COMET:
Spring Final Review
April 21, 2014
Team members: Julia Contreras-Garcia Emily Ehrle Eric James Jonathan Lumpkin Matthew McClain Megan O’Sullivan Benjamin Woeste Kevin Wong
Customer: Lt. Joseph Ausserer, USAF University of Colorado Boulder
Outline • Project Overview
▫ Objectives
▫ Requirements
▫ System block diagram
• Design Description
• Test Overview
• Test Results
• Systems Engineering
• Project Management
Systems and Management
Testing Design
2
Project Overview
Models
Test Stand
Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power Dissipater
Project Purpose and Objectives
Systems and Management
Testing Design Project Overview
Project Description • Design and build a Power Extraction Unit (PEU) for a
JetCat P90-RXi mini-turbojet engine (shown below) that will generate 500 Watts of electrical power at 24 VDC.
• Sponsored by Air Force Research Laboratory’s Aerospace Propulsion Outreach Program (APOP)
4
Generator
Harness Engine
JetCat P90-RXi in stock configuration
Solid Works model Systems and Management
Testing Design Project Overview
Applications • Power extraction devices could be used on variety of military and
civilian Unmanned Aerial Vehicles (UAVs)
• Additional power would replace batteries used to power avionics and/or sensors
• Power extraction unit to weigh
less than equivalent battery,
extending maximum flight time
or flight distance
5
Systems and Management
Testing Design Project Overview
Objectives • Level one
▫ PEU must generate power at 24 Volts DC ▫ PEU must produce this power after the engine has been running no
longer than 1 min 20 s, twice the average start up time ▫ Engine and PEU must be compatible with the WPAFB test stand
• Level two ▫ Reducing thrust by no more than 25% ▫ Increasing specific fuel consumption by no more than 50%
• Level three ▫ Adding no more than the weight than an equivalent battery pack with 30
minutes of power (8 lbs) ▫ Producing 500 W throughout the engine’s RPM operating range
• Level four ▫ PEU to be entirely external to the JetCat engine, making the most
modular solution.
• Red are not met, Green are predicted to be met
6
Systems and Management
Testing Design Project Overview
Design Description
Systems and Management
Testing Design Project Overview
Design Description
8
Systems and Management
Testing Design Project Overview
• Design solution overview
▫ 3-phase brushless motor to act as power generator
▫ Motor has to act as starter until engine can run by itself (~35,000 RPM)
• Critical subsystems
▫ Mechanical
Commercial coupler to connect
engine and motor shafts
Alignment harness to align shafts
▫ Electrical Control switching of motor
between startup mode and power
generation mode
Power conditioning circuitry to
convert AC signal to DC
▫ Software Data acquisition
Modeling
Detailed System Block Diagram
9
Rotor Dynamics
Engine Power Model
P90rxi Engine
Motor Controller Circuitry Motor Controller
(Phoenix 80)
Power
Regulation
Power
Dissipation
Test Stand
Shaft
coupler
Three phase 9.33-16.00Vpp 6.27-5.02 Amps
Direct Current 24 V 2.0 Amps
Motor
B40-8L-
DD
35,000-42,000 RPM 0.0487 Nm – 0.0390
2 kHz 10V PWM motor driving signal
50 Hz Servo PWM
Throttle Signal
Information used to Verify Models
Manufactured
by COMET
Systems and Management
Testing Design Project Overview
Critical Project Elements
10
Systems and Management
Testing Design Project Overview
• Generating electrical power
▫ Req. 1.0 – The design solution shall generate 500 Watts of electrical power
• Attaching motor to engine shaft to provide torque transfer
▫ Req 3.1 – The rotational energy of the main engine shaft shall supply the energy needed via a generator.
• Aligning motor shaft and engine shaft to mitigate vibrations
▫ Req. 3.4 - The design solution shall maintain the engine balance.
• Switching circuitry to force motor to start engine up and then switch to generate electricity
• Convert three phase AC power output from motor into DC power
▫ Req. 2.4 - Power generated shall be transmitted using 24 V DC.
