Multidisciplinary Senior Design I
P10232 System Design
Review
Unmanned Aerial Vehicle - Airframe C
Daniel Graves – Project Manager
James Reepmeyer – Lead Engineer
Brian Smaszcz – Airframe Design Lead
Alex Funiciello – Airfoil Design Lead
Michael Hardbarger – Flight Control Systems
P10232 System Design Review
October 7, 2009
Page 2 of 19
Contents
P10232 Project Background .......................................................................................................................... 3
Project Summary ....................................................................................................................................... 3
Customer Needs........................................................................................................................................ 3
P09232 Senior Design Project ................................................................................................................... 3
Engineering Specifications ............................................................................................................................ 4
Sub-system specs .......................................................................................................................................... 4
Body Structure .......................................................................................................................................... 4
Airfoil/Wing ............................................................................................................................................... 4
Propulsion ................................................................................................................................................. 5
Landing gear .............................................................................................................................................. 5
Flight controls ........................................................................................................................................... 5
P10232 Concept Generation ......................................................................................................................... 6
Aircraft Style.............................................................................................................................................. 6
Airframe (key features) ............................................................................................................................. 6
Airfoil ......................................................................................................................................................... 7
Landing Gear ............................................................................................................................................. 7
Propulsion ................................................................................................................................................. 8
Flight Control Actuation Systems .............................................................................................................. 8
P10232 Concept Selection ............................................................................................................................ 9
Aircraft Type.............................................................................................................................................. 9
Airframe Design ........................................................................................................................................ 9
Tail Selection ........................................................................................................................................... 10
Airfoil Selection ....................................................................................................................................... 10
Landing Gear Selection ........................................................................................................................... 11
Propulsion Selection ............................................................................................................................... 12
Flight Control Actuation System ............................................................................................................. 14
P10232 Selected System Design ............................................................................................................. 15
Selected Concept ................................................................................................................................ 15
System Architecture (Physical) ............................................................................................................... 15
System Architecture (Electrical) .............................................................................................................. 16
Risk Management ....................................................................................................................................... 17
Important Links ........................................................................................................................................... 19
Bibliography ................................................................................................................................................ 19
P10232 System Design Review
October 7, 2009
Page 3 of 19
P10232 Project Background
Project Summary
The goal of the UAV Airframe C project is to provide an unmanned aerial platform used for an aerial
imaging system. The airframe must support the weight and interfaces for the designed imaging system.
The aircraft must be operated remotely and be a viable alternative to current aerial imaging methods.
This is a second generation airframe, expanding on the previously laid ground work established by the
P09232 UAV B Senior Design Project.
Customer Needs
 Airframe must be able to carry a fifteen pound payload
 Easy integration with measurement controls box and different aerial imaging systems
 Ability to remotely control aircraft and activate payload
 Ability for flight communication between aircraft and ground relay
 Aircraft provides twenty minutes of flight time for local area photography
 Aircraft has the potential to take off and land on site
 Easy assembly and disassembly of the aircraft for transportation
P09232 Senior Design Project
The Unmanned Aerial Vehicle concept began with last year’s Senior Design team. The design
used was a traditional monoplane powered by a two-stroke gasoline engine, with a small cambered flat
bottom airfoil. Shortly after take-off on the plane’s first flight the pilot lost control of the aircraft during
a banked turn. The plane proceeded to knife edge toward the ground, where the wings sheared off
shortly before impact. The failure was determined to be from the bending stress applied to the wings
during the banked turned. After analysis, it was concluded that the main fiberglass spar used to support
the wing was not properly selected to handle the loads experienced in flight. Additionally, the
deflection in the wing during flight reduced the effectiveness of the flight control surfaces thereby
greatly reducing the pilot’s control of the aircraft.
P10232 System Design Review
October 7, 2009
Page 4 of 19
Engineering Specifications
The following are the design specification for the Airframe C design.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
The aircraft shall have a maximum weight of 30 lbs without payload
The aircraft shall have a minimum flight ceiling of 1000 ft
The aircraft shall be able to sustain a flight of at least 50mph in calm conditions
The aircraft shall be capable of stable flight with a 15 lb payload
The aircraft shall utilize an open architecture payload interface
The aircraft shall provide a mechanical interface to the payload
The aircraft will provide a stable platform for the photographic instrument payload
The aircraft shall sustain steady flight in a controllable manner for at least 20 minutes
The aircraft shall be able to re-launch as soon as it has been re-fueled or re-charged
The aircraft shall be able to operate for at least 25 regular flights without needing routine
maintenance
The aircraft shall be able to take off under its own power from a 1000 ft runway
The aircraft shall be able to be transported in a motor vehicle when disassembled
The aircraft will be easy to assemble and disassemble by one person
The aircraft shall be able to navigate while on the ground
The aircraft should have similar flight characteristics to a trainer RC plane
Final cost must be less than the cost of renting a Cessna for a day (~$8000)
Sub-system specs
Body Structure






