Pedestrian crossing signal control method based on radar detection

Abstract

The invention relates to a pedestrian crossing signal control method based on radar detection, and the method comprises the steps: S1, a first radar determines the number of effective waiting pedestrians according to the waiting time of the pedestrians in a roadside waiting region, and then determines the maximum waiting time, and the maximum waiting time is configured to be that the larger the number of the effective waiting pedestrians detected by the first radar in the roadside waiting region is, the smaller the number of the effective waiting pedestrians is; the maximum waiting time is shorter; s2, determining the turn-on time of the passing phase signal lamp according to the maximum waiting time; and S3, determining the traffic capacity Ci of the pedestrian crossing area, and adjusting the traffic duration t of the traffic phase signal lamp according to the number P of the effective waiting pedestrians and the traffic capacity Ci. According to the invention, pedestrian state detection is carried out on pedestrian crossing key areas such as a roadside waiting area and a crossing channel area, pedestrian crossing demands, behavior characteristics and characteristics of a pedestrian crossing area are comprehensively considered, pedestrian waiting duration and pedestrian crossing duration are intelligently and dynamically adjusted, pedestrian crossing passage delay is reduced, and pedestrian crossing efficiency is improved. And the overall passing efficiency and quality are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial intelligence, and particularly relates to a pedestrian crossing signal control method based on radar detection. Background Art

[0002] Unsignalized pedestrian crossing in cities is a weak link in urban traffic organization and is prone to traffic accidents. Even if pedestrians choose to cross the street at the crosswalk area, due to the insufficient safety awareness of traffic participants and the situation that motor vehicle drivers do not decelerate or stop to give way, accidents still cannot be avoided.

[0003] When the waiting time of pedestrians accumulates to a certain extent and they still need to wait, pedestrians often subconsciously approach the motor vehicle lane. When it exceeds the tolerance of pedestrians, pedestrians often choose to forcibly cross the gap between vehicles, creating potential accident hazards.

[0004] Pedestrian crossing signal control mainly realizes the control of pedestrian crossing traffic through technical means, and allocates the green light duration for pedestrian crossing, so as to ensure the traffic safety of pedestrians crossing the street. Regarding the pedestrian crossing detection and signal control methods, there are mainly: fixed-cycle control, pedestrian button method, video detection method, and thermal imaging method.

[0005] Fixed-cycle control: Set fixed green light durations for motor vehicles and pedestrians, and adjust them through the switching of timing plans at different time periods. The disadvantage is that the green light duration for pedestrian crossing is allocated regardless of whether there is a pedestrian demand, resulting in wasted green lights for pedestrians when there is no pedestrian demand.

[0006] Pedestrian button method: By setting a pedestrian button, pedestrians generate a crossing demand by pressing the button, and the road traffic signal controller (signal machine) allocates the green light duration for pedestrian crossing to ensure the safe passage of pedestrians; if there is no pedestrian demand, the green light duration for pedestrian crossing is not allocated. The first disadvantage is passive detection, which requires pedestrians to actively press the button, otherwise it will not take effect; the second disadvantage is that if pedestrians change their action decisions after pressing the button, such as crossing in other directions or crossing through the gap in the motor vehicle traffic flow, the road traffic signal controller (signal machine) will still allocate the green light duration for pedestrian crossing.

[0007] Video detection method: Actively detect pedestrians, and can detect the number of pedestrians, walking directions, etc., and allocate the green light duration for pedestrian crossing accordingly. The first disadvantage is that the detection accuracy will be greatly affected when the lens is dusty or the light changes, and the second disadvantage is that its usability is very low in bad weather such as rain, snow, fog, and strong wind.

[0008] Thermal imaging method: Actively detect pedestrian density and pedestrian occupancy rate, and allocate the green light duration for pedestrian crossing according to the detection results. The first disadvantage is that it is affected by the weather and the imaging effect is not good in heavy rain or high humidity environments, and the second disadvantage is that the equipment is expensive and the stability is poor, which limits its wide application. Summary of the Invention

[0009] An embodiment of the present invention provides a pedestrian crosswalk signal control method based on radar detection to solve the problems in the prior art that since only a fixed green light duration for pedestrians is reserved through algorithms, the demand for crossing time in different situations cannot be met, which easily causes waste or insufficiency of the green light duration for pedestrians to cross the road, and the resulting potential safety hazards for pedestrians crossing the road.

