JP2019016082A - Congestion prediction device and congestion prediction method therefor - Google Patents

Abstract

To provide a congestion prediction device and a congestion prediction method therefor capable of suppressing a reduction in prediction accuracy related to congestion, and suppressing a processing load.SOLUTION: A congestion prediction device comprises: first and second calculation parts 51e, 51f for calculating a first inter-vehicle distance to a front vehicle on an own traffic lane and a second inter-vehicle distance to a front vehicle on a passing lane on the basis of image information from an on-vehicle camera; a determination part 51g for determining whether or not predetermined linearity exists between the second inter-vehicle distance calculated in the previous time or before the previous time and the first inter-vehicle distance to be calculated at present time or after the present time when the first or second inter-vehicle distance changes by a predetermined value or more in comparison with a value of the previous time or before the previous time; an event determination part 51b for determining that a passing event has occurred when it is determined that the predetermined linearity exists by the determination part 51g; and a congestion prediction part 51h for predicting occurrence of congestion on the basis of a frequency of the passing event determined by the event determination part 51b.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a traffic jam prediction apparatus and a traffic jam prediction method.

  Conventionally, a traffic counter that monitors the passage of a vehicle by using a change in geomagnetism is provided on a road surface of an expressway. In addition, a traffic jam prediction device that predicts traffic jam on an expressway based on information from such a traffic counter has also been proposed (see, for example, Patent Document 1). Since this device is premised on communication with a traffic counter, it is inferior in real-time property, for example, receiving information every 5 minutes, leading to a decrease in the accuracy of traffic jam prediction.

  In view of this, a traffic jam prediction device has been proposed that predicts traffic jam based on information acquired by the host vehicle, regardless of information from the traffic counter. In such a traffic jam prediction device, for example, based on the idea that acceleration fluctuations such as stepping on the brake or accelerating immediately before the traffic jam occurs, the frequency of the acceleration is analyzed (Fourier transform) to generate the traffic jam. (See Patent Document 2). Also, when trying to change lanes, determine the number of vehicles traveling ahead of the preceding vehicle (vehicles traveling immediately before the host vehicle) of the own lane, and determine whether there is congestion in front of the preceding vehicle. A traffic jam judging device for judging has also been proposed (see Patent Document 3).

JP 2006-309735 A JP 2012-128614 A JP 2016-16829 A

  However, the traffic jam prediction device described in Patent Document 2 predicts the occurrence of traffic jam by frequency analysis (Fourier transform) of acceleration, so that the processing load is never low.

  Further, with the traffic jam judging device described in Patent Document 3, traffic jam can be judged only when a vehicle ahead of a preceding vehicle such as when changing lanes can be seen. For this reason, the traffic jam judging device described in Patent Document 3 may not be able to judge traffic jams for a long period of time depending on the driving situation, and lacks real-time performance and causes a decrease in the accuracy of traffic jam prediction, as in the case of using a traffic counter. There was a possibility that.

  The present invention has been made to solve such a problem, and the object of the present invention is to suppress a decrease in prediction accuracy related to a traffic jam and a traffic jam prediction device capable of suppressing a processing load and its It is to provide a traffic jam prediction method.

  The traffic jam prediction device according to the present invention includes a first calculation means for obtaining a first inter-vehicle distance to a preceding vehicle in the own lane that is the traveling lane of the own vehicle, based on information from a mounting device mounted on the own vehicle; Based on information from the mounting device mounted on the vehicle, second calculation means for obtaining a second inter-vehicle distance to the preceding vehicle in the overtaking lane adjacent to the own lane, and the second calculation means obtained by the first calculation means When the first inter-vehicle distance or the second inter-vehicle distance obtained by the second calculation means changes by a predetermined value or more compared to the previous value, the second calculation means calculates the first A first determination means for determining whether or not there is a predetermined linearity between a distance between two vehicles and the first inter-vehicle distance calculated after this time by the first calculation means; and a predetermined determination by the first determination means. Determined to be linear A second determination unit that determines that an overtaking event has occurred, and a traffic jam prediction unit that predicts the occurrence of a traffic jam based on the frequency of the overtaking event determined by the second determination unit. It is characterized by.