The structure shall support 15lbs of payload.
The structure shall have an accessible payload bay to contain the camera system.
The structure shall connect to the other components in a manor such that a single competent
person may assemble/disassemble the plane for transport.
The structure shall resist deformation under normal operation.
The structure shall house the planes power system, and provide a mount for the engine.
The structure shall be durable, enabling multiple flights without servicing.
Airfoil/Wing






The airfoil shall provide enough lift to carry the craft weight (up to 30lbs) plus the payload
weight (15lbs).
The airfoil shall minimize drag to enable the plane to fly for a minimum of 20 min.
The wing shall be able to be disassembled to a size such that they will be transportable by motor
vehicle.
The wing shall be structurally rigid and free of in flight flutter.
The wing shall contain control surfaces capable of maneuvering the plane in a manner similar to
a trainer style aircraft.
The wing planform area shall be designed such that wing loading is kept under 20 oz./ft2.
P10232 System Design Review
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
October 7, 2009
Page 5 of 19
The wing shall be structurally sound, allowing for repeatable 20 min. flights without
maintenance.
The wing shall resist deformation under loading allowing the pilot to remain in control of the
aircraft at all times.
Propulsion




The propulsion system shall provide uninterrupted, constant power for at least 20 min.
The propulsion system shall provide enough thrust to overcome drag and accelerate to flight
speed in the length of a 1000ft runway.
The propulsion system shall be clean and easy to maintain.
The propulsion system shall be reusable, only requiring refueling/recharging.
Landing gear



The landing gear shall allow the plane to be controllable on the ground (taxi and takeoff).
The landing gear shall protect the airframe, prop and payload during takeoff, landing, and
taxiing.
The landing gear shall provide minimal resistance on a grass runway, allowing the plane to reach
flight speed in less than 1000 ft.
Flight controls



The flight control system shall be able to actuate control surfaces, allowing the aircraft to be
flown like a basic trainer aircraft.
The control system shall maintain reliable control for at least 20 min.
The control system shall interface with the payload, triggering a camera system to take a
picture.
P10232 System Design Review
October 7, 2009
Page 6 of 19
P10232 Concept Generation
Aircraft Style








Monoplane – Traditional single winged aircraft design
Biplane – Two stacked wings; same lift half the wingspan
More than 2 wings - Same idea as a biplane, but 3 or more wings
Delta Wing – Plane With a delta shaped wing design
Flying wing – A plane consisting only of a wing structure; ie. No fuselage
Dirigible – A lighter than air aircraft such as a blimp or hot air balloon
Rocket – A rocket propelled craft
Helicopter – VTOL style craft with horizontal blades and no fixed airfoils. Can have one or more
main rotors
Due to the variety of these options it was necessary to narrow down the overall direction of our
research prior to generating sub-concepts. After some initial research it was clear we would be working
with a fixed-wing aircraft (thus disqualifying the dirigible, rocket, and helicopter options). For more on
the selection process please see the Concept Selection section.
Airframe (key features)













