A vehicle speed guidance and control method for the traffic safety protection area during the reconstruction and expansion of expressways based on gradient deceleration

Abstract

The present invention discloses a vehicle speed guidance control method for the traffic safety area during the reconstruction and expansion of expressways based on gradient speed reduction, which relates to the field of intelligent traffic safety technology. The method includes obtaining the road traffic safety plan for the reconstructed and expanded traffic safety section, setting detectors and intelligent roadside units (RSUs), and connecting the vehicle information of passing vehicles to the high-speed server base station in real time. The speed preset value and section length of gradient speed reduction are determined according to the vehicle running speed, the rear-end collision threshold of the following vehicle, and the braking distance. Voice broadcast and vehicle speed guidance are provided to drivers with in-vehicle devices, and mobile device communication prompts are given to drivers without in-vehicle devices. This vehicle speed guidance method can effectively avoid traffic accidents caused by temporary braking behaviors at the ramp exits of the traffic safety section by guiding drivers to reduce speed through multi-level gradients, and ensure the safe passage of the reconstructed and expanded section.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent traffic safety, and particularly to a vehicle speed guidance control method for the traffic safety area during the reconstruction and expansion of expressways based on gradient speed reduction. Background Art

[0002] During the reconstruction and expansion construction of expressways, in order to ensure the normal passage of expressways and meet traffic demands, traffic organization generally adopts the traffic safety measure of "constructing while keeping the road open". That is, when one half of the road is closed for construction, the original road or the newly built half of the road is fully utilized to ensure normal passage.

[0003] However, during the reconstruction and expansion construction, temporary openings are often made in the central isolation belt or trumpet-shaped ramps are used to meet the needs of vehicle entry and exit. As a result, the road alignment and exit positions change significantly. The temporary road alignment changes and the settings of entrances and exits lead to serious cognitive errors of drivers in the traffic safety section, and cannot timely stimulate drivers to make corresponding driving behavior responses. Therefore, drivers often take some inappropriate driving measures or driving judgments in the traffic safety section due to the change of the driving environment, such as emergency braking, emergency lane change, missing the ramp exit, etc., which have a serious adverse impact on the safe operation of the traffic flow in the traffic safety section. At this time, if certain vehicle speed guidance measures can be taken for the drivers who need to drive into and out of the ramp in the section where the traffic safety changes, such as temporary ramp entrances and exits, this kind of phenomenon will be improved.

[0004] However, due to the differences in the construction and policies of expressway reconstruction and expansion projects across the country, there is no unified safety guidance measure for the traffic safety section. Generally, traditional traffic signs or guardrail enclosures are used for guidance, and the guiding effect on drivers is quite limited, and the traffic safety of the traffic safety section is difficult to guarantee. Summary of the Invention

[0005] To solve the above problems, the present application provides a vehicle speed guidance control method for the traffic safety area during the reconstruction and expansion of expressways based on gradient speed reduction, which conducts hierarchical vehicle speed guidance for the drivers of vehicles that need to drive out of the ramp in the traffic safety section, and transmits gradient speed reduction information and road information to the drivers to guide the vehicles to pass through the expressway exit or other key sections safely and efficiently. To solve the problem that the weak safety guidance in the traffic safety section during the expressway reconstruction and expansion project may exacerbate the traffic safety and congestion of the section.

[0006] A further purpose is that the established vehicle speed guidance control method for the traffic safety area during the reconstruction and expansion of expressways based on gradient speed reduction can give drivers speed reminders and safety guidance layer by layer and step by step with the help of roadside equipment, avoiding the single and fixed visual reminder of traditional traffic signs, intervening in the driving behavior of drivers from multiple angles, and guiding the vehicles to pass through the traffic safety section safely and smoothly.