  According to this traffic jam prediction device, the first inter-vehicle distance that is the inter-vehicle distance of the preceding vehicle in the own lane or the second inter-vehicle distance that is the inter-vehicle distance of the preceding vehicle in the overtaking lane is predetermined compared to the previous value. When it changes more than the value, it is determined whether there is a predetermined linearity between the second inter-vehicle distance before the previous time and the first inter-vehicle distance after this time. Here, for example, an overtaking vehicle that overtakes the own vehicle travels in the overtaking lane at a certain speed, overtakes the own vehicle, and then enters the own lane. In this way, the overtaking vehicle travels in a series of flows, and the over-vehicle distance when the overtaking vehicle is traveling in the overtaking lane and the inter-vehicle distance in traveling after entering the own lane are also set. It will have linearity (continuity). For this reason, it is possible to determine the overtaking event of the host vehicle by determining the linearity of the inter-vehicle distance. Here, the inventors of the present invention have found that the number of overtaking events increases in a stage before traffic jam occurs. For this reason, it is possible to predict the occurrence of a traffic jam based on the frequency of the overtaking event. In particular, information from the traffic counter is not required, and it is only necessary to detect the vehicle ahead of the own lane and the vehicle ahead of the overtaking lane. Therefore, real-time property can be improved and the fall of the prediction precision regarding a traffic jam can be suppressed. Furthermore, processing such as Fourier transform is not necessary, and the processing load can be suppressed. From the above, it is possible to provide a traffic jam prediction device that can suppress a decrease in prediction accuracy related to traffic jams and can also reduce processing load.

  In addition, in the traffic jam prediction device, it is preferable that the traffic jam prediction device further includes warning means for performing a driving warning for alleviating the occurrence of the traffic jam to the driver of the host vehicle when the traffic jam forecasting unit predicts the occurrence of the traffic jam. .

  According to this traffic jam prediction device, driving warnings for mitigating the occurrence of traffic jams are given to the driver of the host vehicle. it can.

  The traffic jam prediction apparatus further includes speed signal input means for inputting a signal corresponding to the speed of the host vehicle, wherein the traffic jam prediction means is a speed of the host vehicle corresponding to the signal input by the speed signal input means. Is not less than the speed obtained by adding the predetermined speed to the legal speed, it is preferable to prohibit the prediction of the occurrence of traffic jam.

  According to this traffic jam prediction device, in order to prohibit the prediction of the occurrence of traffic jam when the speed of the own vehicle is not less than the speed obtained by adding the predetermined speed to the legal speed, for example, the overtaking side rather than overtaking the own vehicle In such a case, the traffic jam is not predicted, and the decrease in the prediction accuracy regarding the traffic jam can be further suppressed.

  In the traffic jam prediction method of the traffic jam prediction device according to the present invention, the first inter-vehicle distance to the preceding vehicle in the own lane that is the traveling lane of the own vehicle is obtained based on the information from the mounting device installed in the own vehicle. A first calculating step, a second calculating step for obtaining a second inter-vehicle distance to a preceding vehicle in an overtaking lane adjacent to the traveling lane of the own vehicle based on information from a mounting device mounted on the own vehicle; In the second calculation step, when the first inter-vehicle distance obtained in the first calculation step or the second inter-vehicle distance obtained in the second calculation step changes by a predetermined value or more compared to the previous value. A first determination step of determining whether or not there is a predetermined linearity between the second inter-vehicle distance calculated before the previous time and the first inter-vehicle distance calculated after the current time in the first calculation step; , The first judgment When it is determined that there is a predetermined linearity, a second determination step for determining that an overtaking event has occurred, and a frequency of the overtaking event based on the frequency of the overtaking event determined in the second determination step. And a traffic jam prediction step for predicting the occurrence.

  According to the traffic jam prediction method of the traffic jam prediction device, the first inter-vehicle distance that is the inter-vehicle distance of the preceding vehicle in the own lane or the second inter-vehicle distance that is the inter-vehicle distance of the forward vehicle in the overtaking lane is the previous value. When the comparison changes more than a predetermined value, it is determined whether there is a predetermined linearity between the second inter-vehicle distance before the previous time and the first inter-vehicle distance after this time. Here, for example, an overtaking vehicle that overtakes the own vehicle travels in the overtaking lane at a certain speed, overtakes the own vehicle, and then enters the own lane. In this way, the overtaking vehicle travels in a series of flows, and the over-vehicle distance when the overtaking vehicle is traveling in the overtaking lane and the inter-vehicle distance in traveling after entering the own lane are also set. It will have linearity (continuity). For this reason, it is possible to determine the overtaking event of the host vehicle by determining the linearity of the inter-vehicle distance. Here, the inventors of the present invention have found that the number of overtaking events increases in a stage before traffic jam occurs. For this reason, it is possible to predict the occurrence of a traffic jam based on the frequency of the overtaking event. In particular, information from the traffic counter is not required, and it is only necessary to detect the vehicle ahead of the own lane and the vehicle ahead of the overtaking lane. Therefore, real-time property can be improved and the fall of the prediction precision regarding a traffic jam can be suppressed. Furthermore, processing such as Fourier transform is not necessary, and the processing load can be suppressed. From the above, it is possible to provide a traffic jam prediction device that can suppress a decrease in prediction accuracy related to traffic jams and can also reduce processing load.

