Critical Design Review - colorado.edu · Critical Design Review Austin Anderson Suresh Ratnam Geoff Inge Eddy Scott Ethan Long Tyler Shea ... CDE 4 All components must be within the

Critical Design Review

Austin Anderson Suresh Ratnam Geoff Inge Eddy Scott Ethan Long Tyler Shea Gavin Montgomery Marcell Smalley Mark Onorato

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

12/2/2013 Aerospace Engineering Sciences - Scout Slide 2

Level 1 Objective: Sensing

Measure altitude and relative

position with ±3cm

Side View

Top View

Floor

Doorway Wall

Floor

Doorway

Wall

3

Level 2 Objective: Motion

Maintain hover ±6cm

Control position with ±6cm

Level 3 Objective: Doorway

Search and Maneuver

Search and fly through

doorway

±6cm

1m

1m

Concept of Operations

12/2/2013 Aerospace Engineering Sciences - Scout

Upper Mounting

Lower Mounting

Multicopter CAD Design

Time of Flight Camera

Upper Mounting Plate

Upper Plate Ballast

Lower Plate Ballast

Supplemental Battery

Lower Mounting Plate Ultrasound Sensor

BeagleBone Black


Mounting CAD Design

Functional Block Diagram


Electrical Design Solution

•One compact package powered from a separate battery

•Breakout board:

•used for voltage regulation •compact way to group

connections

•Two voltage regulators: •Switching •LDO


Critical Project Elements

Critical Project Element Consequence of Failure

CDE 1 Design must be capable of precision control in order to maneuver through the door

Without precision control attempting to maneuver through a doorway will result in crashes

CDE 2 Relative position measurements need to be precise to achieve precision control

If the position measurements are inaccurate the control system will be ineffective

CDE 3 Onboard power supply must enable 10 minutes of mission capabilities

Failure to meet customer requirements

CDE 4 All components must be within the payload capacity of the chosen multicopter

If the vehicle can not become airborne it will not be able to maneuver through the door


Key Design Requirements

Design Requirement Parent Requirement

DR1 The sensor suite shall measure its relative position while within 1m from the wall at an altitude of 0-2m

CDE 2

DR2 The sensor suite’s relative position measurement shall be accurate to within ±3cm

CDE 2

DR3 The sensor suite shall be within the 1.5kg payload capacity of the multicopter

CDE 4

DR4 Power shall be supplied to the sensor suite for a minimum duration of 10 minutes

CDE 3

DR5 All components shall be capable of integrating with appropriate connections and protocols to transfer data

CDE 2

DR6 Scout shall be capable of controlled hovering and maneuvering within +/- 6cm of a commanded position

CDE 1

DR7 Using its sensor suite data, Scout shall be able to detect a doorway CDE 2


Design Requirements

Design Requirement 1 The sensor suite shall measure its relative position while within 1m from the wall at an altitude of 1-2m


1-2 m

1 m

Lateral Positioning

75 mm

57 mm

26 mm

Argos P100 Time of Flight Camera

• USB 2.0 and supported by Linux OS for interfacing with BeagleBone

• Comes with a software development kit to understand functionality early

Important Specifications

• Range: 3 meters

• Field of view: 90o

• Accuracy: ±1 mm at 1 m

• Up to 160 frames per second at 160 x 120 pixels

Initially found using a 2D scanning Laser, changed because of testing interference


Time of Flight Camera Operation

• Uses two illumination LEDs operating at 850 nm

• Integrated Circuit captures reflected light and uses distance equation to determine ranges

• Camera returns an array of depth data in meters

• Will be used on a white test wall for best results

Camera Reference Frame for Range Data

Integrated Circuit

LED

𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 =𝑐 ∗ 𝑡𝑖𝑚𝑒

2

𝑐 = 3𝑥108 m/s


Time of Flight Simulation


Finding Wall at Startup


Vertical Positioning

How it works

● High frequency ultrasonic sound waves are output from the sensor and traverse until reflected by an object

