PRELIMINARY DESIGN REVIEW

PRELIMINARY DESIGN REVIEW
Team Scout: Austin Anderson, Geoff Inge, Ethan Long, Gavin Montgomery,
Mark Onorato, Suresh Ratnam, Eddy Scott, Tyler Shea, Marcell Smalley
Scout Preliminary Design Review 2013
October 15, 2013
1
OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
October 15, 2013
2
BACKGROUND AND PURPOSE
• Autonomous search and rescue multicopter
• Capable of exploring dangerous urban environments
• Reduce risk to human life
• Map the environment
• Navigating through doorways is a critical capability
Scout Preliminary Design Review 2013
October 15, 2013
3
OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Sensors
7) Single Board Computer
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
October 15, 2013
4
REQUIREMENTS
1.1 The sensor suite shall measure its relative position to the wall/doorframe/ground while it is 0-1 m from the wall at an
altitude of 1-2 m
1.1.1 The sensor suite relative position measurement shall be accurate to within ±3 cm
1.2 The sensor suite shall mechanically integrate with the multicopter to form Scout
1.2.1 The sensor suite shall be less than the 1.5 kg maximum payload capacity of the multicopter
1.2.2 Scout shall have an endurance of 10 minutes
1.2.3 The sensor suite shall utilize regulated power from an additional battery
1.3 The sensor suite and control system shall communicate and send proper signals to control the multicopter
1.3.1
The control system shall actuate the motors of the multicopter to achieve the desired motion
1.4 Scout shall maintain controlled flight with error no greater than ±6 cm from its desired position
1.4.1 Scout shall be capable of hover, with a designated orientation, at altitude of 1-2 m
1.4.2 Scout shall be capable of maneuvering at a speed between 0.2 – 2 m/s
1.5 Scout shall be capable of comparing its onboard data with the RECUV indoor flying lab
1.5.1 Scout shall be capable of mounting IR trackers, used by the flying lab
1.5.2 Scout’s data shall be stored I such a way that it can be compared to the flying lab’s data
Scout Preliminary Design Review 2013
October 15, 2013
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
October 15, 2013
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PROJECT OBJECTIVES
• Level 1 Objective: Sensing
• Design a sensor suite capable of integrating with a multicopter platform
• Sensor Suite shall measure relative position* of targeted objects with an error of no more
± 3cm when located 0-1 m from the targeted object.
• Level 2 Objective: Motion
• The control system must control the relative position of the platform to ± 6 cm of a
commanded position
• Scout must maintain controlled hover
• Scout must achieve controlled dynamic motion
• Level 3 Objective: Doorway Searching & Maneuvering
• Search for doorway, measuring 0.9m X 2.0m, through lateral movement along wall
• Navigate and maneuver through a doorway upon detection
*from the sensor to a specified point on the doorway
Scout Preliminary Design Review 2013
October 15, 2013
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Top View
CONCEPT OF OPERATIONS
Power up and maintain
hover at 1-2 m above the
ground.
Wall
Doorway
Floor
Begin Searching for
doorway 0-1 m away from
wall
Side View
Doorway
Wall
Floor
October 15, 2013
Scout Preliminary Design Review 2013
Determine when a 0.9 m
by 2 m doorway is present
and stop searching.
Maneuver through the
doorway and cease
operation.
8
FUNCTIONAL BLOCK DIAGRAM
Scout Preliminary Design Review 2013
October 15, 2013
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BASELINE DESIGN
2D Laser mounted on
upper mounting facing
platform's path
Multicopter:
Arducopter RTF X8
Control:
APM 2.6 running Arducopter
autopilot
Sensor:
Hokuyo URG-04LX-UG01
APM mounted
directly on
multicopter
upper surface
Sensor:
MaxBotics MB1043
Ultrasound placed on
lower mounting .
Faces floor
CDH mounted on
lower mounting.
