Abstract
The authors previously proposed an on-line pipe length measurement for straight and curved pipes with closed ends using stationary waves which were generated in the pipes. The system adopted several modes of the stationary wave as state variables of a linear dynamic system and reduced the length measurement to a parameter estimation problem, and thereby realized a highly accurate pipe length measurement. This paper presents a new length measurement system for straight pipes with open ends. Experiments will show that a highly accurate pipe length measurement is realized without any trouble on the annoying open end compensation.