  ADVANTAGE OF THE INVENTION According to this invention, the congestion prediction apparatus which can suppress the fall of the prediction precision regarding a traffic jam, and can also suppress a processing load, and its traffic jam prediction method can be provided.

It is a block diagram which shows the structure of the vehicle-mounted system containing the congestion prediction apparatus which concerns on embodiment of this invention. It is a functional block diagram of the control part shown in FIG. It is a top view which shows the driving environment of the own vehicle. It is a figure which shows the time change of the 1st and 2nd inter-vehicle distance at the time of a passing event. It is a figure which shows the correlation with the number of overtaking events in a predetermined time, and traffic density. It is a flowchart which shows the traffic jam prediction method by the traffic jam prediction apparatus concerning this embodiment. It is a graph which shows the actual measurement value of the 1st inter-vehicle distance and the 2nd inter-vehicle distance.

  Hereinafter, the present invention will be described according to preferred embodiments. Note that the present invention is not limited to the embodiments described below, and can be appropriately changed without departing from the spirit of the present invention. Further, in the embodiment described below, there is a part where illustration or description of a part of the configuration is omitted, but details of the omitted technology are within a range in which there is no contradiction with the contents described below. Needless to say, known or well-known techniques are applied as appropriate.

  FIG. 1 is a block diagram showing a configuration of an in-vehicle system including a traffic jam prediction apparatus according to an embodiment of the present invention. As shown in FIG. 1, an in-vehicle system 1 is a system mounted in a vehicle, and includes an in-vehicle camera (mounted device) 10, a vehicle speed sensor 20, a GPS (Global Positioning System) receiver 30, and a drive recorder. The apparatus 50 is comprised.

  The in-vehicle camera 10 is an imaging device that is mounted on the host vehicle and can capture the front including at least the host lane that is the lane in which the host vehicle travels and the overtaking lane adjacent to the host lane. The vehicle speed sensor 20 outputs a pulse signal corresponding to the speed of the host vehicle (wheel rotation). The GPS receiver 30 receives radio waves from GPS satellites, calculates the current position of the vehicle based on radio wave signals received from each of the plurality of GPS satellites, and uses the calculated current position information as a drive recorder device. 50 is output.

  The drive recorder device 50 records the operation record in the memory card 40 by using the captured image signal obtained by the imaging of the in-vehicle camera 10, the pulse signal from the vehicle speed sensor 20, and the current position information from the GPS receiver 30. It is something to do. The memory card 40 is a recording medium owned by the driver, and the operation record stored in the memory card 40 is subjected to data analysis by an analysis device such as a management company. The operation record may be transmitted to a management company or the like by communication using an antenna 58 described later after being recorded on a recording medium in the device 50, or information on the operation record as needed. May be transmitted to the cloud server via the antenna 58 described later and stored (recorded).

  The drive recorder device 50 includes a control unit 51, an image processing unit 52, a G (Gravity) sensor 53, a speaker (warning unit) 54, a speed interface (speed signal input unit) 55, and a GPS interface (speed signal input). Means) 56, a memory card interface 57, and an antenna 58. Among these components, the control unit 51, the speaker 54, and the speed interface 55 (or a GPS interface 56 as will be described later) constitute the traffic jam prediction device 100 according to the present embodiment.

  The control unit 51 controls the entire drive recorder device 50. The image processing unit 52 receives a video signal output from the in-vehicle camera 10, generates data representing brightness and color for each of a number of pixels constituting the frame for each frame of the video, and sets a set of these pixels. This is output to the control unit 51 as image data.

  The G sensor 53 outputs a signal indicating the magnitude of acceleration applied to the host vehicle to the control unit 51 in each direction of three axes orthogonal to each other. Under the control of the control unit 51, the speaker 54 outputs, for example, a warning sound or messages such as various warnings and guidance using a synthesized pseudo audio signal as sound. As will be described later, the speaker 54 functions as a warning means for performing a driving warning to alleviate the occurrence of traffic congestion.

  The speed interface 55 serves as an input part for inputting a pulse signal (a signal corresponding to the speed of the host vehicle) from the vehicle speed sensor 20. The GPS interface 56 is a connection part with the GPS receiver 30. In addition, since the GPS receiver 30 calculates the present position of the own vehicle, it is also possible to calculate the speed of the own vehicle from the moving distance and time. In this case, the GPS interface 56 functions as an input part for inputting a signal corresponding to the speed of the host vehicle.

  The memory card interface 57 is constituted by, for example, a card slot into which the memory card 40 is inserted. By inserting the memory card 40 into the memory card interface 57, the drive recorder device 50 can write information such as the speed of the own vehicle and image data to the memory card 40. Note that the configuration of the memory card interface 57 may be unnecessary when information such as operation records is not recorded in the memory card 40 but is transmitted to the communication destination for recording.

