Hybrid Navigation Module for Rotational Doppler Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current satellite location systems fail to maintain accurate positioning of mobile objects undergoing strong dynamic rotation, such as launchers, due to significant Doppler effect variations and signal interruptions, requiring high-performance inertial units and complex signal processing, which are costly and complex to implement.
Innovation Solution
A location device with a hybrid navigation module that estimates the Doppler effect by modeling the movement of the antenna and satellite, allowing the acquisition module to adjust its frequency and code search, reducing the time needed to re-acquire satellite signals and maintaining positioning during dynamic rotations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional GNSS receivers are used on mobile objects undergoing strong dynamic rotation, then positioning can be maintained under normal conditions, but the receiver fails to properly determine position when significant Doppler effect variations and signal interruptions occur
Solution Approach 1:
The system performs preliminary actions by using the inertial unit to predict and compensate for Doppler effect variations before they cause signal loss. The inertial measurements are processed in advance to prepare compensation parameters that are applied during signal acquisition, enabling the GNSS receiver to maintain tracking during dynamic rotation events.
2Reliability
If high-performance inertial units are used to maintain positioning during signal loss, then positioning can be retained during GNSS outages, but the system becomes costly and complex
Solution Approach 1:
The system merges the GNSS receiver and inertial unit into a tightly coupled integration architecture where both systems work together synergistically. The inertial unit provides motion data to compensate for Doppler variations in the GNSS signal, while the GNSS receiver provides position updates to correct inertial drift, creating a unified positioning solution that maintains continuity without requiring either component to be excessively high-performance.
3Speed
If ultra-tightly coupled integration between inertial unit and GNSS receiver is implemented, then real-time Doppler compensation is achieved, but very high performance inertial units and complex signal processing algorithms are required
Solution Approach 1:
The system changes the operational parameters of the signal processing by using inertial measurement data to dynamically adjust the expected Doppler shift parameters in the GNSS acquisition and tracking loops. This allows the receiver to focus its search and tracking in the correct frequency ranges, achieving real-time compensation without requiring overly complex algorithms or high-performance inertial sensors.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables efficient re-acquisition of satellite signals and maintains accurate positioning of mobile objects under high dynamic conditions, reducing the complexity and cost of the location device, while allowing for extended retention of location means during extreme rotations.
Implementation Method 1
an inertial unit configured to provide data relating to an acceleration and an angular velocity of the moving object
Implementation Method 2
estimating a representative value of the Doppler effect undergone by the signal emitted by the satellite as a function of the modeled movement of the antenna and of the modeled movement of the satellite
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a device (400) for locating a moving object capable of being subjected to rotational dynamics on its own axis. The device includes a receiver (410) for a satellite positioning system, an inertial unit (420), and a hybrid navigation module (430). The hybrid navigation module (430) is configured to model the movement of an antenna (54) of the receiver (410) as well as the movement of a satellite, in order to estimate a value representative of the Doppler effect to which the signal emitted by the satellite and received by the antenna is subjected. This value is sent to an acquisition module (411) of the receiver in order to facilitate reacquisition of the satellite signal following a loss of the signal caused by the rotational movement of the moving object. The movement of the antenna (54) is estimated in particular by knowing the distance separating the antenna from a centre of inertia of the moving object.