# US 2008/0189038 A1 · Driving Assistance System for Interaction Between a Mobile Element and an Infrastructure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0189038 A1 - Document ID: US20080189038A1 - Status: Published application - Kind: A1 - Application number: 11/566,047 - Filed: 2006-12-01 - Published: 2008-08-07 - Earliest claimed: 2004-06-02 - Assignees: Centre National de la Recherche Scientifique (CNRS); Universite Pierre & Marie Curie - Inventors: Stephane Hole; Daniele Fournier; Celine Filloy-Corbrion - Web page: https://patentgrep.com/patent/US20080189038A1 ## CPC - G05D 1/0261: {using magnetic plots} - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES ## Abstract The invention concerns a driving aid system file supplying data to a vehicle running on an infrastructure, and comprising a magnetic marking formed on the infrastructure and adapted to encode data addressed to said vehicle, said data being modifiable, and a detection device comprising a plurality of magnetic sensors onboard the vehicle for detecting a total magnetic field including the magnetic field generated by the magnetic marking and for producing signals representing the total magnetic field, and a processing unit adapted to process the representative signals, and to determine a first distance between the vehicle and the magnetic marking, and to decode the data encoded on the magnetic marking ## Claims ### Claim 1 A driving assistance system for supplying information to a vehicle traveling on an infrastructure, the system comprising: a magnetic marking formed on or in the infrastructure and adapted to encode the information intended for said vehicle, said information being modifiable, a detection device comprising a plurality of magnetic sensors placed on board said vehicle to detect a total magnetic field comprising the magnetic field generated by said magnetic marking and to produce signals representing said total magnetic field, and a processing unit adapted to process said representative signals and to determine, on the one hand, a first distance between said vehicle and said magnetic marking, and, on the other hand, to decode the information encoded in said magnetic marking ### Claim 2 (depends on 1) The driving assistance system as claimed in claim 1, in which the magnetic marking is formed by depositing a marking compound intended for road signaling, to which are added one or more magnetic materials in the form of particles, said particles being capable of receiving remanent magnetization when subjected to a magnetic field greater than the coercive magnetic excitation fields of said particles, the remanent magnetization of said particles being adapted to encode the information intended for said vehicle. ### Claim 3 (depends on 2) The driving assistance system as claimed in claim 2, in which there are at least two different varieties of magnetic materials in the magnetic marker, each having a different coercive magnetic excitation field, so that the information intended for the vehicle can be encoded with different safety levels, the most important information being encoded with the magnetic materials having the highest coercive magnetic excitation fields. ### Claim 4 (depends on 1) The driving assistance system as claimed in claim 1, in which the magnetic marker is deposited in a substantially continuous way in the form of a magnetic strip, and in which the information is encoded at substantially regular elementary intervals along the length of said magnetic strip, each of said elementary intervals having its own multidirectional magnetic field. ### Claim 5 (depends on 1) The driving assistance system as claimed in any claim 1, in which the magnetic marker is deposited in the form of a discontinuous magnetic strip formed by substantially regular elementary intervals, and the information is encoded in each regular elementary interval, each of said elementary intervals having its own multidirectional magnetic field. ### Claim 6 (depends on 4) The driving assistance system as claimed in claim 4, in which the elementary interval has a length in the range from once to twice the mean height between the magnetic strip and the on-board magnetic sensors. ### Claim 7 (depends on 4) The driving assistance system as claimed in claim 4 in which the multidirectional magnetic field comprises at least a first component in a direction substantially perpendicular to, but coplanar with, the direction of the magnetic strip. ### Claim 8 (depends on 2) The driving assistance system as claimed in claim 2, in which the particles of magnetic materials are associated with a resin. ### Claim 9 (depends on 2) The driving assistance system as claimed in claim 2, in which the magnetic materials are magnetic ferrites. ### Claim 10 (depends on 2) The driving assistance system as claimed in claim 2, in which the particles of magnetic materials take the form of powders, beads or chips whose diameters range from 10 nm to 2 mm. ### Claim 11 (depends on 2) The driving assistance system as claimed in claim 2, in which the compound intended for road signaling is a paint, preferably water-based. ### Claim 12 (depends on 1) The driving assistance system as claimed in claim 1, in