Cooperative control method for port collection and distribution expressways

Abstract

The invention discloses a port collection and distribution highway cooperative control method, and the method comprises the steps: firstly calculating a bottleneck expected flow through a feedback control mechanism based on the traffic flow information of a current cooperative control period; dividing the bottleneck expected flow into expressway weight flow and entrance ramp weight flow according to the occupation rate weight of the expressway and the entrance ramp, then calculating queue management expected flow, and judging the size relation of the variable speed limit change state, the entrance ramp weight flow and the queue management expected flow. Selecting different strategies to calculate a speed limit value and a confluence duration, updating a preset speed limit value of a variable speed limit control area by adopting the currently calculated speed limit value, and updating a preset confluence duration of an entrance ramp control area by adopting the currently calculated confluence duration, so as to realize the cooperative control of the current cooperative control period; the method has the advantages of being high in response speed, high in control precision and capable of effectively adapting to port collecting and distributing expressways with high flow volatility.

Description

Technical Field

[0001] The invention relates to a control method, and in particular to a coordinated control method for a port collection and distribution highway. Background Art

[0002] With the development of global trade, ports are becoming increasingly important as logistics and transportation hubs. In order to improve the port collection and distribution capabilities, countries around the world have invested heavily in the construction of port collection and distribution network infrastructure. Among them, road transportation has become the most important way of port collection and distribution because of its superiority of "port to door". However, with the increasing throughput of ports, congestion on port collection and distribution highways occurs frequently and has become an important bottleneck restricting the competitiveness of ports. It not only reduces the traffic efficiency and capacity of the road, but also has a serious impact on fuel consumption and environmental pollution. There is an urgent need for a control method to solve the congestion problem on port collection and distribution highways.

[0003] In the study of highway traffic control methods, ramp control and variable speed limit control are the most widely used control methods, but both methods have control constraints. Ramp control is constrained by entrance ramp queue management and minimum convergence flow, and variable speed limit control is constrained by the minimum speed limit value and the maximum change value. When the control reaches the limit, the control effect will decrease, resulting in slow response speed, low control accuracy, and inability to effectively adapt to port collection and distribution highways with strong traffic fluctuations.

[0004] In recent years, a collaborative control method based on ramp control and variable speed limit control has emerged, which can solve the problem of low control accuracy of the above-mentioned single control. Among them, the model-based collaborative control can effectively adapt to the port collection and distribution highway with strong traffic fluctuations by constructing an accurate traffic flow model for control. However, due to the many interference factors of the port collection and distribution highway, the traffic flow model has a large and complex calculation amount and a slow response speed; the rule-based collaborative control method controls by setting rules and conditions, and has a fast response speed, but the established rules have limited ability to control the port collection and distribution highway, and cannot effectively adapt to the port collection and distribution highway with strong traffic fluctuations. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a coordinated control method for a port collection and distribution highway which has fast response speed, high control accuracy and can effectively adapt to port collection and distribution highways with strong flow fluctuations.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: a coordinated control method for port collection and distribution highways, based on the traffic flow information of the current coordinated control cycle, using a feedback control mechanism to first calculate the expected bottleneck flow, and divide the bottleneck expected flow into highway weighted flow and entrance ramp weighted flow according to the occupancy weights of the highway and the entrance ramp, and then calculate the expected queue management flow, and by judging the relationship between the variable speed limit change state, the entrance ramp weighted flow and the queue management expected flow, select different strategies to calculate the speed limit value and the confluence time, use the currently calculated speed limit value to update the speed limit value of the preset variable speed limit control area, and use the currently calculated confluence time to update the preset confluence time of the entrance ramp control area, so as to realize the coordinated control of the current coordinated control cycle, and in this cycle, realize the coordinated control of the port collection and distribution highways.

[0007] Compared with the prior art, the advantage of the present invention is that after the entrance ramp control area and the entrance ramp control area are preset, the speed limit value and the confluence time can be calculated based on the traffic flow information of the current collaborative control period by using the feedback control mechanism, without the need to build a complex prediction model, saving calculation time and calculation resources, fast response speed, ensuring the real-time control, using the feedback control mechanism to calculate the speed limit value and the confluence time, and in each collaborative control period, the currently calculated speed limit value is applied to the variable speed limit control area and the currently obtained confluence time is applied to the entrance ramp control area, so as to realize the real-time update of the speed limit value of the variable speed limit control area And the real-time update of the confluence time in the entrance ramp control area, with high control accuracy. In addition, in the process of calculating the speed limit value and the confluence time, the highway weighted flow and the entrance ramp weighted flow are divided according to the occupancy weights of the highway and the entrance ramp, and the expected flow for queue management is calculated. By judging the relationship between the change state of the variable speed limit, the entrance ramp weighted flow and the expected flow for queue management, different strategies are matched to calculate the speed limit value and the confluence time, so that it can effectively adapt to the port collection and distribution highway with strong traffic volatility. Therefore, the present invention has fast response speed, high control accuracy, and can effectively adapt to the port collection and distribution highway with strong traffic volatility.

