Patent ID: 8224550

Claim:
A steering assist system comprising: traffic-line detecting means for detecting right and left traffic lines marked on a road; preceding-vehicle detecting means for detecting a preceding vehicle traveling ahead of a subject vehicle; traveling-target-point setting means for setting a traveling target point for traveling of the subject vehicle at a predetermined position in the preceding vehicle when the preceding vehicle is not within predetermined ranges from the right and left traffic lines, and for setting the traveling target point at a position offset from the predetermined position in the preceding vehicle toward the center of a traveling lane of the subject vehicle when the preceding vehicle is within the predetermined range of any one of the right and left traffic lines; and steering control means for controlling steering so that the subject vehicle passes over the traveling target point, wherein an offset amount of the traveling target point is calculated according to the following expression when the preceding vehicle is traveling near the right traffic line: O x = - RT ⁢ ⁢ 1 RT ⁢ ⁢ 2 · d pl ⁡ ( r ) - RT ⁢ ⁢ 1 , an offset amount is calculated according to the following expression when the preceding vehicle is traveling near the left traffic line: O x = - RT ⁢ ⁢ 1 RT ⁢ ⁢ 2 · d pl ⁡ ( l ) + RT ⁢ ⁢ 1 , ⁢ and where a right side in a width direction of the subject vehicle is a positive side, O x represents the offset amount, RT 1 represents the absolute value of an offset amount when the preceding vehicle is traveling on the respective right or left traffic line, RT 2 represents the absolute value of a distance from the respective right or left traffic line to an end of the predetermined range for said respective traffic line, and d pl (r) and d pl (l) respectively represent positions of the preceding vehicle relative to the right and left traffic lines in the width direction of the subject vehicle, and satisfy the following conditions: − RT 2≦ d pl ( r )≦ RT 2, and − RT 2 ≦d pl ( l )≦ RT 2.