Guidance method and guidance device

1 . A guidance method, comprising:

obtaining an image and a speed, wherein the image corresponds to a field of view in a traveling direction of a vehicle, and the speed is a movement speed of the vehicle;

identifying a road block in the image, wherein the road block is an image block corresponding to a road;

converting a lane curvature corresponding to the road block into a curvature factor according to the speed, wherein the lane curvature corresponds to a curvature of the road block;

generating a guidance graphic based on the curvature factor; and

presenting the guidance graphic.

2 . The guidance method according to claim 1 , wherein the step of converting the lane curvature corresponding to the road block into the curvature factor according to the speed comprises:

determining a curvature difference between a reference curvature and the lane curvature;

determining a speed ratio of the speed to a reference speed; and

determining the curvature factor based on the curvature difference and the speed ratio.

3 . The guidance method according to claim 2 , wherein the step of determining the curvature factor based on the curvature difference and the speed ratio comprises:

in response to the reference curvature being greater than an absolute value of the lane curvature, calculating a product of the curvature difference, the speed ratio, and a reciprocal of a proportional coefficient as the curvature factor; and

in response to the reference curvature not being greater than the absolute value of the lane curvature, setting the curvature factor to an initial value.

4 . The guidance method according to claim 1 , further comprising:

determining the speed based on a pitch of the road and a sensed speed of the vehicle.

5 . The guidance method according to claim 1 , wherein the step of generating the guidance graphic based on the curvature factor comprises:

altering a position of at least one of a plurality of reference points of a reference graphic based on the curvature factor, wherein connections between the plurality of reference points form the reference graphic.

6 . The guidance method according to claim 5 , wherein the plurality of reference points comprises a first point, and the step of altering the position of the at least one of the plurality of reference points of the reference graphic based on the curvature factor comprises:

displacing the first point from an original position thereof based on the curvature factor, wherein the first point at a new position is combined with the other points of the plurality of reference points to form the guidance graphic.

7 . The guidance method according to claim 6 , wherein the step of displacing the first point from the original position thereof based on the curvature factor comprises:

displacing the first point horizontally, wherein

in response to the larger curvature factor, a horizontal distance by which the first point is displaced from the original position thereof increases; and

in response to the smaller curvature factor, the horizontal distance by which the first point is displaced from the original position thereof decreases.

8 . The guidance method according to claim 5 , further comprising:

generating an upper line using a Bézier curve with M 1 points; and

generating a lower line using the Bézier curve with M 1 - 1 points, wherein the upper line and the lower line form the guidance graphic.

9 . The guidance method according to claim 5 , further comprising:

generating a left line using a Bézier curve with M 2 points; and

generating a right line using the Bézier curve with the M 2 points, wherein the left line and the right line form the guidance graphic.

10 . The guidance method according to claim 1 , further comprising:

changing an overall length of the guidance graphic based on the speed.

11 . A guidance device, comprising:

a storage, storing a program code; and

a processor, coupled to the storage, and loading the program code to:

obtain an image and a speed, wherein the image corresponds to a field of view in a traveling direction of a vehicle, and the speed is a movement speed of the vehicle;

identify a road block in the image, wherein the road block is an image block corresponding to a road;

convert a lane curvature corresponding to the road block into a curvature factor according to the speed, wherein the lane curvature corresponds to a curvature of the road block;

generate a guidance graphic based on the curvature factor; and

present the guidance graphic.

12 . The guidance device according to claim 11 , wherein the processor is further configured to:

determine a curvature difference between a reference curvature and the lane curvature;

determine a speed ratio of the speed to a reference speed; and

determine the curvature factor based on the curvature difference and the speed ratio.

13 . The guidance device according to claim 12 , wherein the processor is further configured to:

in response to the reference curvature being greater than an absolute value of the lane curvature, calculate a product of the curvature difference, the speed ratio, and a reciprocal of a proportional coefficient as the curvature factor; and

in response to the reference curvature not being greater than the absolute value of the lane curvature, set the curvature factor to an initial value.

14 . The guidance device according to claim 11 , wherein the processor is further configured to:

determine the speed based on a pitch of the road and a sensed speed of the vehicle.

15 . The guidance device according to claim 11 , wherein the processor is further configured to:

alter a position of at least one of a plurality of reference points of a reference graphic based on the curvature factor, wherein connections between the plurality of reference points form the reference graphic.

16 . The guidance device according to claim 15 , wherein the plurality of reference points comprises a first point, and the processor is further configured to:

displace the first point from an original position thereof based on the curvature factor, wherein the first point at a new position is combined with the other points of the plurality of reference points to form the guidance graphic.

17 . The guidance device according to claim 16 , wherein the processor is further configured to:

displace the first point horizontally, wherein

in response to the larger curvature factor, a horizontal distance by which the first point is displaced from the original position thereof increases; and

in response to the smaller curvature factor, the horizontal distance by which the first point is displaced from the original position thereof decreases.

18 . The guidance device according to claim 15 , wherein the processor is further configured to:

generate an upper line using a Bézier curve with M 1 points; and

generate a lower line using the Bézier curve with M 1 - 1 points, wherein the upper line and the lower line form the guidance graphic.

19 . The guidance device according to claim 15 , wherein the processor is further configured to:

generate a left line using a Bézier curve with M 2 points; and

generate a right line using the Bézier curve with the M 2 points, wherein the left line and the right line form the guidance graphic.

20 . The guidance device according to claim 11 , wherein the processor is further configured to:

change an overall length of the guidance graphic based on the speed.