which the plurality of magnetic sensors comprises at least three magnetic sensors, the processing unit also being adapted to eliminate the surrounding magnetic field from the total magnetic field on the basis of the representative signals from the magnetic sensors. ### Claim 13 (depends on 12) The driving assistance system as claimed in the claim 12, comprising at least a fourth magnetic sensor, and in which the processing unit is also adapted to take into account the bias due to the variations of the surrounding magnetic field, particularly those due to the distribution of metallic bodies, on the basis of the representative signals from said magnetic sensors ### Claim 14 (depends on 13) The driving assistance system as claimed in claim 13, in which the magnetic sensors are aligned on a first axis substantially perpendicular to the axis of the vehicle. ### Claim 15 (depends on 14) The driving assistance system as claimed in claim 14, comprising at least one supplementary magnetic sensor positioned on a second axis, separate from the first axis, in such a way that the processing unit determines a second distance between the vehicle and the magnetic strip, the processing unit determining on the basis of the first and the second distance the orientation of the vehicle with respect to its direction of movement on the infrastructure ### Claim 16 (depends on 12) The driving assistance system as claimed in claim 12, additionally comprising devices for calibrating the magnetic sensors, these devices being capable of producing supplementary magnetic fields of specified values, the processing unit also being adapted to verify the operating state and to eliminate the disparities in the responses of said magnetic sensors on the basis of the representative signals of said magnetic sensors. ### Claim 17 (depends on 16) The driving assistance system as claimed in claim 16, in which the calibration systems comprise electromagnets. ### Claim 18 (depends on 12) The driving assistance system as claimed in claim 12, in which the magnetic sensors are magnetoresistive sensors, Hall effect sensors, or current loop sensors. ### Claim 19 (depends on 12) The driving assistance system as claimed in claim 12, in which at least one of the first and second distances, and the information encoded in the magnetic strip, are determined by the processing unit on the basis of an estimation function comprising the comparison, by a least squares criterion, of the values read by each of the magnetic sensors (Mfxi, Mgxi, Mhxi) with the values of a standard response of said sensors (fxi, gxi, hxi) which is a function of the total magnetic field, in each of the positions of said magnetic sensors (xi), the estimated values of the distances and of the information being the values which best fit to said read values. ### Claim 20 (depends on 12) The driving assistance system as claimed in claim 12, in which at least one of the first and second distances (d), and the information (c) encoded in the magnetic strip, are calculated on the basis of the values read by each of the magnetic sensors (Mfxi) and the following values: NB=median value of said read values, N=read value corresponding to the value farthest from said median value, and read on the sensor CN in position xCN, NA=read value corresponding to the value closest to said median, and read on the sensor CA in position xCA, as claimed in the formula: d=(xCN*(NA−NB)+xCA*(N−NB))/(N+NA−2*NB), c=(N+NA−2*NB) ### Claim 21 (depends on 1) A detection device for a driving assistance system as claimed in claim 1, comprising a plurality of magnetic sensors intended to be placed on board a vehicle to detect a total magnetic field comprising the magnetic field generated by a magnetic marking formed on or in an infrastructure, and to produce signals representing said total magnetic field, and a processing unit adapted to process said representative signals and to determine a first distance between said vehicle and said magnetic marker, and in which the plurality of magnetic sensors comprises at least three magnetic sensors, and the processing unit is also adapted to eliminate the surrounding magnetic field from the total magnetic field on the basis of said representative signals. ### Claim 22 (depends on 21) The detection device as claimed in claim 21, comprising at least a fourth magnetic sensor, and in which the processing unit is also adapted to take into account the bias due to the variations of the surrounding magnetic field, particularly those due to the distribution of metallic bodies, on the basis of the representative signals from said magnetic sensors. ### Claim 23 (depends on 22) The detection device as claimed in claim 22, in which the magnetic sensors are aligned on a first axis substantially perpendicular to the axis of the vehicle. ### Claim 24 (depends on 23) The detection device as claimed in claim 23, comprising at least one supplementary magnetic sensor positioned on a second axis, separate from the first axis, in such a way that the processing unit determines a second distance between the vehicle and the magnetic strip, the processing unit determining on the basis of the first and the second distance the orientation of the