Mechanical Engineering 8936 Term 8 Design Project February 3, 2012
Agenda Project Scope Background Simulation Design Considerations Hardware Software Project Management Future Considerations Conclusion 2
Project Scope The scope of this project is to complete research that will lead to the design and construction of an autonomous hovercraft. The hovercraft will have the ability to maneuver a path that will contain multiple obstacles. This hovercraft can then be used to find an object or give video surveillance and return to its initial launch point. 3
Background of Hovercraft A hovercraft is a vehicle that floats or hovers on a cushion of pressurized air. A hovercraft consists of: Hull Skirt Lift Fan Propulsion Fan 4
Design Parameters α = Hovercraft Angle Heading β = Hovercraft Angle of Velocity E = Drive Force F = Friction Force T = Yaw Torque M = Mass I = Yaw Inertia K = Dart Effect J = Yaw Drag X = Prop Coefficient Relating Ramp up Speed Y = Prop Coefficient Relating Maximum Torque Z = Coefficient of Friction 5
Governing Equations 6 Equations of MotionDrive Equation Yaw Control Translation Control
Simulation Effects of Variables on Hovercraft Control Root Locus & Simulink 7
Simulation 8 VariableEffectDesign Considerations Mass: M Faster response more damping for smaller values Lightweight Moment of Inertia: I Faster response for smaller values, damping effect negligible Mass located to reduce moment of inertia Yaw Damping: J Response speed decreases with increasing values. Damping only signification for J = 0. Low yaw damping desirable Dart Effect: K Unstable for negative values, slower response for increasing values, negligible damping Balance mass as well as possible, front heavy is unstable, back heavy is stable but reduces response time Prop Torque: Y Poor damping at low values, negligible response speed until a critical value where response speed decreases Ensure sufficient torque available for fast response, control system design to compensate for poorer damping Friction: Z Faster response, more damping at higher values High friction desirable
Simulation 9
Design Consideration 10 Motor Selection Propulsion Motors Voltage (V)Motor 1 Thrust (g)Motor 2 Thrust (g) Lift Fan Motors Temperature ( o C) Motor 1104 Motor 283 Motor 361
Design Consideration Foam Skirt 11 Foam Skirt Weight (g) Relative coefficient of friction High Young's Modulus 10^9 N/m2, GPa 3.5
Design Consideration Fabric Skirt 12 Fabric Skirt Weight (g) Relative coefficient of friction Low Young's Modulus 10^9 N/m2, GPa N/A
Design Consideration Rubber Skirt 13 Rubber Skirt Weight (g) Relative coefficient of friction Medium - High Young's Modulus 10^9 N/m2, GPa 0.1
Hardware 16F876 PIC 2200 mAh LiPo Battery (11.1 Volts) to run H Bridges 9 Volt Battery to run PIC 14
Hardware Sharp GP2Y0A02YK0F IR Range Sensor - 20 cm to 150 cm Maxbotix LV-MaxSonar-EZ0 High Performance Sonar Module Dual Axis Gyro Breakout Board IXZ500 ±500° / sec HMC6352 Compass Module 15
Software Programming in C, Converted to Hex Code Will Interpret Sensors to Navigate Path PID Control Algorithm for Cornering Potential Issues With Errors in Calculations, Sampling Time 16
Project Management Project Schedule Project Budget Website 17
Project Schedule 18
Project Budget 19
Project Website Please Visit! 20
Way Forward More robust prototype Video surveillance Determine system parameters for simulation Integration of PIC board with sensors Designing lift fan Purchase new hardware 21
Conclusion 22 Project Scope Background Simulation Design Considerations Hardware Software Project Management Future Considerations
Thank You! Any Question? 23