Design and Build of an Autonomous Robotic Paraglider Level IV Design Project 2006 Project 415 Stephen Craig, Ben Gransden Dr. Damien Leclercq, Dr. Frank Wornle

Autonomous Robotic Paraglider Project Project Goals Project Goals Demonstrate the paraglider flying autonomously in a circle of one hundred metre diameter Demonstrate the paraglider flying autonomously in a circle of one hundred metre diameter Provide capability to send commands to the paraglider whilst operational Provide capability to send commands to the paraglider whilst operational This seminar will cover This seminar will cover Brief background Brief background Several aspects of the design of the system Several aspects of the design of the system Testing and validation of project outcomes Testing and validation of project outcomes

Servo Parafoil MiniDragon Pressure Sensor GPS 2.4 GHz Transceiver Backup Receiver Voltage Regulators Gondola LaptopDragon12 2.4GHz Transceiver 11.1V LiPo Battery ESC Motor 11.1V LiPo Battery Source Select Backup Transmitter System Schematic

Parafoil Theory

Similar principle to an airfoil Similar principle to an airfoil Inflated wing Inflated wing Stagnation point Stagnation point Keeps wing inflated or close to rigid Keeps wing inflated or close to rigid (ADVENTURE Paragliding and Kiteboarding, 2004)

Paraglider Theory Brake steering Brake steering Increases drag on one side of parafoil Increases drag on one side of parafoil Weight shifting Weight shifting Modifies angle of attack of side of parafoil Modifies angle of attack of side of parafoil Rear ViewTop View Projected flight path Weight Shifting Steering Method

Parafoil Design Wing loading vs Airspeed Wing loading vs Airspeed Given Given W = 20 N W = 20 N V = 6 m/s V = 6 m/s Required Required S = 1.46 m 2 S = 1.46 m 2 Prototype Parafoil Prototype Parafoil Parafoil purchased Parafoil purchased S = 1.64 m 2 S = 1.64 m 2 For C L ≈ 0.3 (Tennekes, 1997)

Gondola Design Lift/Drag Ratio Lift/Drag Ratio  Required Thrust 6.6N Propeller diameter Propeller diameter Calculation of motor power Calculation of motor power (McCormick, 1995)

Gondola Design Steering mechanism Steering mechanism Lightweight materials Lightweight materials Low air resistance for propeller Low air resistance for propeller

Communications

2.4GHz Transceiver Modules Unreliable Radio Link Signal Attenuation Interference Noise error prone link abcdef…abc¿af..Paraglider Crash!

Communications Solution: Reliable Transmission Protocol Error Detection 16-bit CRC Paraglider error prone link abcdef…xyzCRC abc¿af…xyzCRC != Discard Data… Transmission Error Detected

Communications How does the laptop know whether the paraglider has received the message? Solution: Packet Identifiers and Timeouts 123+NCRC error prone link Paraglider error prone link abcdef…xyzCRC 123 abcdef…xyz123 CRC123+N Success! Acknowledged Paraglider

Timeout Communications Paraglider Retransmit 150N= N= N= Duplicate Detected

Communications Other Issues: Scheduling Behaviour on Reset Result: Reliable Link Paraglider abcdef… reliable link zyxwv…

Kalman Filter

GPS data inaccurate GPS data inaccurate 5 metres horizontal 5 metres horizontal 10 metres altitude 10 metres altitude Optimal observer Optimal observer Uses knowledge of noise Uses knowledge of noise Prediction/Correction Prediction/Correction Pressure sensor Pressure sensor Fuzzy Controller Fuzzy Controller (Welch and Bishop, 2006)

Testing – Current Motor mount failure Motor mount failure Line hook ups Line hook ups New design currently being built New design currently being built More rigidity More rigidity Hook points covered Hook points covered

Testing – Current Radio testing Radio testing 80 metres outdoors 80 metres outdoors 50% packet loss 50% packet loss

Testing - Future Further testing of Radio and Java Further testing of Radio and Java Four major stages of testing Four major stages of testing Non-flight mode – Wheeled Non-flight mode – Wheeled Flight mode – Manual (no GPS) Flight mode – Manual (no GPS) Flight mode – Manual (with GPS) Flight mode – Manual (with GPS) Flight mode – Autonomous Flight mode – Autonomous

Demonstration Run Demonstration Run Demonstration Run Demonstration Run Demonstration

Questions?