JP2019153342A - Congestion determination device - Google Patents

Abstract

To provide congestion information by using a road link in ordinary map data without using a dedicated link.SOLUTION: A congestion determination device detects a low speed section in which mobile bodies move at a predetermined speed or less, based on a speed of the mobile bodies such as vehicles, and determines whether the low speed section is longer than a predetermined distance and determines that the low speed section longer than the predetermined distance is a congestion section. In a case of the low speed section shorter than the predetermined distance, it may be caused by, for example, a wait at a stoplight, a temporary stop, or the like with no congestion actually generated, accordingly exclusion thereof improves accuracy in congestion determination.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a technique for providing traffic jam information.

  A traffic information providing service by VICS (Vehicle Information and Communication System: registered trademark) is known. VICS traffic information is provided in units of dedicated link data called VICS links. In general, a VICS link is configured in units of links longer than road links that constitute normal map data. Therefore, the navigation device stores in advance correspondence information between the VICS link number and the road section corresponding to the VICS link of the VICS link number, and the road corresponding to the received traffic information based on the stored correspondence information. The section is calculated (see Patent Document 1).

Japanese Patent Laying-Open No. 2005-214784 (paragraphs 0004 to 0005)

  In the above method, it is necessary to create a dedicated link for providing traffic information, which takes time and cost to create. In addition, a storage capacity for holding information related to the dedicated link is required for both the server on the transmission side and the navigation device on the reception side.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide traffic jam information using a road link of normal map data without using a dedicated link.

  The invention according to the claim is a traffic congestion determination device that detects a low speed section in which the moving body is moving at a predetermined speed or less based on speed acquisition means for acquiring the speed of the moving body and the acquired speed. A low speed section detecting means for determining whether or not the low speed section is longer than a predetermined distance, and determining means for determining a low speed section longer than the predetermined distance as a traffic jam section.

  The invention described in another claim is a traffic congestion determination method executed by a server device, wherein a speed acquisition step of acquiring the speed of a mobile body, and the mobile body is below a predetermined speed based on the acquired speed. A low-speed section detecting step for detecting a moving low-speed section, and a determination step for determining whether the low-speed section is longer than a predetermined distance and determining a low-speed section longer than the predetermined distance as a traffic jam section. It is characterized by.

  The invention described in another claim is a traffic jam determination program executed by a server device including a computer, wherein a speed acquisition unit that acquires the speed of the mobile body, and the mobile body has a predetermined speed based on the acquired speed. The computer as a low speed section detecting means for detecting a low speed section moving below, a determination means for determining whether the low speed section is longer than a predetermined distance, and determining a low speed section longer than the predetermined distance as a traffic jam section Is made to function.

  The invention described in another claim is a terminal device capable of communicating with a server device, request means for requesting traffic information from the server device, longer than a predetermined distance, and the moving body moves at a predetermined speed or less. Receiving means for receiving traffic information from the server device, and display means for displaying information indicating that the traffic jam section is congested on a display unit. And

  The invention described in another claim is a traffic jam information display method executed by a terminal device capable of communicating with a server device, a request step for requesting the traffic information to the server device, longer than a predetermined distance, and A reception process for receiving traffic information from the server device that determines that a section in which a moving body is moving at a predetermined speed or less is a traffic congestion section, and a display for displaying information indicating that the traffic congestion section is congested on the display unit And a process.

  The invention described in another claim is a traffic information display program that is communicable with a server device and is executed by a terminal device including a computer, requesting means for requesting traffic information from the server device, a predetermined distance Receiving means for receiving traffic information from the server device, which is determined to be a traffic congestion section that is long and moving at a predetermined speed or less, and information indicating that the traffic congestion section is congested on the display unit The computer is caused to function as display means for displaying.

The structure of the traffic information provision system which concerns on an Example is shown. 1 shows a schematic configuration of a server. 1 shows a schematic configuration of a navigation device. It is a figure explaining the problem of a short road link. It is a flowchart of a travel history data recording process. It is a flowchart of a travel history data transmission process. It is explanatory drawing of the 1st congestion degree determination method. It is a flowchart of the determination process by the 1st congestion degree determination method. It is explanatory drawing of the 2nd congestion degree determination method. It is a flowchart of the determination process by the 2nd congestion degree determination method. It is a flowchart of traffic information transmission processing.

