Satellite Selection Device for Stable Positioning

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Solution Overview

Problem

Conventional positioning systems select satellites on a per-time basis, leading to unstable positioning due to short satellite usage durations, which results in large errors and inability to perform precise positioning, especially when the number of channels and computation load are restricted.

Innovation Solution

A positioning satellite selection device that determines a selection combination of satellites based on a quality evaluation and precision degradation index, ensuring satellites are selected for longer than the shortest required time, using a plan creation unit to optimize satellite selection and storage for stable positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If satellites are selected on a per-time basis to optimize positioning precision, then positioning accuracy is improved, but satellite usage duration becomes too short to reduce errors, resulting in unstable positioning

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsatellite usage duration
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The system performs preliminary evaluation of satellite quality metrics (signal-to-noise ratio, elevation angle, observation value quality) before final selection. This allows the system to pre-identify suitable satellites that can maintain stable usage for error reduction, rather than making reactive selections that cause frequent changes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention ensures continuous usage of selected satellites by implementing a minimum usage duration threshold and avoiding frequent reselection. The system maintains satellite selection stability over time, allowing error reduction to occur continuously through prolonged observation of the same satellites

Inventive Principle:
Principle #20Continuity of useful action

2Measurement precision

If the number of satellites to be used is increased to improve positioning quality, then positioning precision is improved, but the number of required channels and computation load increase

Engineering Contradiction:
Improvepositioning precisionVSAvoidnumber of channels and computation load
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system changes selection parameters by using quality metrics (signal-to-noise ratio thresholds, elevation angle minimums, observation value quality standards) to evaluate and select satellites. This parameter-based selection achieves optimal positioning precision with a controlled number of satellites, avoiding unnecessary increases in system complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention evaluates multiple satellites beyond the minimum required number but selects only those meeting quality criteria. This partial selection approach ensures sufficient satellites are considered for optimal precision while limiting the final count to manage channel and computation constraints

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If satellites with poor quality observation values are excluded to improve positioning accuracy, then positioning precision is improved, but the number of available satellites decreases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidnumber of available satellites
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The system applies quality thresholds (signal-to-noise ratio, elevation angle, observation value quality) as selection parameters. Satellites meeting these parameters are included, while those below thresholds are excluded. This parameter-based filtering maintains positioning accuracy by excluding poor-quality satellites while preserving the maximum possible number of usable satellites

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3351969B1Positioning satellite selection device
Publication Date: 2022.05.11 MITSUBISHI ELECTRIC CORP
  • EP3351969B1 patent drawingFigure 1
  • EP3351969B1 patent drawingFigure 2
  • EP3351969B1 patent drawingFigure 3

AI summary

A positioning satellite selection device that obtains, from signals transmitted from a plurality of positioning satellites, a selection combination of positioning satellites to be used for positioning at a position of a positioning target, and includes: a positioning data acquisition unit (111) that acquires positioning data which is navigation information, a range observation value, and an error correction value of this range observation value of a positioning satellite; a satellite position calculation unit (112) that calculates a satellite position of the positioning satellite from the navigation information of the positioning data; a quality evaluation unit (114) that evaluates quality of the positioning data; a shortest time designation unit (115) that sets a shortest selection time which is a shortest time during which the positioning satellite is selected to a larger value as the quality is poorer; a plan creation unit (113) that obtains the selection combination by selecting a positioning satellite on the condition of selecting for longer than the shortest selection time; and a plan storage unit (117) that stores a plan of the selection combination of positioning satellites.