I'm making an autopilot for a spacecraft simulator and need some advice. My craft has pairs of thrusters for pitch, yaw, and roll, and I have implemented phase plane/bang-bang controllers, one on each axis. They correctly rotate the spacecraft, including the coast phase, if used one axis at a time. It also works on all three rotational axes if the target attitude is close to the current, but if the target attitude is behind or upside down, the controllers will go into a spin and never come to a rest.

Can anyone help me modify this design so it works on all three axes simultaneously? Is it even possible? The output needs to be start-stop commands to the thrusters on the body axes.

https://youtu.be/GWXffaOTEZY?si=kS6rd6tmUkz5JErv

Sierra Space has clarified the sizes that it’s LIFE modules will come in and is looking at possibly having a LIFE module added to the Gateway Space Station as used as an initial habitat as part of the Artemis Base Camp moon base.

https://www.sierraspace.com/newsroom/press-releases/sierra-space-leads-in-the-development-of-the-first-business-ready-commercial-space-station/

https://youtu.be/Y1s0sM0WV2Q?si=SOigC7lE92yalNKa