  In a preferred embodiment of the present invention, the traffic congestion determination device detects a low speed section in which the moving body is moving at a predetermined speed or less based on speed acquisition means for acquiring the speed of the moving body and the acquired speed. Low-speed section detection means, and determination means for determining whether or not the low-speed section is longer than a predetermined distance, and determining the low-speed section longer than the predetermined distance as a traffic jam section.

  The traffic jam determination device detects a low speed section in which the moving body is moving at a predetermined speed or less based on the speed of the moving body such as a vehicle. Then, it is determined whether or not the low speed section is longer than the predetermined distance, and the low speed section longer than the predetermined distance is determined as the congestion section. In the low speed section shorter than the predetermined distance, there is a case where there is actually no traffic jam such as waiting for a signal or a temporary stop, for example. By excluding these, it is possible to improve the accuracy of the traffic jam judgment.

  In one aspect of the traffic jam determination device, the speed acquisition unit acquires the speed of the moving body for each point where the moving body travels, and the low speed section detection unit has the speed of the moving body equal to or less than the predetermined speed. A section formed by connecting a plurality of consecutive points is detected as the low speed section. In this aspect, a low speed section is detected by connecting a plurality of continuous travel points where the speed of the moving body is equal to or lower than a predetermined speed.

  In another aspect of the traffic congestion determination apparatus, the speed acquisition unit acquires an average speed of the moving body for each section in which the moving body travels, and the low speed section detection unit determines that the average speed of the moving body is the predetermined speed. A section that is lower than the speed is detected as the low speed section. In this aspect, the low speed section is detected based on the average speed for each travel section of the moving body.

  In this aspect, the low speed section detection unit generates a combined section by combining adjacent sections before and after when the determination unit determines that the detected low speed section is shorter than the predetermined distance. When the average speed of the moving body in the section is equal to or lower than the predetermined speed, the combined section is detected as the low speed section. Thereby, the determination of a traffic jam section is performed for a low speed section longer than a predetermined distance. In a preferred example, the section is a road link constituting map data.

  Another aspect of the traffic jam determination device includes a registration unit that associates information indicating that there is a traffic jam with a road corresponding to the traffic jam section and stores the information in a storage unit. In this aspect, information indicating that there is a traffic jam is stored in association with the determined traffic jam section.

In another preferred embodiment of the present invention, the congestion determination method executed by the server device includes a speed acquisition step of acquiring the speed of the moving body, and the moving body moves at a predetermined speed or less based on the acquired speed. A low speed section detecting step for detecting a low speed section, determining whether the low speed section is longer than a predetermined distance, and determining a low speed section longer than the predetermined distance as a traffic jam section;
Is provided. Also by this method, it is possible to improve the accuracy of traffic jam determination by excluding a low speed section shorter than a predetermined distance.

  In another preferred embodiment of the present invention, a traffic jam determination program executed by a server device including a computer includes speed acquisition means for acquiring the speed of the mobile object, and the mobile object is equal to or less than a predetermined speed based on the acquired speed. The computer as a low speed section detecting means for detecting a low speed section that is moving at, a determination means for determining whether the low speed section is longer than a predetermined distance, and determining a low speed section longer than the predetermined distance as a traffic jam section. Make it work. By executing this program on a computer, the above-described congestion determination device can be realized.

  In another preferred embodiment of the present invention, the terminal device capable of communicating with the server device includes request means for requesting traffic information from the server device, a longer distance than the predetermined distance, and the moving body moves at a predetermined speed or less. Receiving means for receiving traffic information that determines that the current traffic section is a traffic jam section from the server device, and display means for displaying information indicating that the traffic jam section is congested on a display unit.

  The terminal device requests traffic information from the server device. And the traffic information which determined that the area which is longer than the predetermined distance and the moving body is moving below the predetermined speed is the traffic jam section is received from the server device. And a terminal device displays the information which shows that the congestion area is congested on a display part. Thereby, traffic jam information can be displayed on the terminal device.

