A Simple Identification Method for Object Shapes and Materials Using an Ultrasonic Sensor Array

From the viewpoint of environmental protection, the recycling of wastes becomes ever more important. In such a field, there is the manner of recycling or reuse, we need to develop a simple technique on advertising to promote recycling and reuse based on the local autonomy. Especially, the field of sorting for reuse requires a simple sensor system that identifies the materials, shape and size of an object without contact with the target. Here, we propose a new identification system using an ultrasonic sensor array and neural networks. The method sorts by the shape and the material of an object based on ultrasonic pressure distribution and acoustic impedance. We have done some experiments with a prototype sensor system. The experimental results showed the practical applicability of the identification method in a shapes and materials sorting system