Assignment title: Information
ENGG1200 Engineering Modelling and
Problem Solving
Semester 2, 2016
Document 3: Project A
Glider with Flight Data Recorder
An unmanned aerial vehicle launch rig (Insitu, 2014)
Project
Leaders:
Dr Brendan Chen (Aerospace Engineer)
Mr David Cusack (Mechanical Engineer)
Mr Kianoosh Naveh (Mechatronics Engineer)
Dr Juan Torres (Mechanical Engineer)Doc I.D: 2016-ENGG1200-PA
Version: V2
Date: 26/07/2016
Project A Semester 2 2016 2/14
The Brief
This document is a client-specified brief. Supplementary information will be communicated through
the Problem Solving Sessions and announced via Blackboard. If your design team requires further
information or detail, please contact your project leader.
Roles
Work submitted as part of this course must be designed and built entirely by engineering students
enrolled in ENGG1200, Semester 2, 2016. Project leaders, tutors and university technicians can be
used as consultants for specific information. Your team is required to engage in clarifying any or all
of these specifications to deliver the project at the tender competition, being at Demonstration in
Week 13.
Safety
Part of this course requires you to manufacture and assemble components yourselves. Since this is a
university project, the university has a duty of care for your safety. You are therefore required to
complete this work in the ABB Student Technology Centre (ABB STC) where university staff can
supervise your work.
No toxic or dangerous materials will be allowed. The determination of safe materials will be made by
comparison to the Hazardous Substances List at http://www.uq.edu.au/ohs/hazardous-substances
(The University of Queensland, 2014). This check must be submitted as part of Build Risk
Assessment in the Preliminary Memo (due Week 4) and is required for approval prior to
construction.Doc I.D: 2016-ENGG1200-PA
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TABLE OF CONTENTS
Introduction......................................................................................................................................4
1.1 Overview....................................................................................................................................4
1.2 Project Scope.............................................................................................................................5
Design Specifications........................................................................................................................5
2.1 System Overview.......................................................................................................................5
2.2 Launch Rig .................................................................................................................................6
2.3 Tensile Member.........................................................................................................................8
2.4 Retraction Force ........................................................................................................................8
2.5 Launch Sequence.......................................................................................................................8
2.6 Flight Data Recorder..................................................................................................................9
2.7 Design Constraints...................................................................................................................10
Models and Simulations .................................................................................................................11
3.1 Overview..................................................................................................................................11
3.2 Structural Modelling (CREO) ...................................................................................................11
3.3 Behavioural Modelling (MATLAB/Simulink, ANSYS)................................................................13
Manufacturing and Testing ............................................................................................................13
Prototype Cost................................................................................................................................13
Frequently Asked Questions ..........................................................................................................14
References......................................................................................................................................14Doc I.D: 2016-ENGG1200-PA
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INTRODUCTION
1.1 Overview
Micro Aerial Vehicles (MAVs) are often utilised as aerially deployed solutions for information
gathering over inaccessible terrain. MAVs require robust and portable launch systems that can
easily be depolyed in the field. Systems such as the one used by the ScanEagle Unmanned Aircraft
System (UAS) (shown on the cover page) have a demonstrated record for reliability and integrity.
Boeing Research and Technology Australia is seeking bids for the detailed design, manufacture and
demonstration of a proof of concept model for a gliding MAV that is suitable for launching from such
a rig. Your project team has been assembled to prepare a tender bid on behalf of your company.
The aim of this project is to design, build and demonstrate a gliding model aircraft that carries a
flight data recorder (FDR) as its payload. To achieve this each team will have to complete the tasks
shown in Table 1.
Table 1 Outline of tasks
Doc 1 pg 2 ref. Task
DSB1, DSB2, Design, manufacture and demonstrate a gliding model aircraft
MA Design a component using Computer Aided Design (CAD) software, and submit
a CAD file suitable for manufacturing
MB1 Use a basic Computational Fluid Dynamics (CFD) simulation to find coefficients
of lift and drag
MB2 Simulate the model aircraft's flight path in MATLAB/Simulink software
DSB1, DSB2 Obtain coefficients of lift and drag experimentally from a wind tunnel test
DSB3 Assemble and solder electronic components
DSB3 Write code for a microprocessor to read data from an accelerometer and
illuminate LED's
DSB3 Manufacture a thermo-formed electronics enclosure
DSB4 Attach strain gauges to a tensile member and then use strain data to calculate
force
In completing this project your team will need to demonstrate skills often attributed to:
mechanical engineers (structural design, manufacturing, assembly, modelling of aircraft
designs for flight profiling and performance simulation);
aeronautical engineers (wing profile design, flight profiling, and performance simulation);
electrical/ mechatronic engineers (electrical component assembly, soldering and
programming); and
software engineers (programming).Doc I.D: 2016-ENGG1200-PA
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1.2 Project Scope
Your scope of work for this project will include:
Design, manufacture and demonstrate a proof of concept model glider, including wings,
fuselage and tail system, to be deployed from the university's launch rig;
Assemble, program and demonstrate an FDR system;
Design quick release plate for mounting aircraft and generate a TAP file for its manufacture;
Fit strain gauges to a tensile member that will enable measurement of the launch retraction
strain (LSV); and
Calculations to convert LSV to the Launch Retraction Distance (LRD).
