Process for the recognition and separation of useful and interfering echoes in the received signals of distance sensors which operate in accordance with the pulse-echo principle

A method for the recognition and separation of useful and interfering echoes in a received signal of a pulse-echo distance sensor, said method comprising the steps of:

• detecting maxima in said received signal and associating each maxima with an echo;
• identifying a form factor with each echo characterizing a form of that echo, and storing the form factors for the respective echoes;
• identifying an amplitude and a time of occurrence for each maximum, and storing the respective amplitude and time of occurrence for all of said maxima;
• measuring a difference between the amplitudes of the respective maxima and expected amplitude values;
• measuring a difference between the time of occurrence of each maximum and expected time of occurrence values;
• measuring a difference between the form factor for each echo and expected form factor values;
• assigning a probability to each echo as to whether that echo comprises a multiple echo by evaluating each of the amplitude, time of occurrence and form factor differences with a smaller difference resulting in an increased probability that said echo comprises a multiple echo;
• and
• assigning a probability to each echo as to whether that echo comprises an interfering echo with the probability that said echo comprises an interfering echo being greater as the probability of said echo comprising a multiple echo increases.