[0010] To achieve the above object, the embodiment of the present invention provides the following technical solutions:

[0011] A pedestrian crosswalk signal control method based on radar detection includes the following steps:

[0012] S1. The first radar determines the number of effective waiting pedestrians according to the waiting time of pedestrians in the roadside waiting area, and then determines the maximum waiting time according to the number of effective waiting pedestrians. The maximum waiting time is configured such that the more the number of effective waiting pedestrians detected by the first radar in the roadside waiting area, the shorter the maximum waiting time;

[0013] S2. Determine the opening time of the traffic phase signal lamp according to the maximum waiting time;

[0014] S3. Determine the traffic capacity Ci of the crosswalk area, and adjust the traffic duration t of the traffic phase signal lamp according to the number of effective waiting pedestrians P and the traffic capacity Ci. If the number of effective waiting pedestrians P in the roadside waiting area corresponding to the crosswalk area is less than or equal to the traffic capacity Ci of the crosswalk area, the traffic duration t of the traffic phase signal lamp only includes the reference duration tmin; if the number of effective waiting pedestrians P in the roadside waiting area corresponding to the crosswalk area is less than or equal to the traffic capacity Ci of the crosswalk area, the traffic duration t of the traffic phase signal lamp needs to be extended, that is, the time ti for pedestrians to enter the crosswalk area is added on the basis of the reference duration tmin, that is, t = ti + tmin.

[0015] Further, in S1, the method for determining the effective waiting pedestrians according to the waiting time of pedestrians in the roadside waiting area includes: the first radar starts effective judgment timing when detecting that a pedestrian enters the roadside waiting area, and the effective judgment timing is bound to the pedestrian. If the pedestrian is still in the roadside waiting area after the effective judgment timing ends, the system determines that the pedestrian is an effective waiting pedestrian; if the pedestrian leaves the roadside waiting area before the effective judgment timing ends, the effective judgment timing for the pedestrian is stopped and deleted.

[0016] Further, in S1, the number of effective waiting pedestrians is divided into 3 pedestrian waiting levels with a span, including:

[0017] Level 1, when the number of effective waiting pedestrians increases to 6 - 9 people, the maximum waiting time is relatively long (70 - 90 seconds);

[0018] Level 2: When the number of effective waiting pedestrians increases to 7 - 15, the maximum waiting time is reduced (65 - 80 seconds).

[0019] Level 3: When the number of effective waiting pedestrians increases to 8 - 20, the maximum waiting time is rapidly reduced (55 - 70 seconds).

[0020] Furthermore, in S1, the timing method of the maximum waiting time includes:

[0021] When the first radar detects the first effective waiting pedestrian in the roadside waiting area, the timing of the maximum waiting time for the roadside waiting area starts. For example, continuous timing of the waiting time starts from the appearance of the first effective waiting pedestrian, that is, the timing of the maximum waiting time; or, when the first radar detects the first pedestrian entering the roadside waiting area, the maximum waiting time timing starts. If the earliest arriving pedestrian is not an effective waiting pedestrian, the maximum waiting time timing starts continuous timing from the next pedestrian, and the loop is executed to ensure that the first effective waiting pedestrian appears within the maximum waiting time timing.

[0022] Furthermore, in S1, the maximum waiting time is dynamically adjusted according to the change in the number of effective waiting pedestrians.

[0023] Furthermore, in S2, the remaining waiting time is the maximum waiting time minus the actual waiting time. If the remaining waiting time ends normally during operation or the remaining waiting time is zero or negative after the maximum waiting time jumps, the traffic signal for the pedestrian crossing phase is activated to allow pedestrians to cross the road.

[0024] Furthermore, in S3, the traffic capacity Ci of the crosswalk area = round(Di / 2 / 0.9).

[0025] Furthermore, in S3, if the number P of effective waiting pedestrians in the roadside waiting area corresponding to the crosswalk area is less than or equal to the traffic capacity Ci of the crosswalk area, the passing duration t of the traffic signal for the pedestrian crossing phase only includes the reference duration tmin, and the reference duration is the minimum continuous duration; if the number P of effective waiting pedestrians in the roadside waiting area corresponding to the crosswalk area is less than or equal to the traffic capacity Ci of the crosswalk area, the passing duration t of the traffic signal for the pedestrian crossing phase needs to be extended, that is, on the basis of the reference duration tmin, the time ti for pedestrians to enter the crosswalk area is added, that is, t = ti + tmin.

