Inertial Navigation Trajectory Correction via Turn Speed Estimation

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Solution Overview

Problem

Conventional inertial navigation systems, such as strapdown Inertial Navigation Systems (SINS) and Dead Reckoning (DR), suffer from significant performance degradation due to sensor drift and bias, especially in indoor environments where Global Navigation Satellite Systems (GNSS) signals are unavailable, leading to inaccurate positioning solutions.

Innovation Solution

A method and system that utilize motion sensor data from devices with at least one accelerometer to detect correction events, such as turns, estimate the speed of turn, and correct the navigation trajectory, enhancing positioning accuracy without relying on external navigation sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional inertial navigation systems (SINS/DR) are used for positioning, then the system can operate independently without external navigation sources, but the positioning accuracy degrades significantly due to sensor drift and bias accumulation

Engineering Contradiction:
Improveindependent operation capabilityVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system detects correction events (turns, stops, starts) and uses them to generate correction signals that compensate for sensor drift and bias accumulation. The feedback mechanism continuously monitors navigation solution quality and applies corrections at identified correction events, resolving the contradiction by maintaining independent operation while preventing accuracy degradation through periodic correction.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system pre-identifies correction events based on motion patterns before accuracy degradation becomes severe. By detecting turns, stops, and starts in advance and preparing correction signals at these predetermined moments, the system proactively prevents drift accumulation rather than reacting after accuracy is lost, maintaining both independence and precision.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If traditional correction methods using external navigation sources (GNSS, maps) are employed, then positioning accuracy can be maintained, but computational demands and power consumption increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system uses the device's own motion sensors and detected correction events to generate correction signals without requiring external navigation sources. By self-servicing the navigation solution through internally-generated correction signals based on detected turns, stops, and starts, the system maintains positioning accuracy while minimizing power consumption and computational demands.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system replaces expensive, power-intensive external navigation sources (GNSS receivers, detailed map databases, complex processing algorithms) with simple, low-cost correction events detection and basic correction signal generation. This substitution maintains adequate positioning accuracy for the application while dramatically reducing computational resources and power requirements.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If complex correction algorithms are used to maintain accuracy, then positioning precision improves, but device complexity and processing requirements increase

Engineering Contradiction:
Improvenavigation solution accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The correction process is segmented into distinct correction events (turns, stops, starts) rather than attempting continuous correction. Each correction event is handled independently with simple detection and correction signal generation, avoiding the need for complex continuous algorithms. This segmentation maintains accuracy while reducing processing complexity to manageable levels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the operational parameters of the correction process by working only at discrete correction events rather than continuously. By transitioning from continuous complex correction to event-based simple correction, the system achieves comparable accuracy with significantly reduced computational complexity and processing requirements.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach improves navigation solution accuracy and reliability by correcting for sensor drift and bias, reducing computational demands and power consumption, making it suitable for cost-effective and efficient implementation in various environments.

Implementation Method 1

estimating speed of turn during the turn of the platform based on measurements from the accelerometer

Methodology Applied
Scientific EffectAccelerometer measurement: Accelerometer

Data Source

PatentUS11592295B2System and method for position correction
Publication Date: 2023.02.28 INVENSENSE INC
  • US11592295B2 patent drawing
  • US11592295B2 patent drawing
  • US11592295B2 patent drawing

AI summary

Devices and methods for providing an enhanced navigation solution are disclosed that involve detecting correction events along a trajectory of a device. Platform speed is estimated based on characteristics of the correction events, such as by estimating speed of turn during the turn of the platform so that a navigation solution is enhanced by correcting the trajectory of the platform using the estimated speed.