Method for locating an object using a reference grid
AssigneeCommissariat a I'energie atomique et aux ene alt
InventorChristophe Villien
Life of this patent
Estimating the term…
Abstract
A method for locating an object by a reference grid, the object moving in a plane parallel to or identical to that of the grid. When crossing of a line of the grid is detected by the object, its heading is determined and, as a function of the detection, probabilities of the thus crossed line being a horizontal line and a vertical line respectively are obtained. Displacement of the object is assessed from the probabilities obtained and a horizontal and vertical pitch of the grid. A position of the object is then updated from a position of the object determined during a last line crossing of the grid and the displacement thus assessed.
Claims16
1-15. (canceled)
A method for locating an object by a reference grid, the object moving in a plane parallel to or identical to that of the grid, the grid being defined by a plurality of horizontal lines, aligned along a first direction, and a plurality of vertical lines, aligned along a second direction distinct from the first direction, the vertical lines being separated by a first distance along the first direction and the horizontal lines being separated by a second distance along the second direction, the method comprising, each time the object crosses a line of the grid:
- determining a heading of the object with respect to a reference direction;
- obtaining, as a function of the heading thus determined, probabilities p(dy1/φ1), p(dx1/φ1) of the line thus crossed being respectively a horizontal line and a vertical line of the grid, when the object moves in the direction given by the course;
- assessing, from the probabilities and the first and second distances, displacement (, ) of the object since a last time the object crossed the line of the grid;
- updating a position of the object from the assessed displacement.
The locating method according to claim 14, wherein, the first direction being selected as the reference direction, the probability p(dx1/φ1) of the crossed line being a vertical line is determined by
- p
-
- (
- d
-
-
- x
- l
- |
- ϕ
- l
- )
- =
- tan
-
- (
- θ
- )
- tan
-
- (
- θ
- )
- +
-
- tan
- (
- ϕ
- 1
- )
-
- and the probability p(dy1/φ1) of the crossed line being a horizontal line is determined by
- p
-
- (
- d
-
-
- y
- l
- |
- ϕ
- l
- )
- =
- tan
-
- (
- ϕ
- 1
- )
- tan
-
- (
- θ
- )
- +
-
- tan
- (
- ϕ
- 1
- )
-
- ,
- where tan(θ)=Ly/Lx, Lx and Ly being respectively the first and second distances and φ1 being the heading.
The locating method according to claim 28, wherein the second sensor is a gyroscope.
Dependencies are inferred from the claim text.