Purpose and Context

The purpose of this project is to design and implement a launch and flight control system to expand the capabilities of Oregon State's Hybrid Rocket team. A hybrid rocket uses both a solid fuel and liquid oxidizer allowing for a safer and more controlled motor burn. This presents a number of challenges not found on other university rocketry teams such as pre-flight remote oxidizer filling, ignition timing with oxidizer injection, mid-flight oxidizer flow control, and real-time video monitoring. It is for these reasons that we aim to create a safe, reliable, and expandable launch and flight control platform with robust hardware and software components that can be used by Hybrid teams for years to come.

Our Client

Our client is the sponsor of the Hybrid Rocket team, Dr. Nancy Squires of the MIME department at Oregon State.

Website Details

This website contains the following information:

• Project Timeline
• Team Members and Roles
• Engineering Requirements
• Project Artifacts
• Block Progress Tracking

Our project can be divided into multiple Phases:

Throughout the last three terms we have created both a system for subscale testing and full-scale testing/launching for the Hybrid rocket team. Our subscale system helped the Hybrid team perform many successful fuel grain tests throughout the first two terms of the project. This system, named the T3st Core, was centered around a Raspberry Pi coded with python. It provided precise pressure data collection, robust controls, and filming of the subscales tests. On the logic side, we wrote controls to handle over pressurization, pressure timeouts, failed ignitions, and more. We created electrical fail-safes for software-less shut-off of the oxidizer valve to halt a test. These included a limit switch to detect the test stand failing over and a trip wire to detect the motor leaving the stand. On multiple occasions these systems averted potentially dangerous events from damaging the motor and testing equipment.

In our Final Design, named the Warp Core, we replaced many of the purchased modules with custom designed systems. This included replacing the Raspberry Pi that had used in the T3st Core with custom made microcontroller and FPGA PCBs. We also created custom power and I/O breakout PCBs as well as a custom GUI for the system. The power PCB provided steady 3.3V and 5V power from our 24V power supply for use in the FPGA and Microcontroller respectively. The I/O board translated the 3.3V signals from the FPGA into the proper voltages for each of our connected peripherals, opto-isolation of logic signal from power signal, and ground isolation from AC signals. The Microcontroller housed all of our control logic leading up to launch. It sent commands to the Rocket’s on-board electronics and the FPFA via RS232 and SPI respectively, provided logging to an SD card, and connected to the GUI via an ethernet off-load chip. To manage all these diverse task, a Real-time operating system written in C was implemented. The FPGA allowed for expanded I/O control and increased safety of operation. The FPGA provided a software independent method for bringing the launch system to a safe state in the case of microcontroller failure. It also provided precise controls for each of the system’s subsystems such as the rocket’s fill arm, providing the microcontroller a layer of abstraction in its controls. The GUI provided a visual representation of the rocket’s systems in the form of an animated P&ID of the rocket, real time graphs, and numerical displays. The GUI also provided simply buttons to initiate set sequences of operations (such as connect fill arm) as well as a console for more specific commands. The P&ID had pop-up windows for every valve and sensor to allow more detailed information as well as control overrides to each element.

Together, our systems provided an easy to control and robust system that will, when conditions allow the continuation of the rocket program, enable the hybrid rocket team to reach new heights. We thank the Hybrid Rocket team and Dr. Squires for providing this opportunity exercise our engineering knowledge and learn new skills.