Development and Validation of the Rensselaer Multicopter ...
PRELIMINARY DESIGN REVIEW - University of Colorado Boulder · PRELIMINARY DESIGN REVIEW Team Scout:...
Transcript of PRELIMINARY DESIGN REVIEW - University of Colorado Boulder · PRELIMINARY DESIGN REVIEW Team Scout:...
PRELIMINARY DESIGN REVIEW Team Scout: Austin Anderson, Geoff Inge, Ethan Long, Gavin Montgomery, Mark Onorato, Suresh Ratnam, Eddy Scott, Tyler Shea, Marcell Smalley
October 15, 2013 Scout Preliminary Design Review 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
October 15, 2013 Scout Preliminary Design Review 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
October 15, 2013 Scout Preliminary Design Review 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
October 15, 2013 Scout Preliminary Design Review 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
October 15, 2013 Scout Preliminary Design Review 2013 5
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
October 15, 2013 Scout Preliminary Design Review 2013 6
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
October 15, 2013 Scout Preliminary Design Review 2013 7
Power up and maintain
hover at 1-2 m above the
ground.
Begin Searching for
doorway 0-1 m away from
wall
Determine when a 0.9 m
by 2 m doorway is present
and stop searching.
Maneuver through the
doorway and cease
operation.
Side View
Top View
Floor
Doorway Wall
Floor
Doorway
Wall
CONCEPT OF OPERATIONS
October 15, 2013 Scout Preliminary Design Review 2013 8
FUNCTIONAL BLOCK DIAGRAM
October 15, 2013 Scout Preliminary Design Review 2013 9
BASELINE DESIGN
Multicopter: Arducopter RTF X8
Control: APM 2.6 running Arducopter
autopilot Sensor:
Hokuyo URG-04LX-UG01
Sensor:
MaxBotics MB1043
Command/Data Handling:
BeagleBone Black
APM mounted
directly on
multicopter
upper surface
Ultrasound placed on
lower mounting .
Faces floor
CDH mounted on
lower mounting.
Facing upward
2D Laser mounted on
upper mounting facing
platform's path
October 15, 2013 10
Sensor Data Telemetry Data Logic Command AutoPilot Command
GPIO, RS 232, Digital USB, MAVLink, Digital Voltage Command
Ultrasonic Sensor (MB1043)
Laser Sensor (URG-04LX-UG01 )
BeagleBone Black
APM 2.6 Autopilot 3DR RTF X8
Acquires vertical position measurement
Acquires lateral position measurement
Processes position and telemetry data and sends “stick” command to APM
Processes input from Beaglebone and sends commands to motors
Autonomously flies through the doorway using
APM voltage commands
SCOUT INTERFACE SUMMARY
October 15, 2013 Scout Preliminary Design Review 2013 11
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
October 15, 2013 Scout Preliminary Design Review 2013 12
IDENTIFICATION OF CRITICAL PROJECT ELEMENTS
Design Challenges
• Sensing • 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)
October 15, 2013 Scout Preliminary Design Review 2013 13
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
October 15, 2013 Scout Preliminary Design Review 2013 14
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
October 15, 2013 Scout Preliminary Design Review 2013 15
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
October 15, 2013 Scout Preliminary Design Review 2013 16
MULTICOPTER SELECTION - RTF X8
Width = 0.5 meters
Uses an Open Source Autopilot
Maximum Payload of 1.5 kg
Flight Endurance = 10 - 15 min
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 (0.36 meters) allows for easy maneuverability through doorway
Low cost, within the $3,000 budget
Cons
Moderate flight endurance (10 – 15 minutes)
October 15, 2013 Scout Preliminary Design Review 2013 17
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)
Bottom Surface Top Surface
Autopilot
Mounting
October 15, 2013 Scout Preliminary Design Review 2013 18
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
0.36 m 0.28 m 0.28 m
2.03
m
October 15, 2013 Scout Preliminary Design Review 2013 19
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
October 15, 2013 Scout Preliminary Design Review 2013 20
PERFORMANCE SUMMARY
66.42 mm [2.61 in]
40.6
4 m
m
[1.6
in
]
Command Rate = 100 HZ
Mass = 17g
Power = 500mW
Open source – 100% modifiable
Active community, many
developers
Pros
Light weight (17g)
Could be programmed using Arduino IDE
Strong community support
Cons
Not plug-and-play. Needs pre-flight tuning.