  In another preferred embodiment of the present invention, a traffic jam information display method executed by a terminal device capable of communicating with a server device includes a requesting step for requesting traffic information from the server device, and a moving body moving at a predetermined speed or less. A receiving step for receiving information on a traffic jam section that is a section that is longer than a predetermined distance from the server device, and a display for displaying information indicating that the traffic jam section is congested on a display unit A process. With this method, it is possible to display traffic jam information on the terminal device.

  In another preferred embodiment of the present invention, a traffic jam information display program that is communicable with a server device and executed by a terminal device including a computer is a request unit that requests traffic information from the server device. Receiving means for receiving from the server device information on a traffic jam section that is a section moving at a speed or less and that is longer than a predetermined distance, and information indicating that the traffic jam section is congested on the display unit The computer is caused to function as display means for displaying. The above terminal device can be realized by executing this program on a computer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Device configuration]
(overall structure)
FIG. 1 shows a schematic configuration of a traffic jam information providing system according to an embodiment. The traffic jam information providing system includes a server 7 and a plurality of navigation devices 1. The navigation device 1 can transmit and receive data to and from the server 7 by wireless communication.

(server)
FIG. 2 shows a schematic configuration of the server 7. The server 7 is a computer device, and includes a communication unit 71, a control unit (CPU) 72, a ROM 73, a RAM 74, a map database (hereinafter referred to as “DB”) 75, a travel history DB 76, And a traffic jam information DB 77.

  The communication unit 71 transmits and receives data to and from the navigation device 1 by wireless communication. The control unit 72 controls the entire server 7. The ROM 73 stores a program executed by the server 7 and the like. The RAM 74 functions as a work memory when the server 7 performs various processes.

  The map DB 75 stores road map data. The road map data indicates a road network by intersection nodes and road links. “Intersection node” indicates a point corresponding to the intersection, and “road link” indicates a road connecting the intersections. In the present embodiment, the traffic jam information is provided by using the road links constituting the road map data.

  The travel history DB 76 stores travel history data of the vehicle on which the navigation device 1 is mounted. Specifically, the navigation device 1 measures various information such as the current position of the vehicle, the traveling direction (up / down), time, and speed while the vehicle is traveling at regular time intervals or constant travel distances. . When a predetermined transmission timing arrives while the vehicle is traveling, the traveling history data of the vehicle is transmitted to the server 7. The server 7 receives the travel history data from the plurality of navigation devices 1 and stores it in the travel history DB 76. The navigation device 1 transmits, for example, time, vehicle position, traveling direction (up / down), traveling speed, and the like as traveling history data to the server 7.

  The traffic jam information DB 77 stores information indicating the presence or absence of traffic jams, specifically the traffic jam level, in association with the road link. Note that the degree of congestion is classified into three categories: “smooth”, “congested”, and “congested”.

  In the above configuration, the control unit 72 is an example of the speed acquisition unit, the low speed section detection unit, the determination unit, and the registration unit of the present invention, and the traffic jam information DB 77 is an example of the storage unit of the present invention.

(Navigation device)
FIG. 3 shows the configuration of the navigation device 1. As shown in FIG. 3, the navigation device 1 includes a self-supporting positioning device 10, a GPS receiver 18, a system controller 20, a disk drive 31, a data storage unit 36, a communication interface 37, a communication device 38, a display unit 40, a voice output. A unit 50 and an input device 60 are provided.

  The system controller 20, disk drive 31, data storage unit 36, communication interface 37, display unit 40, audio output unit 50, and input device 60 are connected to each other via the bus line 30.

  The autonomous positioning device 10 includes an acceleration sensor 11, an angular velocity sensor 12, and a distance sensor 13. The acceleration sensor 11 is made of, for example, a piezoelectric element, detects vehicle acceleration, and outputs acceleration data. The angular velocity sensor 12 is composed of, for example, a vibrating gyroscope, detects the angular velocity of the vehicle when the direction of the vehicle is changed, and outputs angular velocity data and relative azimuth data. The distance sensor 13 measures a vehicle speed pulse composed of a pulse signal generated with the rotation of the vehicle wheel.

