Project

# Title Team Members TA Documents Sponsor
18 S-band Radar Altimeter
 Bobby Sommers
Elliot Rubin
Rayan Nehme
 Koushik Udayachandran design_document1.pdf
final_paper1.pdf
photo1.png
presentation1.pdf
proposal1.pdf
proposal2.pdf
video
Problem:
Currently, hobbyist RC aircraft and civil drones rely on GPS and barometers for altitude measurements. While these methods are reliable and accurate, they may not tell the operator the full story. GPS is a line of sight system and does not work when the receiver is obscured by terrain or buildings. Barometers read air pressure, but will not measure the distance between an aircraft and terrain. A radar altimeter would provide low-flying drones and RC aircraft with accurate altitude measurements relative to terrain.

Solution Overview:
Our solution relies on a FMCW (frequency modulated continuous wave) S-band radar altimeter powered off of an internal battery. The radar altimeter will be mounted to the bottom of the drone and will use the 2.4GHz ISM band in its operation.

Solution Components:

Processing Unit:
The processing unit will consist of a microcontroller, barometric altimeter, and an SD card slot. The microcontroller will calculate the range to terrain based on the doppler shift from the radar and will log this information to the SD card. It will also record the altitude measured via the barometric altimeter to compare with the radar measurement. Finally, the microcontroller will generate the control signal for the FMCW waveform.

Radar Unit:
The radar unit will consist of two submodules: the transmitter and the receiver.

The transmitter performs frequency modulation using a VCO (voltage controlled oscillator) with a tune voltage generated by the microcontroller. This tune voltage is used to sweep the VCO frequency and creates an FM waveform. A PA (power amplifier) is used to increase the transmit power and is connected to the Tx patch antenna. The Rx patch array receives the reflected signal, amplifies it through a LNA (low noise amplifier), down converts it with a mixer, and provides the demodulated signal to the processing unit.

Power Unit:
The power unit consists of a shielded switching converter to provide DC supply voltage to the other units. This DC power will be regulated by a LDO (low dropout regulator) to provide low-noise power to sensitive components such as the LNA and the VCO.

Criterion for Success:
Our radar altimeter should accurately and precisely measure distance within 1m and record measurement data to a SD card for post processing. It should have a minimum range of 20 m.

Alternatives:
There are several 24GHz radar altimeters designed for use on UAVs, but they are more expensive and are not targeted to consumers. Development boards from semiconductor companies and vendors such as Adafruit and Seed also operate in the 24GHz band, but have very limited range (<10 m).

VoxBox Robo-Drummer

Craig Bost, Nicholas Dulin, Drake Proffitt

VoxBox Robo-Drummer

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Our group proposes to create robot drummer which would respond to human voice "beatboxing" input, via conventional dynamic microphone, and translate the input into the corresponding drum hit performance. For example, if the human user issues a bass-kick voice sound, the robot will recognize it and strike the bass drum; and likewise for the hi-hat/snare and clap. Our design will minimally cover 3 different drum hit types (bass hit, snare hit, clap hit), and respond with minimal latency.

This would involve amplifying the analog signal (as dynamic mics drive fairly low gain signals), which would be sampled by a dsPIC33F DSP/MCU (or comparable chipset), and processed for trigger event recognition. This entails applying Short-Time Fourier Transform analysis to provide spectral content data to our event detection algorithm (i.e. recognizing the "control" signal from the human user). The MCU functionality of the dsPIC33F would be used for relaying the trigger commands to the actuator circuits controlling the robot.

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Beyond these minimal capabilities, we would add analog prefiltering of the input audio signal, and amplification of the drum hits, as bonus features if the development and implementation process goes better than expected.

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