Introduction: Air Quality Drone
Our project is to create an mobile version of an air quality sensor. We chose to further extend this project by making the sensor aerial using a drone. We also decided to use an LED strip to give us some real-time readings from the drone.
To display data collected from the drone we will also create a 3-d map of the area with a coloured coded grid dependent on air quality
1x Drone (Brush-less Motor) - at least 100 g of thrust per motor
1x Smart Citizen kit with a PM 2.5 sensor
1x Fishing Rod or String reel
1x LED Strip
1x Raspberry Pi board
1x Hot Glue Gun
1x Soldering Iron
Step 1: The Drone
We used Brush-less motors, as they have more power than other models of Drone motors. Brushless motor drones, do tend to be more expensive, as they have a camera and GPS systems.
When we were testing our drone, some of the controllers we used, were not very responsive to control. This is an important factor, when choosing your drone as a laggy controller will affect the flight.
Using 2 drones
Whilst we were prototyping we tested the idea of using 2 drones to split the weight. We tested several configurations such as side by side and on top of each other.
We found that side-by-side worked, however it was very difficult to turn and hover, even when the two drones had equal power lift and turn.
We were worried that the airflow would be disturbed when the two drones were on top of each other.
With the drone there were several challenges trying to fly the drone with the extra 90g of mass.
1.The drone wasn't powerful enough to lift up the air sensor and equipment.
When we bought the original drone, the drone wasn't powerful enough to lift the cage that we made for the sensor. To solve this problem we calculated the thrust needed to lift everything and bought a drone with enough power
2.The drone flew away
When we were testing the drone, the drone was pushed away by the wind, onto a nearby rooftop. This was quite a big setback for us, but luckily we were able to retrieve the drone. To mitigate this issue, we bought a fishing rod, as a secondary control system for the drone
3. Weight distribution
Whilst we were testing the drone, we tried attaching the cage to two different points on the drone using string. This offset the centre of mass, and pulled the drone off course, rendering it almost uncontrollable. We decided to use straws filled with skewers to support the mass.
Step 2: Coding
We used Raspberry Pi to control our Led Strip. The LED Strip we used was a 5V strip, and we had to solder the connections to the board. The code we wrote changes the colour of the LED lights, dependent on the PM 2.5 values given by the sensor. We will use a traffic light scale to grade the severity of the PM 2.5.The code we used doesn't auto run however that should be easy to integrate into the program. Although the coding took a long time to write, writing a program with 3 LEDs turning on and off would also be a easy way to colour code the readings
Step 3: 3d Modelling
We used SketchUp to create a 3-d map of the area surrounding the workshop. We took Google Maps image and outlined all the buildings, before extending the buildings upwards. We then used a tool to create a 5m^3 grid to imitate a real life 5m^3 area.
To use this map with the sensor, you need to take the reading from the sensor and input into an area in the map, which will then change colour depending on the severity of the AQI in the 5m^3 box.