Pitch sensor system
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorFoster L. Striffler
Life of this patent
Estimating the term…
Abstract
A very small pitch sensor which accurately measures angular rotation about he pitch axis while being substantially insensitive to angular rotations about the roll or yaw axes. The pitch sensor comprises a spherical cavity that is fluid filled. The fluid fill further comprises one half conductive fluid and one half dielectric fluid. The fluids are selected to be immiscible and of different densities. The inside of the spherical cavity is segmented into three surface areas for connection to an electronic circuit. The electronic circuit measures voltage differentials between the segmented surface areas which vary with the conductive fluid surface in contact with the respective segmented areas. The conductive fluid surface contact area varies with the angular rotation of the cavity and about the pitch axis.
Claims13
A pitch sensor comprising:
- a housing;
- a spherical cavity contained within said housing, said cavity having a first segment, a second segment, and a third segment, said first and second segments being equal, diametrically opposed, partial hemispheres, said third segment being a ring segment separating said first and second segments, said first, second and third segments having conductive surfaces, said first, second and third segments being electrically isolated from each other, said third segment being electrically grounded;
- a nonconductive dielectric fluid completely filling one half of said spherical cavity;
- a conductive fluid completely filling the remaining half of said spherical cavity, said conductive fluid being immiscible with said nonconductive dielectric fluid, said conductive fluid having a density different from the density of said nonconductive fluid, said conductive fluid providing a first electrical path for electrical current between said first segment and said third segment, said first path having a first conductance proportional to the area of said conductive surface of said first segment in contact with said conductive fluid, said conductive fluid providing a second electrical path for electrical current between said second segment and said third segment, said second path having a second conductance proportional to the area of said conductive surface of said second segment in contact with said conductive fluid, said areas of said conductive surfaces in contact with said conductive fluid being proportional to the inclination of said spherical cavity with reference to a pitch axis, said pitch axis corresponding to the intersection of a first plane and a second plane, said first plane being the plane formed between said conductive and said nonconductive fluids, said second plane being the plane bisecting said third segment into two equal ring portions, said first and second conductances not changing with rotation about a roll axis or a yaw axis, said roll axis and said yaw axis being perpendicular to each other and perpendicular to said pitch axis, said roll axis and said yaw axis further passing through the center of said spherical cavity;
- and
- a sensing means, said sensing means electrically connected to said first, second and third segments, said sensing means having a first input corresponding to said first conductance of said first electrical path, said sensing means having a second input corresponding to said second conductance of said second electrical path, said sensing means having an output signal corresponding to differences in said first and second inputs, said output signal corresponding to the inclination of said spherical cavity about said pitch axis.
Dependencies are inferred from the claim text.