[0026] Furthermore, in S3, when the traffic signal for the pedestrian crossing phase is activated, the delay judgment timing is simultaneously activated. If there are newly arrived pedestrians during the delay judgment timing, the passing duration t of the traffic signal for the pedestrian crossing phase is extended by an additional time.

[0027] The embodiments of the present invention have the following advantages:

[0028] The present invention adopts radar technology to detect the pedestrian status in key areas for pedestrians to cross the road, such as the roadside waiting area and the crosswalk passage area, dynamically detect the real-time road conditions and pedestrian status, comprehensively consider the pedestrian crossing needs, behavioral characteristics and the characteristics of the crosswalk area itself, formulate the working strategy of the road traffic signal controller (signal machine), intelligently and dynamically adjust the pedestrian waiting time and the pedestrian crossing time, ensure the traffic safety of pedestrians crossing the road, reduce the delay of pedestrians crossing the road, reduce the phenomenon of pedestrians running red lights in groups when crossing the road, strengthen the traffic safety guarantee for pedestrians crossing the road, and effectively improve the overall traffic efficiency and quality. Brief Description of the Drawings

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0030] The structures, ratios, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have any technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention.

[0031] Figure 1 It is a flowchart of a method for controlling pedestrian crossing signals based on radar detection provided by an embodiment of the present invention;

[0032] Figure 2 It is a working schematic diagram of the first radar in a method for controlling pedestrian crossing signals based on radar detection provided by an embodiment of the present invention;

[0033] Figure 3 It is a working schematic diagram of the second radar in a method for controlling pedestrian crossing signals based on radar detection provided by an embodiment of the present invention. Detailed Embodiments

[0034] The following specific embodiments illustrate the implementation manners of the present invention. Those familiar with this technology can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0035] As Figure 1 shown, a pedestrian crosswalk signal control method based on radar detection includes the following steps:

[0036] S1. The first radar determines the number of valid waiting pedestrians according to the waiting time of pedestrians in the roadside waiting area, and then determines the maximum waiting time according to the number of valid waiting pedestrians.

[0037] 1-1. The method for the first radar in this technology to track pedestrians.

[0038] As Figure 2 shown, in this technology, a first radar needs to be set up to detect the situation of pedestrians in the roadside waiting area. For example, the first radar is set on the lamp post on the roadside, and the first radar overlooks the roadside waiting area, and the field of view of the first radar includes the entire roadside waiting area.

[0039] According to the requirements of the pedestrian detection area in the roadside waiting area, the detection angle range of the first radar is 20° - 35°, and the height range is 3.3 meters - 4.0 meters. In this embodiment, the model of the first radar can be CZ100. Calibrate the static initial environment of the detection area, collect marker data. The markers are defined as static objects such as guardrails, isolation fences, and vehicle-blocking roadblocks with unchanged size and position. The marker data is defined as the fixed grid data occupied by the markers, and calibrate the radar device to form the static grid data of the first radar detection area.

[0040] Different from the static initial environment, pedestrians (targets) entering the detection area later will be detected with grid traces in the moving area. The first radar will continuously perform processes such as target relay, multi-target duplicate removal, and output of the absolute coordinates of the target area grid, so as to mark, count, and calculate the waiting time of pedestrians (targets).

[0041] After pedestrians (targets) enter the detection area, the first radar will detect multiple reflection points in the actual physical situation of the target and generate a set of corresponding measurement results, including information such as radial distance, azimuth angle, and radial velocity.

[0042] Target relay refers to classifying reflection points with specific attributes such as position, speed, contour, and point density, associating multiple reflection points and assigning them to a pedestrian (target) set, and performing statistical modeling for each pedestrian.

[0043] Multi-target duplicate removal means that there will be occlusion and obstruction effects between multiple pedestrians (targets). These reflection points are divided into sets according to the proximity of their specific attributes, and each set becomes a candidate for the assignment process. This set must meet multiple threshold checks before it is considered a new pedestrian (target) set and statistical modeling is performed.

[0044] The absolute coordinate output of the target area grid updates the pedestrian (target) based on the statistical modeling results of the previous two steps and outputs the algorithm results for a series of associated detection values.

[0045] 1-2. A method for determining effective waiting pedestrians based on the waiting time of pedestrians in the roadside waiting area.

