Methods and apparatus for acoustic inspection of containers

摘要

Methods and apparatus for an acoustic source for directing acoustic energy to ensonify a container, a sensor to detect acoustic energy from the acoustic source affected by an object in the container without contacting the container, and a processing module to process the detected acoustic energy from the sensor to identify the object in the container.

主权项

1. A system for identifying at least one object in a container during an inspection of the container, the system configured to obtain measurements with respect to a recording surface on an exterior surface of the container during the inspection of the container, the system comprising:
at least one acoustic source for directing acoustic energy to penetrate at least one surface of the container and at least partially fill the container with acoustic energy during the inspection of the container,
wherein a frequency of the acoustic energy directed by the at least one acoustic source is selected to achieve a desired level of ensonification of the container, and the frequency of the acoustic energy is selected, at least in part, on a type of the container, andwherein the at least one acoustic source is positioned with respect to the container to achieve the desired level of ensonification of the container; a plurality of sensors to detect acoustic energy from the at least one acoustic source affected by the at least one object in the container without contacting the container during the inspection of the container,
wherein the sensors include one or more velocity vector sensors configured to measure temporal frequency differences of point scatterers that scatter the acoustic energy and spatially resolve the point scatterers at least in part from the measured temporal frequency differences,wherein at least one of the velocity vector sensors is provided as a laser vibrometer which detects a surface vibration on the recording surface, andwherein the at least one object includes a first object and a second different object, and the sensors are configured to detect acoustic energy from the acoustic source affected by the first object in the container and the second object in the container without contacting the container; and a processing module to process the detected acoustic energy, the detected surface vibration, and the spatially resolved point scatterers from the sensors to identify and to detect a location of the at least one object in the container,
wherein at least one of the velocity vector sensors is a second-order acoustic tensor sensor configured to measure displacement, velocity and acceleration vectors of the point scatterers with respect to the recording surface and scalar acoustic pressure appearing at one or more points on the recording surface,wherein the point scatterers are further spatially resolved by the measured displacement, velocity and acceleration vectors of the point scatterers and the measured scalar acoustic pressure,wherein the location of the at least one object in the container is determined by interpolating select data from the detected acoustic energy, the detected surface vibration, and the spatially resolved point scatterers,wherein the select data is interpolated to find energy peaks which are indicative of the location of the at least one object, andwherein the processing module is configured to process the detected acoustic energy, the detected surface vibrations and the spatially resolved point scatterers from the plurality of sensors to identify the first object based, at least in part, on an acoustic profile characteristic of the first object, and to identify the second object, at least in part, on an acoustic profile characteristic of the second object.