Vehicle Radar Virtual Aperture Synthesis for Angle Resolution
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Solution Overview
Problem
Current automotive radar systems face challenges in distinguishing between targets that are close in angle, often reporting multiple vehicles as a single target until they are sufficiently far apart, due to limitations in physical antenna array size and resolution.
Innovation Solution
The system synthesizes a virtual aperture using vehicle movement between scans, allowing for coherent integration and improved angular resolution by generating a longer synthetic aperture, enabling the separation of targets within a few scans.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the physical antenna array size is increased to improve angle resolution, then the ability to distinguish targets in the angle dimension is improved, but the device complexity and size increase
Solution Approach 1:
The patent extends the antenna array aperture from a single plane to a three-dimensional volume by utilizing multiple radar scans taken at different vehicle positions. This creates a synthetic aperture that effectively increases the measurement baseline without adding physical antennas, resolving the contradiction between angle resolution and device complexity
Solution Approach 2:
The system creates a virtual copy of the antenna array in multiple spatial positions through synthetic aperture processing. By reconstructing the radar response as if the antenna array existed at multiple locations along the vehicle trajectory, the system achieves enhanced angle resolution without physically deploying multiple antenna arrays
2Measurement precision
If multiple scans are integrated to synthesize a virtual aperture and improve angle resolution, then the measurement precision is improved, but the processing time and complexity increase
Solution Approach 1:
The system performs preliminary processing of individual scan data to extract and store radar responses at different range bins before synthesis. This pre-processing organization enables more efficient synthetic aperture processing by avoiding redundant computations, thereby reducing the overall processing time while maintaining enhanced angle resolution
Solution Approach 2:
The patent implements a dynamic synthesis process that adaptively integrates scans based on vehicle motion characteristics and target detection requirements. By dynamically adjusting the number of scans integrated and the synthesis parameters, the system optimizes the balance between processing time and angle resolution for different operational scenarios
3Measurement precision
If the number of Tx and Rx elements is increased to provide high definition radar responses, then the measurement precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent combines the spatial diversity from multiple antenna elements with the temporal diversity from multiple scans to achieve high definition radar responses. By merging these dimensions, the system achieves enhanced resolution with a moderate number of physical Tx and Rx elements, avoiding the need for large numbers of components
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 enhances the radar system's ability to differentiate between targets in the angle dimension, providing improved accuracy and resolution, as demonstrated by the increased virtual array size and reduced ambiguity in Angle of Arrival estimation.
Implementation Method 1
at least one radar sensor disposed at the vehicle and having a field of sensing exterior of the vehicle
Implementation Method 2
to provide high definition, fine resolution in azimuth and/or elevation to determine high definition radar reflection responses for objects and surfaces detected by the system
Data Source
AI summary
A vehicular sensing system includes at least one radar sensor disposed at a vehicle and having a field of sensing exterior of the vehicle. The radar sensor includes multiple transmitting antennas and multiple receiving antennas. The at least one radar sensor is part of a suite of sensors that includes a forward viewing camera. Multiple scans of captured radar data are transferred from the at least one radar sensor to an electronic control unit. The system, via processing of transferred multiple scans of captured radar data and transferred image data, detects presence of a plurality of objects, generates a virtual antenna array with a virtual antenna aperture larger than a physical antenna aperture of the at least one radar sensor, and tracks the detected objects. The system, based at least in part on tracking detected objects, provides an output for at least one driving assist system of the vehicle.