IRIS National Fair Finalist and Building an Autonomous Rover!
Around 3 months back, I had applied as a participant for the highly selective IRIS National Fair/Competition, and was selected as a finalist for the fair around a week back. For the competition, I built an autonomous rover that could detect gas leakages and potential fires/ flame leakages in factory pipelines and industrial areas.
Below contains the report synopsis of the project I created, along with a few pictures of the rover itself.
Purpose
Built a DC motor driven rover vehicle with obstacle avoidance and line following modes, to sense hazardous gases/flame and upload sensor values tagged with GPS data in real time to internet for monitoring tools to consume.
Reason
Unmanned rover has possible use in refineries, chemical plants, docks, warehouses to monitor & report on gas/flame levels beyond set thresholds. Can also function as IOT station if payload module is standalone.
Functionality
Rover designed to autonomously navigate unknown areas using random walk based on ultrasonic distance measuring, and also known marked black tape paths using line following modes. Offloads human operator from task of monitoring flames, LPG, alcohol, methane, smoke etc levels, and able to report live to internet over 4G, with data as GPS location tagged — upload periodic logs to google drive and threshold warnings to Pubnub server for client monitoring tools to trigger alerts.
Hardware and Software
Raspberry Pi4, Arduino Mega, power bank, AA batteries, distance, line tracking and gas sensors, servo motor, DC motors, plastic chassis, 4G USB dongle and GPS antenna.
Python scripts to control distance measuring/line tracking, wheel motors, data logging, alert triggering and reading gas data from Arduino. Arduino program (sketch) to read gas sensors.
Procedures used to test
Payload
1) Gas sensors — tested with small samples of LPG, smoke, fire, alcohol for sensitivity, wind effect and range. MQ2/3/9 family of devices.
Mobility
1) Ultrasonic sensor and Servo motor — Swivelling; cone and range of obstacle detection;
2) Line tracking sensors — follow non-reflective black tape on floor turning at various curved angles;
3) Motors — extended runs; tiles of varying roughness; paved road surface.
Data logging and communication
1) GPS antenna — outdoor run on own motors and rover carried in a car. Verified GPS NMEA data using visualiser to get track path on Google Maps.
2) 4G SIM — uploading of data file to google drive; gas threshold warning to PubNub publish-subscribe server for client monitoring tools to trigger on.
3) 32GB microSD card on USB port for data logging.
Results
1) Sensitivity of gas sensors to many of target gases/flame proven and reviewed using reference device data sheets
2) Set of programs built (Python and Arduino sketches) for each function — motor controller, ultrasonic sensor, servo motor, line sensors, gas sensors, GPS, 4G internet.
3) Accurate positional data to a few feet obtained outdoors and uploaded to cloud.
Conclusion
Built extendable gas detector on autonomous rover.
Can form the basis of more powerful rovers and IOT stations for industrial and mining applications.
Reduce human risk in hazardous conditions, like tunnels
Scope for improvements
Mobility is bit weak due to low power:weight ratio
Ultrasonic sensor fails on rougher surfaces due to scattering.
Motor control algorithm could be better tuned
Rear distance sensor
The IRIS National Fair will be held some time during December of 2021, so as of now, I am preparing the materials and everything else that would be required for the final presentation. After the finalist stage, around 20 or so winners are picked, which receive the Grand Prize Award. From those 20, around 3 are chosen to represent Team India in the National ISEF competition. To read further about the IRIS competition, follow the link below.
