1 / 59

RAV Remote Aquatic Vehicle

RAV Remote Aquatic Vehicle. Group Members: Matthew Allgeier Kevin DiFalco Dan Hunt Derrick Maestas Steve Nauman Jaclyn Poon Aaron Shileikis. Overview. Objectives Overall Vehicle Design Hydrodynamics Buoyancy Propulsion Low Speed Maneuverability Communications Electronics

lanai
Télécharger la présentation

RAV Remote Aquatic Vehicle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. RAVRemote Aquatic Vehicle Group Members: Matthew Allgeier Kevin DiFalco Dan Hunt Derrick Maestas Steve Nauman Jaclyn Poon Aaron Shileikis

  2. Overview • Objectives • Overall Vehicle Design • Hydrodynamics • Buoyancy • Propulsion • Low Speed Maneuverability • Communications • Electronics • Conclusion • References • Supplemental Information ASEN 4018

  3. Objectives • Mission Statement • Conceive, Design, Fabricate, Integrate, Test and Verify a Remote Aquatic Vehicle (RAV) with active buoyancy and low speed maneuverability that is deployable by a single person. • Mission Goals • Velocity = 7 knots • Rotation Rate = 1 rev/min • Max Depth = 20m • Weight = 130 N ASEN 4018

  4. Overall Vehicle Design • Configuration Alpha • 4 aft movable control surfaces • Shroud is optional • Configuration Bravo • 2 dive planes located in bow • 1 aft rudder (not shown) • Shroud required ASEN 4018

  5. Overall Vehicle Design • Components: • Vehicle Structure – torpedo shaped, compartmentalized • Buoyancy – 2 piston cylinder tanks, 1 fore, 1 aft • Motor – DC electric, reversible, located in tail section • Low Speed Maneuverability (LSM) – 4 vortex jets, 2 fore, 2 aft • Electronics – actuators, multiple onboard sensors, data storage • Communications – radio control ASEN 4018

  6. Hydrodynamics • Design Alternatives • CU: HydroBuff • Myring Hull Contour • Three Section Layout • Two Dive Planes, Four Stabilizers, One Rudder, and Propeller Shroud • Florida Atlantic: SQUID II • Laminar Torpedo Shape Design • Vector Thrusting with Propeller Shroud and Four Stabilizers [3] ASEN 4018

  7. MIT: The Orca 2 • Torpedo Shape • Side, Aft, and Bow Mounted Thrusters • Cornell: CUAV • Cylinder Shaped Hull • Side, Aft, and Bow Mounted Thrusters [3] ASEN 4018

  8. Design Alternatives ASEN 4018

  9. Design-To Specifications • Increase maximum forward velocity to 5-7 knots (HydroBuff achieved about 3 knots) • Be able to manufacture all structural components in-house. • Decrease overall size of submarine. • Increase ability to withstand compressive forces. • Increase structural mass so that extra weights are not required ASEN 4018

  10. Design To Specifications • Myring Hull Contour • Decided to again use a Myring Hull Contour • Efficient mathematical model that minimizes drag for submersible objects. • Ease of repeatability • Proven success, therefore low risk. • Other designs considered include a Torpedo shape and a Rectangular Shape [5] ASEN 4018

  11. Design Issues and Risk • Issues • Duplication of Myring Hull contour design provides very low risk due to proven success. • Machining all products in-house eliminates dependency on outside companies. • Risks • Decreasing size of submarine induces a slight risk on interior components (electronics, batteries, ect..) not fitting. ASEN 4018

  12. Buoyancy • Design Alternatives • Piston Ballast Tank • Pressure Ballast Tank • Vented Ballast Tank • Flexible Ballast Tank • Membrane Ballast Tank • Bellow Ballast Tank • Gas Operated Ballast Tank ASEN 4018

  13. Design Alternatives ASEN 4018

  14. Buoyancy Design Tree ASEN 4018

  15. Design To Specifications • Buoyant Force: ρgV • Volume: Cylinder - L = 600 mm - D = 150 mm Nose Cone - L = 180 mm Tail Cone - L = 270 mm • Buoyant Force = 130.01 N (29.23 lbf) ASEN 4018

