Direction Calculation Using Geomagnetic Map Correction Indoors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing navigation systems using geomagnetism for visually impaired or language-impaired individuals face significant direction inaccuracies due to geomagnetic distortion within buildings, leading to incorrect navigation.
Innovation Solution
A direction calculation apparatus and method that utilizes a geomagnetic map to account for geomagnetic distortion, calculating a corrected direction using a force sensation presentation device by integrating geomagnetic and gravitational vectors, and adjusting the direction based on posture variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If geomagnetism is used for azimuth detection in building navigation, then the navigation system can provide direction guidance to guided persons, but the steel frame and building structures cause significant geomagnetic distortion leading to inaccurate azimuth detection
Solution Approach 1:
The patent introduces an azimuth correction value as an intermediary element that mediates between the distorted geomagnetic azimuth and the true azimuth. This correction value, stored in advance for different locations within the building, acts as a compensating factor that eliminates the harmful effect of geomagnetic distortion without requiring changes to the fundamental geomagnetic detection method
Solution Approach 2:
The patent performs preliminary action by pre-calculating and storing azimuth correction values at various locations within the building before actual navigation occurs. During navigation, the system simply retrieves the appropriate correction value based on the current position, avoiding the need for real-time complex calculations and enabling rapid compensation for geomagnetic distortion
2Ease of operation
If a force sensation presentation device is used to guide directed persons, then intuitive direction presentation is achieved, but the device must accurately calculate direction despite geomagnetic distortion
Solution Approach 1:
The patent implements feedback by continuously monitoring the relationship between the detected azimuth and the true azimuth using stored correction values. The system calculates the difference (azimuth error) and uses this feedback to adjust the direction information presented to the guided person, ensuring that the force sensation guidance remains accurate despite geomagnetic distortion
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
Accurately presents corrected directions to guided individuals, mitigating the effects of geomagnetic distortion and ensuring precise navigation.
Implementation Method 1
uses geomagnetism to detect an azimuth
Implementation Method 2
uses a gravitational acceleration vector which is a vector of gravitational acceleration
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5C
AI summary
Provided is a technique for more accurately calculating a direction to be presented to a guided person using a force sensation presentation device gripped by the guided person, taking into account geomagnetic distortion. A direction calculation apparatus includes a presented direction calculation unit that uses a geomagnetic map including a geomagnetic vector and a gravitational acceleration vector of a reference posture of the force sensation presentation device in a reference coordinate system at a position included in a predetermined range, and uses a first matrix composed of a geomagnetic vector, a gravitational acceleration vector, and an outer product vector of these vectors of the reference posture of the force sensation presentation device in the reference coordinate system at a current position of the force sensation presentation device as well as a second matrix composed of a geomagnetic vector, a gravitational acceleration vector, and an outer product vector of these vectors at a current posture of the force sensation presentation device in the reference coordinate system at the current position of the force sensation presentation device, to calculate, from an instructed force sensation vector in a reference coordinate system indicating a direction to be instructed to the force sensation presentation device, an instructed force sensation vector in a force sensation presentation device coordinate system indicating a direction to be instructed to the force sensation presentation device.