CN111681431A - Ramp control system and method based on large-area microwave radar - Google Patents

Abstract

The invention discloses a ramp control system and a method based on a large-area microwave radar, wherein the ramp control system comprises: a traffic signal detection sensor for: acquiring traffic information; a ramp control box for: setting parameters of the traffic signal detection sensor; acquiring traffic information of the traffic signal detection sensor, processing the information, and outputting control scheme selection information; the intelligent annunciator is used for: storing the signal lamp control scheme; acquiring control scheme selection information of the ramp control box to control a signal lamp; the traffic signal detection sensor is in communication connection with the ramp control box, and the ramp control box is in communication connection with the intelligent annunciator. And the on-off of traffic signal lamps is controlled in a self-adaptive manner according to the comprehensive parameters of the average speed Vm of the main road, the average density Fad of the regional vehicles and the ramp overflow Ro, so that the traffic jam condition of the ramp is intelligently controlled, the traffic jam is greatly reduced, and the accident probability is reduced.

Description

Ramp control system and method based on large-area microwave radar

Technical Field

The invention relates to a ramp control system and method based on a large-area microwave radar, and belongs to the technical field of intelligent traffic design.

Background

The urban main road refers to a road which is positioned in a city and is suitable for rapid passing of motor vehicles. According to the design standard of urban expressway, it should provide fast, efficient, comfortable and safe running environment for vehicles. However, with the rapid development of economy, the number of motor vehicles is rapidly increased, and due to the attraction of expressways to travelers, a large amount of traffic flow rushes into the expressways, so that the traffic demand of the expressways exceeds the traffic supply, and the traffic jam phenomenon is frequent, thereby causing the problems of reduced traveling speed, increased traffic accidents, increased fuel consumption, intensified air pollution, reduced operating efficiency and the like.

Because the urban main road is an important component of the whole urban traffic large system, the structural characteristics of the urban main road determine that the traffic condition of the urban main road is influenced by the traffic conditions of the entrance and exit ramps and the ground roads associated with the entrance and exit ramps, and the urban main road is mainly embodied in the following aspects: the overflow phenomenon caused by the overlong queuing at the entrance ramp influences the normal traffic of the ground road. Therefore, it is necessary to combine the ramp control problem with the traffic control problem of the ordinary road to realize the comprehensive control of the main road and the ground road.

The basic principle of the entrance ramp control is that the traffic volume entering the main road is adjusted, so that the traffic demand of the main road does not exceed the capacity of the main road, and the main road is ensured to operate near the optimal state according to a certain performance index. In this way, vehicles that desire to enter the main road are expected to wait in line at the on-ramp before being allowed to enter the main road, and if they do not want to wait on the on-ramp, other alternative routes may be selected to effect traffic diversion. The entrance ramp control can be divided into two categories, timing control and induction control, according to whether the entrance ramp control responds to real-time traffic conditions. The timing control method adopts fixed timing to control the entrance ramp, calculates the fixed ramp regulation rate according to historical traffic data, and has stable timing control operation, but the timing control method cannot adapt to the traffic flow changing in real time and has poor operation effect. The inductive control can detect traffic flow data in real time, but a large amount of traffic flow on the entrance ramp enters the main road easily to cause traffic jam of the main road, so the inductive control is suitable for being used when the traffic flow on the main road is small. Besides timing control and induction control, other traffic control methods for the entrance ramp exist, but all the methods have own applicable conditions, and the traffic control requirements for the entrance ramp are difficult to meet.

Disclosure of Invention

The invention aims to overcome the technical defects in the prior art, solve the technical problems and provide a ramp control system and method based on a large-area microwave radar, which can judge the road congestion condition according to the average speed Vm of a main road, the average density Fad of regional vehicles and the ramp overflow Ro and then adaptively control the turn-on and turn-off of traffic lights so as to reduce the traffic congestion.

