JP5333249B2 - Traffic jam occurrence prediction device and traffic jam occurrence suppression device - Google Patents

Description

  The present invention relates to a traffic jam occurrence prediction device and a traffic jam occurrence suppression device that predict and suppress the occurrence of traffic jams in places where traffic jams are likely to occur.

  In recent years, prediction and suppression of occurrence of traffic jams in so-called sag sections on highways and the like have been performed. As described above, for example, there is a traffic congestion alleviating apparatus disclosed in Patent Document 1 as a technique for predicting or suppressing the occurrence of a traffic jam. This traffic congestion mitigation apparatus creates traffic congestion mitigation information from the average traffic volume and average speed in a predetermined section, and provides the created traffic congestion mitigation information to vehicles traveling in the next section. Moreover, by providing such information, it is possible to promote the appropriate use of each lane and to optimize the vehicle density.

JP 2006-309735 A

  When the occurrence of traffic congestion is predicted by the traffic congestion alleviation apparatus described in Patent Document 1, a decrease in average speed and an increase in average traffic volume are preconditions for traffic congestion. However, even if there is a decrease in average speed or an increase in average traffic, traffic jams do not always occur. For this reason, there has been a problem that it is impossible to accurately predict the occurrence of traffic jams. Furthermore, there is a problem that the occurrence of traffic jams cannot be sufficiently suppressed because the accuracy of forecasting the occurrence of traffic jams is not high.

  Accordingly, an object of the present invention is to provide a traffic jam occurrence prediction device and a traffic jam occurrence suppression device capable of predicting the occurrence of traffic jams with high accuracy and increasing the occurrence of traffic jams by accurately forecasting the occurrence of traffic jams. There is.

  The traffic jam occurrence prediction device according to the present invention that has solved the above problems includes a deceleration propagation ratio calculating means for calculating a deceleration propagation ratio based on a speed decrease amount of a preceding vehicle and a speed decrease amount of a succeeding vehicle, and a deceleration propagation ratio of Predetermined value excess number acquisition means for acquiring the number of times exceeding a predetermined value, and determination of occurrence of traffic congestion that determines that the state is immediately before the occurrence of traffic congestion when the number of times acquired by the predetermined value excess number of times acquisition means exceeds the predetermined number of times And means.

  In the traffic jam occurrence prediction device according to the present invention, the state immediately before the occurrence of traffic jam is determined using the deceleration propagation ratio calculated based on the speed decrease amount of the preceding vehicle and the speed decrease amount of the following vehicle. The phenomenon due to the deceleration propagation ratio corresponds to a traffic jam generation mechanism, and the traffic jam occurs when this mechanism works. Therefore, it is possible to accurately predict the occurrence of traffic jam by observing the deceleration propagation ratio and performing the traffic jam occurrence prediction. At this time, it is conceivable to determine the state immediately before the occurrence of the traffic jam based on whether or not the deceleration propagation ratio exceeds a predetermined value, but since a plurality of deceleration propagation ratios are obtained by the sag part, etc. Setting standards becomes difficult. In this regard, in the traffic jam occurrence prediction device according to the present invention, the number of times the deceleration propagation ratio exceeds a predetermined value is acquired, and when the number of times exceeds the predetermined number, it is determined that the state is immediately before the occurrence of traffic jam. Yes. Accordingly, it is possible to clarify the criteria for determining the state immediately before the occurrence of traffic jams, and to predict the occurrence of traffic jams with high accuracy.

  The traffic jam occurrence suppressing device according to the present invention that has solved the above problems includes the traffic jam occurrence forecasting device, target inter-vehicle distance calculation means for calculating a target inter-vehicle distance at a traffic jam occurrence forecast point, and a target speed at the traffic jam occurrence forecast point. A target speed calculating means for calculating the vehicle speed and an acceleration / deceleration changing means for changing the acceleration / deceleration speed of the vehicle heading to the predicted occurrence point of the traffic jam. In addition, the vehicle heading to the predicted traffic congestion occurrence point is changed to the target inter-vehicle distance calculated by the target inter-vehicle distance calculating means and the target speed calculated by the target speed calculating means.

  In the traffic jam occurrence suppressing device according to the present invention, the target inter-vehicle distance calculated by the target inter-vehicle distance calculation unit with respect to the vehicle heading to the traffic jam occurrence prediction point when the traffic jam occurrence determination unit determines that the traffic jam occurrence immediately preceding state has occurred. Further, the target speed calculated by the target speed calculation means is changed. For this reason, it is possible to increase the effect of suppressing the occurrence of traffic jams by accurately predicting the occurrence of traffic jams.

  Here, it can be set as the aspect provided with the notification means to notify a driver in advance that acceleration / deceleration control is started.

  As described above, by providing notification means for notifying the driver of starting acceleration / deceleration control in advance, the driver can be notified that acceleration / deceleration control is to be started. For this reason, since the acceleration / deceleration of the vehicle can be notified to the driver in advance, the uncomfortable feeling given to the driver when the acceleration / deceleration control is started can be reduced.

