Vehicle Absolute Localisation Using Marker-Radar Distance Fusion
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Solution Overview
Problem
Existing GPS-based localization systems are vulnerable to spoofing and unreliable in challenging environments such as urban areas and tunnels, and existing marker-based systems face visibility issues and require line-of-sight detection.
Innovation Solution
A vehicle localization system using a combination of signal-emitting road side markers and passive markers, employing a processing unit and distance detection unit to calculate an accurate geographical position by combining first and second distance measures, with the latter having higher precision, utilizing IEEE 802.11p radio communication and radar detection for enhanced accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If GPS satellite measurement technique is used for geographical position measurement, then position measurement coverage is improved, but reliability deteriorates due to vulnerability to spoofing and malfunction
Solution Approach 1:
The patent introduces road side markers as intermediary objects between the vehicle and the final position calculation. These markers with known geographical positions serve as trusted reference points that the vehicle uses to determine its location, replacing direct reliance on GPS satellite signals which are vulnerable to spoofing.
Solution Approach 2:
The patent replaces the GPS satellite-based electromagnetic measurement system with a ground-based marker recognition system. Instead of relying on satellite signals, the vehicle determines position by detecting and processing signals from road side markers, substituting one measurement mechanism with another that is more reliable in challenging environments.
2Reliability
If radar reflection tracking of road side delineator posts is used, then position measurement is improved, but measurement precision deteriorates due to visibility issues and difficulty in detecting specific tags
Solution Approach 1:
The patent applies preliminary action by pre-registering the exact geographical positions of road side markers in a database before the vehicle needs to determine its location. This pre-established knowledge base allows the vehicle to quickly and accurately identify markers and calculate position without the confusion of scanning and identifying markers in real-time.
Solution Approach 2:
The system uses feedback by comparing the detected marker positions with the pre-registered database of known marker locations. This feedback mechanism allows the vehicle to verify detections, eliminate false positives, and accurately determine its position based on the correspondence between detected and registered markers.
3Reliability
If line of sight detection with remote vehicles or road side units is used, then position measurement is improved, but reliability deteriorates due to multipath signals and detection uncertainty
Solution Approach 1:
The patent uses passive road side markers that are simple, inexpensive structures with known positions. These markers serve as temporary reference points that the vehicle detects and then discards from active consideration as it moves past them, allowing the vehicle to continuously update its position based on successive marker detections without requiring complex persistent tracking.
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
Provides secure and accurate vehicle localization in difficult terrains, achieving sub-meter precision and robustness against obstructions, suitable for urban areas and tunnels.
Implementation Method 1
WO 20120154117 provides such a system, that tracks road side based delineator posts by radar reflection
Data Source
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Figure 3A~3B
AI summary
It is proposed to provide a system for localizing a vehicle in a marked environment, provided with a set of markers, e.g. on a road side, the markers emitting a position signal indicative of a respective marker's known geographical position. The system comprises a distance detection unit and a processing unit provided in the vehicle, the processing unit adapted to receive said position signal of a respective marker. The processing unit is adapted to receive said known geographical position from the position signal of said respective marker; and to estimate a first distance measure of the vehicle relative to the respective marker based on a position signal measurement. The processing unit feeds said estimated first distance measure to the distance detection unit; the distance detection unit being adapted to detect said marker within the first distance measure by a second distance measure. The distance detection unit is further adapted to provide the processing unit with the second distance measure of the vehicle relative to the detected marker and with a detection angle of the detected marker; and the localization unit calculating an instantaneous geographical position of said vehicle from the second distance measure; the detection angle and the marker's known geographical position.