Distributed force sensor based on acoustic characteristics of elastic tube

The measurement of distributed force is highly demanded in various fields such as robotics. A flexible and nonmetal sensor configuration is often required in these applications. In this report, a distributed sensing method using an elastic tube, a small loud speaker and a microphone has been proposed, where the position of deformation along the tube can be determined from the acoustic characteristics of the tube. The basic properties of the distributed sensor were studied for a 1.2-m-long resin elastic tube of 10mm inner diameter. The distribution of deformation was estimated from the power spectrum measured at one end of the tube with white-noise excitation. The position of deformation was successfully detected from the Fourier transform of the power spectrum. It was also proved that two separate deformed parts were able to be discriminated.