JPH0438599A - Road traffic information offering system - Google Patents

Abstract

PURPOSE:To compress a transmitting data quantity by preparing the modification coefficient of reference traveling time as traffic information to be offered from a ground side device to an on-vehicle device and moreover, representing traffic jam information with the high order block of it. CONSTITUTION:The traveling time measuring data of many vehicles are collected from plural machines on road 11, a reference traveling time modification coefficient is prepared as traffic information to be offered to the vehicle with referring to the traffic information from a traffic control center 15 adding to them and they are transmitted to the respective vehicles through the machines on road 11 in a traffic information processing center 14. Besides, the high order block of the modification coefficient indicates the degree of traffic jam. Then, a traffic information offering processing part 3 knows the degree of traffic jam from the high order block of the modification coefficient, ranks it with color-coding on a map and display it.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Applications The present invention relates to a system for providing road traffic information to an on-vehicle device as digital data.

<Conventional technology> As a road traffic information provision system, conventionally, Fig. 5 ta+
CA CS (Compr@hensive＾u
tomobileTraffic Control
System: Vehicle comprehensive control system), Figure 5 (b
) ALI-S COUT system (West Germany),
AMT ICS (Advanced) shown in Figure 5 tc+
ed Mobile Traffie information
ion & Comw＊Uniation System
ewa (New Vehicle Traffic Information and Communication System) is known.

■ With CAC3, the ground-side device obtains traffic information from vehicles that receive driving route guidance services, and from this traffic information, the ground-side device searches for the optimal route for each vehicle and provides guidance to the driver of each vehicle. This system guides the driver by giving directions at intersections.

Specifically, as shown in FIG. 5fa), each time the on-vehicle device 20 of each vehicle enters the communication zone with the roadside device, it receives the identification number (vehicle number) data 21 of its own vehicle via the roadside device. It is sent to the ground side device 30. The ground-side device 30 tracks communication times with on-road devices for each specific vehicle, calculates and collects travel time for each road unit (link) 11431, and creates multiple routes for each destination at any time from the collected travel time information. Create step 32.

When the driver wants to obtain road traffic information, the on-vehicle device 20 sends the vehicle number and destination data 22 to the ground-side device 30 via the road device. A search 34 is performed for a plurality of routes suitable for the traffic situation, an optimal route is selected 35 based on the traffic situation at that time, and a course instruction 36 is given at each intersection. The on-vehicle device 20 transmits a route instruction 23 to the driver, and the driver takes the route.

However, the system CAC3 mentioned above (see below ■-(it
~(There are inconveniences like M.

■-(i)! Since the J-link travel time is collected from vehicles based on the vehicle number data 21, the system cannot function effectively until vehicles equipped with the in-vehicle device 20 become widespread. Conversely, the vehicle does not install the on-vehicle device 20 until good service is provided. Because of this dilemma, it is difficult to disseminate CAC3 in stages.

■-(■) Ground side device 30 calculates and collects travel time 31
, creation of multiple routes for each destination 32, search for multiple routes suitable for the destination 34, selection of the optimal route 35, and road instructions at intersections 36 are all processed centrally, so the load on the ground side device 30 is heavy. Therefore, it is difficult to realize this in terms of processing power and cost.

■-1 Since the on-vehicle device 20 communicates with the roadside device, it is a point-of-sight communication, so in many cases the driver is far away from the roadside device when he or she starts a trip, making it difficult to obtain the desired information. Can not.

■-1 Drivers only receive route instructions 36 at each intersection, so they do not know the entire route to their destination.
There is a lack of information.

