Induction-based optimization control method based on dynamic changes in traffic flow and inter-vehicle distance

Abstract

This invention discloses a sensing optimization control method based on dynamic changes in traffic flow and vehicle-to-vehicle distance. The method includes: adjusting the initial green light duration for a phase based on critical waiting traffic flow data collected by a remote strategic detector before the phase is released; adjusting the vehicle flow cutoff distance for the releasing phase based on the accumulated vehicle delay time, queue length, and queue length of the currently released phase, and timing the phase's sensing extension time and cutoff distance time; optimizing the maximum green light duration for a phase before the next cycle's release based on the phase's continuous release termination status within a cycle; and timing and resetting the maximum green light duration for the phase based on whether there are available conflict phase release requests for the currently operating phase. This invention can eliminate the impact of changes in traffic flow and vehicle-to-vehicle distance by collecting real-time traffic flow data and traffic status, improving the effective utilization rate of green light duration, and reducing delays.

Description

Technical Field

[0001] This invention belongs to the field of traffic signal control technology, specifically a sensing optimization control method based on the dynamic changes in traffic flow and vehicle-to-vehicle distance. Background Technology

[0002] Inductive control involves traffic flow detectors detecting traffic demand at intersections in real time, and the traffic signal controller automatically adjusts the pre-set traffic signal control scheme to match signal timing with traffic demand.

[0003] The main problems currently exist as follows:

[0004] (1) The initial time for release is fixed. When there are no tactical detectors at the intersection and only strategic detectors are present, the minimum green light needs to be long enough to allow all vehicles queuing between the stop line and the detector to pass through the intersection, resulting in the green light being left empty in the case of low traffic flow.

[0005] (2) The timing interval between the phase cut-off time and the extension time are not distinguished. When a larger timing interval is used, the queue can be cleared at the initial release of the phase, but the subsequent low-speed vehicles can still extend the phase release, reducing the green light utilization rate. When a smaller timing interval is used, the release may be terminated too early due to the slow speed of the queue.

[0006] (3) The maximum green is fixed, lacks flexibility, and cannot adapt to the impact of dynamic changes in traffic flow.

[0007] (4) The maximum green starts timing from the time the phase is released, which causes the current phase to end prematurely when there is still a request in the current phase while other phases have no requests or delayed requests. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of the existing technology by providing a sensing optimization control method based on the dynamic changes in traffic flow and vehicle-to-vehicle distance.

[0009] The technical solution to achieve the objective of this invention is: a sensing optimization control method based on dynamic changes in traffic flow and inter-vehicle time intervals, the method comprising the following steps:

[0010] Step 1: Based on the key waiting traffic flow data of the phase before the release, the remote strategic detector is used to calculate the phase's initial green light duration;

[0011] Step 2: Based on the cumulative vehicle delay time and queue length of the conflicting phase, and the queue length of the current release phase, adjust the vehicle flow cut-off time interval of the release phase, and time the induction extension time and cut-off time interval of the timing phase respectively.

[0012] Step 3: Based on the continuous release termination status of the phase in the cycle, optimize and adjust the maximum green of the phase before the release in the next cycle;

[0013] Step 4: Based on whether there are any conflicting phase release requests that can be served in the current running phase, time and reset the maximum green of the phase.

[0014] Furthermore, the key waiting traffic flow data for the phase mentioned in step 1 before the green light is released is specifically as follows: for a phase corresponding to a single lane, all arriving vehicles from the end of the previous green light cycle to the start of the current green light cycle are the key waiting traffic flow data; for a multi-lane phase, the maximum number of arriving waiting vehicles is selected from each lane as the key waiting traffic flow data.