  The GPS receiver 18 receives radio waves 19 carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data is used to detect the absolute position of the vehicle (hereinafter also referred to as “current position”) from latitude and longitude information.

  The system controller 20 includes an interface 21, a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 23, and a RAM (Random Access Memory) 24, and controls the entire navigation apparatus 1.

  The interface 21 performs interface operations with the acceleration sensor 11, the angular velocity sensor 12, the distance sensor 13, and the GPS receiver 18. From these, vehicle speed pulses, acceleration data, relative azimuth data, angular velocity data, GPS positioning data, absolute azimuth data, and the like are input to the system controller 20.

  The CPU 22 controls the entire system controller 20. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22.

  The disk drive 31 reads music and video data from a CD, DVD, etc. (not shown) and outputs them to the display unit 40 and the audio output unit 50.

  The data storage unit 36 is composed of, for example, an HDD and stores various data used for navigation processing such as map data. The communication device 38 performs wireless communication with the server 7 via the network. The communication device 38 may be a dedicated wireless communication unit built in the navigation device 1, and is a unit that connects to a mobile phone by wire or wirelessly and connects to a network using the communication function of the mobile phone. There may be.

  The display unit 40 displays various display data on a display device such as a display under the control of the system controller 20. Specifically, the system controller 20 reads map data from the data storage unit 36. The display unit 40 displays the map data read from the data storage unit 36 by the system controller 20 on the display screen. The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30 and a memory such as a VRAM (Video RAM), and can display image information that can be displayed immediately. A buffer memory 42 that temporarily stores, a display control unit 43 that controls display of a display 44 such as a liquid crystal display or a CRT (Cathode Ray Tube) based on image data output from the graphic controller 41, and a display 44 are provided. . The display 44 functions as an image display unit, and includes, for example, a liquid crystal display device having a diagonal size of about 5 to 10 inches and is mounted near the front panel in the vehicle.

  The audio output unit 50 is a D / A converter 51 that performs D / A (Digital to Analog) conversion of audio digital data sent from the disk drive 31 or the RAM 24 via the bus line 30 under the control of the system controller 20. , An amplifier (AMP) 52 that amplifies the audio analog signal output from the D / A converter 51, and a speaker 53 that converts the amplified audio analog signal into sound and outputs the sound into the vehicle.

  The input device 60 includes keys, switches, buttons, a remote controller, a voice input device, and the like for inputting various commands and data. The input device 60 is disposed around the front panel and the display 44 of the main body of the in-vehicle electronic system mounted in the vehicle. When the display 44 is a touch panel system, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

  In the above configuration, the CPU 22 is an example of a request unit of the present invention, the communication device 38 is an example of a reception unit of the present invention, and the display unit 40 is an example of a display unit of the present invention.

[How to provide traffic information]
Next, a traffic jam information providing method performed between the navigation device 1 and the server 7 will be described.

(Short road link problem)
As described above, in the present embodiment, the degree of traffic jam is determined in units of road links, and traffic jam information is provided. In this case, since the road link corresponds to a road in an actual road network, there is a road link with a short link length (hereinafter also referred to as “link length”). Here, there are the following problems when determining the degree of congestion for a short road link.

(1) Sufficient acceleration is not performed on the road.
This state is shown in FIG. As shown in the figure, it is assumed that the three road links A to C are continuous, and the vehicle 5 at the tip of the link A stops at a red signal. When the signal turns blue, the vehicle 5 starts and accelerates. However, since the link B is short, the vehicle 5 exits the link B in the middle of acceleration and reaches the link C. That is, in the link B, the vehicle 5 cannot be accelerated sufficiently yet and the vehicle speed does not sufficiently increase, so that both the maximum speed and the average speed are lowered. Therefore, if the degree of congestion of the link B is determined based on the vehicle speed during acceleration, the link B may be erroneously determined as a congestion or congestion even though the link B is not actually congested.

