1. A pedestrian traffic behavior distinguishing method in a subway station based on video data is characterized by comprising the following steps: the method comprises the steps of tracking positions of all pedestrians in video data in real time, and judging the individual behaviors, the interactive behaviors and the obstacle avoidance behaviors of the pedestrians according to the space and the passing space between the pedestrians or between the pedestrians and the obstacles, so that the traffic evacuation in the subway station is effectively guided.

2. The method for discriminating pedestrian traffic behavior in a subway station based on video data as claimed in claim 1, wherein: and calculating the passing space between the pedestrian i and the pedestrian j closest to the pedestrian i one by one according to the position information of each pedestrian at a certain moment t, if the passing space is larger than the minimum space allowing the pedestrian to walk, judging that the pedestrian i and the pedestrian j both have single behaviors, and otherwise, judging that the pedestrian i and the pedestrian j have interactive behaviors.

3. The method for discriminating pedestrian traffic behavior in a subway station based on video data as claimed in claim 2, wherein: the interactive behaviors include a follow-up behavior, an override behavior, an avoidance behavior, and an intervening behavior,

according to the included angle of the pedestrian i and the pedestrian j in the walking directionJudging whether the pedestrian i and the pedestrian j walk in the same direction or not, if so, further calculating the distance between the pedestrian i and the pedestrian j in the direction perpendicular to the walking direction, and judging whether a following behavior, an overrunning behavior or an inserting behavior occurs between the pedestrian i and the pedestrian j according to the change trend of the distance along with the time;

if the directions are not the same, the two pedestrians walk in opposite directions, and an avoidance behavior occurs between the pedestrian i and the pedestrian j.

4. The method for discriminating pedestrian traffic behavior in a subway station based on video data as claimed in claim 3, wherein: if the included angle isJudging that the pedestrian i and the pedestrian j walk in the same direction, and further calculating the distance D between the pedestrian i and the pedestrian j within three seconds after a certain time t_HThe transverse distance between the two is recorded as D in the first second after a certain time t_{H plays}And after the third second the transverse distance between the two is D_{H terminal}If | D_{H plays}-D_{H terminal}If | is greater than 0, the insertion behavior is determined, and if | D_{H plays}-D_{H terminal}|<0, judging as overtaking behavior, if | D_{H plays}-D_{H terminal}If 0, judging the following behavior;

if the included angle isJudging that the pedestrian i and the pedestrian j do not walk in the same direction and generating an avoidance behavior;

wherein, theta_ij＝180-α_it+α_jt，

(x_it,y_it),(x_jt,y_jt) The coordinate system of the pedestrian i and the pedestrian j is Y-axis in the walking direction and X-axis in the direction perpendicular to the walking direction.

5. The method for discriminating pedestrian traffic behavior in a subway station based on video data as claimed in claim 2, wherein: the individual behaviors including walking behavior, loitering behavior, and staying behavior,

calculating the average walking speed v and the walking distance S of the pedestrians i and j within three seconds after a certain time t and the distance d between the starting point and the end point of walking,

1) if the average walking speedIf the speed is lower than the normal speed of normal walking of people, judging that the pedestrians i and j stop, and if not, executing the step 2);

2) if the distance d is less than S/2 and d < ═ 1.5 meters, determining that the pedestrian i and the pedestrian j have loitering behaviors, and if not, executing the step 3);

3) and judging that the pedestrians i and j have normal walking behaviors.

6. The method for discriminating pedestrian traffic behavior in a subway station based on video data as claimed in claim 1, wherein: the obstacle avoidance behaviors comprise a retreating behavior and a lane changing behavior, the position of an obstacle which can be positioned on a walking channel by a fixing device in the subway station is calibrated in advance, an obstacle influence area is set, and the obstacle avoidance behavior comprises a retreating behavior and a lane changing behavior according to the position of each pedestrian at a certain moment tInformation (x)_it,y_it) The coordinate system of the pedestrian detection device takes the walking direction of the pedestrian as an axis Y and the direction vertical to the walking direction as an axis X, whether the pedestrian enters the obstacle influence area is judged, and if the pedestrian enters the obstacle influence area, the ordinate delta Y<And 0, judging that the pedestrian retreats, otherwise, judging that the lane changing behavior occurs.

