Method for eliminating sound reflection interference in ultrasonic location

The invention provides a method for eliminating sound reflection interference in ultrasonic location. The method is characterized by comprising the following steps of: firstly, respectively performing forward low-speed operation and roughly-related operation by taking the maximum value points of a reference signal and an ultrasonic receiving signal as a datum point to determinate the existence of sound reflection interference; secondly, performing an optimized dynamic threshold algorithm on the ultrasonic receiving signal to separate an ultrasonic direct signal after difference quotient from a sound reflection interference signal after difference quotient and extract the preliminary time delay of the ultrasonic direct signal; and finally, performing a finely-related operation within a local range based on the preliminary time delay to obtain precision time delay. The method has the advantages that: 1, the existence of the sound reflection interference can be judged due to the adoption of the roughly-related technology, and the operation quantity of the algorithm can be further reduced on the premise of exact judgment; 2, the sound reflection interference in the ultrasonic location can be effectively eliminated by adopting the optimized dynamic threshold algorithm; and 3, the finely-related operation is performed based on signal wave shape which is converted on the basis of the optimized dynamic threshold algorithm, so that the method is small in operation quantity and high in time delay extraction precision.