Optical gyro pick-off

Claim 3

A gyroscope of the type having a gyro rotor with spherical outer surface, platform means for supporting said rotor for rotation about a spin axis and permitting tilting of said rotor about a output axis through an angle plus or minus theta relative to a null position, and means for imparting rotation to said rotor about said spin axis, wherein the imProvement comprises a gyro pickoff system including a pattern of areas disposed between a pair of latitude reference lines relative to said spin axis spaced from each other angularly by twice said latitude reference lines being divided into equal length segments by means of a plurality of equally spaced reference lines of longitude intersecting said spin axis, a plurality of triangle-like areas of alternate orientation of being defined between said lines of latitude by a zig-zag pattern of line segments connected end to end, each line segment interconnecting the intersection of one of said lines of latitude with one line of longitude and the intersection of the other of said lines of latitude with the next adjacent line of longitude, one set of alternate ones of said triangular like areas having different optical properties from the other set of triangle-like areas on the outer spherical surface of said rotor, first receiver means stationary with respect to said platform for receiving radiation reflected from a selected location through which the pattern turns to produce an output signal indicative of the optical properties of said areas passing said location, said pattern having a geometry such that the output of said receiver means is modulated in accordance with the tilt angle of said rotor about a first axis.

Claim 4

A gyroscope of the type having a gyro rotor with spherical outer surface, platform means for supporting said rotor for rotation about a spin axis and permitting tilting of said rotor about a output axis through an angle plus or minus theta relative to a null position, and means for imparting rotation to said rotor about said spin axis, wherein the imProvement comprises a gyro pickoff system including a pattern of areas disposed between a pair of latitude reference lines relative to said spin axis spaced from each other angularly by twice said latitude reference lines being divided into equal length segments by means of a plurality of equally spaced reference lines of longitude intersecting said spin axis, a plurality of triangle-like areas of alternate orientation of being defined between said lines of latitude by a zig-zag pattern of line segments connected end to end, each line segment interconnecting the intersection of one of said lines of latitude with one line of longitude and the intersection of the other of said lines of latitude with the next adjacent line of longitude, one set of alternate ones of said triangular like areas having different optical properties from the other set of triangle-like areas on the outer spherical surface of said rotor, first receiver means stationary with respect to said platform for receiving radiation reflected from a selected location through which the pattern turns to produce an output signal indicative of the optical properties of said areas passing said location, said pattern having a geometry such that the output of said receiver means is modulated in accordance with the tilt angle of said rotor about a first axis.

Claim 5

The system of claim 2, wherein the improvement further comprises second receiver means stationary with respect to said platform for receiving radiation reflected from a location 90* from said selected location observed by said first receiver means to produce an output modulated similarly in accordance with the tilt angle of said rotor about a second axis.

Claim 6

The system of claim 2, wherein said zigzag line segments are great circle arcs.

Claim 7

The system of claim 2, wherein said triangle-like areas are truncated lunes.

Claim 8

The system of claim 2, wherein said one set of areas has different reflectivity from said other set.

Claim 9

The system of claim 2, wherein the improvement further comprises signal processing means including means for averaging the output of said receiver means.

Claim 10

The system of claim 2, wherein the improvement further comprises a second receiver means stationary with respect to said platform for receiving radiation reflected from a location 90* from said selected location observed by said first receiver means to produce an output modualted similarly in accordance with the tilt angle of said rotor about a second axis.

Claim 11

The system of claim 2, wherein said pattern is centered on the equator of said spherical surface relative to said spin axis.

Claim 12

The system of claim 2, wherein the mid-latitude of said pattern is displaced from the equator of said spherical surface relative to said spin axis.

Claim 13

The system of claim 8, wherein the mid-latitude of said pattern is displaced from the equator of said spherical surface relative to said spin axis.

Claim 14

A gyro pick-off system, comprising a free rotor with a spherical outer surface, a platform for supporting said rotor for rotation about a spin axis, means for imparting rotation to said rotor about said spin axis, a pair of perpendicular output axes orthogonal to said spin axis, said rotor being capable of tilting through a maximum angle relative to either output axis, a geometric pattern being provided on said spherical surface of said rotor between a pair of latitude reference lines relative to said spin axis spaced from each other by twice said maximum tilt angle, the mid-latitude between said spaced latitude lines being displaced from the equator of said spherical surface, said latitude reference lines being intersected by a plurality of equally spaced reference lines of longitude bisected by said spin axis, a plurality of truncated lunes of alternate orientation being defined between said latitude reference lines by a zigzag pattern of great circle arcs connected end-to-end, each said arc interconnecting the intersection of one of said liNes of latitude and one line of longitude with the intersection of the other of said lines of latitude and the next adjacent line of longitude, the areas defined on said surface by one set of said alternate truncated lunes having different optical reflectivity than the areas defined by the other set of truncated lunes, a pair of optical receivers affixed to said platform receiving light reflected from respective locations through which said pattern turns, said locations being normally coincident with said mid-latitude and separated by 90* so as to correspond respectively to said two output axes, means operatively connected to said optical receivers for separately averaging the levels of light received by said pair of optical receivers to produce outputs indicative of the tilt angles of said rotor relative to said two output axes.

Claim 15

A gyro pick-off system, comprising a free rotor with a spherical outer surface, a platform for supporting said rotor for rotation about a spin axis, means for imparting rotation to said rotor about said spin axis, a pair of perpendicular output axes orthogonal to said spin axis, said rotor being capable of tilting through a maximum angle relative to either output axis, a geometric pattern being provided on said spherical surface of said rotor between a pair of latitude reference lines relative to said spin axis spaced from each other by twice said maximum tilt angle, the mid-latitude between said spaced latitude lines being displaced from the equator of said spherical surface, said latitude reference lines being intersected by a plurality of equally spaced reference lines of longitude bisected by said spin axis, a plurality of truncated lunes of alternate orientation being defined between said latitude reference lines by a zigzag pattern of great circle arcs connected end-to-end, each said arc interconnecting the intersection of one of said liNes of latitude and one line of longitude with the intersection of the other of said lines of latitude and the next adjacent line of longitude, the areas defined on said surface by one set of said alternate truncated lunes having different optical reflectivity than the areas defined by the other set of truncated lunes, a pair of optical receivers affixed to said platform receiving light reflected from respective locations through which said pattern turns, said locations being normally coincident with said mid-latitude and separated by 90* so as to correspond respectively to said two output axes, means operatively connected to said optical receivers for separately averaging the levels of light received by said pair of optical receivers to produce outputs indicative of the tilt angles of said rotor relative to said two output axes.