Radar Motion Detection With Time-Domain Screening for Low Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radar devices in human machine interfaces face challenges in achieving low power consumption while maintaining immediate responsiveness to gestures or movements, particularly in portable consumer devices where battery life is a critical concern.
Innovation Solution
Implementing time-domain processing to detect motion using radar signals, activating frequency-domain processing only when motion is detected, thereby reducing power consumption by keeping frequency-domain processing circuitry in a low-power mode during idle times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the radar device performs continuous frequency-domain processing to detect gestures and movements, then the responsiveness and detection accuracy are improved, but the power consumption increases significantly
Solution Approach 1:
The processing system is divided into two independent parts: time-domain processing circuitry that continuously monitors radar signals for motion, and frequency-domain processing circuitry that performs detailed gesture analysis. This segmentation allows the system to activate the power-intensive frequency-domain processing only when motion is detected, rather than running it continuously.
Solution Approach 2:
The system uses periodic scanning where the radar device alternates between idle/sleep periods with low power consumption and scan periods where it actively monitors for motion. During idle periods, only the low-power time-domain processing remains active, while during scan periods, frequency-domain processing is activated when needed.
2Loss of time
If the radar device remains fully active to detect motion immediately, then the detection speed is improved, but the battery life decreases
Solution Approach 1:
The time-domain processing circuitry continuously performs preliminary motion detection in the time domain before activating the more complex frequency-domain processing. This preliminary action allows the system to maintain a low-power state while still being ready to quickly detect and respond to motion events when they occur.
3Measurement precision
If the microcontroller is kept active for presence detection, then the presence detection accuracy is improved, but the overall power consumption increases
Solution Approach 1:
The time-domain processing circuitry acts as an intermediary between the radar signal reception and the microcontroller. It filters and pre-processes the signals, only activating the microcontroller when actual motion is detected. This intermediary layer prevents the microcontroller from being unnecessarily activated during periods when no motion is present, thereby reducing its power consumption while maintaining detection accuracy.
Data Source
AI summary
In an embodiment, a method includes receiving radar signals and detecting motion based on time-domain processing of the received radar signals. In a further embodiment, a radar device includes a receive circuit configured to receive radar signals; and a time-domain processing circuit configured to detect motion based on time-domain processing of the received radar signals.