The invention specifically adopts the following technical scheme: a ramp control system based on a large-area microwave radar comprises: a traffic signal detection sensor for: acquiring traffic information;

a ramp control box for: setting parameters of the traffic signal detection sensor; acquiring traffic information of the traffic signal detection sensor, processing the information, and outputting control scheme selection information;

the intelligent annunciator is used for: storing the signal lamp control scheme; acquiring control scheme selection information of the ramp control box to control a signal lamp;

the traffic signal detection sensor is in communication connection with the ramp control box, and the ramp control box is in communication connection with the intelligent annunciator.

As a preferred embodiment, the traffic signal detection sensor includes:

the first microwave radar is arranged on the main road and used for measuring the traffic information of the main road;

the second microwave radar is arranged on the signal lamp cross rod and used for measuring ramp traffic information;

and the third microwave radar is arranged on a portal frame or a road side near the entrance of the ramp and is used for detecting the required flow and overflow information of the ramp.

As a preferred embodiment, the traffic information includes: the traffic flow Fc and the average speed Vc of a unit time section; and at the end time of the unit time, detecting the total number Fa of the vehicles in the area and the average vehicle speed Va.

As a preferred embodiment, the parameter setting includes: setting and synchronizing a radar clock; the radar number and the channel number are matched, wherein the 1# channel corresponds to the upstream of a main road, the 2# channel corresponds to the exit of a ramp, the 3# channel corresponds to the entrance of the ramp, and the 4# channel corresponds to the downstream of the main road; and radar parameter setting specifically comprises detection section position, detection area, reporting period, lane number and time.

As a preferred embodiment, the acquiring, by the ramp control box, the traffic information of the traffic signal detection sensor for information processing specifically includes:

acquiring the average speed Vm, specifically including: and the arithmetic average value of the average speed of all the sections and the average speed of the detection area in the control period is as follows: vm is (Σ Vc + Σ Va)/N; when the traffic flow per unit time section Fc is 0, and the total number Fa of the vehicles in the detection area is 0 at the end time of the unit time, the corresponding average speed Vc of the vehicles in the unit time section and the average speed Va of the vehicles in the detection area are not counted into the sum at the end time of the unit time;

acquiring a cross-sectional flow rate Fct, namely the total cross-sectional flow in a control period, namely: fct ═ Σ Fc;

acquiring the average vehicle density Fad of the detection area, specifically comprising: fad ═ Σ Fc/N/lane number/lane length; wherein N represents the number of Fc in a control period; when Fad is equal to 0, Vm is equal to 80km/h, and the image is unblocked;

detecting ramp overflow Ro, which specifically comprises the following steps: ro-1 represents ramp overflow, and default Ro-0; when the ramp Vm is less than or equal to 10km/h and Fad is greater than or equal to 1, judging that the ramp overflows, namely Ro is 1;

and selecting a corresponding control scheme according to the detection data of the traffic signal detection sensor and the control scheme strategy, and sending the control scheme to the intelligent annunciator.

As a preferred embodiment, the control scheme includes an off, evergreen, split-green scheme; the control scheme selection specifically comprises: dividing 4 congestion levels according to the average speed Vm of the main road, the average density Fad of regional vehicles and the ramp overflow Ro, and respectively representing the unblocked main road, the congestion, the severe congestion and the ramp overflow, wherein the method specifically comprises the following steps:

the ramp overflow Ro is 0, the average speed Vm of the main track is more than 60km/h, a closing mode is selected, after 20 evergreen modes continuously appear, the closing mode is selected, when the evergreen requirement appears in the closing mode, the signal lamp still keeps the closing mode, and the signal lamp is not turned on until the requirement of other modes appears;

the ramp overflow Ro is equal to 1, the average speed Vm of the main track is greater than 60km/h, and an evergreen mode is selected;

otherwise, the green ratio scheme is switched to.

