Alexander Montes Mcneil Electrical Engineering Alexander Maerko Electrical Engineering Gabriela Calinao Correa Electrical Engineering & Applied Mathematics Timothy Robert Tufts Computer Systems Engineering Low-cost 3D Environment Sensing System

Alexander Maerko Electrical Engineering Alexander Montes McNeil Electrical Engineering Team LESS Gabriela Calinao Correa Electrical Engineering Applied Mathematics Timothy Robert Tufts Computer Systems Engineering Mario Parente Advisor

Background: Mars Rover ● Obstacle Avoidance Attempted last year o Existing Sonar hardware was old and unreliable ● We want to upgrade to a more powerful sensing system o Problems: Price and Outdoor Functionality Tim

Problem Light based sensor systems that work outside are prohibitively expensive! Tim

Significance Popularity of ‘Hackathon’ Culture Ela Emphasis on Autonomy in Society Serious Untapped Potential

Context Society: ● Availability of Autonomous Devices Individuals: ● Hackers & Hobbyists o Pizza Delivery Bot o Firefighting Robots o iRobot Roomba ® Ela

System Requirements ● Optically Sense External Environment L min ≤ 0.5 mΘ H ≥ 45° L max ≥ 4.0 mΘ V ≥ 58° ● Output real time 3D frames o Usable speed at least 1 m/s o 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 laser o 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 distance o 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 waves Alex

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 nm o T = constant ± 3°C ● Depth Sensor o 1200x960 pixels o 30 FPS

Alex

Subblock: Microcontroller/Electronics Requirements: ● Control Optics o Laser Pulsing, Temperature Sensor ● BeagleBone Black (~$60) o 512MB DDR3 RAM o 4GB 8-bit eMMC on-board flash storage o 3D graphics accelerator o NEON floating-point accelerator o 2x PRU 32-bit microcontrollers Alex

Subblock: Data Processing Requirements: ● Input raw Optical Data ● Filter Noise from Optical Data ● Parallel Processing of Frames o Latency of ≤ 1 s o Throughput of 3 FPS ● Output information for 3D mapping o Depth Frame Ela

Subblock: Rover Tim Requirements: ● Navigate to a Target Location o Within 10 feet (~3 meters) ● Interface with the LESS unit ● Detect and Avoid Obstacles o Range of 0.5 to 4 meters ● Minimal Cost to Travel Speed o 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 sound o Mainly used underwater ● Ultrasonic sensor systems uses the same method but at a much higher frequency o 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.Mesa Imaging

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

TimEla Stubs of faces for slides Alex

LIDAR Alex