Adaptive RFID Reader Interrogation Control
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Solution Overview
Problem
Passive RFID sensors face challenges in adapting to varying radio-level conditions and interference, which affects the interrogation of sensor values and the accuracy of sensed quantities, leading to issues with signal degradation and battery consumption.
Innovation Solution
A method and system that control the interrogation rate and accuracy of passive RFID sensor tags by analyzing signal-to-noise ratios and variance of received values, adjusting the interrogation rate and power based on statistical analysis to improve accuracy and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the interrogation rate is increased to improve measurement accuracy, then the reliability of sensor values is improved, but the energy consumption and interference increase
Solution Approach 1:
The interrogation rate is made dynamic rather than fixed. The system continuously monitors the quality of received sensor values and adjusts the interrogation rate in real-time based on actual signal conditions, matching the interrogation frequency to the actual needs of the sensing application.
Solution Approach 2:
The system implements feedback by monitoring the quality of received sensor values and using this information to adjust the interrogation rate. This closed-loop control ensures that the interrogation rate is optimized based on actual signal conditions, improving reliability while minimizing unnecessary energy consumption.
2Measurement precision
If the interrogation power is increased to improve signal quality, then the measurement precision is improved, but the harmful interference increases
Solution Approach 1:
The interrogation power is made dynamic and adaptive. The system monitors signal quality metrics and adjusts the transmission power in real-time, increasing power only when signal quality deteriorates and reducing power when conditions are good, thereby minimizing interference while maintaining measurement precision.
Solution Approach 2:
The system changes the power parameter dynamically based on signal conditions. By monitoring quality metrics and adjusting power levels accordingly, the system optimizes the balance between measurement precision and interference generation, using minimum necessary power to achieve required accuracy.
3Reliability
If the interrogation rate is increased to compensate for signal degradation, then the reliability is improved, but the loss of time increases
Solution Approach 1:
The system dynamically adjusts the interrogation rate based on real-time signal quality assessment. Instead of using a fixed high rate that wastes time, the system increases interrogation frequency only when signal quality deteriorates below acceptable thresholds, minimizing unnecessary time loss while maintaining reliability.
Solution Approach 2:
The system uses feedback from signal quality monitoring to control the interrogation rate. When quality metrics indicate reliable readings, the system reduces interrogation frequency to minimize time loss. When quality deteriorates, the system increases frequency to maintain reliability, creating an efficient adaptive response.
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 enhances the accuracy of sensed quantities by dynamically adjusting the interrogation rate and power, improving the reliability and efficiency of passive RFID sensor systems in varying radio conditions.
Implementation Method 1
Passive RFID tags utilize the modulated backscattering communication principle... the RFID tag antenna receives power and RF signals from the RFID reader and provides them to the chip. The chip processes the signals and sends the requested data back to the RFID reader. The backscattered signal is modulated according to the transmitted data.
Data Source
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AI summary
In a system having a radio frequency identification (RFID) reader and at least one passive RFID sensor tag, the RFID reader sends a radio frequency interrogation signal from to the passive RFID sensor tag having a sensor that provides a sensor value. The RFID reader receives from the passive RFID tag a backscattered radio frequency signal carrying the sensor value. An interrogation rate of the sensor tag, an accuracy of interrogation and/or a power of the radio frequency interrogation signal transmitted to the sensor tag is controlled based on a statistical analysis of the multiple received sensor values, multiple interrogations and/or a signal-to-noise ratio (60-69).