The project will be documented through:
a preliminary memo including project management details (e.g. Gantt chart, risk assessment
etc.), and
a final report.
The university will provide:
the launch rig including control system;
FDR kit components;
manufacturing equipment for each team's CAD designed component;
a tensile member, strain gauges and instrumentation to read strain from strain gauges.
DESIGN SPECIFICATIONS
2.1 System Overview
Figure 1 shows the main components for this project and their relationships. Each team will design
and build a model aircraft that will be launched from the client's rig. Prior to launch, a tensile
member fitted with strain gauges will be used to measure the launch retraction force. The aircraft
will be launched horizontally and glide (unpowered) until it lands on the ground. The aircraft should
be designed to maximise flight duration and distance. The FDR is carried on board the aircraft
throughout the flight. The FDR starts timing the flight when it senses the launch acceleration, and
stops timing when it senses the landing deceleration. Upon landing it displays the measured flight
duration on 5 Light Emitting Diodes (LEDs) using binary code.
During weeks 7, 8 & 9 your team will spilt into sub-teams to complete the tasks listed in the coloured
boxes at the top of Figure 1.Doc I.D: 2016-ENGG1200-PA
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Figure 1. System diagram
2.2 Launch Rig
The client has an existing launch rig as shown in Figure 2 that you will use to launch your aircraft.
The launch rig essentially functions as a large automated slingshot. The rig has the following
characteristics:
1. Launch point is 1725 mm above ground level.
2. Maximum retraction distance = 2.5 m.
3. Launch rail is fixed in a horizontal position.
4. The part of the rig that supports your aircraft and travels with it during launch is called the
sled. The top of the sled has a mounting flange where you will mount your quick release
plate. Details of the quick release plate are in section 3.2.
The launch rig has two elastic cords that provide thrust to accelerate the model aircraft during
launch. Each of these cords wraps around its respective pulley at the front of the rig as shown in
Figure 3. Since each cord wraps 180o around its pulley, the reaction force required to hold the
pulleys in place is twice the retraction force.
The pulleys are mounted on a lever arm 400 mm above the lever arm pivot point as shown in Figure
3. The grip that holds one end of the tensile member is also mounted on the same lever arm 71.5
mm above the pivot point. The ratio of these distances provides a mechanical advantage of 5.6, so
the force in the tensile member is 5.6 times the force at the top of the lever arm.
Flight Profile
Acceleration
Drag Lift
Structural Sub-Team:
• Build CAD (CREO) model
• Design quick release plate
• Creates toolpath file (.tap) to
manufacture quick release
plate
Behavioural Sub-Team:
• ANSYS CFD simulation to find lift
and drag coefficients
• Simulink model of flight profile
Microprocessor
calculates flight
duration
Accelerometer
detects launch
and landing
Whole Team:
• Designs and manufactures aircraft
• Builds and programs electronic kit
• Calculates strain at launch distance
• Attaches Strain Gauge to Tensile Member
Launch Retraction Distance
Launch acceleration starts
Flight Data Recorder (FDR)
Launch rig control
system retracts
specified distance
Strain gauges mounted
on Tensile Member
Calculatestrain at launch retraction distance as
a function of Young's Modulus and tensile
member geometry
Strain, ε
PCB
Thermo-formed
electronics enclosure
Landing
deceleration
stops FDR
Force
Flight Data Recorder
LEDs display flight
duration in binary codeDoc I.D: 2016-ENGG1200-PA
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Figure 2. Launch rig
For safety the rig power supply will be disabled while you load your quick release plate and aircraft
model onto the rig. Only the supervising tutor may operate the rig. There will always be a safety
zone in effect around the rig while it is operating.
