It was around Christmas 2012 that I started investigating an RPi drone, and the first post was at the end of January ’13.
5 years later, phase ‘one’ is all but done, barring all but the first as minor, mostly optional extras:
- Track down the GPS tracking instability – best guess is reduced LiPo power as the flight progress in near zero temperature conditions.
- Get Zoe working again – she’s been unused for a while – and perhaps, if possible, add GPS support although this may not be possible because she’s just a single CPU Pi0W
- Fuse the magnometer / gyrometer 3D readings to long term angle stability, particular yaw which has no backup long term sensor beyond the gyro.
- Add a level of yaw control such that ‘H’ always points the way she’s flying – currently she always points in the same direction she took off at. I’ve tried this several times, and it’s always had a problem I couldn’t solve. Third time lucky.
- Upgrade the operating systems to Raspbian Stretch with corresponding requirements for the I2C fix and network WAP / udhcpd / dnsmasq which currently means the OS is stuck with Jessie from the end of February 2017.
- Upgrade camera + lidar 10Hz sampling versus camera 320² pixels versus IMU 500Hz sampling to 20Hz, 480² pixels, 1kHz respectively. However, every previous attempt to update one leads to the scheduling no longer able to process the others – I suspect I’ll need to wait for the Raspberry Pi B 4 or 5 for the increased performance.
Looking into the future…
- Implement (ironically named) SLAM object mapping and avoidance with Sweep, ultimately aimed at maze nativation – just two problems here: no mazes wide enough for ‘H’ clearance, and the AI required to remember and react to explore only unexplored areas in the search for the center.
- Fuse GPS latitude, longitude and altitude / down-facing LiDAR + video / ΣΣ acceleration δt δt fusion for vertical + horizontal distance – this requires further connections between the various processes such that GPS talks to motion process which does the fusion. It enables higher altitude flights where the LiDAR / Video can’t ‘see’ the ground – there are subtleties here swapping between GPS and Video / LiDAR depending whose working best at a given height above the ground based on an some fuzzy logic.
- Use down-facing camera for height and yaw as well as lateral motion – this is more a proof of concept, restrained by the need for much higher resolution videos which current aren’t possible with the RPi B3.
- Find a cold-fusion nuclear battery bank for flight from the Cotswolds, UK to Paris, France landing in Madrid, Spain or Barcelona, Catalonia!
These future aspirations are dreams unlike to become reality either to power supply, CPU performance or WiFi reach. Although a solution to the WiFi range may be solvable now, the other need future technology, at least one of which my not be available within my lifetime :-).
Wishing you all a happy New Year and a great 2018!