(2) The length of a congested vehicle train is less than the length that can be determined as a traffic jam.
This situation is shown in FIG. As shown in the figure, since there are two stop vehicles 5a and 5b in the link B and occupy the entire road length of the link B, the link B is determined to be congested according to the normal congestion degree determination. . However, in reality, two vehicles can escape to link C with a single green light. Further, even from the driver of the second vehicle 5b, which is the last part of the vehicle train, there is only one vehicle 5a in the front, and it does not appear that a vehicle train is formed in the front. Therefore. It is not appropriate to judge this situation as a traffic jam.

  Generally, in order to be recognized as a traffic jam, it is necessary to configure a plurality of stationary or low-speed trains. However, if the link length of the road is short, a sufficiently long lane is not constructed on the road, and it cannot be distinguished from traffic jams or traffic conditions other than traffic jams (waiting for traffic lights, pauses, etc.). The reliability of information is impaired.

  From the above viewpoint, the present embodiment provides a congestion degree determination method that does not cause the above-described problems even when the link length is short. Hereinafter, each process is demonstrated in order.

(Collecting driving history data)
First, collection of vehicle travel history data will be described. FIG. 5 is a flowchart of the travel history data recording process. The travel history data recording process is a process in which the navigation device 1 collects the travel history data of the vehicle and stores it inside. This process is executed by the navigation device 1 mounted on the vehicle, specifically, the CPU 22.

  First, the CPU 22 acquires information from the various sensors of the self-supporting positioning device 10 and the GPS receiver 18 (step S11), determines the current position, and matches the road link (S12). As a result, the CPU 22 acquires information such as the current position of the vehicle, the traveling direction (up / down), and the road link that is currently traveling, and stores it in the data storage unit 36 or the RAM 24 as traveling history data in association with the time. (Step S13).

  Then, the CPU 22 determines whether or not the vehicle has stopped (step SS14). Usually, during the traveling of the vehicle, the collection of travel history data is repeatedly performed at regular time intervals or constant travel distances, so the processing returns to step S11. On the other hand, when the vehicle stops (step S14: Yes) and collection of travel history data becomes unnecessary, the CPU 22 ends the process.

  FIG. 6 is a flowchart of the travel history data transmission process. The travel history data transmission process is a process of transmitting travel history data from the navigation device 1 to the server 7.

  First, the navigation apparatus 1 acquires the output of various sensors and time information (step S21), and determines whether or not the transmission timing of travel history data has arrived (step S22). For example, when traveling history data is transmitted to the server 7 at regular time intervals, the navigation device 1 determines whether or not a certain time has elapsed. Further, when the travel history data is transmitted to the server 7 for each predetermined travel distance, the navigation device 1 determines whether or not the travel distance has traveled.

  When the transmission timing has arrived (step S22: Yes), the navigation device 1 transmits the travel history data stored by the travel history data recording process described above to the server 7 (step S23). And the navigation apparatus 1 determines whether the vehicle stopped (step S24). If the vehicle is not stopped (step S24: No), the process returns to step S21, and transmission of travel history data is repeated each time the transmission timing arrives. On the other hand, when the vehicle stops (step S24: Yes), the process ends.

  On the other hand, the server 7 receives the travel history data from the navigation device 1 (step S25) and stores it in the travel history DB 76 (step S26). Then, the process ends. Thus, the travel history data is transmitted from the navigation device 1 to the server 7 and accumulated in the travel history DB 76. The server 7 can accumulate travel history data of a plurality of vehicles by receiving travel history data from the plurality of navigation devices 1.

(First method for determining the degree of congestion)
Next, the first congestion degree determination method will be described. The first congestion degree determination method is a method of taking out a low speed section having a sufficient length from continuous low speed travel coordinates. This will be described in detail below.

  FIG. 7 is a diagram for explaining a first congestion degree determination method. The server 7 acquires a plurality of travel coordinates and the vehicle speed (vehicle speed) at the travel coordinates from the travel history DB 76. Here, the “traveling coordinates” are coordinates indicating a traveling point of the vehicle, and correspond to position coordinates included in the traveling history data. When the vehicle speed at each travel point is included in the travel history data, the server 7 may set the vehicle speed as the speed of the travel coordinates. In addition, when the vehicle speed is not included in the travel history data, the server 7 may calculate the vehicle speed at each travel coordinate based on the time and interval (distance) of the continuous travel coordinates.

