Radar Target Angle Calibration via Sensor Fusion
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Solution Overview
Problem
Existing driver assistance systems face challenges in precisely determining the target angle of external objects due to systematic errors caused by installation tolerances and aging of components, which affect the accuracy of phase monopulse measurements.
Innovation Solution
A driver assistance device that calculates the target angle using a combination of distance measurements from a radar device and a separate sensor, allowing for the correction of the target angle parameter characteristic during operation, thereby reducing systematic errors and improving precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase monopulse measurement is used to determine target angle, then measurement precision is improved, but systematic errors occur due to installation tolerances and component aging
Solution Approach 1:
The system uses distance measurements from both radar and sensor to calculate target angle, then feeds back this calculated angle to correct the target angle-phase difference characteristic curve, compensating for systematic errors caused by installation tolerances and component aging
Solution Approach 2:
The system performs self-calibration by using its own distance measurement capabilities to generate correction data for the target angle characteristic curve, eliminating the need for external calibration equipment or manual adjustment
2Speed
If target angle is determined using stored characteristic curve, then determination speed is improved, but accuracy deteriorates due to curve distortion from installation tolerances and aging
Solution Approach 1:
The system pre-calculates and stores the target angle-phase difference characteristic curve for quick reference, then applies real-time corrections based on actual distance measurements to maintain accuracy without sacrificing determination speed
Solution Approach 2:
The system dynamically adjusts the stored characteristic curve parameters by applying correction values derived from actual distance measurements, transforming the static curve into an adaptive reference that maintains accuracy under varying conditions
3Measurement precision
If separate sensor is added for distance measurement, then target angle determination accuracy is improved, but device complexity increases
Solution Approach 1:
The separate sensor serves multiple functions: providing distance measurements for target angle calculation, enabling correction of the characteristic curve, and serving as a backup measurement source, thereby justifying the added component through multi-functional utility
Solution Approach 2:
The separate sensor acts as an intermediary measurement device that provides independent distance data, which is then used to mediate and correct the target angle measurements from the radar system, improving overall accuracy without requiring direct modification of the radar hardware
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 enables precise determination of the target angle with reduced systematic errors, using the high variance of distance-based calculations to filter out random errors and achieve accurate measurements over time, allowing for continuous calibration and improved system performance.
Implementation Method 1
The radar unit comprises at least one receiving antenna unit for receiving signals
Implementation Method 2
The aiming angle is determined based on the phase shift between the received signals
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to calibrating a phase monopole characteristic (I) of a radar device (3) of a driver assistance device (2). A driver assistance device (2) and a method are provided, wherein a distance (R1) of an object (10, 32) from the radar device (3) and a distance (R2) of the same object (10, 32) from a separate sensor (4) are measured. The target angle (a) is calculated from said measured values (R1, R2) according to the trilateration method. The phase monopole characteristic (I) is then corrected as a function of the result of said calculation.