[0015] Furthermore, the correction of the initial green light duration for phase clearance mentioned in step 1 specifically includes:

[0016] The initial green light duration is dynamically adjusted based on the current critical waiting traffic flow data for each phase, and is subject to minimum and maximum initial green light constraints. The formula for calculating the initial green light duration is as follows:

[0017]

[0018] G v =MAX(MIN(t) d +i*c, G maxv ), G min )

[0019] Among them, G maxv For the maximum initial green, t d The vehicle start-up delay time, where i is the increment step, D is the distance between the stop line and the downstream edge of the nearest far-end detector area, and L is the vehicle start-up delay time. v For the default vehicle length, G v G represents the initial green light interval for the phase, c represents the critical waiting traffic volume before the phase is released, and G represents the initial green light interval for the phase. min Minimum green constraint time for safety.

[0020] Furthermore, the unit increment is the time it takes for the vehicle to pass the stop line.

[0021] Furthermore, step 2, adjusting the time interval between traffic flow cutoff points in the release phase, specifically includes:

[0022] The formula for calculating the time interval between traffic flow cutoff points is as follows:

[0023] g = MAX(L) conflict -L release ,0)

[0024] Pv =MAX(P i -Δp*g*(T now -T begin ), P min )

[0025] Where g is the rate at which the time interval between traffic flow cutoff points decreases, and L conflict L represents the queue length level for conflict phases. release For the queue length level of the phase being released, P v To cut off the time interval between trains in a variable traffic flow, P i The initial cutoff time interval is T, where Δp is the unit cutoff time interval decrease value. now At the current time point, T begin P is the point in time when the accumulated time of conflict phase delay reaches a set value. min Minimum cutoff time interval constraint.

[0026] Furthermore, the induction extension time and truncation time interval of the timing phase mentioned in step 2 specifically include:

[0027] The timing sensing extension time is used to extend the phase release, and the timing cutoff workshop time interval time is used to initialize the sensing extension timing.

[0028] When a phase begins to release traffic, the set induction extension time is used as the upper limit of the initial traffic flow cutoff time. When the accumulated delay time of the conflicting phase reaches the preset value, the upper limit of the traffic flow cutoff time for the releasing phase is reduced according to the queue length of the releasing phase and the conflicting phase. When the timer for the running phase has not reached the upper limit of the cutoff time, it indicates that there is a release request, and the induction extension time and cutoff time timing are restarted. When the cutoff timer for the running phase reaches the upper limit, subsequent vehicle requests cannot initialize the induction extension time. The remaining induction extension time can ensure the safe release of the last valid request vehicle at the time of cutoff.

[0029] Furthermore, step 3, based on the continuous release termination status of the phase in the cycle, optimizes and adjusts the maximum green of the phase before the release in the next cycle. Specifically, this includes: statistically analyzing the phase end status of each cycle; when a phase reaches the maximum green output twice consecutively, adding a dynamic step size to the running maximum green until the running maximum green is greater than the upper limit of the dynamic maximum green, then using the upper limit of the dynamic maximum green as a constraint for operation; when a phase ends prematurely due to exceeding the cutoff time interval twice consecutively, subtracting a dynamic step size from the running maximum green until the running maximum green is less than the lower limit of the dynamic maximum green, then using the lower limit of the dynamic maximum green as a constraint for operation; if a phase ends prematurely in one cycle and reaches the maximum green in the next cycle, or vice versa, then the running maximum green will not change.

[0030] Furthermore, the timing of the maximum green phase in step 4 specifically includes:

[0031] When there is no available release request for a conflicting phase, the operating phase will not time the maximum green timer. That is, the operating phase will continue to allow traffic to pass as long as the vehicle spacing is less than the time interval between traffic cutoff points. When there is an available release request for a conflicting phase, the operating phase will start timing the maximum green timer and will end the current operating phase's release once the maximum green timer reaches its limit. If the available release request for a conflicting phase disappears during the maximum green timer, the maximum green timer will be reset and maintained until the conflicting phase detects a request again and restarts timing.

[0032] Compared with the prior art, the significant advantages of this invention are:

[0033] 1) For phase-critical waiting traffic flow data, for multi-lane phases, the maximum number of arriving waiting vehicles in each lane is selected as the critical waiting traffic flow data to avoid the abnormal initial green light release problem caused by the accumulation of multi-lane data.

