Driving assist controller for vehicle

1. A driving assist controller for a vehicle, comprising:

a visibility estimation unit that estimates a visibility of a driver based on a farthest distance along a lane line detected at a contrast value higher than an average contrast value of human vision which is set in advance based on testing data and recognizes the visibility of the driver in order to understand a state of the visibility of the driver due to an influence of an environment in a direction of travel;

a visibility degradation ratio calculation unit that calculates a visibility degradation ratio based on a temporal change amount of the visibility of the driver in each period of time estimated by the visibility estimation unit; and

a first control unit that compares the visibility degradation ratio with predetermined values according to the vehicle speed and detects whether the visibility degradation ratio exceeds the predetermined values,

wherein the first control unit outputs a detection of the visibility degradation ratio to a second control unit that controls the vehicle based on the visibility of the driver.

2. The driving assist controller for a vehicle according to claim 1 , further comprising

an environment recognition unit that detects lane line information on a travel lane ahead of the vehicle on the basis of image information and extrapolates future lane line information,

wherein the visibility estimation unit estimates the visibility of the driver on a basis of the lane line information and the extrapolated future lane line information.

3. The driving assist controller for a vehicle according to claim 1 , wherein

the second control unit comprises at least a warning control unit, and

the warning control unit compares the temporal change amount of the visibility with a preset first threshold to determine whether to warn the driver.

4. The driving assist controller for a vehicle according to claim 1 , wherein

the second control unit comprises at least an antilock brake control unit actuated by an allowed slip ratio and preventing a wheel from locking during braking; and

the antilock brake control unit compares the temporal change amount of the visibility with a preset second threshold and changes the allowed slip ratio.

5. A driving assist controller for a vehicle, comprising:

a visibility estimation unit that estimates visibility of a driver;

a visibility change amount calculation unit that calculates a temporal change amount of the visibility; and

a control unit that actuates a second control unit on a basis of the temporal change amount of the visibility,

wherein:

the second control unit comprises at least a skid preventing control unit that generates a yaw momentum in the vehicle and prevents the vehicle from skidding; and

the skid preventing control unit compares the temporal change amount of the visibility with a preset third threshold and changes at least one of a generation timing of the yaw momentum and an intensity of the generated yaw momentum.

6. The driving assist controller for a vehicle according to claim 1 , wherein

the second control unit comprises at least a brake assist control unit that assists a braking force created by the driver; and

the brake assist control unit compares the temporal Change amount of the visibility with a preset fourth threshold and selectively changes an assist brake addition timing according to the comparison.

7. The driving assist controller for a vehicle according to claim 1 , wherein

the second control unit comprises at least a deceleration control unit that applies a calculated target deceleration to the vehicle and decelerates the vehicle; and

the deceleration control unit compares the temporal Change amount of the visibility with a preset fifth threshold, selectively applies the calculated target deceleration to the vehicle according to the comparison, and decelerates the vehicle.

8. The driving assist controller for a vehicle according to claim 7 , wherein the target deceleration is calculated on a basis of the vehicle speed and the preset fifth threshold.

9. The driving assist controller for a vehicle according to claim 3 , wherein the preset first threshold is set to be changeable according to a vehicle speed.

10. The driving assist controller for a vehicle according to claim 1 , wherein the temporal change amount of the visibility of the driver comprises a ratio of a previous visibility of the driver and a current visibility of the driver.

11. The driving assist controller for a vehicle according to claim 1 , wherein the temporal change amount of the visibility of the driver is a ratio of a previous visibility of the driver and a current visibility of the driver such that a positive ratio indicates a degradation of the visibility of the driver and a negative ratio indicates an improvement of the visibility of the driver.

12. The driving assist controller for a vehicle according to claim 10 , wherein a previous visibility of the driver occurs a predetermined time before a current visibility of the driver.

13. The driving assist controller for a vehicle according to claim 10 , wherein the previous visibility of the driver occurs a predetermined time before the current visibility of the driver,

wherein the ratio is calculated based on the predetermined time.

14. The driving assist controller for a vehicle according to claim 11 , wherein a previous visibility of the driver occurs a predetermined time before a current visibility of the driver.