[0046] When the first radar detects that a pedestrian enters the roadside waiting area, the effective judgment timing starts. This effective judgment timing is bundled with the corresponding pedestrian and is used to determine whether the pedestrian is an effective waiting pedestrian. If the pedestrian is still in the roadside waiting area after the end of the effective judgment timing, the system determines that this pedestrian is an effective waiting pedestrian; if the pedestrian leaves the roadside waiting area before the end of the effective judgment timing, the effective judgment timing for this pedestrian is stopped and deleted.

[0047] 1-3. Determining the maximum waiting time based on the number of effective waiting pedestrians.

[0048] The maximum waiting time is the overall waiting time of the roadside waiting area and is used to record the continuous waiting time of all pedestrians in this roadside waiting area. When there are too many pedestrians gathered, herd mentality will occur, resulting in pedestrians ignoring the pedestrian crossing signal and forcibly crossing the road, which will disrupt traffic. To solve this problem in this technology, the maximum waiting time is configured such that the more the number of effective waiting pedestrians detected by the first radar in the roadside waiting area, the shorter the maximum waiting time.

[0049] Affected by factors such as the intersecting road grade (road width, number of lanes, motor vehicle flow size), the situation at the pedestrian crossing (such as whether it is near a school, hospital, large commercial place, etc.), the subjective choice behavior of pedestrians (judgment of the safe crossing gap between vehicles), and local traffic management measures (such as: the presence or absence of traffic wardens), the maximum acceptable waiting time for pedestrians is not unique and usually takes values within a range according to the actual road traffic conditions. Relevant investigation and research show that the maximum acceptable waiting time for pedestrians is usually 70 seconds. When the traffic flow is large (without a safe crossing gap between vehicles), the maximum acceptable waiting time for pedestrians should not be greater than 90 seconds. If this limit is exceeded, signal control schemes such as adding pedestrian safety islands and secondary pedestrian crossings or overpasses and underpasses for pedestrians can be considered. However, as the waiting time increases and exceeds a certain level, when there are too many waiting pedestrians, herd mentality will occur, resulting in pedestrians ignoring the pedestrian crossing signal and forcibly crossing the motor vehicle flow, and the controllability of the pedestrian traffic flow becomes poor. At this time, it is necessary to reduce the maximum waiting time to release the pedestrian traffic flow as soon as possible. Therefore, in one implementation of this technology, to simplify data processing, the number of effective waiting pedestrians is divided into multiple pedestrian waiting levels with a span, and a maximum waiting time is set for each level of the pedestrian waiting level. The higher the pedestrian waiting level, the shorter the set maximum waiting time. Specifically, the number of effective waiting pedestrians is divided into the following three levels:

[0050] Level 1: When the number of effective waiting pedestrians increases from 0 to 6 - 9 (preset value, adjustable according to the situation), the maximum waiting time acceptable to pedestrians is relatively long.

[0051] Level 2: When the number of effective waiting pedestrians increases to 7 - 15 (preset value, adjustable according to the situation), the maximum waiting time decreases.

[0052] Level 3: When the number of effective waiting pedestrians increases to 8 - 20 (preset value, adjustable according to the situation), the maximum waiting time decreases rapidly.

[0053] It should be emphasized that dividing the number of effective waiting pedestrians into the following three levels in this embodiment is only an example, and it is not limited to only three levels. As long as the technical solution that "divides the effective waiting pedestrians into multiple levels and the maximum waiting time changes in the opposite direction according to the number of effective waiting pedestrians" is within the scope of protection of this technology.

[0054] Furthermore, the timing method of the maximum waiting time includes:

[0055] When the system determines that the first effective waiting pedestrian appears in the roadside waiting area, start timing the maximum waiting time for this roadside waiting area. For example, start continuously timing the waiting time from the appearance of the first effective waiting pedestrian, that is, timing the maximum waiting time.

[0056] Or, when the first radar detects the first pedestrian entering the roadside waiting area, start timing the maximum waiting time. If the earliest arriving pedestrian is not an effective waiting pedestrian, then the maximum waiting time starts to be continuously timed from the next pedestrian, and loop to ensure that the first effective waiting pedestrian appears within the maximum waiting time timing.

[0057] Furthermore, dynamically adjust the maximum waiting time according to the change in the number of effective waiting pedestrians.

