Tilted IMU Calibration for Accurate 3D Vehicle Navigation
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Solution Overview
Problem
Existing inertial measuring units in vehicles, especially land vehicles, face challenges in accurate calibration due to limited dynamics along or around vehicle axes, making reliable 3D position and orientation estimation difficult during driving.
Innovation Solution
The system employs a tilted inertial measuring unit with sensor axes aligned orthogonally to the vehicle's main direction, utilizing additional detection devices to provide calibration data, allowing for accurate calibration of all sensor axes during vehicle movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If sensor axes are aligned along vehicle main axes, then installation is simple, but calibration accuracy deteriorates due to limited dynamics exposure
Solution Approach 1:
The sensor axes are tilted relative to the vehicle's main axes, introducing a dimensional change in the orientation of the sensing elements. This tilting ensures that all sensor axes are exposed to significant accelerations in multiple directions during normal vehicle operation, thereby improving calibration accuracy without complicating the installation process
2Quantity of substance
If inexpensive sensors are used, then cost is reduced, but calibration complexity increases due to need for continuous calibration
Solution Approach 1:
The system enables self-calibration of inexpensive sensors during normal vehicle operation by utilizing the vehicle's own movement dynamics. The calibration process uses data from the sensors themselves and additional detection devices, allowing continuous automatic calibration without requiring external equipment or manual intervention, thus managing calibration complexity while using cost-effective sensors
3Measurement precision
If 3D position and orientation estimation is implemented, then navigation accuracy is improved, but sensor calibration requirements become more stringent
Solution Approach 1:
The system performs preliminary calibration of all sensor axes during normal vehicle operation before navigation calculations are executed. By continuously determining calibration parameters using the tilted sensor arrangement and additional detection devices, the system ensures that accurate 3D position and orientation estimation can be achieved without requiring extremely precise manufacturing tolerances
Data Source
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AI summary
The invention relates to a system for checking an inertial measurement unit (IMU) of a vehicle (V), in particular a land vehicle, while driving, wherein the inertial measurement unit (IMU) has a first acceleration sensor for measuring a translational acceleration along a first sensor axis and/or a first yaw rate sensor for measuring a yaw rate about the first sensor axis, and a second acceleration sensor for measuring a translational acceleration along a second sensor axis and/or a second yaw rate sensor for measuring a yaw rate about the second sensor axis, wherein a detection device is provided for detecting a movement of the vehicle (V) in a first vehicle direction and/or about the first vehicle direction, characterized in that both the first and the second sensor axis are tilted relative to the first vehicle direction.