  FIG. 2 is a functional block diagram of the control unit 51 shown in FIG. As shown in FIG. 2, the control unit 51 executes a program stored in a ROM or an external storage medium, thereby executing a host vehicle speed calculation unit 51 a, an event determination unit (second determination unit) 51 b, A first recording unit 51c, a second recording unit 51d, a first calculation unit (first calculation unit) 51e, a second calculation unit (second calculation unit) 51f, a determination unit (first determination unit) 51g, A traffic jam prediction unit (traffic jam prediction means) 51h and a warning control unit 51i function.

  The own vehicle speed calculation unit 51 a is a functional unit that calculates the speed of the own vehicle based on the pulse signal from the vehicle speed sensor 20. The event determination unit 51b determines whether an acceleration sudden change event (accident or near-miss condition) has occurred. Based on the acceleration signal from the G sensor 53, the event determination unit 51b determines that the change is an acceleration corresponding to an accident or a near-miss state when there is a change in the acceleration by a predetermined value or more, and suddenly changes the acceleration. It is determined that an event has occurred. Furthermore, the event determination unit 51b also determines that an overtaking event has occurred when the determination unit 51g determines that there is predetermined linearity described later.

  The first recording unit 51c is a functional unit that records information on the speed of the host vehicle when the vehicle is traveling in a communication destination such as the memory card 40 or a cloud server. The second recording unit 51d is a functional unit that records video information obtained by imaging by the in-vehicle camera 10 in a communication destination such as the memory card 40 or a cloud server. This 2nd recording part 51d records the information of the image | video from the vehicle-mounted camera 10 always. Note that the second recording unit 51d has a predetermined time at least one before and after the event occurrence time (the time when the acceleration changes more than a specified value) when the event determination unit 51b determines that an abrupt acceleration change event has occurred. Only video information may be recorded.

  The first calculation unit 51e calculates a first inter-vehicle distance from the image ahead of the host vehicle obtained based on the in-vehicle camera 10 to the preceding vehicle in the host lane that is the traveling lane of the host vehicle. For example, the first calculation unit 51e performs template matching from the front image of the vehicle, detects the front vehicle in the own lane, calculates the distance from the detected position on the front vehicle image to the front vehicle, The first inter-vehicle distance. For example, white line detection technology is used for specifying the lane. The first calculation unit 51e is not limited to detecting a forward vehicle by template matching, and may employ other known or well-known detection methods such as using an optical flow.

  The second calculator 51f calculates a second inter-vehicle distance from the image ahead of the host vehicle obtained based on the in-vehicle camera 10 to the preceding vehicle in the overtaking lane adjacent to the host vehicle. Similarly to the first calculation unit 51e, the second calculation unit 51f also detects a vehicle ahead in the overtaking lane using a known or well-known detection method or the like, and obtains the second inter-vehicle distance.

  When the first inter-vehicle distance obtained by the first calculating unit 51e or the second inter-vehicle distance obtained by the second calculating unit 51f changes by a predetermined value or more compared to the previous value, the determining unit 51g In addition, it is determined whether there is a predetermined linearity between the second inter-vehicle distance calculated before the previous time by the second calculating unit 51f and the first inter-vehicle distance calculated after this time by the first calculating unit 51e. Is. The event determination unit 51b determines that an overtaking event has occurred when the determination unit 51g determines that there is a predetermined linearity.

  Note that the value before the previous time in the above may be the previous value, the value before the previous time, the average value for the past several times, or the like, and can be set in various ways. The predetermined value may be a predetermined fixed value or a variable value that varies based on the previous value or the like. Furthermore, the predetermined value may differ depending on whether the comparison target is the first inter-vehicle distance or the second inter-vehicle distance.

  FIG. 3 is a top view showing the traveling environment of the host vehicle. As shown in FIG. 3, for example, there is a host lane that is a travel lane on which the host vehicle travels, and an overtaking lane exists adjacent thereto. The distance to the front vehicle FV1 on the own lane (that is, the first inter-vehicle distance) is h1, and the distance to the front vehicle FV2 on the overtaking lane (that is, the second inter-vehicle distance) is hr. Furthermore, since it is considered that the forward vehicle FV2 is traveling faster than the own vehicle, the relationship of the speed v2 of the forward vehicle FV2 in the overtaking lane> the speed v1 of the own vehicle is established.

  FIG. 4 is a diagram showing temporal changes in the first and second inter-vehicle distances h1 and hr when the overtaking event occurs. As shown in FIG. 4, for example, at time t1, the first inter-vehicle distance h1 calculated by the first calculating unit 51e is a, and the second inter-vehicle distance hr calculated by the second calculating unit 51f is b. To do.

