Lane keeping assist system

• US 8,095,266 B2
• Filed: 11/24/2008
• Issued: 01/10/2012
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Kim, Hoi Won
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US12/276,615
• Publication Number:
  US 20090153360A1
• Time in Patent Office: 1,142 Days
• Field of Search: 701/36, 701/41, 701/42, 701/96, 701117-119, 701300-302, 340/905, 340/907, 340933-943, 342/27, 342/28, 342/69, 342/89, 342/90, 342/91, 342 98-101, 342109-117, 342/128
• US Class Current: 701/36
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

A lane keeping assist system (LKAS) is equipped with a compensator capable of solving the problem in which video data, which is measured by a video sensor, the processing speed of which is lower than the data processing speed of the LKAS, is repeatedly used, thereby improving the kinematic characteristics of a vehicle and lane-keeping control performance.

Claims

1. A lane-keeping assist system (LKAS) for a vehicle, comprising:

a video sensor unit for capturing video image or images outside of the vehicle and measuring location information of the vehicle and a curvature (ρ

_p) of a lane with respect to a measuring point;

a sensor unit for measuring a variable value or values related to one or more kinematic characteristics of the vehicle;

a control unit for performing lane keeping control based on the location information, the lane curvature and the variable value or values related to the kinematic characteristics; and

a compensation unit for estimating a deviation angle (θ

_p) and a deviation distance (y_p) based on data from the video sensor unit, the sensor unit and the control unit in a period that is a control data processing period of the control unit but is not a measurement period of the video sensor unit, and transmitting the estimated values to the control unit.

2. The LKAS as set forth in claim 1, wherein the location information of the vehicle measured by the video sensor unit is a deviation angle (θ

_p) and a deviation distance (y_p) of the vehicle with respect to the measuring point.

3. The LKAS as set forth in claim 1, wherein the variable value related to the kinematic characteristics is a velocity (V) of the vehicle, a yaw rate (γ

), a required forward angle (δ

_f) measured by the sensor unit 20, or a combination thereof.

4. The LKAS as set forth in claim 1, wherein the data transmitted from the video sensor unit, the sensor unit and the control unit 40 to the compensation unit comprises at least one selected from the group consisting of a deviation angle (θ

_p) and a deviation distance (y_p) measured by the video sensor unit 10, a velocity (V) of the vehicle and a yaw rate (γ

) measured by the sensor unit, and a lateral velocity (ν

) estimated by the control unit.

5. The LKAS as set forth in claim 1, wherein the deviation distance estimated by the compensation unit is obtained by the equation y_p=∫

(ν

+L_p×

γ

+V×

θ

_p)dt where ν

is a lateral velocity, L_p is a distance between a measuring point of the video sensor and a central axis of the vehicle, γ

is a yaw rate of the vehicle, V is a velocity of the vehicle and the estimated deviation angle by the compensation unit is obtained by the equation θ

_p=∫

(γ

−

V×

ρ

)dt where ρ

is a curvature of a road.

6. The LKAS as set forth in any one of claims 1, wherein the control unit calculates a torque value T_m of a steering motor of the vehicle using the following state equation and performs control so that the vehicle is kept in a target lane: