Gantry-Driven HF RFID Product Location Identification System

Last crawled date: 1 year, 11 months ago

Gantry-Driven HF RFID Product Location system is the end product of my FYP as Mechatronic Engineering Student. Although it is not physically proved to be functional as a production location identification system, but through simulation and minimum level proof of theory, I obtained an above 90% accuracy through my methodology used in this prototype.

The objective of this prototype is to find an alternative method in product location identification when UHF RFID system is too hard to obtain and the reader itself is too expensive for the application.

Working Theory: -
1. The HF RFID Reader will be scannning through the movable area of the gantry mechanism.

2. The RFID Reader will returned the read data from the tag once tag is detected. At the same time, the step counter will calculate the current step counts of the stepper motor steps for both xy axis gantry movement.

3. The xy axis step counts and also the return datas from the tag is colllected and output into .csv file.

4. The CSV file will be processed to obtain the centroid coordinate of the RFID tag.

Methodology to obtain centroid coordinate of tag similary the product's location is by averaging of x and y data points return to the .csv file.

Pros:
1. Price Effective for RFID System
- Cheaper Price compare to the UHF RFID system

2. Non Complex System
- Easy Calculation to get tag location compared to UHF RFID System that used trionometry method and signal strength for getting the location.

3. Direct Product Location Identification
- The methodology used is straight forward and most importantly accuracy is preserved up to few mm scale if the interval for each horizontal iteration decreased.

Cons:
1. Mechanical Motion
- Energy loss in friction and Material Fatigue

2. Tag Collision
- When tags are closed to each other, the detection rate of the tag will reduce by half. It means with single tag, I can totally get 250 data points for my location. However, when tags are closed to each other, the tag of interest may only have 100 data points due to the interference between electromagnetic wave. Reducing in data points can effect the product location identification algorithm that adapting the averaging method of data points.

3. Non real-time Product Location Identification System
- The system must store the output by a single system and output it to .csv file or equivalent. After completed the scanning, it will only enter data processing stage. But, UHF RFID system can achieved the real time Product Location Identification.

4. Time consuming
- Time is consumed in the scaning. But, the time can be reduced by adding more RFID tag to the system. However, additional controller is needed.

5. XY axis location identification
- Only able to achieve plannar product detection. Meanwhile, UHF RFID system could perform 3 axis location identification by additional of receiving antenna and reader.

6. Bounded Area of Detection
- Bounded by gantry mechanism size.
- Bounded by read range of the RFID Reader.