  Thereafter, it is assumed that the forward vehicle FV2 in the overtaking lane shown in FIG. 3 enters the own lane at time t2. At this time, the forward vehicle FV2 on the overtaking lane is recognized by the traffic jam prediction device 100 as the forward vehicle FV1 on the own lane after entering the own lane. Therefore, as shown in FIG. 4, the values of the first inter-vehicle distance h1 and the second inter-vehicle distance hr rapidly change near the time t2.

  In addition, since the forward vehicle FV2 before the time t2 and the forward vehicle FV1 after the time t2 are the same vehicle, the second inter-vehicle distance hr of the forward vehicle FV2 before the time t2 and the first vehicle FV1 after the time t2 The inter-vehicle distance h1 should change in the same way. Therefore, predetermined linearity (continuity) exists between the second inter-vehicle distance hr before the time t2 and the first inter-vehicle distance h1 after the time t2.

  Thus, when the forward vehicle FV2 in the overtaking lane enters the own lane, 1) the first and second inter-vehicle distances h1 and hr fluctuate rapidly, and 2) the second inter-vehicle distance before the fluctuation It can be said that there is a predetermined linearity between the distance hr and the first inter-vehicle distance h1 after the change. Therefore, when the first or second inter-vehicle distance h1, hr changes by a predetermined value or more compared to the previous value, the determining unit 51g determines the predetermined distance between the second inter-vehicle distance hr and the first inter-vehicle distance h1. The event determination unit 51b determines that an overtaking event has occurred when it is determined that there is a predetermined linearity.

  Needless to say, at least three pieces of information on the first and second inter-vehicle distances h1 and hr are necessary for determining the predetermined linearity. For example, the determination unit 51g calculates a straight line y = ax + b that connects the previous and previous second inter-vehicle distance hr, and is within a predetermined range centered on the straight line (for example, a range of y = ax + bc to y = ax + b + c). In this case, c may be a fixed value or a variable value), and if the current first inter-vehicle distance h1 falls within this range, it is determined that there is a predetermined linearity. In determining the predetermined linearity, at least three pieces of information on the first and second inter-vehicle distances h1 and hr are required. However, the accuracy is improved by using more than four values. Needless to say. Further, instead of the straight line y = ax + b connecting the second inter-vehicle distance hr in the previous time and the previous time, an approximate expression using a least square method or the like may be adopted for the values of three or more second inter-vehicle distances hr. . Furthermore, the approximate expression is not limited to the case of obtaining only from the value of the second inter-vehicle distance hr, and may include a part of the first inter-vehicle distance h1, or may be obtained only from the first inter-vehicle distance h1. In particular, an approximate expression may be obtained based on a plurality of first inter-vehicle distances h1 after this time, and it may be determined whether the second inter-vehicle distance hr at a specific time in the past is within a predetermined range of the approximate expression. In addition, the three pieces of information necessary for determining the linearity preferably include the current first inter-vehicle distance h1 and the previous second inter-vehicle distance hr. However, the present invention is not limited to this, and is not included. Also good.

  Refer to FIG. 2 again. The traffic jam prediction unit 51h predicts the occurrence of traffic jam based on the frequency of the overtaking event determined by the event determination unit 51b. Here, the inventors of the present invention have found that the number of overtaking events increases in a stage before traffic jam occurs.

  FIG. 5 is a diagram showing the correlation between the number of overtaking events and the traffic density in a predetermined time. In FIG. 5, a region where the traffic density is higher than the critical line indicated by a broken line is a region where traffic congestion occurs, and a region where the traffic density is lower than the critical line is a region where traffic congestion does not occur.

  When the traffic density is high and the roads are crowded, the driver of the vehicle tends to overtake other vehicles from the consciousness of arriving at the destination as soon as possible. As shown in FIG. The number of overtaking events in is the largest. On the other hand, if the vehicle gets stuck in a traffic jam, the vehicle traveling in the overtaking lane does not return to the traveling lane (the own lane shown in FIG. 3) and travels in the overtaking lane as it is. .

  Therefore, it can be said that the traffic jam prediction unit 51h can predict the occurrence of the traffic jam based on the frequency of the overtaking event determined by the event determination unit 51b.

  Refer to FIG. 2 again. The warning control unit 51i generates a driving warning from the speaker 54 for alleviating the occurrence of the traffic jam for the driver of the host vehicle when the traffic jam prediction unit 51h predicts the occurrence of the traffic jam.

  Here, the driving warning to alleviate the occurrence of traffic congestion is a warning that prompts the driver to maintain the distance between vehicles or to keep the vehicle speed constant. For example, “Please keep driving and drive with low acceleration. Is a voice warning. In addition, it is possible to reduce the occurrence of traffic congestion (suppress growth) by prompting a slow-in at 5 km before entering a traffic jam. For example, "Please reduce the speed to XX km / h". An audio warning applies.