Facing upward
Command/Data Handling:
BeagleBone Black
October 15, 2013
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SCOUT INTERFACE SUMMARY
BeagleBone Black
Autonomously
Processes
Processes
position
input flies
from
and
Acquires
position
Acquires vertical
lateral position
through
thedata
doorway
using
telemetry
Beaglebone
and
andsends
sends
measurement
APM
voltage
commands
“stick”
commands
command
to
motors
to APM
Ultrasonic
Sensor
(MB1043)
Laser Sensor
(URG-04LXUG01 )
Sensor Data
Telemetry Data
Logic Command
AutoPilot Command
GPIO, RS 232, Digital
USB, MAVLink, Digital
3DR RTF X8
Scout Preliminary Design Review 2013
APM 2.6 Autopilot
Voltage Command
October 15, 2013
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IDENTIFICATION OF CRITICAL PROJECT
ELEMENTS
Critical Purchases
• Multicopter Selection
• Dictates mass budget/payload capacity
• Determines mounting locations
• Imposes restrictions on the autopilot system used
• Autopilot Selection
• Imposes limitations on what sensors can be used
• Control capabilities of the multicopter
• Sensor Selection
• Dictates communication protocols (ex: RS232)
• Imposes limitations on how quickly position can be established
Scout Preliminary Design Review 2013
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Design Challenges
• Sensing
IDENTIFICATION OF CRITICAL PROJECT
ELEMENTS
• Have an accuracy and resolution of at least ±3 cm
• Limits how quickly position can be established
• Software
• Synchronized data processing and communication (sensors/microcontroller and
autopilot/microcontroller)
• Design for difference in sensing rates and autopilot command rate
• Sufficient memory for data storage and programming code
• Control laws may need to be translated (Simulink/LabVIEW to C)
• Electrical
• Signal/Connector compatibility between all sensors and autopilot
• Minimize power conversion losses (voltage regulators)
Scout Preliminary Design Review 2013
October 15, 2013
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IDENTIFICATION OF CRITICAL PROJECT
ELEMENTS
• Stability
• Determine multicopter and autopilot sensitivities to center of gravity location
• Design and test mounting/weight distribution strategies (SolidWorks)
• System Integration
• Components purchased, designed, and tested with foresight on the other
components with which they must integrate
• Very important properties: mass and power budgets, signal compatibility and
software languages
Scout Preliminary Design Review 2013
October 15, 2013
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IDENTIFICATION OF CRITICAL PROJECT
ELEMENTS
• Testing Facility
• Testing performed in RECUV’s indoor flying
laboratory (Construction completed Spring 2014)
• Alternate Testing Plan
• Mechanical department’s high speed camera used
with a grid placed on the path of the multicopter
• Grid has known interval quantities to find the
position
• Recording will be used for requirement verification
• Verification
• Must verify both sensor requirements and control requirements are both
under the required ±3 cm independently
Scout Preliminary Design Review 2013
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
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MULTICOPTER SELECTION - RTF X8
Pros
Very large payload capacity (1.5 kg) allows for a variety of design
options
Open source autopilot allows for alterations to be made if the
multicopter is modified in the design process
Mounting areas available on multiple regions of the platform
The included APM 2.6 autopilot system is one of the best available
30 minute assembly time
Width = 0.5 meters
Width (0.36 meters) allows for easy maneuverability through doorway
Uses an Open Source Autopilot
Low cost, within the $3,000 budget
Maximum Payload of 1.5 kg
Cons
Flight Endurance = 10 - 15 min
Moderate flight endurance (10 – 15 minutes)
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RTF X8 - FEASIBILITY ANALYSIS
• Flight Endurance at Max Payload Capacity: 10 – 15 min
• Exceeds the customer requirement of 10 minutes (Requirement 1.2.2)
• Mounting Capability: Variable surface
• Top of platform, bottom of platform and possibility of gimbal integration for
sensors/control system from protruding struts (Requirement 1.2)
Autopilot
Mounting
Top Surface
Scout Preliminary Design Review 2013
Bottom Surface
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RTF X8 - FEASIBILITY ANALYSIS
• Cost: ~$1,200
• Total available budget for multicopter and autopilot of $3,000
• Width: 0.36 meters
• Doorway width defined to be 0.91 meters
2.03
m
0.28 m
Scout Preliminary Design Review 2013
0.36 m 0.28 m
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
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PERFORMANCE SUMMARY
Pros
Light weight (17g)
40.64 mm
[1.6 in]
66.42 mm [2.61 in]
Could be programmed using Arduino IDE
Strong community support
Cons
Not plug-and-play. Needs pre-flight tuning.
Command Rate = 100 HZ
Mass = 17g
Power = 500mW
Open source – 100% modifiable
Active community, many
developers
Scout Preliminary Design Review 2013
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SOFTWARE FUNCTIONALITY:
APM 2.6 AUTOPILOT
Rate Control Loop:
Calculates necessary
motor commands to bring actual
rates closer to commanded rates
Command:
Radio controller
roll, pitch, yaw,
throttle and
climb rates
Scout Preliminary Design Review 2013
Altitude Control Loop:
Calculates necessary motor
commands to bring actual throttle
and climb rate closer to those
commanded
Current rates and altitude
measured by the onboard Inertial
Measurement Unit (IMU)
Motor
Commands
yield new
aircraft state
Multicopter
Control
October 15, 2013
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AUTOPILOT LIMITATIONS
Size and Complexity of Arducopter Software
• Arducopter takes up 94.5% of the board’s programmable memory.
Leaving only 14,332 bytes
• Incorporating additional software into a package not completely
understood is extremely risky
• While Arducopter software could be modified to incorporate our
CDH algorithms, understanding the autopilot code in its entirety is
not feasible for the scope of this project
Limited Processing Power
• ATMEGA 2560 8-bit CPU processor capable of operating at 16MHz
• Only has 8kb of static random access memory (SRAM)
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
October 15, 2013
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SCOUT’S SENSOR MANIPULATION
Laser range finder
scans
environment and
reports 638
ranges at 10Hz
Designed algorithm
computes relative
position of Scout to
each point in the
scan.
