HAWK: An unmanned mini Helicopter-based Aerial Wireless Kit for localization Zhongli Liu, UMass Lowell Yinjie Chen, UMass Lowell Benyuan Liu, UMass Lowell Chengyu Cao, University of Connecticut Xinwen Fu, UMass Lowell

Outline  Introduction  HAWK - a mini Helicopter-based Aerial Wireless Kit  Evaluation  Conclusion 2

Wireless Localization Infrastructure: GPS Constellation Target: smartphone Infrastructure: WiFi Access Points 3  Self-positioning: target calculates its own position  Infrastructure positioning: the infrastructure calculates the target’s position  Third party wireless localization of target

Third Party Localization  Localization via received signal strength (RSS)  Broad applications in public safety, cyber forensics, network management 4

Outline  Introduction  HAWK - a mini Helicopter-based Aerial Wireless Kit  Evaluation  Conclusion 5

Problem Definition and Basic Idea Problem Definition: How to locate a wireless target device by HAWK Basic idea: Use the location where HAWK senses the strongest signal strength sending from target device as the location of the target 6

Issues 1.What is the flight route for the helicopter? 2.How to ensure a target will be detected? 3.How to implement reliable waypoints? 4.What is target location? 7

1. What is the flight route for the helicopter? Reasons:  It is a space-filling curve  A level n Moore curve covers all unit squares with the shortest distance  It begins and ends at the same point Moore space filling curve can be used as a flight route 8

 Proper level: flight speed v, square side width d, transmission radius R and transmission interval t  Principle 1: During the flight in a unit square, HAWK senses at least one packet from target in that unit square  Principle 2: To save battery power, a proper level of Moore curve is critical while satisfying Principle 1 (1) 2. How to ensure a target will be detected? 9

 Moore curve is a direct application of the waypoints functionality  Factors such as wind may affect helicopter’s movement during flight  Three parameters of the mini helicopter, pitch, roll, and yaw can be adjusted  PI-control law is written as: ProportionalIntegral 3. How to implement reliable waypoints? (2) 10

 We use the location where the strongest RSS is sensed as the target device’s location  A target device may be located in the unit square where the strongest RSS from the target is sensed or one of its eight surrounding unit squares 4. What is target location? 11

Outline  Introduction  HAWK - a mini Helicopter-based Aerial Wireless Kit  Evaluation  Conclusion 12

Prototype of HAWK  Helicopter: Draganflyer X6 with GPS  Wireless sniffer: Nokia N900  Handheld controller: emergency controller  Software controller on a laptop: control takeoff and flight and receive telemetry including GPS from helicopter  Locator on the laptop: show route on Google map in real time, and download data from N900 for location calculation 13

Example Flight  Mini helicopter, with sniffer, flied over buildings  Sniffer ran Kismet  HAWK identified APs  Google Map showed flight route and APs’ locations 14

Real World Experiments Experiments to locate 12 smart phones on track field  One Nokia N900 with Kismet  Warwalking on the tracks and three different flight routes Result:  Five meters localization accuracy on average for a level 3 Moore curve 15

Demo

Related Work Disadvantages of W.A.S.P (Wi-Fi Aerial Surveillance Platform):  A mini airplane that has to fly at a relatively high speed in order to float in the air  Limited localization and surveillance capability because W.A.S.P cannot satisfy Formula (1) 17

Outline  Introduction  HAWK - a mini Helicopter-based Aerial Wireless Kit  Evaluation  Conclusion 18

Conclusion  Developed a fully functional Mini Helicopter-based Aerial Wireless Kit (HAWK)  Proposed a suite of theories for HAWK conducting accurate localization  Moore curve based flight route, considering flight velocity, target transmission interval and target transmission range  Customized PI control laws for reliable navigation  Conducted extensive real-world experiments to validate the feasibility of HAWK for localization 19

Student Research Competition Silver Medal at Mobicom

21/15 Thank you!

Evaluation – Simulation by ns2 Simulations to validate the hot area (nine unit squares) theory 22

Related Work Disadvantages of W.A.S.P (Wi-Fi Aerial Surveillance Platform):  A mini airplane that has to fly at a relatively high speed in order to float in the air  Limited localization and surveillance capability because W.A.S.P cannot satisfy Formula (1) 23

Comparison of localization strategy for accuracy 24