Driving assist method, driving assist apparatus, and driving assist system

1. A driving assist method comprising:

detecting positional information of multiple positions of a first vehicle with a global navigation satellite system;

storing the detected positional information;

detecting a curve along which the first vehicle has already traveled in accordance with the multiple positions included in the stored positional information;

generating curve information including road information and a curvature of the curve at the detected curve;

transmitting the generated curve information from the first vehicle to surroundings of the first vehicle after the first vehicle passes the curve;

receiving the curve information by a second vehicle;

determining a timing to provide the curve information in accordance with the received curve information;

providing the curve information at the determined timing to the second vehicle; and

evaluating whether or not the second vehicle travels along the curve in response to the received curve information, and the preventing providing the curve information to the second vehicle when the second vehicle is not traveling along the curve.

2. The driving assist method according to claim 1 , further comprising:

determining a curve entering speed in accordance with the curvature of the curve included in the curve information; wherein

the determining the timing determines the timing in accordance with the curve information and the speed of the second vehicle, and the providing the curve information provides the curve entering speed in accordance with the timing.

3. The driving assist method according to claim 2 , further comprising:

comparing a speed of the second vehicle with the curve entering speed; and

calculating a deceleration starting position in accordance with a position of the second vehicle and the curve information when the speed of the second vehicle is larger than the curve entering speed; wherein

the providing the curve information includes providing deceleration instructing information when the second vehicle reaches the deceleration starting position.

4. The driving assist method according to claim 2 , further comprising:

correcting the determined curve entering speed in accordance with the road information included in the curve information.

5. A vehicle driving assist apparatus comprising:

a positional information detector that detects positional information of multiple positions of a transmitting vehicle;

a positional information storage that stores the detected positional information;

a curve detector that detects a curve along which the transmitting vehicle has already traveled in accordance with the multiple positions included in the stored positional information;

a curve information generator that generates curve information on the detected curve, the curve information including road information and a curvature of the curve;

a transmitter that transmits the generated curve information;

an entering speed calculator that determines a curve entering speed in accordance with the curvature of the curve included in the curve information; and

a speed comparator that compares a speed of a receiving vehicle with the curve entering speed; wherein

the positional information detector includes a global navigation satellite system; and

when the speed of the receiving vehicle is equal to or smaller than the curve entering speed, the transmitter transmits the curve information at a time when the receiving vehicle reaches a guidance position spaced away from the curve by a predetermined distance.

6. A driving assist system comprising:

a positional information detector that detects positional information of multiple positions of a transmitting vehicle;

a positional information storage that stores the detected positional information;

a curve detector that detects a curve along which the transmitting vehicle has already traveled in accordance with the multiple positions included in the stored positional information;

a curve information generator that generates road information and curve information on the detected curve;

a transmitter that transmits the generated curve information; and

a driving assist apparatus including:

a receiver that receives curve information including road information and a curvature of a curve;

a timing calculator that determines a timing to provide the curve information in accordance with the received curve information; and

an information output that provides the curve information at the determined timing;

a server that stores the transmitted curve information and transmits the stored curve information to the driving assist apparatus on a receiving vehicle; wherein

the positional information detector includes a global navigation satellite system; and

the server is not mounted on either one of the transmitting vehicle and the receiving vehicle.

7. The driving assist system according to claim 6 , wherein

the server acquires positional information on the transmitting vehicle and the receiving vehicle, and transmits the stored curve information to the driving assist apparatus of the receiving vehicle traveling toward the curve in response to the curve information.

8. The driving assist method according to claim 1 , wherein

the step of generating the road information includes determining a road condition through image processing based on an image of a surface of the road in the curve taken by an image sensor; and

the road information includes at least one of:

first information that indicates whether the road is a paved road or a dirt road;

second information that indicates whether a condition of the road is a dry condition, a wet condition, or a snowy condition; and

third information that indicates a friction coefficient of the road.

9. The driving assist method according to claim 2 , further comprising:

comparing a speed of the second vehicle with the curve entering speed; wherein

when the speed of the second vehicle is equal to or smaller than the curve entering speed, the step of determining the timing determines to provide the curve information at a time when the second vehicle reaches a guidance position spaced away from the curve by a predetermined distance.

10. The driving assist method according to claim 9 , wherein

the guidance position is variable based on the road information included in the curve information.

11. The driving assist method according to claim 4 , wherein

when the road information indicates the road is a wet condition or a snowy condition, the correcting the determined curve entering speed decreases the curve entry speed by a greater rate than when the road information indicates the road is a dry condition; and

when the road information indicates the road is a dirt road, the correcting the determined curve entering speed decreases the curve entry speed by a greater rate than when the road information indicates the road is a paved road.