UWB Motion Detection Template Correlation
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Solution Overview
Problem
Existing motion detection devices, particularly those using Doppler radar and UWB receivers, face limitations in range resolution and reliability, especially in close-range applications and for presence or access detection, making them unsuitable for building installations and precise movement tracking.
Innovation Solution
A method utilizing a UWB signal with a transmission template that is a mixture of a Gaussian pulse and an angle function, which is resistant to signal changes during transmission, reflection, and reception, allowing for precise detection by correlating the received signal with a predistorted reception template, and using multiple correlation elements with phase shifts to enhance detection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Doppler radar is used for motion detection, then detection capability for moving objects is improved, but detection reliability for presence sensing in close-range applications deteriorates
Solution Approach 1:
The patent changes the fundamental operating parameters by using UWB (Ultra-Wideband) signals instead of traditional Doppler radar frequencies. This enables both high detection reliability and fine range resolution (down to 10 cm) by utilizing impulse radio technology with very short pulse durations in the nanosecond range, resolving the contradiction between reliable presence detection and precise distance measurement.
Solution Approach 2:
The patent replaces the Doppler effect-based mechanical detection system with a correlation-based signal processing system. Instead of measuring frequency shifts from moving objects, the system uses matched filtering and correlation techniques to detect both stationary and moving objects with high precision, achieving reliable presence sensing and accurate range measurement simultaneously.
2Measurement precision
If pulse duration is shortened to improve range resolution, then measurement precision is improved, but RF overhead increases
Solution Approach 1:
The patent employs periodic transmission of very short UWB pulses with duty cycles optimized to minimize RF overhead. By using impulse radio with pulse durations in the nanosecond range and appropriate pulse repetition intervals, the system achieves fine range resolution while maintaining low average power consumption and complying with regulatory limits on RF exposure.
3Measurement precision
If conventional UWB receiver with power detection is used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent introduces correlation elements as intermediary processing stages between the simple power detector and the final detection logic. These correlation elements perform matched filtering by comparing received signals with stored transmission templates, significantly improving detection precision and range resolution while adding manageable complexity through efficient digital signal processing techniques.
4Adaptability or versatility
If Doppler radar is used for motion detection, then detection capability for moving objects is improved, but adaptability for presence detection and building installations deteriorates
Solution Approach 1:
The patent creates a universal detection system based on UWB impulse radio that can perform multiple functions including presence detection, motion detection, and ranging. The correlation-based processing architecture allows the same hardware to reliably detect both stationary objects (for presence sensing) and moving objects (for motion detection), making it adaptable to various building installation applications with a single device.
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 provides high detection reliability and range resolution, enabling effective motion detection and presence sensing in close-range applications, suitable for building installations, with improved correlation between the received and transmission signals, even in the presence of interference.
Implementation Method 1
receiving a signal reflected by an object located in the detection range as a received signal
Implementation Method 2
the time offset corresponds to the signal propagation time expected at a specified distance from the object located in the detection range
Data Source
Figure 1
Figure 2~3
Figure 4a~4c
AI summary
The method involves transmitting a ultra wide band signal as transmit template, and receiving a reflected light from detection range object signal. The received detection range object signal is evaluated based on distance with respect to the sensor (1) and correlated with receiving template to carry out correlation offset. The location of object (11) is judged based on reflected transmit template and correspondence of received template with transmitted template. The transmit template is generated based on Gaussian pulse envelope time domain weighted angle function.