Radar Detection System for Stationary Target Permanence
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Solution Overview
Problem
In industrial safety applications, radar systems may incorrectly treat a person entering a monitored area as background if they remain still for a sufficient time, leading to hazardous machinery being reactivated in the presence of people, as existing technologies fail to effectively distinguish between stationary objects and stationary individuals.
Innovation Solution
A radar detection system that automatically alternates between two target recognition modes: a first mode for detecting entering targets and a second, more sensitive mode for monitoring their permanence, ensuring the area is not cleared until stable movements are detected, thereby preventing false deactivation of hazard alerts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the background profile is constantly updated to learn variations in stationary scenario, then the radar can accurately identify stationary objects, but a person entering the monitored area and remaining still will be incorrectly treated as background
Solution Approach 1:
The patent implements dynamic switching between two operational modes: a first mode for detecting entering targets and a second mode for monitoring permanence of detected targets. This dynamic adaptation allows the system to adjust its detection sensitivity based on the operational phase, preventing stationary persons from being incorrectly classified as background while maintaining accurate stationary object identification.
Solution Approach 2:
The system periodically alternates between the first detection mode and the second monitoring mode. During the first mode, the background profile is updated to learn stationary scenarios. During the second mode, the system monitors for movements indicating target permanence. This periodic action ensures that persons who stop moving are not immediately discarded as background, thereby maintaining safety reliability.
2Device complexity
If the radar uses a single detection mode with continuous background updating, then the system operation is simple, but the radar may stop signaling hazardous conditions when the area has not been evacuated
Solution Approach 1:
The detection system is segmented into two distinct operational modes: a first mode for initial target detection and background learning, and a second mode for monitoring target permanence through movement detection. This segmentation allows each mode to be optimized for its specific function while working together to solve the contradiction between system simplicity and safety reliability.
3Measurement precision
If the radar waits for a certain number of cycles to complete Fourier transform before determining target presence, then the detection is more accurate, but the target detection is delayed
Solution Approach 1:
The system performs preliminary detection in the first mode to identify potential targets and trigger the second mode. This preliminary action allows the system to begin monitoring a specific region of interest before completing the full Fourier transform analysis, thereby reducing detection delay while maintaining accuracy through the subsequent monitoring phase.
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 reduces the risk of hazardous machinery being reactivated by ensuring that stationary individuals are accurately detected and the area is not mistakenly cleared, enhancing safety by maintaining alertness until all targets have vacated the monitored area.
Implementation Method 1
Radar detection can detect objects in an environment by transmitting radar signals in a given field of view, and then receiving and analyzing the signal reflected from the objects
Implementation Method 2
The reflected signal is collected by the same transceiver designed for transmission, which detects a constant frequency difference between the transmitted signal and the received signal, due to the time delay required for the signal to reach the target and return to the transceiver
Implementation Method 3
Fourier analysis, applied on a mix of the transmitted signal and the received signal, e.g. a product thereof, can accurately identify this frequency difference, by assigning a distance from the transceiver to each harmonic component of the signal
Data Source
AI summary
A method and a system for radar detection system include, after cyclically generating a detection profile representing signal intensity as a function of position, cyclically analyzing the detection profile by alternating two modes of analysis. The first mode is suitable to detect a target entering the field of view, but may have poor sensitivity to targets that move at a low speed for a long time, such as a person entering a hazardous area and stopping. When this mode detects a target, a second mode is entered, which is more sensitive and suitable to detect the permanence of the target in the field of view, and in particular small movements connected to the vital signs of the target. The second mode may be based, for example, on complex signal deviations for each position with respect to a long-term complex mean value for that position. Only if the second mode does not detect any target for a certain restart time, the field of view is deemed to be clear and the first mode is used again.