Using relative
position,
designed
algorithm
determines
desired
position
Motors on platform actuate and Scout
begins to move
Scout Preliminary Design Review 2013
Designed
algorithm
calculates
rates and throttle
that will result in the
desired position
Arducopter autopilot uses
commanded rates and
throttle to drive motors
October 15, 2013
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ALTERNATIVE SOLUTION: SEPARATE
BOARD FOR SENSOR DATA
MANIPULATION
Pros
Eliminates risk of insufficient
processing power, and memory
Reduces risk of creating bugs within
software.
Could provide extra hardware
capabilities (communication ports)
Cons
Adds additional interface between
microcontroller and APM 2.6.
Additional cost to project
Additional mass and power
requirements
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PERFORMANCE SUMMARY
Pros
Very low power usage (2.5W)
Low cost with $45
BeagleBone
High processing power and memory
Low mass (40g)
Able to run Linux distributions
Strong community support
Cons
•
•
•
•
•
•
Interface = GPIO(92), UART, USB(x1)
Mass = 40g
Power Usage = 2.5W
Processor Speed = 1GHz
RAM = 512MB
Cost = $45
Moderate available ports
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DATA HANDLING
Data to be stored
• Validation of design
• Must record relative position data to verify sensing meets requirements
•
•
•
•
•
BeagleBone Black’s microSD slot
Scout Preliminary Design Review 2013
• Commanded position must also be stored to verify control requirements
are met
• Debugging code
• Storing commands sent to APM will help in debugging software
Maximum Data Storage
• Data stored at 100Hz (same rate as autopilot main loop)
• Storage occurs for entire 10 minute flight endurance
• Each number stored as double precision floating point
(
)
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
October 15, 2013
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URG-04LX-UG01 OVERVIEW
How it works:
● Uses an infrared light source used for area scanning
● Measures a maximum distance of 4000 mm
● Has a sweep function that provides a scan area of 240o that outputs the measured distance
every 683 steps (0.352o)
Non-Radiated Area: 120o
2-D sensing area of the URG
Scout Preliminary Design Review 2013
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MANEUVERING WITH THE 2D LASER
Pitch Concern
•
•
• The 2D laser will use a
sweep function in order
to detect a doorway
• The laser will record
distances along a wall
until a noticeable gap
occurs in the data
The URG will receive the diffused IR
laser when pitched assuming the
wall has a roughness greater than
785 nm
Using the accelerometers to obtain
pitch, the distance to the wall can
be calculated
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ALTERNATIVE DESIGN OPTIONS
Other Sensors
Sensor Shielding
• Develop physical shields
around the sensor that doesn’t
reduce its functionality, but
protects it from Vicon’s infrared
signals
Vicon Notch Filtration
• Use physical filter over camera
system to filter out sensitive
wavelengths
Notch Filter
Scout Preliminary Design Review 2013
• IR Sensors
• Use IR sensors that operate at
different wavelengths to be
outside the range of operation
from the Vicon system
• Imaging
• Projects a grid of lasers on the
wall and captures an image to
determine distance
• Not susceptible to interference
with Vicon system
Using a grid to process distance
TiM3xx IR Sensor
October 15, 2013
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RANGE (URG-04LX-UG01)
• Sensor suite measures relative position 0-1 m from
wall
Wall
Doorway
• The URG has a detection distace of 20 mm to 4000 mm.
(Requirement 1.1)
• Sensor suite measures relative position to a
doorframe while manuevering through
• The URG can determine position from 20 mm to 4000 mm
with a 240o field of view (Requirement 1.1)
• Sensor suite relative position measurements
accurate to within ±3 cm
• At a distance of 20 mm to 1000 mm the URG is accurate
to ±30 mm* (±3 cm). (Requirement 1.1.1)
Sensor Field of View
• Sensor suite capable of distinguishing a doorway
from a wall
• The URG has the ability to determine position at every
point (638 steps) in a field of view of 240o
Scout Preliminary Design Review 2013
*at 1000 mm to 4000 mm the URG is
accurate to ±3% of measurment
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SENSOR FUNCTIONALITY: MB1043
How it works
● Transducer converts electrical energy into
high frequency ultrasonic sound waves,
above 1800Hz
● Sound waves traverse until they hit an
object, at which point they bounce back in
the form of an echo
● Echo sensor recieves echo, and calculates
the distance to the object from time of flight
of the sound waves
● MB 1043 uses RS 232 communication
protocol to interface with processor
● Due to interference from propwash, sensor is
suited for vertical hight rangefinding as
opposed to wall detection
Scout Preliminary Design Review 2013
MB 1043
Outbound
Sound
Waves
Reflected
Sound
Waves
Target
Object
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RANGE (MB 1043 HRLV)
• The sensor suite shall measure its relative position while it is
1-2 m above ground.
