Abstract:
This report details the design, development, and implementation of an FMCW (Frequency- Modulated Continuous-Wave) ultrasonic radar system. The project’s primary objective was to create a robust and reliable sensor capable of accurate distance and, eventually, velocity mea- surement. The development process involved a synergistic co-design of hardware and software, navigating significant challenges in signal integrity and noise. Key breakthroughs include the development of a high-power transmitter using a repurposed MAX232A driver, which dramat- ically improved the signal-to-noise ratio (SNR), and the implementation of a sophisticated, adaptive ”sliding window” detection algorithm on an STM32 microcontroller. This algorithm dynamically calculates a local noise floor to reliably distinguish faint echoes, achieving a final detection range of 2.2 meters. A preliminary velocity estimation module using differentiation of distance over time has also been implemented. The final integrated system demonstrates robust object detection, overcoming initial issues of signal attenuation and environmental noise through iterative design and strategic pivots in both hardware architecture and software method- ology.