October 15, 2013 Scout Preliminary Design Review 2013 21
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
Altitude Control Loop:
Calculates necessary motor
commands to bring actual throttle
and climb rate closer to those
commanded
Motor
Commands
yield new
aircraft state
Current rates and altitude
measured by the onboard Inertial
Measurement Unit (IMU)
Multicopter
Control
SOFTWARE FUNCTIONALITY: APM 2.6 AUTOPILOT
October 15, 2013 Scout Preliminary Design Review 2013 22
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)
AUTOPILOT LIMITATIONS
October 15, 2013 Scout Preliminary Design Review 2013 23
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
October 15, 2013 Scout Preliminary Design Review 2013 24
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
Designed algorithm
calculates
rates and throttle
that will result in the desired position
Arducopter autopilot uses
commanded rates and
throttle to drive motors
Motors on platform actuate and Scout
begins to move
October 15, 2013 Scout Preliminary Design Review 2013 25
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
October 15, 2013 Scout Preliminary Design Review 2013 26
PERFORMANCE SUMMARY
• Interface = GPIO(92), UART, USB(x1)
• Mass = 40g
• Power Usage = 2.5W
• Processor Speed = 1GHz
• RAM = 512MB
• Cost = $45
BeagleBone
Pros
Very low power usage (2.5W)
Low cost with $45
High processing power and memory
Low mass (40g)
Able to run Linux distributions
Strong community support
Cons
Moderate available ports
October 15, 2013 Scout Preliminary Design Review 2013 27
DATA HANDLING
• Validation of design
• Must record relative position data to verify sensing meets requirements
• Commanded position must also be stored to verify control requirements are met
• Debugging code
• Storing commands sent to APM will help in debugging software
Data to be stored
•
•
•
•
•
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
(
)
BeagleBone Black’s microSD slot
October 15, 2013 Scout Preliminary Design Review 2013 28
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
October 15, 2013 Scout Preliminary Design Review 2013 29
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)
2-D sensing area of the URG
Non-Radiated Area: 120o
October 15, 2013 Scout Preliminary Design Review 2013 30
MANEUVERING WITH THE 2D LASER
• 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
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
October 15, 2013 Scout Preliminary Design Review 2013 31
ALTERNATIVE DESIGN OPTIONS
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
Other Sensors
• 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 Scout Preliminary Design Review 2013 32
RANGE (URG-04LX-UG01)
• Sensor suite measures relative position 0-1 m from wall
• 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 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
Doorway Wall
Sensor Field of View
*at 1000 mm to 4000 mm the URG is
accurate to ±3% of measurment October 15, 2013 Scout Preliminary Design Review 2013 33
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
Outbound
Sound
Waves
Reflected
Sound
Waves Target
Object
MB 1043
October 15, 2013 Scout Preliminary Design Review 2013 34
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)
October 15, 2013 Scout Preliminary Design Review 2013 35
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 non-level states
• Can then calculate vertical distance to Scout using a rotation matrix, roll and pitch angles and the distance measured by the sensor
Measured
height
Actual
height
October 15, 2013 Scout Preliminary Design Review 2013 36
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
October 15, 2013 Scout Preliminary Design Review 2013 37
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
BeagleBone
Autopilot
USB HOST
USB Client Ports
October 15, 2013 Scout Preliminary Design Review 2013 38
RS232 , GPIO
URG-04LX-UG01
BeagleBone Black
MB 1043
500mA 3.1mA
RS232 , GPIO
5V DC
ELECTRICAL INTERFACE (SBC & SENSORS)
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
October 15, 2013 Scout Preliminary Design Review 2013 40
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
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
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]
October 15, 2013 Scout Preliminary Design Review 2013 41
MOUNTING LOCATIONS
Use of pre-existing
holes to attach
plates
Ultrasonic Sensor
Autopilot
Single Board
Computer
Bottom View
Battery
2D-Laser Sensor
October 15, 2013 Scout Preliminary Design Review 2013 42
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
Area division of lower plate
BeagleBone
Black (SBC)
Battery
115 mm
112 mm
Note: Ultrasonic
does not contribute
since is on opposite
side Bolts
October 15, 2013 Scout Preliminary Design Review 2013 43