• The ultrasound has a detection distance of 30cm to 5000mm (Requirement
1.4)
• The sensor suite shall be capable of continual accurate
measurements to maintain hover of ± 6cm
• Ultrasound sensor takes measurements at a rate of 10Hz with 1mm
accuracy (Requirement 1.4)
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VERTICAL RANGE FINDING
• Statically mounted underneath
Scout facing downward to
measure vertical distance to
ground
• Pitch and roll angles calculated by
accelerometers will be used to
determine Scout’s height in nonlevel states
• Can then calculate vertical
distance to Scout using a rotation
matrix, roll and pitch angles and
the distance measured by the
sensor
Scout Preliminary Design Review 2013
Measured
height
Actual
height
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
Scout Preliminary Design Review 2013
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ELECTRICAL INTERFACE
(SBC & AUTOPILOT)
• The Single Board Compter and APM can communicate through
bidirectional USB ports
• This can be done using the MAVLink Protocol
• SBC running Linux distribution(Angstrom/Ubuntu) could be installed
with MAVLink drivers
• This has been done on the Rasberry Pi / BeagleBoneXM / Odroid /
AsctecAtomBoard proving feasibility
USB Client Ports
BeagleBone
USB HOST
Scout Preliminary Design Review 2013
Autopilot
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ELECTRICAL INTERFACE
(SBC & SENSORS)
BeagleBone Black
URG-04LX-UG01
MB 1043
RS232 , GPIO
RS232 , GPIO
500mA
3.1mA
5V DC
MECHANICAL INTERFACE
• Ensure a mounting design capable of supporting electrical
components on multicopter can be developed
• If a simple mounting set-up is capable of meeting minimum
mounting requirements, then it is feasible that at least one
suitable mounting design can be developed for this project
• At this stage of the design a simple model would be useful for
requirements related to
• Mounting area for components
• Satisfaction of the system’s mass budget
• Preservation of multirotor's flying qualities
• Visibility for sensors
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SIMPLE MOUNTING MODEL
INVESTIGATED
•
Top Plate
• Hokuyo URG-04LX-UG01 (2D laser sensor)
• Bottom Plate:
• BeagleBone Black SBC
• MaxBotics MB1043 (Ultrasound Sensor)
• Samsung Li-Ion battery
2-D
Laser
Ultrasonic
Beagle
Bone
Battery
Length
50 [mm]
50 [mm]
86 [mm]
67 [mm]
Width
40 [mm]
50 [mm]
56 [mm]
36 [mm]
Area
2050
[mm2]
2500 [mm2]
4816[mm2]
2412 [mm2]
Assumptions
•Plates made of polycarbonate (typical engineering plastic)
•Plates will be of length (L), width (W) and thickness (t) equal to 5 mm for both (factor of safety FS = 1.74)
•Both plates are connected to the multirotor via 4 stainless steel bolts (r = ¼ inc) each
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MOUNTING LOCATIONS
Bottom View
Use of pre-existing
holes to attach
plates
2D-Laser Sensor
Autopilot
Single Board
Computer
Battery
Ultrasonic Sensor
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MOUNTING AREA
• The top plate must at least cover a base equal to the autopilot’s
area.  Atop,plate = 2699 mm3 > A2D-Laser = 2050 mm3
• For the bottom plate, area is dictated by the dimensions of the
battery, single board computer, and mounting bolts. 
Abottom,plate = 12,823 mm3
115 mm
BeagleBone
Black (SBC)
Battery
112 mm
Note: Ultrasonic
does not contribute
since is on opposite
side
Bolts
Area division of lower plate
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PREVIOUS MOUNTING
• Example of RTF X8 with
go pro camera and
additional sensors on
the bottom
• Previous examples of
similar equipment
mountings suggest
sufficient area is
available
Arducopter platform provides sufficient space for
attaching mounting plates
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MOUNTING MASS
Conceptual Mounting Mass
Component
Mass [g]
Upper Plate
16
Lower Plate
77
Bolts
TOTAL
Remaining Payload Calculation
Mass [g]
Max Payload
Sensors
1500
-164
781
BeagleBone
Battery
-40
-98
874
Remaining PL
1198
Total conceptual mounting weight < Remaining payload
Weight of simple mounting mechanism does not exceed
available payload (Requirement 1.2.1)
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FLIGHT CHARACTERISTICS
• Mounting mechanism must not disrupt the
aircraft’s flying characteristics by changing its c.g.
