Apparatus and method for determining the linear position of a hydraulic cylinder
Reference Number: N 01-03
Inventors: Allen, William E.; Bitar, Ali A.; Herold, Robert A.
Owner: NISTAC
USPTO Link:5471147
Invention Summary
In one aspect of the present invention, an apparatus for detecting a linear position
of a piston and a piston rod is provided. The piston and piston rod are movable within
a housing and form first and second coaxial resonant cavities. The apparatus includes
RF sections for determining the resonant frequencies of the cavities and a sensor
controller for determining the position of the piston and piston rod.
In another aspect of the invention, a method for detecting a linear position of a
piston and a piston rod is provided. The piston and piston rod are movable within
a housing and define first and second coaxial resonant cavities. The method includes
the steps of determining the resonant frequency of one of the cavities and responsively
determining a first location of the piston. If the first location is invalid then
the resonant frequency of the other cavity is determined and a second location is
responsively determined.