset temperature threshold, so that the safe speed of the detected vehicle in the subsequent running is calculated, and the problem that the load-carrying vehicle can not safely and efficiently pass through different continuous downhill sections in the prior art can be solved.

Optionally, in some embodiments of the present invention, as shown in fig. 2, after step S105 in the above embodiments, the method further includes: step S106: acquiring the vehicle speed limit of the continuous downhill section, and judging whether the safe vehicle speed is less than or equal to the vehicle speed limit; step S107: when the safe vehicle speed is less than or equal to the vehicle speed limit, taking the safe vehicle speed as the suggested vehicle speed of the detected vehicle; step S108: and when the safe vehicle speed is greater than the vehicle speed limit, taking the vehicle speed limit as the suggested vehicle speed of the detected vehicle. In practical application, each road section has corresponding speed limit, the speed limit of different continuous downhill road sections is obtained through the road side module, and the magnitude of the safety speed and the speed limit calculated in the embodiment is judged, so that the most reasonable running speed of the continuous downhill road section is given, and the overspeed running of a detected vehicle is avoided.

Optionally, in some embodiments of the present invention, the traffic information includes: geometrical parameters and environmental parameters of the continuous downhill section; the vehicle information includes: coordinate information and characteristic parameters of the detected vehicle; step S103 in the above embodiment includes:

and calculating a first heat value generated by a brake drum of the tested vehicle at the speed control running stage of the tested vehicle within the preset distance interval according to the geometric parameters, the environmental parameters, the coordinate information, the initial coordinate position and the characteristic parameters. Specifically, the first heat value is calculated by the following process:

calculating the heat Q generated by kinetic energy and potential energy of the measured vehicle in the speed control driving stage_h：

Calculating the air resistance Q of the measured vehicle in the speed control driving stage_rAnd friction force Q_aHeat generation:

Q_r＝0.001m(C₁+C₂×V_1j)s_j， (2)

Q_a＝0.5C_DAρs_j(V_1j-V_wj)²， (3)

calculating the transmission Q between the brake drum and the environment of the tested vehicle in the speed control driving stage_d：

Spaced apart by a predetermined distanceAnd a Riemann integral approximate calculation unit taking one second stroke as the heat dissipation capacity of the brake drum and calculating the first heat T generated by the brake drum when the tested vehicle runs at the speed control stage_cj：

Wherein, T_cjRepresenting a first heat value generated by the brake drum of the tested vehicle in a speed control driving stage in a jth preset distance interval, n representing the number of axles of the tested vehicle, C representing the specific heat capacity of the brake drum of the tested vehicle, m' representing the weight of the brake drum of the tested vehicle, g representing the gravitational acceleration, m representing the total weight of the tested vehicle, i_jRepresents the longitudinal gradient, s, of the road in the jth predetermined distance interval_jRepresents the longitudinal slope length, C, of the road in the jth preset distance interval₁And C₂Representing a tyre friction parameter, V, of said vehicle under test_1jRepresenting the speed of the vehicle under test at the speed control step, C_DRepresenting the air resistance coefficient of the continuous downhill section, A representing the windward area of the tested vehicle, rho representing the air density of the continuous downhill section, V_wjRepresenting the ambient wind speed, h, of said continuous downhill stretch_cRepresenting the convective heat transfer coefficient of the brake drum surface of the tested vehicle, t_wj,kRepresenting the brake drum surface temperature, t, of the kth measured vehicle_fj,kRepresenting the ambient temperature at the current moment, epsilon represents the emissivity of a brake drum of the tested vehicle, C₀Representing blackbody radiation degree, A' representing the brake drum surface area of the tested vehicle, j being a positive integer, and the speed of the tested vehicle being almost unchanged, namely V, because the tested vehicle is in the speed control driving stage_1jAnd V_2jA represents an empirical coefficient, and in practical applications, the value of a is 0.7 for the front wheel brake drum a and 0.3 for the rear wheel brake drum a.