[0034] 2) When adjusting the cut-off time interval of the traffic flow in the release phase, a larger cut-off time interval is set at the beginning of the green light. This ensures that the queuing vehicles are still at a low speed at the initial release time and can pass through the intersection smoothly before the time interval reaches saturation. When the accumulated delay time of the conflict phase reaches a certain value, the cut-off time interval is gradually reduced to the saturation time interval. This ensures that the vehicle spacing in the release phase does not meet the saturation spacing and the release phase is cut off in time, thereby reducing the time spent serving traffic flow below saturation and reducing vehicle delays.

[0035] 3) This invention distinguishes between the induction extension interval and the cutoff interval of the phase, and uses the timing of the induction extension time to extend the phase release, and the timing of the cutoff interval time to initialize the induction extension timing, thereby improving the utilization rate of green lights while ensuring the safe release of vehicles.

[0036] 4) The phase maximum green time method proposed in this invention takes into account both the timeliness and fairness of the allocation of time resources for each phase of the intersection. When there is no competitive demand for passage, the current phase can be allowed to pass indefinitely; when there is competition, the maximum allowable passage time of the current phase must be limited.

[0037] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0038] Figure 1 This is a flowchart of the inductive optimization control method based on the dynamic changes in traffic flow and inter-vehicle time distance of the present invention.

[0039] Figure 2This is a schematic diagram of waiting traffic flow before multi-lane phase release in one embodiment.

[0040] Figure 3 This is a schematic diagram of traffic flow and release for the release phase and conflict waiting phase in one embodiment.

[0041] Figure 4 This is a schematic diagram illustrating the relationship between the extended timer and the truncated workshop time interval timer in one embodiment.

[0042] Figure 5 This is a schematic diagram of the phase dynamic maximum green adjustment in one embodiment.

[0043] Figure 6 This is a schematic diagram of the maximum green phase timing in one embodiment. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0046] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0047] In one embodiment, combined Figure 1 A sensing optimization control method based on dynamic changes in traffic flow and inter-vehicle time distance is provided. The method includes the following steps:

[0048] Step 1: Based on the key waiting traffic flow data of the phase before the release, the remote strategic detector is used to calculate the phase's initial green light duration;

[0049] Step 2: Based on the cumulative vehicle delay time and queue length of the conflicting phase, and the queue length of the current release phase, adjust the vehicle flow cutoff time interval of the release phase, and time the induction extension time and cutoff time interval of the timing phase respectively, so as to ensure the safe release of the last valid request vehicle at the cutoff time while obtaining more efficient output.

[0050] Step 3: Based on the continuous release termination status of the phase in the cycle, optimize and adjust the maximum green of the phase before the release in the next cycle;

[0051] Step 4: Based on whether there are any conflicting phase release requests that can be served in the current running phase, time and reset the maximum green of the phase.

[0052] Furthermore, in one embodiment, the key waiting traffic flow data of the phase before the release in step 1 is specifically as follows: for the phase corresponding to a single lane, all arriving vehicles from the end of the previous green light cycle to the release of the current green light cycle are the key waiting traffic flow data; for multi-lane phases, the maximum number of arriving waiting vehicles in each lane is selected as the key waiting traffic flow data to avoid the abnormal initial green light release problem caused by the accumulation of multi-lane data.

[0053] Furthermore, in one embodiment, the step 1 of correcting the initial green light duration for phase clearance specifically includes:

[0054] The initial green light duration is dynamically adjusted based on the current critical waiting traffic flow data for each phase, and is subject to minimum and maximum initial green light constraints. The formula for calculating the initial green light duration is as follows:

[0055]

[0056] G v =MAX(MIN(t) d +i*c,G maxv ),G min )

[0057] Among them, G maxv For the maximum initial green, t d The vehicle start-up delay time, where i is the increment step, typically the time it takes for the vehicle to cross the stop line, D is the distance between the stop line and the downstream edge of the nearest far-end detector area, and L is the vehicle start-up delay time. v For the default vehicle length, G v G represents the initial green light interval for the phase, c represents the critical waiting traffic volume before the phase is released, and G represents the initial green light interval for the phase. min Minimum green constraint time for safety.