  As shown in FIG. 7, the server 7 arranges a plurality of travel coordinates on the road link. At that time, the server 7 classifies the vehicle speed into three categories of “high speed”, “slightly low speed (medium speed)”, and “low speed”. Next, the server 7 extracts a section in which travel coordinates of “slightly low speed” and “low speed” (these are collectively referred to as “low speed zone”) from a plurality of travel coordinates arranged on the road link. Then, traveling coordinates in the low speed zone are connected to form a “low speed section”. This low speed section is a section where it is estimated that a vehicle train will be formed because the speed of the vehicle is slightly low or low.

  Next, the server 7 determines whether or not the length of the low speed section is longer than a predetermined distance (length). If the low speed section is longer than the predetermined distance, it is considered that a long train is formed over the section, and therefore the server 7 determines that the low speed section is congested. On the other hand, when the length of the low speed section is shorter than the predetermined distance, the formed train row is considered to be short. In this case, as described above, there is a possibility that a short vehicle train is formed due to a cause such as waiting for a signal or a temporary stop, and a traffic jam does not always occur. Therefore, when the length of the low speed section is shorter than the predetermined distance, the server 7 does not determine that the low speed section is a traffic jam. Thereby, the erroneous determination when the road link as described with reference to FIG. 4 is short can be prevented. Note that the “predetermined distance” in this case is a distance corresponding to the length of a vehicle train that is generally recognized as a traffic jam, and may be, for example, 50 m or more.

  FIG. 8 is a flowchart of the determination process by the first congestion degree determination method. This process is performed by the control unit 72 of the server 7 executing a program prepared in advance.

  First, the control unit 72 reads travel history data from the travel history DB 76 (step S31), and extracts continuous low-speed travel coordinates, that is, low-speed and slightly low-speed travel coordinates (step S32). Next, the control unit 72 creates a line segment by connecting the extracted travel coordinates in the low speed zone, detects this as a low speed section (step S33), and determines whether the low speed section is longer than a predetermined distance (step S33). Step S34). When the low speed section is longer than the predetermined distance (step S34: Yes), the control unit 72 determines that the traffic congestion degree of the low speed section is “congestion” and stores it in the traffic information DB 77 (step S35). On the other hand, when the low speed section is equal to or less than the predetermined distance (step S34: No), the control unit 72 does not determine that the traffic congestion degree of the low speed section is “traffic jam” and ends the process.

  The server 7 transmits to the navigation device 1 and displays the traffic congestion degree “traffic jam” stored in the traffic jam information DB 77 in step S35. At this time, the server 7 may store the line segment shape of the low speed section determined to be a traffic jam. By doing so, the server 7 can transmit the line segment shape of the low speed section when transmitting the traffic jam information to the navigation device 1, and the navigation device 1 maps the traffic jam area using the received line segment shape. Can be displayed on the data.

  As described above, according to the first congestion degree determination method, when the low speed section formed by the running coordinates in the continuous low speed zone is equal to or less than the predetermined distance, the congestion degree of the low speed section is determined as the traffic congestion. do not do. Therefore, it is possible to prevent a situation in which a low speed band is generated due to a signal waiting, a temporary stop, or the like from being erroneously determined as traffic jam.

  As described above, the travel history DB 76 of the server 7 stores travel history data of a plurality of vehicles from the plurality of navigation devices 1. The server 7 may execute the above determination process by simultaneously using the travel history data of a plurality of vehicles. Instead, the server 7 performs the above-described determination process for each travel history data of one vehicle, determines the degree of congestion, and combines the determination results of a plurality of vehicles (for example, by averaging). ) It is also possible to determine the final congestion level.

(Second method for determining the degree of traffic congestion)
Next, the second congestion degree determination method will be described. The second congestion degree determination method calculates the average speed for each road link and determines the congestion degree. When the average speed of a short road link is low, the traffic congestion degree is re-determined after connecting adjacent road links to ensure a sufficient link length. This will be described in detail below.