Canards
Motor / Engine placement
o Pusher – motor in back of the plane, pushes plane through the air
o Puller – motor on the front of the aircraft
o Multiple Power Sources
 Wing Mounted – motors attached to wings instead of built into the fuselage
 Twin Fuselage – one motor on the front of each fuselage
 Push and Pull – one motor on the front, one motor pushing from the back
Winglets – Small vertical stabilizers on the wing tips
Dual Fuselage – 2 fuselages running parallel, could hold cargo between them
Twin Boom – 2 extended booms connect the wing / fore-plane to the tail
Cambered (lifting) Tail
V-Tail – Two ‘slanted’ tails; fighter-jet style
H-Tail – Two vertical stabilizers / rudders on either end of the tail’s horizontal stabilizer
T-Tail – A traditional tail design but with the horizontal surface at the top of the vertical
stabilizer
Cruciform tail – Same as a T-tail but with the horizontal surface half-way up the vertical stabilizer
Tandem Wings – one bottom mount front wing and one top mount back wing
Swept Wings – Wings swept back fighter-jet style (supersonic wing design)
Folding Wings – Wings that fold for transportation / storage
P10232 System Design Review
October 7, 2009
Page 7 of 19
Airfoil













Thin wing – Airfoil with a low thickness to chord ratio.
Thick wing – Thickness to chord ratio of 12% or higher.
Symmetrical Wing – Symmetric about chord line
Cambered Wing – Curved airfoil to increase the nozzle and diffuser effects produced by the
wing.
Flat Bottomed Wing – A type of cambered airfoil with a flat, or nearly flat bottom surface.
Elliptical Wing – Theoretically ideal wing design with an elliptical planform shape.
Rectangular Wing – Rectangular planform area.
Tapered Wing – Wing with a longer chord at the root than at the tip. Trapezoidal planform
shape.
Additional Lifting Surfaces (i.e. Canards) – Adds lift, allowing for a smaller main wing.
Wing Mounting (top / center / bottom)
o Top – Wing is above the fuselage, above the centre of gravity.
o Middle – Wing mounted to side of fuselage.
o Bottom – Wing sits under the fuselage, below the planes centre of gravity.
Swept Wings – Wing tips are behind the wing’s root, swept back, decreasing the speed of the air
across the wing.
Dihedral – Wing with a slight upward angle, with the tip higher than the wing root.
Anhedral – Wing with a downward angle, with the tip lower than the wing root.
Landing Gear







Number of Wheels
o 2 wheels
o 3 wheels
o More wheels
Non-Wheeled Landing Gear
o Skis – intended for use on snow
o Pontoons – for use on lakes (which are found near all nuclear power plants)
o Skids – skid plates on the underside of the plane in place of landing gear
Retractable Landing Gear
Wheel Placement
o Wing Mounted – anchored to the wings instead of the fuselage
o Tricycle layout – font wheel turns, 2 wheels in the back
o ‘Conventional’ layout – aka tail dragger, rear wheel turns, 2 wheels in front
Launch Assist
o Car-top – released from the top of a moving vehicle (requires highway)
o Catapult – instant launch from some sort of a stand. Crossbow design?
Brakes – reduced stopping distance
‘Leave-behind’ landing gear – plane would liftoff from a sled with wheels, leaving the sled
behind
P10232 System Design Review
October 7, 2009
Propulsion




Power Source
o Electric Motor
 DC Brushless
 DC Brushed
 AC
o Fuel Powered
 2-Stroke (chainsaw / weed whacker)
 Glow / Nitro fuel
 Wankel
 4 –Stroke
 Diesel
o Rocket
 Rocket as main propulsion
 Rocket assisted launch
Exposed propeller
Ducted Fan
Multiple-Bladed propeller (>2 blades)
Flight Control Actuation Systems