Figure 3: Front end assembly detail view
Model position
Elastic Cord Pulleys
Pivot
Tensile Member
71.5
D1
400
Elastic Cord Tension
Reaction Force
Lever ArmDoc I.D: 2016-ENGG1200-PA
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2.3 Tensile Member
The tensile member shown in Figure 4 is a small component that you will mount in the launch rig to
measure retraction force. Your team will be given a tensile member made of either aluminium or
carbon steel. During the semester, some members of your team will attend a lab session where they
will attach strain gauges to the tensile member.
Figure 4: Tensile member dimensions
The tensile member will have a nominal thickness of 3, 4, or 5 mm and have a gauge width of
between 11.5 and 16 mm. You will have to measure your team's tensile member's gauge width and
thickness. Using these dimensions and the material's Young's Modulus you will calculate the
relationship between strain and applied tensile force. You will have the opportunity to check this
relationship using a test unit available in the ABB STC. On Demo Day your team will specify your LRD
and the corresponding LSV. Your aircraft will be launched from the specified LRD, and you will be
marked on the accuracy of your LSV.
2.4 Retraction Force
As the launch rig retracts in preparation for launching, the force in the elastic cords increases. Figure
5 shows the relationship between retraction force and retraction distance. Note that the
relationship is not linear, and that it follows a different curve during retraction and extension. Over
the course of the semester, you will learn skills to build mathematical models using this data.
2.5 Launch Sequence
During launch these steps will be followed:
1. The system will initially be at rest with minimal tension in the elastic cords and no power to
the retraction motor.
2. Aircraft is mounted on quick release plate. Tensile member is inserted into grips. Control
system is attached to strain gauge wires. LRD and LSV are uploaded to control system.
3. Power connected to control system.
4. Rig motor retracts sled/ aircraft. Tension, therefore strain, in tensile member increases
during retraction.
5. When distance reaches LRD retraction ceases.
6. Tutors record the LSV at the LRD.Doc I.D: 2016-ENGG1200-PA
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7. UQ staff conduct safety check.
8. UQ staff manually trigger launch.
9. Sled disengages from carriage. Elastic cord tension accelerates sled and aircraft forward.
10. Sled stops at end of rail, while aircraft disengages from quick release plate and flight
commences.
Figure 5: Retraction force to distance relationship
2.6 Flight Data Recorder
The model aircraft will carry a payload consisting of a FDR shown schematically in Figure 6. The
purpose of a real FDR is to record flight data and to transmit this information in the event of a crash
landing to make finding the crash site easier. Such a FDR would require many functions, have
significant mass and occupy significant volume. In this project you have limited payload mass and
volume, so the only functions required of your FDR will be:
1. To recording flight duration (in seconds); and
2. To display this information after landing using binary code on the LEDs.
To manufacture your FDR your team will be issued a FDR kit containing electronic components
including:
A programmable microprocessor (Arduino Mini);
A programmer chip;
A micro USB cable;
A battery;
An accelerometer;
A push button;
A Printed Circuit Board (PCB);
Five resistors; and
Five Light Emitting Diodes (LEDs).
0
10
20
30
40
50
60
70
80
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200
Force (N)
Distance (mm)
Project A Retraction Force vs Distance
Extending
RelaxingDoc I.D: 2016-ENGG1200-PA
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Figure 6: FDR components
Your team will solder the resistors and LEDs onto the PCB and complete the FDR assembly.
The accelerometer will be the sensor that detects your aircraft's stages of flight including:
launch (high positive acceleration);
flight (relatively low acceleration); and
landing (high negative acceleration).
Your team will write code for the microprocessor to detect the launch and landing accelerations
while filtering out irrelevant signals during flight. When your aircraft detects that it has landed it will
illuminate the LED's in a binary pattern to indicate flight duration in seconds. For example, if the
flight duration is 10 s, your LEDs should show the binary code '01010', where each '1' represents an
illuminated LED and each '0' represents an unilluminated LED. The maximum number that can be
expressed with five binary digits is 31 ('11111'). If your flight duration is 31 s or greater the display
should read '11111'. You will receive marks for the accuracy of the indicated flight time.
The push button serves two purposes:
Short push action (<5 s): Annunciation tests where all LEDs are illuminated to indicate
correct functioning.
Long push action (>5 s): Hard reset the FDR system (i.e. revert to the initialisation state)
FDR electronic kits will be handed out at the electronic lab sessions. These sessions are not listed on
the official UQ timetable. The location and schedule for these sessions will be advertised in advance.
You will be required to book a session. Tutors will be available to help you with soldering, assembly
and programming at these sessions, but after these sessions you will have to rely on the online
resources and online staff support.