  Next, a traffic jam prediction method by the traffic jam prediction device 100 according to the present embodiment will be described. FIG. 6 is a flowchart showing a traffic jam prediction method by the traffic jam prediction device 100 according to the present embodiment. As shown in FIG. 6, first, the speed interface 55 inputs a pulse signal from the vehicle speed sensor 20 (S1). Next, the host vehicle speed calculation unit 51a calculates the host vehicle speed v1 based on the pulse signal from the vehicle speed sensor 20 (S2).

  Next, the traffic jam prediction unit 51h determines whether or not the speed v1 of the host vehicle calculated in step S2 is equal to or lower than the speed obtained by adding the predetermined speed α to the legal speed (S3). If it is determined that the speed is not less than the speed obtained by adding the predetermined speed α to the legal speed (S3: NO), it can be determined that the host vehicle is too fast and is not overtaken. Migrate to The predetermined speed α may be a fixed value such as 5 km / h, or may be a variable value such as 10% of the legal speed. The legal speed can be specified from position information obtained via the GPS receiver 30 and map information stored in advance.

  On the other hand, when it is determined that the speed is equal to or lower than the speed obtained by adding the predetermined speed α to the legal speed (S3: YES), the first calculation unit 51e determines that the first calculation unit 51e is A first inter-vehicle distance h1 to the forward vehicle FV1 in the lane is calculated (S4). Next, the second calculation unit 51f calculates the second inter-vehicle distance hr from the front image of the host vehicle obtained by the processing by the image processing unit 52 to the front vehicle FV2 in the overtaking lane (S5). The calculated first and second inter-vehicle distances h1 and hr are recorded in the internal memory of the control unit 51, the memory card 40, or the cloud server.

  Thereafter, the determination unit 51g determines whether the second inter-vehicle distance hr obtained in step S5 has changed by a predetermined value or more compared to the previous value (S6). In the process of step S6, the previous time value may be adopted instead of the previous value, or an average value for the past several times may be adopted. Furthermore, in the process of step S6, it may be determined whether the first inter-vehicle distance h1 obtained in step S4 has changed by a predetermined value or more, not the change in the second inter-vehicle distance hr obtained in step S5. Then, it may be determined whether or not both have changed by a predetermined value or more. In addition, the predetermined value may be a fixed value or a variable value.

  If it is determined that the value has not changed more than the predetermined value (S6: NO), the process proceeds to step S1. If it is determined that the value has changed by a predetermined value or more (S6: YES), the determination unit 51g calculates the three or more second inter-vehicle distances hr calculated in the past step S5 and the first inter-vehicle distance calculated in the current step S4. It is determined whether there is a predetermined linearity with the distance h1 (S7). In this process, the determination unit 51g obtains an approximate expression from three or more second inter-vehicle distances hr, and determines whether the current first inter-vehicle distance h1 is within a predetermined range of the approximate expressions.

  FIG. 7 is a graph showing measured values of the first inter-vehicle distance h1 and the second inter-vehicle distance hr. In the graph shown in FIG. 7, it is assumed that the first inter-vehicle distance h1 and the second inter-vehicle distance hr are calculated about every 1 second. In FIG. 7, the case where the second inter-vehicle distance hr is 0 m indicates a case where the forward vehicle FV2 in the overtaking lane cannot be detected.

  As shown in FIG. 7, from the time of 9:52:42 to 47 seconds, the second inter-vehicle distance hr with the forward vehicle FV2 in the overtaking lane is about 24 m to 25 m. For example, the determination unit 51g calculates an approximate expression based on the data of the past five second inter-vehicle distances hr. The approximate expression is shown by a one-dot chain line in FIG.

  Furthermore, the determination unit 51g sets a predetermined range obtained by adding or subtracting a specific value to the calculated approximate expression. The predetermined range is indicated by a broken line. The determination unit 51g determines whether the first inter-vehicle distance h1 calculated this time is within the predetermined range. In the example shown in FIG. 7, the first inter-vehicle distance h1 calculated this time is within a predetermined range. For this reason, the determination part 51g determines with having a predetermined linearity.

  In the above, the approximate expression is calculated based on the data of the past five second inter-vehicle distances hr, but is not limited to five in particular, and is calculated based on three, four, or six or more data. Also good. Moreover, not only an approximate expression but a straight line may be calculated | required based on the data of two 2nd inter-vehicle distance hr. Furthermore, the calculation timing of the approximate expression or the like may be performed several times after the processing, and the approximate expression may be calculated including not only the data of the second inter-vehicle distance hr but also the data of the first inter-vehicle distance h1, or the first inter-vehicle distance An approximate expression may be calculated from only the data of h1. In addition, the determination unit 51g determines whether the first inter-vehicle distance h1 calculated this time is within a predetermined range, but is not particularly limited to the first inter-vehicle distance h1 calculated this time. It may be determined whether the first inter-vehicle distance h1 is within a predetermined range.

