DRIVE ASSIST APPARATUS AND DRIVE ASSIST SYSTEM

• US 20120323406A1
• Filed: 06/12/2012
• Published: 12/20/2012
• Est. Priority Date: 06/17/2011
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Yamashiro, Takahisa
• Granted Patent: US 8,885,469 B2
• Time in Patent Office: Days
• US Class Current: 701/2
• CPC Class Codes: G08G 1/161 Decentralised systems, e.g. inter-vehicle communication
• CPC Class Codes: G08G 1/22 Platooning, i.e. convoy of communicating vehicles
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks

Abstract

When prediction information is newly acquired, a degree of the difference between a predicted via-point at a current time point is determined based on already transmitted past prediction information and a current position contained in the newly acquired prediction information. Then, it is determined whether the determined degree of the difference is a predetermined value or more. When the degree of the difference is determined to be the predetermined value or more, the newly acquired prediction information is transmitted.

Claims

1. A drive assist apparatus in a vehicle, the driving assist apparatus having a prediction information acquisition section that successively acquires prediction information at a time point from an in-vehicle information detection portion, the prediction information being enabled to be transmitted via inter-vehicle communications,

the drive assist apparatus comprising:

a via-point prediction section to obtain a predicted via-point of the vehicle where the vehicle exists from a time point to a future time point on a basis of prediction information at the time point acquired by the prediction information acquisition section, the prediction information at the time point containing at least a position at which the vehicle exists at the time point;

a difference determination section that,

when the prediction information acquisition section newly acquires second prediction information at a second time point that is later than a first time point,

obtains a difference between

(i) a predicted via-point of the vehicle predicted at the second time point between the first time point to the future time point on a basis of first prediction information at the first time point, the first prediction information at the first time point being acquired at the first time point by the prediction information acquisition section and being already transmitted via the inter-vehicle communications and

(ii) a position, at which the vehicle exists at the second time point, obtained on a basis of the second prediction information at the second time point,

the difference determination section further determining whether the obtained difference is a predetermined value or more; and

a transmission determination section that

determines that the second prediction information newly acquired is transmitted when the difference determination section determines that the difference is the predetermined value or more, and

determines that the second prediction information newly acquired is not transmitted when the difference determination section determines that the difference is not the predetermined value or more.

2. The drive assist apparatus according to claim 1, being configured to communicate with a communications portion that is provided in a different vehicle, via the inter-vehicle communications using radio communications.

3. The drive assist apparatus according to claim 2, further comprising:

a communication target identification section to identify a communications portion in a different vehicle with which the inter-vehicle communications are enabled, on a basis of reception of information from the communications portion in the different vehicle,

wherein;

in cases that the communications portion in the different vehicle is identified by the communication target identification section newly after the first prediction information at the first time point is transmitted via the inter-vehicle communications,

the second prediction information at the second information newly acquired by the prediction information acquisition section is transmitted even when the transmission determination section determines that the second prediction information is not transmitted.

4. The drive assist apparatus according to claim 2, wherein:

the communications portion in the different vehicle serves as a different drive assist apparatus that has a same function as a function of the drive assist apparatus in the vehicle; and

when the different vehicle mounting the different drive assist apparatus is a leading vehicle nearest to the vehicle, the vehicle is caused to trail the leading vehicle on a basis of prediction information that is received from the communications portion in the leading vehicle.

5. The drive assist apparatus according to claim 4, being enabled to receive prediction information that is transmitted via the inter-vehicle communications from each of a plurality of the different drive assist apparatuses in a plurality of the leading vehicles,

the drive assist apparatus further comprising:

a track prediction section that predicts a track of the vehicle from predicted via-points of the vehicle successively obtained by the via-point prediction section;

a deviation point search section that performs a search for a deviation point where the leading vehicle starts to deviate from the track of the vehicle based on (i) a position of each of the leading vehicles contained in the prediction information of the each of the leading vehicles and (ii) the track of the vehicle predicted by the track prediction section; and

an effective range determination section that determines, when the deviation point where the leading vehicle starts to deviate from the track of the vehicle is obtained by the deviation point search section, an effective range of the prediction information on a basis of the deviation point that is obtained by the search performed by the deviation point search section,

the effective range of the prediction information being a range where the prediction information transmitted from the vehicle is effective in obtaining a predicted via-point of the vehicle,

wherein;

the effective range of the prediction information determined by the effective range determination section is also transmitted when the prediction information is transmitted from the vehicle via the inter-vehicle communications.

