GNSS Relative Positioning via Satellite Bias Exchange
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Solution Overview
Problem
Current GNSS-based methods for determining relative positions between road users, such as vehicles and infrastructure units, suffer from low accuracy due to the limitations of low-cost receivers and the inability to utilize satellite data from all visible satellites, especially in dynamic road situations, which is exacerbated by the use of pseudorange double differences that restrict data usage to common satellites.
Innovation Solution
A new approach where road users exchange sets of positioning data, including raw data and ephemeris information, to calculate relative positions using a consistent set of algorithms and error corrections, allowing for the cancellation of common errors and enabling the use of data from different satellite groups, thereby improving accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pseudorange double differences method is used to determine relative position, then calculation is simplified, but satellite data from non-common satellites cannot be utilized
Solution Approach 1:
The patent segments the relative position determination into two independent parts: (1) determining relative position using common satellites through pseudorange double differences, and (2) determining satellite-specific biases using non-common satellites. This segmentation allows each part to use its optimal data source without the constraints of the traditional unified approach.
Solution Approach 2:
The patent introduces a new dimension to the calculation by adding satellite-specific bias parameters for each satellite. This extends the traditional model that only considered relative position, enabling the system to separately account for and correct biases introduced by different satellite signals and receivers.
2Ease of manufacture
If low-cost GNSS receiver is used, then device cost is reduced, but position estimation accuracy deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where satellite-specific biases are continuously estimated from the positioning data of multiple road users and fed back to correct the relative position calculations. This closed-loop approach compensates for the inherent inaccuracies of low-cost receivers, improving measurement precision without increasing hardware cost.
Solution Approach 2:
The patent introduces satellite-specific biases as intermediary parameters that mediate between the raw measurements from low-cost receivers and the final relative position estimate. These biases act as correction factors that bridge the gap between limited hardware capabilities and high accuracy requirements.
3Extent of automation
If GNSS receiver internal algorithms are used, then position calculation is automated, but common errors between road users are distorted
Solution Approach 1:
The patent extracts the satellite-specific bias parameters from the black-box GNSS receiver algorithms and makes them explicit and可调 parameters. By taking out these hidden variables and treating them as known or estimable quantities, the system can correct for the distorting effects of internal algorithms while maintaining automation.
Data Source
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AI summary
A computer-implemented method, an apparatus, and a computer program for localizing one or more road users. The method comprises: determining a first set of parameters associated with a position of the first road user, based on a first set of positioning data associated with the first road user, the first set of positioning data obtained by a first Global Navigation Satellite System (GNSS) receiver located at the first road user; determining, for each of one or more second road users, a second set of parameters associated with a position of the second road user, based on a corresponding second set of positioning data obtained by a corresponding second GNSS receiver located at the second road user; and determining, for each of the one or more second road users, a relative position of the second road user with respect to the first road user based on the first set of parameters and a corresponding second set of parameters.