Kinematic Positioning With Inertial Constraints During GNSS Outages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
GNSS-based RTK positioning systems experience significant accuracy and performance degradation during signal outages due to environmental blockages, leading to temporary loss of GNSS signals and RTK carrier phase measurements.
Innovation Solution
Incorporating inertial measurement unit (IMU) data to generate position update inputs for the kinematic positioning engine during signal outages, using IMU constraints such as height constraints derived from a transition matrix to maintain positioning accuracy through a Kalman filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GNSS-based RTK positioning is used, then positioning precision is improved, but reliability deteriorates during signal outages
Solution Approach 1:
The patent merges GNSS RTK positioning with IMU inertial navigation to create a hybrid positioning system. During signal outages, the IMU provides continuous positioning estimates by integrating acceleration measurements, while GNSS resumes updating the system when signals are available, maintaining both precision and reliability across all conditions
Solution Approach 2:
The IMU acts as an intermediary system that bridges gaps in GNSS signal availability. The inertial measurement unit provides intermediate positioning estimates during outages, allowing the positioning system to maintain continuity without direct GNSS input, thus resolving the reliability issue during signal blockages
2Reliability
If IMU data is integrated to maintain positioning during outages, then reliability is improved, but device complexity increases
Solution Approach 1:
The IMU serves multiple functions: it provides positioning estimates during GNSS outages, supplies attitude information for antenna orientation correction, and offers velocity measurements for Doppler compensation. This multi-functionality justifies the added complexity by delivering comprehensive positioning enhancement across various operational scenarios
3Stability of the object's composition
If inertial constraints are applied to maintain positioning accuracy, then positioning stability is improved, but measurement precision may deteriorate due to error accumulation
Solution Approach 1:
The system employs periodic correction where IMU-based inertial constraints are applied during GNSS outages, and GNSS measurements periodically reset and correct the accumulating inertial errors when signals become available. This periodic alternation maintains stability during outages while preventing long-term precision degradation through regular recalibration
Data Source
AI summary
Systems and techniques are provided for determining positioning. For example, the systems and techniques can include obtaining an inertial height measurement, wherein the inertial height measurement is obtained based on a determination that one or more positioning signals are unavailable. A height constraint can be generated using the inertial height measurement, wherein the height constraint is generated based at least in part on a transition matrix. One or more positioning measurements can be determined based on using the height constraint as a real-time kinematic (RTK) positioning input.