Azimuth Angle Calculation Using Multi-Baseline GNSS Verification
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Solution Overview
Problem
Conventional methods for calculating the azimuth angle of a movable body using GNSS signals are complex and time-consuming, and are prone to errors due to the use of magnetic sensors, especially in environments with metal components and strong magnetic fields, leading to inaccurate initial value calculations.
Innovation Solution
An azimuth angle calculating device with at least three antennas arranged non-linearly, an initial value setting module, an integer value bias determining module, a base-line vector calculating module, and a verifying module, which performs multiple base-line verification to securely and quickly determine the initial azimuth angle without complex processing like Kalman filters, eliminating the need for magnetic sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic sensor is used to set the initial azimuth angle, then the initial value can be obtained, but the error increases in environments with metal components or strong magnetic fields
Solution Approach 1:
The patent removes the magnetic sensor from the system entirely, extracting the harmful dependency on magnetic field measurements. Instead of using magnetic sensors to determine the initial azimuth angle, the system relies solely on GNSS carrier phase measurements from multiple antennas, thereby eliminating the source of magnetic interference errors.
Solution Approach 2:
The patent replaces the magnetic sensing mechanism with a GNSS-based carrier phase measurement mechanism. Rather than detecting magnetic field directions, the system uses the phase differences of GNSS signals received by multiple antennas to calculate the initial azimuth angle, substituting a non-magnetic measurement approach.
2Measurement precision
If Kalman filter is used for floating ambiguity estimation, then the estimation can be performed, but the calculation time increases
Solution Approach 1:
The patent segments the ambiguity resolution process into multiple independent baseline calculations rather than using a unified Kalman filter approach. By dividing the antenna system into multiple baseline pairs and calculating integer biases independently for each baseline, the system avoids the computational burden of filtering while maintaining accuracy through cross-verification.
Solution Approach 2:
The patent implements a verification mechanism where multiple baseline calculations provide feedback to confirm the correctness of the integer bias. By calculating baselines from different antenna pairs and verifying their consistency, the system ensures accurate ambiguity resolution without requiring time-consuming filtering operations.
3Measurement precision
If a movable antenna is used for attitude angle measurement, then the measurement can be performed, but the mechanism becomes complicated
Solution Approach 1:
The patent merges the functions of multiple fixed antennas into a single measurement system. Instead of using one movable antenna that changes position, the system combines the signals from multiple fixed antennas arranged in a specific geometry, achieving attitude angle measurement through signal processing rather than mechanical movement.
Solution Approach 2:
The patent replaces the mechanical antenna movement system with a fixed multi-antenna array. Rather than physically moving a single antenna to change measurement baselines, the system uses multiple fixed antennas with predetermined positions, substituting mechanical complexity with a static geometric configuration and corresponding signal processing algorithms.
Data Source
AI summary
A plurality of antennas may be arranged at positions non-linear to each other. Processing circuitry may set an initial value of one of an attitude angle and an azimuth angle of an azimuth angle calculating device. An integer value bias of a carrier phase difference between at least two groups of antennas may be determined by using the initial value. A base-line vector between the at least two groups of antennas may be calculated by using the integer value bias corresponding to the group of antennas. A multiple base-line verification may be performed, in which validity of the initial value is verified by using each of the base-line vectors calculated using the integer value bias. An azimuth angle may be calculated by using the integer value bias when the multiple base-line verification is successful.