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:
Aug. 07, 2001
Filed:
Apr. 30, 1999
Dennis K. Reust, Stillwater, OK (US);
Other;
Abstract
A hydraulic force servo system provides apparatus for compensating for unequal loading forces applied to an actuator piston, and for unequal areas on opposite faces of the piston. Asymmetric nonlinear differential hydraulic force feedback from the output side of a force servovalve is summed with the hydraulic control signal inputs to the output stage of the servovalve at hydraulic summing junctions. Impedances offered by orifices in the feedback lines determine the amount of feedback. Nonlinear characteristics of the feedback method serve to compensate for nonlinearities in the servo actuator and system. The impedance ratio of the orifices is selected as a function of the known or postulated asymmetry of the loading forces to be applied to the actuator piston, and the ratio of the areas of the opposing faces of the actuator piston. Hydraulic damping further improves linearity and stability.