[0007] In this application, a vehicle speed guidance control method for the traffic safety protection area during the reconstruction and expansion of expressways based on gradient deceleration is provided, including the following steps:

[0008] S1. Obtain the road alignment, traffic safety protection plan, and the positions of temporary ramp entrances and exits of the reconstruction and expansion traffic safety protection section, determine the gradient deceleration range upstream of the exit ramp, and set detectors and intelligent roadside devices before the gradient deceleration range upstream of the exit ramp RSU , and obtain vehicle information in real time. The vehicle information includes vehicle basic information and vehicle running speed;

[0009] S2. Obtain the real-time parameters of the detector, obtain the vehicle running speed information according to the real-time parameters, and combine the first-level gradient deceleration TTC threshold constraint to calculate the first-level gradient deceleration speed limit value, and calculate the second-level gradient deceleration speed limit value and the third-level gradient deceleration speed limit value according to the deceleration decreasing law combined with the first-level gradient deceleration speed limit value. The deceleration decreasing law is decrease hierarchically;

[0010] S3. Divide the section into a preliminary deceleration area, a lane-changing area, and a stable deceleration area according to the first-level gradient deceleration speed limit value, the second-level gradient deceleration speed limit value, and the third-level gradient deceleration speed limit value, and determine the length of the lane-changing area and the length of the stable deceleration area in combination with the driver's reaction time and the braking distance of the driving vehicle to obtain the road alignment;

[0011] S4. Dynamically display the first-level gradient speed limit value, the second-level gradient speed limit value, and the traffic safety protection section road alignment on the road infrastructure to obtain a deceleration strategy. The road infrastructure includes a dynamic gradient deceleration indication sign system and a speed limit capture device, and the road infrastructure is communicatively connected to in-vehicle devices;

[0012] S5. Use the traffic safety protection section road alignment as the input end of the in-vehicle device, and inform the driver of the traffic safety protection section road alignment and gradient deceleration information through the in-vehicle device and conduct voice broadcast;

[0013] S6. Define vehicles without in-vehicle device navigation as non-communicating vehicles. Obtain the communication information of the vehicle and the driver when the non-communicating vehicle enters the highway toll station. When the non-communicating vehicle enters the traffic safety protection section with gradient deceleration, according to the deceleration strategy, the high-speed base station server sends a gradient deceleration prompt sound, a text message pop-up notification, and a vibration to the driver and guides the driver to pass through the successive gradient deceleration sections according to the prompt of the vehicle speed guidance device.

[0014] Preferably, the traffic safety protection plan in S1 includes at least: one-way traffic in the inner lane with the outer lane closed, and one-way traffic in the borrowed oncoming inner lane with the lane closed.

[0015] Preferably, in S2 TTCThe threshold refers to the safe estimated time before two vehicles collide at the current relative speed and distance;

[0016] Calculate TTC The expression for is:

[0017]

[0018] Where, is the distance between the two vehicles, is the speed of the leading vehicle, is the speed of the trailing vehicle, and the speed of the trailing vehicle is greater than that of the leading vehicle.

[0019] Preferably, in S3, the speed reduction distance in the law of decreasing speed reduction is greater than or equal to ; ;

[0020] The first-level gradient speed reduction speed limit value, the second-level gradient speed reduction speed limit value, and the third-level gradient speed reduction speed limit value are based on the average value of the vehicle speed data detected by the RSU and the threshold of avoiding the risk of the trailing vehicle rear-ending during the deceleration of the leading vehicle;

[0021] Calculate the gradient speed reduction speed limit value The expression for is:

[0022]

[0023] Where, is the speed limit value of the i-level gradient speed reduction, is the distance traveled by the leading vehicle during deceleration, is the deceleration duration, is The threshold, generally taken as 3s, is the comfortable deceleration, and the value is .

[0024] Preferably, in S3, the interval length of the lane change area and the interval length of the stable deceleration area The expressions for are:

[0025]

[0026] Where, is the reaction time of the driver's braking, taking , is the time to maintain a stable speed or change lanes after deceleration, taking , is the road longitudinal slope, positive for uphill and negative for downhill, is the road longitudinal friction factor, and the value range is 0.29~0.44, is the gravitational acceleration, and the value is , the three support frames for three - stage gradient speed reduction are respectively located upstream of the ramp exit , , .

