Obstacle detection system and method using distance sensor

An obstacle detection system for a rear autonomous emergency braking (R-AEB) system, the obstacle detection system comprising:

• a first distance sensor installed in a vehicle and having a first field of view of a rear region behind a vehicle, the first distance sensor configured to sense a first distance to a first obstacle positioned within the first field of view as the vehicle moves rearwardly, the first obstacle being stationary;
• a second distance sensor installed in the vehicle, spaced apart from the first distance sensor in a lateral direction of the vehicle and having a second field of view of the rear region behind the vehicle that partially overlaps the first field of view to define an overlapping field of view, the second distance sensor configured to sense a second distance to a second obstacle positioned within the second field of view as the vehicle moves rearwardly, the second obstacle being stationary;
• an auxiliary sensor installed in the vehicle and positioned between the first and second distance sensors in the lateral direction of the vehicle, the auxiliary sensor having a third field of view that is within the overlapping field, the auxiliary sensor configured to sense a third distance to an obstacle at least partially positioned within the third field of view as the vehicle moves rearwardly;
• and
• a detection unit configured to determine whether the first obstacle and the second obstacle are a same obstacle positioned within the overlapping field of view or different obstacles positioned outside the overlapping field of view based on the first distance to the first obstacle, the second distance to the second obstacle, and the third distance to the obstacle in the third field of view,
• wherein the detection unit is further configured to:
• estimate a first position of the first obstacle using a trigonometric method based on the first distance and the third distance detected by the first sensor and the auxiliary distance sensor, respectively;
• estimate a second position of the second obstacle using the trigonometric method based on the second distance and the third distance detected by the second sensor and the auxiliary distance sensor, respectively;
• and
• determine whether the first obstacle and the second obstacle are the same obstacle within the overlapping field of view based on the estimated first and second positions,
• wherein the first and second distance sensors are each an ultrasonic sensor or a radar sensor having an antenna configured to sense the first and second distances to the obstacle, respectively,
• wherein the auxiliary sensor is a camera sensor or an infrared sensor, and the third field of view is narrower than the first and the second field of view,
• wherein, when the detection unit determines that the first obstacle and the second obstacle are different obstacles positioned outside of the overlapping field, the detection unit ignores the first obstacle and the second obstacle for purposes of the R-AEB, and
• wherein, when the detection unit determines that the first obstacle and the second obstacle are the same obstacle positioned within the overlapping field,
• the detection unit alerts the R-AEB to brake the vehicle.