During the semester you will manufacture an enclosure for your FDR using the thermo-forming
process. You will learn more about this process during your materials sessions.
2.7 Design Constraints
The intent of this project is to design and build an unpowered model aircraft that will be useful for
gathering information in real life situations. Therefore, your aircraft must have:
a wingspan of no greater than 600 mm;
a length of no greater than 600 mm;
accelerometer microprocessor battery
Push button
PCB
programmer computer
vacuum formed
electronics
enclosureDoc I.D: 2016-ENGG1200-PA
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a height of no greater than 300 mm;
a mass no greater than 250 g;
a total cost no greater than AU$100; and
no stored energy of any form (battery, pre-loaded spring, etc.) other than that required for
the flight data recorder.
Any model that does not meet these constraints, or is deemed by any one project leader to be
unsafe, will not be tested and receive ZERO marks for the Performance criteria on Demo Day. Speak
to your project leader if you are unsure about whether your design satisfies all the constraints.
While your team has freedom to choose any materials for the model, bear in mind that there is a
materials component to this course, and you will be expected to justify your material selection in the
final report.
MODELS AND SIMULATIONS
3.1 Overview
During Weeks 7, 8 and 9 your team will split into two sub-teams. One sub-team will attend
structural modelling sessions where they will learn to use the CREO 3.0 CAD package. The other subteam will attend behavioural modelling sessions where they will learn to use MATLAB/Simulink and
ANSYS to simulate the behaviour of your aircraft design during launch and flight.
Your team must first generate a design concept and model this design in CREO. The CREO model can
then be opened in ANSYS, which is a CFD package that simulates air flowing over the aircraft
allowing you to calculate the lift and drag coefficients of your design. These coefficients can then be
entered into your Simulink model to calculate the theoretical flight duration and distance. The
theoretical flight duration and distance can be compared with the actual flight duration and distance
of the aircraft, while the lift and drag coefficients can be compared with the experimental values
obtained from wind tunnel tests. Both the simulation results and experimental results should be
used to improve your model to achieve optimal performance.
No prior CREO, ANSYS, or MATLAB/Simulink experience is required or expected prior to starting
ENGG1200, but all students are required to complete pre-work prior to attending their Week 7
session. Details of the pre-work are available on Blackboard. Pre-work should be started as early as
possible (well before Week 7) to maximise the benefit to your team. Students are expected to
attend either the structural or behavioural modelling sessions. Please see your project leader if you
are interested in attending both.
3.2 Structural Modelling (CREO)
The two main tasks of the structural modelling sub-team are:
1. to create a 3D CAD model of the aircraft fuselage and wing; and
2. to create a tool path file for the manufacture of the team's quick release plate.
The structural sub-team will create a simple model of an aircraft fuselage and wing as part of their
pre-work leading up to the first CAD session in Week 7. The instructions for this pre-work will be
available on Blackboard. This model must be completed before Week 7 so that it can be given to theDoc I.D: 2016-ENGG1200-PA
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behavioural modelling sub-team who will need it at the start of their Week 7 behavioural modelling
session. Throughout the project the structural sub-team will continually improve and update the
aircraft model as the behavioural sub-team provides feedback on its performance.
The quick release plate will be the interface between your aircraft and the launch rig. The lower
section of the quick release plate must be as shown in Figure 7 so that it can mount correctly on the
launch rig and in the wind tunnel. Your team will design the upper section (shown shaded) of the
quick release plate to interface with the bottom of your aircraft. That is, your aircraft has to remain
attached to the top of the quick release plate during launch acceleration, but release cleanly from
the quick release plate when the sled stops.
Figure 7: Quick release plate
During your structural modelling sessions you will generate a tool path file (.TAP) that a CNC milling
machine will follow to manufacture your quick release plate. The TAP file must be submitted
electronically during Week 9. Your quick release plate will be manufactured during the midsemester break and be available for collection from the ABB STC during week 10.
Before submitting your TAP file please note that:
The maximum allowed machining time is 2 h/team;
A JPEG format VERICUT screenshot (a CNC simulation software tool) showing the machining
axis must be submitted along with the TAP file; and
The files you submit must be named as below:
o (Project)_(Student Number).tap (ie, ProjectA_S4123456.tap)
o (Project)_(Student Number).jpg (ie. ProjectA_S4123456.jpg)
The above requirements will be covered in more detail during the CREO training sessions. Noncompliant submissions will need to be resubmitted. Delays caused by resubmitting will affect your
team's progress and may affect your team's marks for the Model Test. CAD tutorials will be held in
the timeslot previously used for your materials sessions.
