SYSTEM FOR MEASURING POSITION OF AN OBJECT USING ELECTRONIC OR ULTRASONIC DEVICES WHERE THE OBJECT CONTAINS A REFERENCE REFLECTOR FOR TEMPERATURE COMPENSATION

摘要

A system for measuring the position of a moving object (4; 304) including transceiver means (1-3; 301) for sending signals to and receiving signals reflected from both a moving object surface (5; 305) and a reference object surface (6; 306) maintaining a known, fixed distance from the moving object surface, wherein by processing the signals sent and received, the position of the moving object can be determined while the effects of temperature on the speed of sound, frequency changes, false echoes and erroneous signals are minimized or eliminated.