[0058] The first radar continuously and real - time detects the number of effective waiting pedestrians in the roadside waiting area. When the passing - phase signal light (green light) is activated, pedestrians will cross the street by themselves and leave the detection area, and at this time, the first radar does not detect.

[0059] When the stop - phase signal light (red light) is activated, the first radar starts to detect. If the first radar detects that a pedestrian enters the roadside waiting area or the first effective waiting pedestrian appears in the roadside waiting area, start timing the maximum waiting time, and at this time, the maximum waiting time is the maximum value.

[0060] If the number of effective waiting pedestrians detected by the first radar meets the number condition of Level 1, the maximum waiting time becomes the maximum waiting time T1 of Level 1, then the remaining waiting time = T1 - the actual waiting time of the first effective waiting pedestrian;

[0061] If the number of valid waiting pedestrians detected by the first radar meets the number condition of level two, the maximum waiting time becomes the maximum waiting time T2 of level two, then the remaining waiting time = T2 - the actual waiting time of the first valid waiting pedestrian;

[0062] If the number of valid waiting pedestrians detected by the first radar meets the number condition of level three, the maximum waiting time becomes the maximum waiting time T3 of level three, then the remaining waiting time = T3 - the actual waiting time of the first valid waiting pedestrian.

[0063] S2. Determine the opening time of the traffic phase signal lamp according to the maximum waiting time.

[0064] The maximum waiting time minus the actual waiting time is the remaining waiting time, and the remaining waiting time runs in a countdown. Specifically, if the remaining waiting time has not ended during normal operation (positive value) or the remaining waiting time is positive after the maximum waiting time jumps, the traffic phase signal lamp waits to start.

[0065] If the remaining waiting time ends during normal operation (is zero) or the remaining waiting time ends (is zero or negative) after the maximum waiting time jumps, the traffic phase signal lamp starts to release pedestrians to cross the street.

[0066] S3. Adjust the passing duration (such as the green light duration) of the traffic phase signal lamp according to the number of valid waiting pedestrians P.

[0067] 3-1. Determination method of the passing capacity Ci of the crosswalk area.

[0068] Determine the passing capacity Ci of each row of queues in the crosswalk area according to the width Di of the crosswalk area. Since the crosswalk area has two-way traffic and it is necessary to keep the width of the pedestrian belt above 0.9 meters to ensure that pedestrians do not collide with each other when walking and do not significantly affect the walking speed, the passing capacity Ci of the crosswalk area = round(Di / 2 / 0.9). For example, Figure 2-3 as shown, the passing capacity C4 of the 4-meter-wide crosswalk area = round(4 / 2 / 0.9) = 2 columns. The passing capacity Ci of each row of queues in the crosswalk area is a fixed attribute of this crosswalk area.

[0069] 3-2. Adjust the passing duration of the traffic phase signal lamp according to the number of valid waiting pedestrians P and the passing capacity Ci.

[0070] Compare the number of valid waiting pedestrians P in the roadside waiting area corresponding to the current crosswalk area with the passing capacity Ci of each row of queues in the current crosswalk area to determine the passing duration of the traffic phase signal lamp. The specific comparison method is as follows:

[0071] If the effective number of waiting pedestrians P in the roadside waiting area corresponding to the crosswalk area is less than or equal to the traffic capacity Ci of the crosswalk area, the passing duration t of the passing phase signal light only includes the reference duration tmin, and the reference duration is the minimum continuous duration. For example, the green light continuous duration is the minimum continuous duration. During the reference duration tmin, the passing phase signal light flashes, which means that pedestrians are not allowed to enter the crosswalk area, and pedestrians who have already entered can continue to pass. The reference duration tmin = the length of the crosswalk area ÷ the average pedestrian speed (the average pedestrian speed is usually taken as 1.0 m / s). If the slope exceeds 3%, for every additional 10%, the pedestrian speed decreases by 0.1 m / s. For example, if the length of the crosswalk area is 25 meters and the slope is 3%, then tmin = 25 seconds.