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Test Overview
Systems and Management
Testing Design Project Overview
Testing Overview: Major Tests
12
Systems and Management
Testing Design Project Overview
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Test Name Category Location of Execution Completed
Engine Characterization Test Mechanical Software
Boulder Airport ✔
Low RPM Test Mechanical Electrical
Aerospace Instrument Shop ✔
Circuitry Switching Test Electrical Aerospace Instrument Shop ✔
Final System Test Mechanical Electrical Software
Boulder Bomb Squad Facility
• Completion defined as accomplishing test purpose, (e.g. verifying requirements, verifying models, verifying functionality etc.)
Engine Characterization Test • Test Purpose:
▫ Verify MATLAB Simulink engine model for stock engine configuration
▫ Provided baseline engine performance information
• Location: Boulder Airport
• Requirements Verified:
13
Req # Requirement Text
1.2.1 A method of measurement of fuel flow shall exist.
4.1.1 The test stand shall support clamps that are fitted to the engine.
4.1.2 The test stand shall have an axial load cell for means of measuring thrust.
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Systems and Management
Testing Design Project Overview
Low RPM Test
14
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Test Purpose: ▫ Verify shaft connection for
RPM’s between 0-15,000
▫ Verify motor controller circuitry ability to drive motor
• Location: Aerospace Instrument Shop
• Requirements Verified: ▫ No direct requirements
verification, functional test only
Systems and Management
Testing Design Project Overview
Motor Controller to Power Regulator Circuitry Switching
15
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Test Purpose:
▫ Verify system can properly switch between motor driving and power generating modes
• Location: Aerospace Instrument Shop
• Requirements Verified:
Req #
Requirement Text
2.2.3 Power regulator shall be able to accept voltage input from generator.
Systems and Management
Testing Design Project Overview
Final System Test
16
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Test Purpose:
▫ validate entire system can perform to expected standards
• Location: Boulder Bomb Squad Facility
• Requirements Verified:
Req # Requirement Text
1.1 The design solution shall not decrease stock thrust by more than 25%.
1.1.1 The design solution shall not output torque high enough such that it will stall the engine.
1.2 The design solution shall not increase the thrust specific fuel consumption by more than 50%.
1.3.1 The design solution must operate above 35,000 RPM, the bottom edge of the engine idle range.
2 Power generated shall be transmitted using 24 V DC current.
3 The design solution shall be able to derive power from a JetCat P90-RXI engine.
3.1 The rotational energy of the engine shaft shall be converted into electrical energy via a generator.
3.4 The design solution shall maintain the engine balance.
4 The design solution, when integrated with the JetCat P90-RXI engine, shall interface with the test stand designed by the customer and the test stand available through CU.
4.1 The dimensions of the design solution integrated with the engine shall not exceed those shown below in Figure 2.4-1.
Systems and Management
Testing Design Project Overview
Final System Test
17
Test Stand Engine
Harness
Shaft Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
Measurements Instrument
Output Voltage Direct DAQ input
Output Current Pololu +/- 31 A current sensor
Fuel Flow Rate Equiflow PVDF 0045 flow meter
Engine Thrust Test Stand Button Load Cell
RPM Generator output signal
Load Cell Fuel Tank
Flow Meter
DAQ Chassis
NI
92
05
NI
94
01
NI
92
34
ECU
Engine Generator
Motor Controlling
Circuitry
Voltage Rectifier
Power Dissipater
Current
Voltage
Relays
~30 ft
LabVIEW
Boulder Bomb Squad Dugout
DAQ USB cable
Earth Berm
USB Webcam
Repeater
RPM 35,000 to ~56,000
Test Results
Systems and Management
Testing Design Project Overview
Engine Characterization
19
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Systems and Management
Testing Design Project Overview
• Acquired average thrust and average fuel flow rate vs. RPM for the P90-RXi engine
• Baseline data for later performance effect analysis
Coupling System
20
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Req # Requirement Text Verified by:
3.1.2 Connection shall be secure from 0 to 60,000 RPM Coupler torque test
3.3.1 Electric motor and engine shafts shall be held in alignment so the shafts are not offset by >0.15 mm (0.0059 inches) and 1.5°
Coupling system integration/inspection
Systems and Management