[0008] Furthermore, the method for coordinated control of a port collection and distribution highway comprises the following steps:

[0009] Step 1: Divide the port collection and distribution control area into a variable speed limit control area, an acceleration area, a bottleneck area, and an entrance ramp control area. Take the connection point between the entrance ramp and the highway as the starting point, and go against the direction of the highway traffic flow from the starting point l v The starting point of the variable speed limit control area is at meters. v=1600, the speed of vehicles traveling in the variable speed control area is controlled by the speed limit value set in the variable speed control area; the distance from the starting point to the opposite direction of the highway traffic flow is l a The variable speed limit control area ends at 1 meter, which is also the starting point of the acceleration area. a =400, vehicles entering the acceleration zone are allowed to accelerate; along the direction of the highway traffic flow, the distance from the starting point is l b The end point of the acceleration area is at the same time the starting point of the bottleneck area. b =400, along the direction of traffic flow on the highway, the distance from the starting point is l o The bottleneck area is at the end point, l o =800; Distance from the starting point to the opposite direction of the entrance ramp traffic flow l r The starting point of the entrance ramp control area is at meters. r =630, vehicles entering the entrance ramp control area are controlled by ramp traffic lights, and the connection point between the entrance ramp and the highway is also the end point of the entrance ramp control area; a first loop coil detector is installed at the end point of the variable speed limit control area, and the first loop coil detector is used to use electromagnetic sensing technology to obtain the highway detection flow in real time and transmit it to the control system. When each cooperative control cycle is started, the first loop coil detector outputs the highway detection flow of the cooperative control cycle to the control system;

[0010] A second loop coil detector is installed at the starting point of the entrance ramp control area. The second loop coil detector is used to obtain the entrance ramp demand flow in real time by using electromagnetic sensing technology and transmit it to the control system. When each cooperative control cycle is started, the second loop coil detector outputs the entrance ramp demand flow of the cooperative control cycle to the control system;

[0011] A first video vehicle detector is installed at the starting point of the bottleneck area. The first video vehicle detector is used to obtain the bottleneck occupancy rate in real time by using video detection technology and transmit it to the control system. When each cooperative control cycle is started, the first video vehicle detector outputs the bottleneck occupancy rate of the cooperative control cycle to the control system.

[0012] A second video vehicle detector is installed at the starting point of the variable speed limit control area. The second video vehicle detector is used to obtain the variable speed limit control area occupancy rate in real time by using video detection technology and transmit it to the control system. When each cooperative control cycle is started, the second video vehicle detector outputs the variable speed limit control area occupancy rate of the cooperative control cycle to the control system.

[0013] A third video vehicle detector is installed at the starting point of the entrance ramp control area. The third video vehicle detector is used to obtain the entrance ramp control area occupancy rate and the number of entrance ramp queues in real time by using video detection technology and transmit them to the control system. When each cooperative control cycle is started, the third video vehicle detector outputs the entrance ramp control area occupancy rate and the number of entrance ramp queues of the cooperative control cycle to the control system;

[0014] A fourth video vehicle detector is installed at the end of the bottleneck area. The fourth video vehicle detector is used to obtain the total driving time of the port collection and distribution control area in real time by using video detection technology and transmit it to the control system. When each collaborative control cycle is started, the fourth video vehicle detector outputs the total driving time of the port collection and distribution control area of ​​the collaborative control cycle to the control system;

[0015] An air quality detector is installed at the end of the bottleneck area. The air quality detector uses sensors and 32-bit high-precision CPU processing to obtain the total pollutant emissions in the port collection and distribution control area in real time and transmit it to the control system. When each collaborative control cycle is started, the air quality detector outputs the total pollutant emissions in the port collection and distribution control area of ​​the collaborative control cycle to the control system;

[0016] In the control system, each cooperative control cycle is set to T c Seconds, T c =30, after the control starts, the first T c The cycle number of seconds is recorded as 1, and this cycle is called the first cooperative control cycle. c seconds, the number of cycles is increased by 1; the variable speed limit is set to last for n cooperative control cycles, n = 4, if the number of cycles of a certain cooperative control cycle is an integer multiple of n, the variable speed limit change state of the cooperative control cycle is recorded as 1, otherwise, the variable speed limit change state of the cooperative control cycle is recorded as 0; after the kth T c The period of seconds is the kth cooperative control period, k = 1, 2, 3, ...;

[0017] Step 2: When entering the kth coordinated control cycle, the kth coordinated control begins. The specific control process is:

[0018] S2.1: Set the bottleneck expected flow of the k+1th cooperative control cycle to vehicles per hour, determine whether the current value of k is equal to 1. If so, use formula (1) to calculate If not, use formula (2) to calculate

[0019]

[0020] Among them, KP Kilometers per hour is the proportional coefficient, 0≤K P ≤10,K I Kilometers per hour is the integration coefficient, 10≤K I ≤15; Vehicles per kilometer is the bottleneck occupancy rate setting value, q cap vehicles per hour is the highway capacity, q cap =3470;o out (k) The bottleneck occupancy rate of the kth cooperative control cycle per kilometer, obtained by the first video vehicle detector; out (k-1) vehicles per kilometer is the bottleneck occupancy rate of the k-1th cooperative control cycle, obtained by the first video vehicle detector; when k ≥ 2, is the bottleneck expected flow of the kth cooperative control cycle. When k = 1,

[0021] S2.2: Set the freeway weight of the k+1th coordinated control cycle to w1(k+1); the entrance ramp weight to w2(k+1); the freeway weighted flow rate to c(k+1) vehicles per hour; the entrance ramp weighted flow rate to r(k+1) vehicles per hour; use formulas (3)-(6) to calculate w1(k+1), w2(k+1), c(k+1) and r(k+1) respectively:

[0022]

[0023]

[0024] Among them, Λ c is the number of lanes of the port collection and distribution highway, Λ r is the number of lanes on the entrance ramp of the port collection and distribution expressway; μ c is the priority coefficient of the port collection and distribution highway, μ r is the priority coefficient of the entrance ramp of the port collection and distribution expressway, 7≤μ c ≤9, 1≤μ r ≤3; o c (k) The occupancy rate of the variable speed limit control area per kilometer for the kth cooperative control cycle, obtained by the second video vehicle detector; r (k) The occupancy rate of the entrance ramp control area per kilometer for the kth cooperative control cycle, obtained by the third video vehicle detector;

[0025] S2.3: Set the expected flow of queue management in the k+1th cooperative control cycle to vehicles per hour, calculated using formula (7)

[0026]

[0027] in, Vehicle is the set value of the queue quantity, d(k) vehicles per hour is the entrance ramp demand flow in the kth cooperative control cycle, obtained by the second ring coil detector; w(k) vehicles is the number of entrance ramp queues in the kth cooperative control cycle, obtained by the third video vehicle detector;

[0028] S2.4: Set the expected traffic volume of the highway in the k+1th cooperative control cycle to Vehicles per hour; Actual highway traffic volume q c (k+1) vehicles per hour; the actual flow rate of the entrance ramp is q r (k+1) vehicles per hour; the expected speed limit is VSL f (k+1) kilometers per hour; the actual speed limit value is VSL(k+1) kilometers per hour; the confluence time is g(k+1) seconds; determine whether the variable speed limit change state N(k) of the kth cooperative control cycle is equal to 1, if yes, proceed to step S2.5, if not, proceed to step S2.8;

[0029] S2.5: Determine whether r(k+1) is greater than If yes, go directly to step S2.6, if no, go directly to step S2.7;

[0030] S2.6: Calculated using formulas (8)-(13) VSL f (k+1), VSL(k+1), q c (k+1),q r (k+1) and g(k+1), after the calculation is completed, go to step 3;

[0031]

[0032]

[0033] Among them, K R The integration coefficient is per kilometer, K R =0.18;Δ max km / h is the maximum value of the speed limit value set in the variable speed control area, Δ max =20; The saturation flow of the entrance ramp is 1,000 vehicles per hour. When k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period. When k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector;

[0034] S2.7: Calculate q using formulas (14)-(19) r (k+1), g(k+1), VSL f (k+1), VSL(k+1) and q c (k+1), after the calculation is completed, go to step 4;

[0035]

[0036] Among them, K R The integration coefficient is per kilometer, K R =0.18;Δ max km / h is the maximum value of the speed limit value set in the variable speed control area, Δ max =20; The saturation flow of the entrance ramp is 1,000 vehicles per hour. When k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period. When k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector;

[0037] S2.8: First, use formulas (20)-(21) to calculate VSL(k+1) and q c (k+1), and then determine whether r(k+1) is greater than If yes, go directly to step S2.9, if no, go directly to step S2.10;

[0038] VSL(k+1)=VSL(k) (20)

[0039]

[0040] Wherein, when k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period, and when k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector;

[0041] S2.9: Calculate q using formulas (22)-(23) r (k+1) and g(k+1), after the calculation is completed, go to step 3;

[0042]

[0043] in, The saturation flow of the entrance ramp is 1,000 vehicles per hour.

[0044] S2.10: Calculate q using formulas (24)-(25) r (k+1) and g(k+1), after the calculation is completed, go to step 3;

[0045]

[0046] in, The saturation flow of the entrance ramp is 1,000 vehicles per hour.

[0047] Step 3: Update the speed limit value set in the variable speed limit control area to VSL(k+1) kilometers per hour, and update the confluence time of the entrance ramp control area to g(k+1) seconds;

[0048] Step 4: After the kth coordinated control cycle is completed, enter the k+1th coordinated control cycle, and control the k+1th coordinated control cycle according to steps 2 to 3, and repeat this cycle to achieve coordinated control of port collection and distribution highways. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flow chart of the coordinated control method of the port collection and distribution expressway of the present invention;

[0050] Figure 2 It is a structural schematic diagram of the control scene in the coordinated control method of the port collection and distribution highway of the present invention;

[0051] FIG3( a ) is a graph showing the weight results of the highways in the coordinated control method for the port collection and distribution highways of the present invention;

[0052] FIG3( b ) is a weight result diagram of the entrance ramp in the coordinated control method of the port collection and distribution highway of the present invention;

[0053] Figure 4 It is a bottleneck occupancy result diagram in the port collection and distribution highway collaborative control method of the present invention;

[0054] Figure 5 It is a result diagram of the number of entrance ramp queues in the coordinated control method of the port collection and distribution highway of the present invention;

[0055] Figure 6 It is a result diagram of total travel time in the coordinated control method of the port collection and distribution highway of the present invention;

[0056] Figure 7This is a result diagram of total pollutant emissions in the coordinated control method for port collection and distribution highways of the present invention. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below with reference to the accompanying drawings.

