Inertial Sensor Calibration Using GNSS Relative Positioning

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Solution Overview

Problem

Existing calibration apparatuses for inertial sensors, such as acceleration and gyro sensors, are unable to calibrate these sensors while the vehicle is traveling, as they require specific preset locations and orientations.

Innovation Solution

An apparatus and method that utilize a vehicle equipped with multiple GNSS receivers and sensors to calculate relative positions and estimate the attitude and angular velocity of the vehicle, allowing for real-time calibration of inertial sensors regardless of the vehicle's state (traveling or stopped).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If calibration is performed using preset location and orientation methods, then calibration accuracy is improved, but the calibration can only be performed when the vehicle is stationary at specific locations

Engineering Contradiction:

Improvecalibration accuracyVSAvoidcalibration condition flexibility

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transforms the static calibration approach into a dynamic one by enabling calibration during vehicle motion. The system calculates real-time attitude and angular velocity while the vehicle is moving, using multiple GNSS receivers to track position changes and derive rotational information, thus allowing calibration under dynamic conditions rather than requiring static preset locations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent replaces the mechanical requirement of physical positioning at preset locations with a computational system. Instead of requiring the vehicle to be physically placed at specific calibrated locations, the system uses mathematical calculations based on GNSS position data to determine attitude and angular velocity, substituting physical constraints with computational solutions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If calibration requires preset locations and orientations, then measurement precision is improved, but loss of time occurs due to inability to calibrate while traveling

Engineering Contradiction:

Improvesensor calibration accuracyVSAvoidcalibration time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent enables continuous calibration functionality by allowing the calibration process to occur during normal vehicle operation rather than requiring separate stationary calibration sessions. The system continuously processes GNSS data to update attitude and angular velocity estimates, maintaining calibration capability throughout the vehicle's operational lifecycle without interruption to normal use.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The system performs preliminary calculations of relative positions between multiple GNSS receivers to establish the basis for continuous attitude and angular velocity estimation. By pre-processing position data and maintaining ready-to-use computational models, the system can immediately perform calibration during motion without requiring setup time at preset locations.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If multiple GNSS receivers are used to calculate relative position and estimate attitude, then calibration capability during motion is improved, but device complexity increases

Engineering Contradiction:

Improvecalibration condition flexibilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the multiple GNSS receivers serve multiple functions: they simultaneously provide position information for navigation and relative position information for attitude estimation. The same hardware infrastructure supports both conventional navigation operations and the enhanced calibration functionality, avoiding the need for separate dedicated calibration equipment.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system introduces a calibration apparatus as an intermediary that processes data from existing GNSS receivers and inertial sensors. This intermediary component coordinates the complex calculations of relative positions, attitudes, and angular velocities, managing the system complexity by centralizing the computational logic rather than distributing it across multiple independent systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12241910B2Apparatus and method for calibrating inertial sensor

Publication Date: 2025.03.04 DENSO CORP

AI summary

In an apparatus for calibrating an inertial sensor configured to detect an angular velocity of a vehicle, an angular velocity estimator is configured to estimate a value for an angular velocity of the vehicle based on a value for an attitude of the vehicle and a value for a change in attitude of the vehicle estimated by the attitude estimator, and an error estimator is configured to estimate a value for an angular velocity error that is an error between the value for the angular velocity of the vehicle estimated by the angular velocity estimator and the value for the angular velocity of the vehicle detected by the inertial sensor. A calibrator is configured to calibrate the value for the angular velocity of the vehicle detected by the inertial sensor based on the value for the angular velocity error estimated by the error estimator.