Improved TOF determination algorithms for robust ultrasonic positioning of smart tools

This paper investigates the design criteria for an ultrasound positioning system used in smart tool applications. A novel range-finding system based upon low cost, ease of implementation, and an automatic gain controller (AGC) is developed. We also design several signal processing algorithms for this system, including an amplitude threshold method (ATM), a frequency threshold method (FTM), and a cross correlation method (CCM). These methods are compared in one dimension based upon precision and processing time. Our results show promising results for a high-accuracy, low-cost, and flexible solution for smart tool applications. For smart tool applications which require 1mm precision and target speeds of 0.25m/s, we recommend the CCM, which strikes a balance between processing time and accuracy. We discuss methods for improving these algorithms.