• Following equation describes c.g. for a rigid body
of various subcomponents (i)
=0
•
Location of mounted components does not
adversely affect CG location—ensuring
acceptable flight characteristics
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Sensor Visibility
• Placement of upper 2D laser 4.5
inches above the multicopter’s
centered horizontal plane provides
clearance of all structures resulting
in 360o field of view
Unobstructed View
• With the ultrasound facing
downwards relatively over the
multicopter’s geometric center, the
sensor is roughly 29 cm clear of
each propeller
• Assuming inviscid propwash, the
ultrasound has a cone of 32.71o of
unaffected air during a hover of 1m
Mounting mechanism allows sufficient field of view for all sensors
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
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POWER
• Multicopter’s battery will provide power to the Multicopter and Autopilot
• Multicopter’s Battery: Lithium Polymer, 305g, 4000 - 4999mAh
• BeagleBone: 2.5 W (5V, 500mA)
• Hokuyo: 2.5 W (5V, 500 mA)
• Sonar: 0.016 W (5V, 3.1 mA)
• Total:
RTF X8 Battery
for 10 min duration
• These components will be powered by an additional battery separate from
the multicopter’s battery
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SELECTED ADDITIONAL BATTERY
Samsung Li-Ion 18650 Rechargeable Battery
• Capacity: 2800mAh
• Voltage: 7.4V → 20.72 Wh
• Dimensions: 67 mm x 36mm x 18mm
• Weight: 98g
• Max. charge current: 1.75A
• Max. discharge current: 5A
• Cut off voltage:
• Over-Charge Protection: 8.7V
Over-Discharge Protection: 4.6V
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MASS FEASIBILITY SUMMARY
Payload Mass
• CDH: 40 g
• Hokuyo: 160 g
• Sonar: 4 g
• Battery: 98 g
• Mounting: 375 g
• Total: 677.3 g
1.5 kg
• Maximum Payload Capacity: 1500 g
• Payload Margin: 1500 g – 672.3 g =
Remaining Payload for:
677 g
• Stand-offs, Material Changes, Wiring
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COST FEASIBILITY SUMMARY
$5,000
Main Project Budget ($5000)
• Single Board Computer: BeagleBone
• 2D Laser Sensor: URG-04LX-UG01
• Ultrasonic Sensor: MB 1043 HRLV
$45
$1175
$35
• External Battery: Samsung LI-Ion 18650
$25.99
$3,000
Total Cost:
Multicopter/Autopilot Budget (Additional $3000)
Multicopter: RTF X8
• Autopilot: APM 2.6
(Included with Multicopter)
$1,285
Budget Margin: $5000 - $1285 =
Secondary Margin: $3000 - $1200 =
Remaining budget for:
Remaining budget for:
• Mounting, Wiring, Repairs, Backup Units
•
Scout Preliminary Design Review 2013
$1,200
Repair Kit, Spare Parts, Backup Units
October 15, 2013
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Summary
10) Testing
11) Future Work
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TEST FACILITY
• Large open space ideal
for flying Scout safely
• Room for Vicon test
equipment to be
assembled
• Can serve as a base of
operations for the Scout
team
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VICON EQUIPMENT
• Infrared cameras mounted on truss
or tripods flood the test
environment with IR light
• Infrared reflectors attached to
Scout reflect IR, and are tracked
by infrared cameras
• Software uses predefined
geometry of cameras to calculate
position and orientation of Scout
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HIGH SPEED CAMERA
• Mechanical department’s high
speed camera provides an
alternative method of testing
• Would be used in conjunction
with a calibration grid to
measure position of Scout.
Example of a calibration grid,
used for object tracking with
high speed cameras
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Requirements for Testing
• Scout requires an indoor test facility, where it can be flown and tested safely
• The RECUV lab provides a controlled environment where Scout can be tested
• Scout requires test equipment to precisely measure its position and orientation
• Vicon Bonita 10 infrared motion capture system with millimeter level precision
• Mechanical department’s high speed camera with calibration grid (off-ramp)
• Scout must be capable of synchronizing onboard position and state sensor data with
that collected by the indoor flying lab
• Time stamping data acquired by Scout and test equipment
• Sending Scout’s real time data via wireless communication (off-ramp)
(Requirement 1.5.2)
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OVERVIEW
1) Background
2) Requirements
3) Baseline Design
4) Multicopter
5) Autopilot
6) Single Board Computer
7) Sensors
8) Interface
9) Mass/Power/Cost Budget
10) Testing
11) Future Work
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MULTICOPTER FUTURE CONSIDERATIONS
Baseline Design Known Feasibilities
• Meets the budget requirements set by customer
• Interfaces with APM autopilot and allows for mounting of
the BeagleBone, Sensors, and additional batteries
• Meets width and velocity requirements
• Can support the weight of the payload
Future Feasibility Considerations
• Study the sensitivity of the multicopter to center of gravity
shifts
• Characterize the vibrations generated by the multicopter
• Study structural aspects and durability from drawings in
SolidWorks
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Arducopter RTF X8
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AUTOPILOT FUTURE CONSIDERATION
• Baseline Design Known Feasibilities
• Control purchased Multicopter
• Maintain controlled flight
• Satisfies mass, power and cost
requirements
Feedback to
BeagleBone
• Future Considerations
• Determine how to pull feedback data
from APM to BeagleBone
• Determine sensitivity to changes in
center of gravity
• Altering open source code if changes
to Multicopter are made
Scout Preliminary Design Review 2013
Commands to
Multicopter
Commands from
BeagleBone
AMP 2.6 Autopilot
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SBC FUTURE CONSIDERATION
• Baseline Design Known Feasibilities
• Capable of communicating with both sensors and APM
• Operates faster than sensors send data to BeagleBone to
feasibly produce commands
• Contains enough memory to store data for duration of
Sensor
operation
Inputs
• Satisfies mass, power and cost requirement
• Future Considerations
• Develop Code
• Simulate Data Processing
• Translating control laws into usable code
• Plan for difference between 10 Hz sensor data and 100 Hz
APM cycle speed
Scout Preliminary Design Review 2013
BeagleBone Black
Feedback
from APM
Output to
APM
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SENSING FUTURE CONSIDERATIONS
Baseline Design Known Feasibilities
• Able to detect distances both vertically and laterally while maintaining accuracy requirements
• When experiencing dynamic motion, sensor data can be manipulated to determine position
• Sensors meet cost, mass, and power constraints
• Sensors can mount to the multicopter platform and transmit distance data to BeagleBone
Future Feasibility Considerations
• Determine whether the 2D laser scanner can interface with the indoor flying lab
• Managing power and regulating it in order to provide power to the sensors with minimal voltage
loss
• Research the best communication protocol and how to most efficiently transmit the sensor data
BeagleBone Black
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MECHANICAL FUTURE
CONSIDERATIONS
Baseline Design Known Feasibilities
• Mounting design can easily meet cost and payload capacity requirements
• Center of Gravity location is not affected enough to alter flight characteristics
• All of the mission components can be mounted on the platform
Future Feasibility Considerations
• Vibration dampening and mitigation
• Platform’s structure may cause vibrations interfering and/or damaging sensors
• Mounting must dampen out frequencies
• Starting point  spring-mass dampener approximation
• Static and dynamic structural analysis
• Detailed breakdown of static forces on mounting and required structural strength
• Craft’s path in space must be related to applied loads.