[0072] If the effective number of waiting pedestrians P in the roadside waiting area corresponding to the crosswalk area is less than or equal to the traffic capacity Ci of the crosswalk area, the passing duration t of the passing phase signal light needs to be extended, that is, an additional time ti for pedestrians to enter the crosswalk area is added on the basis of the reference duration tmin, that is, t = ti + tmin, and the time ti for pedestrians waiting to cross the street to enter the crosswalk area = ((P - Ci) / Ci) * 0.3. Specifically, the passing duration t of the passing phase signal light includes the sum of the time ti for pedestrians waiting to cross the street to enter the crosswalk area and the minimum passing duration tmin, that is, t = ti + tmin. That is, during the time ti, the passing phase signal light is green, and pedestrians can enter the crosswalk area and pass; during the time tmin, the passing phase signal light flashes green, and pedestrians are not allowed to enter the crosswalk area, and pedestrians who have already entered can continue to pass.

[0073] Further, a situation of extending the passing phase signal light.

[0074] When the passing phase signal light is started, the waiting pedestrians will cross the street through the crosswalk area in turn. The passing duration t of the passing phase signal light will ensure that the pedestrians in the roadside waiting area can safely pass through the crosswalk area. After all the waiting pedestrians enter the crosswalk area, the delay determination timing is started. In this technology, the delay determination timing is 1 - 4 seconds. If there are newly arrived pedestrians during the delay determination timing, the passing duration t of the passing phase signal light will be extended by an additional time. In this technology, the additional time is usually 1 - 4 seconds, which is used to enable the newly entered pedestrians to safely pass. Specifically, when the passing phase signal light is started, the delay determination timing will be started. During the delay determination timing, if the first radar detects that there are newly entered pedestrians in the roadside waiting area, and the pedestrian walks out of the roadside waiting area from one side of the crosswalk area, and the second radar detects the pedestrian in the crosswalk area based on target relay, the passing duration t of the passing phase signal light will be extended by an additional time.

[0075] During the passage time t of the passage-phase signal light, the delay determination timing can be repeated multiple times until the passage time t of the extended additional time ends, that is, when the maximum passage time t is reached, the delay determination timing is no longer performed, and the pedestrians arriving later cannot enter the crosswalk area and need to wait for the next cycle to pass.

[0076] Furthermore, it is a situation of extending the pedestrian clearance time (all-red).

[0077] If, after the passage time of the passage-phase signal light ends, the second radar detects that there are still pedestrians passing on the crosswalk area, then an additional pedestrian clearance time (all-red) is added. The pedestrian clearance time refers to the situation where, after the pedestrian phase ends (red light), the motor vehicle phase also remains red, that is, no motor vehicles are released to protect the pedestrians on the crosswalk area. The pedestrian clearance time can be cycled multiple times until the second radar detects that there are no pedestrians on the crosswalk area. After the second radar detects that there are no pedestrians on the crosswalk area and the last pedestrian clearance time ends, the motor vehicle passage-phase signal light will be activated to release the motor vehicles to pass.

[0078] During the process of starting the pedestrian clearance time, the effect of urging pedestrians to quickly pass through the crosswalk area can be achieved by the flashing, color change of the signal light or the playing of a reminder audio, such as the red signal light switching to a flashing red signal light, or playing voices such as "The passage has ended, please quickly leave the crosswalk area".

[0079] Such as Figure 3 As shown in the figure, the second radar can be set on the lamp posts on both sides of the crosswalk area and overlook the crosswalk area obliquely. The irradiation range of the second radar includes the entire crosswalk area. If the second radar detects that there are moving pedestrians (targets) on the crosswalk area, it is determined that there are still pedestrians who have not passed, and the pedestrian clearance time (all-red) is extended to protect the pedestrians; if not, it is determined that the crosswalk is clear and the motor vehicle passage-phase signal light is started to be released.

[0080] Furthermore, in step S2, it is also necessary to determine whether the signal phase of the pedestrian crossing signal light belongs to a coordinated signal phase with other adjacent intersections. If the maximum waiting time arrives and it is in the coordinated signal phase at this time, it is necessary to wait for the release signal of the coordinated signal phase before switching the passage-phase signal light to the passage state to release the pedestrians to cross the street. The coordinated control refers to the coordinated operation between multiple consecutive traffic intersections and pedestrian crossings on the road section, that is, when the motor vehicles released by the green lights in the coordinated signal phases of the upstream and downstream intersections reach the corresponding intersections and road sections, they can pass through while the green lights are on. If the signal phase of the pedestrian crossing signal light is coordinated with other adjacent intersections, the corresponding coordinated operation relationship needs to be ensured to meet the requirements of the coordinated phase difference.

