NAVIGATION SERVER AND NAVIGATION SYSTEM

• US 20170178502A1
• Filed: 12/19/2016
• Published: 06/22/2017
• Est. Priority Date: 12/22/2015
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: KAWASAKI, Shunsuke
• Granted Patent: US 10,553,108 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 21/3691 Retrieval, searching and output of information related to real-time traffic, weather, or environmental conditions arrangements for giving variable traffic instructions G08G1/09
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0133 for classifying traffic situation
• CPC Class Codes: G08G 1/0141 for traffic information dissemination
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P
• CPC Class Codes: G08G 1/065 by counting the vehicles in a section of the road or in a parking area, i.e. comparing incoming count with outgoing count
• CPC Class Codes: G08G 1/096822 where the segments of the route are transmitted to the vehicle at different locations and times
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data
• CPC Class Codes: G08G 1/096866 where the complete route is shown to the driver
• CPC Class Codes: G08G 1/0969 having a display in the form of a map

Abstract

Provided is a navigation server capable of improving reliability or estimation accuracy of traffic state information for a user in view of the present traffic state. A partial movement cost Cik being each of movement costs in plural partial links Lik constituting a designated link Li is used to determine a total movement cost Ci in the designated link Li. The higher an occupancy ratio r of a first partial link Lim among a series of the partial links Lik, the more preferentially a partial movement cost Cim in the first partial link Lim is used than a partial movement cost Cin in a second partial link Lin to determine the total movement cost Ci of the designated link Li. In particular, only the partial movement cost Cim in the first partial link Lim is used to determine the total movement cost Ci of the designated link Li.

Claims

1. A navigation server comprises:

a server storage device;

a first server computing element configured to recognize probe information including time series of positions of each of a plurality of navigation clients based on communication with each of the plurality of navigation clients serving as a mobile station and determine, as a partial movement cost, a movement cost in each of a series of partial links constituting one of or respective designated links among a plurality of links constituting a road network; and

a second server computing element configured to determine a total movement cost of the designated link composed of the series partial links by preferentially using the partial movement cost in the partial link with high freshness rather than the partial movement cost in the partial link with low freshness, the freshness being defined based on time elapsed since the first server computing element determined a last partial movement cost among the series of partial links, and store the total movement cost in the server storage device.

2. The navigation server according to claim 1, wherein the higher an occupancy ratio of a first partial link whose partial movement cost is equal to or more than a reference value in freshness among the series partial links, the more preferentially the second server computing element uses the partial movement cost in the first partial link than the partial movement cost in a second partial link, having freshness less than the reference value, to determine the total movement cost of the designated link composed of the series of the partial links.

3. The navigation server according to claim 2, wherein, if the occupancy ratio of the first partial link in the series partial links is equal to or greater than a reference ratio, the second server computing element determines the total movement cost of the designated link by using only the partial movement cost in the first partial link.

4. The navigation server according to claim 1, wherein, in a case of the designated links including at least one of an inflow point from an inflow link and an outflow point into an outflow link, the freshness of the partial movement cost in the partial links on each of an upstream side and a downstream side of the inflow point or the outflow point has a deviation equal to or greater than a threshold, the second server computing element decreases the deviation of a preferential degree of the partial movement cost in the partial link on each of the upstream side and the downstream side of the inflow point or the outflow point.

5. The navigation server according to claim 1, wherein the server storage device stores server map information in which a road network is represented by the plurality of links, and

the first server computing element uses the server map information to perform map matching on a position of the navigation client included in the prove information to identify the designated link where the navigation client has moved, and determine the partial movement cost in the designated link using the probe information.

6. The navigation server according to claim 1, wherein the server storage device stores a reference movement cost generated separately from the total movement cost based on the probe information in each of the plurality of links, and

the second server computing element determines the total movement cost in the designated link using not only the partial movement cost in at least one of partial links among the series of partial links but also the reference movement cost in the designated link composed of the series of partial links.

7. The navigation server according to claim 1, wherein the freshness is defined as a variable which becomes intermittently or continuously higher as the time elapsed since the determination of the last partial movement cost is shorter.

8. A navigation system composed of a navigation server and a plurality of navigation clients serving as a mobile station,

wherein the navigation server comprises:

a server storage device;

a first server computing element configured to recognize probe information including time series of positions of each of the plurality of navigation clients based on communication with each of a plurality of navigation clients serving as a mobile station and determine, as a partial movement cost, a movement cost in each of a series of partial links constituting one of or respective designated links among a plurality of links constituting a road network; and

a second server computing element configured to determine a total movement cost of the designated link composed of the series partial links by preferentially using the partial movement cost in the partial link with high freshness rather than the partial movement cost in the partial link with low freshness, the freshness being defined based on time elapsed since the first server computing element determined a last partial movement cost among the series of partial links, and store the total movement cost in the server storage device.