[0058] Furthermore, in one embodiment, step 2, adjusting the vehicle flow cutoff time interval in the release phase, specifically includes:

[0059] When the green light begins, a relatively large cutoff interval is set for the traffic flow. This ensures that queuing vehicles are still moving at low speeds at the initial release time and can pass through the intersection smoothly before the cutoff interval reaches saturation. As the accumulated delay time of conflicting phases reaches a certain value, the cutoff interval is gradually reduced to the saturation interval. This ensures that if the spacing between vehicles in the release phase does not meet the saturation spacing, the release phase is promptly cut off, thereby reducing the time spent serving traffic flows below saturation and reducing vehicle delays.

[0060] The formula for calculating the time interval between traffic flow cutoff points is as follows:

[0061] g = MAX(L) conflict -L release ,0)

[0062] P v =MAX(P i -Δp*g*(T now -T begin ), P min )

[0063] Where g is the rate at which the time interval between traffic flow cutoff points decreases, and L conflict L represents the queue length level for conflict phases. release For the queue length level of the phase being released, P v To cut off the time interval between trains in a variable traffic flow, P i The initial cutoff time interval is T, where Δp is the unit cutoff time interval decrease value. now At the current time point, T begin P is the point in time when the accumulated time of conflict phase delay reaches a set value. min Minimum cutoff time interval constraint.

[0064] Furthermore, in one embodiment, the induction extension time and truncation time interval of the timing phase in step 2 specifically include:

[0065] The timing sensing extension time is used to extend the phase release, and the timing cutoff workshop time interval time is used to initialize the sensing extension timing.

[0066] When a phase begins to release traffic, the set induction extension time is used as the upper limit of the initial traffic flow cutoff time. When the accumulated delay time of the conflicting phase reaches the preset value, the upper limit of the traffic flow cutoff time for the releasing phase is reduced according to the queue length of the releasing phase and the conflicting phase. When the running phase has not reached the upper limit of the cutoff timer, it indicates that there is a release request, and the induction extension time and cutoff timer are restarted. When the cutoff timer of the running phase reaches the upper limit, subsequent vehicle requests cannot initialize the induction extension time, but the remaining induction extension time can ensure the safe release of the last valid request vehicle at the cutoff time.

[0067] Further, in one embodiment, step 3, based on the continuous release termination state of the phase in the cycle, optimizes and adjusts the maximum green of the phase before the release in the next cycle. Specifically, this includes: statistically analyzing the phase end state of each cycle; when a phase reaches the maximum green output twice consecutively, adding a dynamic step size to the running maximum green until the running maximum green is greater than the upper limit of the dynamic maximum green, then operating with the upper limit of the dynamic maximum green as a constraint; when a phase ends prematurely due to exceeding the cutoff time interval twice consecutively, subtracting a dynamic step size from the running maximum green until the running maximum green is less than the lower limit of the dynamic maximum green, then operating with the lower limit of the dynamic maximum green as a constraint; if a phase ends prematurely in one cycle and reaches the maximum green in the next cycle, and vice versa, then the running maximum green will not change.

[0068] Furthermore, in one embodiment, the timing of the maximum green phase in step 4 specifically includes:

[0069] When there are no serviceable release requests for a conflicting phase, the operating phase will not time the maximum green time; that is, the operating phase will continue to allow traffic as long as the vehicle spacing is less than the time interval between traffic cutoff points. When there are serviceable release requests for a conflicting phase, the operating phase starts timing the maximum green time and ends its release once the maximum green time reaches its limit. If a serviceable release request for a conflicting phase disappears during the maximum green time, the maximum green timer will be reset and maintained until the conflicting phase detects a request again and restarts timing. This timing method balances the timeliness and fairness of the allocation of release time resources for each phase at the intersection. When there is no competing release demand, the current phase can continue to allow traffic; when there is competition, the maximum release time for the current phase must be limited.