  According to the traffic jam occurrence predicting device and the traffic jam occurrence suppressing device according to the present invention, it is possible to accurately predict the occurrence of traffic jams and to increase the traffic jam occurrence suppressing effect by accurately forecasting the occurrence of traffic jams.

It is a block block diagram of the congestion generation suppression apparatus which concerns on embodiment of this invention. It is an image figure for demonstrating the state in which traffic congestion generate | occur | produces in a sag part. It is a graph which shows the time-dependent change of the vehicle speed in the some vehicle in a sag area | region. It is a flowchart which shows the operation | movement procedure in a roadside apparatus. It is a flowchart which shows the operation | movement procedure in a vehicle-mounted apparatus. It is an image figure for demonstrating the driving | running | working state of the vehicle which reaches | attains a sag area | region. It is a graph which shows the time change of the speed of the own vehicle, and the time change of the inter-vehicle distance with a preceding vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a block configuration diagram of a traffic jam occurrence suppressing device according to the present embodiment. As shown in FIG. 1, the congestion occurrence suppressing device according to the present embodiment includes an in-vehicle device 1 mounted on a vehicle and a roadside device 2 provided on the roadside of the road. The in-vehicle device 1 is mounted on a vehicle traveling on a road, and can communicate with the roadside device 2.

  As shown in FIG. 2, it is assumed that a plurality of vehicles Mn (n = 1, 2,...) Are traveling on the road. Furthermore, it is assumed that a roadside communication antenna At is erected at an appropriate position on the road. The vehicle Mn can perform inter-vehicle communication CC with another vehicle traveling on the road. In addition, road-to-vehicle communication C-R is possible with the roadside device 2 via a roadside communication antenna At standing on the side of the road.

  Furthermore, a sag portion SB serving as a traffic jam occurrence prediction point exists on the road. The sag portion SB is a portion where the speed of the vehicle is likely to decrease due to the shape of the road, such as a change point from the downhill to the uphill, and traffic congestion is likely to occur. In the roadside device 2, three sections are set for the sag portion of the road and the upstream side thereof: “inter-vehicle adjustment section FW”, “inter-vehicle adjustment section RW”, and “sag area section SW”. The roadside device 2 predicts the occurrence of traffic jam in the sag portion based on the behavior of the vehicle in the sag area section SW. In addition, the occurrence of traffic congestion is suppressed by controlling the vehicle speed of each vehicle Mn by the in-vehicle device 1 mounted on the vehicle Mn traveling in the pre-interval adjustment interval FW and the inter-vehicle adjustment interval RW.

  The in-vehicle device 1 includes a traffic jam suppression control unit 10. The traffic jam suppression control unit 10 is mainly configured by a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), for example. An inter-vehicle distance sensor 11, a vehicle speed sensor 12, and an in-vehicle communication unit 13 are connected to the traffic jam suppression control unit 10. The traffic jam suppression control unit 10 includes a target vehicle speed / inter-vehicle distance calculation unit 14, an acceleration / deceleration control unit 15, and a notification determination unit 16. Further, an acceleration / deceleration actuator 17 and an information providing device 18 are connected to the traffic jam suppression control unit 10.

  The roadside device 2 includes a roadside communication unit 21, a vehicle speed totaling unit 22, and a deceleration propagation ratio calculation unit 23. Further, the roadside apparatus 2 includes a deceleration propagation ratio threshold value super determination unit 24, a deceleration propagation ratio threshold value super number measurement unit 25, and a deceleration propagation ratio threshold value super number super determination unit 26.

  The inter-vehicle distance sensor 11 in the in-vehicle device 1 includes a radar sensor that detects a vehicle ahead using millimeter waves or the like. The inter-vehicle distance sensor 11 transmits the radar beam forward while scanning the radar beam in the left-right direction, and receives the reflected radar beam. The inter-vehicle distance sensor 11 measures the inter-vehicle distance from the preceding vehicle based on information on each reflection point corresponding to the received radar beam. The inter-vehicle distance sensor 11 outputs inter-vehicle distance information corresponding to the measured inter-vehicle distance to the traffic jam suppression control unit 10 and the in-vehicle communication unit 13.

  The vehicle speed sensor 12 includes, for example, a wheel speed sensor attached to a vehicle wheel. The vehicle speed sensor 12 detects the vehicle speed of the vehicle based on the wheel speed detected by the wheel speed sensor. The vehicle speed sensor 12 outputs vehicle speed information corresponding to the detected vehicle speed to the traffic jam suppression control unit 10 and the in-vehicle communication unit 13.

