Wireless Tag Reader Direction Detection Using RSSI and Read Frequency
Solution Overview
Problem
Existing wireless tag reading technologies struggle to accurately determine the moving direction and existence area of wireless tags passing through a passage, relying solely on communication times and signal strength without considering the received signal strength indicator (RSSI) effectively.
Innovation Solution
A wireless tag reading device equipped with multiple antennas along a passage, a number-of-times acquisition unit, a strength acquisition unit, and a direction specifying unit, which acquires and analyzes the number of readings and RSSI for each antenna to accurately determine the moving direction and existence area of wireless tags by comparing RSSI averages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If only communication times and signal strength are used to determine moving direction, then the system is simple, but the measurement precision is insufficient
Solution Approach 1:
The patent changes the parameter used for direction determination from simple communication count to a composite parameter that includes RSSI (Received Signal Strength Indicator) values. By incorporating signal strength measurements into the direction determination algorithm, the system achieves higher measurement precision without requiring additional hardware complexity
Solution Approach 2:
The patent introduces RSSI as an intermediary parameter that bridges the gap between simple communication counting and complex signal analysis. The RSSI values serve as a mediator that provides additional information about signal quality and distance, enabling more accurate direction determination while maintaining system simplicity
2Area of stationary object
If multiple antennas are arranged along the passage, then the area coverage is improved, but the device complexity increases
Solution Approach 1:
Each antenna in the array serves multiple functions: it acts as a transmission/reception element, a direction reference point, and a signal strength measurement device. By making each antenna multi-functional, the system achieves comprehensive passage coverage without proportionally increasing overall system complexity
Solution Approach 2:
The passage monitoring function is segmented across multiple antennas, with each antenna responsible for a specific spatial sector. This segmentation allows the system to cover the entire passage area while maintaining manageable complexity through modular antenna units that can be independently configured and calibrated
3Measurement precision
If RSSI analysis is integrated with reading frequency data, then the measurement precision is improved, but the use of energy increases
Solution Approach 1:
The system performs RSSI analysis only when necessary for direction determination, rather than continuously monitoring all signal parameters. By applying partial action - analyzing RSSI data selectively based on communication events - the system achieves improved measurement precision while avoiding excessive energy consumption from continuous full-spectrum signal analysis
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 solution enables precise tracking of wireless tag movement direction and area specification, improving accuracy compared to conventional methods by integrating RSSI analysis with reading frequency data.
Implementation Method 1
a plurality of antennas 11 and 21 for wireless tag communication
Data Source
AI summary
In one embodiment, a wireless tag reading device includes a plurality of antennas for wireless tag communication, a number-of-times acquisition unit, a strength acquisition unit, and a direction specifying unit. Each antenna is arranged along a passage through which a wireless tag passes. The number-of-times acquisition unit acquires a number of times of reading of data of the wireless tag read by each of the antennas for each unit time for each of the antennas. The strength acquisition unit acquires a received signal strength indicator when the data of the wireless tag is read by each of the antennas for each unit time for each of the antennas. The direction specifying unit specifies a moving direction of the wireless tag passing through the passage based on the number of times of reading and the received signal strength indicator for each of the antennas that are acquired for each unit time.