[0058] Embodiment 1: A method for collaborative control of a port collection and distribution highway, based on the traffic flow information of the current collaborative control cycle, uses a feedback control mechanism to first calculate the expected bottleneck flow, and divides the bottleneck expected flow into highway weighted flow and entrance ramp weighted flow according to the occupancy weights of the highway and the entrance ramp, and then calculates the expected queue management flow, and by judging the relationship between the variable speed limit change state, the entrance ramp weighted flow and the queue management expected flow, selects different strategies to calculate the speed limit value and the confluence time, uses the currently calculated speed limit value to update the speed limit value of the preset variable speed limit control area, and uses the currently calculated confluence time to update the confluence time of the preset entrance ramp control area, to achieve collaborative control of the current collaborative control cycle, and in this cycle, achieves collaborative control of the port collection and distribution highway.

[0059] In this embodiment, after the entrance ramp control area and the entrance ramp control area are preset, the speed limit value and the merging time can be calculated based on the traffic flow information of the current cooperative control period by using the feedback control mechanism, without the need to build a complex prediction model, saving calculation time and calculation resources, fast response speed, and ensuring the real-time control. The speed limit value and the merging time are calculated by using the feedback control mechanism, and the speed limit value currently calculated is applied to the variable speed limit control area and the merging time currently obtained is applied to the entrance ramp control area in each cooperative control period, so as to achieve the real-time update of the speed limit value of the variable speed limit control area and the real-time update of the merging time of the entrance ramp control area, and the control accuracy is high. In addition, in the process of calculating the speed limit value and the merging time, the highway weighted flow and the entrance ramp weighted flow are divided according to the occupancy weights of the highway and the entrance ramp, and the queue management expected flow is calculated. By judging the size relationship between the variable speed limit change state, the entrance ramp weighted flow and the queue management expected flow, different strategies are matched to calculate the speed limit value and the merging time, so as to effectively adapt to the port collection and distribution highway with strong flow fluctuation.

[0060] Embodiment 2: Figure 1 As shown, a method for coordinated control of a port collection and distribution highway comprises the following steps:

[0061] Step 1: Divide the port collection and distribution control area into a variable speed limit control area, an acceleration area, a bottleneck area, and an entrance ramp control area. Take the connection point between the entrance ramp and the highway as the starting point, and go against the direction of the highway traffic flow from the starting point l vThe starting point of the variable speed limit control area is at meters. v =1600, the speed of vehicles traveling in the variable speed control area is controlled by the speed limit value set in the variable speed control area; the distance from the starting point to the opposite direction of the highway traffic flow is l a The variable speed limit control area ends at 1 meter, which is also the starting point of the acceleration area. a =400, vehicles entering the acceleration zone are allowed to accelerate; along the direction of the highway traffic flow, the distance from the starting point is l b The end point of the acceleration area is at the same time the starting point of the bottleneck area. b =400, along the direction of traffic flow on the highway, the distance from the starting point is l o The bottleneck area is at the end point, l o =800; Distance from the starting point to the opposite direction of the entrance ramp traffic flow l r The starting point of the entrance ramp control area is at meters. r =630, vehicles entering the entrance ramp control area are controlled by ramp traffic lights, and the connection point between the entrance ramp and the highway is also the end point of the entrance ramp control area; a first loop coil detector is installed at the end point of the variable speed limit control area, and the first loop coil detector is used to use electromagnetic sensing technology to obtain the highway detection flow in real time and transmit it to the control system. When each cooperative control cycle is started, the first loop coil detector outputs the highway detection flow of the cooperative control cycle to the control system;

[0062] A second loop coil detector is installed at the starting point of the entrance ramp control area. The second loop coil detector is used to obtain the entrance ramp demand flow in real time by using electromagnetic sensing technology and transmit it to the control system. When each cooperative control cycle is started, the second loop coil detector outputs the entrance ramp demand flow of the cooperative control cycle to the control system;

[0063] A first video vehicle detector is installed at the starting point of the bottleneck area. The first video vehicle detector is used to obtain the bottleneck occupancy rate in real time by using video detection technology and transmit it to the control system. When each cooperative control cycle is started, the first video vehicle detector outputs the bottleneck occupancy rate of the cooperative control cycle to the control system.

[0064] A second video vehicle detector is installed at the starting point of the variable speed limit control area. The second video vehicle detector is used to obtain the variable speed limit control area occupancy rate in real time by using video detection technology and transmit it to the control system. When each cooperative control cycle is started, the second video vehicle detector outputs the variable speed limit control area occupancy rate of the cooperative control cycle to the control system.

[0065] A third video vehicle detector is installed at the starting point of the entrance ramp control area. The third video vehicle detector is used to obtain the entrance ramp control area occupancy rate and the number of entrance ramp queues in real time by using video detection technology and transmit them to the control system. When each cooperative control cycle is started, the third video vehicle detector outputs the entrance ramp control area occupancy rate and the number of entrance ramp queues of the cooperative control cycle to the control system;

[0066] A fourth video vehicle detector is installed at the end of the bottleneck area. The fourth video vehicle detector is used to obtain the total driving time of the port collection and distribution control area in real time by using video detection technology and transmit it to the control system. When each collaborative control cycle is started, the fourth video vehicle detector outputs the total driving time of the port collection and distribution control area of ​​the collaborative control cycle to the control system;

[0067] An air quality detector is installed at the end of the bottleneck area. The air quality detector uses sensors and 32-bit high-precision CPU processing to obtain the total pollutant emissions in the port collection and distribution control area in real time and transmit it to the control system. When each collaborative control cycle is started, the air quality detector outputs the total pollutant emissions in the port collection and distribution control area of ​​the collaborative control cycle to the control system;