  The vehicle-mounted communication unit 13 enables vehicle-to-vehicle communication with the vehicle-mounted communication unit 13 mounted on the vehicle-mounted device 1 in another vehicle, and road-vehicle communication with the road-side communication unit 21 in the road-side device 2. Is possible. The in-vehicle communication unit 13 includes the inter-vehicle distance information output from the inter-vehicle distance sensor 11 and the vehicle speed information output from the vehicle speed sensor 12. It transmits to the part 21.

  Furthermore, the vehicle-mounted communication unit 13 is vehicle speed information and inter-vehicle distance information transmitted from the vehicle-mounted communication unit 13 in the vehicle-mounted device 1 mounted on another vehicle, or traffic jam immediately preceding information transmitted from the road-side communication unit 21 in the road-side device 2. Receive. The in-vehicle communication unit 13 outputs the vehicle speed information and the inter-vehicle distance information received from the other vehicle to the traffic jam suppression control unit 10. In addition, when the in-vehicle communication unit 13 acquires the traffic jam occurrence immediately preceding information transmitted from the roadside communication unit 21 in the roadside device 2, the in-vehicle communication unit 13 outputs the acquired traffic jam occurrence immediately preceding information to the traffic jam suppression control unit 10.

  The target vehicle speed / inter-vehicle distance calculation unit 14 in the traffic jam suppression control unit 10 acquires the vehicle speed of the host vehicle based on the vehicle speed information output from the vehicle speed sensor 12. Further, the vehicle speeds of the preceding vehicle and the following vehicle that travel before and after the host vehicle are acquired based on the vehicle speed information acquired from the vehicle before and after being output from the in-vehicle communication unit 13.

  Furthermore, the inter-vehicle distance with the following vehicle is acquired based on the inter-vehicle distance information output from the inter-vehicle distance sensor 11 and the inter-vehicle distance information acquired from the rear vehicle output from the in-vehicle communication unit. Further, based on the information immediately before the occurrence of traffic jam output from the in-vehicle communication unit 13, the presence or absence of occurrence of traffic jam in the sag unit is acquired. Furthermore, the current position information transmitted from the roadside communication unit 21 is acquired.

  The target vehicle speed / inter-vehicle distance calculation unit 14 calculates the target vehicle speed of the host vehicle and the target inter-vehicle distance from the preceding vehicle based on the acquired information. Further, the target vehicle speed / inter-vehicle distance calculation unit 14 outputs target speed information based on the calculated target speed and target inter-vehicle distance information based on the target inter-vehicle distance to the acceleration / deceleration control unit 15.

  The acceleration / deceleration control unit 15 performs acceleration / deceleration control of the host vehicle based on the target vehicle speed information and the target inter-vehicle distance information output from the target vehicle speed / inter-vehicle distance calculation unit 14. For example, when the target vehicle speed is higher than the current vehicle speed and the inter-vehicle distance from the preceding vehicle is large, acceleration control for accelerating the vehicle is performed. Conversely, when the target vehicle speed is smaller than the current vehicle speed and the inter-vehicle distance from the preceding vehicle is small, deceleration control for decelerating the vehicle is performed. The acceleration / deceleration control unit 15 outputs acceleration / deceleration information corresponding to the acceleration / deceleration control to the notification determination unit 16 and the acceleration / deceleration actuator 17.

  The notification determination unit 16 determines the notification content for the driver based on the acceleration / deceleration information output from the acceleration / deceleration control unit 15 and outputs the notification information corresponding to the notification content to the information providing device 18. For example, when acceleration / deceleration control is started, acceleration / deceleration control start information is output to the information providing device 18. Further, when the acceleration / deceleration control is ended, the acceleration / deceleration control end information is output to the information providing device 18.

  The acceleration / deceleration actuator 17 includes a throttle opening adjustment mechanism, a brake operation unit, and the like, and is an actuator that performs acceleration / deceleration control of the vehicle. The acceleration / deceleration actuator 17 performs acceleration / deceleration control of the vehicle based on the acceleration / deceleration information output from the acceleration / deceleration control unit 15. For example, when acceleration information is output, the throttle opening is increased by the throttle opening adjustment mechanism to accelerate the vehicle. When the deceleration information is output, the brake operating unit is operated to decelerate the vehicle.

  The information providing device 18 includes voice information providing means such as a speaker and character information providing means such as a monitor. The information providing device 18 outputs information corresponding to the notification information output from the notification determining unit 16 by using voice information providing means, character information providing means, and the like. For example, when acceleration information is output, a sound such as “accelerate the vehicle” is output, and the characters “acceleration” are displayed on the monitor.

  The roadside communication unit 21 in the roadside device 2 receives vehicle speed information transmitted from the in-vehicle device 1 mounted on each vehicle. The roadside communication unit 21 generates vehicle position information in the order in which the vehicle speed information is received. The roadside communication unit 21 adds the generated vehicle position information to the received vehicle speed information and outputs it to the vehicle speed totaling unit 22.

