摘要 |
<p>A system and method for controlling a flow of a fluid using a multi-mode control algorithm is described. The method includes disengaging and engaging a feedback control loop that controls a valve of the mass flow controller based upon a rate of pressure change of the fluid. The method also includes calculating a valve position of the valve based on pressure measurements when the feedback control loop has been disengaged and characterization data that characterizes the mass flow controller, and determining, when the feedback control loop is first re-engaged, a difference between a measured flow rate and a flow set point. An adjustment to the characterization data is applied based upon the difference to improve an accuracy of the calculation of the valve position when the feedback control loop is disengaged again.</p> |