Calculating a second heat value T generated when the tested vehicle is emergently braked within a preset distance interval according to the characteristic parameters and the times of emergency braking_ej(ii) a In particular, byThe following formula is calculated:

wherein, T_ejRepresenting a second heat quantity generated by a brake drum of the tested vehicle in an emergency braking stage in a j preset distance interval, n represents the number of axles of the tested vehicle, C represents the specific heat capacity of the brake drum of the tested vehicle, m' represents the specific weight of the brake drum of the tested vehicle, m represents the total weight of the tested vehicle, and V_1jRepresenting the speed, V, of the vehicle under test before an emergency braking phase_2jRepresenting the speed of the tested vehicle after the emergency braking stage, and j is a positive integer.

Calculating the temperature of the second brake drum according to the first heat value, the second heat value and the initial brake drum temperature, and specifically calculating the temperature T of the second brake drum according to the following formula_j：

T_j＝T_cj+N_j×T_ej+T_j-1， (8)

Wherein, T_jRepresenting a second temperature T of the brake drum after the measured vehicle runs for the jth preset distance interval_ejRepresents a second heat quantity T generated by the brake drum of the tested vehicle in the emergency braking stage in the jth preset distance interval_cjRepresenting a first heat value T generated by the brake drum in a speed control running stage of the tested vehicle in a jth preset distance interval_j-1Represents the initial brake drum temperature of the brake drum just after the tested vehicle enters the jth preset distance interval, N_jRepresenting the emergency braking times of the tested vehicle at the jth preset distance interval, wherein j is a positive integer.

When the temperature T of the second brake drum is calculated after the jth preset distance interval of the tested vehicle is run_jEnsuring that the tested vehicle safely passes through the continuous downhill road section and the heat generated by the brake drum of the tested vehicle and T in the subsequent course_jThe sum of the temperature difference and the temperature T of the second brake drum is less than a preset temperature threshold (brake drum failure temperature), namely the preset temperature threshold and the temperature T of the second brake drum_jDifference of (2)Substituting the value and the remaining distance of the detected vehicle passing through the continuous downhill section into the formula (6) to obtain the safe speed of the detected vehicle, and calculating the subsequent safe vehicle speed according to the method in the embodiment after the detected vehicle runs for the (j + 1) th preset distance interval until the detected vehicle passes through the continuous downhill section.

the road side module 1 comprises a road side information acquisition module 101, a road side positioning module 102 and a first wireless communication module 103, and the vehicle-mounted module 2 comprises a vehicle-mounted acquisition module 201, a vehicle-mounted positioning module 203 and a second wireless communication module 202; the road side information acquisition module 101 is used for acquiring geometric parameters and environmental parameters of a continuous downhill road section, and the road side positioning module 102 is used for acquiring coordinate information of the continuous downhill road section; the first wireless communication module 103 is respectively connected with the roadside information acquisition module 101, the roadside positioning module 102 and the second wireless communication module 202, and the roadside module 1 transmits the geometric parameters, the environmental parameters and the coordinate information to the vehicle-mounted module 2 through the first wireless communication module 103; the vehicle-mounted acquisition module 201 is used for acquiring characteristic parameters, emergency braking times and initial brake drum temperature of the detected vehicle, and the vehicle-mounted positioning module 203 is used for acquiring the coordinate position of the detected vehicle; the vehicle-mounted terminal 3 is connected with the vehicle-mounted module 2 and used for calculating the suggested speed of the tested vehicle according to the geometric parameters, the environmental parameters, the coordinate information, the initial brake drum temperature, the coordinate position, the characteristic parameters and the emergency braking times.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic Disk, an optical Disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD) or a Solid State Drive (SSD), etc.; the storage medium may also comprise a combination of memories of the kind described above.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.