[0070] In one embodiment, a sensor-based optimization control system based on dynamic changes in traffic flow and inter-vehicle time distance is provided, the system comprising:

[0071] The first module is used to collect key waiting traffic flow data of the phase before the phase is released based on the statistics of the remote strategic detector, and to correct the initial green light duration of the phase.

[0072] The second module is used to adjust the vehicle flow cut-off time interval of the release phase based on the cumulative vehicle delay time, queue length, and queue length of the current release phase, and to time the induction extension time and cut-off time interval of the timing phase respectively.

[0073] The third module is used to optimize and adjust the maximum green of the phase before the next release cycle based on the continuous release termination status of the phase in the cycle.

[0074] The fourth module is used to time and reset the maximum green of the phase based on whether there is a conflict phase release request that can be served in the current running phase.

[0075] Specific limitations regarding the inductive optimization control system based on dynamic changes in traffic flow and inter-vehicle distance can be found in the limitations of the inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle distance mentioned above, and will not be repeated here. Each module in the aforementioned inductive optimization control system based on dynamic changes in traffic flow and inter-vehicle distance can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0076] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0077] Step 1: Based on the key waiting traffic flow data of the phase before the release, the remote strategic detector is used to calculate the phase's initial green light duration;

[0078] Step 2: Based on the cumulative vehicle delay time and queue length of the conflicting phase, and the queue length of the current release phase, adjust the vehicle flow cut-off time interval of the release phase, and time the induction extension time and cut-off time interval of the timing phase respectively.

[0079] Step 3: Based on the continuous release termination status of the phase in the cycle, optimize and adjust the maximum green of the phase before the release in the next cycle;

[0080] Step 4: Based on whether there are any conflicting phase release requests that can be served in the current running phase, time and reset the maximum green of the phase.

[0081] For specific limitations on each step, please refer to the limitations of the induction optimization control method based on the dynamic changes in traffic flow and inter-vehicle time distance mentioned above, which will not be repeated here.

[0082] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program being implemented when executed by a processor:

[0083] Step 1: Based on the key waiting traffic flow data of the phase before the release, the remote strategic detector is used to calculate the phase's initial green light duration;

[0084] Step 2: Based on the cumulative vehicle delay time and queue length of the conflicting phase, and the queue length of the current release phase, adjust the vehicle flow cut-off time interval of the release phase, and time the induction extension time and cut-off time interval of the timing phase respectively.

[0085] Step 3: Based on the continuous release termination status of the phase in the cycle, optimize and adjust the maximum green of the phase before the release in the next cycle;

[0086] Step 4: Based on whether there are any conflicting phase release requests that can be served in the current running phase, time and reset the maximum green of the phase.

[0087] For specific limitations on each step, please refer to the limitations of the induction optimization control method based on the dynamic changes in traffic flow and inter-vehicle time distance mentioned above, which will not be repeated here.

[0088] As a specific example, the invention will be described in further detail in one embodiment.

[0089] Combination Figure 2 The present invention provides a detailed description of the modified phase initial green light duration.

[0090] Confirm the phase-critical waiting traffic flow data. For Figure 2 For a given phase of a multi-lane road system, the lane with the highest number of arriving vehicles between the end of the previous green light cycle and the start of the current green light cycle is selected as the critical lane. The number of arriving vehicles waiting in the critical lane is used as the critical waiting traffic flow data. Therefore, lane 2 is the critical lane, and the critical waiting traffic flow is 6, avoiding the abnormal initial green light release problem caused by the accumulation of data from multiple lanes.

[0091] Confirm the minimum green light for the phase, the maximum variable initial green light, the increment step, and the initial green light duration. Here, we assume a saturation interval of 2 seconds, and the phase increment step is determined to be 2. Based on the typical minimum green light values ​​for driving overdue in Table 1, the minimum green light for the phase is determined to be 10 seconds. Note that the values ​​in the table are general empirical values, not absolute values. Assuming a vehicle start-up loss delay of 3 seconds, the maximum initial value formula is used:

[0092]

[0093] The maximum variable initial green is obtained as 35s, according to the variable initial value formula:

[0094] G v =MAX(MIN(t) d +i*c,G maxv ),G min )

[0095] The initial green light duration for phase clearance is 15 seconds.

