PSAS RCS Capstone Final Presentation Team: Brian Breniser - Chris Liebert - Paul Lee - Harrison Bailey - Cort Alexander - Sohail Nayani - Tyler Alway Sponsor: Jamey Sharp and Theo Bailey from PSAS
Tasks and Team Roles Person Planned Role Actual Role Brian Breniser Lead & embedded architect Lead & Unit tester & prototype tester Chris Liebert Scheduler & test library architect Scheduler & test library architect Paul Lee Requirements guru & telemetry data architect Requirements guru & telemetry data architect & prototype tester Harrison Bailey DevOps / backup engineer & main logic architect DevOps / Backup engineer & main logic architect Cort Alexander Backup lead & control module architect Backup lead & control module architect Sohail Nayani JSBSim specialist & test library architect JSBSim specialist / test mode Tyler Alway Risk management & sensor module architect Risk management & sensor module architect & prototype tester
The Project Step 1: Build a Flight controller, starting with roll control: Software used to control and monitor the aircraft Keeps the rocket stable in flight and provide roll control Step 2: Make it testable Use JSBSim to test the physics of a rocket Plug it into the flight controller
The Project Why is this required? Transferring from fin based controller to cold gas jet based controller, allowing aircraft to be controlled in thin atmosphere Want to improve testability for existing design https://www.youtube.com/watch?v=yup2_m3gpim&ab_channel=psas https://www.youtube.com/watch?v=dbslpdyd2ec&ab_channel=psas
The Language What is Rust? New open-source language sponsored by Mozilla Strongly statically typed, compiled, cross-platform language Advantages Memory safe WITHOUT garbage collection Move semantics Comparable speeds to C, C++ LLVM backend which allows for powerful optimization Gotchas New and changing language Library support exists but is not refined
Build Process Travis CI / Github - Continuous Integration Automatically try to build and run tests Provides EMail and Github notifications CMake / Cargo Build Integration Generates build configuration / Makefile Used cmake-rs to launch CMake from Cargo
Assumptions, Constraints, and References Assumptions: Flight controller runs on Linux with hardware, but we should compile/test without hardware Constraints Written in Rust, tested using JSBSim Compiled with 32 bit architecture References Prior PSAS work JSBSim documentation
Product Features Promised vs Delivered Promised Receive sensor data Determine response and send control signals Written in Rust - Linux compatible and 32 bit Modular to add and remove hardware Flight mode and Test mode compile separately Utilize JSBSim for physics simulation Simulate sensors and actuators in JSBSim Runs on LED prototype Run on Satellite reaction wheel Delivered Yes Yes Yes Yes Yes Yes Yes No
Deliverables Source code In a repository on Github, all open source using GPL2 license PSAS group will fork the Github repository into their own project directory Flight Controller Common components I2C and GPIO integration software Test framework JSBSim framework and glue code between Rust and C++
Demo https://www.youtube.com/playlist?list=pl8ukbdawzpifd2dj1vvfjewf5f92efrez
Process and Schedule The best laid plans of mice and men Planned Process Actual Process Planned Schedule Actual Schedule Feature driven development Pull request for changes Manual testing for each pull request Module driven development Pull request + occasional one off commits to master Integrated Travis CI for automated testing 3 iteration plan for implementation Baseline work Testing Stretch goals Extra development effort to learn hardware Refined behavior on the prototype No time left for stretch goals
Problems and Contingencies Event Mitigation Didn t expect compiling to 32 bit Didn t meet iteration schedule Running on cold gas jet prototype was problematic JSBSim was a blocker the whole time Used built in rust methods to cross-compile Dropped stretch goals but finished core work Ran on LED board instead, then borrowed the LED board from PSAS so we could test anytime we needed, it was also safer to test repeatedly on the LED board Rearranged so more people worked on the testing team
Lessons Learned Co-location or active online communication is helpful for good development Rust is still new and changing (we went through 3 version in this project) Some libraries are not cross platform Flight controllers are awesome, but complicated JSBSim is awesome, but complicated and has lackluster documentation Git is your frenemy Continuous Integration is your friend You can compile C++ inside of Rust using cmake + Cargo We learned how to use C++ libraries in Rust using a C ABI The more prototyping, the better
Questions?