  Further, when the roadside communication unit 21 acquires the immediately preceding traffic jam occurrence information from the deceleration propagation ratio threshold value super number determination unit 26, the roadside communication unit 21 transmits the acquired traffic jam immediately preceding information to the in-vehicle communication unit 13 in the in-vehicle device 1. Furthermore, the roadside communication unit 21 transmits current position information corresponding to the installation position of the roadside communication antenna At to be transmitted to the in-vehicle communication unit 13 in the in-vehicle device 1 when transmitting the information immediately before the occurrence of the traffic jam. For example, the vehicle travel before section adjustment signal is transmitted to the vehicle traveling in the section before FW adjustment FW. In addition, an inter-vehicle adjustment section travel signal is transmitted to a vehicle traveling in the inter-vehicle adjustment section RW. Furthermore, a sag area travel signal is transmitted to the vehicle traveling in the sag area SW.

  Based on the vehicle speed information output from the roadside communication unit 21, the vehicle speed totaling unit 22 totals the vehicle speeds of the plurality of vehicles and the front-rear relations of the vehicles, and generates vehicle speed totaling result information. The vehicle speed tabulation result information can be expressed, for example, in a vehicle speed change graph as shown in FIG. The vehicle speed totaling unit 22 outputs the generated vehicle speed totaling result information to the deceleration propagation ratio calculating unit 23.

  The deceleration propagation ratio calculation unit 23 calculates speed reduction amounts of a plurality of vehicles based on the vehicle speed total result information output from the vehicle speed total unit 22. Then, the deceleration propagation ratio in the sag region section SW is calculated based on the speed reduction amount of the preceding vehicle and the following vehicle in the sag region section SW among the calculated speed reduction amounts of the plurality of vehicles. The deceleration propagation ratio calculation unit 23 outputs the calculated deceleration propagation ratio in the sag region section SW to the deceleration propagation ratio threshold value super determination unit 24.

  The deceleration propagation ratio threshold value superjudgment unit 24 stores a deceleration propagation ratio threshold value for determining that there is a high possibility that a traffic jam will occur in the sag portion. The deceleration propagation ratio threshold value superjudgment unit 24 compares the stored deceleration propagation ratio threshold value with the deceleration propagation ratio in the sag region output from the deceleration propagation ratio calculation unit 23. Here, when the deceleration propagation ratio in the sag region output from the deceleration propagation ratio calculation unit 23 exceeds the deceleration propagation ratio threshold, the deceleration propagation ratio super information is sent to the deceleration propagation ratio threshold super number measurement unit 25. Output.

  The deceleration propagation ratio threshold super number measurement unit 25 measures the deceleration propagation ratio threshold super number, which is the number of times the deceleration propagation ratio threshold output unit outputs the deceleration propagation ratio information. . The deceleration propagation ratio threshold super number measurement unit 25 outputs the measured deceleration propagation ratio threshold super number super number to the deceleration propagation ratio threshold super number super determination unit 26.

  The deceleration propagation ratio threshold value super number determination unit 26 sets a deceleration propagation ratio threshold value super number setting value for determining that there is a high possibility of occurrence of traffic jam in the sag unit. In the deceleration propagation ratio threshold value super number determination unit 26, the set deceleration propagation ratio threshold value super number setting value and the deceleration propagation ratio threshold value super number measurement unit 25 output from the deceleration propagation ratio threshold value super number measurement unit 25. Are compared with each other, and if the deceleration propagation ratio threshold value exceeding the number exceeds the deceleration propagation ratio threshold value exceeding value, it is determined that it is immediately before the occurrence of the traffic jam. When it is determined that the deceleration propagation ratio threshold value super-number-of-times super-determination unit 26 is immediately before the occurrence of a traffic jam, the information immediately before the traffic jam occurrence is output to the roadside communication unit 21.

  Next, the operation of the congestion occurrence suppressing device according to this embodiment will be described. Here, the operation of the congestion occurrence suppressing device will be described separately for the operation of the roadside device 2 and the operation of the in-vehicle device 1. FIG. 4 is a flowchart showing an operation procedure in the roadside apparatus 2, and FIG. 5 is a flowchart showing an operation procedure in the in-vehicle apparatus 1.

  As shown in FIG. 4, in the roadside device 2 in the traffic jam occurrence suppressing device according to the present embodiment, first, each vehicle Mi (i = 1 to 1) in the sag region by inter-vehicle communication performed with the in-vehicle device 1. The vehicle speed Vi of n) is acquired (S1). Next, based on the acquired vehicle speed Vi of each vehicle, the deceleration propagation ratio calculation unit 23 calculates the deceleration propagation ratio (S2). The deceleration propagation ratio is calculated using the vehicle speed reduction amount of the preceding vehicle and the vehicle speed reduction amount of the following vehicle. Here, the speed reduction amount means an amount of speed that is reduced with respect to the first vehicle when any one of the vehicles traveling in the sag region is the first vehicle. Hereinafter, the calculation method of the deceleration propagation ratio will be described using the vehicle speed change graph shown in FIG. Here, five vehicles from the first vehicle to the fifth vehicle are targeted, and the deceleration propagation ratio between the vehicles is calculated. In this example, the speed reduction amount of the first vehicle is the speed reduction amount of the preceding vehicle, and the speed reduction amount of the second to fifth vehicles is the speed reduction amount of the following vehicle.

