Vehicular Positioning via IEEE 802.11 Beacon Frequency Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current GPS-based position systems suffer from inherent inaccuracies, especially in non-line-of-sight conditions such as indoors or in urban environments, and fail to provide the required relative positioning accuracy for safety applications like lane-specific information and collision avoidance, which is critical for vehicular safety.
Innovation Solution
A method and system using IEEE 802.11 standard vehicular communications to determine the relative position of one vehicle to another by receiving and processing beacon data, including frequency shift measurements and LOS/NLOS indications, to improve positioning accuracy through Angle-Of-Arrival triangulation and interpolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS is used for position determination, then absolute positioning is provided, but positioning accuracy is insufficient for safety applications
Solution Approach 1:
The patent introduces an intermediary system consisting of roadside units (RSUs) and other vehicles as mediators to improve positioning accuracy. Instead of relying solely on GPS satellites, the system uses local RSUs and neighboring vehicles to provide reference signals for triangulation and trilateration, achieving sub-meter accuracy suitable for safety applications while maintaining system reliability.
2Loss of information
If GPS signals are used, then position information is obtained, but signal blockage occurs in indoor or obstructed areas
Solution Approach 1:
The patent deploys roadside units (RSUs) as intermediary infrastructure elements that relay positioning information between GPS satellites and vehicles in obstructed areas. These RSUs act as local satellites, providing GPS signal substitution in tunnels, indoor parking lots, and urban canyons where direct satellite signals are blocked, ensuring continuous position information availability.
Solution Approach 2:
The patent merges multiple positioning approaches (GPS satellite signals, RSU-based signals, and vehicle-to-vehicle communications) into a unified positioning system. This hybrid architecture allows the system to switch between different signal sources depending on environmental conditions, maintaining position information availability whether GPS signals are clear or blocked.
3Measurement precision
If differential GPS is used, then positioning error is reduced to 3 meters, but blocked GPS signals are still not solved
Solution Approach 1:
The patent introduces roadside units (RSUs) as intermediary reference points that work in conjunction with differential GPS. These RSUs provide additional reference signals that can be used for triangulation when GPS signals are blocked, extending the effectiveness of differential positioning techniques to areas previously inaccessible to GPS-based solutions.
4Loss of time
If dead-reckoning is used, then approximate positioning is provided for short periods, but error increases with usage time
Solution Approach 1:
The patent implements a feedback mechanism where vehicles continuously exchange position information with nearby RSUs and other vehicles. This feedback loop allows the system to periodically correct dead-reckoning drift by comparing estimated positions with actual measured positions from triangulation, maintaining positioning accuracy over extended periods rather than allowing error accumulation.
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 significantly reduces combined error in determining lane positions between vehicles, enhancing relative positioning accuracy to less than 1 meter, thereby improving vehicular safety and mobility estimation, even in areas with blocked GPS signals.
Implementation Method 1
measuring frequency shift and processing the beacon data together with the frequency shift and vehicle location data to determine the position of the second vehicle relative to the first vehicle
Data Source
AI summary
The relative position of one vehicle vs. another vehicle, both driving in a vehicular environment, is determined using vehicular communications based on the IEEE 802.11 standard. The relative position determination is performed in a measuring vehicle using data provided by a measured vehicle through IEEE 802.11 communications carried through beacons as well as GPS or other location data and local map information.