Background

When the subway station implements passenger flow control, pedestrians in the station become managed objects. When a subway station is in a condition of high-density crowd, if abnormal traffic behaviors occur to pedestrian individuals, such as improper detention, wandering or retrograde motion near a gate, unstable states among the crowd can be caused, the traffic capacity is reduced, and even serious safety accidents such as trampling can be caused. Therefore, if a method for judging pedestrian traffic behaviors under different facility scenes and different crowd density conditions of the subway station can be found, a basis can be provided for facility safety design, passenger flow safety management and the like of the subway station, and therefore whether the type of the pedestrian traffic behavior can be accurately judged is important.

At present, experts and scholars at home and abroad carry out a great deal of research on pedestrian traffic flow characteristic parameters, mainly aim at the behavior mode of people, and have less research on individual traffic behavior characteristics and parameters, the research mainly identifies the pedestrian behaviors in a station based on the characteristics of human skeleton information, such as falling, bending and the like, and determines the behavior types by establishing a human skeleton model.

Disclosure of Invention

The invention provides a method for distinguishing pedestrian traffic behaviors in a subway station based on video data, and solves the problems of poor effectiveness, low accuracy, time and labor waste and the like of the conventional method for calculating the walking time.

The invention can be realized by the following technical scheme:

a method for judging pedestrian traffic behaviors in a subway station based on video data is used for tracking positions of all pedestrians in the video data in real time, judging the individual behaviors, the interactive behaviors and the obstacle avoidance behaviors of the pedestrians according to the space and the passing space between the pedestrians or between the pedestrians and an obstacle, and accordingly effectively guiding traffic evacuation in the subway station.

Further, according to the position information of each pedestrian at a certain time t, the passing space between the pedestrian i and the pedestrian j closest to the pedestrian i is calculated one by one, if the passing space is larger than the minimum space allowing the pedestrian to walk, the pedestrian i and the pedestrian j are judged to have single behaviors, and if not, the pedestrian i and the pedestrian j are judged to have interaction behaviors.

Further, the interactive behavior includes a following behavior, an overriding behavior, an avoiding behavior, and an intervening behavior,

according to the included angle of the pedestrian i and the pedestrian j in the walking directionJudging whether the pedestrian i and the pedestrian j walk in the same direction or not, if so, further calculating the distance between the pedestrian i and the pedestrian j in the direction perpendicular to the walking direction, and judging whether a following behavior, an overrunning behavior or an inserting behavior occurs between the pedestrian i and the pedestrian j according to the change trend of the distance along with the time;

if the directions are not the same, the two pedestrians walk in opposite directions, and an avoidance behavior occurs between the pedestrian i and the pedestrian j.

Further, if the included angleJudging that the pedestrian i and the pedestrian j walk in the same direction, and further calculating the distance D between the pedestrian i and the pedestrian j within three seconds after a certain time t_HThe transverse distance between the two is recorded as D in the first second after a certain time t_{H plays}And after the third second the transverse distance between the two is D_{H terminal}If | D_{H plays}-D_{H terminal}If | is greater than 0, the insertion behavior is determined, and if | D_{H plays}-D_{H terminal}|<0, judging as overtaking behavior, if | D_{Get up}-D_{H terminal}If 0, judging the following behavior;

if the included angle isJudging that the pedestrian i and the pedestrian j do not walk in the same direction and generating an avoidance behavior;

wherein the content of the first and second substances,

(x_it,y_it),(x_jt,y_jt) Respectively representing the position information of the pedestrian i and the pedestrian j at a certain time tThe coordinate system of the pedestrian-oriented walking vehicle takes the walking direction of the pedestrian as an axis Y, and the direction vertical to the walking direction as an axis X.

Further, the individual behaviors include walking behavior, loitering behavior, and staying behavior,

calculating the average walking speed v and the walking distance S of the pedestrians i and j within three seconds after a certain time t and the distance d between the starting point and the end point of walking,

1) if the average walking speedIf the speed is lower than the normal speed of normal walking of people, judging that the pedestrians i and j stop, and if not, executing the step 2);

2) if the distance d is less than S/2 and d < ═ 1.5 meters, determining that the pedestrian i and the pedestrian j have loitering behaviors, and if not, executing the step 3);

3) and judging that the pedestrians i and j have normal walking behaviors.