● The time of flight from output to detection is used to calculate distance

● Uses RS232 communication protocol

● Interference from propwash causes sensor use only for vertical rangefinding

Important Specifications

• Range: 7.7 meters

• Accuracy: ±3 cm

• Readings occur at 10 Hz

Outbound Sound Waves

Reflected Sound Waves Target

Object

Ultrasonic MB 1240


Space and Visibility for Hardware

Upper Plate, Top View

Upper Plate, Bottom View Lower Plate, Bottom View Lower Plate, Top View

Major factors of plate dimensions: • Rectangular geometry is easy to manufacture • Components placed for smallest possible footprint • Clearance on plate for electrical components and

standoffs • Mounting placement on copter


Ballast

Ballast

T.O.F. Camera

Ultrasonic Sensor

BeagleBone Black Battery

Space and Visibility for Hardware

Visibility Cone of Camera Diagram

Argos Camera Visibility Considerations: • Lateral Visibility

• 90o maximum field of view gained by clearance over props

• Vertical Visibility • 35% vertical field of view

obstructed by propeller

Ultrasound Field of View • Central placement on lower

plate provides unobstructed view


Design Requirement 2 The sensor suite relative position measurement shall be accurate to within ±3cm


+3 cm -3 cm

Measured Distance

Wall/Ground

Sensor

Ultrasound Error Ultrasound and Angle Error: Ultrasound (max) Error Only:

•Maximum error in Ultrasound: ± 3 cm •Maximum error in Gyro’s (Angle): ± 2% of angle •Randomly generated error between those two bounds iterated 100 times •Scout is limited to 10° roll angle


Camera Error

• Error never exceeds limit on white wall • Error doesn’t exceed limit until 2.7 meters on Gray wall • Take closest point of range data for distance to wall

•Works up to 45° Yaw from perpendicular •Average data from pixels around the closest point to increase accuracy

Camera Range Data For: 1m from wall, 20° Yaw


Design Requirement 3 The sensor suite shall be within the 1.5kg payload capacity of the multicopter


Negligible Disturbance of CG

z

z

z

y

y

y

x x x ballast

•Noting symmetry Standoffs don’t contribute X and Z components •Z locations of lower arrangement negotiated with zero cross moments req. Ballast added for simplicity (39.7 g of Aluminum) • Y component dictated lower standoffs (both standoffs have L = 39.8 mm). Ballast added to retain reasonable relative standoff lengths (113.7 g of Aluminum)


dm

Cross Moments of Inertia

z

z

y x z

y

x

y

x z

z

x y

Breakdown integrations by component: •Upper – Camera is placed at x = z = 0 and it’s relatively symmetric about all 3 axes, all three cross moments of inertia equal zero •Lower – Because all lower components are symmetric about z-y and x-z planes, parallel axis components (dx, dy and dz ) dictate cross-moments of inertia

ballast


dm

Mass Summary

• Maximum Payload Capacity: 1500 g

• Payload Margin: 1500 g – 559 g =

1.5 kg

559 g

Payload Mass • BeagleBone Black: 40 g • Camera: 140 g • Ultrasonic: 4 g • External Battery: 138 g • Mounting: 217 g • PCB: 20 g

• Total: 559 g


Design Requirement 4 Power shall be supplied to the sensor suite for a minimum duration of 10 minutes


Power Budget

240 = 1.5 𝑚𝑠 ∗ 40 𝑓𝑝𝑠 ∗ 4

Component Current Voltage Power

BeagleBone Black 1A 5V 5W

Argos P-100 Time of Flight Camera

1.5A 5V 7.5W

MB1261 Ultrasonic Sensor

100mA 5V 0.5W

Total 2.6A 5V 13W

• Need 2.6 Amps for 10 minutes

Determination of Battery:

• 2.6 𝐴 ∗ 10 𝑚𝑖𝑛 ∗1 ℎ𝑟

60 𝑚𝑖𝑛= 433 𝑚𝐴ℎ𝑟

• Need at least 5V • Chosen Battery: 7.2 V, 1.15Ah , Nickel Metal

Hydride Battery

Chosen Battery: Nickel Metal Hydride

Current Draw Calculation:


Voltage Regulation

• Two voltage regulators

• DC-DC Switching Regulator for camera (more efficient than LDO, has noise)

• Low Dropout Regulator for BeagleBone and Ultrasonic (Smooth voltage with 0.35V dropout at 1.5A allows for increased performance)