■ On the other hand, at AL l-3COUT: As shown in Fig. 5 tb+, the on-vehicle device 20 measures the travel time 24 of the link from the travel of the own vehicle, and sends the measurement result to the ground-side device 3.
0 via the roadside device. The ground side device 30 performs IJ link travel time collection 1a37 from each car, and as needed.
A plurality of routes are created 32 for each destination. Then, when the driver wants to obtain traffic information, the in-vehicle device 20
Request for provision of traffic information via roadside equipment 25. is sent to the ground-side device 30. In response to the request 25, the ground-side device 30 selects an optimal route 38 from the point in question to each destination based on the traffic situation at that time from the created frequency routes for each destination, and sends the selection 38 to the on-vehicle device 20. From this optimal route for each destination, the on-vehicle device 20 selects a route 26 that matches the destination input by the driver, and provides course instructions 27 at each intersection according to the selected route. The driver should follow these instructions.
choose a course.

However, the above system ALE-5COUT also has CA
Similar to CS, there are the following disadvantages.

■-(1) The on-vehicle device 20 measures the link travel time, and the ground-side device 30 collects this, so the on-vehicle device 1 [20
The system will not be able to function effectively until it becomes widespread enough that vehicles equipped with it. Conversely, the vehicle does not install the on-vehicle device 20 until good service is provided. Because of this dilemma, it is difficult to disseminate it in stages, similar to CACS.

■-(ii) Although the processing is not as intensive as in CAC3, the ground unit w30 still performs processing such as collecting travel time information 37, creating multiple routes for each destination 32, and selecting the optimal route for each destination 38. The load on the ground-side equipment 30 is heavy (9), and it is difficult to realize this in terms of processing capacity and cost.

- Since the in-vehicle device 20 communicates with the roadside device, it is a point-of-sight communication, so the driver is often far away from the roadside device when he starts his trip, and can obtain the desired information. I can't.

■-(Ivl) Since the driver only receives route instructions 27 at each intersection, he does not know the entire route to the destination and lacks information.

■Next, AMT I CS uses an existing traffic control center, and as shown in Figure 5(e), the traffic control center collects and processes traffic information and collects congestion information39.
The ground-side device 30 obtains this and broadcasts it 40. The in-vehicle device 20 receives the broadcast and displays traffic jam information 28 superimposed on the map. Drivers look at traffic congestion information on the map and decide their own routes.

However, the above system AMT ICS has the following ■-(
There are disadvantages such as il~-.

-(i) The traffic congestion information display 28 only indicates the degree of congestion, and there is no link travel time data sufficient for the driver to determine the optimal route, making route guidance difficult.

-(ii) When the number of congested sections increases, it becomes virtually impossible for the driver to judge the route by looking at the display.

■-1 Other means are required to collect link travel times.

■ Therefore, the system shown in FIG. 6 has been considered.

In the figure, an on-vehicle device 20 measures a link travel time 24 from the travel of its own troops and transmits it to a ground-side device 30. The ground unit W30 collects the link travel time from the on-board device 20 of each vehicle, but it also transmits the collected link travel time information to each vehicle as it is or with little processing, and receives this information and sends it to the vehicle. The device 20 performs a route search 28;
Displays a route 29 that matches the destination and provides route instructions 27
issue.

Although this system reduces the data processing burden on the ground-side device I30, it does have the following disadvantages: (i)-(it, (ii)).

■-(i)! There is a large amount of J link travel time information (all of it is transmitted from the ground side device 30 to the onboard device 20, which increases the burden on the transmission means. Also, the onboard device 20 transmits raw link travel time information from the ground side device 30). Since the route search 28 is performed from the beginning, the processing load on the in-vehicle device 20 becomes too large.

■-(ii) If only the route display 29 is used, traffic jam information cannot be understood. Although link travel times can be displayed on the map, it is easier for drivers to view traffic congestion information.

<Problems to be Solved by the Invention> An object of the present invention is to provide a road traffic information providing system that solves the problems of the prior art described above.

