Adaptive Kalman Filter Gain for GNSS Dead Reckoning

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Solution Overview

Problem

Integrated Global Navigation Satellite System (GNSS)/dead reckoning (DR) navigation systems face challenges in determining optimal Kalman filter gains due to variations in road conditions and GPS signal environments, leading to position errors in various environments.

Innovation Solution

The system identifies the vehicle's environment using parameters such as speed, number of tracked satellites, and Dilution of Precision (DOP) to adjust the Kalman filter gain, optimizing the weight given to GNSS and DR navigation, thereby improving position estimation accuracy across different environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fixed Kalman filter gain is used in GNSS/DR navigation, then the system structure is simple, but position estimation accuracy deteriorates in varying environmental conditions

Engineering Contradiction:
Improveposition estimation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a dynamic Kalman filter gain adjustment mechanism that adapts to changing environmental conditions. The system monitors GPS signal quality metrics (such as signal-to-noise ratio, number of visible satellites, and geometric dilution of precision) and dynamically adjusts the Kalman filter gain parameter accordingly. This transforms the static navigation system into a dynamic one that automatically optimizes its performance based on real-time environmental assessments, resolving the contradiction between fixed simplicity and adaptive accuracy.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the Kalman filter gain parameter based on detected environmental conditions. By monitoring GPS signal quality parameters and adjusting the gain parameter dynamically, the system optimizes position estimation accuracy for different environments (urban canyons, open sky, tunnels). This parameter adaptation strategy directly addresses the contradiction by allowing the system to maintain simplicity in structure while achieving high accuracy through intelligent parameter modulation.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If environmental adaptation is added to the Kalman filter, then position estimation accuracy improves, but computational complexity increases

Engineering Contradiction:
Improveposition estimation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies local quality by focusing computational resources on specific environmental assessments rather than进行全面 analysis. The system evaluates key environmental parameters (signal-to-noise ratio, satellite visibility, geometric distribution) and adjusts the Kalman filter gain locally based on these targeted measurements. This selective approach to environmental monitoring reduces overall computational complexity while maintaining the ability to improve position estimation accuracy through adaptive filtering.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS9366764B2Vehicular GPS/DR navigation with environmental-adaptive kalman filter gain
Publication Date: 2016.06.14 GENERAL MOTORS LLC
  • US9366764B2 patent drawing
  • US9366764B2 patent drawing
  • US9366764B2 patent drawing

AI summary

A method is provided for estimating position using an integrated Global Navigation Satellite System (GNSS)/dead reckoning (DR) (GNSS/DR) navigation system in a vehicle. The method includes: determining a current environment of the vehicle from a plurality of environments based on at least one parameter; calculating a Kalman filter-related parameter based on the determined current environment, wherein the Kalman filter-related parameter corresponds to a representation of weight given to GNSS navigation and DR navigation relative to one another; and estimating a position of the vehicle based on the calculated Kalman filter-related parameter utilizing a Kalman filter.