2002 Volume 15 Issue 9 Pages 469-476
The authors previously developed a length measurement system for straight pipes using Kalman filters and maximum likelihood method. In the system, the stationary waves in pipes were represented by state variables of a linear dynamic system, and on-line accurate length measurement of straight and curved pipes was achieved. In many situations, however, there are necessities of length measurement not only for straight and curved pipes but also for branch pipes.
The paper proposes a measurement system of pipe length and branch point for branch pipes. A criterion for optimal modes of the stationary wave is also presented, and experiments show that an accurate measurement is realized with the method.