Vehicle Positioning Using Error State Kalman Filter

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Solution Overview

Problem

Existing vehicle positioning and orientation systems face challenges in achieving precise determination due to limitations in integrating inertial measurement data with odometer and satellite geolocation data, leading to inaccuracies and reduced precision.

Innovation Solution

A method utilizing a closed-loop integration scheme with an Error State Kalman Filter (ESKF) that combines inertial navigation data with odometer and satellite geolocation data, correcting position and orientation estimates by accounting for measurement biases and scale factor variations, and averaging angular speed measurements over intervals to improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If inertial measurement integration module constructs position and orientation from accelerometer and gyrometer measurements, then continuous position and orientation estimation is achieved, but measurement precision deteriorates due to accumulation of errors

Engineering Contradiction:
Improvecontinuous position estimationVSAvoidposition estimation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The correction module uses feedback from multiple sensors (odometer, satellite geolocation unit) to continuously correct the position and orientation estimates generated by the inertial measurement integration module. This feedback loop compensates for error accumulation and maintains measurement precision while preserving continuous estimation capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system merges data from multiple sensor sources (accelerometer, gyrometer, odometer, satellite geolocation unit) through a unified correction module that processes all measurements together. This combination allows the system to leverage the strengths of each sensor while compensating for their individual weaknesses, resolving the contradiction between continuous estimation and precision.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If correction module uses odometer and satellite geolocation measurements to correct position estimates, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improveposition estimation accuracyVSAvoidsensor integration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The correction module is designed with multi-functionality, handling corrections from multiple sensor types (odometer, satellite geolocation unit) through a unified processing architecture. This universal approach allows the system to improve measurement precision using multiple sensors while managing complexity through a single integrated correction mechanism rather than separate processing paths.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If system integrates multiple sensor measurements, then measurement precision improves, but processing time increases

Engineering Contradiction:
Improveposition and orientation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary processing of sensor measurements by pre-calculating correction values and preparing correction data in advance. This preliminary action reduces the computational burden during real-time position estimation, allowing the system to integrate multiple sensor measurements for improved precision without significant increases in processing time.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3967975B1Method for determining the position and orientation of a vehicle
Publication Date: 2024.06.26 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3967975B1 patent drawingFigure 1~2
  • EP3967975B1 patent drawingFigure 3
  • EP3967975B1 patent drawingFigure 4~5

AI summary

This process includes: - for several instants tk between instants toj-1 and toj, the construction (84) of an estimate of the instantaneous value of the physical quantity from the measurements of an inertial navigation unit, then - the construction (106) of an estimate of the physical quantity for the instant toj by calculating the arithmetic mean of these instantaneous values ​​constructed, then - the calculation (108) of a difference between a measurement of this physical quantity obtained from the measurement of an odometer and this estimate of the physical quantity at the instant toj, and - the correction (110), as a function of the difference calculated for the instant toj, of the estimated position and orientation of the vehicle, to obtain a corrected position and a corrected orientation.