team sasquatch mae 489 4/1/13 alex lee josh anderson nick upham vincent velarde rod nez ryan doyle...
TRANSCRIPT
Team Sasquatch
MAE 4894/1/13
Alex Lee Josh AndersonNick UphamVincent VelardeRod NezRyan Doyle(Left to Right)
To create a stable aerial platform for use in forensic engineering.
• Stable• Reliable• Capable of video recording
Problem Statement
SolutionElectrical Components Housing:Controller, Receiver, Sensors
Batteries (2)Arch (2)
Electrical Speed Controller (4)
Arms (4)
Propeller (4)
Connector Rods (2)
Camera Mount Point
Motors (4)
Requirement Validation MatrixRequirements Validation
Frame- less than 0.1 inches deflection Analysis
Center of Gravity in Center of Frame Inspection
Settling Time less than 5 seconds Analysis and Inspection
Overshoot less than 10% Analysis and Inspection
Sampling period less than 0.04 seconds Inspection
Ability to maintain flight in 10 Mph winds Analysis and Inspection
Quality Video Inspection
300 Foot radio range Testing
3 pound minimum payload capacity Analysis and testing
2 year fatigue life Analysis
100 Newton impact force for frame Analysis
Key Characteristics
• Propellers and motors provide thrust• Powered by LiPo batteries • Stability provided by microcontroller and
sensors• Durable frame
Key Characteristics
Recording
Flight
Thrust
Propulsion
Control
Stability and Response Sensing Command
Electrical Power Frame
Design Process
• Research of prior art showed that multi-rotor craft were most suitable to meet the requirements.
• Further analysis amongst multi-rotor crafts, ranging from three to six rotors, showed that a four rotored craft, or quadcoptor, held the ideal mix of thrust, flight time, and stability.
Project Metrics
Project Metrics
Labor Budget 488
Labor Budget 489
0 2 4 6 8 10 12 14 160
100
200
300
400
500
600
700
800
900
Labor Budget vs. Actuals
Cumulative BudgetActual Budget
Week
Hour
s Wor
ked
Material CostsITEM Budgeted Cost ($) Actual Cost ($)
Motors 80 TBD
ESC’s 80 TBD
Propellers 40 TBD
Microcontrollers 40 TBD
Sensors (IMU, Compass, Altimeter, Proximity)
100 TBD
Wireless Communications 60 TBD
Hand Controller 50 TBD
Power Supply 50 TBD
Frame Materials 160 TBD
Control System Test Stand 50 TBD
Wireless Video System 100 TBD
Fasteners, Wires, and Connectors 20 TBD
Total 780 TBD
Conceptual Design
• Research of Prior Art– “Design and Control of Quadrotors with
Application to Autonomous flying”– Available micro controllers and sensors.– Research into batteries and electric motors.
Conceptual Design
• Candidate Concepts– Single Rotor
– Tri Rotor
– Quad Rotor
– Hex Rotor
Conceptual Design
Preliminary Design Trade StudiesFrame Material• Carbon Fiber• Aluminum• Titanium• Steel
Microcontroller• Arudino Uno• Arduino Mega• Arduino System• PIC
Controller• Bluetooth• Xigbee• RF
Battery Type• LiPo• NiMH• LiFe• NiCad
Motor• Turnigy D3536/9• NTM 35-30• AX-2810Q• ICE
Control Approach• PD• PID• PI
Propeller• 12 x 3.8• 12 x 4.5• 12 x 6• 12 x 8• Slow Fly
Preliminary Design Work Plan
Thrust Analysis
Propeller and Motor Trade
POC Test
Hardware Selection
Battery Analysis
Microcontroller Trade Study
POC Testing of Controls
Hardware Selection
Battery Trade Study
Hardware Selection
Frame Analysis
Frame Design
FEA
Optimization
Analysis Plan:Frame
Frame
Skids Hand Calcs FEA
Motor Hand Calcs POC Testing
Structure Hand CalcsFatigue Matlab
calcs
Deflection FEA
Analysis Plan:Control Systems
Controls
Battery Power Requirements Flight Time POC Testing
Microcontroller PID Testing POC Testing
System Modeling
Simplify System
PID Transfer Function
Response Analysis
Trade Study Example: Microcontroller
Criteria Option A Option B Option C Option D
Cost Approx. $25 $35 $45 $60
Memory 32 Kb 512 Mb 128 Kb 256 Kb
Programming Any Linux/Python Arduino/C++ Arduino/C++
Hardware Compatibility
14 I/O pins6 Analog6 PWM
18 I/O PinsHDMI
39 I/O pins 16 Analog15 PWM
54 I/O pins16 Analog14 PWM
User support Low to moderate Moderate Moderately High High
Issue: Reads sensor data, derives error, uses control algorithm to develop a response
Options: A. In-house AssemblyB. Raspberry PiC. MapleD. Arduino
The final selection is a specialized Arduino which is very cost effective.
