We want active stabilization for LV3, but wish to escape the vexxing dynamic pressure limitations of the present aerodyamic canard based roll-control system used on LV2.3.
The concept:
- Cold-gas rocket propulsion
- 8 N thrust (roll), 11 N (pitch x, y)
- Nitrogen tank at 4500 psi
- 8x 3D-printed bell nozzles
- PWM throttling
- "Robust control"
Rao bells (e.g. nearly ideal nozzles) are hard to machine c.f. conical nozzles, but easy to 3D print. This also enables “plug & play” optimal expansion ratios for any trajectory. Here is the basic workflow:
- Determine flight envelope from simulation (for instance, using OpenRocket)
- Run
nozzle_sizing.mscript to determine nozzle design parameters - Plug expansion ratio into parametric solid model and export
.stl - Print nozzles, install in carrier ring
- ???
- Fly!
This repo includes mathematical models, matlab and python controller scripts, eagle files for a custom MOSFET relay board, solenoid PWD test data for transfer functions, system test data and bode analysis, and the Solidworks CAD assembly for the LV3 Reaction Control System.