Adaptive Ink Droplet Position Compensation in Three Dimensional Printing

The parabolic droplet trajectory in inkjet printing causes an error between actual and expected position, deteriorating printing quality in high speed printing and reducing strength of printed parts in three dimensional printing. To improve the quality of printing prototype and increase printing speed, an accurate firing time estimation method is proposed to compensate the droplet position error. Firstly, an extended state observer is designed to estimate the carriage's velocity on line. Secondly, the exact firing time for droplet position compensation is calculated based on the estimated carriage velocity and specific droplet jetting speed. Finally, experiments are finished to show the effectiveness and feasibility of this approach.