[0027] Preferably, in S4, the dynamic gradient speed - reduction indication sign system is equipped with LED a screen and is set on the gradient speed - reduction support frame. The ramp - exit indication signs, speed - limit capture devices, and dynamic gradient speed - reduction indication signs based on LED are respectively fixed on the gradient speed - reduction support frame.

[0028] Preferably, in S5, the voice broadcast is the voice - prompt statement and direction - guiding statement uploaded to the in - vehicle device server after obtaining the road alignment of the traffic - maintaining section, and the driver is guided through the traffic - maintaining section by voice.

[0029] Preferably, in S6, the communication information is uploaded to the highway server after being obtained.

[0030] Preferably, the vehicle - speed guiding device in S6 includes a dynamic gradient speed - reduction indication sign system based on LED , a speed - limit capture device, a traditional ramp - exit sign, and a guard - rail guiding measure.

[0031] In summary, for a vehicle - speed guiding and control method in a traffic - maintaining area during highway reconstruction and expansion based on gradient speed reduction of the present invention, compared with the traditional vehicle - speed guiding and control technology, this method transmits information about the ramp exit ahead of the traffic - maintaining section and the internal gradient speed - reduction data of the section to the driver through various methods such as communication between in - vehicle devices and mobile devices. It can effectively slow down the speed of vehicles, enabling the driver to better control the vehicle, reducing the possibility of accidents caused by driving too fast into the ramp, and can better guide the vehicle into the ramp step by step, avoiding the situation where the vehicle needs to brake suddenly or change lanes frequently after driving too fast into the ramp. Thus, it improves the overall traffic fluency, enhances the comfort and sense of security of driving, and can help regulate the traffic flow smoothly.

[0032] Next, through the drawings and embodiments, the technical solutions of the present invention will be further described in detail. Brief Description of the Drawings

[0033] Figure 1 is a step - schematic diagram of a vehicle - speed guiding and control method in a traffic - maintaining area during highway reconstruction and expansion based on gradient speed reduction of the present invention;

[0034] Figure 2 is a layout - schematic diagram of each module of the system of a vehicle - speed guiding and control method in a traffic - maintaining area during highway reconstruction and expansion based on gradient speed reduction of the present invention;

[0035] Figure 3This is a schematic structural diagram of the gradient deceleration guiding device support part of a vehicle speed guiding and control method for the traffic safety protection area during the reconstruction and expansion of expressways based on gradient deceleration according to the present invention.

[0036] Reference numerals

[0037] 1, Ramp exit indication sign; 2, Speed limit capture device; 3, Dynamic gradient deceleration indication sign based on LED ; 4, Construction section; 5, Lane change area; 6, Stable deceleration area; 7, Initial deceleration area; 8, Detector; 9, Intelligent roadside device RSU . Detailed implementation manners

[0038] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present application.

[0039] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way serves as a limitation to the present application, its application, or its use.

[0040] Well-known technologies, methods, and devices in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification.

[0041] In all examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

[0042] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains.

[0043] As Figure 1 , Figure 2 and Figure 3 shown, the present invention provides a vehicle speed guiding and control method for the traffic safety protection area during the reconstruction and expansion of expressways based on gradient deceleration. Specifically, as follows, S1. Obtain the road alignment, road traffic safety protection plan, and the positions of temporary ramp entrances and exits of the reconstruction and expansion traffic safety protection section. As Figure 2 shown, determine the upstream gradient deceleration range of the exit ramp, and set a detector and an intelligent roadside device before the upstream gradient deceleration range of the exit ramp RSU to obtain vehicle information in real time and transmit the obtained vehicle information to the expressway server. The vehicle information includes vehicle basic information and vehicle running speed;

[0044] Furthermore, the road traffic maintenance plan for S1 at least includes closing the outer lane of one side for the inner lane to pass, and closing one side of the lane for passing on the opposite inner lane.