As a preferred embodiment, the split scheme selects a fixed control period mode, and specifically includes:

the ramp overflow Ro is equal to 0, 40km/h < the main track average speed Vm is less than or equal to 60km/h, a green-to-signal ratio scheme 1 is selected, and signal lamp green is controlled for 20 s;

the ramp overflow Ro is equal to 0, the average speed Vm of the main track is less than or equal to 40km/h after 25km/h, a green-to-signal ratio scheme 1 is selected, and the green of a signal lamp is controlled for 15 s;

and (3) setting the ramp overflow Ro to be 0, setting the 10km/h < the main track average speed Vm to be less than or equal to 25km/h, selecting a closing mode, adopting a green signal ratio scheme 1, and controlling the signal lamp green for 10 s.

The invention also provides a ramp control method based on the large-area microwave radar, which is characterized by comprising the following steps of:

step SS 1: a traffic signal detection sensor acquires traffic information;

step SS 2: the ramp control box acquires the traffic information of the traffic signal detection sensor to perform information processing and outputs control scheme selection information;

step SS 3: and the intelligent annunciator acquires the control scheme selection information of the ramp control box to control the signal lamp.

As a preferred embodiment, step SS2 specifically includes: acquiring the average speed Vm, specifically including: and the arithmetic average value of the average speed of all the sections and the average speed of the detection area in the control period is as follows: vm is (Σ Vc + Σ Va)/N; when the traffic flow per unit time section Fc is 0, and the total number Fa of the vehicles in the detection area is 0 at the end time of the unit time, the corresponding average speed Vc of the vehicles in the unit time section and the average speed Va of the vehicles in the detection area are not counted into the sum at the end time of the unit time;

acquiring a cross-sectional flow rate Fct, namely the total cross-sectional flow in a control period, namely: fct ═ Σ Fc;

acquiring the average vehicle density Fad of the detection area, specifically comprising: fad ═ Σ Fc/N/lane number/lane length; wherein N represents the number of Fc in a control period; when Fad is equal to 0, Vm is equal to 80km/h, and the image is unblocked;

detecting ramp overflow Ro, which specifically comprises the following steps: ro-1 represents ramp overflow, and default Ro-0; when the ramp Vm is less than or equal to 10km/h and Fad is greater than or equal to 1, judging that the ramp overflows, namely Ro is 1;

and selecting a corresponding control scheme according to the detection data of the traffic signal detection sensor and the control scheme strategy, and sending the control scheme to the intelligent annunciator.

As a preferred embodiment, the signal lamp control scheme includes an off, evergreen, and green signal ratio scheme, and the control scheme specifically includes: dividing 4 congestion levels according to the average speed Vm of the main road, the average density Fad of regional vehicles and the ramp overflow Ro, and respectively representing the unblocked main road, the congestion, the severe congestion and the ramp overflow, wherein the method specifically comprises the following steps:

the ramp overflow Ro is 0, the average speed Vm of the main track is more than 60km/h, a closing mode is selected, after 20 evergreen modes continuously appear, the closing mode is selected, when the evergreen requirement appears in the closing mode, the signal lamp still keeps the closing mode, and the signal lamp is not turned on until the requirement of other modes appears;

the ramp overflow Ro is equal to 1, the average speed Vm of the main track is greater than 60km/h, and an evergreen mode is selected;

otherwise, the split scheme is selected.

The invention achieves the following beneficial effects: aiming at the limitation of application conditions existing in the traditional entrance ramp traffic control method and the technical requirement of the traffic control of the entrance ramp which is difficult to meet, the invention designs a ramp control system and method based on a large-area microwave radar, and the on-off of traffic signal lamps is controlled in a self-adaptive manner according to the comprehensive parameters of the average speed Vm of a main road, the average density Fad of regional vehicles and the overflow Ro of the ramp, so that the traffic jam condition of the intelligent control ramp is realized, the traffic jam is greatly reduced, and the probability of accidents is reduced; the protocol setting between the radar and the ramp control box improves the detection efficiency, and is convenient and flexible.

Drawings

Fig. 1 is a schematic diagram of an application scenario of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example 1: the invention relates to a ramp control system based on a large-area microwave radar, which comprises five parts, namely a first microwave radar, a second microwave radar, a third microwave radar, a ramp control box and an SCATS intelligent annunciator SCATS. The first microwave radar, the second microwave radar and the third microwave radar are used as traffic information detection sensors and are connected into the ramp control box through a network, control scheme selection information generated by the ramp control box is sent to the intelligent annunciator SCATS control signal lamp through the RS485 communication bus, and the control scheme is stored in the intelligent annunciator in a preset mode.

