Radar Sensor Icing Detection via Angle Fit Quality Analysis
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Solution Overview
Problem
Conventional methods for detecting radar sensor impairment due to icing on the radar lens or radome are ineffective, as they cannot distinguish between icing and other causes of signal attenuation, leading to unreliable angle determination and potential safety issues in driver assistance systems.
Innovation Solution
A method that uses a monotonically falling icing indicator based on angle fit qualities, with reduced weighting for objects with low signal-to-noise ratios, and a uniqueness criterion to differentiate between single-object and overlapping signal peaks, allowing for the detection of icing-induced angle blindness without false positives from dirt or other causes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional methods using average angle quality are used to detect radar sensor impairment, then the detection method is simple, but it cannot distinguish between icing and other causes of signal attenuation leading to unreliable detection
Solution Approach 1:
The patent segments the detection task by separating objects into different groups based on their angle fit qualities and signal-to-noise ratios. It divides objects into a first group with high angle fit qualities and high signal-to-noise ratios, and a second group with low angle fit qualities and low signal-to-noise ratios. This segmentation allows the system to focus on specific object characteristics to detect icing without being misled by other causes of signal attenuation.
Solution Approach 2:
The patent applies local quality by evaluating specific characteristics of individual objects (angle fit quality and signal-to-noise ratio) rather than using a single aggregate metric. By examining the local properties of objects in the radar scene, the system can identify patterns that indicate icing conditions without relying on conventional average angle quality metrics that conflate multiple causes of impairment.
2Productivity
If all detected objects are used equally in angle quality calculation, then the calculation is simple, but objects with low signal-to-noise ratio create false positives for icing detection
Solution Approach 1:
The patent applies partial action by selectively using only a subset of objects (the first group with high angle fit qualities and high signal-to-noise ratios) for icing detection rather than processing all detected objects. This partial approach maintains processing efficiency while filtering out objects that would cause false positives, such as those with low signal-to-noise ratios that may indicate other types of impairment rather than icing.
3Duration of action of stationary object
If the radar sensor continues operating with potential icing, then system availability is maintained, but angle determination becomes unreliable affecting driver assistance functionality
Solution Approach 1:
The patent implements feedback by continuously monitoring angle fit qualities and signal-to-noise ratios of detected objects to detect icing conditions. When icing is detected through the evaluation of these parameters, the system provides feedback to trigger counter-measures such as warnings to the driver, self-deactivation of the system, or mode changes. This feedback loop allows the radar sensor to maintain operation while detecting and responding to deteriorating measurement precision caused by icing.
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
Enables reliable detection of icing on the radar sensor, preventing system impairment by triggering appropriate counter-measures such as warning, self-deactivation, or mode changes, and allowing for ice removal through heating or vibration.
Implementation Method 1
since such a layer of ice has a refractive index that is different from the refractive index of air, it may lead, similarly to the radar lens itself, to a refraction and hence to a change in the direction of the radar radiation
Data Source
AI summary
A method for detecting icing at an angle-resolving radar sensor in a driver assistance system for motor vehicles, in which signals of a plurality of antenna elements each having a specific angle characteristic are compared with the corresponding angle characteristics, and the azimuth angle of a located object is determined on the basis of an angle fit quality which indicates how well the signals of the antenna elements correspond to the angle characteristics for a given azimuth angle, wherein an indicator for icing is formed which is a monotonically falling function of the angle fit qualities of the located objects, with objects having a low signal-to-noise ratio being included in the indicator at the most with a reduced weighting.