  In FIG. 3, the time change of the vehicle speed of a 1st vehicle-a 5th vehicle is each shown in the 1st curve L1-the 5th curve L5, respectively. First, referring to the first curve L1, the vehicle speed of the first vehicle starts to decrease greatly in the sag region, and the vehicle speed at the time when the vehicle speed of the first vehicle becomes the smallest is calculated from the vehicle speed at the time of starting deceleration. Let the difference be ΔVA.

  Further, referring to the first curve L1 and the second curve L2, the difference between the vehicle speed of the first vehicle when the first vehicle starts decelerating and the vehicle speed when the vehicle speed of the second vehicle becomes the smallest is ΔVB. To do. Similarly, referring to the first curve L1 and the third curve L3 to the fifth curve L5, the vehicle speed of the first vehicle and the vehicle speed of the third vehicle to the fifth vehicle at the time when the first vehicle starts decelerating become the smallest. The difference between the vehicle speed and the vehicle speed at this time is ΔVC to ΔVE, respectively. These ΔVA to ΔVE are the speed reduction amounts of the first vehicle to the fifth vehicle, respectively.

  Subsequently, a deceleration propagation ratio Pt (2) from the first vehicle to the second vehicle is calculated. The deceleration propagation ratio is expressed as a ratio between the speed reduction amount of the first vehicle and the speed reduction amount of the nth vehicle. Here, the deceleration propagation ratios Pt (2) to Pt (5) from the second vehicle to the fifth vehicle are expressed by the following equations (1) to (4), respectively.

Pt (2) = ΔVB / ΔVA (1)
Pt (3) = ΔVC / ΔVB (2)
Pt (4) = ΔVD / ΔVC (3)
Pt (5) = ΔVE / ΔVD (4)

  When the deceleration propagation ratio is thus calculated, the deceleration propagation ratio threshold value Pc stored in the deceleration propagation ratio threshold value super-determining unit 24 and the deceleration propagation ratio Pt (i) calculated by the deceleration propagation ratio calculation unit 23 are obtained. The comparison is made sequentially (S3). As the deceleration propagation ratio threshold value Pc, an arbitrary value of 1 or more is set. When the deceleration propagation ratio threshold value Pc exceeds 1, deceleration is amplified and propagated.

  As a result, if it is determined that the deceleration propagation ratio Pt (i) exceeds the deceleration propagation ratio threshold value Pc, the deceleration propagation ratio threshold value super number measurement unit 25 performs the deceleration propagation ratio threshold value super number of times. The deceleration propagation ratio threshold value super number Npc in the measurement unit 25 is incremented (S4). On the other hand, when it is determined that the deceleration propagation ratio Pt (i) is equal to or less than the deceleration propagation ratio threshold value Pc, the deceleration propagation ratio threshold value super number Npc in the deceleration propagation ratio threshold value super number measuring unit 25 is obtained. Is maintained (S5).

  Thereafter, the deceleration propagation ratio threshold value super number determination unit 26 determines that the deceleration propagation ratio threshold value super number measurement unit 25 measures the deceleration propagation ratio threshold value super number of times Npc within a predetermined time T as a deceleration propagation ratio. It is determined whether or not the deceleration propagation ratio threshold excess count setting value Np stored by the threshold excess count determination unit 26 is exceeded (S6).

  Here, the predetermined time T is a time Ls / Vi when the vehicle speed Vi passes through the sag region length Ls. Moreover, the deceleration propagation ratio threshold value supernumerary set value Np is set as follows. The vehicle speed when the vehicle enters the sag area section SW is defined as an approach vehicle speed Vi, and the deceleration amount generated due to a gap between the sag portions is defined as VI. Here, the approach vehicle speed Vi is a vehicle speed when it is assumed that no traffic jam has occurred. At this time, if deceleration propagation occurs once, the vehicle speed decreases by the vehicle speed decrease amount ΔV. The vehicle speed decrease amount ΔV can be expressed by the following equation (5).

  ΔV = VI (Pt (i) −1) (5)

  Here, the vehicle speed at the time of occurrence of traffic congestion is defined as the traffic speed at which traffic congestion occurs Vj. This congestion occurrence vehicle speed Vj is a speed statistic value as a vehicle speed at the time of congestion. At this time, the vehicle speed Vi at the time of non-congested traffic decreases to the traffic jam generating vehicle speed Vj when deceleration propagation occurs (Vi−Vj) / ΔV times within a predetermined time T. Therefore, the deceleration propagation ratio threshold excess number set value Np is set to (Vi−Vj) / VI (Pt (i) −1) times within the predetermined time T.