Trade Study Example: Motor
Criteria Option A Option B Option C
Power (Watts) 370 350 333
Draw (Amps) 25.5 32 30
Weight (grams) 102 88 70
Issue: Providing thrust for the system.
Options: A. Turnigy D3536/9 B. NTM 35-30 C. AX-2810Q
Option A was selected because it has the lowest draw which is the most important criteria while also having no major disadvantages. Although Option A is the heaviest, having the least draw allows for optimized weight saving by the use of lighter, smaller batteries.
Analysis Example: Fatigue
Problem Statement: Cyclic loadings will cause yielding or fracture within the arms with extended use throughout the life of the arm. Approach: Decrease deflection and stress from their primary source, the motor arms. Use modified Goodman Equation. Approximate the endurance limit as . Assumptions: Cantilever beam model, Assumed maximum theoretical loading conditions. The cyclic loadings consists of , which is the force the arm will experience from the lift of the motors, and , the force applied by the weight of the motor. The distributed weight of the aluminum arm was considered negligible.
Defining Equations:
Results: Due to the miniscule forces applied to the arms by the lift from the motor and the weight of the motor, failure by fatigue will not occur. The factor of safety for infinite life for aluminum () is 26. Conclusion: Fatigue failure is not a concern.
Recommendations: None
Example POC Testing
Purpose of test:Find thrust for
motor and propeller and
flight time
Results: Performance not as expected
Conclusions: Need to redesign test
Effect on design: Battery sizing
Continued POC Testing
Purpose of Test: Repeat Thrust test to find flight time
and loading.Results: Performance as
expectedConclusions: Results valid
Effect on: Battery sizing, forces on frame, and flight time
established
FMEA - SummaryFailure mode
Probability of Failure
End Effect SeverityDetection Method
Ability to detect
Initial RPN
Reduction MethodNew
ProbabilityNew RPN
Fatigue 3Structural
failure8
Operator Observation
9 216 Fatigue analysis 1 72
Power Failure 6Loss of flight capabilities
9.5Operator
Observation5 285
Feedback and quality and Testing
4 190
ESC Failure 4Loss of flight capabilities
9Operator
Observation10 360 Quality ESC's 2 180
Landing skid failure
5Structural damage
6Operator
Observation7 210 Analysis 3 126
Microcontroller Failure
2Loss of Control
10Loss of Control
9 180Quality
microcontroller1 90
Goal Function Optimization:Cost
Initial Estimate
Began Pricing
Frame reduction and better vendors
• Change batteries• Changed camera• Made of carbon fiber
1 2 3 4 5 6 7 8 9 10 11200
400
600
800
1000
1200
CostBudget
Week Number
Cost
($)
Goal Function Optimization:Flight Time
Incorrect Battery
Changed Battery
Lightening Frame
1 2 3 4 5 6 7 8 9 10 110
5
10
15
20
25
30
Flight Time Estimate
Flight Requirement
Week Number
Flig
ht T
ime
(min
)
Solid Model—Final DesignElectrical Components Housing:Controller, Receiver, Sensors
Batteries (2)Arch (2)
Electrical Speed Controller (4)
Arms (4)
Propeller (4)
Connector Rods (2)
Camera Mount Point
Motors (4)
Detail Design
Structural Assembly
Motor Assembly
Propellers Motors
Frame Assembly
Body Assembly
Central Node Arms Top Plate Fasteners
Landing Assembly
Skids Assembly
Connector Rods Arches
Bottom Plate
Detail Design
Controls Assembly
On-Board Controller
Altimeter Arduino Mega 6-Axis IMU Proximity
Sensor Compass XBee
Ground Controller
XBee LCD Screen Control Sticks
Arduino Uno
Power System
Batteries ESCs
Manufacturing Biggest Challenges
• Inaccurate machine shop lead times• No prior knowledge of machining or soldering• No workshop space to store and assemble • Lack of fabrication equipment
Manufacturing
Manufacturing
Development Challenges
• Budget
• Long Lead Hardware
• Hardware Failures
• Difficult Analysis
Hardware Failures
• Hardware failures posed a major problem during the development process.
• ESC failures• Microcontroller failure.• Wire connector failure.• Motor failure.
Validation Summary
• > 0.1 in. deflection (pic of ANSYS)• CG in center of frame (Solidworks output)• 3 lb. minimum payload (thrust test
results)• Settling Time <5 seconds (for these
MATLAB output)• Overshoot <10%• Sampling period <.04 seconds
Validation Summary
• Maintain flight in 10 MPH winds (test results)• Quality Video
(inspection)• 300 ft. radio range (testing)• 2 year fatigue life (analysis)• 100 N impact force (analysis)
Project summary
• Quadcopter stable aerial video footage • Best hardware selection • Designed and optimized frame • Developed own controls system• Integrated design components • Achieved successful flight
Success factors
• Twice a week meetings• Decisions based upon vote• Team strived for optimum output with
feasibility• Detailed pre-planning
Lessons Learned
• Get machining parts into shop early and monitor very regularly
• Provide ample time to test hardware • Budget time correctly for hardware failures