Vehicle Radar Sensor Calibration for Multiple-Reflection Interference
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Solution Overview
Problem
Radar sensors installed behind vehicle body parts experience interference due to multiple reflections between the body parts and the sensor's radome, leading to unreliable object detection.
Innovation Solution
The radar sensor is calibrated individually for each receiving channel, with interference signals caused by multiple reflections being detected and compensated during stationary operating situations, using predetermined transmission signals with precise shapes and powers, and averaging received signals over multiple cycles to generate a correction signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the radar sensor is installed behind vehicle body parts to maintain aesthetic appearance, then the external appearance of the vehicle is not altered, but interference signals from multiple reflections between the body part and radome occur
Solution Approach 1:
The patent applies preliminary action by performing calibration during stationary operating situations before normal radar operation begins. The system detects stationary objects, determines interference signals from multiple reflections, and stores correction values in advance. This preliminary calibration enables the radar to compensate for interference signals caused by the body part installation, allowing aesthetic appearance to be maintained while reducing harmful interference effects during actual operation.
2Device complexity
If the radar sensor is calibrated for all receiving channels jointly, then the calibration process is simpler, but the overall interference level remains high compared to individual channel calibration
Solution Approach 1:
The patent applies segmentation by dividing the calibration process into individual receiving channels. Each channel is calibrated separately to determine channel-specific interference signals from multiple reflections. The system processes each receiving channel independently, stores separate correction values for each channel, and applies individual compensation. This segmented approach increases calibration complexity but significantly reduces the overall interference level by accounting for channel-specific characteristics that would be lost in joint calibration.
3Loss of time
If the radar sensor uses signals from moving objects for calibration, then calibration can be performed during driving, but the signals are contaminated by Doppler shifts and varying distances
Solution Approach 1:
The patent converts the harmful effect of multiple reflections into a beneficial calibration signal. By detecting stationary objects during stationary operating situations, the system identifies interference patterns caused by multiple reflections between the body part and radome. These previously harmful interference signals become the basis for determining correction values. The system uses the predictable, stationary nature of these reflections during calibration to accurately measure and compensate for interference, then applies the same correction during moving operation when the interference patterns change.
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 approach reduces interference, enabling more accurate and reliable object detection by separating and compensating for channel-specific interference, thus improving the performance of radar sensors installed behind vehicle body parts.
Implementation Method 1
predetermined transmission signals are emitted and reflected partial signals are received
Implementation Method 2
emitted and received radar radiation to pass through largely unchanged
Implementation Method 3
received signals caused by multiple reflections between the body part and the sensor radome
Data Source
Figure 1~2b
Figure 3
Figure 4
AI summary
The invention relates to a method and to a device for reducing the influence of interference in the evaluation of at least one received signal of a radar sensor, in particular a radar sensor installed in a vehicle, by emitting predefined transmitted signals in predefined operating situations and receiving reflected partial signals and storing the signals received for the predefined operating situations in order to determine an interference spectrum and reducing the influence of interference by considering the interference spectrum in the signal evaluation.