  Note that the deceleration amount VI is an amount by which the preceding vehicle preceding the own vehicle decelerates due to a gap between the vehicles from the steady running state, and the vehicle speed decrease amount ΔV is the difference between the deceleration amount of the preceding vehicle and the deceleration amount of the own vehicle. . For this reason, assuming that the deceleration propagation ratio Pt (i) is larger than 1 and constant, the product of the number of times of deceleration propagation and the vehicle speed reduction amount ΔV is the overall speed reduction amount.

  For example, assuming that the vehicle speed Vi = 80 km / h, the traffic speed Vj = 30 km / h, the deceleration amount VI = 7 km / h, and the deceleration propagation ratio Pt (i) = 1.3, the deceleration propagation ratio threshold value super number setting value Np = (80-30) / 7 (1.3-1) ≈24.

  As a result of the determination in step S6, if it is determined that the deceleration propagation ratio threshold value exceeding number Npc measured within the predetermined time T exceeds the deceleration propagation ratio threshold value exceeding number setting value Np, immediately before the occurrence of the traffic jam The flag SJ is set (SJ = 1) (S7). On the other hand, if it is determined that the deceleration propagation ratio threshold excess count Npc measured within the predetermined time T is equal to or less than the deceleration propagation ratio threshold excess count set value Np, the traffic jam occurrence immediately preceding flag SJ is cleared (SJ = 0) (S8). Thereafter, a traffic jam occurrence immediately preceding flag SJ is transmitted to the in-vehicle device 1 via the roadside communication unit 21 (S9). In this way, the process in the roadside apparatus 2 is complete | finished.

  As described above, the deceleration propagation ratio threshold super number Npc, which is the number of times the deceleration propagation ratio Pt (i) exceeds the deceleration propagation ratio threshold value Pc, exceeds the deceleration propagation ratio threshold super number setting value Np. If it is determined, the setting of the reference for determining the state immediately before the occurrence of traffic jam can be made clear by setting the flag SJ immediately before the occurrence of traffic jam. Accordingly, it is possible to clarify the criteria for determining the state immediately before the occurrence of traffic jams, and to predict the occurrence of traffic jams with high accuracy.

  For example, a case where the occurrence of traffic congestion is predicted by observing the average traffic volume and the average vehicle speed is compared with a case where the occurrence of traffic congestion is predicted by observing the deceleration propagation ratio as in the present embodiment. In this case, a decrease in average speed and an increase in average traffic volume are preconditions for the occurrence of traffic congestion. For this reason, even if the precondition is satisfied, the traffic jam does not necessarily occur.

  On the other hand, the phenomenon caused by the deceleration propagation ratio corresponds to a traffic jam generation mechanism, and traffic jam occurs when this mechanism works. Therefore, it is possible to accurately predict the occurrence of traffic jam by observing the deceleration propagation ratio and performing the traffic jam occurrence prediction.

  Next, processing in the in-vehicle device 1 will be described. As shown in FIG. 5, the in-vehicle device 1 acquires various data such as the distance L to the sag region, the vehicle speed of the host vehicle, and the inter-vehicle distance from the preceding vehicle (S11). Among these various data, the distance L to the sag region is acquired from the current position information transmitted from the roadside device 2 by road-to-vehicle communication. Further, the vehicle speed of the host vehicle is acquired from the vehicle speed information output from the vehicle speed sensor 12. Further, the inter-vehicle distance of the preceding vehicle is acquired from the inter-vehicle distance information output from the inter-vehicle distance sensor 11. On the other hand, these pieces of information are also supplementarily acquired by information received from the vehicle-to-vehicle communication or the road-to-vehicle communication received via the in-vehicle communication unit 13.

  If various data are acquired, it will be judged whether the distance L to a sag area | region is below the predetermined distance setting value Lj (S12). The distance setting value Lj here is set to a range that is subject to traffic jam occurrence prediction from the sag area. This distance setting value Lj is set to the distance from the sag portion to the position immediately before entering the inter-vehicle distance adjustment section RW shown in FIG.

  As a result of the determination in step S12, when it is determined that the distance L to the sag area is not less than the predetermined distance setting value Lj, the process in step S12 is repeated. On the other hand, if it is determined that the distance L to the sag area is equal to or less than the predetermined distance setting value Lj, the infrastructure data transmitted from the roadside device 2 by road-to-vehicle communication is acquired (S13). Here, the infrastructure data includes a traffic jam immediately preceding flag SJ.

  It is determined whether or not the traffic jam occurrence immediately preceding flag SJ included in the infrastructure data is set (S14). As a result, when the traffic jam immediately before flag SJ is not set (SJ = 0), the process returns to step S13 and the acquisition of infrastructure data is repeated. On the other hand, if it is determined that the traffic jam immediately before flag SJ is set (S = 1), the travel section in which the host vehicle is currently traveling is determined (S15).