Testing Design Project Overview
Coupling System
• Commercial-off-the-shelf coupler rated to operate at 42,000 RPM, above idle speed (35,000)
▫ Shafts began slipping in coupler at 0.7 Nm
Max engine torque of 0.193 Nm
Factor of safety (FOS) of 3.63
Uncertainty in measurement, ~0.01 Nm
Uncertainty does not affect meeting the requirement
• Coupler limits engine operational range
▫ Coupling method from original design would operate over larger part of operational range
▫ To fulfill all original design requirements, new coupler or coupling method would be required
21
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Req # Requirement Text Verified by:
3.1.2 Connection shall be secure from 0 to 60,000 RPM Coupler torque test
Systems and Management
Testing Design Project Overview
• Alignment Harness
▫ Precision milled for predicted offset of 0.0005” from milling accuracy
Reduced during assembly due to human inaccuracies
▫ Max measured offset between shafts of 0.0034”, for FOS of 1.74
Uncertainty of 0.001” from caliper accuracy
Even with max error, still within requirement range with FOS of 1.34
▫ Angular offset was 0.16°, for factor of safety of 9.4
Uncertainty of 0.23°, from 0.01” measuring inaccuracy
Even with max error, have FOS of 3.85
Coupling System
22
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Systems and Management
Testing Design Project Overview
Req # Requirement Text Verified by:
3.3.1 Electric motor and engine shafts shall be held in alignment so the shafts are not offset by >0.15 mm (0.0059 inches) and 1.5°
Coupling system integration/inspection
Motor to be used as Starter/Generator
23
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Req # Requirement Text Verified by:
1.0 PEU shall generate electrical power. Full-system test
1.3 PEU must operate above 35,000 RPM, the lower edge of the engine idle range. Full-system test
• New motor controller selected after original was shorted
▫ Selected based upon availability and functionality (from Aerospace Electronics shop)
Systems and Management
Testing Design Project Overview
Parameter Required Phoenix 80
Current 15A 80A
Speed (2 pole) 35,000 210,000
Voltage 16V 24V
New Motor Controller System Circuitry
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Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller Power
Regulator
Power
Dissipater Models
PWM generator
Averaging Circuit
Summing amplifier
Timing chip
comparator
Relays Power
Systems and Management
Testing Design Project Overview
End of motor control circuit comparison
25
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Systems and Management
Testing Design Project Overview
Frequency: Model: 49.8 Hz Measured: 48.9 Hz Error: 1.84% Amplitude: Model: 5V Measured: 4.94 V Error: 1.2% Duty Cycle: Model: 5.8 % Measured: 6.0 % Error: 3.45%
Power Regulation
26
Req # Requirement Text Verified by:
2 Power generated shall be transmitted at 24 VDC Full-system test
2.2.1 Power regulator shall keep the max ripple below 2.4V Power reg. funct. test
2.2.3 Power regulator shall accept voltage input from generator Motor Controlling-Power Regulating switching test
2.2.4 Power regulator shall accept input frequencies of 1750 - 6250 Hz Full-system test
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
To Ground
• 50 Watt DC-DC regulator outputs 24 Volts ▫ Generator Voltage
drives power limitation
• Voltage ripple of 0.5 Vpp
Bridge Rectifier Smoothing Capacitor DC-DC Regulator
8.05-14.72 V Peaks
24 Volts 0.5 Volt Ripple
3-phase 9.33-16V
8.05-14.72 V ~0.4 Volt Ripple
Systems and Management
Testing Design Project Overview
Power Regulation: Rectifier
27
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Test in two parts due to limitations of function generator
• 6 Vpp input from 3 synchronized signal generators
Systems and Management
Testing Design Project Overview
Power Regulation: Rectifier
28
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Slightly higher voltage drop than expected
▫ Expect regulator turn on at 39,000 instead of 37,800 RPM
Systems and Management
Testing Design Project Overview
Expected Measured
Voltage drop 1.28 V 1.6 V
Voltage between input and ground Voltage at input to DC-DC regulator
Power Regulation: Regulator
29
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Test in two parts due to limitations of function generator
• Used DC power supply to provide voltage input
• Output loaded with power dissipater
Systems and Management
Testing Design Project Overview
Power Regulation: Regulator
30
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Voltage output fails original objective of 24-28V output
▫ Output will be corrected before demonstration to Air Force in Late May