Furthermore, the obstacle avoidance behaviors comprise a retreating behavior and a lane changing behavior, the position of an obstacle which can be positioned on a walking channel by a fixing device in the subway station is calibrated in advance, an obstacle influence area is set, and the obstacle avoidance behavior comprises a retreating behavior and a lane changing behavior, and according to the position information (x) of each pedestrian at a certain moment t_it,y_it) The coordinate system of the pedestrian detection device takes the walking direction of the pedestrian as an axis Y and the direction vertical to the walking direction as an axis X, whether the pedestrian enters the obstacle influence area is judged, and if the pedestrian enters the obstacle influence area, the ordinate delta Y<And 0, judging that the pedestrian retreats, otherwise, judging that the lane changing behavior occurs.

The beneficial technical effects of the invention are as follows:

the individual behaviors and the interactive behaviors are distinguished according to the passing space R between pedestrians, and then the included angle of the pedestrians in the walking direction is usedAnd a transverse spacing D_HThe interactive behaviors are specifically divided, and then the individual behaviors are specifically divided according to the average walking speed, the walking distance S and the distance dAnd finally, according to the position information of the obstacle influence area and the pedestrians, the obstacle avoidance behaviors are specifically divided, so that the detailed identification of the traffic behaviors of the pedestrians in the subway station is completed, a data basis is provided for platform workers to relieve peak congestion, parameter bases are provided for analyzing the traffic characteristics of the passengers in the station in the peak period, simulating and predicting the space-time distribution of the passengers in the station, optimizing a subway station passenger transportation organization scheme, starting a station passenger flow plan and the like, and the method has important effects on improving the management level of the subway station passenger flow and guaranteeing the trip safety of the passengers.

Drawings

FIG. 1 is a schematic overview of the process of the present invention;

FIG. 2 is a schematic diagram of the detailed classification of pedestrian traffic behavior of the present invention;

FIG. 3 is a schematic diagram of the decision flow of the monomer behavior and the interaction behavior of the present invention;

FIG. 4 shows the angle θ between the pedestrian i and the pedestrian j in the walking direction_ijA schematic diagram;

FIG. 5 is a transverse separation D of a pedestrian i and a pedestrian j of the present invention_HSchematic representation.

FIG. 6 is a first embodiment of the traffic behavior determination method according to the present invention;

FIG. 7 is a second embodiment of the traffic behavior determination method according to the present invention;

FIG. 8 is a schematic diagram illustrating the verification comparison of the interactive behavior discrimination using the discrimination method of the present invention;

fig. 9 is a schematic diagram illustrating verification comparison of the obstacle avoidance behavior determination by the determination method of the present invention.

Detailed Description

The following detailed description of the preferred embodiments will be made with reference to the accompanying drawings.

As shown in fig. 1, the invention provides a method for distinguishing pedestrian traffic behaviors in a subway station based on video data, which distinguishes a series of behaviors occurring in the station by using traffic behavior characteristic parameters of pedestrians, such as position coordinates, speed, walking angles and the like, and can obtain parameter differences of different behaviors of different individuals or heterogeneous groups by distinguishing the specific behaviors of pedestrians, so that the method has important significance for analyzing different safety states of groups of people under high-density conditions in the subway station and researching a dredging facility safety design scheme adapted to the safety states. The method comprises the following specific steps:

firstly, obtaining the action track of a selected target by video data of a subway station through a motion track extraction algorithm, thereby obtaining the coordinate position information of the target at each moment.

The method comprises the steps of detecting moving targets such as pedestrians by utilizing video data of the subway station through an interframe difference method, and then obtaining target moving tracks through a moving track extraction algorithm based on moving target mass center position calculation, so that coordinate position information of the targets at each moment is obtained.

(1) For the extraction of the pedestrian motion trail, the existing software technology is used for processing in the actual operation. First, the video data to be analyzed is imported into software, such as Tracker, which is a free video analysis and modeling tool framework based on Open Source Physics (OSP) Java, with functions including target tracking and position, velocity and acceleration overlay and graphics, special effect filters for spectral and spectral analysis, multiple reference frames, calibration points, line profile interferograms, and dynamic particle models. The Tracker software tracks the motion trail of a research object by analyzing a physical experiment video, reveals physical laws by a simple and efficient data analysis means, and allows a user to establish a dynamic or kinematic model for simulation experiments. The Tracker software can be widely applied to physical demonstration experiment teaching and student extracurricular research learning, and is beneficial to enriching physical course resources, breaking through teaching difficulty and improving teaching quality.