[0068] In the control system, each cooperative control cycle is set to T c Seconds, T c =30, after the control starts, the first T c The cycle number of seconds is recorded as 1, and this cycle is called the first cooperative control cycle. c seconds, the number of cycles is increased by 1; the variable speed limit is set to last for n cooperative control cycles, n = 4, if the number of cycles of a certain cooperative control cycle is an integer multiple of n, the variable speed limit change state of the cooperative control cycle is recorded as 1, otherwise, the variable speed limit change state of the cooperative control cycle is recorded as 0; after the kth T c The period of seconds is the kth cooperative control period, k = 1, 2, 3, ...;

[0069] Step 2: When entering the kth coordinated control cycle, the kth coordinated control begins. The specific control process is:

[0070] S2.1: Set the bottleneck expected flow of the k+1th cooperative control cycle to vehicles per hour, determine whether the current value of k is equal to 1. If so, use formula (1) to calculate If not, use formula (2) to calculate

[0071]

[0072] Among them, KP Kilometers per hour is the proportional coefficient, 0≤K P ≤10,K I Kilometers per hour is the integration coefficient, 10≤K I ≤15; Vehicles per kilometer is the bottleneck occupancy rate setting value, q cap vehicles per hour is the highway capacity, q cap =3470;o out (k) The bottleneck occupancy rate of the kth cooperative control cycle per kilometer, obtained by the first video vehicle detector; out (k-1) vehicles per kilometer is the bottleneck occupancy rate of the k-1th cooperative control cycle, obtained by the first video vehicle detector; when k ≥ 2, is the bottleneck expected flow of the kth cooperative control cycle. When k = 1,

[0073] S2.2: Set the freeway weight of the k+1th coordinated control cycle to w1(k+1); the entrance ramp weight to w2(k+1); the freeway weighted flow rate to c(k+1) vehicles per hour; the entrance ramp weighted flow rate to r(k+1) vehicles per hour; use formulas (3)-(6) to calculate w1(k+1), w2(k+1), c(k+1) and r(k+1) respectively:

[0074]

[0075] Among them, Λ c is the number of lanes of the port collection and distribution highway, Λ r is the number of lanes on the entrance ramp of the port collection and distribution expressway; μ c is the priority coefficient of the port collection and distribution highway, μ r is the priority coefficient of the entrance ramp of the port collection and distribution expressway, 7≤μ c ≤9, 1≤μ r ≤3; o c (k) The occupancy rate of the variable speed limit control area per kilometer for the kth cooperative control cycle, obtained by the second video vehicle detector; r (k) The occupancy rate of the entrance ramp control area per kilometer for the kth cooperative control cycle, obtained by the third video vehicle detector;

[0076] S2.3: Set the expected flow of queue management in the k+1th cooperative control cycle to vehicles per hour, calculated using formula (7)

[0077]

[0078] in, Vehicle is the set value of the queue quantity, d(k) vehicles per hour is the entrance ramp demand flow in the kth cooperative control cycle, obtained by the second ring coil detector; w(k) vehicles is the number of entrance ramp queues in the kth cooperative control cycle, obtained by the third video vehicle detector;

[0079] S2.4: Set the expected traffic volume of the highway in the k+1th cooperative control cycle to Vehicles per hour; Actual highway traffic volume q c (k+1) vehicles per hour; the actual flow rate of the entrance ramp is q r (k+1) vehicles per hour; the expected speed limit is VSL f (k+1) kilometers per hour; the actual speed limit value is VSL(k+1) kilometers per hour; the confluence time is g(k+1) seconds; determine whether the variable speed limit change state N(k) of the kth cooperative control cycle is equal to 1, if yes, proceed to step S2.5, if not, proceed to step S2.8;

[0080] S2.5: Determine whether r(k+1) is greater than If yes, go directly to step S2.6, if no, go directly to step S2.7;

[0081] S2.6: Calculated using formulas (8)-(13) VSL f (k+1), VSL(k+1), q c (k+1),q r (k+1) and g(k+1), after the calculation is completed, go to step 3;

[0082]

[0083]

[0084]

[0085]

[0086] Among them, K R The integration coefficient is per kilometer, K R =0.18;Δ max km / h is the maximum value of the speed limit value set in the variable speed control area, Δ max =20; The saturation flow of the entrance ramp is 1,000 vehicles per hour. When k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period. When k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector;

[0087] S2.7: Calculate q using formulas (14)-(19) r (k+1), g(k+1), VSL f (k+1), VSL(k+1) and q c (k+1), after the calculation is completed, go to step 4;

[0088]

[0089] Among them, K R The integration coefficient is per kilometer, K R =0.18;Δ max km / h is the maximum value of the speed limit value set in the variable speed control area, Δ max =20; The saturation flow of the entrance ramp is 1,000 vehicles per hour. When k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period. When k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector;

[0090] S2.8: First, use formulas (20)-(21) to calculate VSL(k+1) and q c (k+1), and then determine whether r(k+1) is greater than If yes, go directly to step S2.9, if no, go directly to step S2.10;

[0091] VSL(k+1)=VSL(k) (20)

[0092]

[0093] Wherein, when k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period, and when k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector;

[0094] S2.9: Calculate q using formulas (22)-(23) r (k+1) and g(k+1), after the calculation is completed, go to step 3;

[0095]

[0096] in, The saturation flow of the entrance ramp is 1,000 vehicles per hour.