The specific implementation mode is as follows:

s1, the installation position of the microwave radar, and the installation position and the detection area of the microwave radar are shown in figure 1: the invention adopts 3 microwave radars as the traffic information detection sensors. 1) The first microwave radar is arranged on the main line and used for measuring main road traffic information; 2) the second microwave radar is arranged on a signal lamp cross rod and used for measuring traffic information (actual turn entering rate) of a ramp; 3) and the third microwave radar is arranged on a portal frame or a road side near the entrance of the ramp and is used for detecting the required flow and overflow information of the ramp.

S2, radar provides information: 1) the traffic flow Fc and the average speed Vc of a section (the specific position is set according to the actual condition) in unit time (default 5 s); 2) at the end time of unit time, the total number Fa of vehicles in the area (specifically set according to actual conditions) and the average vehicle speed Va; 3) the data is stored locally.

S3, protocol between the radar and the control box: relevant parameters of each radar are set through the control box according to actual conditions, and the main functions of the control box are as follows: 1) setting and synchronizing a radar clock (sending timing instructions at the same time); 2) radar number and channel number match settings (default: upstream of No. 1 main path, 2# ramp outlet, 3# ramp inlet and downstream of No. 4 main path); 3) radar parameter setting: detecting the position of a section, a detection area, a reporting period, the number of lanes, time and the like; 4) radar data display and storage information derivation; 5) outputting a control scheme display; 6) algorithm-related parameters; 7) and displaying real-time traffic flow of each radar.

And S4, processing the information of the ramp control box.

1) Obtaining the average speed Vm (km/h): and controlling the arithmetic mean value of the average speed of all the sections and the average speed of the areas in the period. Namely:

Vm＝(ΣVc+ΣVa)/N；

wherein N represents the total number of the summation average speeds; special attention is paid to: when Fc is 0 and Fa is 0, the corresponding Vc and Va are not summed.

2) The cross-sectional flow rate Fct (total cross-sectional flow over the control period) is obtained: fct ═ Σ Fc (in control period).

3) The regional vehicle average density Fad (number of vehicles/lane/10 m length) is acquired: fad ═ Σ Fc/N/number of lanes/(lane length/10)); n represents the number of Fc in the control period; when Fad is equal to 0, Vm is equal to 80km/h, indicating clear.

5) Ramp overflow ro (ramp overflow) detection: ro ═ 1 denotes ramp overflow (default Ro ═ 0); and when the ramp Vm is less than or equal to 10km/h and Fad is more than or equal to 1, judging that the ramp overflows, namely Ro is 1.

6) Selecting a control scheme: and selecting a corresponding control scheme according to the radar detection data and the control scheme strategy, and sending the control scheme to the annunciator, which is shown in table 1.

And the intelligent annunciator SCATS presets 5 groups of schemes, and selects according to the selection scheme information given by the ramp control box. The specific setting mode is determined by the environmental requirements.

And S5, controlling the scheme.

5.1 Signal light control scheme: the method comprises the following 5 schemes: off, evergreen, split 1, split 2, and split 3. The split-level scheme adopts a fixed-period control mode, and the control period is defaulted to 30s and comprises 3s of yellow flashing (according to the conventional setting). Each scheme is represented by green light time, and the green time is 30s to represent a full-green non-yellow flashing process; in practical application, the number of corresponding split cases is specifically selected according to road conditions and control ideas.

1) Closing: when 20 evergreen schemes appear in succession, the switch is selected to be off. When a normally green demand occurs in the off mode, the off mode is still kept, and the signal lamp is not turned on until other mode demands occur.

2) Evergreen: when the main line is clear or the ramp overflow flag Ro is 1, evergreen is selected, which is specifically shown in table 1.

