Apparatus and program for route search

• US 8,200,417 B2
• Filed: 09/09/2008
• Issued: 06/12/2012
• Est. Priority Date: 09/26/2007
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Hamaguchi, Kenichi
• Primary Examiner(s): Koppikar, Vivek
• Assistant Examiner(s): Winston, III, Edward
• Application Number:
  US12/230,963
• Publication Number:
  US 20090082956A1
• Time in Patent Office: 1,372 Days
• Field of Search: 701/45, 701/201, 701/207, 701/213, 701/208, 706/12, 706/20
• US Class Current: 701/207
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network

Abstract

A route search apparatus stores a section of a route to a database when drowsiness of a driver is detected by a drowsiness detector in the section of the route. The route search apparatus refers to the database and determines whether route candidates include a drowsiness-detected route section when the apparatus searches for a route extending from a departure place to a destination. When the drowsiness-detected route section is included in the route candidates, an evaluation value of the drowsiness-detected route section is raised before re-searching the route extending from the departure place to the destination.

Claims

1. A route search apparatus equipped with a route search unit that computes an evaluation value of each section of a route from a departure place to a destination and retrieves a route by which a total evaluation value is minimized from among route candidates that provide a route from a departure place to a destination, the route search apparatus comprising:

a drowsiness detector that detects the drowsiness of a driver of a vehicle; and

a control device that facilitates

storing in a storage unit a driving section where the drowsiness of the driver was detected by the drowsiness detector with a time of day in which the drowsiness was detected;

referring to the storage unit and determining whether or not the driving section where the drowsiness of the driver was previously detected is included in a route candidate,

computing a period of time in which the vehicle passes the driving section where the drowsiness of the driver was previously detected, the period of time being determined when it is determined that the driving section where the drowsiness of the driver was detected is included in a route candidate, and

referencing the storage unit to determine whether the period of time that the vehicle passes the driving section matches the time of day in which drowsiness was previously detected for the driving section,

when it is determined that the route candidate includes the driving section where the drowsiness of the driver was previously detected increasing the evaluation value of the driving section where the drowsiness of the driver was detected, and searching for an alternate route from the departure place to the destination, and

determining that the period of time matches the time of day that the drowsiness of the driver was previously detected for the driving section, increasing the evaluation value of the driving section where the drowsiness of the driver was detected and searching for an alternate route from the departure place to the destination.

2. The route search apparatus of claim 1,

wherein, when a section where the drowsiness of the driver was detected is included in a retrieved route, the control device causes a displaying unit to display information indicating that a section where the drowsiness of the driver was detected is included in the retrieved route.

3. A route search apparatus equipped with a route search unit that computes the evaluation value of each section of a route from a departure place to a destination, and retrieves a route by which the total evaluation value is minimized from among route candidates that provides a route from a departure place to a destination, the route search apparatus comprising:

a drowsiness detector that detects drowsiness of a driver; and

a control device that

stores in a storage unit a driving section where the drowsiness of the driver was detected by the drowsiness detector and a probability ratio that provides a number of times drowsiness of the driver was detected in the driving section and the number of times the driving section has been driven,

references the storage unit to determine whether or not a driving section where the drowsiness of the driver was previously detected is included in a route candidate, and

when it is determined that the route candidate includes the driving section where the drowsiness of the driver was previously detected extracts the probability ratio of each driving section where the drowsiness of the driver was previously detected and is included in the route candidate, and searches for an alternate route, from among all route candidates, by which the total of the probability ratio of the driving sections where the drowsiness of the driver was detected is minimized.

4. The route search apparatus of claim 3, wherein the control device

stores a period of time during which the drowsiness of the driver was detected together with the section where the drowsiness of the driver was detected in the storage unit,

computes a period of time during which the section where the drowsiness of the driver was detected in the route candidate is passed through when it is determined by the first determination unit that a section where the drowsiness of the driver was detected is included in a route candidate from the departure place to the destination,

refers to the storage unit and determines whether or not a period of time during which a section where the drowsiness of the driver was detected in the route candidate is passed through and a period of time during which a section where the drowsiness of the driver was detected was passed through match with each other, and

when it is determined that a section where the drowsiness of the driver was detected is included in a route candidate from the departure place to the destination and it is determined that the period of time during which a section where the drowsiness of the driver was detected in the route candidate is passed through and the period of time during which a section where the drowsiness of the driver was detected was passed through match with each other, extracts the frequency of each section included in the route candidate with which the drowsiness of the driver was detected and searches for a route by which the total of the frequencies of the sections with which the drowsiness of the driver was detected is minimized from among route candidates from the departure place to the destination.

5. The route search apparatus of claim 4, wherein the control device

stores a section where the drowsiness of the driver was detected, a period of time during which the drowsiness of the driver was detected, and the point of start of driving during which the drowsiness of the driver was detected in the storage unit,

refers to the storage unit to determine whether or not the point of start in the route candidate and a present position match with each other and refers to the storage unit to determine whether or not a period of time during which a section where the drowsiness of the driver was detected in the route candidate is passed through and a period of time during which a section where the drowsiness of the driver was detected was passed through match with each other, and

when it is determined that the point of start in the route candidate and the present position match with each other and the period of time during which the section where the drowsiness of the driver was detected in the route candidate is passed through and the period of time during which the section where the drowsiness of the driver was detected was passed through match with each other, extracts the frequency of each section included in the route candidate with which the drowsiness of the driver was detected and searches for a route by which the total of the frequencies of the sections with which the drowsiness of the driver was detected is minimized from among route candidates from the departure place to the destination.

6. The route search apparatus of claim 3,

wherein, when a section where the drowsiness of the driver was detected is included in a retrieved route, the control device causes a displaying unit to display information indicating that a section where the drowsiness of the driver was detected is included in the retrieved route.

7. A route search apparatus equipped with a route search unit that computes an evaluation value of each section of a route from a departure place to a destination, and retrieves a route by which a total evaluation value is minimized from among route candidates that provide a route from the departure place to the destination, the route search apparatus comprising:

a drowsiness detector that detects drowsiness of a driver of a vehicle; and

a control device that;

stores in a storage unit a driving section where the drowsiness of the driver was detected by the drowsiness unit with a starting point;

references the storage unit to determine whether or not a driving section where the drowsiness of the driver was previously detected is included in a route candidate;

references the storage unit to determine whether or not a departure place of driving during which the drowsiness of the driver was previously detected, as stored in the storage unit, matches the current departure place;

determines that the route candidate includes a driving section where the drowsiness of the driver was previously detected, the first route search unit increases the evaluation value of the driving section where the drowsiness of the driver was detected, and searches for an alternate route from the departure place to the destination; and

determines that the departure place of driving during which the drowsiness of the driver was previously detected matches the current departure place, the route search unit increases the evaluation value of the section where the drowsiness of the driver was detected and searches for an alternate route from the departure place to the destination.