The RIT Launch Initiative Liquids team is developing a liquid propelled rocket inspired by designs such as HalfCat Rocketry's Mojave Sphinx. I am currently working with the Controls & Sensors sub-team and having recently had our second critical design review last semester, we have moved into the manufacture and test fire phase. This is an ongoing project and will be updated at least every semester with progress reports.
CAD
One of my first tasks as a member of the Controls sub-team was to take measurements of the existing ground-station control box and build a model of it in Autodesk Fusion 360 to test-fit components proposed in the new design and to easier facilitate custom parts to integrate them into the control box like 3d printed panels and brackets. Per my original direction (with very limited CAD experience as an EE student) I began my first iteration and soon-after scrapped that iteration as it became wildly under-constrained. With some new knowledge on sustainably designing CAD models I began my second iteration of the slightly off-brand Pelican case which I have named Snow Goose because bird. Below are some renders of my dimensionally-accurate ground-station control box with a fully articulated hinge allowing the top to be opened and a handle that does not intersect or collide with the case body.
Ground station control software
My next major task involved implementing the full control system code for the ground-station. Several different phases would need to allow or dis-allow control of certain actuators during the pre-launch procedure and safety had the greatest importance during this process. The control flow needed to be robust and fail safely even with unforseen circumstances or loss of connection.
The control system involves the ground-station control box with all associated inputs and processing onboard. Signals would be sent over ethernet from the safe-zone 250 feet to the ground-station where they would be recieved by the launch controller and procesed. Commands to advance phase would enable or disable outputs as needed, and both the enable flag and a valid command for that actuator would need to be recieved for the launch controller to allow an output.
This system has been bench tested but not yet tested on-site. Cold flow tests and hot-fire and planned for the upcoming fall and spring semesters as remaining parts are manufactured and test plans approved by EHS.
