Flight Vehicle Position Estimation Using Adaptive Sensor Fusion
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Solution Overview
Problem
Small flight vehicles face challenges in accurately estimating their position due to low precision inertial sensors and GPS receiver limitations, especially in areas where GPS reception is difficult, leading to suboptimal flight control.
Innovation Solution
A device and method that utilize a combination of an inertial sensor and multiple position estimation systems, including GPS receivers, imaging devices, barometers, and ultrasonic sensors, to enhance position estimation accuracy by integrating and filtering sensor data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS receiver is used for position estimation, then position estimation accuracy is improved in open areas, but position estimation reliability deteriorates in areas with difficult GPS reception
Solution Approach 1:
The patent combines GPS receiver with inertial sensor to create a hybrid position estimation system. The GPS provides absolute position data when available, while the inertial sensor provides continuous position data through integration of acceleration measurements. The system merges these two data sources to maintain position estimation reliability in both open areas and areas with difficult GPS reception.
Solution Approach 2:
The patent dynamically changes the weighting parameters in the complementary filter based on GPS signal quality. When GPS reception is good, the filter gives higher weight to GPS data for improved accuracy. When GPS reception deteriorates, the filter automatically increases weight on inertial sensor data to maintain reliability, thus adapting to varying environmental conditions.
2Reliability
If inertial sensor is used for position estimation, then position estimation can be performed in areas with difficult GPS reception, but position estimation accuracy deteriorates due to low sensor precision and error accumulation
Solution Approach 1:
The patent implements feedback through the complementary filter that continuously processes inertial sensor data and compares it with GPS data when available. The filter uses the difference between predicted position (from inertial integration) and actual GPS position to correct drift and accumulate error, feeding this correction back into the position estimation to maintain accuracy over time.
Solution Approach 2:
The system merges inertial sensor data with GPS data through a complementary filter. The inertial sensor provides high-frequency position updates and works independently of GPS signal availability, while GPS provides periodic absolute position references. The combination allows the system to maintain both reliability (through inertial continuity) and accuracy (through GPS correction).
3Reliability
If multiple position estimation systems are combined, then position estimation reliability is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal complementary filter that can process data from multiple position estimation systems (GPS receiver and inertial sensor) through a unified mathematical framework. This multi-functional approach allows the same filter structure to handle different sensor types and data formats, reducing overall system complexity despite combining multiple estimation systems.
Data Source
AI summary
Provided is a device including an acquisition unit that acquires information indicating a position estimation system selected from among a plurality of position estimation systems for estimating a position of a flight vehicle, and a position estimation unit that estimates the position of the flight vehicle from first information generated by using an inertial sensor of the flight vehicle and second information generated through the position estimation system based on a parameter for the position estimation system.