Rail Vehicle Sensor Layout for GNSS Spoofing-Resistant Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position determination systems for rail vehicles, such as those using GNSS, are prone to errors due to spoofing and distortion, especially in low-speed or tunnel conditions, leading to potential hazards and accidents.
Innovation Solution
A sensor arrangement with at least two sensors positioned transversely to the direction of travel on a rail vehicle, which measure position speeds and process them to enhance position determination accuracy, including the use of incremental distance indicators, optical, or inductive sensors, and dual radars, to calculate central speed, angular velocity, or average speed, and compare these with GNSS data to detect spoofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GNSS data is used for position determination, then position information can be obtained, but the data can be distorted by spoofing leading to incorrect position calculations
Solution Approach 1:
The system continuously monitors position speeds from multiple sensors and compares them against each other and against speeds derived from GNSS data. This feedback mechanism allows the system to detect inconsistencies caused by spoofing and to identify when GNSS data may be compromised, thereby maintaining reliable position determination even under attack
Solution Approach 2:
The patent introduces position speed measurements from independent sensors (incremental distance indicators, optical sensors, inductive sensors) as intermediary variables. These measurements serve as a mediator between the potentially compromised GNSS data and the final position calculation, allowing the system to verify GNSS integrity through cross-comparison of speed data from multiple sources
2Measurement precision
If a single position speed is used for position determination, then the system is simpler, but the position determination is less accurate especially when traveling around curves
Solution Approach 1:
The system segments the position determination task by placing sensors at multiple discrete positions transverse to the direction of travel. Each sensor measures position speed at its specific location, and these segmented measurements are then integrated to calculate central speed and angular velocity, providing accurate position determination for the entire vehicle
Solution Approach 2:
The patent transitions from one-dimensional speed measurement (single point) to two-dimensional speed field measurement (multiple transverse positions). By measuring position speeds across the transverse dimension and using these to calculate angular velocity and central speed, the system achieves accurate position determination that accounts for the vehicle's orientation and curved path motion
3Measurement precision
If incremental distance indicators connected through rigid axle are used, then the system is simpler, but the values are distorted when traveling around a curve because the outer wheel travels a greater distance than the inner wheel
Solution Approach 1:
The patent extracts the incremental distance indicators from the rigid axle connection and places them on independent wheels. This separation allows each wheel to rotate independently without being constrained by a rigid mechanical link, enabling accurate position speed measurements even when wheels travel different distances around curves
Solution Approach 2:
The system transitions from a static rigid axle connection to a dynamic independent wheel configuration. Each wheel with its incremental distance indicator can adapt its rotation independently to the actual distance traveled, allowing the system to dynamically capture accurate position speed data for each wheel location without mechanical distortion from rigid coupling
Data Source
AI summary
A sensor arrangement for position determination of a rail vehicle includes at least two sensors that can be attached to the rail vehicle. Each of the sensors is configured to ascertain a position speed and to be disposed on the rail vehicle at different positions transverse to the direction of travel. At least one processing apparatus which is connected to the sensors is configured to process the position speeds ascertained by the sensors. An apparatus for position determination of a rail vehicle, a rail vehicle, and a method for position determination for a rail vehicle are also provided.