Active vibration isolation control: Comparison of feedback and feedforward control strategies applied to Coriolis mass-flow meters

Abstract

Abstract-In this paper we describe the design, implementation and results of multi degree of freedom (DOF) active vibration control for a Coriolis mass-flow meter (CMFM). Without vibration control, environmental vibrational disturbances results in nanometre movement of the fluid-conveying tube which causes erroneous mass-flow measurements. In order to reduce the transmissibility from external vibrations to the internal tube displacement active vibration control is applied.A comparison of a feedback control strategy (adding virtual mass and skyhook damping) and an adaptive feedforward control strategy is made, taking into account the sensor noise levels. Theoretic results are validated with a multi-DOF experimental setup, showing up to 40dB reduction of the influence of external vibrations. The amount of reduction is limited by the sensor noise levels.

Self-tuning MIMO disturbance feedforward control for active hard-mounted vibration isolators

“…Compared to feedback control, the advantages of feedforward control are two-fold. First, it often leads to better signal-to-noise ratios because the measured disturbance signals are not (mechanically) low-pass filtered by the passive vibration isolator itself [11]. Second, feedforward control does not affect the closed-loop stability properties, whereas highgain feedback control requires a high bandwidth that can lead to stability problems.…”

Coriolis mass-flow meter with integrated multi-DOF active vibration isolation

“…These strategies are compared on the ability to reduce the influence of external vibrations on the mass-flow measurement value. Several advances are made on previous work [6,21,22] : (i) the feed-forward strategy is extended to Multiple-Input-Multiple-Output (MIMO), (ii) the influence of the sensor noise levels is included in the analysis and (iii) the systems performance is validated for 3D disturbances.…”

Vibration isolation for coriolis mass-flow meters

“…These strategies are compared on the ability to reduce the influence of external vibrations on the mass-flow measurement value. Several advances are made on previous work [70,74,59]: (i) the feedforward strat- egy is extended to Multiple-Input-Multiple-Output (MIMO), (ii) the influence of the sensor noise levels is included in the analysis and (iii) the systems performance is validated for 3D disturbances.…”