Servo Motor
Stepper Motor
Pneumatic
Hydraulic
EHA (Electro Hydrostatic Actuator)
Page 8 of 19
P10232 System Design Review
October 7, 2009
Page 9 of 19
P10232 Concept Selection
Aircraft Type
Design
Cost (initial)
Cost
(sustainable)
Controllability
Transport
Flight Time
Payload
Airspeed
Total
Plane
0
0
Dirigible Helicopter
+
-0
0
0
0
0
0
0
0
---++
--7
0
-+
-6
Rocket
+
+
-*
+
*
-++
N/A
* Rocket fails to meet time and controllability specifications
As shown in the concept selection matrix, the fixed-wing airplane is considered the best option
for a successful design given the chosen criteria.
Airframe Design
Design
Cost (initial)
Piloting
Difficulty
Transport
Flight Time
Payload
Flexibility
Payload Weight
Airspeed
Total
Monoplane
0
0
Bi-plane
-
Delta
0
Flying
Wing
-+
Tandem
Wing
---
Split Body
--
Boom
Tail
-+
0
0
0
+
0
0
-++
-+
+
+
0
+
0
0
0
0
0
0
0
-3
0
+
-3
-+
-4
++
++
0
-2
+
-3
0
0
-1
The monoplane aircraft design was the selected concept to carry into detailed design. The
monoplane is the most commonly used airframe design in many applications, and to accommodate our
short design and build lead time, this will allow for the highest chance of success.
P10232 System Design Review
October 7, 2009
Page 10 of 19
Tail Selection
Stability
Design
Difficulty
Weight
Controllability
Drag
Flight
Envelope
Cost
Total
Cambered H-Tail
0
+
V-Tail
+
T-Tail
-
Crucifix Tail
-
0
0
0
0
+
+
-+
+
-+
0
-+
0
0
0
0
0
0
0
-1
+
-3
+
-3
We chose to use the Conventional tail configuration for UAV C. It will use a cambered horizontal
stabilizer which will create reverse lift and help us to keep the plane stable in flight with varying
payloads. This is the most commonly used tail configuration and also the most straight forward to design
since no additional strengthened connection points are required.
-
The twin tail or H-tail could work for our application but would increase the amount of design
work and components increasing weight and reducing low speed handling.
-
The T-tail would require an extremely robust tail piece in order to withstand the forces caused
by the increased moment forces on the connection point of the fuselage due to being located at
the top of the vertical stabilizer.
-
The V-tail is cutting edge technology and would require a more advanced control system in
order to experience the same control abilities of alternative configurations.
-
The cruciform is used to keep the tail out of the engines' wake or to avoid complex interference
drag. It requires a more robust tail design and for our small scale would not see any great
performance gains.
Airfoil Selection
Lift
Drag
Stall Angle
Stall Speed
Moment
Structure
Total
High CamberFlat Bottom
0
0
0
0
0
0
0
High Camber Under Cambered
+
+
+
+
2
Low
Camber
-+
+
0
-2
Reflex
-++
0
-3
Symmetric
-0
0
+
0
-2
P10232 System Design Review
October 7, 2009
Page 11 of 19
After critiquing last year’s design, the concept selected for the Airframe C’s airfoil is an undercambered thick airfoil design. The more aggressive cambered airfoil will produce more lift, decrease stall
speed, and decrease the required chord and wingspan compared to the UAV B; allowing the aircraft to
manage the same payload with a smaller wing span and planform. Final airfoil selection will be based on
XFOIL analysis. The wing will likely be rectangular in shape due to its ease of design and implementation.
The planform area will be selected based on wing loading.
Landing Gear Selection
Flight Drag
Ground Control
Nose Over
Ground Loop
Cost
Load Handling
Risk of Prop Damage
Cargo Protection
Operational Environment
Restrictions
Total
Conventional
0
0
0
0
0
0
0
0