• Thermal effects involving motors and electronic components
• Layout satisfy temperature ranges of electrical components
• Center of gravity modeling in CAD
• Find exact position of craft’s center of mass before and after mounting
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REFERENCES
1Hee
Jin Sohn; Byung-Kook Kim, "A Robust Localization Algorithm for Mobile Robots with Laser Range Finders," Robotics and Automation, 2005. ICRA
2005. Proceedings of the 2005 IEEE International Conference on Robotics , pp.3545,3550, 18-22 April 2005
2Steux,
B.; El Hamzaoui, O., "tinySLAM: A SLAM algorithm in less than 200 lines C-language program," Control Automation Robotics & Vision (ICARCV),
2010 11th International Conference on , pp.1975,1979, 7-10 Dec. 2010
3Bachrach,
A.; de Winter, A.; Ruijie He; Hemann, G.; Prentice, S.; Roy, N., "RANGE - robust autonomous navigation in GPS-denied
environments," Robotics and Automation (ICRA), 2010 IEEE International Conference on , pp.1096,1097, 3-7 May 2010
4“Laser
Scanners, TiM3xx / TiM31x / Indoor / Short Range” , SICK Sensor Intelligence.,
https://www.mysick.com/ecat.aspx?go=FinderSearch&Cat=Gus&At=Fa&Cult=English&FamilyID=344&Category=Produktfinder&Selections=53789 [Cited
10 October 2013]
5“Mid
range distance sensors, Dx35 / DS35 / IO-Link” , SICK Sensor Intelligence.,
https://www.mysick.com/ecat.aspx?go=FinderSearch&Cat=Gus&At=Fa&Cult=English&FamilyID=402&Category=Produktfinder&Selections=75114 [Cited
10 October 2013]
6“AT:
Samsung Li-Ion 18650 Cylindrical 7.4V 2800mAh Flat Top Rechargeable Battery w/ PCM Protection” , All-Battery.com, Total Power Solutions,
http://www.all-battery.com/SamsungLi-Ion18650_7.4V_2800mAhwithPCM-31444.aspx [Cited 13 October 2013]
7“BeagleBone
Black” , beagleboard.org, http://beagleboard.org/Products/BeagleBone%20Black [Cited 7 October 2013]
8“URG-04LX-UG01
Product Information”, Hokuyo Automatic Co., http://www.hokuyo-aut.jp/02sensor/07scanner/download/products/urg-04lx-ug01/,
[September 23, 2013]
9“MB1043
10“3DR
RTF X8,” 3D Robotics UAV Technology, http://store.3drobotics.com/products/apm-3dr-x8-rtf, [cited 22 September 2013]
11“APM
12“Laser
2.6 Set (external compass),” 3D Robotics UAV Technology, http://store.3drobotics.com/products/apm-2-6-kit-1, [cited 25 September 2013]
Grid GS1,” GhostStop Ghost Hunting Equipment, http://www.ghoststop.com/Laser-Grid-GS1-p/laser-lasergrid-gs1.htm, [cited 10 October 2013]
13“Notch
14“X8
HRLV-MaxSonar®-EZ4? Product”, MaxBotix, http://www.maxbotix.com/Ultrasonic_Sensors/MB1043.htm, [September 27, 2013]
Filters,” Thor Labs, http://www.thorlabs.us/NewGroupPage9.cfm?ObjectGroup_ID=3880&, [cited 10 October 2013]
Motor Out Test,” YouTube.com, http://www.youtube.com/watch?v=cdS6Cy5aOvk, [cited 4 October 2013]
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QUESTIONS?
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APPENDIX
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DESCRIPTION OF QUALITATIVE
TRADE VALUES
• Integration Capability:
• Values for this category indicate how easily the source code of the autopilot can be viewed
and manipulated. An
•
•
•
•
•
Extreme in this category indicates that the source code is readily available and easily manipulated.
High suggests that the source code is somewhat scattered, but still easily manipulated.
Medium indicates the source code is heavily scattered, and somewhat difficult to modify.
Low indicates the source code is difficult to locate and difficult to modify.
