Method and device for locating a vehicle
View Patent ↗A method and a device for locating a vehicle, able to estimate a first position of a vehicle from data that are generated by sensors of the vehicle and that are applied to a first particle filter, to store in memory, in a history, for a plurality of times, sensor data that led to the best estimations of a current position t i , to receive at the time t n a corrected GNSS position of the vehicle at a time t 0 , and to estimate using a second particle filter FP 2 a corrected position of the vehicle at a time t i by applying the second particle filter FP 2 to the received corrected GNSS position, to the data stored in memory in association with the time t i and to the dynamic characteristics of the vehicle that are associated with the time t i−1 .
1. A method for locating a vehicle, comprising:
For each time t i of a plurality of successive times [t 0 -t n ]:
Acquiring, from at least one sensor, positioning data and dynamic characteristics of the vehicle,
Estimating the position of the vehicle at a time t i by applying a first particle filter FP 1 to the positioning data acquired at the time t i and to the dynamic characteristics of the vehicle that are associated with a time t i−1 ,
Based on the acquired positioning data, computing a plurality of particles and assigning to each particle having a weight representing a probable position of the vehicle,
Storing in memory, in a history, a subset of the acquired positioning data in association with the time t i of capture of said positioning data, the subset of the acquired positioning data including data that contributed to particles with weight higher than a threshold,
At a time t n :
Obtaining a corrected positioning datum corresponding to the position of the vehicle at a time t 0 , the corrected positioning datum being more precise than the positioning datum acquired from the at least one sensor of the vehicle at the time t 0 ,
Estimating a corrected position of the vehicle at the time t 0 by applying a second particle filter FP 2 to the subset of the acquired positioning data stored in memory in association with the time t 0 and to the obtained corrected positioning datum,
For each history datum stored in memory in an interval [t 1 -t n ]:
Estimating a corrected position of the vehicle at the time t i by applying the second particle filter FP 2 to the subset of the acquired positioning data stored in memory in association with the time t i and to the dynamic characteristics of the vehicle associated with the time t i−1 , and
Predicting a next position of the vehicle based on the estimated corrected position of the vehicle.
2. The method as claimed in claim 1 , wherein the step of obtaining a corrected positioning datum corresponding to the time t 0 comprises:
Obtaining raw positioning data corresponding to the position of a vehicle at the time t 0 from a satellite-positioning receiver,
Transmitting to a processing server positioning data captured at the time t 0 , the server being able to correct the GNSS data,
Receiving from the server corrected positioning data associated with the time t 0 .
3. The method as claimed in claim 1 , wherein the second particle filter FP 2 comprises a number of particles lower than the first particle filter FP 1 .
4. The method as claimed in claim 1 , wherein the subset of the data stored in memory at the time t i that is applied to the second particle filter FP 2 comprises data associated with particles determined by the first particle filter FP 1 for the time t i the weight of importance of which is higher than a threshold.
5. The method as claimed in claim 1 , wherein the second filter FP 2 comprises at least one particle computed by the first filter FP 1 , the particle being such that its weight computed by the filter FP 1 is higher than a threshold.
6. The method as claimed in claim 1 , such that it furthermore comprises transmitting, to a server, a correction datum representative of a discrepancy between the positioning of the vehicle estimated by the at least one sensor at the time t i and the position estimated by the second filter FP 2 for the time t i .
7. A device for locating a vehicle comprising a plurality of sensors, a memory and a processor, the processor being configured by instructions stored in the memory to implement the following steps:
For each time t i of a plurality of successive times [t 0 -t n ]:
Acquiring, from at least one sensor from the plurality of sensors, positioning data and dynamic characteristics of the vehicle,
Estimating the position of the vehicle at a time t i by applying a first particle filter FP 1 to the positioning data acquired at the time t i and to the dynamic characteristics of the vehicle that are associated with a time t i−1 ,
Based on the acquired positioning data, computing a plurality of particles and assigning to each particle having a weight representing a probable position of the vehicle,
Storing in memory, in a history, a subset of the acquired positioning data in association with the time t i of capture of said positioning data, the subset of the acquired positioning data including data that contributed to the particles with weight higher than a threshold,
At a time t n :
Obtaining a corrected positioning datum corresponding to the position of the vehicle at a time t 0 , the corrected positioning datum being more precise than the positioning datum acquired from the at least one sensor of the vehicle at the time t 0 ,
Estimating a corrected position of the vehicle at the time t 0 by applying a second particle filter FP 2 to the subset of the acquired positioning data stored in memory at the time t 0 and to the obtained corrected positioning datum,
For each history datum stored in memory in an interval [t 1 -t n ]:
Estimating a corrected position of the vehicle at the time t i by applying the second particle filter FP 2 to the subset of the acquired positioning data stored in memory at the time t i and to the dynamic characteristics of the vehicle associated with the time t i−1 , and
Predicting a next position of the vehicle based on the estimated corrected position of the vehicle.
8. A vehicle comprising a device for locating the vehicle, the device comprising a plurality of sensors, a memory and a processor, the processor being configured by instructions stored in the memory to implement the following steps:
For each time t i of a plurality of successive times [t 0 -t n ]:
Acquiring, from at least one sensor from the plurality of sensors, positioning data and dynamic characteristics of the vehicle,
Estimating the position of the vehicle at a time t i by applying a first particle filter FP 1 to the positioning data acquired at the time t i and to the dynamic characteristics of the vehicle that are associated with a time t i−1 ,
Based on the acquired positioning data, computing a plurality of particles and assigning to each particle having a weight representing a probable position of the vehicle,
Storing in memory, in a history, a subset of the acquired positioning data in association with the time t i of capture of said positioning data, the subset of the acquired positioning data including data that contributed to the particles with weight higher than a threshold,
At a time t n :
Obtaining a corrected positioning datum corresponding to the position of the vehicle at a time t 0 , the corrected positioning datum being more precise than the positioning datum acquired from the at least one sensor of the vehicle at the time t 0 ,
Estimating a corrected position of the vehicle at the time t 0 by applying a second particle filter FP 2 to the subset of the acquired positioning data stored in memory at the time t 0 and to the obtained corrected positioning datum,
For each history datum stored in memory in an interval [t 1 -t n ]:
Estimating a corrected position of the vehicle at the time t i by applying the second particle filter FP 2 to the subset of the acquired positioning data stored in memory at the time t i and to the dynamic characteristics of the vehicle associated with the time t i−1 , and
Predicting a next position of the vehicle based on the estimated corrected position of the vehicle.