Embedded Microcomputer Systems Andrew Karpenko 1 Prepared for Technical Presentation February 25 th, 2011

A.R.Drone by Parrot A helicopter with four rotors Internally stabilized Controlled by any device with WiFi Originally designed as a game accessory for the Apple iPhone and iPod touch platforms On-board computer vision Front and down facing cameras for video streaming and object detection Down facing ultrasonic distance telemeter 6 Degree Of Freedom inertial measurement unit 4 ARM7 Microprocessors 1 ARM9 Microprocessor 2 Augmented Reality Drone

Make Platform Make Controller Kit ARM7 Microprocessor Ethernet USB 8 Analog Inputs 8 Digital Inputs/Outputs 4 LEDs ARM7 Microprocessor 48MHz 256KB Memory 3

Development Board 4 Keypad LCD Speaker Motor Bread Board Make Controller Kit Custom development platform designed by Department of Electrical Engineering at UW.

Projects Completed over a 10 week period in groups of two and four: Lab 1 Introduction Lab 2 Scheduling, Input/Output Lab 3 FreeRTOS, PWM and Drone Control Lab 4 Manual and Autonomous Drone Control 5

Lab 1 - Introduction 6 Learn the basics of the Make Controller and the Development Board Controller Review and get familiar with the C programming language C Flash Light Emitting Diodes at different frequencies LEDs Display a message on the Liquid Crystal Display LCD

Lab 2 – Scheduling, Input/Output 7 Create a simple Operating System for handling multiple tasks Build a scheduler that runs tasks in a given time frame OS Read values from an analog sensor Write to and Read from digital Input/Output pins I/O Drive a motor using pulses Vary the motor speed using values gathered from the analog sensors Motor Output motor speed and sensor values on the display LCD

Lab 3 – FreeRTOS, PWM and Drone Control 8 Transition to the FreeRTOS embedded Real Time Operating System that guarantees executed code will meet deadlines RTOS Implement Pulse Width Modulation to drive the motor based on sensor input PWM Implement an Interrupt Service Routine to measure the revolutions of the motor using a speed encoder ISR Read values from the keypad Generate drone commands based on keypad input Fly the AR.Drone by sending commands to it Control

Lab 4 – Manual and Autonomous Control 9 Manually control the drone to navigate a physical obstacle course Manual Control Use a Wii Classic Controller as the control interface for the drone Controller Create an algorithm that will autonomously navigate the drone in a predefined path Autonomous Control

Quadrotor Operation Manual Control 10 Spin Directions Roll (Left and Right ) Pitch ( Forward and Back) Yaw (Rotation) front back left right front back left right front back left right front back left right

Communication Manual Control Drone acts as a Router 3 Port UDP Communication 5556: Commands to the drone 5555: Video feeds from drone 5554: Navigation data from the drone Different devices can connect to different ports 11 Ethernet WiFi

Commands Manual Control Send directional commands Forward/Back Left/Right Rotate Up/Down Send all parameters in one command Back while rotating and ascending Control motor speeds directly ( Dangerous ) 12

Controller Manual Control 13 Wii Classic Controller Pro Forward Up Left/Right Rotate Back Down Takeoff Land Change Camera Change Camera Requires implementing the I 2 C (Inter-Integrated Circuit) bus

Computer Vision Autonomous Control Drone can detect 2D tags and other drones Up to 4 tags Can tell them apart Estimates distance to tags Detection works based on color pattern of outdoor hull, or stickers for the indoor hull Used for Augmented Reality games on the iPhone and iPod touch platforms 14 A. Color pattern on outdoor hull B. Stickers on indoor hull

Path Autonomous Control 15 A A B B Target 1 m height 2 m height 1 m height Points are awarded based on how close the drone is to the starting point at the end of the flight 4m x 4m envelope H Start End

Our Approach Autonomous Control 16 Computer Vision Position Estimation Closed Loop Control …?

Summary A.R. Drone by Parrot Make Platform Development Board Projects Lab 1 – Introduction Lab 2 – Scheduling, Input/Output Lab 3 – FreeRTOS, PWM and Drone Control Project 4 – Manual and Autonomous Drone Control Manual Control Quadrotor Operation Communication Commands Controller Autonomous Control Computer Vision Path Our Approach 17

Embedded Microcomputer Systems Andrew Karpenko University of Washington Seattle 18 Prepared for ELP Onsite Visit Technical Presentation February 25 th, 2011 All images are property of their respected owners. The following images were obtained online: b.jpg b.jpg f020e43594a9c230972d/k/i/kit20_askew.jpg 06f020e43594a9c230972d/k/i/kit20_askew.jpg supporter_logos/NI%20Logo_large2.JPG supporter_logos/NI%20Logo_large2.JPG Any other images found herein have been personally taken by Andrew Karpenko.