Locked suggests the source code is unavailable and impossible to modify.
• Documentation:
• Values in this category indicate how easily it is to find information regarding the source
code, as well as the activity of the development community.
• Very good: Indicates that the documentation is thorough and easily understandable,
and the community is well versed an active.
• Good: Suggests the documentation exists, but may not be thorough, and the
community is active but amateur.
• Medium: Some documentation of code missing, community is active but amateur
• Low: Little documentation of how the code functions, community is small
• Very Low: No documentation of how the code functions, community is small or
unexistant
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WEIGHTING SCALE
• Mounting Capability
• A high ranking (very good) in this category will mean that multiple surfaces are available
for mounting, and are not restricted by other components of the multicopter.
• A poor ranking (very low) in this category will mean that only one area is available for
mounting, and it may not allow for all of the components necessary for the mission.
• Durability
Methods of Analysis
Arm thickness, length and material composition
Platform and propeller materials
Customer reviews
All of these parameters were taken into account in order to give an overall score for
durability
• A very good score in this section would mean that each component performed very well
• A very low score would mean that almost, if not all of the components performed poorly
•
•
•
•
•
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WEIGHTING TABLE
Trade parameters with
corresponding score
ranges
Only parameters that
evaluate ability to satisfy
mission requirements
included
Not included in trade
study:
• Velocity
• Assembly time
• Height and length
dimensions
Trade Parameters
Score 5
Score 4
Score 3
Score 2
Score 1
Width
< 0.3m
0.3 - 0.4m
0.4 - 0.5m
0.5 - 0.6m
0.6m <
Mounting
Capability*
Very Good
Good
Medium
Low
Very Low
Durability*
Very Good
Good
Medium
Low
Very Low
Flight Endurance
> 25 min
20 - 15 min 15 - 10 min
10 - 5 min
5 min >
Payload Capacity
> 1.4 kg
1.4 - 1.1 kg 1.1 - 0.8 kg
0.8 - 0.5 kg
0.5 kg >
Cost
< $500
$1150 $1500
> $1500
$500 $850
$850 $1150
* Reasoning for qualitative descriptions given in appendix
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MULTICOPTER SELECTION
• All capable of completing mission
• Narrowed selection down to the top three (highlighted in blue)
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FURTHER RESEARCH AND ELIMINATION
• Trade study was perfomed on 9 different multicopters, top 3 analyzed
further
• Used highest weighted parameters for further analysis
• Performed low in payload capacity (highest weighted category)
• Closed source autopilot adds unnecessary design complications
DJI Phantom
SteadiDrone QU4D
− Width = 0.35 meters
− Width = 0.61 meters
− Uses a Naza–M Closed Source Autopilot
− Used an Open Source Autopilot
− Maximum Payload of 1 kg
− Maximum Payload of 0.8 kg
− Flight Endurance = 10 – 15 min
− Flight Endurance = 25 min
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AUTOPILOT SELECTION
Trade parameters with
corresponding score ranges
Only parameters that
evaluate ability to satisfy
mission requirements included
Not included in trade study:
• Included Sensors
• Included Components
• Default Sensing
Resolution
Trade Parameters
Score 5
Score 4
Score 3
Score 2
Score 1
Integration
Capability*
Extreme
High
Medium
Low
Locked
Weight
8 - 17g
18 - 27g
28 - 36g
37 - 45g
46 - 55g
Power
250 – 320
mW
321 – 390
mW
391 – 460
mW
461 – 530
mW
531 – 600
mW
Cost
$149 - 228
$229 307
$308 - 386
$387 - 465
$466 544
Command Rate
341 – 400 Hz
281 – 340
Hz
221 – 280
Hz
161 – 220
Hz
100 – 160
Hz
Documentation*
Very Good
Good
Medium
Low
Very Low
* Reasoning for qualitative descriptions given in appendix
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AUTOPILOT SELECTION
• All capable of completing mission
• Narrowed selection down to the three top performing
(highlighted in blue)
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DOWN SELECTION OF FINAL
AUTOPILOTS
• Integration with best multicopter (with highest payload capacity) was
top priority
PX4FMU
•
•
•
•
Untested use onboard chosen platform
Command Rate = 200Hz
Scientifically astute developer community
Incredible documentation, all well
organized
Scout Preliminary Design Review 2013
AeroQuad 32
• Untested use onboard any well
performing platform
• High power draw (500mW)
• Command rate = 100Hz
• Large developer community
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TRADE PARAMETERS
Qualitative Trade Parameters:
• Integration – defined by the
difficulty to mount and
interface with microcontroller
(with the knowledge of the
team)
• Resistance to Disturbances –
defined by the sensors ability
to overcome disturbances
such as dust particles,
propeller wash, and vibrations
• Usable Surfaces – defined by
the surfaces the sensor is
accurate on (i.e. carpet,
stucco wall, etc..)