6. The drive assist apparatus according to claim 5, wherein:

in cases where the effective range of the prediction information determined by the effective range determination section changes by a predetermined value or more after the first prediction information is transmitted via the inter-vehicle communications, even when the transmission determination section determines that the second prediction information is not transmitted, the second prediction information newly acquired by the prediction information acquisition section is transmitted.

7. The drive assist apparatus according to claim 5, wherein:

when the prediction information and the effective range of the prediction information are received from the different drive assist apparatus mounted to the leading vehicle nearest to the vehicle,

the vehicle is caused to trail the leading vehicle with a first inter-vehicle distance to the leading vehicle on a basis of the prediction information received from the different drive assist apparatus, whereas the vehicle is caused to trail the leading vehicle with a second inter-vehicle distance to the leading vehicle longer than the first inter-vehicle distance when a distance needing to go beyond the effective range becomes a predetermined value or below.

8. The drive assist apparatus according to claim 5, wherein:

when the deviation point search section performs the search for the deviation point where the leading vehicle starts to deviate from the track of the vehicle,

the effective range determination section predicts a time point for the vehicle to reach the deviation point, and determines the predicted time point as the effective range.

9. The drive assist apparatus according to claim 5, wherein:

when the deviation point search section performs the search for the deviation point where the leading vehicle starts to deviate from the track of the vehicle,

the effective range determination section determines, as the effective range, positional information indicating the deviation point obtained by the search performed by the deviation point search section.

10. The drive assist apparatus according to claim 4, being enabled to receive prediction information that is transmitted via the inter-vehicle communications from each of a plurality of the different drive assist apparatuses in a plurality of the leading vehicles,

wherein:

the via-point prediction section determines a predicted via-point of the vehicle on a basis of (i) prediction information acquired by the prediction information acquisition section of the vehicle and (ii) a position of at least one of the leading vehicles contained in prediction information received from the different drive assist apparatus of the at least one of the leading vehicles.

11. The drive assist apparatus according to claim 10, further comprising:

a track prediction section that predicts a track of the vehicle from predicted via-points of the vehicle successively determined by the via-point prediction section; and

a deviation point search section that performs a search for a point where the leading vehicle starts to deviate from the track of the vehicle, on a basis of (i) positions of the leading vehicles contained in the prediction information of the leading vehicles and (ii) the track of the vehicle predicted by the track prediction section,

wherein;

in a range between (i) the vehicle and (ii) the deviation point where the leading vehicle starts to deviate from the track of the vehicle, a predicted via-point of the vehicle is obtained on a basis of prediction information acquired by the prediction information acquisition section of the vehicle; and

in a range beyond the deviation point where the leading vehicle starts to deviate from the track of the vehicle, a predicted via-point of the vehicle is obtained as the position of the leading vehicle contained in prediction information received from the different drive assist apparatus of the leading vehicle.

12. A drive assist system comprising:

the drive assist apparatus according to claim 1 mounted to each of a plurality of vehicles.

13. A program product stored in a non-transitory computer readable storage medium comprising computer-implemented instructions for execution by a computer, the instructions being for a drive assist apparatus in a vehicle having (i) a prediction information acquisition section that successively acquires prediction information at a time point from an information detection portion in the vehicle, and (ii) a communications portion that is enabled to communicate with a plurality of different vehicles via inter-vehicle communications, the prediction information allowing obtainment of a plurality of predicted via-points where the vehicle exists from the time point to a future time point,

the product comprising instructions of:

acquiring first prediction information at a first time point from the information detection portion;

transmitting the first prediction information at the first time point via the inter-vehicle communications;

acquiring second prediction information at a second time point from the information detection portion, the second time point being later than the first time point;

obtaining an actual second-time-point position, at which the vehicle actually exists at the second time point, based on the second prediction information at the second time point;

obtaining a predicted second-time-point via-point, at which the vehicle is predicted to exit at the second time point, based on the first prediction information at the first time;

obtaining a difference between (i) the actual second-time-point position of the vehicle, and (ii) the predicted second-time-point via-point of the vehicle;

determining whether the difference is a predetermined value or more; and

determining that the second prediction information at the second time point is transmitted when the difference is determined to be the predetermined value or more, whereas determining that the second prediction information at the second time point is not transmitted when the difference is determined not to be the predetermined value or more.