Method for estimating position of objective obstacle for vehicle

A method for estimating a position of an objective obstacle, in a vehicle equipped with a distance measuring unit which comprises a transmitting and receiving section capable of transmitting a signal toward the objective obstacle and receiving a reflected signal from the objective obstacle, and a calculating section for calculating a distance between the subject vehicle and the objective obstacle on the basis of a time between the transmission and the reception of the signals, said method comprising the steps of:

• detecting the objective obstacle along a widthwise direction of the subject vehicle by the distance measuring unit;
• developing detection data, detected by said distance measuring unit, on X and Y coordinates in which the widthwise direction of the subject vehicle is represented by an X axis;
• the longitudinal direction of the subject vehicle is represented by a Y axis, and the position of the subject vehicle is defined as an origin;
• labeling each of obstacle data in such manner that the same labels are affixed to obstacle data which are in proximity to one another on said coordinates;
• calculating the amount and direction of movement for every label on the basis of the last data and current data;
• calculating a relative speed for every label relative to the subject vehicle by dividing the amount of movement by a sampling time;
• and
• estimating the position of the objective obstacle after a lapse of a predetermined time on the basis of a relative speed vector determined from said relative speed and said direction of movement.