Systems and Management
Testing Design Project Overview
Required Expected Measured Error
Voltage 24-28 V 24.0 V 23.8 V 0.8%
Ripple 2.4 V 0.24 V 0.24 V 0.2%
Power (Goal) 500 W
48 W 47.95 0.1%
• Power output fails original objective of 500Watts
▫ Due to lack of COTS regulators capable of boosting 9V to 24V at 500W
▫ Insufficient time to design custom regulator
DC-DC regulator output
Low RPM Test
31
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Systems and Management
Testing Design Project Overview
• Verified the motor controller circuitry controls the ESC
• Verified the ESC can smoothly commutate to motor from 0-15,000 RPM
• Verified coupler was able to transmit torque between engine and motor
Measured BLDC motor driving signal from Oscilloscope
BLDC motor droving signal from motor control theory application note
Motor Controller to Power Regulator Switching Test Results
32
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Verified circuitry could switch between the motor controller side and the power regulator side
• Picture shows oscilloscope probing on the power regulator side
Systems and Management
Testing Design Project Overview
Motor Controller being used to drive motor
Input to Power Regulator
Shows Relays Switched Expected result seen, signal went from 0V to 5.4V
Power Dissipation
• A 2 ohm and 10 ohm resistors dissipate the 48 Watts generated
▫ Measure voltage drop across resistor to verify 24 Volt output of DC-DC regulator
▫ Current sensor used in conjunction to verify power output matches predictions
33
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Req # Requirement Text Verified by:
2.3 A board shall be created to verify the power output of the power regulation system. Power dissipation functionality test
Systems and Management
Testing Design Project Overview
• A buffer op amp has been added since TRR to make the voltage divider’s impedance compatible with DAQ measurements
Power Dissipation: Results
34
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Dissipater used to verify power output of system
▫ Uncertainty is 1.2% of expected system power
Systems and Management
Testing Design Project Overview
Max Uncertainty
Voltage 0.04 V
Current 0.03 A
Power 0.58 W
Engine Model Predictions
35
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Engine Model (no-load) predictions: Verified Engine Model (load) predictions: To be Tested • Predictions from model indicate requirements will
be met. • Predictions will be verified during Full System Test
Req # Requirement Text Verified by:
1.1 Not decrease stock thrust by >25% Full-system test
1.2 Not increase stock thrust specific fuel consumption by >50%
Full-system test
3 Derive electrical power from a JetCat P90-RXI engine at 24 V DC.
Full-system test
Systems and Management
Testing Design Project Overview
Final System Test: Status
36
Test Stand Engine
Harness
Shaft Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Currently having problems starting the engine with the integrated design solution ▫ Error: Engine fails due to a temperature bound error
• Cause has been narrowed down to 3 possibilities: 1. Extra fuel forced into system is increasing temperature
2. Engine’s exhaust gas temperature thermocouple is malfunctioning
3. Reduced mass flow due to inlet impedance is causing overheating
• Next Steps: ▫ Iterative testing with decreasing fuel input to see when temperature drops
enough for engine to run
▫ Iterative testing of changing EGT thermocouple position in exit flow
▫ Reduce RPM engine needs to reach to run
Systems and Management
Testing Design Project Overview
Overall Project Results
37
Test Stand Engine
Harness
Shaft Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Did not achieve customer’s original goal of 500W power generation over the operational range of the engine
▫ Had to take off-ramp design solution due to supply chain problems
▫ Original design was modeled and predicted to achieve customer’s goals
▫ 48 Watts predicted
• When these predictions are verified by final system test, the results can be scaled up to original design goals
Systems and Management
Testing Design Project Overview
Parameter Expected Required
Output Voltage
24 V 24-28V
Thrust Reduction
8-10%
Overall Project Results
38
Test Stand Engine
Harness
Shaft Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Original design would have been able to satisfy all functional requirements ▫ Original starter motor/generator would have produced 18V at ~60,000
RPM
▫ Original Power Generating range was 60,000-112,000 RPM, ~55% of engine operational range
▫ Original DC-DC regulator in Power Regulator Subsystem required 18V to begin generating 500W of power.