[0045] S2. Obtain the real-time parameters of the detector, obtain the vehicle running speed information according to the real-time parameters, and calculate the speed limit value of the first-level gradient deceleration in combination with the first-level gradient deceleration TTC threshold constraint. Calculate the speed limit value of the second-level gradient deceleration and the speed limit value of the third-level gradient deceleration according to the deceleration decreasing rule in combination with the speed limit value of the first-level gradient deceleration, and ensure the smoothness of the gradient deceleration. The deceleration decreasing rule is Decrease Hierarchically, ensure that the speed reaching the ramp exit after the last layer of decrease does not exceed the ramp speed limit . Table 1 shows the specific speed limit values of this implementation example.

[0046] Table 1

[0047]

[0048] Furthermore, in S2 TTC The threshold refers to the safe predicted time before two vehicles collide at the current relative speed and distance;

[0049] The expression for calculating TTC is:

[0050]

[0051] Among them, is the distance between two vehicles, is the speed of the leading vehicle, is the speed of the following vehicle, and the speed of the following vehicle is greater than the speed of the leading vehicle.

[0052] S3. Divide the road section into a preliminary deceleration area, a lane-changing area, and a stable deceleration area according to the speed limit value of the first-level gradient deceleration, the speed limit value of the second-level gradient deceleration, and the speed limit value of the third-level gradient deceleration, and determine the length of the lane-changing area and the length of the stable deceleration area in combination with the driver's reaction time and the braking distance of the driving vehicle to obtain the road alignment;

[0053] Furthermore, in the deceleration decreasing rule in S3, the decreased speed distance is greater than or equal to ;

[0054] The speed limit value of the first-level gradient deceleration, the speed limit value of the second-level gradient deceleration, and the speed limit value of the third-level gradient deceleration are based on RSU The average value of the detected vehicle speed data and the risk of avoiding rear-end collision of the following vehicle during the deceleration of the leading vehicle as the threshold;

[0055] Calculate the expression for the speed limit value of the gradient deceleration is:

[0056]

[0057] Among them, is the speed limit value of the i-level gradient speed reduction, is the distance that the vehicle in front decelerates and travels, is the deceleration duration, is the threshold value, generally taken as 3s, is the comfortable deceleration, and the value is .

[0058] In this embodiment, it is assumed that the average speed of the passing vehicle is , and the initial distance between the front and rear vehicles is .

[0059] Furthermore, the interval length of the lane change area and the interval length of the stable deceleration area in S3 are expressed as:

[0060]

[0061] Among them, is the reaction time of the driver to apply the braking brake, taken as 2.5s, is the time to maintain a stable speed or change lanes after deceleration, taken as 5s, is the road longitudinal slope, positive for uphill and negative for downhill, is the road longitudinal friction factor, and the value range is 0.29~0.44, is the gravitational acceleration, and the value is , and the three support frames of the three-level gradient speed reduction are respectively located upstream of the ramp exit , , . In the middle section of the gradient speed reduction, it is necessary to ensure that the driver has enough driving distance in this interval to decelerate. Otherwise, too much braking force is not conducive to driving safety. In this embodiment, takes the value of 0.4, and and are substituted into the above formula. Table 2 shows the lengths of the lane change area and the stable deceleration area in this embodiment.

[0062] Table 2

[0063]

[0064] S4. Display the first-level gradient speed limit value, the second-level gradient speed limit value, and the alignment of the traffic maintenance section dynamically on the road infrastructure to obtain a speed reduction strategy. The road infrastructure includes a dynamic gradient speed reduction indication sign system and a speed limit capture device, and the road infrastructure is communicatively connected to the in-vehicle device;

[0065] Further, the dynamic gradient speed reduction indication sign system in S4 is equipped with LED a screen and is set on the gradient speed reduction support frame. On the gradient speed reduction support frame, a ramp exit indication sign, a speed limit capture device, and a dynamic gradient speed reduction indication sign based on LED are respectively fixed. The structure schematic diagram of the support frame is as shown in Figure 3 . The dynamic gradient speed reduction indication sign based on LED includes "The gradient speed limit value of the road ahead is , and the speed limit length is ", "The gradient speed limit value of the road ahead is , and the speed limit length is ", and "The gradient speed limit value of the road ahead is , and the distance from the ramp is ".

