Directional SDR-based Local Positioning System Development Team - - PowerPoint PPT Presentation

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directional sdr based local positioning system
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Directional SDR-based Local Positioning System Development Team - - PowerPoint PPT Presentation

Jan 03, 2023 364 likes •710 views

Directional SDR-based Local Positioning System Development Team Crystal Eskander - Project Lead, System Design, Data Collection Jerry Liu - Hardware Development, Triangulation Algorithm Lillian Liu - Software Development, Triangulation

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SLIDE 1

Directional SDR-based Local Positioning System

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SLIDE 2

Development Team

Crystal Eskander

  • Project Lead, System Design, Data Collection

Jerry Liu

  • Hardware Development, Triangulation Algorithm

Lillian Liu

  • Software Development, Triangulation Algorithm

Lekha Adari

  • System Design, Data Collection
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SLIDE 3
  • Goal: To provide an alternative location tracking system to

GPS, potentially to plan against GPS loss (such as jamming or in locations with poor GPS signal).

  • GPS uses satellites; Bermuda is a proof of concept that a

device’s coordinates can be located using radio emitters and directional antennas.

What is Bermuda?

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SLIDE 4
  • Defense
  • Space Exploration
  • Precision Landing
  • Warehouse Navigation
  • Surgery

Applications

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SLIDE 5
  • KerberosSDR
  • Raspberry Pi 3B+
  • WitMotion IMU
  • Adafruit Radio Emitters

System Architecture

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SLIDE 6

System Architecture

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SLIDE 7

KerberosSDR

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SLIDE 8

Lysignal Antenna Freq Range

  • 700 MHz - 2700 MHz

Interelement Spacing

  • 0.1095 meters

Direction of Arrival Estimation

  • Time Difference Of Arrival

(TDOA)

Uniform Linear Array (ULA)

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SLIDE 9

Beamforming

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SLIDE 10
  • Orientation/Bearing Calculations
  • Acceleration
  • UART

WitMotion IMU

(Inertial Measurement Unit)

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SLIDE 11
  • Ubuntu OS
  • Interfaces with

KerberosSDR via USB

  • Interfaces with IMU

via UART

Raspberry Pi 3B+

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SLIDE 12
  • Software Programmable:

○ Frequency, Power, Modulation, Bandwidth, & Data Rate

  • Three Emitters at Differing Frequencies:

○ 912.44 MHz ○ 912.50 MHz ○ 912.575 MHz

Adafruit Feather M0 RFM69 Packet Radio, 900 MHz

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SLIDE 13

Emitter 1 Emitter 2 Emitter 3

Direction Finding

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SLIDE 14

Antenna Quadrants

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SLIDE 15

Low Frequency 912.44 MHz Center Frequency 912.50 MHz High Frequency 912.575 MHz

Frequency Filtering

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SLIDE 16

Triangulation Algorithm

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SLIDE 17

Not Very Accurate Due To:

  • Wind
  • Drift (error accumulation)

IMU Location Tracking

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SLIDE 18

Requires:

  • Radio Emitters
  • Radio Emitters’ locations and

frequencies

  • Bermuda’s starting location

Bermuda’s Triangulation

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SLIDE 19
  • 1. Plot the three known emitter locations.

Bermuda’s Triangulation

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SLIDE 20
  • 2. Get the angle the emitter is coming from.

Bermuda’s Triangulation

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SLIDE 21
  • 3. Bermuda can’t distinguish front from back...

Bermuda’s Triangulation

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SLIDE 22
  • 3. ...so use the IMU to estimate Bermuda’s location and bearing.

Bermuda’s Triangulation

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SLIDE 23
  • 3. ...so use the IMU to estimate Bermuda’s location and bearing.

Bermuda’s Triangulation

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SLIDE 24
  • 4. Incident Angle = slope. Emitter = point. Combine into a line.

Bermuda’s Triangulation

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SLIDE 25
  • 5. Repeat for the other emitters.

Bermuda’s Triangulation

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SLIDE 26
  • 6. The estimated location is the averaged intersection.

Bermuda’s Triangulation

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SLIDE 27

The accuracy of the estimate depends on a lot…

  • Signal Multipath
  • Angle Estimation
  • Emitter Closeness

Triangulation Accuracy

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SLIDE 28

Possible Data Filtering Methods:

  • Outlier Filtering
  • Moving Average
  • Weighted Moving Average
  • Kalman Filtering

Triangulation Filtering

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SLIDE 29

Demo Video

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SLIDE 30
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SLIDE 31
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SLIDE 32
  • Phil Tokumaru, AeroVironment Project Advisor
  • AeroVironment Inc, Project Sponsor
  • Yogananda Isukapalli, Capstone Instructor
  • Kyle Douglas, TA
  • Aditya Wadaskar, TA

THANK YOU!!

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SLIDE 33

Questions?