Moving Object Detector Using Phase Rotation Integration
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Solution Overview
Problem
Existing moving object detection systems struggle to accurately detect whether a moving object is approaching or leaving the detection area without frequency analysis, especially when components change within the same quadrant in a two-dimensional coordinate system, leading to false detections due to noise sources.
Innovation Solution
A moving object detection system comprising an oscillator, transmitter, receiver, phase shifter, detection parts, and an angle correction mechanism that calculates a rotation angle from Doppler shift signals to determine the presence of a moving object, integrating angles to judge approach or departure, and adjusts for noise influences by setting rotation angles to zero or minimum values when noise conditions are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency analysis is performed to accurately detect moving objects, then detection precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the necessary phase information from the received signal by mixing with reference signals at specific phases (0度和90度), rather than performing complete frequency analysis. This extraction approach obtains sufficient detection data while avoiding the complexity of full spectral analysis.
Solution Approach 2:
The patent replaces complex frequency analysis mechanisms with a simpler phase comparison mechanism. By using mixers to compare phases between received signals and reference signals, the system achieves accurate moving object detection without requiring sophisticated frequency analysis hardware.
2Device complexity
If phase comparison is used to detect moving objects, then device complexity is reduced, but false detections increase due to noise
Solution Approach 1:
The patent combines the outputs from two mixers (comparing phases at 0度和90度) to calculate a rotation angle. This merging of multiple phase comparisons provides more robust detection information and helps distinguish actual moving objects from noise through the integrated angle calculation.
Solution Approach 2:
The patent transforms phase comparison results into a rotation angle in a new dimensional space. By calculating the angle from the combined outputs of multiple phase comparisons, the system creates an additional dimension for noise filtering, where true objects produce consistent angular patterns while noise does not.
3Measurement precision
If rotation angle calculation is used to determine object presence, then detection accuracy is improved, but processing time increases
Solution Approach 1:
The patent performs only the minimum necessary calculations to achieve accurate detection - specifically calculating just the rotation angle from phase comparisons. This partial action approach avoids more time-consuming operations like complete frequency spectra analysis while maintaining sufficient detection accuracy.
Solution Approach 2:
The patent uses simple trigonometric relationships to calculate rotation angles from phase differences, effectively copying the essential motion information into an angular representation. This copying method preserves detection accuracy while requiring minimal processing time compared to analyzing the complete signal spectrum.
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 detection of moving objects approaching or leaving the detection area without frequency analysis, reducing false positives from noise sources by adjusting rotation angles based on predefined thresholds and ranges, ensuring reliable object detection.
Implementation Method 1
a transmitter 11 configured to emit ultrasonic waves having the first frequency f1 to a detection area in accordance with the signal E1 from the oscillator 10; a receiver 12 configured to receive incoming ultrasonic waves from the detection area
Implementation Method 2
When at least one second frequency fin different from the first frequency f1 is obtained from the signal Ein received with the receiver 12, the first detection signal E1out becomes a first detection signal that has a frequency equal to a difference between the first frequency f1 and the at least one second frequency fin
Data Source
AI summary
A moving object detection system is provided with an existence detection part, an integrating part and an existence judgment part. Based on first and second detection signals, the existence detection part calculates a rotation angle of each transition factor that is obtained from the first and second detection signals and rotates around the origin in a two-dimensional coordinate system. The existence detection part is configured so that the rotation angle becomes less than 90 degrees. The integrating part integrates each rotation angle to obtain an integrated angle. The existence judgment part judges whether or not a moving object approaching or leaving a receiver of the device exists in a detection area based on the integrated angle and a threshold angle.