[0096] Table 1 shows the typical minimum green values ​​for drivers with overdue driving licenses.

[0097]

[0098] Figure 3 This is a diagram showing the traffic flow and release status for a release phase and conflict waiting phases, combined with... Figure 3 This invention provides a detailed description of the time interval between the traffic flow cut-off points for adjusting the release phase provided by the present invention.

[0099] The phase 1 extension time is set to 5s, the initial cutoff workshop time interval is 5s, the time before the cutoff workshop time interval decreases after the conflict phase request is 14s, the minimum cutoff workshop time interval is 2s, the unit cutoff workshop time interval decrease value is 0.1s (execution interval is 100ms), the strategic detector queuing level is 1, the minimum green is 7s, and the maximum green is 30s.

[0100] When Phase 1 starts allowing traffic from 0s, a vehicle request occurs in conflicting Phase 2. Phase 1 begins timing its cutoff timer before the timeout decreases. After the minimum green timer for Phase 1 expires, the extended timer and the initial cutoff timeout timer begin counting down. At 11s, a vehicle request occurs in Phase 1. At this time, the initial cutoff timeout timer still has 1s remaining. Both the extended timer and the cutoff timeout timer are reset to 5s, and the phase continues to allow traffic. At 14s, the timer before the cutoff timeout decreases expires, and the cutoff timeout for Phase 1 begins to decrease, according to the cutoff timeout calculation formula:

[0101] g = MAX(L) conflict -L release ,0)

[0102] P v =MAX(P i -Δp*g*(f now -T begin ), P min )

[0103] Currently, the strategic detector in phase 1 is not holding back any vehicles, and the queue length level is 0. The queue length level in conflict phase 2 is 1, so the rate of decrease in the cutoff time interval between vehicles is 1, meaning the cutoff time interval between vehicles in phase 1 decreases by 1 per second. Therefore, at 15s, vehicle requests in phase 1 will reset the extended timer to 5s and the cutoff time interval timer to 4s. At 17s, vehicle requests in phase 1 will reset the extended timer to 5s and the cutoff time interval timer to 2s. At 20s, the cutoff time interval timer has expired, so vehicle requests in phase 1 will not reset the extended timer and the cutoff time interval timer. Therefore, phase 1 ends its release at 22s when the extended timer expires.

[0104] Figure 4 The diagram illustrates the relationship between the extended timer and the truncated time interval timer. Further explanation of this relationship reveals that when a vehicle release request for a phase exists while the truncated time interval timer is still active, both the extended and truncated time interval timers are initialized and their timing restarts. However, when the truncated time interval timer has expired, the vehicle release request does not initialize either the extended or truncated time interval timers; the truncated time interval timer remains in an inactive state. The phase release ends after the extended timer expires. This ensures that the phase operates at saturated traffic flow, improving green light utilization, and also guarantees the safe release of the last valid request vehicle at the truncated time.

[0105] Figure 5 This is a schematic diagram of a phase dynamic maximum green adjustment, combined with Figure 5 The present invention provides a detailed description of the optimization and adjustment of the maximum green phase provided by the present invention.

