Radar Module Vibration for Azimuth Estimation Accuracy
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Solution Overview
Problem
Radar devices struggle to accurately estimate the azimuth of stationary targets located at similar distances due to insufficient removal of cross-correlation components between reception signals, which are constant and difficult to distinguish.
Innovation Solution
A radar device with a vibration applying structure that introduces irregular vibrations smaller than the radar range resolution, causing the absolute phases of targets to change randomly, allowing the cross-correlation component to be averaged out and enabling accurate azimuth measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If array extension is implemented using the Khatri-Rao product to generate an extended correlation matrix, then the number of reception antennas is virtually increased, but cross-correlation components between reception signals remain and cannot be sufficiently removed, making it difficult to accurately estimate the azimuth of stationary targets at similar distances
Solution Approach 1:
The patent applies mechanical vibration to the radar module by introducing a vibration applying structure that vibrates the radar module in a direction orthogonal to the propagation direction of the radar wave. This vibration causes the phase of the received signal to fluctuate randomly, which transforms the constant cross-correlation component into a time-varying component that can be removed through time averaging, thereby resolving the contradiction between increasing antenna elements and eliminating cross-correlation interference
Solution Approach 2:
The patent changes the physical state of the radar module by introducing vibration, which dynamically alters the phase parameter of the received signal. This parameter change converts the static cross-correlation problem into a dynamic one that can be solved through statistical processing, enabling accurate azimuth estimation while maintaining the benefits of array extension
2Measurement precision
If spatial smoothing is performed on the extended correlation matrix, then some correlation reduction is achieved, but the cross-correlation component between reception signals cannot be completely removed, still preventing accurate target identification
Solution Approach 1:
The vibration applying structure introduces random phase fluctuations that convert the constant cross-correlation component into a time-varying component. When multiple reception signals are averaged over time, the time-varying cross-correlation components cancel each other out, completely removing the harmful constant cross-correlation that spatial smoothing alone could not eliminate
Solution Approach 2:
The patent extracts and removes the cross-correlation component from the reception signals by using vibration-induced phase fluctuations. The time-varying cross-correlation components are separated from the useful signal through their statistical properties and removed via averaging, leaving only the clean signal components for accurate target identification
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
The radar device effectively identifies and measures the azimuth of stationary targets with high accuracy by canceling out cross-correlation components between reception signals, improving angle estimation precision.
Implementation Method 1
a vibration applying structure that irregularly applies, to the radar module, vibration with a magnitude smaller than the radar range resolution
Data Source
AI summary
A radar device that includes a radar module and a vibrator. An example of the vibrator is an actuator, which generates vibration with a magnitude smaller than the range resolution of the radar device. A shield case is supported on a bracket with a fixing portion interposed therebetween. The fixing portion is made of an elastic material. As the actuator vibrates, the shield case vibrates irregularly, and the vibration of the shield case is transmitted to a circuit board. On the front side of the circuit board, a pattern constituting an array antenna is formed.