  FIG. 9 is a diagram for explaining a second congestion degree determination method. Similarly to FIG. 7, the server 7 arranges a plurality of travel coordinates on the road link. Then, the server 7 calculates the average speed (average link travel time) for each link. In the example of FIG. 9, the average speed of link A is calculated to be 45 km / h, the average speed of link B is 14 km / h, and the average speed of link C is calculated to be 7 km / h.

  Next, the server 7 determines the degree of congestion for each link based on the average speed. Now, as an example of criteria for determining the degree of traffic congestion, for general roads, 15 km / h or less is judged as “congested”, 15-25 km / h as “crowded”, and 25 km / h or more as “smooth”. To do. Note that the criterion for determining the degree of congestion is set for each road type. For example, another criterion is used for expressways. According to this criterion, in the example of FIG. 9, it is determined that the link A is “smooth”, the link B is “congested”, and the link C is “congested”.

  Next, the server 7 determines whether the link length of the road link whose degree of congestion is determined as “congested” or “congested” is sufficiently long, or more specifically, longer than a predetermined link length. As a result, as shown in FIG. 9, it is determined that the link B is shorter than the predetermined link length and the link C is longer than the predetermined link length.

  As described with reference to FIG. 4, when the link length is short, there is a possibility that a signal waiting or a pause is erroneously determined as a traffic jam. Therefore, when the link length of the road link determined as “congested” or “congested” is shorter than the predetermined link length, the server 7 combines the road link with the adjacent road links and re-establishes the degree of congestion. judge. In a specific period, assuming a combined link obtained by combining the link B with the link A and the link C before and after the link B, the average speed of the combined link is calculated, and the degree of congestion is re-determined. In the example of FIG. 9, it is assumed that the average speed of the combined link obtained by connecting the link A and the link C to the link B is 20 km / h. According to the above-mentioned criteria for determining the degree of traffic congestion, 20 km / h is determined as “congested”. Therefore, in this example, the congestion degree of link B is finally determined as “congested”. Note that the congestion levels of the link A and the link B remain the first determination results, and are “smooth” and “traffic jam”, respectively.

  As described above, in the second congestion level determination method, after determining the congestion level based on the average speed for each road link, the link length of the road link determined as “congested” or “congested” is It is determined whether it is long enough. And about the road link whose link length is shorter than predetermined link length, a traffic congestion degree is determined with the average speed of the joint link which connected the adjacent link before and behind being connected. Thereby, it is ensured that the link length when finally determined as “congestion” or “congestion” is a link longer than the predetermined link length. That is, “congestion” or “congestion” is not determined based on a road link or a combined link shorter than the predetermined link length. Therefore, it is possible to prevent erroneous determination of the degree of congestion for short road links.

  FIG. 10 is a flowchart of determination processing by the second congestion degree determination method. This process is performed by the control unit 72 of the server 7 executing a program prepared in advance. This determination process is performed in order for each link.

  First, the control unit 72 reads travel history data of one road link to be determined from the travel history DB 76 (step S41), calculates the average speed of the road link, and determines the degree of congestion (step S42). . Specifically, the control unit 72 determines whether the road link is “smooth”, “congested”, or “congested”.

  Next, the control unit 72 determines whether or not the degree of congestion of the road link is “congestion” or “congestion” (step S43). Note that the link whose degree of congestion is determined as “congested” or “congested” is a section with a low average speed, and corresponds to the “low speed section” of the present invention.

  When the traffic degree of the road link is “smooth” (step S43: No), the control unit 72 stores “smooth” as the congestion degree of the road link in the traffic information DB 77 (step S45), and ends the process. .

  On the other hand, when the degree of congestion of the road link is “congestion” or “congested” (step S43: Yes), the control unit 72 determines whether the link length of the road link is sufficiently long, that is, longer than the predetermined link length. It is determined whether or not (step S44). When the link length of the road link is sufficiently long (step S44: Yes), the control unit 72 stores “congestion” or “congestion” which is the current determination result as the congestion degree of the road link in the congestion information DB 77 ( Step S45), the process is terminated.