[0081] Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A pedestrian crossing signal control method based on radar detection, characterized in that: The following steps are involved: S1, the first radar determines the number of effective waiting pedestrians according to the waiting time of pedestrians in the roadside waiting area, and then determines the maximum waiting time according to the number of effective waiting pedestrians, wherein the maximum waiting time is configured such that the more the number of effective waiting pedestrians detected by the first radar in the roadside waiting area is, the shorter the maximum waiting time is; S2. Determine the timing of turning on the traffic phase signal lamp according to the maximum waiting time; S3. Determine the capacity Ci of the pedestrian crossing area, and adjust the passage time t of the passage phase signal light according to the effective number of waiting pedestrians P and the passage capacity Ci. If the effective number of waiting pedestrians P in the roadside waiting area corresponding to the pedestrian crossing area is lower than or equal to the passage capacity Ci of the pedestrian crossing area, the passage time t of the passage phase signal light only includes the reference time tmin; if the effective number of waiting pedestrians P in the roadside waiting area corresponding to the pedestrian crossing area is lower than or equal to the passage capacity Ci of the pedestrian crossing area, the passage time t of the passage phase signal light needs to be extended, that is, the time ti for pedestrians to enter the pedestrian crossing area is increased on the basis of the reference time tmin, that is, t=ti+tmin.

2. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S1, the method for determining the effective waiting pedestrian based on the waiting time of the pedestrian in the roadside waiting area includes: the first radar detects that the pedestrian enters the roadside waiting area and starts the effective judgment timing, and the effective judgment timing is bound to the pedestrian. If the pedestrian is still in the roadside waiting area after the effective judgment timing ends, the system determines that the pedestrian is a valid waiting pedestrian; if the pedestrian leaves the roadside waiting area before the effective judgment timing ends, the effective judgment timing for the pedestrian is stopped and deleted.

3. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S1, the number of effective waiting pedestrians is divided into three pedestrian waiting levels with spans, including: Level 1: When the number of effective waiting pedestrians increases to 6 to 9, the maximum waiting time is longer (70 to 90 seconds); Level 2: When the number of effective waiting pedestrians increases to 7 to 15, the maximum waiting time decreases (65 to 80 seconds); At level three, when the number of effective waiting pedestrians increases to 8 to 20, the maximum waiting time decreases rapidly (55 to 70 seconds).

4. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S1, the timing method of the maximum waiting time includes: When the first radar detects the first valid waiting pedestrian in the roadside waiting area, the maximum waiting time of the roadside waiting area is started to be counted, such as the waiting time is continuously counted from the first valid waiting pedestrian appears, that is, the maximum waiting time is counted; Alternatively, when the first radar detects the first pedestrian entering the roadside waiting area, the maximum waiting time starts to count. If the earliest arriving pedestrian is not a valid waiting pedestrian, the maximum waiting time starts to count continuously from the next pedestrian, and the cycle is executed to ensure that the first valid waiting pedestrian appears within the maximum waiting time.

5. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S1, the maximum waiting time is dynamically adjusted according to the change in the number of effective waiting pedestrians.

6. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S2, the maximum waiting time minus the actual waiting time is the remaining waiting time. If the remaining waiting time ends normally or the remaining waiting time is zero or negative after the maximum waiting time jumps, the traffic phase signal light is started to allow pedestrians to cross the street.

7. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S3, the traffic capacity of the pedestrian crossing area Ci=round(Di / 2 / 0.9).

8. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S3, if the number of effective waiting pedestrians P in the roadside waiting area corresponding to the pedestrian crossing area is less than or equal to the traffic capacity Ci of the pedestrian crossing area, the traffic duration t of the traffic phase signal light only includes the reference duration tmin, and the reference duration is the minimum continuation duration; If the number of effective waiting pedestrians P in the roadside waiting area corresponding to the crosswalk area is lower than or equal to the traffic capacity Ci of the crosswalk area, the passage time t of the traffic phase signal light needs to be extended, that is, the time ti for pedestrians to enter the crosswalk area is increased on the basis of the benchmark time tmin, that is, t=ti+tmin.

9. The method for controlling pedestrian crossing signals based on radar detection according to claim 1, characterized in that: In S3, when the traffic phase signal light is activated, the delay determination timing is simultaneously activated. If a new pedestrian arrives during the delay determination timing, the traffic duration t of the traffic phase signal light is extended by an additional time.

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