[0097] S2.10: Calculate q using formulas (24)-(25) r (k+1) and g(k+1), after the calculation is completed, go to step 3;

[0098]

[0099] in, The saturation flow of the entrance ramp is 1,000 vehicles per hour.

[0100] Step 3: Update the speed limit value set in the variable speed limit control area to VSL(k+1) kilometers per hour, and update the confluence time of the entrance ramp control area to g(k+1) seconds;

[0101] Step 4: After the kth coordinated control cycle is completed, enter the k+1th coordinated control cycle, and control the k+1th coordinated control cycle according to steps 2 to 3, and repeat this cycle to achieve coordinated control of port collection and distribution highways.

[0102] In this embodiment, in the SUMO simulation scenario, the following is constructed: Figure 2 The control scenario of the coordinated control method for port collection and distribution highways is shown in FIG. Figure 2 It can be seen that c =3,Λ r =1; set K P = 0 kilometers per hour, K I = 15 km / h, Vehicle per kilometer, μ c =7,μ r =3.

[0103] Take the 120th coordinated control cycle as an example: According to the actual measurement, o out (119) = 34 vehicles per kilometer, o out (120) = 35 vehicles per kilometer, o c (120) = 15 vehicles per kilometer, o r (120) = 50 vehicles per kilometer, d(120) = 600 vehicles per hour, w(120) = 21 vehicles, Vehicles per hour; calculated based on the 119th coordinated control cycle vehicles per hour, VSL(120) = 60 kilometers per hour; when entering the 120th cooperative control cycle, the 120th cooperative control begins. Since 120 is not equal to 1, formula (2) is used to obtain vehicles per hour; using formula (3)-(6) we get w1(121)=0.69, w1(121)=0.31, c(121)=906 vehicles per hour, r(121)=407 vehicles per hour; using formula (7) we get vehicles per hour; it is determined that the variable speed limit change state N(120)=1 in the 120th cooperative control cycle, so it goes to step S2.5; it is determined that So go to step S2.6; use formula (8) to get vehicles per hour, and VSL is obtained by using formula (9) f (121) = 30 km / h. Using formula (10)-(11), we get VSL (121) = 40 km / h. c (121) = 1017 vehicles per hour, using formula (12)-(13) to get q r (121) = 296 vehicles per hour, g(121) = 9 seconds; the speed limit value set in the variable speed limit control area is updated to be equal to VSL(121) = 40 kilometers per hour, and the confluence time of the entrance ramp control area is updated to be equal to g(121) = 9 seconds; after the 120th coordinated control cycle is completed, the 121st coordinated control cycle is entered, and the 121st coordinated control cycle is controlled according to steps 2 to 3, and this cycle is repeated to realize the coordinated control of the port collection and distribution highway.

[0104] This embodiment selects the results of the 1st to 240th control cycles in the coordinated control process of the port collection and distribution highway to display: the weight result of the highway in the coordinated control method of the port collection and distribution highway is shown in Figure 3(a), and the weight result of the entrance ramp in the coordinated control method of the port collection and distribution highway is shown in Figure 3(b); the bottleneck occupancy result in the coordinated control method of the port collection and distribution highway is shown in Figure 3(c). Figure 4 As shown in the figure; the number of entrance ramp queues in the coordinated control method of port collection and distribution highway is shown in the figure Figure 5 As shown in the figure; the total travel time results of the coordinated control method of port collection and distribution highway are as follows Figure 6 The total pollutant emissions in the coordinated control method of port collection and distribution highways are shown in Figure 7 shown.

[0105] like Figure 4As shown in Figure 2, when the bottleneck occupancy rate increases rapidly without control, the bottleneck occupancy rate in the port collection and distribution highway collaborative control method is obviously controlled and reduced, indicating that the port collection and distribution highway collaborative control method has a fast response speed; Figure 5 As shown, the number of entry ramp queues is effectively limited to the set value The number of vehicles is less than 100, which indicates that the control accuracy of the coordinated control method for port collection and distribution highway is high; Figure 6 In the study, the total driving time without control was as high as 10 vehicle hours, while the maximum driving time of the port collection and distribution highway collaborative control method was only 7 vehicle hours, and the total driving time was optimized by 30%. Figure 7 In the experiment, the total pollutant emissions without control were as high as 55 kg, while the maximum emission of the coordinated control method for port collection and distribution highways was only 45 kg, and the total pollutant emissions were optimized by 18%, indicating that the coordinated control method for port collection and distribution highways can effectively adapt to port collection and distribution highways with strong traffic fluctuations.

[0106] The method for coordinated control of the port collection and distribution expressway of the present invention can use a computer as a control platform, set the control system in the computer, and set the LED variable speed limit sign and the ramp entrance indicator light to be connected to the control system. The LED variable speed limit sign is installed at the starting point of the variable speed limit control area, the control system outputs the speed limit value set in the variable speed limit control area through radio wave technology and displays it on the LED variable speed limit sign, and the speed limit value is updated once in each coordinated control cycle. The ramp entrance indicator light is installed at the end of the entrance ramp control area, and the control system outputs the confluence time of the entrance ramp control area through radio wave technology and displays it on the ramp entrance indicator light, and the confluence time is updated once in each coordinated control cycle, thereby realizing coordinated control of the port collection and distribution expressway.

