Wireless Signal SLAM for Position Correction in Changing Environments
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Solution Overview
Problem
Current SLAM technologies face challenges in accurately estimating the position of a moving node and creating detailed maps in dynamic wireless environments, such as those with signal interference or limited access points, without requiring separate sensors for physical landmarks, and struggle to provide accurate indoor and outdoor localization.
Innovation Solution
A SLAM method that estimates relative positions based on motion sensing and generates change patterns of signal strength over time, correcting positions using signal strength distributions, and creates maps by representing routes with corrected coordinates, utilizing wireless communication signals like Wi-Fi and LTE without the need for physical landmarks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If LiDAR is used for high-resolution landmark identification, then measurement precision is improved, but device complexity and cost increase, making it difficult to miniaturize for smartphones
Solution Approach 1:
The patent replaces physical landmark-based SLAM (which requires specialized sensors like LiDAR) with wireless signal-based SLAM. Instead of using mechanical/optical sensors to detect physical landmarks, the system uses wireless communication signals (Wi-Fi, LTE) to identify and track virtual landmarks (access points and base stations), thereby eliminating the need for complex miniaturization of specialized sensors while maintaining positioning functionality
Solution Approach 2:
The patent makes the wireless communication module serve dual functions: both wireless communication and landmark identification for SLAM. The same antenna and receiver used for communication also detect signal strengths of access points and base stations, which are then used as virtual landmarks for positioning, eliminating the need for separate specialized sensors
2Measurement precision
If camera is used for landmark identification, then measurement precision is improved, but device complexity increases due to high image data processing requirements
Solution Approach 1:
The patent substitutes optical image processing with wireless signal processing. Instead of capturing and processing complex image data to identify physical landmarks, the system measures wireless signal strengths from access points and base stations, which are then used to determine position. This replaces computationally intensive image processing with simpler signal strength measurement and comparison
Solution Approach 2:
The patent uses readily available wireless communication infrastructure (Wi-Fi access points and LTE base stations) as virtual landmarks instead of requiring specialized camera systems. These existing infrastructure elements serve as free, easily accessible landmarks that eliminate the need for expensive camera hardware and processing capabilities
3Area of stationary object
If GPS is used for localization, then positioning coverage is improved, but reliability deteriorates in indoor spaces and urban areas with signal blocking
Solution Approach 1:
The patent introduces wireless access points and base stations as intermediary virtual landmarks that can penetrate indoor environments and urban canyons where satellite signals are blocked. These intermediaries relay positioning information by providing measurable signal strengths that work reliably in GPS-denied environments while maintaining connection to the broader positioning system
Solution Approach 2:
The patent dynamically adapts the positioning system to work in both outdoor GPS-available environments and indoor GPS-denied environments by using the same wireless signal measurement mechanism for both scenarios. The system transitions smoothly between using satellite-based GPS and infrastructure-based wireless signals depending on environmental conditions, maintaining continuous positioning capability
4Ease of operation
If traditional wireless localization is used, then ease of operation is improved, but measurement precision deteriorates due to low localization accuracy
Solution Approach 1:
The patent implements feedback through continuous measurement and comparison of wireless signal strengths over time. The system measures signal strengths from multiple access points and base stations, compares current measurements with historical data and signal strength distributions, and uses this feedback to continuously refine position estimates, thereby improving accuracy while maintaining ease of operation
Solution Approach 2:
The patent performs preliminary actions by pre-establishing signal strength distributions for multiple access points and base stations before actual positioning is needed. These pre-collected signal characteristics are stored and used as reference data during positioning operations, enabling accurate location determination without requiring real-time complex calculations
Data Source
AI summary
The present invention relates to SLAM (simultaneous localization and mapping) method and apparatus robust to a wireless environment change. A relative position of a moving node is estimated based on motion sensing of the moving node, the relative position of the moving node is corrected based on a comparison between a change pattern of at least one signal strength received over a plurality of time points and a signal strength distribution in a region in which the moving node is located, a route of the region is represented by using the relative position corrected as described above, and thereby, it is possible accurately estimate a position of the moving node and to create a map in which very accurate route information is recorded throughout the entire region at the same time, even if a wireless environment change such as signal interference between communication channels, expansion of an access point, and occurrence of a failure or an obstacle is made or a poor wireless environment such as lack of the number of access points occurs.