The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 09, 2010
Filed:
Feb. 20, 2007
Junhua Ding, Tewksbury, MA (US);
Kaveh H. Zarkar, Andover, MA (US);
Junhua Ding, Tewksbury, MA (US);
Kaveh H. Zarkar, Andover, MA (US);
MKS Instruments, Inc., Andover, MA (US);
Abstract
The multiple antisymmetric optimal (MAO) control algorithm is disclosed for a gas delivery system including a flow ratio controller for dividing a single mass flow into multiple flow lines. In the MAO control algorithm, each flow line is provided with a flow sensor and a valve actively controlled by a SISO feedback controller combined with a linear saturator to achieve the targeted flow ratio set point. For optimal control performance, these SISO controller and linear saturators are substantial identical. It is proved that each valve control command is multiple antisymmetric to the summation of all other valve control commands. Therefore, the MAO control algorithm guarantees that there exists at least one valve at the allowable maximum open position at any moment, which achieves the optimal solution in terms of the maximum total valve conductance for a given set of flow ratio set points.