Design and testing of a feedback position control system using extremely low pressure air

This thesis involved the development of a low pressure pneumatic feedback position control system for reducing the gap between the printing head of an Inkjet printer and the paper. Because of variation of paper thickness (i.e. envelopes) and deformations of structural members the print head is positioned further from the paper than desired (approximately 0.8 mm). Evaluation of this feedback position control system was accomplished in two ways: a computer analytical model was developed, and the airflow equations were solved numerically: and a prototype model of the control system was designed, constructed and tested. The results of the computer simulation showed the feedback position control system to significantly reduce the gap between the printing head and the paper. Steady-state analysis also revealed the best combination of the geometrical parameters of the prototype model. The measurements conducted on the prototype model led to the conclusion that the computer adequately described the feedback position control system. Suggestions and recommendations were given for improvements in the existing design.