[0066] S5. For a driving vehicle that relies on in-vehicle devices including an in-vehicle display screen (such as a center console screen or an instrument panel display screen) for navigation, the in-vehicle device is communicatively connected to the road infrastructure, and the obtained road alignment data of the traffic maintenance section is used as the input end of the in-vehicle device. The in-vehicle device notifies the driver of the road alignment and gradient speed reduction information of the traffic maintenance section and conducts voice announcements;

[0067] Further, the voice announcements in S5 are voice prompt statements and direction guidance statements uploaded to the in-vehicle device server after obtaining the road alignment of the traffic maintenance section, and the driver is guided through the traffic maintenance section safely by means of voice to drive out of the traffic maintenance section safely. The voice prompts include:

[0068] "The road ahead is a gradient speed reduction section for highway reconstruction and expansion. Please reduce the speed for the first time to enter the traffic maintenance section and do not change lanes";

[0069] "The road ahead is a gradient speed reduction section for highway reconstruction and expansion. Please reduce the speed for the second time to change lanes and pay attention to the vehicles coming from behind";

[0070] "The road ahead is a gradient speed reduction section for highway reconstruction and expansion. Please reduce the speed for the third time to prepare to drive out of the reconstruction and expansion section and pay attention to the ramp exit".

[0071] S6. Define vehicles without in-vehicle devices as non-communicating vehicles. The intelligent roadside device RSU will upload the detected vehicle information to the highway base station server if it is a non-communicating vehicle. When a non-communicating vehicle enters the highway toll station, the communication information of the vehicle and the driver is obtained. When a non-communicating vehicle enters the traffic maintenance section with gradient speed reduction, the highway base station server sends a gradient speed reduction prompt sound, a text message pop-up notification, and a vibration to the driver according to the speed reduction strategy and guides the driver to pass through the gradient speed reduction sections step by step according to the prompts of the vehicle speed guidance device and drive out of the traffic maintenance section safely.

[0072] Further, the communication information in S6 is uploaded to a high-speed server after being obtained.

[0073] Further, the vehicle speed guiding device in S6 includes LED a dynamic gradient deceleration indication sign system, a speed limit capture device, a traditional ramp exit sign, and a guardrail guiding measure based on

