Hybrid GPS INS Carrier Phase Cycle Slip Detection
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Solution Overview
Problem
GPS systems face inaccuracies due to temporary carrier loss and inertial navigation systems (INS) accumulate errors over time, making them insufficient for critical applications requiring precise and consistent location information, such as vehicle refueling or supply exchange operations.
Innovation Solution
Combining GPS and INS systems to detect and correct GPS cycle slips by using INS to determine and correct GPS position calculation errors, ensuring accurate and stable position measurements without error accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS carrier phase measurement is used to achieve high position accuracy, then position precision is improved, but temporary loss of location information occurs due to carrier tracking loop discontinuity
Solution Approach 1:
The patent introduces an inertial navigation system (INS) as an intermediary to bridge GPS signal interruptions. The INS independently calculates position using accelerometers and gyroscopes, providing continuous position estimates during GPS outages. This mediator system ensures that location information remains available even when carrier phase measurement fails, resolving the contradiction between high precision and continuous reliability.
Solution Approach 2:
The system pre-integrates INS data with GPS measurements during normal operation, building a cushion of predictive capability. When GPS carrier phase measurement fails, the pre-synchronized INS data immediately compensates for the loss, preventing gaps in location information. This beforehand preparation allows the system to maintain both high accuracy and continuity.
2Reliability
If INS is used to eliminate temporary carrier loss, then continuity of location information is improved, but position accuracy deteriorates due to error accumulation over time
Solution Approach 1:
The patent merges GPS and INS systems into a hybrid navigation system that combines their complementary strengths. GPS provides high-precision position updates when available, while INS provides continuous position estimates when GPS is interrupted. The system dynamically weights and integrates data from both sources, ensuring that the combined output maintains high accuracy during GPS operation and continuous reliability during GPS outages, thereby resolving the contradiction between precision and continuity.
Solution Approach 2:
The system dynamically changes the weighting parameters of GPS and INS data based on signal quality and operational context. When GPS carrier phase measurement is reliable, the system prioritizes GPS data for high precision. When GPS signal is lost or degraded, the system shifts weight to INS data to maintain continuity. This parameter adaptation allows the system to optimize for accuracy or continuity depending on real-time conditions.
3Reliability
If GPS code phase resolution is used instead of carrier phase measurement, then reliability is improved by avoiding carrier loss, but position precision deteriorates to meter-level accuracy
Solution Approach 1:
The patent creates a multi-functional position determination system that can operate in multiple modes depending on signal conditions. The system universally processes both GPS code phase and carrier phase measurements, as well as INS data, adapting its primary measurement source based on availability and quality. This multi-functionality allows the system to achieve high precision when carrier phase is available, maintain stability when using code phase, and ensure continuity through INS, thereby resolving the precision-stability trade-off.
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AI summary
An apparatus comprising a position system configured to determine a global positioning (GPS) change vector, and an inertial navigation system (INS) change vector. The position system is configured to determine a relative position between a first platform and a second platform based on the GPS change vector and the INS change vector, and the position system is configured to correct a GPS position calculation error based on the GPS change vector and the INS change vector.