Model-based design of tube pumps with ultra-low flow rate pulsation

In this paper, a model-based design problem of tube pumps are considered to achieve an ultra-low flow rate pulsation. Starting from the modelling of conventional tube pumps having two rollers, we clarify the fact that even the 1 degree of freedom (DoF) structure can realize a flat flow rate by adjusting the rotation speed. Then, it is shown that the 2 DoF setting reduces the amount of the required acceleration of the pushing roller. Equivalently, this can be achieved by a deceleration of the leaving roller. An alternative way to realize it with a constant rotation speed is to modify the wall curve profile at the leaving sector. Its modelling and an optimal design procedure based on this model are given. Finally, we propose a control strategy combining a quasi-optimal wall curve with slight speed adjustment at the bottom of the periodic operation cycle to achieve an almost pulsation-free flow rate.