Robot-assisted acoustic inspection of infrastructures - cooperative hammer sounding inspection

This work presents a human-robot cooperative approach for infrastructure inspection. The goal is to create a robot that assists the human inspector during hammer sounding inspections. Hammer sounding is a frequently used inspection technique that detects invisible defects under the surface of concrete by striking the surface with a hammer and listening the resulting sound. The conventional hammer sounding inspection is time-consuming, and there is no convenient way to represent exhaustively the test results. The proposed approach solves these two problems by having an assistant robot following the inspector, and always being able to look at the hammer impact position. The assistant robot accurately estimates the position of the impact in real-time and creates a detailed representation of the test results. Experimental results show the process for creating the detailed inspection report. The accuracy of the human-robot cooperative approach is evaluated for a real world application. The average error of the impact point estimation was 32 millimeters and the standard deviation was 30 millimeters.