Means for Solving the Problems> The road traffic information providing system according to the present invention includes a means for storing reference travel time information of each link, and a means for storing reference travel time information for each link, means for providing route to ground, course at intersections, and traffic congestion information; means for measuring link travel time; transmission of measured link travel time information to ground-side equipment; and reception of traffic information from ground-side equipment. an on-vehicle device having a wireless communication means for communicating with the on-vehicle device; Based on the means for collecting the traffic congestion information and the link travel time from the on-vehicle device, a standard travel time modification coefficient that modifies the standard travel time of each link as the traffic information is transmitted by assigning its upper block to the traffic congestion information. and a ground-side device comprising means.

Function> When the on-vehicle device cannot obtain traffic information from the ground-side device, such as at the start, it searches for a route that matches the destination from the reference travel time information for each link that it has, and displays it on the map. , displays the route at each intersection.

If traffic information is available, the standard travel time is modified with a modification coefficient, a route suitable for the destination is searched, and the route is displayed on the map and at each intersection. Furthermore, since the traffic information is a modification coefficient for the standard travel time, and its upper block is traffic congestion information, traffic congestion information is provided by voice or display on a map according to the contents of the upper block.

In this case, the ground-side device sends not the link travel time itself but a coefficient modifying the reference travel time to the on-vehicle device, so the amount of transmission is small and the burden of transmission processing is reduced.

Embodiment> An embodiment of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 shows a system configuration, in which an in-vehicle device 1 includes a memory 2, a traffic information provision processing section 3, a travel time measurement processing section 4,
It has a mobile radio device 5. The ground side device 10 is a roadside device 11
, a traffic information processing center 14 , and a traffic control center 15 , and the roadside device 11 has a fixed radio 8!12 and a communication control device 13 . FIG. 2 shows the processing flow of this system, FIG. 3 shows an example of the format of the reference travel time modification coefficient, and FIG. 4 shows an example of the timing of transmission and reception between the vehicle side and the ground side.

The memory 2 of the on-vehicle device 1 stores the standard travel time of each link in advance. This standard travel time is the travel time of each link when there is no traffic jam, or the average travel time based on statistics, and is determined in advance by an appropriate method.

The travel time measurement processing unit 4 of the on-vehicle device 1 uses an independent navigation system, and measures and stores the travel time for each link as the vehicle travels, and when the vehicle approaches the roadside device 11. , for example, a fixed wireless device 1 in a very small zone of a roadside device.
When the mobile radio 5 enters the communication area 2, the mobile radio 5 transmits the measurement results.

The roadside machine 1 collects travel time measurement data from vehicles passing through the communication station, and sends it to the traffic information processing center 14.
Send by wire or wireless communication.

The traffic information processing center 14 collects travel time measurement data of a large number of vehicles from various roadside devices 11, and uses this data as standard traffic information to be provided to vehicles while referring to the traffic information from the traffic control center 15. Create a travel time modifier,
It is sent to each vehicle via road fill.

Here, the surroundings of the roadside machine providing information (for example, the number of
N degree), each reference piece creates a time R modification coefficient for each thin link, and then it is used as wide-area information for distant areas, and for each coarse link, and also takes into account predictions of future changes in traffic conditions. An rR modification coefficient is created for each group when traveling 1 m.

As shown in FIG. 3, the data format of the standard travel time modification coefficient consists of a link number section 16 and a modification coefficient section 17.
bit) 17A and lower block (e.g. 6 bits) 17
Consists of B.

This modification coefficient is applied to the traffic information provision processing unit 3 of the in-vehicle system 'It1.
may be multiplied by the standard travel time of the corresponding link in memory 2 to the power of 2, and the travel time at that point can be obtained. Then, the traffic information provision processing unit 3 calculates and obtains the optimal route that matches the driver's destination from the modified (or unqualified if there is no information) travel time information, and displays the route to the destination on the map. Furthermore, each time the vehicle approaches an intersection, the direction of travel is indicated by audio guidance or visual route display.

Further, the upper block 17A of the modification coefficient indicates the degree of traffic congestion, and for example, in the case of 2 pits, the correspondence is as shown in the table.

The table and traffic information provision processing unit 3 learns the degree of congestion from the upper block of the modification coefficient, and displays it on the map by ranking it by color.

