ECE415 SDP Design MAPPER: A Perfectly Portable Exploration Robot Rohan Balakrishnan (CSE) Conan Jen (EE) Andrew Lok (EE) Jonathan Tang (EE)

ECE415 SDP Design Project Inspiration 2

ECE415 SDP Design Project Vision Reconnaissance is always important for the military Desired solution is autonomous, small and cheap implementation With importance of human lives, robots are perfect replacement 3

ECE415 SDP Design Decided Implementation Autonomous robotic platform capturing information about its surroundings Wireless communication link will transfer data back to PDA or Laptop Transferred data used to construct a 2-D bird's eye view of the environment 4

ECE415 SDP Design Project Considerations Multiple platform considerations – Non-mobile Leaves very little time for scanning Must be impact hardened Scan rotation depends entirely on trajectory of throw Multiple sensor considerations – Laser Expensive, loses accuracy at range, bulky – Radar Power hungry, large, expensive, complicated – Optical Needs large bandwidth on wireless link, software based distancing detection – Ultrasound Inexpensive, accuracy issues 5

ECE415 SDP Design Project Specs / Scenario Initial Phase – Room Limitations: 20'x20‘, flat floor – Method: rotating ultrasonic sensors – Scan time: 5-15 mins – Stationary walls and large objects (minimum 1'x1') only – No manual intervention, straight movement into room – Wireless communications: 100+ ft 6

ECE415 SDP Design Room Scenario 7

ECE415 SDP Design GUI Mockup 8

ECE415 SDP Design Budget PARTS / BUDGET: Ultrasound Sensor$28 Roomba Create$130 Roomba Standard Rechargable Battery$50 PCB$150 Wireless communication device$27-60 Arduino Clone (ATmega168)Free (M5) Total $

ECE415 SDP Design Block Diagram 10

ECE415 SDP Design Roomba Create Robotics platform from iRobot Provides serial input to the base Has a multitude of sensors built in Allows for addition of parts through expansion port 11

ECE415 SDP Design Standard Roomba Create 12

ECE415 SDP Design Wireless Link Considerations: Bluetooth, RF, WLan Security: Important because of military applications Do not want enemy knowing what you know Do not want false data injection Range: Need to be able to go through objects Link must be robust, cannot fail easily Must be able to deal with interference Jamming / interference is an issue, especially with military applications 13

ECE415 SDP Design Stepper Motor LA23GCK-213 Stepper Motor Provides basic platform for sensor to turn and sweep Used to mount the ultrasound sensor onto 1.8° per step Ultrasound sensor beam 20 ft. ≈ 6° Oversampling max room by a factor of 3 14

ECE415 SDP Design Microcontroller Arduino clone - ATmega168 Based on the larger Wiring development board Rapid development with Processing. Flexibility of AVR C on ATmega 15

ECE415 SDP Design Ultrasound Sensor 16 Sensitivity to Ambient Conditions: Average room temperature changes will cause sensor to report readings of accuracy ± 5%

ECE415 SDP Design Power Sources The Roomba has its own internal battery – 12 AA alkalines or rechargeable equivalent – Expected battery life (1.5 hrs) 5V supply from Roomba, 16V supply from Roomba battery – Pin 8 (5V regulated) – Pin 9 (Battery power unregulated) Power for all our components can be drawn from Roomba 17

ECE415 SDP Design Project Responsibilities Rohan: Map application on computer/Arduino interfacing Conan: Wireless/Ultrasound Andrew: ATMega168/Arduino interfacing Jon: Stepper Motor + Wireless 18

ECE415 SDP Design Rough Timeline 19

ECE415 SDP Design Challenges Ultrasonic sensor may have accuracy issues Roomba movement integration 20

ECE415 SDP Design Questions? Questions? Comments? 21