FMCW Radar Pairing Using Peak Frequency Change Rates
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Solution Overview
Problem
Existing FMCW radar devices face pairing errors due to numerous reflections in on-vehicle environments, leading to erroneous detection of non-existent targets or failure to detect existing ones, particularly when vehicles accelerate or decelerate, as current methods rely on peak intensity or assume linear uniform motion.
Innovation Solution
An FMCW radar device that generates beat frequency distributions during up-chirp and down-chirp periods, calculates peak frequency change rates, and pairs frequencies based on temporary ranges calculated using these rates, ensuring accurate pairing by comparing differences within a set threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pairing is performed based on peak intensity, then pairing can be performed simply, but erroneous pairing occurs when multiple reflections have near peak intensities
Solution Approach 1:
The patent changes the pairing parameter from peak intensity to peak frequency and its temporal variation. By using the change rate of peak frequency over time and calculating temporary ranges based on this change rate, the system achieves more reliable pairing that is not affected by multiple reflections with similar intensities.
2Measurement precision
If beat frequency tracking is performed to calculate range and range change rate before pairing, then pairing accuracy is improved, but the method assumes linear uniform motion and fails when vehicles accelerate or decelerate
Solution Approach 1:
The patent introduces dynamic adaptation by continuously calculating the change rate of peak frequency in the current processing period and comparing it with the previous processing period. This dynamic approach allows the system to adapt to accelerating or decelerating motion by using the actual observed frequency changes rather than assuming uniform linear motion.
Solution Approach 2:
The patent performs preliminary calculation of temporary ranges using the change rate of peak frequency before performing the pairing operation. This preliminary action of calculating expected range values based on frequency change rates enables the system to prepare accurate reference values for pairing, improving both accuracy and adaptability to non-linear motion.
3Quantity of substance
If multiple reflections are present in the environment, then the radar can detect more objects, but pairing errors increase due to the large number of reflections
Solution Approach 1:
The patent uses feedback by continuously tracking the change rate of peak frequency over time and using this information to calculate temporary ranges for pairing decisions. This feedback mechanism allows the system to distinguish between real targets and spurious reflections by verifying whether the observed frequency changes are consistent with the calculated temporary ranges, thereby maintaining high pairing accuracy even with multiple reflections present.
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 significantly reduces pairing errors by accurately pairing peak frequencies and calculating relative velocities and range change rates, even in non-linear motion scenarios, enhancing the reliability of target detection in complex on-vehicle environments.
Implementation Method 1
a beat signal generator configured to generate a beat signal by mixing the reception signal and the transmission signal
Data Source
AI summary
Provided is an FMCW radar device capable of reducing pairing errors. With use of a first peak frequency change rate during a first chirp period and a second peak frequency change rate during a second chirp period, a first temporary range during the first chirp period and a second temporary range during the second chirp period are calculated. When a difference between the first temporary range and the second temporary range is equal to or less than a set threshold, a first peak frequency and a second peak frequency in a current processing period are paired with each other.