3) Different split schemes: and selecting according to the main road and ramp traffic flow information measured by the radar, and referring to table 1.

5.2 Signal lamp control scheme selection: and dividing 4 congestion levels according to the average speed Vm of the main road, the average density Fad of regional vehicles and the ramp overflow Ro, and respectively representing the unblocked main road, the congestion, the severe congestion and the ramp overflow. The control scheme selection criteria are shown in table 1.

TABLE 1

Note: 1) the control scheme is mainly based on a main road priority principle;

2) the time in the table is the green time of the control scheme, and the specific numerical value is obtained by analyzing the historical data of the radar b;

the above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (10)

1. A ramp control system based on a large-area microwave radar is characterized by comprising: a traffic signal detection sensor for: acquiring traffic information;

a ramp control box for: setting parameters of the traffic signal detection sensor; acquiring traffic information of the traffic signal detection sensor, processing the information, and outputting control scheme selection information;

the intelligent annunciator is used for: storing the signal lamp control scheme; acquiring control scheme selection information of the ramp control box to control a signal lamp;

the traffic signal detection sensor is in communication connection with the ramp control box, and the ramp control box is in communication connection with the intelligent annunciator.

2. The system of claim 1, wherein the traffic signal detection sensor comprises:

the first microwave radar is arranged on the main road and used for measuring the traffic information of the main road;

the second microwave radar is arranged on the signal lamp cross rod and used for measuring ramp traffic information;

and the third microwave radar is arranged on a portal frame or a road side near the entrance of the ramp and is used for detecting the required flow and overflow information of the ramp.

3. The system according to claim 1, wherein the traffic information includes: the traffic flow Fc and the average speed Vc of a unit time section; and at the end time of the unit time, detecting the total number Fa of the vehicles in the area and the average vehicle speed Va.

4. The system according to claim 1, wherein the parameter setting comprises: setting and synchronizing a radar clock; the radar number and the channel number are matched, wherein the 1# channel corresponds to the upstream of a main road, the 2# channel corresponds to the exit of a ramp, the 3# channel corresponds to the entrance of the ramp, and the 4# channel corresponds to the downstream of the main road; and radar parameter setting specifically comprises detection section position, detection area, reporting period, lane number and time.

5. The ramp control system based on the large-area microwave radar as claimed in claim 1, wherein the step of acquiring the traffic information of the traffic signal detection sensor by the ramp control box and performing information processing specifically comprises:

acquiring the average speed Vm, specifically including: and the arithmetic average value of the average speed of all the sections and the average speed of the detection area in the control period is as follows: vm is (Σ Vc + Σ Va)/N; when the traffic flow per unit time section Fc is 0, and the total number Fa of the vehicles in the detection area is 0 at the end time of the unit time, the corresponding average speed Vc of the vehicles in the unit time section and the average speed Va of the vehicles in the detection area are not counted into the sum at the end time of the unit time;

acquiring a cross-sectional flow rate Fct, namely the total cross-sectional flow in a control period, namely: fct ═ Σ Fc;

acquiring the average vehicle density Fad of the detection area, specifically comprising: fad ═ Σ Fc/N/lane number/lane length; wherein N represents the number of Fc in a control period; when Fad is equal to 0, Vm is equal to 80km/h, and the image is unblocked;

detecting ramp overflow Ro, which specifically comprises the following steps: ro-1 represents ramp overflow, and default Ro-0; when the ramp Vm is less than or equal to 10km/h and Fad is greater than or equal to 1, judging that the ramp overflows, namely Ro is 1;

and selecting a corresponding control scheme according to the detection data of the traffic signal detection sensor and the control scheme strategy, and sending the control scheme to the intelligent annunciator.