In this way, by introducing the reference time modification factor,
For example, in the case of 8 pits, the travel time can be provided with an accuracy of 1/2 S6, and the higher bits can represent the degree of congestion according to the degree of increase in travel time.

Note that the reference time modification coefficient is provided in priority to links where traffic congestion has occurred, and the in-vehicle device 1 considers links without this modification coefficient to be congested, and uses the reference travel time to calculate the route. Give directions. Therefore, the system allows the number of links providing information to be gradually increased, allowing for gradual construction of the system.

In addition, in the early stages of system startup, the amount of traffic information collected is small and the accuracy of the modification coefficient is difficult to improve. The route calculation can be performed by modifying the standard travel time when the travel time is reached.

Furthermore, traffic congestion information can be obtained by the traffic information center 14 by collecting travel time measurement data from the measurement processing unit 4 of each vehicle, but the existing traffic control center 15 originally has
Since traffic congestion information is available, by utilizing this information, it is possible to obtain traffic congestion information from the traffic control center 15 and start system services even if travel time information is not collected from vehicles or is insufficient. can.

The traffic control center 15 collects traffic information using vehicle detectors on the road, obtains traffic congestion information, controls traffic signals, or provides traffic information using variable traffic signs and the like.

By the way, since the fixed radio device 12 of the roadside device 11 performs minimal zone communication, traffic information is not known until the vehicle encounters the first roadside device, but the memory 2 of the onboard device 1 stores the standard travel time of each link. Because it is stored, it is possible to search for routes to a certain extent. Therefore, after encountering the first roadside aircraft, there is almost no chance that a completely different route (8i! Back, for example) will be chosen.

<Effects of the Invention> According to the present invention, the on-vehicle device has reference travel time information for each link, the traffic information provided from the ground side device to the on-vehicle device is a modification coefficient of the reference travel time, and furthermore, the upper block is a modification coefficient of the reference travel time. Since it represents traffic congestion information, it has the following effects.

(i) The amount of data to be transmitted is compressed, reducing the burden of transmission processing.

(II) It is possible to smoothly transition from a service that only provides traffic congestion information to a service that also uses travel time, and the system can be expanded in stages.

- Even before the on-vehicle device receives the modification coefficient from the ground-side device, the on-vehicle device can calculate the route using the built-in reference travel time information, so it is possible to provide route guidance to a certain extent.

It also provides information on routes, directions at intersections, and traffic jams, resolving the lack of information for drivers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the processing flow, FIG. 3 is a diagram showing the format of the modification coefficient, FIG. 4 is a diagram showing the timing of transmission and reception, and FIG. 5 and 6 are diagrams showing the prior art. In the figure, 1 is an on-vehicle device, 2 is a memory, 3 is a traffic information provision processing unit, 4 is a travel time measurement processing unit, 5 is a mobile radio device, 10 is a ground side device, 11 is a roadside device, and 12 is a fixed radio. 13 is a communication control device, 14 is a traffic information center, and 15 is a traffic control center. Patent application agent Sumitomo Electric Industries Co., Ltd.

Claims (1)

[Claims] Means for storing reference travel time information of each link, and means for storing the route to the destination, the course at the intersection, and traffic congestion information based on the reference travel time information and the traffic information transmitted from the ground side device. an in-vehicle device comprising: a means for providing link travel time; a means for measuring link travel time; and a wireless communication means for transmitting measured link travel time information to a ground-side device and receiving traffic information from the ground-side device; A roadside device having a fixed wireless means in a very small zone that communicates with the wireless communication means of the device, a means for controlling communication between the on-vehicle device and the ground-side device, a means for collecting traffic congestion information, and a means for collecting the traffic congestion information and the on-vehicle device. A ground-side device comprising means for transmitting a reference travel time modification coefficient for modifying the reference travel time of each link as the traffic information based on the link travel time, and assigning its upper block to traffic congestion information. A road traffic information provision system.