Vehicle present position detection apparatus, vehicle present position display apparatus, navigation system and recording medium

• US 6,226,591 B1
• Filed: 08/30/1999
• Issued: 05/01/2001
• Est. Priority Date: 09/24/1998
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Okumura, Mitsuo, Ozaki, Takahisa, Tsurumi, Kiyoshi
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US09/385,097
• Time in Patent Office: 610 Days
• Field of Search: 701/76, 701/207, 701/208, 701/211, 701/213, 701/210, 701/214, 701/216, 701/217, 701/220, 701/221, 701/222, 702/97, 702/96, 702/94, 342/106, 342/107, 342/108, 342/109, 342/112, 342/113, 342/115
• US Class Current: 701/216
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G08G 1/096827 where the route is computed onboard

Abstract

Navigation system, which can improve an accuracy of a travel distance calculation and an accuracy of present position detection even if an accuracy of a pulse data from a vehicle speed sensor is relatively low. The navigation system includes a gyroscope, a vehicle speed sensor and a navigation control portion. The navigation control portion calculates the travel direction based on outputs from the gyroscope and the vehicle speed sensor. When the vehicle decelerates, acceleration during low speed less than Vmin, in which the vehicle speed pulse is not outputted, is assumed to be equal to an acceleration just before the vehicle speed becomes less than Vmin. When the vehicle accelerates, acceleration during low speed less than Vmin, in which the vehicle speed pulse is not outputted, is assumed to be equal to an acceleration just after the vehicle speed becomes to or more than Vmin. Vehicle present position is calculated by estimating travel distances Dist_down and Dist_up which are estimated to travel during a pulse-missing period at deceleration and acceleration, and adding them to the travel distance Dist calculated based on the vehicle speed pulse from the vehicle speed sensor.

Claims

1. A vehicle present position detection apparatus, comprising:

an azimuth sensor that outputs an azimuth signal corresponding to an azimuth change amount of a vehicle;

a speed sensor that outputs pulse signals at an interval corresponding to a travel speed of the vehicle;

acceleration calculating means for calculating a travel acceleration of the vehicle based on the pulse signals outputted from the speed sensor; and

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using the azimuth change amount calculated based on the azimuth signal outputted by the azimuth sensor and a travel distance calculated based on the pulse signals outputted by the speed sensor,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals outputted from the speed sensor and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not outputted from the speed sensor when the vehicle travels, and the present position calculating means estimates the estimated travel distance based on the travel accelerations before and after the pulse-missing period.

2. A vehicle present position detection apparatus according to claim 1, wherein the present position calculating means estimates the estimated travel distance based on the travel accelerations just before and just after the pulse-missing period.

3. A vehicle present position detection apparatus according to claim 1, wherein the travel acceleration just before the pulse-missing period is a deceleration just before the pulse-missing period, and the travel acceleration just after the pulse-missing period is a acceleration just after the pulse-missing period.

4. A vehicle present position detection apparatus according to claim 1, wherein the present position calculating means estimates the estimated travel distance based on transitions of the travel accelerations just before and just after the pulse-missing period.

5. A vehicle present position detection apparatus according to claim 1, wherein the present position calculating means estimates the estimated travel distance based on one of a travel acceleration and a transition of the travel acceleration during the pulse-missing period estimated based on one of the travel accelerations before and after the pulse-missing period and transitions of the travel accelerations before and after the pulse-missing period.

6. A vehicle present position detection apparatus according to claim 1, further comprising:

relationship storing means for storing a relationship between;

one of a travel acceleration and a transition of the travel acceleration corresponding to a plurality of vehicle travel behaviors estimated to occur before and after the pulse-missing period; and

the estimated travel distance during the pulse-missing period,

wherein the present position calculating means estimates the estimated travel distance based on a searched data from the relationship storing means by using one of a travel acceleration and a transition of the travel acceleration occurred before and after the pulse-missing period as an index.