• Documentation – defined by
the completeness of
documentation
Scout Preliminary Design Review 2013
Trade Parameters
Score 5
Score 4
Score 3
Score 2
Score 1
Power Consumption
< 1W
1-2W
2.1-3W
3.1-4W
> 4.1W
Integration
Easy
Moderate
Average
Challenging
Difficult
Overdoes
Required Range
Exceeds
Required
Range
Meets
Required
Range
Range
Accuracy
<±10 mm
±11-20 mm
Meets Little
Meets Some of
of Required
Required Range
Range
±21-30 mm
±31-50 mm
>±50 mm
Resistance to
Disturbances
Very Good
Good
Medium
Low
Very Low
Usable Surfaces
Very Good
Good
Medium
Low
Very Low
Weight
< 10g
10 -70g
70 - 130g
130 - 200g
> 200g
Field of View
>100o
45o-99o
20o-44o
5o-19o
<5o
Resolution
<1 mm
6mm
50mm
10 cm
>20 cm
Cost
< $100
$100 - $300
$300 - $600
$600 - $1300
> $1300
Very Good
Good
Medium
Low
Very Low
Documentation
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SENSOR SELECTION
• Did a trade study of different types of sensors, but not
one sensor could complete the mission alone.
• A combination of sensors needed to be chosen
• The top two sensors can be seen, which happen to
work well in combination.
MICROCONTROLLER/SBC
SELECTION
Trade Parameters
Score 5
Score 4
Score 3
Score 2
Score 1
Available Ports
Extreme (>2 USB,
GPIO,>1 UART)
High (USB, GPIO ,
UART)
Medium (USB,
GPIO/UART)
Low (USB)
Very Low
(Requires
Expansion)
Mass
20g – 40g
41g – 60g
61g – 80g
81g – 100g
>101g
Power
2W-4W
5W-6W
7W-8W
9W-10W
>11W
Processor Speed
1743Hz - 1535Hz
1534Hz - 1327Hz
1326Hz - 1118Hz
1117Hz - 909Hz
908Hz - 700Hz
Memory
2051MB – 1744MB
1743MB – 1436MB
1435MB –
1128MB
1127MB –
820MB
819MB – 512MB
Cost
$35 - $64
$65 - $94
$95 - $124
$125 - $154
>$155
Documentation*
Very Good
Good
Medium
Low
Very Low
Not included in trade
study: Operating System
Support
Scout Preliminary Design Review 2013
* Reasoning for qualitative descriptions given in appendix
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MICROCONTROLLER/SBC SELECTION
• All capable of completing mission
• Narrowed selection down to the three top performing
(highlighted in blue)
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FURTHER RESEARCH AND ELIMINATION
Rasberry Pi
•
•
•
•
•
•
Interface = GPIO(17), UART, USB(x2)
Weight = 90g
Power Usage = 5W
Processor Speed = 1.6GHz
RAM = 512MB
Cost = $35
Scout Preliminary Design Review 2013
Odroid X2
•
•
•
•
•
•
Interface = GPIO(50), UART, USB(x6)
Weight = 82g
Power Usage = 20W
Processor Speed = 1.2GHz
RAM = 1GB
Cost = $182
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PREVIOUS SOLUTIONS
• Scout must be capable of determining its
relative position to objects in its environment
• Robotics community has addressed this
problem via simultaneous localization and
mapping (SLAM) algorithms
• SLAM imposes its own challenges:
• Processing the range data is computationally
intensive and is usually done off board the
vehicle
• When data is processed onboard, it generally
occurs on powerful microcontrollers boasting
32bit CPU capable of clocking at GHz speeds,
with at least 512Mb random access memory
(RAM)
A map generated by an autonomous
land rover, using laser range data and
a SLAM algorithm
NEEDED ADAPTATIONS TO SUITE PROJECT:
• Mapping an environment is out of the scope of this project:
• SLAM is so computationally intensive because it “stiches” thousands of scans together to create
a seamless map of the environment
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INTERFACE FEASIBILITY
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FLIGHT CHARACTERISTICS
• Assuming mass symmetric placement of autopilot, sensors, electrical
components and mounting  change in c.g. only occurs along
vertical axis.
• The following relation becomes the result:
• To avoid the propellers of the craft, yupper = 11.43 cm 
ylower = 0.92 cm
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SIZING (MB1043 HRLV)
● The weight of the MB 1043 sensor is 4.3g
● Additional 5g of weight on Scout is feasible according to mass budget
● Small, 0.20cm x 0.22cm x 0.155cm, can be placed under Scout, takes up minimal space.
Payload
0.75 kg
A
19.9 mm
B
22.1 mm
K
16.4 mm
J
15.5 mm
1.5 kg
DETECTION OF DOOR
• The sampling frequency of the URG is 10 Hz.
• Moving at 0.2 m/s the sensor will detect a point every 20 cm in between
sweeps. Since the doorframe is ~.9 m wide this gap can be detected.
• Using the diagram shown below and knowing
minimum detected door thickness would be 0.28 cm
Doorframe
and
m the
SIZING (URG-04LX-UG01)
● The fact that only one is needed cuts down
additions the the mass budget.
● The weight of the URG sensor is
approximately 160g
● (Add note on how we are in the weight
budget and if it is feasible to add 160g)
● (Add note on mounting surface that we
can put it on)
*all units in mm
Payload
0.75 kg
1.5 kg