  As a result, when the currently traveling section is the pre-adjustment section FW, the target vehicle speed / inter-vehicle distance calculation unit 14 determines the target vehicle speed Vm and the target inter-vehicle distance at which the vehicle density in the sag portion becomes the target vehicle density qm. Lm is calculated (S16). The procedure for calculating the target vehicle speed Vm and the target inter-vehicle distance Lm will be described later. While the target vehicle speed Vm and the target inter-vehicle distance Lm are being calculated, control is performed such that the vehicle travels while maintaining the travel lane (S16).

  Further, when the currently traveling section is the inter-vehicle distance adjustment section RW, the vehicle is added so as to achieve the target vehicle speed Vm and the target inter-vehicle distance Lm calculated when traveling in the pre-inter-vehicle distance adjustment section FW. Deceleration control is performed (S17). When performing acceleration / deceleration control, the target vehicle speed / inter-vehicle distance calculation unit 14 outputs target speed information and target inter-vehicle distance information to the acceleration / deceleration control unit 15. The acceleration / deceleration control unit 15 performs acceleration / deceleration control based on the target vehicle speed information and the target inter-vehicle distance information output from the target vehicle speed / inter-vehicle distance calculation unit 14. Therefore, the acceleration / deceleration control unit 15 outputs acceleration / deceleration information corresponding to the acceleration / deceleration control to the acceleration / deceleration actuator 17. Further, when the currently traveling section is within the sag region section SW, control is performed to maintain the target vehicle speed Vm and the target inter-vehicle distance Lm (S18). Thus, control is performed to maintain the target vehicle speed Vm and the target inter-vehicle distance Lm until the vehicle passes through the sag region.

  Here, the calculation procedure (S16) of the target vehicle speed and the target inter-vehicle distance will be described. Here, after describing the pre-vehicle distance adjustment section FW and the inter-vehicle distance adjustment section RW, the calculation procedure of the target vehicle speed and the target inter-vehicle distance will be described. Now, when the infrastructure data including the traffic jam immediately before flag SJ is transmitted to the in-vehicle device 1 of the vehicle traveling in the pre-adjustment section FW shown in FIG. 2, the target vehicle speed and inter-vehicle distance calculation in the in-vehicle device 1 is performed. The unit 14 first calculates the necessary adjustment distance La1 shown in FIG. The length of the adjustment necessary distance La1 is the same as the length of the inter-vehicle adjustment section RW shown in FIG. Further, the necessary adjustment distance La1 here is a distance obtained by adding a predetermined width to the necessary distance R shown in FIG. Next, a transmission correspondence distance Lc, which is a distance corresponding to the time required to transmit the contents of acceleration / deceleration control to be executed later to the driver, is calculated. The sum of the necessary adjustment distance La1 and the transmission corresponding distance Lc is the distance setting value Lj.

  For example, it is assumed that road-to-vehicle communication and vehicle-to-vehicle communication / calculation processing are performed twice for 10 seconds. Further, assuming that the vehicle speed Vi of the host vehicle is 80 km / h, the transmission correspondence distance Lc can be set to 450 m or more by the following equation (6).

  Lc = 80 / 3.6 × 20 = 444≈450 (m) (6)

  Further, the current vehicle speed Vi is 80 km / h, the vehicle speed Vi2 obtained by subtracting the deceleration amount for achieving the target inter-vehicle time tm from the current vehicle speed Vi is 70 km / h, the target vehicle speed Vm = 80 km / h, and the usable deceleration Gm. Is 0.1 G, the current inter-vehicle time tc is 1.5 s, the target inter-vehicle time tm is 2.5 s, and the inter-vehicle time is increased by 1 second, the required distance R is calculated as 216.4≈220 m. By providing the necessary distance R with a predetermined width, the necessary adjustment distance La1 can be set to 220 m or more.

  Therefore, for example, the section FW before inter-vehicle adjustment can be set from the first point α1 that is about 5 km before the sag SB to the second point α2 that is 2 to 3 km before the sag SB. Further, the sag region, for example, the third point α3 that is the gradient reduction start point when the sag part is the bottom can be set as the inter-vehicle distance adjustment section RW.

  Next, the target vehicle speed Vm and the target inter-vehicle distance Lm will be described. Now, it is assumed that the vehicle density is equal to or higher than the vehicle density qs where traffic is likely to occur. The target vehicle density qm in this case is set. The target vehicle density qm can be calculated by the following equation (7) by multiplying the vehicle density qs with high possibility of occurrence of traffic congestion by a predetermined constant k (0 <k <1).

  Lm = 1000 / qm (7)

  Here, since 1000 (m) / Lm = qm, the target inter-vehicle distance Lm can be expressed as 1000 / qm. Further, since the target inter-vehicle distance Lm = Vm × tm can be expressed using the target inter-vehicle time tm, the following equation (8) is established.

