Locating a device that is moved in a three-dimensional space

An apparatus comprising an electronic unit for locating a device displaceable inside a three-dimensional space, the electronic unit comprising:

• a memory containing a map of the three-dimensional space and predefined constraints on the displacements of the device in the three-dimensional space and a computer programmed for:
• executing a first step, repeating a sequence of steps comprising a second step, a third step, and a fourth step, and executing a fifth step,
• wherein the first step comprises generating several distinct particles, each particle being associated:
• with coordinates coding its position on the map and with a weight representing the probability that the device is situated at the site of the particle,
• wherein the second step comprises receiving measurements representative of the direction of displacement of the device and of the amplitude of the displacement from a previous position of the device, the measurements being carried out by sensors onboard the displaced device,
• wherein the third step comprises updating the coordinates of the position of each particle as a function of the measurements received and of a predetermined displacement law for displacing the particle from a previous position thereof to a new position thereof in a manner correlated with the measured displacement of the device,
• wherein the fourth step comprises, for each particle, when the latest displacement of the particle from the previous position to the new position satisfies the predefined constraints, increasing the weight associated with the particle with respect to the weights of the particles whose latest displacement fail to satisfy the predefined constraints, and
• wherein the fifth step comprises estimating the position of the device on the basis of the positions of the particles and of the weights associated with the particles by allotting, during the estimation, more importance to the positions of the particles associated with the highest weights, wherein:
• the map recorded in the memory contains several distinct zones, each distinct zone being associated:
• with coordinates defining the position, on the map, of a periphery thereof, and a predetermined displacement law from among a set of several different displacement laws, wherein at least two of the several distinct zones are associated with different predetermined displacement laws, the predetermined displacement law associated with a zone having been selected because the predetermined displacement law makes it possible to estimate more precisely, on the basis of the same measurements received, the direction and the amplitude of the displacement of the device when the device is situated inside the zone than any one of the other displacement laws of the set of several different displacement laws wherein the different displacement laws are distinguished from one another by mathematical operations that link the coordinates of a particle to the measurements received during the second step, and wherein the computer is further programmed so as to, during the third step and systematically for each particle:
• identify the zone inside which the particle is situated by comparing the coordinates of the particle with the peripheries of the zones of the map, and then use, for the updating of the coordinates of the particle, just the displacement law associated with the identified zone.

A non-abstract method that comprises making an improvement in the way that computers operate and making an improvement in a technical field, wherein the technical field is that of locating a device that is displaced inside a three-dimensional space, wherein said non-abstract method comprises locating the device, wherein locating the device comprises executing a first step, executing a second step, repeatedly executing a third step, a fourth step, and a fifth step, and executing a sixth step, wherein said first step comprises providing a map of the three-dimensional space and of predefined constraints on the displacements of the device in the three-dimensional space, wherein the second step comprises causing an electronic computer to generate several distinct particles, wherein each particle is associated with coordinates that code the position of the particle on the map and with a weight that represents the probability that the device is situated at the site of the particle, wherein the third step comprises receiving measurements representative of the direction of displacement of the device and of the amplitude of the displacement from a previous position of the device, the measurements being carried out by sensors onboard the displaced device, wherein the fourth step comprises updating the coordinates of the position of each particle as a function of the measurements received during the third step and of a predetermined displacement law for displacing the particle from its previous position Pik-1 to a new position Pik in a manner correlated with the measured displacement of the device, wherein the fifth step comprises for each particle, when the latest displacement of the particle from the position Pik-1 to the position Pik satisfies the predefined constraints, increasing the weight associated with the particle with respect to the weights of the particles whose latest displacement fails to satisfy the predefined constraints, wherein the sixth step comprises estimating the position of the device on the basis of the positions of the particles and of the weights associated with the particles by allotting, during the estimation, more importance to the positions of the particles associated with the highest weights, wherein the map that was provided during step the first step contains at least one zone with a favored direction of displacement associated with coordinates defining the position, on the map, of the zone's periphery, and with a favored direction of displacement in the zone, wherein the fifth step further comprises, for each particle:

• detecting the presence of the particle inside the zone with the favored direction of displacement by comparing the coordinates of the particle with the periphery of the zone with the favored direction of displacement defined by the coordinates provided during the first step, and, when the particle is detected as being present inside the zone with the favored direction of displacement, increasing the weight of the particle when the angular deviation between the direction of displacement of the particle from the position Pik-1 to the position Pik and the favored direction of displacement associated with the zone is equal to 0° or to 1800 to within plus or minus σY, wherein increasing the weight is carried out with respect to the weights of the other particles situated inside the same zone and for which the deviation is not equal to 0° or to 180 to within plus or minus σY, where σY is a predetermined angular tolerance, and when the particle is detected as being outside of the zone with the favored direction of displacement, prohibiting the use of the favored direction of displacement associated with the zone to update the weight of the particle.

An apparatus comprising an electronic unit for locating a device that is displaceable inside a three-dimensional space, the electronic unit comprising a memory containing a map of the three-dimensional space and predefined constraints on the displacements of the device in the three-dimensional space and an electronic computer whose functionality has been improved by programming said electronic computer to carry out a function that could not have been carried out in the absence of said programming, wherein said electronic computer has been programmed for executing a first step, repeatedly executing second, third, and fourth steps, and executing a fifth step, wherein the first step comprises generating several distinct particles, each particle being associated with coordinates coding its position on the map, and with a weight representing the probability that the device is situated at the site of the particle, wherein the second step comprises receiving measurements representative of the direction of displacement of the device and of the amplitude of the displacement from its previous position, the measurements being carried out by sensors onboard the displaced device, wherein the third step comprises updating the coordinates of the position of each particle as a function of the measurements received and of a predetermined displacement law for displacing the particle from its previous position Pik-1 to a new position Pik in a manner correlated with the measured displacement of the device, wherein the fourth step comprises, for each particle, when the latest displacement of the particle from the position Pik-1 to the position Pik satisfies the predefined constraints, increasing the weight associated with the particle with respect to the weights of the particles whose latest displacement infringes these predefined constraints, and wherein the fifth step comprises estimating the position of the device on the basis of the positions of the particles and of the weights associated with the particles by allotting, during the estimation, more importance to the positions of the particles associated with the highest weights, wherein the map recorded in the memory contains at least one zone with a favored direction of displacement associated with coordinates defining the position on the map of its periphery, and with a favored direction of displacement in the zone, and wherein, as part of causing an improvement in computer technology caused by having programmed said computer to be able to carry out a novel function, the computer is programmed so as to, during the fourth step, and for each particle:

• detect the presence of the particle inside the zone with favored direction of displacement by comparing the coordinates of the particle with the periphery of the zone with favored direction of displacement defined by the coordinates provided as part of the map of the three-dimensional space and of the predefined constraints on the displacements of the device in the three-dimensional space, and then, when the particle is detected as being present inside the zone with favored direction of displacement, increase the weight of the particle when the angular deviation between the direction of displacement of the particle from the position Pik-1 to the position Pik and the favored direction of displacement associated with the zone is equal to 0° or to 1800 to within plus or minus σY, wherein increasing the weight is carried out with respect to the weights of the other particles situated inside the same zone and for which the deviation is not equal to 0° or to 180 to within plus or minus σY, where σY is a predetermined angular tolerance, and when the particle is detected as being outside of the zone with favored direction of displacement, prohibiting the use of the favored direction of displacement associated with the zone to update the weight of the particle.