Alexander Montes McneilElectrical Engineering

Alexander MaerkoElectrical Engineering

Gabriela Calinao Correa

Electrical Engineering & Applied Mathematics

Timothy Robert TuftsComputer Systems Engineering

Low-cost 3DEnvironmentSensingSystem

Alexander MaerkoElectrical Engineering

Alexander Montes McNeilElectrical Engineering

Team LESS

Gabriela Calinao CorreaElectrical EngineeringApplied Mathematics

Timothy Robert TuftsComputer Systems

Engineering

Mario ParenteAdvisor

Background: Mars Rover● Obstacle Avoidance Attempted last

yearo Existing Sonar hardware was old and

unreliable

● We want to upgrade to a more powerful sensing systemo Problems: Price and Outdoor FunctionalityTim

Problem

Light based sensor systems that work

outside areprohibitively expensive!

Tim

SignificancePopularity of ‘Hackathon’

Culture

Ela

Emphasis on

Autonomy in Society

Serious Untapped Potential

Context Society:● Availability of

Autonomous Devices Individuals:● Hackers & Hobbyists

o Pizza Delivery Boto Firefighting Robotso iRobot Roomba®

Ela

System Requirements● Optically Sense External

EnvironmentLmin ≤ 0.5 m ΘH ≥ 45°Lmax ≥ 4.0 m ΘV ≥ 58°

● Output real time 3D frameso Usable speed at least 1 m/so Pixel value = Depth value

● Cost under $500● Work in Full Sunlight

Ela

Design Alternatives● Lidar and Range Finder (sunlight)

o Illuminates a target with a lasero Analyzes the reflected light by taking Phase Difference

● Ultrasonic Systems (sunlight)

o Ultrasonic Transducers for Marine Electronics & Sonar

o Tesla

● Kinect (Perfect cost - $150) o Doesn't work in direct sunlight

Alex

LIDAR Explained● Lidar is a general term but all

forms of lidar involve sending light and analyzing some aspect of the return signal

● The simplest LIDAR measures distanceo Analyzes the time it takes

for a light signal to leave and return to the unit

● Operates in between the UV and Infrared spectrum of EM wavesAlex

Ultrasonic Systems

Alex

$40

Kinect

Alex

LESS Solution

Alex

● The LESS brings a low cost 3D environment mapping system to your backyard

● Design a system of optical improvements to filter out the suns interference with the system

● Use a microcontroller to create a 3D depth chart of the environment and export in a familiar format

Sunlight Solution● Pulsed, Polarized

Laser● Band Pass Filter● Polarized Lens● Normalizing

Alex

Block Diagram

Alex

Subblock: Optics

Alex

Requirements:● Laser

o PrimeSense Diffraction Grating

o Reduce Interference by 90%

o λ = 830 nmo T = constant ± 3°C

● Depth Sensoro 1200x960 pixels

o 30 FPS

Alex

Subblock: Microcontroller/ElectronicsRequirements:● Control Optics

o Laser Pulsing, Temperature Sensor● BeagleBone Black (~$60)

o 512MB DDR3 RAMo 4GB 8-bit eMMC on-board flash

storageo 3D graphics acceleratoro NEON floating-point acceleratoro 2x PRU 32-bit microcontrollersAlex

Subblock: Data ProcessingRequirements:● Input raw Optical Data● Filter Noise from Optical Data● Parallel Processing of Frames

o Latency of ≤ 1 so Throughput of 3 FPS

● Output information for 3D mappingo Depth Frame

Ela

Subblock: Rover

Tim

Requirements:● Navigate to a Target

Locationo Within 10 feet (~3 meters)

● Interface with the LESS unit

● Detect and Avoid Obstacleso Range of 0.5 to 4 meters

● Minimal Cost to Travel Speedo Travel at 0.2 m/s

MDR Deliverables● Complete Optical Unit Schematic

→ Address the following design problems:o Is there an aberration to be accounted for on the CCD

Sensor?o How will Polarization effect the field of view?o Does a higher intensity affect the value of local maximum

in the PrimeSense diffraction pattern?

● Design Thermal Control System for Laser● Confirmation of Rover Functionality

o Test Drive in the Engineering Quad

● Stream test data from Microcontroller to Rover

● Design Artificial Test Data for Processing Software

Tim

Acknowledgements● Professor Jun Yan, UMass Physics

Dept.● Professor Leonard● Professor Parente and MIRSL● SDP14 Team AIR

Sonar/Ultrasonic Systems Explained● Active sonar emits a sound and

analyzes the echo of that soundo Mainly used underwater

● Ultrasonic sensor systems uses the same method but at a much higher frequencyo This makes it more suitable for use in the

atmosphere

Design Alternatives

Alex

● Real-Time Navigation in 3D Environments Based in Depth Camera Data

The Mesa Imaging SwissRanger 4000 (SR4000) is probably the most well-known ToF depth camera. It has a range of 5-8 meters, 176 x 144 pixel resolution over 43.6° x 34.6° field of view. It operates at up to 54 fps, and costs about $9,000. I've seen these used in a number of academic laboratories.

Outline● Background● Problem● Significance● Context● System Requirements● Design Alternatives● Block Diagram● MDR Deliverables● Acknowledgements/Citations● Questions

Ela

Tim Ela

Stubs of faces for slides

Alex Alex

LIDAR

Alex