[0107] In summary, the coordinated control method for the port collection and distribution highway of the present invention has a fast response speed, high control accuracy, and can effectively adapt to the port collection and distribution highway with strong traffic fluctuations.

Claims

1. A coordinated control method for port collection and distribution highways, characterized in that Based on the traffic flow information of the current collaborative control cycle, the feedback control mechanism is used to first calculate the bottleneck expected flow, and the bottleneck expected flow is divided into highway weighted flow and entrance ramp weighted flow according to the occupancy weights of the highway and the entrance ramp. Then the queue management expected flow is calculated, and by judging the relationship between the variable speed limit change state, the entrance ramp weighted flow and the queue management expected flow, different strategies are selected to calculate the speed limit value and the confluence time. The speed limit value calculated currently is used to update the speed limit value of the preset variable speed limit control area, and the confluence time calculated currently is used to update the confluence time of the preset entrance ramp control area, so as to realize the collaborative control of the current collaborative control cycle. In this way, the collaborative control of the port collection and distribution highway is realized.

2. A coordinated control method for port collection and distribution highways according to claim 1, characterized in that The following steps are involved: Step 1: Divide the port collection and distribution control area into a variable speed limit control area, an acceleration area, a bottleneck area, and an entrance ramp control area. Take the connection point between the entrance ramp and the highway as the starting point, and go against the direction of the highway traffic flow from the starting point to the bottleneck area. v The starting point of the variable speed limit control area is at meters. v =1600, the speed of vehicles traveling in the variable speed control area is controlled by the speed limit value set in the variable speed control area; the distance from the starting point to the opposite direction of the highway traffic flow is l a The variable speed limit control area ends at 1 meter, which is also the starting point of the acceleration area. a =400, vehicles entering the acceleration zone are allowed to accelerate; The distance from the starting point along the direction of traffic flow on the highway b The end point of the acceleration area is at the same time the starting point of the bottleneck area. b =400, along the direction of traffic flow on the highway, the distance from the starting point is l o The bottleneck area is at the end point, l o =800; Distance from the starting point to the opposite direction of the entrance ramp traffic flow l r The starting point of the entrance ramp control area is at meters. r =630, vehicles entering the entrance ramp control area are controlled by ramp traffic lights, and the connection point between the entrance ramp and the highway is also the end point of the entrance ramp control area; A first loop coil detector is installed at the end of the variable speed limit control area. The first loop coil detector is used to obtain the highway detection flow in real time by using electromagnetic sensing technology and transmit it to the control system. When each cooperative control cycle is started, the first loop coil detector outputs the highway detection flow of the cooperative control cycle to the control system. A second loop coil detector is installed at the starting point of the entrance ramp control area. The second loop coil detector is used to obtain the entrance ramp demand flow in real time by using electromagnetic sensing technology and transmit it to the control system. When each cooperative control cycle is started, the second loop coil detector outputs the entrance ramp demand flow of the cooperative control cycle to the control system; A first video vehicle detector is installed at the starting point of the bottleneck area. The first video vehicle detector is used to obtain the bottleneck occupancy rate in real time by using video detection technology and transmit it to the control system. When each cooperative control cycle is started, the first video vehicle detector outputs the bottleneck occupancy rate of the cooperative control cycle to the control system. A second video vehicle detector is installed at the starting point of the variable speed limit control area. The second video vehicle detector is used to obtain the variable speed limit control area occupancy rate in real time by using video detection technology and transmit it to the control system. When each cooperative control cycle is started, the second video vehicle detector outputs the variable speed limit control area occupancy rate of the cooperative control cycle to the control system. A third video vehicle detector is installed at the starting point of the entrance ramp control area. The third video vehicle detector is used to obtain the entrance ramp control area occupancy rate and the number of entrance ramp queues in real time by using video detection technology and transmit them to the control system. When each cooperative control cycle is started, the third video vehicle detector outputs the entrance ramp control area occupancy rate and the number of entrance ramp queues of the cooperative control cycle to the control system; A fourth video vehicle detector is installed at the end of the bottleneck area. The fourth video vehicle detector is used to obtain the total driving time of the port collection and distribution control area in real time by using video detection technology and transmit it to the control system. When each collaborative control cycle is started, the fourth video vehicle detector outputs the total driving time of the port collection and distribution control area of ​​the collaborative control cycle to the control system; An air quality detector is installed at the end of the bottleneck area. The air quality detector uses sensors and 32-bit high-precision CPU processing to obtain the total pollutant emissions in the port collection and distribution control area in real time and transmit it to the control system. When each collaborative control cycle is started, the air quality detector outputs the total pollutant emissions in the port collection