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
October 15, 2013 Scout Preliminary Design Review 2013 44
MOUNTING MASS
Component Mass [g]
Upper Plate 16
Lower Plate 77
Bolts 781
TOTAL 874
Total conceptual mounting weight < Remaining payload
Weight of simple mounting mechanism does not exceed
available payload (Requirement 1.2.1)
Mass [g]
Max Payload 1500 Sensors -164
BeagleBone -40 Battery -98
Remaining PL 1198
Conceptual Mounting Mass Remaining Payload Calculation
October 15, 2013 Scout Preliminary Design Review 2013 45
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
October 15, 2013 Scout Preliminary Design Review 2013 46
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
• 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
October 15, 2013 Scout Preliminary Design Review 2013 47
Unobstructed View
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
October 15, 2013 Scout Preliminary Design Review 2013 48
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: for 10 min duration
• These components will be powered by an additional battery separate from the multicopter’s battery
RTF X8 Battery
October 15, 2013 Scout Preliminary Design Review 2013 49
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
October 15, 2013 Scout Preliminary Design Review 2013 50
MASS FEASIBILITY SUMMARY
• Maximum Payload Capacity: 1500 g
• Payload Margin: 1500 g – 672.3 g =
Remaining Payload for:
• Stand-offs, Material Changes, Wiring
1.5 kg
677 g
Payload Mass • CDH: 40 g
• Hokuyo: 160 g
• Sonar: 4 g
• Battery: 98 g
• Mounting: 375 g
• Total: 677.3 g
October 15, 2013 Scout Preliminary Design Review 2013 51
COST FEASIBILITY SUMMARY
Main Project Budget ($5000)
• Single Board Computer: BeagleBone $45
• 2D Laser Sensor: URG-04LX-UG01 $1175
• Ultrasonic Sensor: MB 1043 HRLV $35
• External Battery: Samsung LI-Ion 18650 $25.99
Total Cost:
Multicopter/Autopilot Budget (Additional $3000)
Multicopter: RTF X8
• Autopilot: APM 2.6 (Included with Multicopter)
Budget Margin: $5000 - $1285 =
Remaining budget for:
• Mounting, Wiring, Repairs, Backup Units
$5,000
$1,285
$3,000
$1,200 Secondary Margin: $3000 - $1200 =
Remaining budget for:
• Repair Kit, Spare Parts, Backup Units
October 15, 2013 Scout Preliminary Design Review 2013 52
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
October 15, 2013 Scout Preliminary Design Review 2013 53
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
October 15, 2013 Scout Preliminary Design Review 2013 54
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
October 15, 2013 Scout Preliminary Design Review 2013 55
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
October 15, 2013 Scout Preliminary Design Review 2013 56
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)
October 15, 2013 Scout Preliminary Design Review 2013 57
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
October 15, 2013 Scout Preliminary Design Review 2013 58
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
Arducopter RTF X8
October 15, 2013 Scout Preliminary Design Review 2013 59
• Baseline Design Known Feasibilities
• Control purchased Multicopter
• Maintain controlled flight
• Satisfies mass, power and cost requirements
• 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
Commands to
Multicopter Commands from
BeagleBone
Feedback to
BeagleBone
AUTOPILOT FUTURE CONSIDERATION
AMP 2.6 Autopilot
October 15, 2013 Scout Preliminary Design Review 2013 60
• 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 operation
• 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
Sensor
Inputs
Feedback
from APM
Output to
APM
SBC FUTURE CONSIDERATION
BeagleBone Black
October 15, 2013 Scout Preliminary Design Review 2013 61
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
October 15, 2013 Scout Preliminary Design Review 2013 62
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
October 15, 2013 Scout Preliminary Design Review 2013 63
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 HRLV-MaxSonar®-EZ4? Product”, MaxBotix, http://www.maxbotix.com/Ultrasonic_Sensors/MB1043.htm, [September 27, 2013]
10“3DR RTF X8,” 3D Robotics UAV Technology, http://store.3drobotics.com/products/apm-3dr-x8-rtf, [cited 22 September 2013]
11“APM 2.6 Set (external compass),” 3D Robotics UAV Technology, http://store.3drobotics.com/products/apm-2-6-kit-1, [cited 25 September 2013]
12“Laser Grid GS1,” GhostStop Ghost Hunting Equipment, http://www.ghoststop.com/Laser-Grid-GS1-p/laser-lasergrid-gs1.htm, [cited 10 October 2013]
13“Notch Filters,” Thor Labs, http://www.thorlabs.us/NewGroupPage9.cfm?ObjectGroup_ID=3880&, [cited 10 October 2013]
14“X8 Motor Out Test,” YouTube.com, http://www.youtube.com/watch?v=cdS6Cy5aOvk, [cited 4 October 2013]
October 15, 2013 Scout Preliminary Design Review 2013 64
QUESTIONS?