  16. Design To Specifications • Max Empty Weight of Submarine must be less than 130 N (29.23 lbf) • Smallest Volume of Buoyancy Tank: 100 mL • Positive Buoyancy of 0.7 % (~1 N Net Force) • Negative Buoyancy of 0.7 % (~1 N Net Force) • Neutral Buoyancy at 50 mL • Increasing Tank Size increases Negative Buoyancy • Pressure Force on Piston at 20 m depth: ~5.4 kN with diameter of 150 mm • Increasing diameter increases pressure force on piston ASEN 4018

  17. Design Issues and Risks • Issues: • Testing Facility for 20 m to 0 m still being investigated • System performance not dependant on depth except for motor strength • Very dependent on weight and volume • If weight is increased volume must increase to provide positive buoyancy • Tank Diameter • Determines Mass Flow Rate and Pressure Force on Piston • Risk: • Sealing critical to design • Piston friction requires seal selection to be important design driver for diameter and piston speed • Safety ASEN 4018

  18. Design Alternatives Propulsion ASEN 4018

  19. Design To Specifications • Requirements • Motor – accelerate to 10 knots. • Propeller – pitch and diameter • Batteries – Provide power to motor for 1 hour of cruise • Shroud • Overall Design • Single propeller in rear of vehicle • Powered by 6-24 Volts • 600-1000 RPM’s per Volt • 50-150 mm propeller diameter • 50-200 mm propeller pitch ASEN 4018

  20. Design To Specification • Motor Power Needed: ~500 W • Calculated on a set velocity and drag • Plot shows relationship between pitch, RPM, and Motor Power ASEN 4018

  21. Design To Specification ASEN 4018

  22. Design Issues and Risks • Issues: • Propeller – manufacturing is very difficult and finding the required prop may be difficult. • Propeller may have to be manufactured in house • Quantitative analysis of shroud is in progress • May have difficulty providing a motor with 24 volts for 1 hour of cruise time • Risks: • Propeller slippage in the water may occur if torque calculations are not correct • Safety ASEN 4018

  23. Low Speed Maneuverability • Design Alternatives • Synthetic Vortex Jets • External Thrusters • Internal Thrusters • Water Displacement System - pumps • Gyros ASEN 4018

  24. Design Alternatives ASEN 4018

  25. Strafe Rotate • Design To Specifications • Vortex Jets • Low Drag • Minimal Space Required • Easy to Manufacture • Electronically complex • Inexpensive • New Concept [2] ASEN 4018

  26. Design To Specifications • Vortex Jets • Length / Diameter = 4 • Zero-mass change • Solenoid selection • Soft shift • Tubular • Low profile • Open frame ASEN 4018

  27. Design To Specifications • Internal • Compact • Low Cost • Required Force > 0.2 N • 150 mm diameter, 1 m length vehicle to rotate 1rev/min • D=1/2 * ρ V2 d L Cd = .2093 N • Conservative calculation • Modeled with all forces experienced at the end of vehicle ASEN 4018

  28. Design Issues and Risks • Issues: • Optimization required for RAV • Latex diaphragm • Frequency of jet oscillations • Duty cycle of solenoids • Exit-hole diameter • Solenoid or piezo-electric disk • Latex slippage • Latex attachment to solenoid • Watertight • Risks: • Corrosion • Not a proven concept • Watertight ASEN 4018

  29. Communication • Design Alternatives • Radio Control • Sonar • Wire • Light ASEN 4018

  30. Design to Specifications • Programmable Controller(s) • # of Channels dependent on # of Actuators • 9 Channel Limit/Controller • Integrated Switch Box increased Switches • 27 or 75 MHz • Switch Box/# Controllers Dependent on $$$ • Antenna Length < 1m (3ft) • Frequency (VHF 30 – 300 Mhz) • Resonant Frequencies • Multiband (Harmonics) vs. Single Band • Half wavelength (feet) ½ λ wavelength, feet = 468/freq, MHz • Quarter wavelength (feet) ¼ λ wavelength, feet = 234/freq, MHz • Risk • Metallic Interference • Signal Loss ASEN 4018