  Refer to FIG. 6 again. If it is determined that there is no predetermined linearity (S7: NO), the process proceeds to step S1. On the other hand, when it is determined that there is a predetermined linearity (S7: YES), the traffic jam prediction unit 51h determines that there is an overtaking event, and also determines whether there has been an overtaking event equal to or more than the threshold Tx within the past predetermined time. (S8).

  If it is determined that there has been no overtaking event within the predetermined time in the past (S8: NO), the process proceeds to step S1. On the other hand, if it is determined that there has been an overtaking event that is equal to or greater than the threshold Tx within the past predetermined time (S8: YES), the traffic jam prediction unit 51h predicts the occurrence of traffic jam (S9). Next, the warning control unit 51i generates a driving warning from the speaker 54 to alleviate the occurrence of traffic congestion for the driver of the host vehicle (S10). Then, the process shown in FIG. 6 ends.

  Thus, according to the traffic jam prediction device 100 and the traffic jam prediction control method according to the present embodiment, the first inter-vehicle distance h1 that is the inter-vehicle distance of the forward vehicle FV1 in the own lane or the forward vehicle FV2 in the overtaking lane. When the second inter-vehicle distance hr, which is the inter-vehicle distance, has changed by a predetermined value or more compared to the previous value, a predetermined interval between the second inter-vehicle distance hr before the previous time and the first inter-vehicle distance h1 after this time Determine if there is linearity. Here, for example, an overtaking vehicle that overtakes the own vehicle travels in the overtaking lane at a certain speed, overtakes the own vehicle, and then enters the own lane. In this way, the overtaking vehicle travels in a series of flows, and the over-vehicle distance when the overtaking vehicle is traveling in the overtaking lane and the inter-vehicle distance in traveling after entering the own lane are also set. It will have linearity (continuity). For this reason, it is possible to determine the overtaking event of the host vehicle by determining the linearity of the inter-vehicle distance. Here, the inventors of the present invention have found that the number of overtaking events increases in a stage before traffic jam occurs. For this reason, it is possible to predict the occurrence of a traffic jam based on the frequency of the overtaking event. In particular, information from the traffic counter is not required, and it is only necessary to detect the forward vehicle FV1 in the own lane and the forward vehicle FV2 in the overtaking lane. Therefore, real-time property can be improved and the fall of the prediction precision regarding a traffic jam can be suppressed. Furthermore, processing such as Fourier transform is not necessary, and the processing load can be suppressed. As described above, it is possible to provide the traffic jam prediction device 100 and the traffic jam prediction method capable of suppressing the decrease in the prediction accuracy related to the traffic jam and the processing load.

  Further, since a driving warning for alleviating the occurrence of traffic jams is given to the driver of the host vehicle, for example, it is possible to support throw-in before the traffic jams occur and contribute to the reduction of traffic jams.

  Further, in order to prohibit the prediction of the occurrence of traffic congestion when the speed v1 of the own vehicle is not less than the speed obtained by adding the predetermined speed α to the legal speed, for example, the own vehicle seems to be overtaking rather than being overtaken. In such a case, the traffic jam is not predicted, and the decrease in the prediction accuracy related to the traffic jam can be further suppressed.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and may be modified without departing from the spirit of the present invention, and may be appropriately changed within a possible range. These techniques may be combined. Furthermore, known or well-known techniques may be combined within a possible range.

  For example, in the above, the driving warning for reducing the occurrence of traffic congestion is performed by voice output, but the present invention is not limited to this, and the warning may be performed by an image.

  In the above embodiment, the in-vehicle camera 10 is mounted and the inter-vehicle distance is calculated using an image from the in-vehicle camera 10. However, the present invention is not limited to this, and the radar apparatus (an example of the mounted apparatus) is mounted. The inter-vehicle distance may be calculated using a signal from. Further, if possible, the inter-vehicle distance may be calculated using a signal from another device (an example of a mounting device) mounted on the host vehicle.

  Further, in the above embodiment, the information on the prediction of occurrence of traffic jam determined in step S9 and the information on driving warning in step S10 may be transmitted to the following vehicle using communication. And a driving warning may be performed in the following vehicle. Furthermore, in this embodiment, the occurrence of traffic jam is predicted from information acquired in one vehicle. However, the present invention is not limited to this, and the occurrence of traffic jam may be predicted by integrating a plurality of information.

