# US 2019/0170852 A1 · Method and system of geolocation by direct calculation of movement elements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170852 A1 - Document ID: US20190170852A1 - Status: Published application - Kind: A1 - Application number: 16/322,806 - Filed: 2017-08-01 - Published: 2019-06-06 - Earliest claimed: 2016-08-02 - Assignees: Thales - Applicants: Thales - Inventors: Alain LEMER; Frédérique YWANNE - Web page: https://patentgrep.com/patent/US20190170852A1 ## CPC - G01S 5/0289: {of multiple transceivers, e.g. in ad hoc networks} - G01S 5/02525: {Gathering the radio frequency fingerprints} - G06F 17/18: for evaluating statistical data {, e.g. average values, frequency distributions, probability functions, regression analysis (forecasting specially adapted for a specific administrative, business or logistic context G06Q10/04)} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method that exploits all of the uncertainties of the ranging measurements and the positions of the anchors is provided, so as to modify the position of the anchors and arrive at a minimal squared error in the ranging measurements. The result of the implementation of the method allows the position of one or more objects in a given space to be obtained precisely. ## Claims ### Claim 1 A method for determining the position of one or more objects able to move in a network, one or more objects being provided with an ability to measure distance to the other objects of the network, at least some of the coordinates of an object are known, wherein it comprises at least the following steps: defining a set of points Ai or anchors and the uncertainties associated with their coordinates, the coordinates of the anchors and the uncertainty as to the coordinates describing information on the position of the objects and the uncertainty as to this information, generating a set containing the estimated positions of the objects and defining an initial position of the points, measuring a set of distances between at least two objects Mi, Mj, with associated uncertainties, and executing the following steps: Step 1, for each object Mi, calculate a displacement δ → → i = ∑ j ∈ R i  δ → j → i corresponding to the vector sum of the ranging or measurement displacements over the set of available ranging measurements toward the object Mi and induced on this object Mi by all of the other objects having a ranging measurement from said object Mi, due to the relative ranging measurement rij between Mi and Mj and its uncertainty σrij, with Ri={rij} all of the available ranging measurements toward Mi, and δ → -> i = ∑ j ∈ R i  δ → j → i   where   δ → j → i = ϕ  ( Δ ij , σ rij )  M j  M i →  M j  M i →  with Δij the coordinates of MjMi, φ is a given displacement function, Step 2, for each object Mi, having an anchoring coordinate in a virtual anchor associated with a fixed anchor Ai, calculate a return displacement value {right arrow over (a)}→i to this anchor, with {right arrow over (a)}→i=Ψ({right arrow over (AiMi)}+{right arrow over (δ)}→i,{right arrow over (σ)}Ai), Ψ a displacement function, Step 3, apply, to each object Mi, a displacement equal to the sum of the ranging displacement {right arrow over (δ)}→i and the anchoring correction {right arrow over (a)}→i that were calculated previously, Step 4, calculate the square of the error term Δtot2 where Δ i 2 = ∑ j ≠ i  Δ ij 2 with Δij=rij−d(Mi,Mj), A is an error term between an estimation of the distance d(Mi, Mj) after displacement of the object in step 3 and the distance measurement provided by ranging devices on all of the nodes, compare this quantity with a stopping criterion defined beforehand by an operator if Δtot2≤Δfin2, or else max(|Δij|) 0  ( anchored   coordinate ) 1 , if   σ = 0  ( fixed   anchored   coordinate ) 0 , if   σ < 0  ( free   coordinate ) where ε represents the deviation from the equilibrium position. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein a displacement function proportional to an intermediate function defined as follows is used: f  ( ɛ , σ ) =  β , where   β   ϵ [ 0 , 1 [ , if   σ > 0  ( anchored    coordinate ) 1 , if   σ = 0  ( fixed   anchored   coordinate ) 0 , if   σ < 0  ( free   coordinate ) . ### Claim 5 (depends on 3) The method as claimed in claim 3, wherein there is taken into account, in a displacement function, a convergence parameter between 0 and 0.5 as a coefficient. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein the coordinates of the anchors Ai are defined as follows: equal to measurements known a priori with a positive or zero uncertainty (this is reflected in the corresponding coordinate of the vector {right arrow over (σ)}Ai), the coordinates are anchoring coordinates, in the absence of measurements, the corresponding coordinate will be unused, and the coordinates are free. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein an initial position of the points {Mi(0)}i=0 . . . N-1 is defined as follows: arbitrarily, deterministically, randomly, by randomly drawing values of the coordinates of the nodes, by using the estimated positions resulting from a previous application of the method, by using the suboptimal resolution method solution, such as pseudo-linearization (PSL), by using anchoring data available for Ai these coordinates are preferably used for the corresponding initial coordinates of Mi. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein an object is designated as master and in that said object is configured to execute the steps of the method as claimed in claim 1, and to centralize the results. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein each object of the network is configured to execute the steps of the method as claimed in claim 1, and to centralize the results. ### Claim 10 (depends on 1) The method as claimed in claim 1, wherein the object whose position is sought is a node in a communication network. ### Claim 11 (depends on 1) A device for determining the position of one or more objects able to move in a network, one or more objects being provided with an inter-node distance measurement device, the nodes communicating with one another by virtue of a communication means, wherein it comprises at least one processor configured to execute the steps of the method as claimed in claim 1, and a device for measuring the position of the nodes.