Vibrating conduit parameter sensors, operating methods and computer program productors utilizing real normal modal decomposition

Abstract

A plurality of motion signals is received representing motion at a plurality of locations of a vibrating conduit containing material. The received plurality of motion signals is processed to resolve the motion into a plurality of real normal modal components. A process parameter is estimated from a real normal modal component of the plurality of real normal modal components. According to one aspect, the motion signals may be processed by applying a mode pass filter to produce an output that preferentially represents a component of the motion associated with a real normal mode of the vibrating conduit. A process parameter may be estimated from the filtered output using, for example, conventional phase difference techniques. According to another aspect, real normal modal motion is estimated from the received plurality of motion signals, and a process parameter is estimated from the estimated real normal modal motion. For example, motion may be estimated in respective first and second real normal modes, the second real normal mode being preferentially correlated with a Coriolis force. A process parameter may be estimated by normalizing the estimated motion in the second real normal mode with respect to the estimated motion in the first real normal mode to produce a normalized estimate of motion in the second real normal mode, and by estimating a process parameter from the normalized estimate of motion in the second real normal mode.