Geometric Heading Generation Using Declination Database Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods fail to accurately generate geometric heading relative to the geometric north, as they primarily provide magnetic heading based on magnetic north, which varies by position, making it challenging to calibrate geometric heading effectively.
Innovation Solution
A method and system utilizing a declination database to estimate current declination information, combining angular velocity readings from a gyroscope and magnetic heading readings from a magnetometer to generate geometric heading, incorporating a processor and inertial measurement units like gyroscopes and magnetometers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic heading is provided by magnetometer, then magnetic north information is obtained, but geometric north information cannot be directly obtained due to declination variation
Solution Approach 1:
The patent introduces a declination database as an intermediary between the magnetometer and the geometric north reference. The database stores pre-calculated declination values at various geographic positions, allowing the system to retrieve and apply the appropriate declination correction to convert magnetic heading to geometric heading without direct measurement of geometric north
Solution Approach 2:
The declination values are pre-calculated and stored in a database before use. This preliminary action allows the system to quickly retrieve and apply declination corrections during operation, rather than calculating them in real-time, improving the efficiency of the heading conversion process
2Measurement precision
If declination database is used to estimate current declination, then geometric heading can be generated, but system complexity increases
Solution Approach 1:
The processor performs multiple functions: it manages the declination database, estimates current position, retrieves appropriate declination values, and calculates geometric heading. By consolidating these functions in a single processor, the system avoids the need for separate dedicated components for each function, thereby reducing overall system complexity while maintaining geometric heading accuracy
3Reliability
If gyroscope and magnetometer readings are combined, then predicted heading is generated, but integration complexity increases
Solution Approach 1:
The patent combines gyroscope angular velocity readings and magnetometer magnetic heading readings into a single predicted heading calculation. By merging these sensor inputs and processing them together through the same computational pipeline that also applies declination correction, the system achieves reliable geometric heading without requiring separate processing channels, thus limiting the increase in integration complexity
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 enables accurate generation and display of geometric heading relative to the geometric north, enhancing positioning accuracy by accounting for declination differences between magnetic and geometric north.
Implementation Method 1
generating a predicted heading according to an angular velocity reading of a gyroscope
Implementation Method 2
magnetic heading reading of a magnetometer
Data Source
AI summary
A method of generating a geometric heading during positioning is provided. The method includes the following steps: estimating a current declination information of a current position according to a declination database, wherein the declination database gathers a magnetic map and a plurality of declination information corresponding to a difference between a magnetic north and a geometric north at all grid positions on the magnetic map; generating a predicted heading according to an angular velocity reading of a gyroscope and a magnetic heading reading of a magnetometer; and generating the geometric heading according to the current declination information of the current position and the predicted heading.