  On the other hand, when the link length of the road link is not sufficiently long, that is, when the link length is equal to or shorter than the predetermined link length (step S44: No), the control unit 72 acquires travel history data of the road link adjacent to the road link. Then (step S46), the average speed of the combined link formed by connecting adjacent links is calculated, and the degree of congestion is re-determined (step S47). Then, the process returns to step S43. And the process after step S43 is repeated.

  As a result, when the congestion degree of the combined link becomes “smooth”, “smooth” is stored as the congestion degree of the original link that is the determination target (step S45). Further, when the degree of congestion of the combined link is “congestion” or “congested”, it is further determined whether or not the combined link has a sufficient link length. If the link length is sufficient, the degree of congestion is stored. (Step S45). On the other hand, if the combined link is not yet a sufficient link length (step S44: No), the process proceeds to step S46, and the congestion degree is re-determined for the combined link obtained by combining the adjacent links before and after (step S47).

  As described above, according to the second congestion degree determination method, only when the determination target road link or the link length of the determination target link is sufficiently long, the determination target road link is “congested” or “congested”. Congestion level will be saved. Therefore, it is possible to prevent erroneous determination of traffic waiting as a signal waiting or temporary stop for a short road link.

(Congestion information transmission process)
Next, a process for transmitting the traffic jam information determined as described above to the navigation device 1 will be described. FIG. 11 is a flowchart of the traffic jam information transmission process. This process is executed by the navigation device 1 and the server 7.

  First, the navigation apparatus 1 acquires the output of various sensors and time information (step S51), and determines whether the reception timing of traffic jam information has arrived (step S52). For example, when the traffic jam information is acquired from the server 7 at regular time intervals, the navigation device 1 determines whether or not the constant time has elapsed. Moreover, when acquiring traffic jam information from the server 7 for every fixed travel distance, the navigation apparatus 1 determines whether it traveled a fixed distance.

  When the reception timing of traffic jam information has arrived (step S52: Yes), the navigation device 1 transmits a traffic jam information request to the server 7 (step S53). At this time, the navigation device 1 transmits a request for traffic jam information including the current position of the vehicle.

  When the server 7 receives the traffic jam information request from the navigation device 1 (step S54), it refers to the traffic jam information DB 77 and acquires the traffic jam information around the current position of the vehicle included in the traffic jam information request (step S55). . Specifically, the server 7 acquires a corresponding traffic jam degree for each road link within a predetermined range from the current position of the vehicle. Then, the server 7 transmits the acquired degree of traffic jam for each road link as traffic jam information to the navigation device 1 (step S56).

  The navigation device 1 receives the traffic jam information from the server 7 (step S57) and displays it on the map displayed on the display 44 (step S58). Thus, the traffic jam information transmission process ends.

  In the above example, the navigation device 1 includes the current position of the vehicle in the traffic jam information request, but instead, the traffic information may be requested by specifying a range for requesting the traffic jam information. In the above example, the server 7 provides traffic information in response to a request from the navigation device 1. Alternatively, the server 7 may provide traffic information to the navigation device 1 by push distribution. Good. For example, information such as a travel route to the destination is transmitted from the navigation device 1 to the server 7 and registered in the server 7. The server 7 transmits the traffic jam information to the navigation device 1 at regular time intervals or whenever the traffic jam information on the travel route changes.

[Modification]
In the above embodiment, an in-vehicle navigation device is illustrated, but instead, the present invention can also be applied using a mobile terminal such as a smartphone that executes a navigation app as a navigation device.

1 navigation device 5 vehicle 7 server 22 CPU
72 Control Unit 76 Travel History DB
77 Traffic jam information DB

Claims (1)

Speed acquisition means for acquiring the average speed of the moving body for each section corresponding to the road connecting the intersections;
A low speed section detecting means for detecting a section where the acquired average speed is equal to or lower than a predetermined speed as a low speed section;
When the low speed section is shorter than a predetermined distance, the average speed of the moving body in the combined section obtained by combining the preceding and following sections adjacent to the low speed section is acquired, and the average speed in the combined section is equal to or lower than the predetermined speed. A judging means for judging the low speed section as a traffic jam section;
A traffic jam judging device comprising:

Images