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:
Sep. 13, 2005
Filed:
Jan. 30, 2001
Joseph B. Seale, Gorham, ME (US);
Gary E. Bergstrom, Moreland Hills, OH (US);
Joseph B. Seale, Gorham, ME (US);
Gary E. Bergstrom, Moreland Hills, OH (US);
Crystal Investments, Inc., Christ Church, BB;
Abstract
Servo controlled solenoids provide actuation of a pump piston and valves, and electronic LC resonance measurements to determine liquid volume and gas bubble volume. Third order nonlinear servo control is split into nested control loops: a fast nonlinear first-order inner loop causing flux to track a target by varying a voltage output, and a slower almost linear second-order outer loop causing magnetic gap to track a target by controlling the flux target or the inner loop. The inner loop uses efficient switching regulation, preferably based on controlled feedback instabilities, to control voltage output. The outer loop achieves damping and accurate convergence using proportional, time-integral, and time-derivative gain terms. The time-integral feedback may be based on measured and target solenoid drive currents, adjusting the magnetic gap for force balance at the target current.