The system has three ultrasonic sensors and an ultrasonic emitter.Three sensors are located at different apex of a right triangle and an ultrasonic emitter is located at center of hypotenuse.

• 此种超音波感测系统是利用三个超音波接收器，安排成直角等腰三角形排列，并且在直角三角形斜边的中央放置一个超音波发射器。