Patent ID: 7728719

Claim:
A single-transmitting and multi-receiving method of detecting obstacle, comprising acts of: (a) presetting a time period and multiple preset distances, wherein each present distances is defined between adjacent ultrasonic sensors mounted on a vehicle; (b) executing one transmitting and receiving procedure, wherein one of the ultrasonic sensors is controlled to output ultrasonic detecting signal and then all ultrasonic sensors are controlled in receiving status after the ultrasonic detecting signal is not output; (c) receiving an output signal of each ultrasonic sensor; (d) determining whether the ultrasonic sensor outputs the reflected detecting signal; wherein if a determining result is negative, go to the act (b), but if the determining result is positive, go to next act; (e) calculating distances of the reflected detecting signals; (f) reading the preset distances; and (g) calculating the shortest distance between a vehicle and an obstacle, wherein trigonometric equations are calculated by the distances from act (e) and the preset distances to obtain the shortest distance.