In the video containing the fixed facilities, a central point of the fixed facilities and a coordinate point occupying the range, such as a gate, a railing and the like, can be labeled in advance, a coordinate system can be established by taking the walking direction of a pedestrian as a y-axis and taking the direction perpendicular to the walking direction as an x-axis, and an origin can be set as a coordinate origin by taking the central point of the fixed facilities such as the gate or the central point of a group of gates; if there is no fixed facility, such as a tunnel, the origin of coordinates can be arbitrarily chosen.

(2) The subject to be analyzed is then selected, either as a single subject or as multiple subjects for calibration, and the calibration point may be selected from the top of the head, shoulders, or some other point on the body, requiring that the calibration points be uniform for all subjects. In the actual operation, the head of the pedestrian is selected as the index point to track the motion trail, so that the situation of motion trail overlapping does not occur, the motion trail graph of the pedestrian in a section of video can be obtained, and the position coordinate parameters of all the pedestrians in each frame of image are obtained.

Secondly, dividing the traffic behaviors of pedestrians in the subway station into three major classes of single behaviors, interactive behaviors and obstacle avoidance behaviors according to the individual action, the coupling action between individuals and barriers and the coupling action between individuals and barriers, and subdividing the three classes of behaviors, wherein the single behaviors are divided into walking behaviors, wandering behaviors and staying behaviors; the interactive behaviors are divided into following behaviors, exceeding behaviors, avoiding behaviors and inserting behaviors; the obstacle avoidance behavior is divided into a lane change behavior and a retreat behavior, as shown in fig. 2, the specific determination method is as follows:

step one, distinguishing a single behavior and an interactive behavior according to a traffic space R between pedestrians, as shown in FIG. 3;

according to the obtained moving target track, position coordinate data of all pedestrians at different moments in the video can be obtained, and therefore the distance and the passing space between every two pedestrians can be calculated. The coordinates of the pedestrian i and the pedestrian j at the moment of t are respectively (x)_it,y_it)，(x_jt,y_jt) Then the distance d between the pedestrian i and the pedestrian j can be calculated according to the formula (1)_ij。

The passage space R between the pedestrian i and the pedestrian j is calculated according to the formula (2):

the pedestrian with the smallest passing space R, namely the pedestrian with the closest distance, such as the pedestrian j, is found, and the pedestrian i and the pedestrian j can be judged to be single behaviors when the passing space R can meet the minimum walking space requirement and the psychological space requirement of the pedestrian, and the pedestrian i and the pedestrian j can be judged to be single behaviors when the R is larger than the threshold value a, otherwise, the pedestrian i and the pedestrian j are interactive behaviors. Since the pedestrian is more restricted when walking at the escalator than at the passageway, the passing space requirement of the pedestrian is relatively small, so the threshold value a is set to 1.8m at the escalator²Typically the lower horizontal channel is 3.5m²。

Step two, if the interaction behavior can occur, the included angle is formed according to the walking direction between the pedestriansTo determine whether an avoidance behavior occurs, as shown in fig. 4. When the pedestrian is in an avoidance behavior, it generally means that the pedestrian i and the pedestrian j do not walk in the same direction, and if the two pedestrians continue to walk in the original direction, there is a high possibility that a collision will occur, so that the walking direction angle between them is surely equal to or greater than 90 ° during avoidance.

Wherein the content of the first and second substances,indicates the direction from the walking direction of the pedestrian i to the walking direction of the pedestrian jAngle between directions, alpha_itAnd alpha_jtRespectively representing the included angles between the walking directions of the pedestrians i and j at the moment t and the Y axis.

If the occurrence condition of the avoidance behavior is not satisfied, the methodAccording to the transverse spacing D between pedestrians_HThe variation quantity is used for judging whether the pedestrian overtaking behavior, the inserting behavior or the following behavior occurs among the pedestrians, and the transverse distance D_HIs set as the distance between the two in the direction perpendicular to the walking direction of the pedestrian.

Calculating the transverse separation D between the pedestrians i and j_HAs shown in fig. 5. The main characteristic of the overtaking behavior and the inserting behavior is that the transverse distance between pedestrians can change, and D is the overtaking behavior_HFrom small to large, during the insertion action D_HFrom big to small, if following, D between pedestrians_HNo change occurs over time. Taking three seconds as a period, marking the transverse distance between two persons in the first second as D_{H plays}And the transverse distance between two persons in the third second is recorded as D_{H terminal}. If it is | D_{H plays}-D_{H terminal}If the | is less than 0, judging that the overtaking action occurs; i D_{H plays}-D_{H terminal}If the | is greater than 0, judging the insertion behavior; i D_{H plays}-D_{H terminal}A following behavior is | ═ 0.

