Accelerometer-Only GNSS Enhancement via Dynamic State Assessment
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Solution Overview
Problem
Low-cost, uncalibrated, and unaligned accelerometers in devices like cell phones hinder the integration of inertial navigation systems (INS) with Global Navigation Satellite Systems (GNSS), limiting their performance in satellite navigation and tracking due to the need for accurate alignment and calibration.
Innovation Solution
A method using accelerometer-only data to assess the dynamic state of a platform, allowing for gross-calibration and categorization of acceleration levels, which enhances satellite navigation and tracking algorithms without requiring INS integration, by detecting stationary conditions and utilizing categorized data to adjust parameters such as bandwidth and integration intervals for improved sensitivity and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full INS integration with calibrated and aligned sensors is used, then navigation accuracy is improved, but device complexity and calibration requirements increase
Solution Approach 1:
The patent extracts only the essential accelerometer data without requiring full INS integration, calibration, or alignment. It uses a simplified approach that takes raw accelerometer measurements and processes them directly to enhance GNSS performance, eliminating the need for complex sensor calibration and alignment procedures while maintaining navigation accuracy improvements
Solution Approach 2:
The patent applies partial action by using only accelerometer data without requiring the complete INS sensor suite (gyroscopes, magnetometers, etc.). It processes a subset of sensor data (accelerometer only) to achieve the desired GNSS enhancement, avoiding the complexity of full INS integration while still providing meaningful navigation improvements
2Device complexity
If low-cost accelerometers without calibration are used, then device complexity is reduced, but navigation performance is limited
Solution Approach 1:
The patent embraces the use of low-cost, uncalibrated accelerometers by processing their raw data directly without requiring calibration or alignment. The system accepts the limitations of these inexpensive sensors and develops algorithms that work effectively with their inherent characteristics, achieving GNSS enhancement without the need for expensive calibrated sensor systems
Solution Approach 2:
The patent changes the processing parameters and algorithms to accommodate uncalibrated accelerometer data. By adjusting the signal processing approaches, noise filtering characteristics, and data fusion algorithms, the system optimizes performance specifically for raw accelerometer measurements, transforming a limitation into an opportunity for simplified, robust processing
3Ease of operation
If accelerometer data is processed without INS integration, then ease of operation is improved, but measurement precision deteriorates
Solution Approach 1:
The patent extracts and processes only the accelerometer component of motion data, separating it from the more complex INS integration requirements. By focusing solely on accelerometer measurements and their temporal patterns, the system achieves ease of implementation while maintaining sufficient precision for GNSS enhancement through simplified data processing
Data Source
AI summary
The present invention provides apparatus and methods for improving satellite navigation by assessing the dynamic state of a platform for a satellite navigation receiver and using this data to improve navigation models and satellite tracking algorithms. The dynamic state of the receiver platform may be assessed using only accelerometer data, and does not require inertial navigation system integration. The accelerometers may not need to be very accurate and may not need to be aligned and/or accurately calibrated.