ROUTE SEARCHING DEVICE

• US 20110160993A1
• Filed: 12/28/2009
• Published: 06/30/2011
• Est. Priority Date: 12/28/2009
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Aoki, Yoshinori, Takemasa, Koichiro, Mineta, Kenichi, TSURUTANI, Taisuke
• Granted Patent: US 8,793,067 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 21/3469 Fuel consumption; Energy use; Emission aspects

Abstract

A route searching device according to an embodiment of the invention includes an estimated fuel consumption amount computing unit that computes an estimated fuel consumption amount of each interval constituting plural routes from a departure point to a destination and an optimum route selecting unit that selects a route in which a total of the estimated fuel consumption amount from the departure point to the destination is minimized. The estimated fuel consumption amount computing unit includes a cruise fuel consumption amount computing unit that computes a cruise fuel consumption amount for each interval by multiplying a distance of the interval and a fuel consumption rate determined according to an average vehicle speed a vehicle-speed fluctuation fuel consumption amount computing unit that computes a vehicle-speed fluctuation fuel consumption amount for each interval in each road category by multiplying the distance of the interval and the a fuel consumption rate, the fuel consumption rate being determined from an average vehicle speed and the road category of the interval and a gradient fuel consumption amount computing unit that computes a gradient fuel consumption amount for each interval by multiplying the distance of the interval and a fuel consumption rate determined according to a road average gradient. The estimated fuel consumption amount is obtained by adding the cruise fuel consumption amount, the gradient fuel consumption amount, and the vehicle-speed fluctuation fuel consumption amount.

Claims

1. A route searching device that searches a vehicle running route, the route searching device comprising:

an estimated fuel consumption amount computing unit that computes an estimated fuel consumption amount of each interval constituting a plurality of routes from a departure point to a destination, and

an optimum route selecting unit that selects a route in which a total of the estimated fuel consumption amount from the departure point to the destination is minimized,

wherein the estimated fuel consumption amount computing unit includes;

a cruise fuel consumption amount computing unit that computes the cruise fuel consumption amount for each interval by multiplying a distance of the interval and a fuel consumption rate determined according to an average vehicle speed,

a vehicle-speed fluctuation fuel consumption amount computing unit that computes the vehicle-speed fluctuation fuel consumption amount for each interval in each road category by multiplying the distance of the interval and a fuel consumption rate, the fuel consumption rate being determined from an average vehicle speed and the road category of the interval, and

a gradient fuel consumption amount computing unit that computes the gradient fuel consumption amount for each interval by multiplying the distance of the interval and a fuel consumption rate determined according to a road average gradient,

wherein the estimated fuel consumption amount is obtained by adding the cruise fuel consumption amount, the gradient fuel consumption amount, and the vehicle-speed fluctuation fuel consumption amount.

2. The route searching device according to claim 1, wherein the fuel consumption rate determined from the average vehicle speed and the road category of the interval for an expressway is larger than the fuel consumption rate for an urban road, and

a difference of the fuel consumption rate between the urban road and the expressway increases with decreasing average vehicle speed.

3. The route searching device according to claim 1, wherein the gradient fuel consumption amount computing unit sets (i) the fuel consumption rate to a value that increases with increasing average gradient in each interval, (ii) the fuel consumption rate for the urban road smaller than that for the expressway in case of a rising gradient, and (iii) the fuel consumption rate for the urban road larger than that for the expressway in case of a falling gradient.

4. The route searching device according to claim 1, further comprising an air-conditioner fuel consumption amount computing unit that computes a fuel consumption amount of an air conditioner by multiplying an estimated running time in each interval and air-conditioner power consumption determined according to an ambient temperature,

wherein the estimated fuel consumption amount computing unit adds the fuel consumption amount of the air conditioner to the estimated fuel consumption amount.

5. The route searching device according to claim 2, further comprising an air-conditioner fuel consumption amount computing unit that computes a fuel consumption amount of an air conditioner by multiplying an estimated running time in each interval and air-conditioner power consumption determined according to an ambient temperature,

wherein the estimated fuel consumption amount computing unit adds the fuel consumption amount of the air conditioner to the estimated fuel consumption amount.

6. The route searching device according to claim 3, further comprising an air-conditioner fuel consumption amount computing unit that computes a fuel consumption amount of an air conditioner by multiplying an estimated running time in each interval and air-conditioner power consumption determined according to an ambient temperature,

wherein the estimated fuel consumption amount computing unit adds the fuel consumption amount of the air conditioner to the estimated fuel consumption amount.