Step three, if the individual behaviors occur among the pedestrians, judging whether the pedestrians have the stay behaviors according to the average walking speed v of the pedestrians; if the occurrence condition of the staying behavior is not met, judging whether the pedestrian has loitering behavior or not by comparing the walking path S of the pedestrian within three seconds with the distance d; otherwise, it is the normal walking behavior.

Since the maximum characteristic of the stopping behavior is that the average speed of the pedestrian is close to 0m/s, the speed v of the pedestrian i in each second after the time t is calculated according to the formula (6) by taking three seconds as a period_it,v_i(t+1),v_i(t+2)Generally, the stride of a person is 0.45-0.5 times of the height of the person, and the average height of the man and the woman in China is calculated to obtain the manHas an average stride length of 75.195-83.55cm and an average stride length of 70.11-77.9cm, so that if the average walking speed in 3 continuous seconds is less than 0.25m/s, namely the pedestrian i only walks about one step in three seconds, the pedestrian i can be judged to have a stopping behavior, wherein d is_itRepresenting the distance traveled by pedestrian i that occurred within t to t +1 seconds.

If the average walking speed of the pedestrian i does not meet the condition, the walking path S of the pedestrian i in three seconds is further calculated by using the formula (7)_i

If the distance d between the t moment and the t +3 moment of the pedestrian i, namely the linear distance between the starting point and the end point of the three seconds, is less than or equal to S/2 and less than or equal to 1.5m, namely the pedestrian still stays in a circle with the center of the circle and the radius of 1.5m after the time of the three seconds, the behavior of loitering can be judged;

and if the conditions are not met, judging that the pedestrian i is in normal walking behavior.

And repeating the third step, and classifying and judging the individual behaviors of the pedestrians j.

And step four, the types of the obstacle avoidance behaviors are only two, namely a retreating behavior and a lane changing behavior, and the behavior can be judged according to the change of the longitudinal coordinate of the pedestrian along with time.

The obstacle avoidance behavior mainly refers to a behavior that when a pedestrian walks in the original direction, the pedestrian encounters an obstacle with an interception function, such as a gate which cannot pass through, a temporarily built guardrail, an upright post, a billboard and the like, and the pedestrian can only avoid the obstacle to continue to advance through a lane changing behavior or a retreating behavior.

The judgment flow of the obstacle avoidance behavior is that when an obstacle appears in video data, the obstacle is likely to appear under the condition of high-density people streamWhen the walking route of the pedestrian is influenced, the walking is executed; otherwise, the flow need not be executed. Because the obstacles in the subway station are generally fixed, the influence range of the obstacles is calibrated in advance, the influence area of the obstacles is set, and the position coordinate of a pedestrian i at the moment t is recorded as (x)_t,y_t) Then the position coordinate at time t +1 is (x)_t+1,y_t+1) If the position coordinate of the pedestrian i is in the obstacle influence area and the change of the vertical coordinate at the time t and the time t +1 is less than 0, the backward action is determined, otherwise, the lane change action is determined.

And step five, repeating the steps one to four, and judging the traffic behavior of the next pedestrian until the judgment of the traffic behaviors of all the pedestrians in the video data is completed.

The method for judging the traffic behaviors of pedestrians at the gate in the Shanghai Di-Fe 9-wire Sijing station comprises the following steps:

firstly, coordinate axes are established in a video picture, as shown in fig. 6, the walking direction of the pedestrian is taken as the y axis, the vertical direction is the x axis, and the actual coordinate information of the pedestrian is conveniently obtained by taking the actual tile length of 0.8m as the scaling scale of the coordinate axes. The detection target in the present embodiment is a red-clothing female (abbreviated as pedestrian 1). And detecting that three persons appear in the current picture totally, and tracking the motion tracks of the three persons in real time respectively. As shown in the following figure, red represents the motion trail of the pedestrian 1, green represents the motion trail of a white-clothing female (pedestrian 2 for short), and purple represents the motion trail of a yellow-clothing female (pedestrian 3 for short).

According to the motion track, the real-time coordinate information of three persons can be directly obtained, the time for tracking the track is shorter because the pedestrian 3 appears in the picture is shorter, and the coordinate information of three persons is shown in the following table.

