230 likes | 413 Views
Design and Build of an Autonomous Robotic Paraglider. Level IV Design Project 2006 Project 415 Stephen Craig, Ben Gransden Dr. Damien L eclercq, Dr. Frank Wornle. Autonomous Robotic Paraglider Project. Project Goals
E N D
Design and Build of anAutonomous Robotic Paraglider Level IV Design Project 2006 Project 415 Stephen Craig, Ben Gransden Dr. Damien Leclercq, Dr. Frank Wornle
Autonomous RoboticParaglider Project • Project Goals • Demonstrate the paraglider flying autonomously in a circle of one hundred metre diameter • Provide capability to send commands to the paraglider whilst operational • This seminar will cover • Brief background • Several aspects of the design of the system • Testing and validation of project outcomes
Parafoil ESC Motor Servo Servo System Schematic Dragon12 Laptop 2.4GHzTransceiver Backup Transmitter Gondola MiniDragon BackupReceiver SourceSelect GPS PressureSensor 2.4 GHzTransceiver 11.1V LiPo Battery 11.1V LiPo Battery VoltageRegulators 11.1V LiPo Battery
Parafoil Theory • Similar principle to an airfoil • Inflated wing • Stagnation point • Keeps wing inflated or close to rigid (ADVENTURE Paragliding and Kiteboarding, 2004)
Paraglider Theory Weight Shifting Steering Method • Brake steering • Increases drag on one side of parafoil • Weight shifting • Modifies angle of attack of side of parafoil Rear View Top View Projected flight path Projected flight path
Parafoil Design • Wing loading vs Airspeed • Given • W = 20 N • V = 6 m/s • Required • S = 1.46 m2 • Prototype Parafoil • Parafoil purchased • S = 1.64 m2 For CL ≈ 0.3 (Tennekes, 1997)
Gondola Design • Lift/Drag Ratio Required Thrust 6.6N • Propeller diameter • Calculation of motor power (McCormick, 1995)
Gondola Design • Steering mechanism • Lightweight materials • Low air resistance for propeller
error prone link Crash! Communications • 2.4GHz Transceiver Modules • Unreliable Radio Link • Signal Attenuation • Interference • Noise abcdef… abc¿af.. Paraglider
error prone link Communications • Solution: Reliable Transmission Protocol • Error Detection • 16-bit CRC abcdef…xyz CRC abc¿af…xyz CRC Paraglider != CRC CRC Transmission Error Detected Discard Data…
error prone link error prone link Communications • How does the laptop know whether the paraglider has received the message? • Solution: Packet Identifiers and Timeouts 123 abcdef…xyz CRC 123 abcdef…xyz CRC Paraglider Success! Acknowledged 123+N CRC 123+N CRC Paraglider
Communications Paraglider 150 N=20 170 170 N=25 Timeout 195 Duplicate Detected 170 N=25 Retransmit 195
reliable link reliable link Communications • Other Issues: • Scheduling • Behaviour on Reset • Result: Reliable Link abcdef… abcdef… Paraglider zyxwv… zyxwv…
Kalman Filter • GPS data inaccurate • 5 metres horizontal • 10 metres altitude • Optimal observer • Uses knowledge of noise • Prediction/Correction • Pressure sensor • Fuzzy Controller (Welch and Bishop, 2006)
Testing – Current • Motor mount failure • Line hook ups • New design currently being built • More rigidity • Hook points covered
Testing – Current • Radio testing • 80 metres outdoors • 50% packet loss
Testing - Future • Further testing of Radio and Java • Four major stages of testing • Non-flight mode – Wheeled • Flight mode – Manual (no GPS) • Flight mode – Manual (with GPS) • Flight mode – Autonomous
Demonstration • Run Demonstration