Portable Terminal Position Compensation Using Motion Sensors and Map Matching
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Solution Overview
Problem
Portable terminals using Global Navigation Satellite Systems (GNSS) struggle to accurately estimate position information in shadow zones, such as indoors or in built-up areas, due to multi-path delays, signal attenuation, and interference, leading to estimation errors.
Innovation Solution
The method involves a portable terminal that compensates for position estimation errors using motion information from sensors like acceleration, geomagnetic, and gyroscope sensors, and a map matching scheme to improve accuracy in GNSS shadow zones, by selectively applying first and secondary compensations based on the reliability of GPS signals and map data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GNSS is used to estimate position information, then position estimation can be performed in open areas, but accurate position estimation cannot be achieved in shadow zones such as indoors or built-up areas
Solution Approach 1:
The patent introduces motion information from sensing modules (acceleration sensor, geomagnetic sensor, gyroscope sensor) as an intermediary to compensate for GNSS position estimation errors. The motion information serves as a mediator that bridges the gap between GNSS measurements and actual position, allowing the system to correct errors caused by multi-path delays and signal attenuation in shadow zones
Solution Approach 2:
The patent changes the parameters used for position estimation by incorporating motion information (acceleration, geomagnetic field, gyroscope data) alongside GNSS data. This parameter change enables the system to compensate for estimation errors dynamically, improving accuracy in shadow zones where traditional GNSS alone fails
2Measurement precision
If motion information and map matching are used to compensate position estimation errors, then position accuracy in shadow zones improves, but system complexity increases
Solution Approach 1:
The patent makes the sensing module serve multiple functions: it detects motion information for compensation, provides navigation data, and enables map matching operations. By making the sensing module universal, the patent avoids adding separate dedicated compensation hardware, thereby managing system complexity while achieving improved position accuracy in shadow zones
Data Source
AI summary
An apparatus and a method for estimating position information in a portable terminal are provided. A position estimation method includes estimating position information of the portable terminal; firstly compensating for an estimation error of the position information of the portable terminal according to motion information of the portable terminal; secondarily compensating for the firstly compensated position information according to a map matching scheme; and storing the position information of the compensated estimation error as the position information of the portable terminal.