  31. Communications ASEN 4018

  32. Data Acquisition • Design Alternatives • Onboard Data Storage • Data Logger / Software • Software available • Integration is easy • Real Time Telemetry • Transmit Data via Modem • Requires software development • Expensive ASEN 4018

  33. Design To Specifications • Forward Speed • Pressure Transducer • 0-10 knots, +/- 0.1 knots • Depth • Pressure Transducer, Pole • 0-10 m, +/- 0.01m • Rotational Strafe Speed • Observation ASEN 4018

  34. Design Issues and Risks • Issues: • Data Recorder not specified • Sensors not specified • Back up test plans needed • Testing facilities for 20m depth • Risks: • Sensor Failure Backup system verification needs to be developed (i.e. using stop watch to determine speed) ASEN 4018

  35. Electronics System ASEN 4018

  36. Design Issues and Risks • Issues: • Not all components identified • Integration • Risks: • Power Loss • Signal Loss Implementation of “failsafe” to surface • Water Intrusion Water sensor ASEN 4018

  37. Project Management • Organization Chart ASEN 4018

  38. Work Breakdown Structure ASEN 4018

  39. Schedule & Budget • Task List • Drawing Tree • Budget • EEF Proposal • UROP Proposal • Meetings ASEN 4018

  40. Conclusions • Objectives • Overall Vehicle Design • Hydrodynamics • Buoyancy • Propulsion • Low Speed Maneuverability • Communications • Electronics ASEN 4018

  41. References • http://www.heiszwolf.com/subs/tech/tech01.html • Madsen, Chris, Vortex Jet Solid Model • Vehicles • MIT sub http://web.mit.edu/orca/www/ • Cornell Sub http://www.brainteam.org/ • Florida Atlantic sub http://www.oe.fau.edu/~auvcomp/index.html • Density of PVC and Aluminum www.plasticsrecycling.org • Density of Steel www.euro_inox.org/pdf/paper/Cunat_EN.pdf • Prices of Aluminum and Steel http://www.robotcombat.com/store.html • JSC Amateur Club • UUV Report, 2002-2003 • SDCL-DOME-0822, 21 September 2003 ASEN 4018

  42. Questions ? ASEN 4018

  43. Supplemental Information

  44. Propulsion

  45. Propulsion • Equations used in MATLAB analysis of motor power required. RPM: 3000 – 10000 RPM Prop Pitch: 50 – 200 mm/rev Prop Efficiency: 85% Motor Efficiency: 75% Drag: varied based on V and vehicle dimensions ASEN 4018

  46. Propulsion • Requirements • Motor – Most critical, throttle-able, reversible, sufficient thrust to accelerate vehicle to 5 knots, designed for 10 knots. • Propeller – Pitch sized to meet required cruise speed based on motor RPM’s. Diameter sized to reduce tip drag, will be smaller than the diameter of the vehicle. • Batteries – Provide power to motor for 1 hour of cruise. • Shroud – 1 mm tolerance from propeller tip. Other specifications to be determined. • Overall Design • Single propeller in rear of vehicle • Powered by 6-24 Volts • 600-1000 RPM’s per Volt • 50-150 mm propeller diameter • 50-200 mm propeller pitch ASEN 4018

  47. Buoyancy

  48. Buoyancy • Positive Buoyancy: Buoyant Force > Weight • Negative Buoyancy: Buoyant Force < Weight • Neutral Buoyancy: Buoyant Force = Weight Buoyant Force Weight • When Buoyancy System is empty the Submarine must be Positively Buoyant • When Buoyancy System is full the Submarine must be negatively Buoyant ASEN 4018

  49. Buoyancy • MATLAB analysis of buoyancy system Net Force = Buoyant Force – Weight Buoyant Force = ρgV ASEN 4018

  50. Buoyancy • Piston Ballast Tank • Self-Contained • Can be machined in-house • Sealing and pressure issues are minimal • Pressure Ballast Tank • Self-Contained • Can be machined in-house • Very pressure sensitive • Require added sensors [1] ASEN 4018

More Related