Angular Velocity Correction Using Map Data and Oblique Angle Compensation

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Solution Overview

Problem

Existing angular velocity correcting devices for navigation systems face challenges in accurately correcting gyro angular velocity due to sensor mounting pitch angles, vehicle pitch angles, and sensitivity errors, especially in environments where GPS signals are weak or unavailable, leading to position and orientation inaccuracies, particularly in multistory parking garages.

Innovation Solution

The solution involves an angular velocity correcting device and method that calculates and corrects sensor sensitivity by considering both the oblique angle of the sensor with respect to the horizontal plane and the sensitivity error, using a first and second sensitivity correcting method to ensure accurate orientation alignment with GPS data, even in conditions where GPS signals are unreliable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If GPS orientation is used to correct angular velocity sensor sensitivity, then orientation accuracy is improved, but the system fails when GPS signals are unavailable or unreliable

Engineering Contradiction:

Improveorientation accuracyVSAvoidsystem reliability in GPS-denied environments

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent introduces map data as an intermediary reference system. When GPS is unavailable, the system uses pre-stored map data containing road orientation information to correct angular velocity sensor drift, replacing GPS as the reference mediator for sensitivity correction

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary actions by pre-storing map data with road orientation information before GPS signal loss occurs. This allows the system to have correction reference data ready in advance, enabling continuous operation without GPS signals

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If angular velocity sensor is mounted at an oblique angle to detect vehicle orientation, then installation flexibility is improved, but sensitivity error increases due to pitch angle deviation

Engineering Contradiction:

Improveinstallation flexibilityVSAvoidangular velocity sensitivity accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system dynamically changes the sensitivity parameter based on the detected oblique angle. By measuring the actual mounting angle and calculating the corresponding sensitivity correction factor, the system adapts the sensitivity parameter to compensate for the oblique mounting position, maintaining measurement accuracy despite installation flexibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system implements feedback by continuously monitoring the oblique angle of the angular velocity sensor and using this information to adjust the sensitivity correction. The measured angle feeds back into the sensitivity calculation, creating a closed-loop system that maintains accuracy despite mounting variations

Inventive Principle:

Principle #23Feedback

3Device complexity

If sensitivity correction is performed using only GPS data, then correction simplicity is improved, but accuracy deteriorates in multistory parking garages with large pitch angle variations

Engineering Contradiction:

Improvecorrection method simplicityVSAvoidposition and orientation accuracy in parking garages

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The correction system is segmented into multiple independent components: GPS-based correction for open environments, map data-based correction for GPS-denied environments, and oblique angle compensation as a separate correction layer. This segmentation allows the system to select appropriate correction methods based on environmental conditions without increasing overall complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system adds another dimension to the correction approach by incorporating map data with three-dimensional road orientation information. This additional dimensional reference (pre-stored map orientations) complements GPS data and enables accurate correction in environments where GPS alone is insufficient

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS8185308B2Angular velocity correcting device, angular velocity correcting method, and navigation device

Publication Date: 2012.05.22 ALPINE ELECTRONICS INC

AI summary

Angular velocity correcting devices, angular velocity correcting methods, and navigation devices are disclosed. In some implementations, a first sensor sensitivity correcting method for considering variation of sensor sensitivity due to an oblique angle of an angular velocity detecting sensor with respect to a horizontal plane and a sensitivity error of the angular velocity detecting sensor and correcting the sensor sensitivity is enabled. A second sensor sensitivity correcting method for considering the variation of the sensor sensitivity due to the oblique angle of the angular velocity detecting sensor with respect to the horizontal plane without considering the sensitivity error and correcting the sensor sensitivity is enabled. The sensitivity error is calculated on the basis of a ratio of the sensor sensitivity obtained by the first sensor sensitivity correcting method to the sensor sensitivity obtained by the second sensor sensitivity correcting method. The angular velocity from the angular velocity detecting sensor using the sensitivity error is corrected.