Patent US6574352B1 successfully refreshed from Google Patents.
US6574352B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for anticipation and tracking of eye movement
Assignee: Rockwell Collins Simulation and Training Solutions LLC
•
Filing: 1999-05-18
•
Granted: 2003-06-03
•
Expires: 2019-05-18
Abstract
Abstract A method for anticipation and tracking eye movement for head tracked projectors which divides a projection surface into spherical triangles and uses interpolating calibration values stored at each vertex of the triangle. A calibration map is used that contains information about the relationship between the user's head orientation and where they are looking with their eyes at each calibration point. The projection surface is divided into spherical triangles which are searched to find the triangle which contain the user's interpolated view point by performing a dot product test between the interpolated view point and the unit normal vectors inside the three planes that make up the sides of the spherical triangle extended back to the eye point. When a dot product test fails for any side of the triangle the pointer is followed to the adjacent triangle where the test starts over. When the triangle is found that has the interpolated view point inside it, the selected triangle is divided into three sub-triangles. Then the area of the sub-triangles inside the selected triangle is computed. The areas of the sub-triangles are then used to find ratios of the sub-triangles' areas versus the selected spherical triangle area for weighting the calibration points stored with each vertex. Then the weighted calibrations are added to the values for the interpolated view point. This creates a calibrated view point where the head tracked projector is then pointed and the computer generated simulated image is projected.
Inventors
- 👤 Philip Skolmoski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:10
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/30; G09B9/307
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
212 words
A method for anticipation and tracking of a user's eye movements in a head tracked image generation system, comprising the steps of: (a) defining a viewing surface segmented into a plurality of contiguous triangles across the viewing surface upon which a head tracked image generator displays computer generated images, wherein the contiguous triangles are selected from the group consisting of planar triangles, spherical triangles and contoured triangles; (b) identifying a plurality of calibration values for vertices of the triangles; (c) developing a value from the calibration values representing a difference between (i) a user's head orientation and (ii) where a user is actually looking; (d) interpolating a user's view point onto the viewing surface to determine an interpolated view point where the images should be displayed on the viewing surface; (e) searching the plurality of triangles to find a selected triangle which contains the interpolated view point; (f) dividing the selected triangle containing the view point into three contiguous sub-triangles with common edges extending from three vertices of the selected triangle to a common vertex point corresponding to the view point; (g) comparing surface areas of the sub-triangles with the selected triangle; and (h) correlating comparative surface areas with the calibration values to identify a proper position for the computer generated images.
Claim 2
Independent Claim
212 words
A method for anticipation and tracking of a user's eye movements in a head tracked image generation system, comprising the steps of: (a) defining a viewing surface segmented into a plurality of contiguous triangles across the viewing surface upon which a head tracked image generator displays computer generated images, wherein the contiguous triangles are selected from the group consisting of planar triangles, spherical triangles and contoured triangles; (b) identifying a plurality of calibration values for vertices of the triangles; (c) developing a value from the calibration values representing a difference between (i) a user's head orientation and (ii) where a user is actually looking; (d) interpolating a user's view point onto the viewing surface to determine an interpolated view point where the images should be displayed on the viewing surface; (e) searching the plurality of triangles to find a selected triangle which contains the interpolated view point; (f) dividing the selected triangle containing the view point into three contiguous sub-triangles with common edges extending from three vertices of the selected triangle to a common vertex point corresponding to the view point; (g) comparing surface areas of the sub-triangles with the selected triangle; and (h) correlating comparative surface areas with the calibration values to identify a proper position for the computer generated images.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein the step of comparing surface areas of the sub-triangles with the selected triangle further comprises calculating surface area ratios of the three sub-triangles in relation to the surface area of the selected triangle.
Claim 4
Dependent Claim
86 words
The method of claim 2 wherein the step of correlating comparative surface areas with the calibration values further comprises the steps of: multiplying the surface area ratios of the sub-triangles with the calibration values at each vertex opposite the sub-triangles in the selected triangle to create weighted calibration values; and adding the weighted calibration values to the interpolated view point to allow the head tracked projector to use a calibrated interpolation point to ascertain where the computer generated images should be displayed on the projection surface.
Claim 5
Dependent Claim
179 words
The method of claim 3 wherein the step of multiplying the surface area ratios of the sub-triangles with the calibration values at each vertex of the original triangle to create weighted calibration values further comprises the step of executing the equation: V=αV A +βV B +γV C wherein V represents the weighted calibration values in the x, y and z-coordinate axes to be added to the interpolated view point, α represents the ratio of the first sub-triangle area to the selected triangle area, β represents the ratio of the second sub-triangle area to the selected triangle area, γ represents the ratio of the third sub-triangle area to the selected triangle area, V A represents the calibration values for a first vertex A of the selected triangle wherein sub-triangle α is opposite V A, V B represents the calibration values for a second vertex B of the selected triangle where in sub-triangle β is opposite V B, V C represents the calibration values for a third vertex C of the selected triangle, wherein sub-triangle γ is opposite V C .
