Vehicle Navigation Catch-Up Processing for Delayed GNSS Updates
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Solution Overview
Problem
Existing vehicle navigation systems face challenges due to computationally intensive filter algorithms that require high-specification processors and complex operating systems, which are costly and difficult to qualify for safety critical reliability standards, leading to potential inaccuracies and instability when satellite navigation data processing is delayed.
Innovation Solution
An iterative method and system for vehicle navigation that uses a first processing element to receive satellite and inertial navigation data, stores inertial data after a validity time, and employs a catch-up process with strapdown navigation equations to iteratively update position, velocity, and attitude values, reducing the need for complex computing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex filter algorithms (e.g., Kalman filter) are used to combine satellite and inertial navigation data, then navigation accuracy and reliability are improved, but device complexity and computational requirements increase significantly
Solution Approach 1:
The patent divides the computing workload into two separate processing elements: a first processing element that performs computationally intensive filter algorithms (Kalman filter) to generate accurate navigation solutions, and a second processing element that performs simpler strapdown navigation calculations. This segmentation allows the complex filtering to be isolated to a dedicated component while enabling the main system to use simpler, more reliable computing hardware.
Solution Approach 2:
The first processing element performs preliminary computation of the navigation solution using filter algorithms before the second processing element carries out the final navigation calculations. By pre-computing the filtered navigation data, the system avoids the need for the second processing element to perform complex real-time filtering, thereby reducing overall system complexity while maintaining accuracy.
2Measurement precision
If high specification multi-core processors are used to process filter algorithms quickly, then navigation accuracy is maintained, but cost and difficulty of safety certification increase
Solution Approach 1:
The patent employs simpler, less expensive processing elements that do not require high-specification multi-core processors. By using modest computing hardware with dedicated functional separation, the system achieves the required navigation accuracy without the cost and certification burden associated with high-performance processors.
3Productivity
If complex operating systems with multi-threading capability are used to handle navigation processing, then computational speed is improved, but device complexity and safety qualification difficulty increase
Solution Approach 1:
The patent implements functional segmentation where the first processing element handles filter algorithm computations and the second processing element handles navigation calculations. This division allows each processing element to operate with simpler, more straightforward software without requiring complex multi-threaded operating systems, while still achieving the necessary computational throughput.
Data Source
AI summary
An iterative method for navigation of a vehicle includes receiving a set of satellite navigation data for the vehicle, a validity time of the set of satellite navigation data, and a series of sets of inertial navigation data. The method also includes processing the received set of satellite navigation data together with a current position, velocity and attitude value of the vehicle and a previous prediction of error states to generate an estimated position, velocity and attitude and a prediction of error states. The method further includes carrying out a catch up process and, for subsequently received sets of inertial navigation data, iteratively using each received set of inertial navigation data and the new updated position, velocity and attitude value of the vehicle to calculate a new updated position, velocity and attitude value of the vehicle.