mechanical engineering 8936 term 8 design project february 3, 2012
TRANSCRIPT
Design Review #1Autonomous Hovercraft
Mechanical Engineering 8936Term 8 Design Project
February 3, 2012
AgendaProject ScopeBackgroundSimulationDesign ConsiderationsHardwareSoftwareProject ManagementFuture ConsiderationsConclusion
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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.
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Background of HovercraftA hovercraft is a vehicle that floats or hovers
on a cushion of pressurized air.A hovercraft consists of:HullSkirtLift FanPropulsion Fan
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Design Parametersα = Hovercraft Angle Headingβ = Hovercraft Angle of VelocityE = Drive ForceF = Friction ForceT = Yaw TorqueM = Mass I = Yaw InertiaK = Dart Effect J = Yaw DragX = Prop Coefficient Relating Ramp up SpeedY = Prop Coefficient Relating Maximum TorqueZ = Coefficient of Friction
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Governing Equations
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Equations of Motion Drive Equation
Yaw Control
Translation Control
SimulationEffects of
Variables on Hovercraft Control
Root Locus & Simulink
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Simulation
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Variable Effect Design Considerations
Mass: MFaster response more damping for smaller
valuesLightweight
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
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Design Consideration
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Motor SelectionPropulsion Motors
Voltage (V) Motor 1 Thrust (g) Motor 2 Thrust (g)
3 5 7
6 8 10
9 15 18
12 32 33
Lift Fan Motors
Temperature (oC)
Motor 1 104
Motor 2 83
Motor 3 61
Design ConsiderationFoam Skirt
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Foam Skirt
Weight (g) 16.474
Relative coefficient of friction High
Young's Modulus 10^9 N/m2, GPa
3.5
Design ConsiderationFabric Skirt
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Fabric Skirt
Weight (g) 9.290
Relative coefficient of friction Low
Young's Modulus 10^9 N/m2, GPa
N/A
Design ConsiderationRubber Skirt
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Rubber Skirt
Weight (g) 34.292
Relative coefficient of friction
Medium - High
Young's Modulus 10^9 N/m2, GPa
0.1
Hardware16F876 PIC2200 mAh LiPo Battery (11.1 Volts) to run H Bridges9 Volt Battery to run PIC
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HardwareSharp GP2Y0A02YK0F IR Range Sensor - 20
cm to 150 cmMaxbotix LV-MaxSonar-EZ0 High
Performance Sonar ModuleDual Axis Gyro Breakout Board IXZ500
±500° / secHMC6352 Compass Module
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SoftwareProgramming in C, Converted to HexCode Will Interpret Sensors to Navigate PathPID Control Algorithm for Cornering
Potential Issues With Errors in Calculations, Sampling Time
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Project ManagementProject ScheduleProject BudgetWebsite
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Project Schedule
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Project Budget
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Starting Budget
Faculty of Engineering $250.00 Group Members $50.00
Total: $300.00
Costs to date
Sonar Range Finder $26.89 Gyroscope $41.19
Digital Compass $37.11 HST/ S&H $24.12
Remaining Funds $170.69
Project Website
www.autonomoushovercraft.yolasite.com
Please Visit!
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Way ForwardMore robust prototypeVideo surveillance Determine system parameters for simulationIntegration of PIC board with sensorsDesigning lift fanPurchase new hardware
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Conclusion
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Project ScopeBackgroundSimulationDesign ConsiderationsHardwareSoftwareProject ManagementFuture Considerations
Thank You!Any Question?
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