1.一种安全车速预测方法，其特征在于，包括：1. a safe vehicle speed prediction method, is characterized in that, comprises: 获取被测车辆在连续下坡路段的路况信息及车辆信息；Obtain the road condition information and vehicle information of the tested vehicle in the continuous downhill section; 获取所述被测车辆行驶在预设距离间隔的初始刹车鼓温度、初始坐标位置及紧急制动次数；Obtain the initial brake drum temperature, initial coordinate position and the number of emergency braking times of the vehicle under test driving at a preset distance interval; 根据所述路况信息、车辆信息、初始坐标位置、初始刹车鼓温度和紧急制动次数计算行驶完所述预设距离间隔后的第二刹车鼓温度；Calculate the temperature of the second brake drum after traveling the preset distance interval according to the road condition information, the vehicle information, the initial coordinate position, the initial brake drum temperature and the number of times of emergency braking; 获取所述被测车辆行驶完所述预设距离间隔后的第二坐标位置；obtaining the second coordinate position after the vehicle under test has traveled the preset distance interval; 根据所述路况信息、车辆信息、第二刹车鼓温度、第二坐标位置以及预设的温度阈值计算所述被测车辆的安全车速；Calculate the safe speed of the tested vehicle according to the road condition information, the vehicle information, the temperature of the second brake drum, the second coordinate position and the preset temperature threshold; 其中，所述路况信息包括：所述连续下坡路段的几何参数和环境参数；所述车辆信息包括：所述被测车辆的坐标信息和特征参数；Wherein, the road condition information includes: geometric parameters and environmental parameters of the continuous downhill road section; the vehicle information includes: coordinate information and characteristic parameters of the vehicle under test; 根据所述路况信息、车辆信息、初始坐标位置、初始刹车鼓温度和紧急制动次数计算行驶完所述预设距离间隔后的第二刹车鼓温度，包括：Calculate the temperature of the second brake drum after driving the preset distance interval according to the road condition information, vehicle information, initial coordinate position, initial brake drum temperature and the number of emergency braking, including: 根据所述几何参数、环境参数、坐标信息、初始坐标位置和特征参数计算所述被测车辆在所述预设距离间隔内控速行驶阶段所述被测车辆的刹车鼓产生的第一热量值；Calculate, according to the geometric parameters, environmental parameters, coordinate information, initial coordinate position and characteristic parameters, the first calorific value generated by the brake drum of the tested vehicle during the speed-controlled driving phase of the tested vehicle within the preset distance interval; 根据所述特征参数和紧急制动次数计算所述被测车辆在所述预设距离间隔内紧急制动时产生的第二热量值；Calculate the second heat value generated when the vehicle under test is emergency braking within the preset distance interval according to the characteristic parameter and the number of emergency braking times; 根据所述第一热量值、第二热量值和初始刹车鼓温度计算所述第二刹车鼓温度。The second brake drum temperature is calculated from the first heat value, the second heat value and the initial brake drum temperature. 2.根据权利要求1所述的安全车速预测方法，其特征在于，在根据所述路况信息、车辆信息、第二刹车鼓温度、第二坐标位置以及预设的温度阈值计算所述被测车辆的安全车速之后，还包括：2 . The safe vehicle speed prediction method according to claim 1 , wherein the measured vehicle is calculated according to the road condition information, vehicle information, the temperature of the second brake drum, the second coordinate position and a preset temperature threshold. 3 . After the safe speed, it also includes: 获取所述连续下坡路段的限制车速，判断所述安全车速是否小于或等于所述限制车速；Obtain the speed limit of the continuous downhill road section, and determine whether the safe speed is less than or equal to the limit speed; 当所述安全车速小于或等于所述限制车速时，将所述安全车速作为所述被测车辆的建议车速。When the safe vehicle speed is less than or equal to the limit vehicle speed, the safe vehicle speed is used as the suggested vehicle speed of the tested vehicle. 3.根据权利要求2所述的安全车速预测方法，其特征在于，当所述安全车速大于所述限制车速时，将所述限制车速作为所述被测车辆的建议车速。3 . The safe vehicle speed prediction method according to claim 2 , wherein when the safe vehicle speed is greater than the limit vehicle speed, the limit vehicle speed is used as the suggested vehicle speed of the vehicle under test. 4 . 4.根据权利要求1所述的安全车速预测方法，其特征在于，通过以下公式计算所述第一热量值：4. The safe vehicle speed prediction method according to claim 1, wherein the first calorific value is calculated by the following formula:

其中，T_cj表示所述被测车辆在第j个预设距离间隔内控速行驶阶段所述刹车鼓产生的第一热量值，n代表所述被测车辆的轴数，C表示所述被测车辆的刹车鼓比热容，m′表示所述被测车辆的刹车鼓重量，g表示重力加速度，m表示所述被测车辆的总重，i_j表示第j个预设距离间隔内道路的纵坡坡度，s_j表示第j个预设距离间隔内道路的纵坡长度，C₁和C₂表示所述被测车辆的轮胎摩擦力参数，V_1j表示所述被测车辆在控速行驶阶段的速度，C_D表示所述连续下坡路段的空气阻力系数，A表示所述被测车辆的迎风面积，ρ表示所述连续下坡路段的空气密度，V_wj表示所述连续下坡路段的环境风速，h_c表示所述被测车辆的刹车鼓表面对流传热系数，t_wj，k表示第k个所述被测车辆的刹车鼓表面温度，t_fj，k表示当前时刻的环境温度，ε表示所述被测车辆的刹车鼓发射率，C₀表示黑体辐射度，A′表示所述被测车辆的刹车鼓表面积，j为正整数。Wherein, T _cj represents the first heat value generated by the brake drum during the speed-controlled driving of the vehicle under test within the jth preset distance interval, n represents the number of axles of the vehicle under test, and C represents the number of axles of the vehicle under test. The specific heat capacity of the brake drum of the vehicle, m' represents the weight of the brake drum of the tested vehicle, g represents the acceleration of gravity, m represents the total weight of the tested vehicle, _ij represents the longitudinal slope of the road within the jth preset distance interval Slope, s _j represents the longitudinal slope length of the road within the jth preset distance interval, C ₁ and C ₂ represent the tire friction parameters of the tested vehicle, and V _1j represents the measured vehicle’s speed in the speed control phase. speed, C _D represents the air resistance coefficient of the continuous downhill road section, A represents the windward area of the tested vehicle, ρ represents the air density of the continuous downhill road section, _Vwj represents the ambient wind speed of the continuous downhill road section, h _c represents the convective heat transfer coefficient of the brake drum surface of the vehicle under test, t _{wj, k} represents the surface temperature of the brake drum of the k-th vehicle under test, t _{fj, k} represents the ambient temperature at the current moment, and ε represents the The emissivity of the brake drum of the vehicle to be tested, C ₀ represents the black body radiation, A' represents the surface area of the brake drum of the vehicle to be tested, and j is a positive integer. 5.根据权利要求1所述的安全车速预测方法，其特征在于，通过以下公式计算所述第二热量值；5 . The safe vehicle speed prediction method according to claim 1 , wherein the second calorific value is calculated by the following formula; 6 .

