Lateral control of vehicle for lane following

(54) LATERAL CONTROL OF VEHICLE FOR LANE FOLLOWING

(75) Inventors: Shigeki Satoh; Kenya Uenuma, both of Kanagawa; Hiroshi Mouri, Yokohama; Hiroyuki Furusho; Masayasu Shimakage, both of Kanagawa, all of (JP)

(73) Assignee: Nissan Motor Co., Ltd., Yokohama (JP)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 09/628,686

(22) Filed: Jul. 28, 2000

(30) Foreign Application Priority Data

Aug. 2, 1999 (JP) 11-219171

(51) Int. CI.7 B60J 8/32; G06F 7/00

(52) U.S. CI 701/41; 340/439; 348/119;

180/168

(58) Field of Search 701/41, 23; 180/168,

180/167, 169, 141, 142; 340/439, 438, 435, 425.5; 348/119, 118; 342/113

(56) References Cited

U.S. PATENT DOCUMENTS

5,485,378 A * 1/1996 Franke et al 348/118

5,680,122 A * 10/1997 Mio 180/167

5,708,427 A * 1/1998 Bush 180/168

5,765,116 A 6/1998 Wilson-Jones et al 701/41

5,913,375 A 6/1999 Nishikawa 180/168

5,979,581 A 11/1999 Ravani et al 180/168

6,005,492 A * 12/1999 Tamura et al 180/169

6,091,833 A * 7/2000 Yasui et al 348/118

An apparatus for vehicle lane following in which a look ahead sensor including a CCD camera and an image processor detects a lane marking on the surface of a roadway. The image processor estimates a lateral displacement of a point at a preview distance in front of a vehicle from a target line. The target line is a line between lane markings defining a lane. An electric motor coupled to the steering mechanism is used to provide a bias (a torque input) to the steering, which may either assist or oppose to the steering torque from the driver. A steering controller is designed to assist the driver to maintain the vehicle's lane position by holding the vehicle at the target line using a biasing torque if the lane following is selected by the driver. In order to reflect the driver preference in the lane following, the controller collects a sufficient number of measures of the vehicle lateral displacement when the lane following is not selected. Based on the collected data, the controller updates the target line position. In the subsequent lane following, the driver is assisted to maintain the vehicle at this updated target line.

8 Claims, 6 Drawing Sheets