Patent ID: 6202034
Filing Date: 2001-03-13
Classification: G01S

Abstract:
A method of measuring distance to a target using ultrasonic sound waves, said method comprising the steps of:generating an electrical drive signal having a series of signal pulses at an ultrasonic frequency;applying said drive signal as an input to an ultrasonic transducer to produce ultrasonic sound waves;transmitting said ultrasonic sound waves in a desired transmission path;receiving ultrasonic sound waves reflected from a target in the transmission path of said transmitted sound waves;converting said received reflected sound waves to an electrical signal;determining a middle time value of the drive signal;determining a middle time value of the received electrical signal;determining a time period from the middle time value of the received electrical signal to the middle time value of the drive signal; anddetermining distance to the target as a function of one-half of said time period and speed of travel of said ultrasonic sound waves.