Design of an onboard computer for small experimental rockets with an integrated hardware-in-the-loop validation framework
Description
Small sounding rockets provide an accessible, cost-effective platform for education and experimental research, especially at universities. In such projects, the onboard computer (OBC) is essential to mission reliability. It is responsible for sensor data acquisition, real-time flight-state detection, data logging, and actuation during recovery events. This work presents the design and implementation of a dedicated OBC for small experimental rockets, together with systematic validation using an integrated hardware-in-the-loop (HIL) simulation framework. The proposed OBC integrates an ARM-based STM32F407 microcontroller, a multi-sensor measurement suite including inertial and barometric sensors, non-volatile data storage, dual pyrotechnic channels, a robust power-management subsystem, and a fully deterministic software architecture tailored for real-time flight-event detection. Complementing the flight hardware, the HIL environment reproduces the electrical, timing, and communication behavior of onboard sensors with high fidelity. Synthetic measurements derived from flight-dynamics simulations are injected through a dedicated interface, enabling end-to-end validation of data acquisition, state-transition logic, and onboard memory logging without requiring physical launches. Experimental HIL results demonstrate reliable detection of high-energy, low-energy, and apogee flight phases under realistic conditions, validating both the hardware design and algorithmic performance. The datasets and design files released with this work provide a reproducible foundation for educational and research activities in similar avionics projects. All files required to replicate the proposed onboard computer and HIL validation framework are openly available on Mendeley Data under a CC BY-NC 4.0 license. Hardware resources include complete Altium Designer project files and bills of materials for the avionics hardware, designed according to JLCPCB manufacturing constraints. The embedded software was developed using STM32CubeIDE and STM32CubeMX (v6.12.1), based on the STM32CubeF4 and STM32CubeH5 firmware packages, written with the HAL library and documented with concise, field-validated comments. The repository also includes LabVIEW Community Edition 2022 Q3 Virtual Instruments used for HIL control, telemetry visualization, and data extraction, as well as experimental datasets obtained during HIL simulations, including real-time telemetry, onboard flash logs, and reference trajectories. Photos and videos of the onboard computer, HIL bench setup, and experimental configurations are additionally provided to support reproducibility and educational use.
Files
Institutions
- Universidade Estadual de LondrinaParaná, Londrina