vehicle with respect to its direction of movement on the infrastructure ### Claim 25 (depends on 21) The detection device as claimed in claim 21, additionally comprising devices for calibrating the magnetic sensors, these devices being capable of producing supplementary magnetic fields of specified values, the processing unit also being adapted to verify the operating state and to eliminate the disparities in the responses of said magnetic sensors on the basis of the representative signals of said magnetic sensors. ### Claim 26 (depends on 25) The detection device as claimed in claim 25, in which the calibration systems comprise electromagnets ### Claim 27 (depends on 21) The detection device as claimed in claim 21, in which the magnetic sensors are magnetoresistive sensors, Hall effect sensors, or current loop sensors. ### Claim 28 (depends on 21) The detection device as claimed in claim 21, in which the processing unit is also adapted to decode the information encoded in the magnetic marking ### Claim 29 (depends on 21) The detection device as claimed in claim 21, in which the first and second distances, and the information encoded in the magnetic strip, are determined by the processing unit by means of an estimation function comprising the comparison, by a least squares criterion, of the values read by each of the magnetic sensors (Mfxi, Mgxi, Mhxi) with the values of a standard response of said sensors (fxi, gxi, hxi) which is a function of the total magnetic field, in each of the positions of said magnetic sensors (xi), the estimated values of the distances and of the information being the values which best fit to said read values. ### Claim 30 (depends on 21) The detection device as claimed in claim 21, in which at least one of the first and second distances (d), and the information (c) encoded in the magnetic strip, are calculated on the basis of the values read by each of the magnetic sensors (Mfxi) and the following values: NB=median value of said read values, N=read value corresponding to the value farthest from said median value, and read on the sensor CN in position xCN, NA=read value corresponding to the value closest to said median, and read on the sensor CA in position xCA, according to the formula: d=(xCN*(NA−NB)+xCA*(N−NB))/N+NA−2*NB), c=(N+NA−2*NB) ### Claim 31 (depends on 21) A vehicle which can travel on an infrastructure comprising a magnetic marking formed on or in said infrastructure and adapted to encode information intended for said vehicle, and fitted with a detection device as claimed in claim 21, said device making it possible to determine at least a first distance between said vehicle and said magnetic marking, and to decode the information encoded in said magnetic marking. ### Claim 32 (depends on 1) An infrastructure for a driving assistance system as claimed in claim 1, comprising a magnetic marking formed on or in said infrastructure, and adapted to encode information intended for a vehicle traveling on said infrastructure, the magnetic marking being formed by the deposition of a marking compound intended for road signaling, to which are added one or more magnetic materials in the form of particles, these particles being capable of receiving remanent magnetization when subjected to a magnetic field greater than the coercive magnetic excitation fields of these particles, the remanent magnetization of said magnetic marking being adapted to encode the information intended for said vehicle. ### Claim 33 (depends on 32) The infrastructure as claimed in claim 32, in which there are at least two different varieties of magnetic materials in the magnetic marker, each having a different coercive magnetic excitation field, so that the information intended for the vehicle can be encoded with different safety levels, the most important information being encoded with the magnetic materials having the highest coercive magnetic excitation fields ### Claim 34 (depends on 32) The infrastructure as claimed in claim 32, in which the magnetic marker is deposited in a substantially continuous way in the form of a magnetic strip, and in which the information is encoded at substantially regular elementary intervals along the length of said magnetic strip, each of said elementary intervals having its own multidirectional magnetic field. ### Claim 35 (depends on 32) The infrastructure as claimed in claim 32, in which the magnetic market is deposited in the form of a discontinuous magnetic strip formed by substantially regular elementary intervals, and the information is encoded in each regular elementary interval, each of said elementary intervals having its own multidirectional magnetic field ### Claim 36 (depends on 32) The infrastructure as claimed in claim 32, in which the multidirectional magnetic field comprises at least a first component in a direction substantially perpendicular to, but coplanar with, the direction of the magnetic strip. ### Claim 37 (depends on 32) The infrastructure as claimed in claim 32, in which the particles of magnetic materials are associated with a resin. ### Claim 38 (depends on 32) The infrastructure as claimed in claim 32, in which the magnetic materials are magnetic ferrites. ### Claim 39 (depends on 32) The infrastructure as claimed in claim 32, in which the particles of magnetic materials take the form of powders, beads or chips whose diameters range from 10 nm to 2 mm. ### Claim 40 (depends on 32) The infrastructure as claimed in claim 32, in which the compound intended for road signaling is a paint, preferably water-based. ### Claim 41 A driving assistance method for a vehicle traveling on an infrastructure, comprising a magnetic marking formed on or in said infrastructure and adapted to encode information intended for said vehicle, said vehicle having a detection device which comprises a plurality of magnetic sensors placed on board said vehicle to detect a total magnetic field comprising the magnetic field generated by the magnetic marking, and to produce signals representing said total magnetic field, and a processing unit for the representative signals, the method comprising the following steps: a) using the plurality of magnetic sensors to measure the total magnetic field, b) using the processing unit to determine the information encoded in the magnetic strip on the basis of said representative signals, c) using the processing unit to determine a first distance between said vehicle and said magnetic marker on the basis of said representative signals, d) transmitting said encoded information and said first distance to a module forming an interface with the driver of the vehicle. ### Claim 42 (depends on 41) The driving assistance method as claimed in claim 41, in which the plurality of magnetic sensors comprises at least three magnetic sensors, the processing unit also being adapted to eliminate the surrounding magnetic field from the total magnetic field on the basis of said representative signals. ### Claim 43 (depends on 42) The driving assistance method as claimed in claim 42 in which the plurality of magnetic sensors comprises at least a fourth magnetic sensor, the processing unit also being adapted to take into account the bias due to the variations of the surrounding magnetic field, particularly those due to the distribution of metallic bodies, on the basis of the representative signals from said magnetic sensors. ### Claim 44 (depends on 43) The driving assistance method as claimed in the preceding claim 43, in which the magnetic sensors are aligned on a first axis substantially perpendicular to the axis of the vehicle. ### Claim 45 (depends on 44) The driving assistance method as claimed in claim 44, comprising at least one supplementary magnetic sensor positioned on a second axis, separate from the first axis, in such a way that the processing unit determines a second distance between the vehicle and the magnetic strip, the processing unit determining on the basis of the first and the second distances the orientation of the vehicle with respect to its direction of movement on the infrastructure. ### Claim 46 (depends on 42) The driving assistance method as claimed in claim 42, in which the magnetic marking is formed by depositing a marking compound intended for road signaling, to which are added one or more magnetic materials in the form of particles, said particles being capable of receiving remanent magnetization when subjected to a magnetic field greater than the coercive magnetic excitation fields of said particles, the remanent magnetization of said magnetic marking being adapted to encode the information intended for said vehicle ### Claim 47 (depends on 46) The driving assistance method as claimed in claim 46, in which there are at least two different varieties of magnetic materials in the magnetic marker, each having a different coercive magnetic excitation field, so that the information intended for the vehicle can be encoded with different safety levels, the most important information being encoded with the magnetic materials having the highest coercive magnetic excitation fields ### Claim 48 (depends on 47) The driving assistance method as claimed in claim 47, in which at least one of the first and second distances, and the information encoded in the magnetic marking, are determined by the processing unit on the basis of an estimation function comprising the comparison, by a least squares criterion, of the values read by each of the magnetic sensors (Mfxi, Mgxi, Mhxi) with the values of a standard response of said sensors (fxi, gxi, hxi) which is a function of the total magnetic field, in each of the positions of said magnetic sensors (xi), the estimated values of the distances and of the information being the values which best fit to said read values. ### Claim 49 (depends on 47) The driving assistance method as claimed in claim 47, in which at least one of the first and second distances (d), and the information (c) encoded in the magnetic strip, are calculated on the basis of the values lead by each of the magnetic sensors (Mfxi) and the following values: NB=median value of said lead values, N=lead value corresponding to the value farthest from said median value, and read on the sensor CN in position xCN, NA=read value corresponding to the value closest to said median, and read on the sensor CA in position xCA, according to the formula: d=(xCN*(NA−NB)+xCA*(N−NB))/(NtNA−2*NB), c=(N+NA−2*NB).