Nessie Neutrally-Buoyant Elevated System for Satellite Imaging and Evaluation
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NESSIE NEUTRALLY-BUOYANT ELEVATED SYSTEM FOR SATELLITE IMAGING AND EVALUATION 1 Project Overview Space Situational Awareness (SSA) • Determine the orbital characteristics of objects in space Currently there are only two methods Radar • Expensive Telescopes • Cheaper, but can be blocked by cloud cover Both are fully booked and can't collect enough data Over 130,000,000 estimated objects in orbit 2 Introduction Solution Critical Project Elements Risk Analysis Schedule Our Mission: MANTA NESSIE • Full-Scale SSA UAV • Proof of concept vehicle • Operates at 18000ft • Operates at 400ft AGL • Fully realized optical Scale • Payload bay capability 1 : 2.5 payload • Mass 1 lb • Mass 15 lbs • Contained in 4.9” cube • Contained in 12” cube • Requires 5.6 W of Power • Requires 132 W of Power • Provide path to flight at full-scale 3 Introduction Solution Critical Project Elements Risk Analysis Schedule Stay on a 65,600 ft to 164,000 ft distance from takeoff spot Legend: 10 arcseconds object Requirements centroid identification 5. Point optical Dimness ≥ 13 accuracy, 3 sigma precision system, capture Operations flow apparent magnitude image, measure time and position 4. Pointing and stabilization check, 6. Store image autonomous flight and data 7. Start autonomous Loop descent to Ground Station when battery is low. Constantly downlink 3. Manual ascent position and status above clouds, uplink data to ground station 8. Manual landing, Max 18,000 altitude ft from ground station uplink from ground station 1. System 2. Unload/ Assembly/ Prep. Ground Station End of mission 14 transportation hours after first ascent 4 Land 300 ft (100 yards) from takeoff spot Stay within 400 ft of takeoff spot Legend: 4. Systems check, 5. Continuously Collect Requirements Manual flight acceleration data from Operations flow onboard IMUs Provide power and data connectivity to payload 6. Start manual descent to Ground Station when battery is low. Downlink position 7. Manual landing, and status data to uplink from ground ground station station 3. Manual ascent, uplink from ground station Max 400 altitude ft End of mission when 1. System battery reaches ~20% transportation 2. Unload/ Assembly/ Prep. Ground Station 5 Land 300 ft (100 yards) from takeoff spot Design Solution: NESSIE Torus Shaped Airship ● Torus Shaped Envelope: allows for optical observations vertically ○ Overall Diameter 19.90 ft ○ Inner hole diameter 10.10 ft ○ Has “hard points” for attachment ● Rigid frame: holds all components to the balloon ● Gondola: centrally located and holds payload and propulsion and electronics ● Tail: Provides static stability and control authority 7 Introduction Solution Critical Project Elements Risk Analysis Schedule Design Solution: NESSIE Torus Shaped Airship ● Torus Shaped Envelope: allows for optical observations vertically ○ Overall Diameter 19.90 ft ○ Inner hole diameter 10.10 ft ○ Has “hard points” for attachment ● Rigid frame: holds all components to the balloon ● Gondola: centrally located and holds payload and propulsion and electronics ● Tail: Provides static stability and control authority 8 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Gondola Specifications ● Constructed Carbon fiber sheets ● Gondola holds all critical components ○ Flight Controller: Pixhawk 4 mini ○ Battery: 5200 mAh LiPo 4S ○ Propellers: 15.5”x 5.3 carbon fiber ○ Payload cube: 4.87” cube, 1lb ● Extra space for all wiring and additional items 9 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Gondola Payload Specifications Battery ● Constructed Carbon fiber sheets ● Gondola holds all critical components ○ Flight Controller: Pixhawk 4 mini ○ Battery: 5200 mAh LiPo 4S ○ Propellers: 15.5”x 5.3” carbon fiber Flight ○ Payload cube: 4.87” cube, 1lb Controller ● Extra space for all wiring and additional items Propellers Brushless Motors 10 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Propulsion Specifications: ● Weight of motors and propellers = .902 lbs ● Propeller diameter = 15.5'' ● Max thrust: 14.81 N ● Maximum power in = 730 W ● Actuator on propulsion axle ● Separate electronic speed controller for each motor 11 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Balloon Specifications: ● Material: PVC 0.18 mm ● Weight = 44.03 lbs ● Volume = 888.60 ft3 ● R = 7.50 ft ● r = 2.45 ft ● Net lift = 10 lbs 12 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Balloon Specifications: ● Material: PVC 0.18 mm ● Weight = 44.03 lbs ● Volume = 888.60 ft3 ● R = 7.50 ft ● r = 2.45 ft ● Net lift = 10 lbs 13 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Structural Beams Specifications: ● Material = Carbon Fiber ● Thickness = 0.03” ● Outer diameter= 1.935” ● Weight of each arm = 0.83 lbs ● Weight of tail boom = 1.47 lbs 14 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Structural Beams Specifications: ● Material = Carbon Fiber ● Thickness = 0.03” ● Outer diameter= 1.935” ● Weight of each arm = 0.83 lbs ● Weight of tail boom = 1.47 lbs 15 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Structural Beams 10.87 ft Specifications: ● Material = Carbon Fiber 7.5 ft ● Thickness = 0.03” ● Outer diameter= 1.935” ● Weight of each arm = 0.83 lbs ● Weight of tail boom = 1.47 lb 7.5 ft 16 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Tail Specifications: ● Material = foam and epoxy composite ● Width of foam = .59'' ● Width of epoxy = 0.01 mm ● Control Surface area = 298.7 in² ● Fixed angle of attack = 5˚ ● Lift at 10 mph wind = 2.69 lbf ● Weight = 1.58 lbs ● Inverted vertical tail for less flow distortion from the envelope 17 Introduction Solution Critical Project Elements Risk Analysis Schedule Electronic Components Tattu Li-Ion Flight Controller: Meishuo solenoid Battery PixHawk 4 Mini Arduino Nano 33 Radio: HobbyKing BLE Sense PixHawk Radio Kit Servo Introduction Solution Critical Project Elements Risk Analysis Schedule 18 General Electronics FBD Legend Motor Shaft 5V Power IMU Battery IMU Power GPS Servo MavLink Data Sensor I2C Elevator Servo Controls Servo Receiver Release 14.8V Power Processor Pixhawk 4 Mini Valve Telemetry ESC 1 Motor 1 MavLink UART Ground ESC 2 Motor 2 5V BEC PDB Station LEDs Battery 19 Introduction Solution Critical Project Elements Risk Analysis Schedule Critical Project Elements 20 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gas Envelope Why is this a Critical Project Element? ● NESSIE is a mission driven lighter-than-air airship. In order to meet these requirements, a balloon must be built and interfaced with a gondola. Relevant Requirements ● FR1: System shall support a scaled optical payload. ○ DR1.2: System shall dedicate1 lb to the payload. ○ DR1.5: Payload bay shall provide at least 100° Field of View (FOV). ● FR 2: System Shall operate at 400ft AGL. ○ DR 2.3: System shall be less than 55 lbs. ● FR 3: System shall station keep in altitude and position. ○ DR 3.1: Shall provide sufficient lifting force. 21 Introduction Solution Critical Project Elements Risk Analysis Schedule Balloon Specification Equations 1) Airship mass = mass of ( + + ) displaced air = 2π +ℎ 2 2 2) Geometric relationship sin + + between Radii based on = 2 FOV and optics location 90 + ∗ tan 2 3) Mass of envelope and = 4 π + 2 π helium based on densities 2 2 2 +ℎ ℎ Design Material DR3.1 Unknowns Choices Properties 22 CPE Gas Envelope Evidence Toroidal Balloon Cross-section DR1.2 DR1.5 ft DR2.3 44.08 + 9 + 1 = 54.08 lbs 23 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gas Envelope Requirements Met Requirement How Met Met DR1.2 System shall dedicate 1 lb to the Balloon allows for 1 lb Payload payload. DR1.5 Payload space shall provide a housing Balloon allows for 110° FOV location where an optical system would have a field of view(FOV) over 100 degrees. DR2.3 System shall comply with FAA hobbyist Balloon, gondola, and Payload regulations. (55 lb max takeoff weight) are 54lb DR3.1 The system shall provide sufficient net Balloon will be neutrally buoyant lifting force to attain desired altitudes. at 400 ft AGL at Boulder with full load 24 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Why is this a Critical Project Element? ● NESSIE is a mission driven lighter-than-air airship. In order to meet these requirements, a gondola must be built to carry electrical components and interfaced with the balloon. Relevant Requirements ● FR1: System shall support a scaled optical payload. ○ DR1.2: System shall dedicate 1 lb to the payload. ○ DR1.4: System shall provide a 4.87”x 4.87”x 4.87” payload bay. ○ DR1.5: Payload bay will provide at least 100° Field of View (FOV). 25 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Propulsion axle: ● Maximum normal stress of 62.5 MPa ● Yield strength of carbon fiber is ~ 120 MPaFR1 DR2.2 ● Simplified beam analysis confirmed results 26 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Balloon arms: ● Maximum normal stress of 96.35 MPa FR1 ● Maximum tensile yield strength of carbon fiber is ~ 120 MPa. DR2.2 ● Simplified beam analysis confirmed results. 27 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Requirements Met Requirement How Met Met