Claim 6
Dependent Claim
86 words
The method of claim 1 wherein the step of searching the plurality of triangles to find a selected triangle which contains the interpolated view point, further comprises the steps of: selecting a current triangle as a starting point for a search; testing to see if the interpolated view point is within the current triangle; moving to a next adjacent triangle when the interpolated view point is not within the current triangle; and selecting the current triangle when the interpolated view point is within the current triangle.
Claim 7
Dependent Claim
138 words
The method of claim 5 wherein the step of testing to see if the interpolated viewing point is within the current triangle further comprises the steps of: forming three planes which extend between a user's nominal eye point and each pair of vertices in the current triangle, wherein each plane has a unit normal vector and the planes form a pyramid shaped closed volume having the nominal eye point as the apex; performing a dot product test between the interpolated view point and the unit normal of each plane to create a signed scalar value; and comparing a sign of the scalar value with a sign of the unit normal vector such that when the interpolated view point is within the triangle, the sign associated with each unit normal vector will match the sign of the interpolated point.
Claim 8
Dependent Claim
45 words
The method of claim 5 wherein the step of selecting a current triangle as a starting point for a search further comprises selecting a triangle as a starting point for a search which contained the interpolated view point in a previous computer generated image frame.
Claim 9
Dependent Claim
38 words
The method of claim 1 wherein the step of comparing surface areas of the sub-triangles with the selected triangle further comprises of the step of finding the surface areas of the selected triangle and each of its sub-triangles.
Claim 10
Dependent Claim
89 words
The method of claim 8 wherein the step of finding the surface areas of the selected triangle and each of its sub-triangles further comprises the steps of: calculating an angle between each pair of vertices in the selected triangle; forming three cords between each of the selected triangles vertices and the interpolated view point; finding the approximate length of a cord between each pair of vertices; finding the angles for each of the three vertices; computing the area of the selected triangle; and computing the areas of the sub-triangles.
Claim 11
Dependent Claim
80 words
The method of claim 8 wherein the step of finding the surface areas of the selected triangle and each of its sub-triangles further comprises the step of executing the equation: K= (angle A+ angle B+ angle C−ø ) wherein K represents the area of a triangle, angleA represents the angle of a first vertex in a triangle, angleB represents the angle of a second vertex in a triangle, and angleC represents the angle of a third vertex in a triangle.
Claim 12
Dependent Claim
48 words
The method of claim 1 wherein the step of comparing surface areas of the sub-triangles with the selected triangle further comprises finding the surface area ratios of the sub-triangles by taking the area of each of the three sub-triangles and dividing by the area of the selected triangle.
Claim 13
Dependent Claim
22 words
The method of claim 1 wherein the triangles provided with the projection surface are less the ⅛ of the projection surface size.
Claim 14
Dependent Claim
31 words
The method of claim 1 wherein step of providing a plurality of triangles further comprises providing a plurality of triangles wherein each triangle is adjacent to at least one other triangle.
Claim 15
Dependent Claim
44 words
The method of claim 1 wherein the step of providing a plurality of triangles further comprises the step of providing a plurality of triangles which are bounded by a plane and each triangle is bounded by at least one other triangle and 2 planes.
Claim 16
Dependent Claim
44 words
The method of claim 1 wherein the step of providing a plurality of triangles further comprises the step of providing a plurality of triangles which are bounded by a plane and each triangle is bounded by at least two other triangles and 1 plane.
Claim 17
Dependent Claim
16 words
The method of claim 1 wherein the triangle vertices are represented in the Cartesian coordinate system.
Claim 18
Dependent Claim
25 words
The method of claim 1 wherein the representation of the triangles in the Cartesian coordinate system have an origin set at the nominal eye point.
Claim 19
Dependent Claim
20 words
The method of claim 1 wherein the vertices of the triangles are represented in the azimuth and elevation coordinate system.
References Cited (Backward Citations)
EP0155858A1
Cited
US4634384A
Cited
GB2179147A
Cited
WO1987001571A1
Cited
US5266930A
Cited
US6222937B1
Cited
US5841443A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-06-02 | 2006-12-02 | 2007-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-06-02 | 2010-12-02 | 2011-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-06-02 | 2014-12-02 | 2015-06-03 | $7700.00 | Window Closed / Lapsed |