[0074] By sending the alignment data and gradient deceleration information of the traffic maintenance section through in-vehicle devices and mobile communication devices, and through prompts such as display screens, voice broadcasts, and pop-up messages, the driving speed is reasonably adjusted under the guidance of three-level gradient deceleration, facilitating the driver to decelerate and change lanes in advance, ensuring that the driver can safely and smoothly drive out of the traffic maintenance section, effectively avoiding traffic flow mutations caused by the driver suddenly reacting to change lanes and braking urgently when approaching the ramp exit, affecting the traffic efficiency and smoothness of the traffic maintenance section, and causing instability or even accidents in the traffic flow.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A vehicle speed guidance control method for a highway reconstruction and expansion maintenance zone based on gradient speed reduction, characterized in that: The following steps are involved: S1. Obtain the road alignment, road maintenance plan and temporary ramp entrance and exit locations of the reconstruction and expansion section, determine the gradient speed reduction range upstream of the exit ramp, and set up detectors and intelligent roadside equipment in front of the gradient speed reduction range upstream of the exit ramp RSU , real-time acquisition of vehicle information, the vehicle information including basic vehicle information and vehicle running speed; S2. Obtain the real-time parameters of the detector, obtain the vehicle running speed information based on the real-time parameters, and combine the first-level gradient deceleration TTC The threshold constraint calculates the first-level gradient speed reduction limit value, and the second-level gradient speed reduction limit value and the third-level gradient speed reduction limit value are calculated according to the speed reduction decreasing law combined with the first-level gradient speed reduction limit value. The speed reduction decreasing law is: reduce Descending levels; S3, dividing the road section into a preliminary speed reduction zone, a lane change zone and a stable speed reduction zone according to the first-level gradient speed reduction speed limit value, the second-level gradient speed reduction speed limit value and the third-level gradient speed reduction speed limit value, and determining the length of the lane change zone and the length of the stable speed reduction zone in combination with the driver's reaction time and the braking distance of the driving vehicle to obtain the road section line shape; S4, dynamically displaying the first-level gradient speed limit value, the second-level gradient speed limit value and the road section line shape on the road infrastructure to obtain a speed reduction strategy, wherein the road infrastructure includes a dynamic gradient speed reduction indication sign system and a speed limit capture device, and the road infrastructure is communicatively connected with the vehicle-mounted device; S5, using the road alignment of the road section to be maintained as an input terminal of the vehicle-mounted device, and informing the driver of the road alignment and gradient speed reduction information of the road section to be maintained through the vehicle-mounted device and performing voice broadcasting; S6. A vehicle not equipped with an onboard navigation device is defined as a non-communication vehicle. When the non-communication vehicle enters a highway toll station, the communication information between the vehicle and the driver is obtained. When the non-communication vehicle enters a gradient speed reduction section, the highway base station server sends a gradient speed reduction prompt sound, SMS pop-up notification, and vibration to the driver according to the speed reduction strategy, and guides the driver to pass through the gradient speed reduction section step by step according to the prompt of the vehicle speed guidance device; S2 TTC The threshold refers to the safe estimated time before the two vehicles collide at the current relative speed and distance; calculate TTC The expression is: ； in, is the distance between the two vehicles, is the speed of the vehicle ahead, is the speed of the rear vehicle, which is greater than the speed of the front vehicle; S3 speed reduction law is reduced The speed distance is greater than or equal to ; The first-level gradient speed reduction limit value, the second-level gradient speed reduction limit value and the third-level gradient speed reduction limit value are based on RSU The average value of the detected vehicle speed data and the risk of rear-end collision with the rear vehicle during the deceleration of the front vehicle are used as the threshold value; Calculate the speed limit of the gradient reduction The expression is: ； in, is the speed limit value of the i-level gradient reduction, is the distance the front vehicle decelerates, is the deceleration duration, for The threshold is taken as , is the comfortable deceleration, and its value is ; The length of the lane change area in S3 , the length of the stable deceleration zone The expression is: ； in, is the driver's braking reaction time. , The time to maintain a stable speed or change lanes after deceleration is 5s. is the longitudinal slope of the road, positive for uphill and negative for downhill. The longitudinal friction factor of the road ranges from 0.29 to 0.

44. is the acceleration due to gravity, which is 9.8 m / s 2 The three support frames for the three-level gradient speed reduction are located upstream of the ramp exit. , , Place.

2. The vehicle speed guidance control method for a highway reconstruction and expansion maintenance zone based on gradient speed reduction according to claim 1 is characterized in that: The road maintenance plan for S1 includes at least half-closed outer lane - use of inner lane, and half-closed lane - use of opposite inner lane for passage.

3. The vehicle speed guidance control method for a highway reconstruction and expansion maintenance zone based on gradient speed reduction according to claim 1 is characterized in that: The dynamic gradient speed reduction indicator system in S4 is equipped with led The screen is arranged on a gradient deceleration support frame, on which a ramp exit sign, a speed limit capture device and a speed limit capture device based on the ramp exit sign are fixed. led Dynamic gradient speed reduction indicator.

4. The vehicle speed guidance control method for a highway reconstruction and expansion maintenance zone based on gradient speed reduction according to claim 1 is characterized in that: The voice broadcast in S5 is the voice prompt and direction guidance statements uploaded to the vehicle-mounted device server after obtaining the road line shape of the guaranteed passage section, and guides the driver through the guaranteed passage section with the help of voice.

5. The vehicle speed guidance control method for a highway reconstruction and expansion maintenance zone based on gradient speed reduction according to claim 1 is characterized in that: The communication information in S6 is uploaded to the high-speed server after being obtained.

6. The vehicle speed guidance control method for a highway reconstruction and expansion maintenance zone based on gradient speed reduction according to claim 1 is characterized in that: The vehicle speed guidance device in S6 includes led Dynamic gradient speed reduction sign system, speed limit capture equipment, traditional ramp exit signs and guardrail guidance measures.

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