STARMAC The Stanford Testbed of Autonomous Rotorcraft for Multi-Agent Control Gabe Hoffmann, Haomiao Huang, Vijay Pradeep, Steven Waslander Aeronautics and Astronautics, Stanford University Claire Tomlin Aeronautics and Astronautics, Stanford University Electrical Engineering and Computer Science, UC Berkeley MURI Review Meeting Frameworks and Tools for High-Confidence Design of Adaptive, Distributed Embedded Control Systems Berkeley, CA September 6, 2007

2 STARMAC Testbed Composition 6 quadrotor helicopters Autonomous UAVs Onboard computation & sensors State and environment estimation Attitude, altitude, position and trajectory control Testbed goals Quadrotor UAV design Cooperative multi-agent control Mobile sensor networks Stanford Testbed of Autonomous Rotorcraft for Multi-Agent Control (STARMAC)

3 Quadrotor Features Vertical Takeoff and Landing (VTOL) Easy to use indoors and outdoors No runway required Safety Rotor kinetic energy distributed to 4 blades Rotors can be within the frame Can fly indoors without harm to user or aircraft Control Design More linear than standard helicopters Maintenance Few moving parts Durable exterior protects contents Cost Can be fabricated in the lab Made of low-cost parts Low maintenance requirements

4 STARMAC Development

5 STARMAC Quadrotor Helicopter Battery Lithium Polymer Brushless DC Motors Axi 2208/26 Sonic Ranger SRF08 Inertial Measurement Unit (IMU) 3DMG-X1 High Level Control Processor Stargate SBC or PC/104 Low Level Control Processor Robostix GPS Superstar II Electronic Speed Controller Phoenix 25 Plastic Tube Straps Carbon Fiber Tubing Fiberglass Honeycomb LIDAR Hokuyo URG-04LX Stereo Vision Videre Systems Small Vision System

6 Quadrotor Helicopter Actuation Yaw Torque Roll/Pitch Torque Total Thrust Two pairs of counter rotating blades provide torque balance Angular accelerations and vertical acceleration are controlled by varying the propeller speeds.

7 STARMAC Network Wifi Netgear Rangemax g+ ≤ 54 Mbps Ground GPS Superstar II Control Laptop Computer Pentium Core Duo 1 GB RAM, 2.16 GHz Running Labview and ssh sessions RS kbps Ethernet 100 Mbps

8 STARMAC Electronics System WiFi b ≤ 5 Mbps ESC & Motors Phoenix-25, Axi 2208/26 IMU 3DMG-X1 76 or 100 Hz Ranger SRF08 13 Hz Altitude GPS Superstar II 10 Hz I 2 C 400 kbps PPM 100 Hz UART 19.2 kbps Robostix Atmega128 Low level control UART 115 kbps CF 100 Mbps Stereo Cam Videre STOC 30 fps 320x240 Firewire 480 Mbps UART 115 Kbps LIDAR URG-04LX 10 Hz ranges Ranger Mini-AE Hz Altitude Beacon Tracker/DTS 1 Hz WiFi g+ ≤ 54 Mbps USB Mbps RS kbps Timing/ Analog Analog RS232 UART Stargate 1.0 Intel PXA255 64MB RAM, 400MHz Supervisor, GPS PC/104 Pentium M 1GB RAM, 1.8GHz Est. & control

9 Low Level Control Event Driven Real-time execution based on Known transmission / receipt rates Measurement of code chunk execution times Fault Tolerant Communication IMU RX SG RX SG TX IMU TX Main (this is an asynchronous event)

10 Information Seeking Target Localization Applications Decentralized Collision Avoidance

11 COMM CLASS GUI & Storage Sensor Processing Controller Planner Real Time Controller GPS LIDAR ROBO GND Estimator GPS Calc State Estimator GPS comm Lidar comm GND comm Flyers Flyer comm GUI (10 Hz) Logging Enviro LIDAR Robo comm signal serial UDP Interfaces Fcn call all any “Flyer Brain” Architecture

12 Questions? … and demo…