[0106] At the end of each cycle, the termination status of all phases is calculated. If a phase terminates due to a lack of requests causing extended time invalidation, it is an early termination output phase; if a phase terminates because the maximum green value reaches its limit, it is a maximum output phase. For example... Figure 5As shown in the diagram, at the end of the first release cycle of the scheme, phase 1 is the early termination output phase. At the end of the second cycle, phase 1 is the maximum output phase. Since the condition of ending in the same state for two consecutive cycles is not met, this phase will not be adjusted for maximum green at the beginning of the third cycle. Until the end of the third cycle, phase 1 is again the maximum output phase. At this point, the condition of ending in the same maximum output state for two consecutive cycles (the second and third cycles) is met, indicating that the release demand for phase 1 is high, and the current maximum green cannot meet the release demand for phase 1. Therefore, a set step size needs to be added to the current maximum green. At the end of the fourth cycle, phase 1 is still the maximum output phase, indicating... Even after increasing the step size, the maximum green still does not meet the release requirements of the current phase 1. So, the step size is increased by one more step until the end of the seventh cycle. At this point, the dynamic maximum green has been adjusted to the set dynamic maximum green upper limit constraint. At this time, the subsequent maximum output phase 1 always operates with the dynamic maximum green upper limit as the constraint and will not continue to increase the step size. As the traffic flow of phase 1 decreases, after the end of the eleventh cycle, the phase has terminated its output prematurely for two consecutive cycles, indicating that the current maximum green duration is excessive. The current maximum green is reduced by one step. After the end of the twelfth cycle, the phase still terminates its output prematurely, indicating that the current maximum green after reducing the step size is still excessive. The current maximum green is further reduced by one step.

[0107] For timing and resetting the phase maximum green, this embodiment will combine Figure 6 Please provide a detailed explanation. For example... Figure 6 As shown, when a phase begins to allow traffic, since there are no conflicting requests, the maximum green time for that phase is not timed. The maximum green timer only begins when other conflicting phases request traffic release during operation, and the phase's release is terminated after the maximum green timer expires. That is, when there are no serviceable release requests for conflicting phases, the operating phase can continue to allow traffic as long as the vehicle spacing is less than the time interval between traffic cutoff points. This maximum green timer method balances the timeliness and fairness of the allocation of time resources for each phase at the intersection. When there is no competing release demand, the current phase can continue to allow traffic; when there is competition, the maximum allowable release time for the current phase must be limited.

[0108] The inductive optimization control method based on the dynamic changes in traffic flow and vehicle-to-vehicle distance provided by this invention can eliminate the impact of changes in traffic flow and vehicle-to-vehicle distance by collecting traffic flow data and traffic status in real time, thereby improving the effective utilization rate of green light time and reducing delays.

[0109] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention without departing from its spirit and scope should be included within the protection scope of the present invention.

Claims

1. A sensing optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval, characterized in that, The method includes the following steps: Step 1: Based on the key waiting traffic flow data of the phase before the release, the remote strategic detector is used to calculate the phase's initial green light duration; Step 2: Based on the cumulative vehicle delay time and queue length of the conflicting phase, and the queue length of the current release phase, adjust the vehicle flow cut-off time interval of the release phase, and time the induction extension time and cut-off time interval of the timing phase respectively. Step 3: Based on the continuous release termination status of the phase in the cycle, optimize and adjust the maximum green of the phase before the release in the next cycle; Step 4: Based on whether there are any conflicting phase release requests that can be served in the current running phase, time and reset the maximum green of the phase.

2. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 1, characterized in that, The key waiting traffic flow data for the phase mentioned in step 1 before the green light is released is as follows: For a single-lane phase, all arriving vehicles from the end of the previous green light cycle to the start of the current green light cycle are the key waiting traffic flow data; for a multi-lane phase, the maximum number of arriving waiting vehicles in each lane is selected as the key waiting traffic flow data.

3. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 1, characterized in that, The step 1, which involves correcting the initial green light duration for phase clearance, specifically includes: The initial green light duration is dynamically adjusted based on the current critical waiting traffic flow data for each phase, and is subject to minimum and maximum initial green light constraints. The formula for calculating the initial green light duration is as follows: G v =MAX(MIN(t d +i*c,G maxv ),G min ) Among them, G maxv For the maximum initial green, t d The vehicle start-up delay time, where i is the increment step, D is the distance between the stop line and the downstream edge of the nearest far-end detector area, and L is the vehicle start-up delay time. v For the default vehicle length, G v G represents the initial green light interval for the phase, c represents the critical waiting traffic volume before the phase is released, and G represents the initial green light interval for the phase. min Minimum green constraint time for safety.

4. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 3, characterized in that, The increment of the unit is the time it takes for the vehicle to pass the stop line.

5. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 1, characterized in that, Step 2, adjusting the time interval between traffic flow cutoff points in the release phase, specifically includes: The formula for calculating the time interval between traffic flow cutoff points is as follows: g=MAX(L conflict -L release ,0) P v =MAX(P i -Δp*g*(T now -T begin ),P min ) Where g is the rate at which the time interval between traffic flow cutoff points decreases, and L conflict L represents the queue length level for conflict phases. release For the queue length level of the phase being released, P v To cut off the time interval between trains in a variable traffic flow, P i The initial cutoff time interval is T, where Δp is the unit cutoff time interval decrease value. now At the current time point, T begin P is the point in time when the accumulated time of conflict phase delay reaches a set value. min Minimum cutoff time interval constraint.

6. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 5, characterized in that, The induction extension time and truncation time of the timing phase mentioned in step 2 specifically include: The timing sensing extension time is used to extend the phase release, and the timing cutoff workshop time interval time is used to initialize the sensing extension timing. When a phase begins to release traffic, the set induction extension time is used as the upper limit of the initial traffic flow cutoff time. When the accumulated delay time of the conflicting phase reaches the preset value, the upper limit of the traffic flow cutoff time for the releasing phase is reduced according to the queue length of the releasing phase and the conflicting phase. When the timer for the running phase has not reached the upper limit of the cutoff time, it indicates that there is a release request, and the induction extension time and cutoff time timing are restarted. When the cutoff timer for the running phase reaches the upper limit, subsequent vehicle requests cannot initialize the induction extension time. The remaining induction extension time can ensure the safe release of the last valid request vehicle at the time of cutoff.

7. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 1, characterized in that, Step 3 describes optimizing the maximum green of a phase based on its continuous release termination status within a cycle, before releasing it in the next cycle. This specifically includes: statistically analyzing the phase termination status of each cycle; when a phase reaches its maximum green output twice consecutively, adding a dynamic step size to the running maximum green until the running maximum green exceeds the upper limit of the dynamic maximum green, then operating with the upper limit of the dynamic maximum green as a constraint; when a phase ends prematurely due to exceeding the cutoff time interval twice consecutively, subtracting a dynamic step size from the running maximum green until the running maximum green is less than the lower limit of the dynamic maximum green, then operating with the lower limit of the dynamic maximum green as a constraint; if a phase ends prematurely in one cycle and reaches its maximum green in the next cycle, or vice versa, then the running maximum green will not change.

8. The inductive optimization control method based on dynamic changes in traffic flow and inter-vehicle time interval as described in claim 1, characterized in that, Step 4, timing the maximum green phase, specifically includes: When there is no available release request for a conflicting phase, the operating phase will not time the maximum green timer. That is, the operating phase will continue to allow traffic to pass as long as the vehicle spacing is less than the time interval between traffic cutoff points. When there is an available release request for a conflicting phase, the operating phase will start timing the maximum green timer and will end the current operating phase's release once the maximum green timer reaches its limit. If the available release request for a conflicting phase disappears during the maximum green timer, the maximum green timer will be reset and maintained until the conflicting phase detects a request again and restarts timing.

9. A sensor-based optimization control system based on the dynamic changes in traffic flow and inter-vehicle time intervals, according to any one of claims 1 to 8, characterized in that: The system includes: The first module is used to collect key waiting traffic flow data of the phase before the phase is released based on the statistics of the remote strategic detector, and to correct the initial green light duration of the phase. The second module is used to adjust the vehicle flow cut-off time interval of the release phase based on the cumulative vehicle delay time, queue length, and queue length of the current release phase, and to time the induction extension time and cut-off time interval of the timing phase respectively. The third module is used to optimize and adjust the maximum green of the phase before the next release cycle based on the continuous release termination status of the phase in the cycle. The fourth module is used to time and reset the maximum green of the phase based on whether there is a conflict phase release request that can be served in the current running phase.

10. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1 to 8.

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