7. A vehicle present position detection apparatus according to claim 1, further comprising:

representative data storing means for storing representative data decided based on a travel distance with respect to a plurality of vehicle travel behavior, the travel distance being decided by a simulation with respect to a plurality of vehicle travel behavior estimated to occur before and after the pulse-missing period,

wherein the present position calculating means uses the representative data stored in the representative data storing means as the estimated travel distance during the pulse-missing period.

8. A vehicle present position detection apparatus according to claim 1, further comprising:

a radio receiver that receives a radio for a radio navigation and outputs an absolute present position and a travel direction of the vehicle,

wherein the present position calculating means corrects the present position of the vehicle obtained by the dead-reckoning navigation calculation by using the absolute present position and the travel direction of the vehicle outputted from the radio receiver.

9. A vehicle present position detection apparatus according to claim 1, wherein the present position calculating means includes:

travel locus generating means for generating a travel locus until the present position of the vehicle; and

map-matching correcting means for correcting the present position of the vehicle by using a map-matching process that compares the travel locus generating by the travel locus generating means with a road data based on a map data.

15. A vehicle present position display apparatus including the vehicle present position detection apparatus according to claim 1, further comprising:

map data storing means for storing a map data including a road map data;

map displaying means for displaying the road map data around the present position of the vehicle detected by the vehicle present position detection apparatus which is read from the map data storing means as a road map.

10. A vehicle present position detection apparatus, comprising:

an azimuth sensor that outputs an azimuth signal corresponding to an azimuth change amount of a vehicle;

a speed sensor that outputs pulse signals at an interval corresponding to a travel speed of the vehicle;

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using the azimuth change amount calculated based on the azimuth signal outputted by the azimuth sensor and a travel distance calculated based on the pulse signals outputted by the speed sensor; and

relationship storing means for storing a relationship between;

vehicle travel behaviors estimated to occur before and after the pulse-missing period; and

the estimated travel distance during the pulse-missing period,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals outputted from the speed sensor and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not outputted from the speed sensor when the vehicle travels, and

the present position calculating means estimates the estimated travel distance based on a searched data from the relationship storing means by using the vehicle travel behaviors occur before and after the pulse-missing period as an index.

12. A vehicle present position detection apparatus according to claim 10, wherein the travel acceleration just before the pulse-missing period is a deceleration just before the pulse-missing period, and the travel acceleration just after the pulse-missing period is a acceleration just after the pulse-missing period.

11. A vehicle present position detection apparatus, comprising:

an azimuth sensor that outputs an azimuth signal corresponding to an azimuth change amount of a vehicle;

a speed sensor that outputs pulse signals at an interval corresponding to a travel speed of the vehicle;

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using the azimuth change amount calculated based on the azimuth signal outputted by the azimuth sensor and a travel distance calculated based on the pulse signals outputted by the speed sensor; and

relationship storing means for storing a relationship between;

one of a travel acceleration and a transition of the travel acceleration corresponding to a plurality of vehicle travel behaviors estimated to occur before and after the pulse-missing period; and

the estimated travel distance during the pulse-missing period,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals outputted from the speed sensor and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not outputted from the speed sensor when the vehicle travels, and

the present position calculating means estimates the estimated travel distance based on a searched data from the relationship storing means by using one of a travel acceleration and a transition of the travel acceleration occurring before and after the pulse-missing period as an index.

13. A vehicle present position detection apparatus, comprising:

an azimuth sensor that outputs an azimuth signal corresponding to an azimuth change amount of a vehicle;

a speed sensor that outputs pulse signals at an interval corresponding to a travel speed of the vehicle;

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using the azimuth change amount calculated based on the azimuth signal outputted by the azimuth sensor and a travel distance calculated based on the pulse signals outputted by the speed sensor; and

representative data storing means for storing representative data decided based on a travel distance with respect to a plurality of vehicle travel behavior, the travel distance being decided by a simulation with respect to a plurality of vehicle travel behavior estimated to occur before and after the pulse-missing period,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals outputted from the speed sensor and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not outputted from the speed sensor when the vehicle travels, and

the present position calculating means uses the representative data stored in the representative data storing means as the estimated travel distance during the pulse-missing period.