October 15, 2013 Scout Preliminary Design Review 2013 65
APPENDIX
October 15, 2013 Scout Preliminary Design Review 2013 66
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
October 15, 2013 Scout Preliminary Design Review 2013 67
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
October 15, 2013 Scout Preliminary Design Review 2013 68
WEIGHTING TABLE
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 $500 - $850
$850 - $1150
$1150 - $1500
> $1500
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
* Reasoning for qualitative descriptions given in appendix
October 15, 2013 Scout Preliminary Design Review 2013 69
MULTICOPTER SELECTION
• All capable of completing mission
• Narrowed selection down to the top three (highlighted in blue)
October 15, 2013 Scout Preliminary Design Review 2013 70
FURTHER RESEARCH AND ELIMINATION
− Width = 0.35 meters
− Uses a Naza–M Closed Source Autopilot
− Maximum Payload of 1 kg
− Flight Endurance = 10 – 15 min
− Width = 0.61 meters
− Used an Open Source Autopilot
− Maximum Payload of 0.8 kg
− Flight Endurance = 25 min
• 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
SteadiDrone QU4D DJI Phantom
October 15, 2013 Scout Preliminary Design Review 2013 71
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
AUTOPILOT SELECTION
* Reasoning for qualitative descriptions given in appendix
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
October 15, 2013 Scout Preliminary Design Review 2013 72
AUTOPILOT SELECTION
• All capable of completing mission
• Narrowed selection down to the three top performing
(highlighted in blue)
October 15, 2013 Scout Preliminary Design Review 2013 73
DOWN SELECTION OF FINAL AUTOPILOTS
PX4FMU AeroQuad 32
• Untested use onboard chosen platform
• Command Rate = 200Hz
• Scientifically astute developer community
• Incredible documentation, all well
organized
• Untested use onboard any well
performing platform
• High power draw (500mW)
• Command rate = 100Hz
• Large developer community
• Integration with best multicopter (with highest payload capacity) was
top priority
October 15, 2013 Scout Preliminary Design Review 2013 74
TRADE PARAMETERS
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
Range Overdoes
Required Range
Exceeds
Required
Range
Meets
Required
Range
Meets Some of
Required Range
Meets Little
of Required
Range
Accuracy <±10 mm ±11-20 mm ±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
Documentation Very Good Good Medium Low Very Low
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
October 15, 2013 Scout Preliminary Design Review 2013 75
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
* Reasoning for qualitative descriptions given in appendix Not included in trade
study: Operating System
Support October 15, 2013 Scout Preliminary Design Review 2013 77
MICROCONTROLLER/SBC SELECTION
• All capable of completing mission
• Narrowed selection down to the three top performing
(highlighted in blue) October 15, 2013 Scout Preliminary Design Review 2013 78
FURTHER RESEARCH AND ELIMINATION
Odroid X2 Rasberry Pi
• Interface = GPIO(17), UART, USB(x2)
• Weight = 90g
• Power Usage = 5W
• Processor Speed = 1.6GHz
• RAM = 512MB
• Cost = $35
• Interface = GPIO(50), UART, USB(x6)
• Weight = 82g
• Power Usage = 20W
• Processor Speed = 1.2GHz
• RAM = 1GB
• Cost = $182
October 15, 2013 Scout Preliminary Design Review 2013 79
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 October 15, 2013 Scout Preliminary Design Review 2013 80
INTERFACE FEASIBILITY
October 15, 2013 Scout Preliminary Design Review 2013 81
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
October 15, 2013 Scout Preliminary Design Review 2013 82
Payload 0.75 kg 1.5 kg
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.
A 19.9 mm
B 22.1 mm
K 16.4 mm
J 15.5 mm
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
and
m the minimum detected door thickness would be 0.28 cm
Doorframe
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