▫ Custom coupler could be ordered that would operate up to 100,000 RPM, increasing the operational range
Systems and Management
Testing Design Project Overview
System Engineering
Systems and Management
Testing Design Project Overview
Systems Engineering Summary
40
• Define project objectives ▫ Customer-defined requirements ▫ Produce 500W at 24VDC
• Define system requirements ▫ System-level requirements ▫ Minimize impacts on stock system mass,
thrust, specific fuel consumption
• Concept generation and selection ▫ Trade studies and analyses
• Preliminary engineering design ▫ Off-ramps: Lower RPM starter generator,
lower rated coupler, passive signal conditioning
• Component and subsystem testing ▫ Electrical subsystem: Power regulation and
signal conditioning ▫ Mechanical subsystem: Generator
alignment harness, coupling system
• Integration testing • Full-system testing
Systems and Management
Testing Design Project Overview
Work Breakdown Structure
Lessons Learned
41
• Plan for supply chain failures ▫ JetCat not providing original motor ▫ Set hard dates for taking off-ramps ▫ Set margins for other unexpected delays
• Outcome of project has strong dependency on understanding of the schedule ▫ Major milestone: Receive JetCat motor ▫ Electrical: Could not measure signals without
motor ▫ Mechanical: Could not begin manufacturing of
alignment harness
Systems and Management
Testing Design Project Overview
Systems Engineering Issues
42
• Interface and communication with suppliers of critical project elements
▫ Poor/lack of communication from JetCat
▫ No updates about the status of motor
▫ Never received motor from Germany
• Many design changes throughout spring semester
▫ Catch-up from lack of design in the fall
▫ Constant changes to subsystem/integration tests
▫ Devise and plan for contingency off-ramp plans
Systems and Management
Testing Design Project Overview
Project Management
Systems and Management
Testing Design Project Overview
Project Management Summary
44
• Goal: to help the design process operate as smoothly as possible ▫ Understanding of project as a whole ▫ Allocate help where it is needed most ▫ Be aware of schedule and if project is on track or
not
• Key project management lessons learned ▫ Allow more time margins ▫ Do not rely on suppliers/JetCat ▫ Budgets can cause significant delays in project
Obtaining parts sooner would have given more time margins at the end of the project
Systems and Management
Testing Design Project Overview
Budget
45
• Large variation in budget due to team taking off ramp
• Significant over runs of cost in testing area offset by drops in cost of generator and alignment harness
Systems and Management
Testing Design Project Overview
$0.00
$500.00
$1,000.00
$1,500.00
$2,000.00
$2,500.00
$3,000.00
Expected Vs. Actual Expenditures Predicted Cost
Actual Cost
Major Differences in Cost
Total Over budget $1,051.15
Engine $321.00
Other
Broken ECU $591.50
Broken GoJett GSU $184.99
Testing
Flow Meter inserts $60.66
Custom ECU Cable $168.49
Lab Battery Charger $209.99
New Test Stand Battery $86.99
Hours Direct Cost Total Cost
Fall 1,327 $41,475 $124,425
Spring (As of 4/18/14)
1,916 $59,866 $179,597
Total 3,243 $101,341 $304,022
Total project funds spent: $6155.86
Questions?
Systems and Management
Testing Design Project Overview
Backup Slides
Systems and Management
Testing Design Project Overview
Overall Project Results
48
Test Stand Engine
Harness
Shaft Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
• Requirements not verified: ▫ Requirements specific to original 500W generation system
Systems and Management
Testing Design Project Overview
Req #
Requirement Text Reason for Non-verification
1 The design solution shall generate 500 W of electrical power.
Off-ramp design solution not designed to produce 500W
1.3 The design solution shall generate the required power while the engine is operating between 35,000 and 125,000 RPM
The “required power” refers to 500W, which the off-ramp design solution would not be able to produce
2.2.2 Power regulator shall be able to supply 21 Amps. 21 amps is from the 500W design solution
3.2
The generator shall be designed such that the torque from the JetCat P90-RXI engine is sufficient input to generate 500 W at the lowest operational rotation rate, 35,000
Off-ramp design solution not designed to produce 500W
3.5
The design solution shall begin to generate 500 W after the engine has been running for one minute and 20 seconds, twice the start up time of the engine.