14. A vehicle present position detection apparatus, comprising:

acceleration calculating means for calculating a travel acceleration of a vehicle based on a pulse signals inputted at an interval corresponding to a travel speed of the vehicle; and

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using an azimuth change amount calculated based on an azimuth signal and a travel distance calculated based on the pulse signals,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not inputted thereto when the vehicle travels, and the present position calculating means estimates the estimated travel distance based on at least one of the travel accelerations before and after the pulse-missing period.

17. A navigation system including the vehicle present position display apparatus according to claim 14, further comprising:

route guidance means for recognizably displaying a route to a predetermined destination and the present position of the vehicle detected by the vehicle present position detection apparatus on the road map displayed by the map displaying means, and performing a route guidance in view of a relationship between the route to the predetermined destination and the present position of the vehicle.

16. A vehicle present position display apparatus, comprising:

a vehicle present position detection portion including;

an azimuth sensor that outputs an azimuth signal corresponding to an azimuth change amount of a vehicle;

a speed sensor that outputs pulse signals at an interval corresponding to a travel speed of the vehicle;

acceleration calculating means for calculating a travel acceleration of the vehicle based on the pulse signals outputted from the speed sensor; and

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using the azimuth change amount calculated based on the azimuth signal outputted by the azimuth sensor and a travel distance calculated based on the pulse signals outputted by the speed sensor,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals outputted from the speed sensor and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not outputted from the speed sensor when the vehicle travels, and the present position calculating means estimates the estimated travel distance based on the travel accelerations before and after the pulse-missing period; and

a display portion including;

map data storing means for storing a map data including a road map data; and

map displaying means for displaying the road map data around the present position of the vehicle detected by the vehicle present position detection apparatus which is read from the map data storing means as a road map.

18. A navigation system, comprising:

a vehicle present position detection portion including;

an azimuth sensor that outputs an azimuth signal corresponding to an azimuth change amount of a vehicle;

a speed sensor that outputs pulse signals at an interval corresponding to a travel speed of the vehicle;

acceleration calculating means for calculating a travel acceleration of the vehicle based on the pulse signals outputted from the speed sensor; and

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using the azimuth change amount calculated based on the azimuth signal outputted by the azimuth sensor and a travel distance calculated based on the pulse signals outputted by the speed sensor,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals outputted from the speed sensor and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not outputted from the speed sensor when the vehicle travels, and the present position calculating means estimates the estimated travel distance based on the travel accelerations before and after the pulse-missing period;

a display portion including;

map data storing means for storing a map data including a road map data; and

map displaying means for displaying the road map data around the present position of the vehicle detected by the vehicle present position detection apparatus which is read from the map data storing means as a road map; and

route guidance means for recognizably displaying a route to a predetermined destination and the present position of the vehicle detected by the vehicle present position detection apparatus on the road map displayed by the map displaying means, and performing a route guidance in view of a relationship between the route to the predetermined destination and the present position of the vehicle.

19. A recording medium for recording a program being readable by a computer system, the program comprising:

acceleration calculating means for calculating a travel acceleration of a vehicle based on a pulse signals inputted at an interval corresponding to a travel speed of the vehicle; and

present position calculating means for calculating a present position of the vehicle by a dead-reckoning navigation calculation using an azimuth change amount calculated based on an azimuth signal and a travel distance calculated based on the pulse signals,

wherein the present position calculating means performs the dead-reckoning navigation calculation based on a corrected travel distance, which is the travel distance calculated based on the pulse signals and is corrected by adding an estimated travel distance during a pulse-missing period during which the pulse signals are not inputted thereto when the vehicle travels, and the present position calculating means estimates the estimated travel distance based on the travel accelerations before and after the pulse-missing period.