6. The system according to claim 5, wherein the control scheme comprises an off, evergreen, split-green scheme; the control scheme selection specifically comprises: dividing 4 congestion levels according to the average speed Vm of the main road, the average density Fad of regional vehicles and the ramp overflow Ro, and respectively representing the unblocked main road, the congestion, the severe congestion and the ramp overflow, wherein the method specifically comprises the following steps:

the ramp overflow Ro is 0, the average speed Vm of the main track is more than 60km/h, a closing mode is selected, after 20 evergreen modes continuously appear, the closing mode is selected, when the evergreen requirement appears in the closing mode, the signal lamp still keeps the closing mode, and the signal lamp is not turned on until the requirement of other modes appears;

the ramp overflow Ro is equal to 1, the average speed Vm of the main track is greater than 60km/h, and an evergreen mode is selected;

otherwise, the green ratio scheme is switched to.

7. The ramp control system based on the large-area microwave radar as claimed in claim 6, wherein the split control scheme adopts a fixed control period mode, and specifically comprises:

the ramp overflow Ro is equal to 0, 40km/h < the main track average speed Vm is less than or equal to 60km/h, a green-to-signal ratio scheme 1 is selected, and signal lamp green is controlled for 20 s;

the ramp overflow Ro is equal to 0, the average speed Vm of the main track is less than or equal to 40km/h after 25km/h, a green-to-signal ratio scheme 1 is selected, and the green of a signal lamp is controlled for 15 s;

and (3) setting the ramp overflow Ro to be 0, setting the 10km/h < the main track average speed Vm to be less than or equal to 25km/h, selecting a closing mode, adopting a green signal ratio scheme 1, and controlling the signal lamp green for 10 s.

8. A ramp control method based on a large-area microwave radar is characterized by comprising the following steps:

step SS 1: a traffic signal detection sensor acquires traffic information;

step SS 2: the ramp control box acquires the traffic information of the traffic signal detection sensor to perform information processing and outputs control scheme selection information;

step SS 3: and the intelligent annunciator acquires the control scheme selection information of the ramp control box to control the signal lamp.

9. The ramp control method based on the large-area microwave radar according to claim 8, wherein step SS2 specifically includes: acquiring the average speed Vm, specifically including: and the arithmetic average value of the average speed of all the sections and the average speed of the detection area in the control period is as follows: vm is (Σ Vc + Σ Va)/N; when the traffic flow per unit time section Fc is 0, and the total number Fa of the vehicles in the detection area is 0 at the end time of the unit time, the corresponding average speed Vc of the vehicles in the unit time section and the average speed Va of the vehicles in the detection area are not counted into the sum at the end time of the unit time;

acquiring a cross-sectional flow rate Fct, namely the total cross-sectional flow in a control period, namely: fct ═ Σ Fc;

acquiring the average vehicle density Fad of the detection area, specifically comprising: fad ═ Σ Fc/N/lane number/lane length; wherein N represents the number of Fc in a control period; when Fad is equal to 0, Vm is equal to 80km/h, and the image is unblocked;

detecting ramp overflow Ro, which specifically comprises the following steps: ro-1 represents ramp overflow, and default Ro-0; when the ramp Vm is less than or equal to 10km/h and Fad is greater than or equal to 1, judging that the ramp overflows, namely Ro is 1;

and selecting a corresponding control scheme according to the detection data of the traffic signal detection sensor and the control scheme strategy, and sending the control scheme to the intelligent annunciator.

10. The ramp control method based on the large-area microwave radar according to claim 9, wherein the signal lamp control scheme comprises an off, evergreen and green signal ratio scheme, and the control scheme selection specifically comprises: dividing 4 congestion levels according to the average speed Vm of the main road, the average density Fad of regional vehicles and the ramp overflow Ro, and respectively representing the unblocked main road, the congestion, the severe congestion and the ramp overflow, wherein the method specifically comprises the following steps:

the ramp overflow Ro is 0, the average speed Vm of the main track is more than 60km/h, a closing mode is selected, after 20 evergreen modes continuously appear, the closing mode is selected, when the evergreen requirement appears in the closing mode, the signal lamp still keeps the closing mode, and the signal lamp is not turned on until the requirement of other modes appears;

the ramp overflow Ro is equal to 1, the average speed Vm of the main track is greater than 60km/h, and an evergreen mode is selected;

otherwise, the split scheme is selected.

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