and distribution control area of ​​the collaborative control cycle to the control system; In the control system, each cooperative control cycle is set to T c Seconds, T c =30, after the control starts, the first T c The cycle number of seconds is recorded as 1, and this cycle is called the first cooperative control cycle. c seconds, the number of cycles is increased by 1; the variable speed limit is set to last for n cooperative control cycles, n = 4, if the number of cycles of a certain cooperative control cycle is an integer multiple of n, the variable speed limit change state of the cooperative control cycle is recorded as 1, otherwise, the variable speed limit change state of the cooperative control cycle is recorded as 0; after the kth T c The period of seconds is the kth cooperative control period, k = 1, 2, 3, ...; Step 2: When entering the kth cooperative control cycle, the kth cooperative control begins. The specific control process is: S2.1: Set the bottleneck expected flow of the k+1th cooperative control cycle to vehicles per hour, determine whether the current value of k is equal to 1. If so, use formula (1) to calculate If not, use formula (2) to calculate Among them, K P Kilometers per hour is the proportional coefficient, 0≤K P ≤10,K I Kilometers per hour is the integration coefficient, 10≤K I ≤15; Vehicles per kilometer is the bottleneck occupancy rate setting value, q cap The capacity of the expressway is qcap = 3470 vehicles per hour; out (k) The bottleneck occupancy rate of the kth cooperative control cycle per kilometer, obtained by the first video vehicle detector; out (k-1) vehicles per kilometer is the bottleneck occupancy rate of the k-1th cooperative control cycle, obtained by the first video vehicle detector; when k ≥ 2, is the bottleneck expected flow of the kth cooperative control cycle. When k = 1, S2.2: Set the freeway weight of the k+1th coordinated control cycle to w1(k+1); the entrance ramp weight to w2(k+1); the freeway weighted flow rate to c(k+1) vehicles per hour; the entrance ramp weighted flow rate to r(k+1) vehicles per hour; use formulas (3)-(6) to calculate w1(k+1), w2(k+1), c(k+1) and r(k+1) respectively: Among them, Λ c is the number of lanes of the port collection and distribution highway, Λ r is the number of lanes on the entrance ramp of the port collection and distribution expressway; μ c is the priority coefficient of the port collection and distribution highway, μ r is the priority coefficient of the entrance ramp of the port collection and distribution expressway, 7≤μ c ≤9, 1≤μ r ≤3; o c (k) The occupancy rate of the variable speed limit control area per kilometer for the kth cooperative control cycle, obtained by the second video vehicle detector; r (k) The occupancy rate of the entrance ramp control area per kilometer for the kth cooperative control cycle, obtained by the third video vehicle detector; S2.3: Set the expected flow of queue management in the k+1th cooperative control cycle to vehicles per hour, calculated using formula (7) in, Vehicle is the set value of the queue quantity, d(k) vehicles per hour is the entrance ramp demand flow in the kth cooperative control cycle, obtained by the second ring coil detector; w(k) vehicles is the number of entrance ramp queues in the kth cooperative control cycle, obtained by the third video vehicle detector; S2.4: Set the expected traffic volume of the highway in the k+1th cooperative control cycle to Vehicles per hour; Actual highway traffic volume q c (k+1) vehicles per hour; the actual flow rate of the entrance ramp is q r (k+1) vehicles per hour; the expected speed limit is VSL f (k+1) kilometers per hour; the actual speed limit value is VSL(k+1) kilometers per hour; the confluence time is g(k+1) seconds; determine whether the variable speed limit change state N(k) of the kth cooperative control cycle is equal to 1, if yes, proceed to step S2.5, if not, proceed to step S2.8; S2.5: Determine whether r(k+1) is greater than If yes, go directly to step S2.6, if no, go directly to step S2.7; S2.6: Calculated using formulas (8)-(13) VSL f (k+1), VSL(k+1), q c (k+1),q r (k+1) and g(k+1), after the calculation is completed, go to step 3; Among them, K R The integration coefficient is per kilometer, K R =0.18;Δ max km / h is the maximum value of the speed limit value set in the variable speed control area, Δ max =20; The saturation flow of the entrance ramp is 1,000 vehicles per hour. When k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period. When k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector; S2.7: Calculate q using formulas (14)-(19) r (k+1), g(k+1), VSL f (k+1), VSL(k+1) and q c (k+1), after the calculation is completed, go to step 4; Among them, K R The integration coefficient is per kilometer, K R =0.18;Δ max km / h is the maximum value of the speed limit value set in the variable speed control area, Δ max =20; The saturation flow of the entrance ramp is 1,000 vehicles per hour. When k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period. When k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector; S2.8: First, use formulas (20)-(21) to calculate VSL(k+1) and q c (k+1), and then determine whether r(k+1) is greater than If yes, go directly to step S2.9, if no, go directly to step S2.10; VSL(k+1)=VSL(k) (20) Wherein, when k ≥ 2, VSL (k) kilometers per hour is the speed limit value set at the variable speed limit control area of ​​the kth cooperative control period, and when k = 1, VSL (k) = 120; The highway detection flow of vehicles per hour is the kth cooperative control cycle, which is obtained by the first loop coil detector; S2.9: Calculate q using formulas (22)-(23) r (k+1) and g(k+1), after the calculation is completed, go to step 3; Among them, q r sat The saturation flow of the entrance ramp is 1,000 vehicles per hour. S2.10: Calculate q using formulas (24)-(25) r (k+1) and g(k+1), after the calculation is completed, go to step 3; in, The saturation flow of the entrance ramp is 1,000 vehicles per hour. Step 3: Update the speed limit value set in the variable speed limit control area to VSL(k+1) kilometers per hour, and update the confluence time of the entrance ramp control area to g(k+1) seconds; Step 4: After the kth coordinated control cycle is completed, enter the k+1th coordinated control cycle, and control the k+1th coordinated control cycle according to steps 2 to 3, and repeat this cycle to achieve coordinated control of port collection and distribution highways.

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