  Furthermore, in FIG. 3 described above, the description has been given with reference to a road on one side with two lanes. However, it is needless to say that the traffic jam prediction device 100 is applicable not only to a road with two lanes on one side but also to a road with three or more lanes on one side. Here, for example, assuming that the host vehicle is traveling in the leftmost lane on a road with three lanes on one side, the traffic jam prediction device 100 executes the above processing with the middle lane as the overtaking lane. Further, assuming that the host vehicle is traveling in the middle lane, the traffic jam prediction device 100 executes the above processing with the rightmost lane as the overtaking lane. The same is true for four or more lanes.

  Further, the determination of the linearity is not limited to the above-described one. For example, the determination unit 51g calculates an approximate expression for the second inter-vehicle distance hr for the past five times in the actual measurement value shown in FIG. Approximation formulas for the first inter-vehicle distance h1 may be calculated, and linearity may be determined based on whether the slopes of these approximation formulas are close or whether the intercept values are close. Further, if possible, it may be determined that there is linearity when the difference between the previous second inter-vehicle distance hr and the current first inter-vehicle distance h1 is equal to or less than a specified value. Furthermore, the method is not limited to these, and a known or well-known linearity determination method may be employed.

  In addition, in FIG. 3 described above, the road environment in Japan or the United Kingdom where the vehicle is on the left side is described. However, the traffic jam prediction device 100 is used when the vehicle such as the United States, Germany, and France is on the right side. Is also applicable.

100: Traffic jam prediction device 1: In-vehicle system 10: In-vehicle camera (equipped device)
20: Vehicle speed sensor 30: GPS receiver 40: Memory card 50: Drive recorder device 51: Control unit 51a: Own vehicle speed calculation unit 51b: Event determination unit (second determination means)
51c: first recording unit 51d: second recording unit 51e: first calculation unit (first calculation means)
51f: 2nd calculation part (1st calculation means)
51g: determination unit (first determination means)
51h: Traffic jam prediction unit (traffic jam prediction means)
51i: Warning control unit 52: Image processing unit 53: G sensor 54: Speaker (warning means)
55: Speed interface (speed signal input means)
56: GPS interface (speed signal input means)
57: Memory card interface 58: Antenna FV1: Vehicle in front of own lane FV2: Vehicle in front of overtaking lane

Claims (4)

First calculation means for obtaining a first inter-vehicle distance to a preceding vehicle in the own lane, which is a traveling lane of the own vehicle, based on information from a mounting device mounted on the own vehicle;
A second calculating means for obtaining a second inter-vehicle distance to a preceding vehicle in an overtaking lane adjacent to the own lane based on information from a mounting device mounted on the own vehicle;
The second calculation when the first inter-vehicle distance obtained by the first calculation means or the second inter-vehicle distance obtained by the second calculation means has changed by a predetermined value or more compared to the previous value. A first determination for determining whether or not there is a predetermined linearity between the second inter-vehicle distance calculated by the means before the previous time and the first inter-vehicle distance calculated by the first calculation means after the current time Means,
Second determination means for determining that an overtaking event has occurred when the first determination means determines that there is a predetermined linearity;
A traffic jam prediction unit for predicting the occurrence of traffic jam based on the frequency of the overtaking event determined by the second determination unit;
A traffic jam prediction device comprising: 2. The apparatus according to claim 1, further comprising a warning unit that issues a driving warning for alleviating the occurrence of the traffic jam to the driver of the host vehicle when the traffic jam is predicted by the traffic jam prediction unit. Traffic jam prediction device. It further comprises speed signal input means for inputting a signal according to the speed of the host vehicle,
The traffic jam prediction means prohibits the prediction of the occurrence of traffic jam when the speed of the host vehicle according to the signal input by the speed signal input means is not less than a speed obtained by adding a predetermined speed to a legal speed. The traffic jam prediction apparatus according to claim 1 or 2. A first calculation step for obtaining a first inter-vehicle distance to a preceding vehicle in the own lane, which is a traveling lane of the own vehicle, based on information from a mounting device mounted on the own vehicle;
A second calculation step for obtaining a second inter-vehicle distance to a preceding vehicle in an overtaking lane adjacent to the traveling lane of the own vehicle based on information from a mounting device mounted on the own vehicle;
The second calculation is performed when the first inter-vehicle distance obtained in the first calculation step or the second inter-vehicle distance obtained in the second calculation step changes by a predetermined value or more compared to the previous value. A first determination for determining whether or not there is a predetermined linearity between the second inter-vehicle distance calculated before the previous time in the step and the first inter-vehicle distance calculated after the current time in the first calculation step. Process,
A second determination step of determining that an overtaking event has occurred when it is determined that there is a predetermined linearity in the first determination step;
Based on the frequency of the overtaking event determined in the second determination step, a traffic jam prediction step for predicting the occurrence of traffic jams,
A traffic jam prediction method for a traffic jam forecasting device.

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