Tricycle
+
0
++
+
-
Skid Plates
+
-+
+
--
Pontoon/Floats
-0
0
+
+
0
0
0
0
0
-5
--4
Skis
0
0
0
0
0
0
0
--3
As shown by concept selection matrix, either the conventional landing gear system or a tricycle
style landing gear system would be appropriate for our system design. After careful consideration, the
conventional style landing gear system was chosen as the concept to move forward with because it
naturally lends itself to a better angle of attack on the ground, creates less drag, and better protects
vital aircraft components in case of failure.
P10232 System Design Review
October 7, 2009
Page 12 of 19
Propulsion Selection
Initial Cost
Running Cost
Controllability
Power
Weight
Design Flexibility
Fuel/Battery Consumption
20 min Flight Time
Vibration
Reliability
Maintenance
Total
Glow/Nitro
*
0
0
*
0
0
0
*
0
0
N/A
Gasoline
0
0
0
0
0
0
0
0
0
0
0
0
Electric
0
+
+
--++
0
0
+
++
++
5
*Glow engines of the size needed are not readily available
Gasoline Motor Research
Name
XY 50cc
Turnigy
50
DLE
RCG
Fuji BT64
FUJI 86
Fuji 43
3W55iUS
Total
Weight
with
Fuel
kg
2.26
Engine
Price
$
238
Price to
Power
Ratio
$/W
0.07
Price to
Weight
Ratio
$/kg
105.38
Power
to
Weight
Ratio
W/kg
1550
Volume
CC
50
Power
W
3502
Engine
Weight
kg
1.62
50
55
50
4103
4103
3879
1.38
1.35
1.36
2.02
1.99
2
240
319
209
0.06
0.08
0.05
118.9
160.42
104.58
2033
2063
1941
64
86
43
4252
5222
3133
2.28
3.2
1.8
2.92
3.84
2.44
450
800
450
0.11
0.15
0.14
154.19
208.41
184.54
1457
1360
1285
55
4476
1.9
2.54
625
0.14
246.21
1763
Electric Motor Research
Name
Rim Fire
65cc
Rim Fire
50cc
Turnigy
Aero
Drive XP
63-74
Turnigy
Aero
Drive XP
63-64
Exceed RC
HXT 63-74
Rim Fire
1.6
RPM/
V
rmp/v
Volts
V
Constant Constant
Current
Power
A
W
160
55.5
135
230
55.5
170
Required
Number
Number
of
of Cells
Battery
Needed
Packs
#
#
Total
Weight
of
Battery
Payload
kg
Total
Weight
kg
Total
Cost
$
Weight
To Cost
Ratio
$/kg
Power/
Weight
W/kg
Weight
kg
Cost
$
7500
1.4742
270
15
9
6.71
8.19
810
98.94
1117.26
110
5000
1.2474
250
15
8
5.97
7.21
720
99.8
837.95
37
90
3250
0.8391
60
10
6
4.48
5.31
540
101.61
726.22
230
245
200
37
33.3
37
90
60
50
3150
2700
2400
0.6889
0.6464
0.7002
60
50
60
10
9
10
6
4
4
4.48
2.86
2.86
5.16
3.51
3.56
540
330
340
104.57
94.12
95.5
703.87
944.06
839.17
250
44.4
45
1665
0.635
140
12
3
2.14
2.78
210
75.54
776.23
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝐶𝑒𝑙𝑙 𝑃𝑎𝑐𝑘𝑠 𝑁𝑒𝑒𝑑𝑒𝑑 = 1000 × [
𝐶𝑢𝑟𝑟𝑒𝑛𝑡 𝐷𝑟𝑎𝑤(𝐴) × 𝐹𝑙𝑖𝑔ℎ𝑡 𝑇𝑖𝑚𝑒 (ℎ𝑜𝑢𝑟𝑠)
]
𝐵𝑎𝑡𝑡𝑒𝑟𝑦 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦 (𝑚𝐴ℎ)
Our research into the differences between the gasoline engines vs. the electric motors have not yet lead us to any conclusive results. More
research and expert opinions will be sought before any decisions are finalized.
Flight Control Actuation System
Difficulty of Design
Complexity
Quick Connect
compatible
Weight
Power output
maintenance
cost (initial)
cost (sustained)
Total
Electric
(servo)
0
0
0
0
0
0
0
0
0
Electric
(stepper) Pneumatic
-0
0
0
-6
-+
0
0
-5
Hydraulic
--++
-7
EHA
--0
0
++
--6
After considering the commonly used alternatives we concluded an off-the-shelf electric servo
system would work best. Furthermore we have a (hopefully) functional servo system from Airframe B.
This hardware will need to be analyzed and tested prior to use to make sure it matches our needs.
Successful utilization of this hardware will help reduce the overall cost of our build.
P10232 System Design Review
October 7, 2009
Page 15 of 19
P10232 Selected System Design
Selected Concept
The selected system design for the P10232 project will be an electrically powered monoplane
