Radar Signal Processing for Overhead Object Collision Detection
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Solution Overview
Problem
Conventional in-vehicle radars have low accuracy in angle measurement, leading to erroneous detection of upper structures as objects on the roadway, and struggle with determining object height due to the need for approaching the first null point in the antenna directivity pattern, especially when multiple objects overlap, resulting in deteriorated estimation accuracy.
Innovation Solution
A radar signal processing device incorporating a Fourier transform unit, peak detection unit, azimuth detection unit, object position determining unit, and collision determining unit to accurately and promptly assess collision risks by analyzing signal intensity, azimuth, and Doppler velocity components, determining collision based on reference values or distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the radar device waits for the first null point to be generated in the antenna directivity pattern to determine object height, then the height estimation accuracy is improved, but the time required for collision determination increases significantly
Solution Approach 1:
The patent pre-calculates and stores correspondence relationships between vehicle traveling velocities, relative distances to objects, and Doppler velocity components in a storage unit before actual collision determination occurs. This preliminary preparation allows the system to immediately query pre-computed data during real-time operation, eliminating the need to wait for null point generation while maintaining accurate height estimation capabilities
Solution Approach 2:
The patent creates a computational model that copies the physical relationship between vehicle motion and Doppler velocity changes. By storing the correspondence relationship between traveling velocity, relative distance, and Doppler velocity component variations in a lookup table, the system replicates the complex physical calculations in advance, enabling rapid query-based determination without real-time computation delays
2Device complexity
If the radar device uses simulation with the assumption of one object to determine the first null point, then the determination process is simplified, but the estimation accuracy deteriorates when multiple objects are present with overlapping signal waveforms
Solution Approach 1:
The patent changes the fundamental parameter used for collision determination from spatial position (null point location in antenna directivity pattern) to Doppler velocity component variation. This parameter transformation allows the system to determine object height and collision risk based on velocity-based measurements that are not affected by signal waveform overlapping from multiple objects, thereby maintaining accuracy in complex environments without requiring complex signal separation procedures
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 accurate and timely collision determination between a vehicle and objects above, improving detection accuracy and reducing the time required for determining object presence and height, even in environments with overlapping signal waveforms.
Implementation Method 1
The Fourier transform unit generates an FR map in which the relative distance and the relative velocity between a vehicle and an object are associated with the signal intensity level of a reception signal by performing Fourier transform on a reception signal
Implementation Method 2
The first collision determining unit determines whether the vehicle collides with the object... on the basis of data indicating a correspondence relationship between a traveling velocity of the vehicle and a relative distance between the vehicle and the object... at the time when an amount of variation in a Doppler velocity component of the vehicle with respect to the object
Data Source
AI summary
A collision determining unit (404) determines whether a vehicle (1000) collides with an object (1001) when a Doppler velocity component between the vehicle (1000) and the object (1001) varies to a first reference value, or when the vehicle (1000) has traveled to a range R corresponding to the first reference value.