  Vm = (1000 / (qm × tm)) (8)

  By using the expressions (7) and (8), the target inter-vehicle distance Lm and the target vehicle speed Vm can be calculated. As a specific example, when the constant k = 0.7, the vehicle density qs = 25, and the target inter-vehicle time tm = 2.5, the target vehicle density qm = 25 × 0.7 = 17.5. Therefore, the target inter-vehicle distance Lm = 1000 / 17.5 = 57 (m). Further, the target vehicle speed Vm = 1000 / (17.5 × 2.5) = 22.8 (m / s) = 82 (km / h).

  Further, when performing any one of the controls of S16 to S18, the notification determination unit 16 starts acceleration / deceleration control to be output to the information providing device 18 based on the acceleration / deceleration information provided from the acceleration / deceleration control unit 15. Information is generated and output to the information providing apparatus 18. The information providing device 18 provides information to the driver based on the acceleration / deceleration control start information output from the notification determination unit 16. By providing information to the driver in this way, it is possible to notify the driver that acceleration / deceleration control is to be started. For this reason, since the acceleration / deceleration of the vehicle can be notified to the driver in advance, the uncomfortable feeling given to the driver when the acceleration / deceleration control is started can be reduced.

The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above embodiment, the roadside device 2 performs traffic jam prediction. However, the vehicle-mounted device may be provided with a deceleration propagation ratio calculation unit or the like, and the vehicle-mounted device may perform traffic jam prediction.
In the above-described embodiment, the congestion control is performed for each vehicle in the in-vehicle device. For example, the target vehicle speed or the target inter-vehicle distance for suppressing the congestion is calculated by the roadside device and transmitted to the in-vehicle device to suppress the congestion. It can also be set as the aspect which controls. Alternatively, the target vehicle speed and the target inter-vehicle distance of a plurality of vehicles can be calculated with one vehicle, and the target vehicle speed and the target inter-vehicle distance can be transmitted to each vehicle by inter-vehicle communication. In the above-described embodiment, the deceleration propagation ratio threshold value super-number setting value Np is calculated using the deceleration propagation ratio Pt (i), the vehicle speed Vi, and the traffic jam occurrence vehicle speed Vj. The number setting value Np may be set as a constant for each sag portion, for example.

  DESCRIPTION OF SYMBOLS 1 ... In-vehicle apparatus, 2 ... Roadside apparatus, 10 ... Congestion suppression control part, 11 ... Inter-vehicle distance sensor, 12 ... Vehicle speed sensor, 13 ... In-vehicle communication part, 14 ... Target vehicle speed / inter-vehicle distance calculation part, 15 ... Acceleration / deceleration control part , 16 ... Notification determination unit, 17 ... Acceleration / deceleration actuator, 18 ... Information providing device, 21 ... Roadside communication unit, 22 ... Vehicle speed totaling unit, 23 ... Deceleration propagation ratio calculation unit, 24 ... Deceleration propagation ratio threshold value super determination unit 25 ... Deceleration propagation ratio threshold value super number measurement unit, 26 ... Deceleration propagation ratio threshold value super number determination unit, At ... Road side communication antenna, FW ... Pre-inter-vehicle adjustment section, RW ... Inter-vehicle adjustment section, SW ... Sag area section, SB ... sag portion, La1 ... adjustable distance, Lc ... transmission correspondence distance, Lj ... distance setting value, Ls ... sag area length, α1 ... first point, α2 ... second point, α3 ... third point.

Claims (3)

A deceleration propagation ratio calculating means for calculating a deceleration propagation ratio based on the speed decrease amount of the preceding vehicle and the speed decrease amount of the following vehicle;
A predetermined value super number acquisition means for acquiring the number of times the deceleration propagation ratio exceeds a predetermined value;
A traffic jam occurrence determining means for determining that the number of times acquired by the predetermined value number of times acquisition means exceeds a predetermined number of times, immediately before the occurrence of the traffic jam;
A device for predicting occurrence of traffic congestion, comprising: The traffic jam occurrence prediction device according to claim 1,
A target inter-vehicle distance calculating means for calculating a target inter-vehicle distance at a traffic jam predicted point;
Target speed calculating means for calculating a target speed at the traffic jam occurrence prediction point;
An acceleration / deceleration changing means for changing the acceleration / deceleration of the vehicle heading to the predicted occurrence point of the traffic jam,
The acceleration / deceleration changing means, when the congestion occurrence determining means determines that the state is immediately before the occurrence of the congestion, for the vehicle heading to the predicted occurrence position of the congestion, the target inter-vehicle distance calculated by the target inter-vehicle distance calculating means and the A traffic jam occurrence suppressing device for changing to the target speed calculated by the target speed calculating means.   The congestion occurrence suppressing device according to claim 2, further comprising notification means for notifying a driver in advance that the acceleration / deceleration control is started.

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