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Sonar on Chip

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PROJECT DESCRIPTION AND DESIGN GOALS 

The project is oriented to implement a multichannel signal path for ultrasonic air-coupled sonar based on MEMS wideband digital microphones. The proposed solution incorporates the Caravel SoC to manage the output data produced by a custom datapath. The datapath will capture the acoustic signal from an ultrasonic MEMS microphone, demodulate the PDM signal, filter out unwanted spectral components and evaluate signal strength on a base of a configurable threshold. The threshold indicator will control a free-running timer to evaluate the time of flight of an ultrasonic wave, thus range. The proposed solution can be scaled into a multichannel system, reconstructing the acoustic wavefront and thus the angle of arrival of the ultrasonic wave. We will work on the system optimization driven by the resource sharing principle during the design because of the relatively slow intersample interval in a range of a few microseconds.  

Due to the limited resources of the ChipIgnition shuttle, we propose a threshold-based technique of the acoustic wavefront reconstruction; however, the studies and experience gained during this project will help us to develop more advanced digital beamforming techniques

Design goals:

  • Design and evaluate a single channel datapath and control for an ultrasonic range-finder.
  • Optimization of resource consumption of the single-channel solution.
  • Multichannel scaling and implementation of a MIMO system, capable of detecting an angle of arrival based on acoustic wavefront reconstruction and analysis.
  • Post-silicon validation 



DIAGRAMS AND SCHEMATICS

TARGET PERFORMANCE SUMMARY TABLE

 

Parameter

Value

Units

Maximum audio PDM clock frequency 

4.8

MHz

Main clock maximum frequency

50 

MHz

Maximum digital IO occupancy

38

-

Caravel SoC

Yes

-

Maximum audio sampling frequency

400

kHz

 

TEAM MEMBERS

The team is conformed by students of the Department of Electrical and Electronics Engineering, University of the Bio-Bio, Chile, and mentored by an academic Krzysztof Herman, DSc. 

  • Mauricio Montanares Sepúlveda
  • Maximiliano Cerda Cid
  • Sebastian Guajardo Herrera
  • Luis Osses



Owner

Mauricio Alejandro Montanares SepĂșlveda

Summary

The project is oriented to implement a multichannel signal path for ultrasonic air-coupled sonar based on MEMS wideband digital microphones. The proposed solution incorporates the Caravel SoC to manage the output data produced by a custom datapath.

Category

sensor

Process

sky130A

Shuttle Tags

SSCS-21

Tags

mems

sonar

ultrasonic