Coriolis Mass Flowmeter System
Coriolis mass flowmeters (CMF) are very accurate and reliable mechatronics instruments. The core of the system makes the pipe system consisting of a single pipe or two pipes in parallel through which different fluids flows. The pipes are driven in the fundamental natural frequency of the pipe assembly by the actuator and relative displacements are measured by the sensors. The pipes are often curved.
The detailed modelling of CMF and its Digital Signal Processing (DSP) unit was made using BondSim (see the figure on the left). The model is rather a complex consisting of several hierarchical levels of the components.
The model of the Coriolis transducer consisting of two parallel pipes, actuator and the sensors is shown on the right. The sensors are modelled by simple functions. The actuator on the other hand is modelled as an electro-mechanical component. The digital processing unit is modeled using discrete-time components. The model closely follows the strucure of the real system.
The simulation was run for 30 s. The change of the mean amplitudes and phase of tube vibrations with time are shown in the diagrams below on the left. The next dagram shows the result of the search for the frequency of the operating mode.
