Ejection speed control system in drop-on-demand applications
Résumé
Piezoelectric micro-pumps are commonly used in drop-on-demand applications for medical purpose and in the printing industry. In such systems, one of the major issue is the control of the ejection speed as well as the detection and the rejection of the perturbations, such as nozzle clogging that modify the ejection speed. In order to diagnose and control such a system, a non-linear model which accounts for the physical behaviour of the drop ejection system is used to derive adaptive control laws, in order to reject perturbations, detects and estimates the nozzle clogging level. Attention is also to given to the case where the speed ejection is not sufficient so that a drop is detached