with a standard cambered tail section. The airfoil will be under-cambered to provide more lift and
reduce the wingspan. The wing will be rectangular for its ease of design and will be top-mounted to the
airframe. A conventional landing gear system will be used to assist in short take-off and for its low drag
properties.
System Architecture (Physical)
P10232 System Design Review
System Architecture (Electrical)
October 7, 2009
Page 16 of 19
Risk Management
ID
Risk Item
Effect
Cause
Likelihood
Severity
Importance
Action to Minimize Risk
Owner
9
Design aircraft and associated
tests correctly. Study weather
for optimal test conditions
Lead
Engineer
6
Create proper schedules with
an appropriate buffer time
between dependent actions
Team Lead
Entire
Team and
Lead
Engineer
1
Flight Test
Failure
Team fails to meet project
deliverable
Poor aircraft
design, pilot
error, etc.
2
Meeting
Project
Deadlines
Project will run behind
schedule, or project
deliverables are not met
Poor planning
and poor
execution
3
Component
Redesign
Forced project redesign
can force the project to run
over deadlines
Aircraft was not
designed with
proper
components
1
3
3
Smart aircraft design with
proper backing analysis.
Compliance with subsystem
interface designs.
4
H1N1/Illness
Team members can fall
behind in work
Germs
3
1
3
Proper cleanliness and Hygiene
Entire
Team
5
Build Time
Runs Over
Delay in meeting project
deliverable, flight testing
does not run on schedule
2
2
4
Begin build phase early and
maintain positive team morale
Team Lead
6
Component
Testing Failure
Delay in project deliverable
or testing schedule
Poor scheduling
and poor work
habits
Faulty
component or
poor system
design
1
2
2
Test parts early and properly
design all critical systems
Entire
Team
7
Miscellaneous
Damages/Theft
Loss of progress and time
Negligence
1
3
3
Ensure all parts are properly
stored and secured
Entire
Team
3
3
3
2
ID
Risk Item
Effect
Cause
Budget
Increase
8 Needed
Unable to purchase critical
parts needed for aircraft
design and build
Budget
Driven
9 Redesign
Team will have to redesign
aircraft systems, increasing
time needed for
completion
Expensive
design or over
design
Improper
knowledge of
budget
constraints or
funding
restricted
Parts were not
ordered far
enough in
advance
Part Lead
10 Time
Team
Member
11 Injury
Parts required for
assembly delay build
progress
Critical Data
12 Loss
Team member can fall
behind in work resulting in
a progress delay
Component re-design or
analysis will need to be
repeated
Winter Break
13 Start Up
Ramp up time for project
build is longer due to
winter break
Multiple
Hard drive
failure or lost
flash drive
The break
between Fall
and Spring
quarters
Likelihood Severity Importance
Action to Minimize Risk
Owner
2
Have budget clearly defined
and avoid expensive
2 components where possible .
Team Lead
and Lead
Engineer
3
Have budget clearly defined
and avoid expensive
3 components where possible .
Team Lead
and Lead
Engineer
1
Order parts at the end of MSDI
and make sure all parts are
2 ordered
Team Lead
and Lead
Engineer
1
2
Every team member acts in a
responsible manner ensure
Entire
2 work is done in a timely manner Team
1
2
All documents are backed up
2 on EDGE
Entire
Team
2
Continue work and project
updates during the winter
2 quarter
Entire
Team
1
1
2
1
Important Links
P10232 Project Website - https://edge.rit.edu/content/P10232/public/Home
P09232 Project Website - https://edge.rit.edu/content/P09232/public/Home
Bibliography
Reyes, Carlos. Model Airplane Design Made Easy. Albuquerque: RCadvisor, 2009.
Ulrich, Karl T.; Eppinger, Steven D. Product Design and Development (4th ed.). New York, NY: McGrawHill, 2008.