Off-ramp design solution not designed to produce 500W
Engine Test Fire Set Up
49
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Req #
Requirement Text Verified by
1.2.1 A method of measurement of fuel flow shall exist.
Inspection
4 The design solution, shall interface with the test stand designed by the customer
Final Demonstration at WPAFB
4.1.1 The test stand shall support clamps that are fitted to the engine.
Inspection
4.1.2 The test stand shall have an axial load cell for means of measuring thrust up to 25 lbs.
Inspection
Test Stand
unscrew
unscrew
Pull off
unscrew
50
Coupling System: Additional Tests • Coupler torque test
▫ Test if threaded engine shaft has enough surface area to make a secure connection to coupler
▫ Insert engine shaft into coupler and apply known torque using lever arm and known weight
▫ Find torque at which shaft slips in coupling
▫ If torque reaches 1 Nm (10x greater than expected torque of 0.1 Nm), test will stop without testing to failure
▫ Extra coupling purchased in case coupler is marred during test
▫ If slip occurs before 1 Nm, shaft will be inserted into other side of coupler and adhesive will be used to fill thread gaps
▫ Torque will be applied and measured again after adhesive sets
• Stiffness test ▫ Verify designed harness system is stiffer than stock system
▫ Hang weight from stock starter
▫ Measure displacement
▫ Calculate displacement expected from designed system using and substituting the force from the physical test
51
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
Shaft Coupler
Engine shaft simulator
Lever arm
Known weight, added incrementally
Stock starter
displacement
Known weight
Low RPM Test: Additional Details
52
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Measurements Instrument Sampling Rate & expected output
Purpose of Measurement
Shaft RPM Engine Ground Support Unit
~1 Hz 0-6,000 RPM
DATA NOT BEING RECORDED Meant as a display of current RPM, not a data recording device. If resonant frequency found the RPM will be recorded by hand.
Frequency Response
PCB +/- 2300 g accelerometer
~25kHz 0-2 g’s
Monitoring vibrations during the test will help reveal any shaft misalignments past the tolerances of the shaft coupler. Measurements will either verify that no natural modes are excited and shafts are aligned or show high amplitude vibrations due to shaft misalignment
Purpose: To ensure shaft connections are stable to ~6,000 RPM Facility: Senior Projects Room or Buseman Advanced concepts lab
Motor Controlling to Power Regulator Switching Test: Additional Details
53
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
Measurements Instrument Sampling Rate & expected output
Purpose of Measurement
Voltage into Power Regulator
Multimeter N/a 0-1.6 V
DATA NOT BEING RECORDED Measurement is to prove that the relays are switching to the power regulator circuitry. Voltage from 6,000RPM is not high enough to pass the DC-DC regulator
See Low RPM Test additional details slide for other measurements
Purpose: To ensure the relays can successfully and properly switch between the motor controlling circuitry and the power regulating circuitry Facility: Buseman Advanced concepts lab
Power Regulator Functionality Test: Additional Details
54
Budget Subsystems Schedule Project Overview
Purpose: To verify the power regulator is working properly Facility: Tim May’s Electronics Lab The Signal: 3-phase sinusoidal wave, 120o phase shift between each sine wave during the test voltage will vary between 9.33-16V to simulate generator signal at 35,000-60,000 RPM
120o 240o 0o
+V
-V
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
The Function Generators: Three function generators will be used to simulate this signal. All 3 will be synced using the built in syncing channel, then function generator 2 will have a 120o phase shift and function generator 3 will have a 240o phase shift
Power Dissipater functionality Test: Additional Details
55
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
Measurements Instrument Sampling Rate & expected output
Output Voltage Direct DAQ input 5 Hz 5-24 V
Output Current Pololu +/- 31 A current sensor