其中，T_ej表示所述被测车辆在第j个预设距离间隔内紧急制动阶段刹车鼓产生的第二热量值，n代表所述被测车辆的轴数，C表示所述被测车辆的刹车鼓比热容，m′表示所述被测车辆的刹车鼓重量，m表示所述被测车辆的总重，V_1j′表示所述被测车辆在紧急制动阶段前的速度，V_2j′表示所述被测车辆在紧急制动阶段后的速度，j为正整数。Wherein, T _ej represents the second heat value generated by the brake drum during the emergency braking phase of the vehicle under test within the jth preset distance interval, n represents the number of axles of the vehicle under test, and C represents the vehicle under test The specific heat capacity of the brake drum, m' represents the weight of the brake drum of the tested vehicle, m represents the total weight of the tested vehicle, V _1j ' represents the speed of the tested vehicle before the emergency braking stage, V _2j ' Indicates the speed of the vehicle under test after the emergency braking stage, and j is a positive integer. 6.根据权利要求1所述的安全车速预测方法，其特征在于，通过以下公式计算所述第二刹车鼓温度：6. The safe vehicle speed prediction method according to claim 1, wherein the temperature of the second brake drum is calculated by the following formula: T_j＝T_cj+N_j×T_ej+T_j-1，T _j =T _cj +N _j ×T _ej +T _j-1 , 其中，T_j表示所述被测车辆行驶完第j个预设距离间隔后刹车鼓的第二温度，T_ej表示所述被测车辆在第j个预设距离间隔内紧急制动阶段刹车鼓产生的第二热量值，T_cj表示所述被测车辆在第j个预设距离间隔内控速行驶阶段所述刹车鼓产生的第一热量值，T_j-1表示所述被测车辆刚进入第j个预设距离间隔后刹车鼓的初始温度阈值，N_j代表所述被测车辆在第j个预设距离间隔的紧急制动次数，j为正整数。Among them, T _j represents the second temperature of the brake drum after the vehicle under test has traveled the jth preset distance interval, and T _ej represents the brake drum of the vehicle under test during the emergency braking stage within the jth preset distance interval The second calorific value generated, T _cj represents the first calorific value generated by the brake drum during the speed-controlled driving phase of the vehicle under test within the jth preset distance interval, and T _j-1 represents the vehicle under test just entered The initial temperature threshold of the brake drum after the jth preset distance interval, _Nj represents the number of emergency braking times of the tested vehicle at the jth preset distance interval, and j is a positive integer. 7.一种车载终端，其特征在于，包括：7. A vehicle-mounted terminal, comprising: 存储器和处理器，所述存储器和所述处理器之间互相通信连接，所述存储器中存储有计算机指令，所述处理器通过执行所述计算机指令，从而执行权利要求1-6中任一项所述的安全车速预测方法。A memory and a processor, wherein the memory and the processor are connected in communication with each other, the memory stores computer instructions, and the processor executes any one of claims 1-6 by executing the computer instructions The described safe vehicle speed prediction method. 8.一种安全车速预测系统，其特征在于，包括：路侧模块，车载模块以及如权利要求7所述的车载终端；8. A safe vehicle speed prediction system, comprising: a roadside module, a vehicle-mounted module and the vehicle-mounted terminal as claimed in claim 7; 所述路侧模块包括路侧信息采集模块、路侧定位模块和第一无线通信模块，所述车载模块包括车载采集模块、车载定位模块以及第二无线通信模块；The roadside module includes a roadside information collection module, a roadside positioning module and a first wireless communication module, and the vehicle-mounted module includes a vehicle-mounted collection module, a vehicle-mounted positioning module and a second wireless communication module; 所述路侧信息采集模块用于采集所述连续下坡路段的几何参数和环境参数，所述路侧定位模块用于采集所述连续下坡路段的坐标信息；The roadside information collection module is used to collect geometric parameters and environmental parameters of the continuous downhill road section, and the roadside positioning module is used to collect the coordinate information of the continuous downhill road section; 所述第一无线通信模块分别与所述路侧信息采集模块、路侧定位模块和第二通信模块连接，所述路侧模块通过第一无线通信模块将所述几何参数、环境参数和坐标信息传输给所述车载模块；The first wireless communication module is respectively connected with the roadside information collection module, the roadside positioning module and the second communication module, and the roadside module transmits the geometric parameters, environmental parameters and coordinate information through the first wireless communication module. transmitted to the on-board module; 所述车载采集模块用于采集所述被测车辆的特征参数、紧急制动次数和初始刹车鼓温度，所述车载定位模块用于采集所述被测车辆的坐标位置；The vehicle-mounted acquisition module is used to collect characteristic parameters, the number of emergency braking times and the initial brake drum temperature of the vehicle under test, and the vehicle-mounted positioning module is used to collect the coordinate position of the vehicle under test; 所述车载终端与所述车载模块连接，用于根据所述几何参数、环境参数、坐标信息、初始刹车鼓温度、坐标位置、特征参数和紧急制动次数计算所述被测车辆的建议速度。The in-vehicle terminal is connected to the in-vehicle module, and is used for calculating the recommended speed of the vehicle under test according to the geometric parameters, environmental parameters, coordinate information, initial brake drum temperature, coordinate position, characteristic parameters and the number of emergency braking times.