Radar Sensor Self-Calibration Using Road Surface Responses
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Solution Overview
Problem
Existing methods for determining the mounting position of a radar sensor in vehicles require factory calibration and the presence of special targets, leading to increased costs and complexity.
Innovation Solution
A method utilizing radar responses from the road surface to iteratively adapt a linear function to peak amplitudes, estimating the mounting position without factory calibration or external targets, by restricting the field of view and performing iterative adjustments to achieve accurate mounting height and angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If factory alignment with special equipment and trained experts is used to estimate mounting position, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The radar sensor performs self-calibration by using the road surface as a natural reference target. The system automatically determines mounting position parameters through iterative optimization of a predefined model against radar responses from the road surface, eliminating the need for external calibration equipment and trained experts.
Solution Approach 2:
The invention replaces expensive, complex factory calibration equipment with a simple, readily available alternative - the road surface itself. This natural reference target is free, universally available, and requires no special preparation or maintenance.
2Adaptability or versatility
If online calibration with targets of opportunity is performed, then mounting position can be adjusted during vehicle life time, but additional cost for radar system increases
Solution Approach 1:
The radar sensor serves dual functions: primary detection of hazardous objects and secondary self-calibration of mounting position. The same radar responses used for object detection are also utilized for determining mounting position parameters, eliminating the need for separate calibration functionality.
Solution Approach 2:
The system performs continuous self-calibration during normal operation by repeatedly optimizing the predefined model against road surface radar responses. This automatic adjustment capability allows the mounting position to be updated throughout the vehicle's lifetime without external intervention or additional cost.
3Measurement precision
If factory alignment is performed during manufacturing, then initial mounting position accuracy is improved, but additional cost and time are required
Solution Approach 1:
The system performs preliminary rough alignment during factory manufacturing, which is sufficient for initial operation. The precise mounting position parameters are then automatically refined through iterative model optimization during normal vehicle operation, eliminating the need for time-consuming precision calibration during manufacturing.
Solution Approach 2:
The mounting position parameters are treated as dynamic values that can be continuously updated during vehicle operation. Rather than being fixed after factory calibration, the parameters are repeatedly optimized based on real-time radar responses from the road surface, allowing the system to adapt and improve accuracy over time.
Data Source
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AI summary
A method is provided for determining a mounting position of a radar sensor at a vehicle. The mounting position is defined with respect to a ground plane on which the vehicle is currently located. Radar responses captured by the radar sensor are received, wherein an field of view of the radar sensor covers at least a predefined area of the ground plane. A sequence of characteristics of the radar responses is determined, and the mounting position is determined by performing the steps of: optimizing parameters of a predefined model with respect to the sequence of characteristics of the radar responses, and determining the mounting position based on the optimized parameters of the predefined model.