5 Hz 0-5 V (corresponding to 0-2 A)
Purpose: to verify the power dissipation system can dissipate at least 50W of power. Functionality includes the current and voltage sensors as well as the labview VI to read and record current, voltage, and power. Facility: Trudy’s Electronics Lab
Selection of New Starter/Generator
56
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
To
rq
ue
(m
Nm
)
Angular Velocity (rad/sec)
Motor Torque/Speed Curve (0,63.13)
(2932.15,0)
Current Starter
𝐾𝑒𝑚𝑓 =𝑉
𝑟𝑎𝑑/𝑠=
𝑁𝑚
𝐴=
0.06313
28= 0.0023
𝑁𝑚
𝐴
𝑉𝑒𝑚𝑓 = ω𝐾𝑒𝑚𝑓 = 628.32 0.0023 = 1.42𝑉
𝑅1 = 𝑉𝑜𝑝𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔
𝐴𝑠𝑡𝑎𝑙𝑙=
6
28.08= .214Ω
𝑉𝑎𝑝𝑝𝑙𝑖𝑒𝑑
+
-
I
𝑉𝑒𝑚𝑓
𝑉𝑑𝑟𝑜𝑝 𝑎𝑐𝑟𝑜𝑠𝑠 𝑅1 = 3.24𝑡𝑒𝑠𝑡 − 𝑉𝑒𝑚𝑓 = 1.82𝑉
𝑉 = 𝐼𝑅 → 𝐼 =𝑉
𝑅=
1.82
.214= 8.52𝐴
28.08A
0.85A
τ𝑚 = 𝐾𝑇𝐼 = 0.0023 8.52 = 0.02𝑁𝑚
𝐼 =τ𝑚𝐾𝑇
=0.02
0.0025= 8𝐴 + 2.3𝐴 = 10.3𝐴
𝐹𝑂𝑆 = 𝑚𝑜𝑡𝑜𝑟 𝑜𝑝𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 𝑐𝑢𝑟𝑟𝑒𝑛𝑡
𝑚𝑜𝑡𝑜𝑟 𝑐𝑢𝑟𝑟𝑒𝑛𝑡=
45
10.3= 4.37
Motor Controller System Circuitry at TRR
57
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller Power
Regulator
Power
Dissipater Models
PWM generator
Averaging Circuit
Summing amplifier
Timing chip
comparator
Relays Power
Systems and Management
Testing Design Project Overview
Engine: Main Tests
58
Test Stand Engine
Harness
Shaft
Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
Stock Engine Characterization: Completed Measured engine fuel flow rate, thrust, and frequency response over operational range Data used to validate MATLAB Engine Model and Rotor Dynamics Calculations, also provided baseline performance
Engine
Test Stand
LabView VI
Load Cell
Fuel Tank
DAQ Chassis
NI
92
05
NI
94
01
NI
92
34
ACC
Quantity Results
Max Speed 131,000 RPM
Max Speed During Startup
53,000 RPM
Thrust at Max Speed 19.8 lbs
Max Fuel Flow ~330 mL/min
Max Temperature 725°C
Full System Test
59
Test Stand Engine
Harness
Shaft Coupler
Motor &
Controller
Power Regulator
Power
Dissipater Models
Budget Subsystems Schedule Project Overview
Req # Requirement
1.1 The design solution shall not decrease stock thrust by more than 25%
1.2 The design solution shall not increase the thrust specific fuel consumption by more than 50%
1.3.1 The design solution must operate above 35,000 RPM, the bottom edge of the engine idle range.
2 Power generated shall be transmitted using 24 V DC current
3 The design solution shall be able to derive power from a JetCat P90-RXI engine.
3.1 The rotational energy of the engine shaft shall be converted into electrical energy via a generator.
4 The design solution, when integrated with the JetCat P90-RXI engine, shall interface with the test stand designed by the customer and the test stand available through CU.
4.1 The dimensions of the design solution and engine shall not exceed those shown below in Figure 2.4-1.
Facility: Boulder Bomb Squad Test Duration: 2.5 hours (1 hour travel & set-up, 30 min testing, 1 hour pack up & travel ) Equipment: Test Stand Assembly, Fuel Flow Sensor, Load Cell, Accelerometer, Design solution
Travel
60
Budget Subsystems Schedule Project Overview
• Currently $500 shortfall on travel for available team members ▫ Have funds to take 5 team members and Dr. Starkey
Item Cost Quantity Subtotal
Airfare $350 round trip 7 people $ 2,450.00
Hotel rooms $120 per night 2 nights, 3 people per room* $ 840.00
Per diem $56 per day 8 people, 3 days $ 1,176.00
Rental Car $125 per day for van 3 days $ 375.00
Total $4,841.00
Available $4,359.00
Itinerary Day Activity May 20 Travel to Dayton, OH. May 21 Demonstrate project May 22 Participate in group poster session and return
to Boulder, CO.
Travel Roster Name Role Dr. Ryan Starkey Team Advisor Matt McClain Project Manager Megan O’Sullivan Test Engineer Ben Woeste Safety Officer Jon Lumpkin Electrical Lead Kevin Wong System Engineer Eric James (Tenative) Software Lead
* Considerations have been made to give separate rooms to the men and women of the team; additionally the team’s advisor has been given his own single room
Load Cell for Full System Tests • Measurement
Specialties FX1901 Compression Load Cell
• Measurement Range: 0-10 lbf
• Excitation Voltage: 5 VDC
• Accuracy: 15% of span
61