Indoor Positioning via PDR and LiDAR Error Correction
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Solution Overview
Problem
Existing location determination methods, such as GPS, are ineffective indoors due to the lack of line of sight, and inertial measurement unit (IMU) based pedestrian dead reckoning (PDR) suffers from velocity drift and inaccuracies, making it challenging to accurately map and track individuals within buildings, especially in public safety applications where precise location and route information are crucial.
Innovation Solution
A system combining a wireless base station, mobile devices with PDR and LiDAR circuits, and a server that corrects PDR errors using ranging mapping data to generate accurate location coordinates and floor plans, integrating PDR positions, LiDAR data, and initial geolocation values to provide precise indoor location tracking and mapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS receiver is used for location determination, then outdoor positioning accuracy is improved, but indoor positioning fails due to lack of line of sight to satellites
Solution Approach 1:
The system divides positioning into two segments: outdoor GPS-based positioning and indoor PDR-based positioning. The mobile device automatically switches between these segments based on location, maintaining continuous positioning capability across different environments.
Solution Approach 2:
The mobile device is equipped with multiple positioning functions (GPS receiver and PDR system) that can operate in different environments. The system universally handles both outdoor and indoor positioning needs through a unified application interface.
2Adaptability or versatility
If PDR is used for indoor location determination, then indoor positioning capability is improved, but positioning accuracy deteriorates over time due to velocity drift and integration errors
Solution Approach 1:
The system continuously monitors positioning accuracy and uses feedback mechanisms to detect drift. When drift exceeds thresholds, the system triggers corrections using landmark recognition, Wi-Fi triangulation, or other reference systems to reset the PDR accumulation errors.
Solution Approach 2:
The system introduces intermediary reference systems (landmarks, Wi-Fi access points, Bluetooth beacons) that act as mediators to periodically correct PDR drift. These intermediaries provide absolute position references that reset the accumulated errors in the inertial navigation system.
3Measurement precision
If detailed LiDAR point cloud data is transmitted for mapping, then mapping accuracy is improved, but data transmission bandwidth requirements increase
Solution Approach 1:
The system extracts only the essential features from complete LiDAR point clouds for transmission. Instead of sending all raw points, it extracts key geometric features, boundary definitions, and landmark characteristics that are sufficient for accurate mapping and positioning.
Solution Approach 2:
The system transmits partial LiDAR data (selected points, features, and boundaries) rather than complete point clouds. This partial action provides sufficient mapping accuracy while dramatically reducing data transmission requirements.
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
The system enables accurate location determination and route mapping within buildings by correcting PDR errors with LiDAR data, providing reliable indoor tracking and enhancing situational awareness, even in environments with bandwidth limitations, by converting LiDAR point clouds into vector graphics for efficient data transmission.
Implementation Method 1
a ranging circuit (21) in the at least one mobile device and configured to generate ranging mapping data of the interior of the building
Implementation Method 2
In some embodiments, the ranging circuit may comprise a Light Detection and Ranging (LiDAR) circuit
Implementation Method 3
a PDR circuit (20) in the at least one mobile device and configured to generate a plurality of PDR positions as a user moves within the interior of the building
Implementation Method 4
The velocity may be integrated over the time period to determine the displacement. In other words, a double integration is performed on the acceleration to arrive at the displacement
Implementation Method 5
gyroscope drift and bias in systems that include a gyroscope, for direction
Data Source
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AI summary
A system is for mapping an interior of a building. The system may include a mobile device having a PDR circuit configured to generate PDR positions as a user moves within the interior of the building, and a ranging circuit configured to generate ranging mapping data of the interior of the building as the user moves within the interior of the building. The system also may include a server configured to map the interior of the building and generate a location of the mobile device within the interior of the building based upon the PDR positions and the ranging mapping data from the mobile device.