As can be seen from the table, three persons are detected to be simultaneously present in the screen from 0.8 seconds, whereby the distances d between the pedestrians 2, 3 and the pedestrian 1 and the passing space R can be calculated from their coordinate information, respectively, as shown in the following table.

t(s)	d12(m)	d13(m)	R12(m2)	R13(m2)
					0.8	1.332	5.798	1.392	26.404
0.9	1.341	5.761	1.413	26.069
					1	1.373	5.786	1.482	26.290
1.1	1.374	5.795	1.482	26.372
					1.2	1.368	5.777	1.469	26.212
1.3	1.394	5.803	1.525	26.453
					1.4	1.385	5.814	1.506	26.545
1.5	1.395	5.829	1.528	26.689

The closest pedestrian 2 to pedestrian 3 is determined from the above table. And studies have shown that interaction between pedestrians typically occurs in the range of 3.5m in horizontal lanes²It is inferred that the pedestrian 1 and the pedestrian 2 are likely to meet each otherAnd (4) performing interaction, and calculating characteristic parameters for judging the interaction in the next step. Whether the two people have the avoidance behavior is judged according to the change of the walking direction included angle theta of the two people in the moving process, and the calculation result is shown in the following table.

As can be seen from the above table, the walking direction angles of the pedestrian 1 and the pedestrian 2 are basically unchanged, so the walking direction angle between the two people is also almost equal to 0, which indicates that the two people walk in the same direction, and therefore the possibility of avoiding behavior is eliminated. Next, the transverse distance D between the pedestrian 1 and the pedestrian 2 in the period is compared_HThe results of the calculation are shown in the following table.

From each frame D_HCan be seen in the variation of (1), Δ D_HThe pedestrian is basically floated up and down at about 0m, which indicates that the overtaking and the inserting actions are not generated between the pedestrian 1 and the pedestrian 2, because the transverse distance D between the two pedestrians is generated when the two actions are performed_HA large variation must occur. It is thus determined that the following behavior occurs between the pedestrian 1 and the pedestrian 2.

The distance d between the pedestrian 1 and the pedestrian 2 is calculated manually by taking the foot of the pedestrian as a calibration object through the specific length of the floor tile₁₂Passing space R₁₂Transverse distance D_HAnd the walking direction alpha of the pedestrian 1 is artificially calculated according to the direction of the foot, and the comparison result is shown in the following table and the figure8, we can see that the difference between the discrimination method of the present invention and the actual manual test result is not large, and the present invention basically meets the actual situation.

For the type determination of the obstacle avoidance behavior, firstly, an influence range of an obstacle on a pedestrian needs to be marked in a video, as shown in fig. 7, an obstacle appears in front of a female with black clothes (pedestrian 4 for short), and according to the actual size of the obstacle (the x-axis direction is set to be 1.3m wide, the y-axis direction is set to be 0.3m long), the influence area of the obstacle is set to be a circular area with a radius r of 1.3m, and the circular area is represented by a red circle. Namely, the coordinates (x, y) of the block area range from (0.159 to 2.759,1.019 to 3.619).

The position coordinate information of the pedestrian 4 in the video data is obtained according to the motion trail tracking, as shown in the following table.

It can be seen that the pedestrian 4 enters the influence area of the obstacle from 4.5 seconds, so that the pedestrian is determined to be in the obstacle avoidance behavior definitely. Next, the change of the ordinate y of the pedestrian 4 within these 4.5s to 7.5s is calculated, and the results are shown in the following table.

The calculation result shows that the change of the ordinate is always larger than 0, which indicates that the pedestrian does not have the backward movement behavior. We can also verify whether the pedestrian 4 has made a lane change by calculating the change in the pedestrian abscissa x. The cumulative abscissa change of the pedestrian 4 in the time period of 4.5s to 7.5s is 0.892m, which is already over half the width of the obstacle, so that it can also be verified that the pedestrian 4 has performed lane change while facing the obstacle.

The verification results are shown in the following table and fig. 9, and it can be seen that the difference between the discrimination method of the present invention and the actual manual test results is not large, and the results substantially conform to the actual situation.

Although particular embodiments of the present invention have been described above, it will be understood by those skilled in the art that these are by way of example only and that various changes or modifications may be made to these embodiments without departing from the spirit and scope of the invention and, therefore, the scope of the invention is to be defined by the appended claims.