All your CAD design work will be done using the CREO CAD package. If you try to use other software
we cannot guarantee that your aircraft CAD model will be suitable for use in ANSYS simulation. Also,
other software will be VERY unlikely to successfully generate a tool path. UQ staff are not trained in
use of other CAD software packages and will be unable to offer advice.Doc I.D: 2016-ENGG1200-PA
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3.3 Behavioural Modelling (MATLAB/Simulink, ANSYS)
The behavioural sub-team will create a simple Simulink model of projectile motion as part of their
pre-work leading up to the first behavioural modelling session in Week 7. The instructions for this
pre-work will be available on Blackboard. The pre-work must be completed before Week 7 for
submission at the start of the first behavioural modelling session. This model will be the starting
point for the full Simulink simulation of the aircraft's launch, flight and landing that you will develop
over the remainder of the semester.
During Weeks 7, 8 and 9 the behavioural modelling sub-team will use both ANSYS and Simulink to
model the aircraft's behaviour during launch and flight. Firstly, the CAD model of the aircraft
(created by the structural sub-team) will be loaded into ANSYS to calculate the coefficient of lift (CL)
and the coefficient of drag (CD). Then the behavioural sub-team will build a MATLAB (Simulink)
model that uses these values of CL and CD to model the behaviour of the aircraft during flight. The
outputs from the Simulink model will be the aircraft's acceleration profile, flight distance and flight
duration.
The behavioural sub-team is expected to continue using the Simulink and ANSYS models after Week
9 to identify ways that the aircraft design can be improved, and to pass this information on to the
structural modelling team. The behavioural sub-team must also inform the FDR sub-team of the
expected acceleration profile during the launch, glide and land sequence.
MANUFACTURING AND TESTING
The ABB STC will be available from Weeks 9 to 12, for teams to build their model aircraft. Booking is
required and will be available from Week 8. Entry requirements for the ABB STC are available at
https://learn.uq.edu.au/webapps/blackboard/content/listContentEditable.jsp?content_id=_710101
_1&course_id=_19673_1
The launch rig will be made available for viewing during one of the Problem Solving Sessions (PSS) in
Weeks 1 to 6. A YouTube video (not publicly available) that shows last year's Project A Demo Day is
available at https://goo.gl/q4FBCn.
PROTOTYPE COST
The final cost of your build may not exceed $100. Your team will need to bring a costed bill of
materials during Demo Day as a part of your assessment, and include it as a part of your final report.
If a component used for your aircraft was obtained for free you must provide a quote for an
Australian market price. Any item that has been left out of the cost during demo week will be added
at standard market price.Doc I.D: 2016-ENGG1200-PA
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FREQUENTLY ASKED QUESTIONS
Common project-specific questions and answers are provided in Table 2 below.
Table 2: FAQs
Item # Question Answer
1
Can I get multiple parts
manufactured using the
University's CNC machines?
No. We only have capacity to manufacture one part per
team. Please purchase materials and use the tools in
the ABB STC to manufacture the rest yourselves.
2
Are we allowed to make
absolutely any
shape/design we want as
long as we satisfy the
design specifications and
believe it will work the
best?
Your design has to reflect the design intent of the
project. While we encourage creativity, we will not
accept designs such as hot air balloons, boomerangs or
arrows that may technically meet the size limitations,
but are obviously not viable solutions for gathering data
over inaccessible terrain. If you intend to design
something not easily recognisable as a conventional
aircraft, then consult your project leader.
3
Are we just aiming to
launch a projectile as far as
possible?
No. Flight duration is worth more marks than flight
distance as described in Document 2.
4
Can we purchase a model
aircraft and modify it to
suit our purposes?
You may use modified aircraft parts, but you are
required to manufacture the lift surfaces (wings) of your
aircraft.
5
If every team finds that one
wing profile provides the
best CL and CD will we all
get the same score on
Demo Day?
No. Aircraft design has far more variables than wing
profile. You will also have to consider wing placement,
fuselage design (to accommodate electronics),
mounting point for launching, wing angle, wing taper…
REFERENCES
HBM. (n.d.). Strain Gauges & Accessories for Strain Measurement. Retrieved July 16, 2014, from
HBM Australia: http://www.hbm.com/en/menu/products/strain-gages-accessories/
Horowitz, P., & Hill, W. (1989). The art of electronics. Cambridge: Cambridge University Press.
The University of Queensland. (2014). Hazardous Substances. Retrieved July 16, 2014, from The
University of Queensland: http://www.uq.edu.au/ohs/hazardous-substances