Investigation of Laplace's Velocity Equation for Temperature Compensation in Pulse-Echo Time of Flight Ultrasonic Ranging

摘要

This paper discusses and analyzes some methods of temperature compensation in Ultrasonic ranging systems. Ultrasonic ranging systems utilize short bursts of frequency signals for measurement of distances. The measurement of distances by ultrasonic ranging systems is characterized by the problem of the errors that arise due to variation of the speed of sound with change of temperature. In this work, we investigate Laplace's velocity equation using empirical methods, for a temperature compensation system capable of tracking resonant frequency drifts of ultrasonic transducers caused by variation in temperature. The results obtained for percentage deviation in distance with temperature experiment are compared with the theoretical values calculated by Dennis Bonn in his paper on 'environmental effects on the speed of sound'. The empirical equation developed simplifies calculations of corrected distance using such an ultrasonic ranging system. The time resolution required by the system determines the minimum distance resolution. This time resolution can be reduced using this equation by application of an appropriate algorithm.