Perception and characterization of materials using signal processing techniques

In this paper, we develop a methodology and a conceptual framework in which manipulations are undertaken for perceiving and characterizing materials. Within this framework, we distinguish different materials (unknown environm ents) by actively contacting and testing them, and by analyzing the resulti ng sounds using a microphone. For this implementation, we identify sensor-d erived measures that are diagnostic of a material's properties, and use the se measures to categorize the objects (or unknown environments) in their di fferent material class. The parameter of characterization is the internal a ngle of friction of the materials. This parameter is determined by the rela tion of strain and stress properties. Using this theoretical approach and t he experimental results, we conclude that the statement of shape-invariance of materials is critical and invalid in real cases.