7.2V, 1.15 Ah, Nickel Metal

Hydride Battery

Quadcoptor Battery, 11.1V,

4.2 Ah LiPo

DC-DC Switching Regulator

APM Power Module

Low Dropout Regulator

Time of Flight Camera

BeagleBone Black

Ultrasonic Sensor

APM Autopilot

Max 10V, 1A 5V

5V

Max 40V, 3A


Thermal Analysis

ϴJC = 3°C/W

Out = 5V, I ≈ 1A

In = 7.2V, I ≈ 1A

Tjmax = 125° C

The temperature at the junction between circuit and mount; TJmax = 125 ° C The power dissipated, PD, from the regulator is calculated using

𝑃𝐷 = 𝑉𝑖𝑛 − 𝑉𝑜𝑢𝑡 ∗ 𝐼 = 2.2𝑉 ∗ 1𝐴 = 2.2𝑊

• Max ambient temperature, TAmax, can be solved for using

𝑇𝐴𝑚𝑎𝑥 = 𝑇𝐽𝑚𝑎𝑥 − 𝜃𝐽𝐴 + 𝜃𝐽𝐶 ∗ 𝑃𝐷

Where • ϴJA = Junction to ambient thermal resistance

• ϴJC = Junction to case thermal resistance From this, the TAmax the circuit can handle is 56°C, 35°C above ambient operating condition for this circuit

Junction

Heat Sync used for dissipation (ϴJA = 28°C/W)

LDO Voltage Regulator


Design Requirement 5 All components shall be capable of integrating with appropriate connections and protocols to transfer data


Data Handling

Argos P100 Camera: • Get 3D coordinates from the current frame • 3D Coordinates are organized as iterations of x, y, z float values

120 ∗ 160[𝑝𝑖𝑥𝑒𝑙𝑠/𝑓𝑟𝑎𝑚] ∗ 3[𝑎𝑑𝑑𝑟𝑒𝑠𝑠𝑒𝑠/𝑝𝑖𝑥𝑒𝑙] ∗ 32[𝑏𝑖𝑡𝑠/𝑎𝑑𝑑𝑟𝑒𝑠𝑠] ∗ 40[𝑓𝑝𝑠]

= 73.7 Mbits/s

Ultrasonic Sensor: • Serial data sent is 9600 baud, with 8 data bits, no parity, and one stop bit • Can configure the UART ports to operate at same rate with same configuration • Sends 40 bytes every second, ASCII ‘R’, followed by three numbers

APM 2.6 Autopilot • USB 2.0 data sent at a baud rate of 115200 • Will be plugged into the second port of the USB hub • Sends a MAVLink packet with a maximum of 256 bytes at 100 Hz


Camera Data Output Format

Data Handling


Design Requirement 6 Scout shall be capable of controlled hovering and maneuvering within ±6cm of a commanded position


Relation Between Force and Orientation

𝐹𝑚1,2 𝐹𝑚3,4

𝐹𝑚5,6 𝐹𝑚7,8

𝐹𝐺

𝐼𝑥

𝐼𝑧

𝐼𝑦

𝐹𝑇 𝑏 =00−𝑇

𝑇 ≡ 𝐹𝑚𝑖

8

𝑖=1

𝐹𝐺 𝐼 =00

𝑀𝑠𝑐𝑜𝑢𝑡 ∗ 𝑔

𝐵𝑦

𝐵𝑧

𝑀𝑠𝑐𝑜𝑢𝑡

𝐹𝑇


𝐵𝑥

−𝜃

Relation Between Force and Orientation

𝐹𝐺

𝐼𝑥

𝐼𝑧

𝐼𝑦

𝐹𝑇 𝐼𝑥

𝐹𝑇

−𝐼 𝑧

−𝐼𝑧

𝐹𝐺

𝐹𝑠𝑐𝑜𝑢𝑡 𝐼 = 𝑅𝑏/𝑖 𝐹𝑇 𝑏 + 𝐹𝐺 𝐼

𝑅𝑏/𝑖 = 𝑅3 𝜓 𝑅2 𝜃 𝑅1 𝜙

𝜓 ≡ 𝑦𝑎𝑤 𝑎𝑛𝑔𝑙𝑒

𝜙 ≡ 𝑟𝑜𝑙𝑙 𝑎𝑛𝑔𝑙𝑒 𝜃 ≡ 𝑝𝑖𝑡𝑐ℎ 𝑎𝑛𝑔𝑙𝑒

𝐹𝑥𝐹𝑦𝐹𝑧

=

−𝑇(𝑠𝑖𝑛𝜙𝑠𝑖𝑛𝜓 + 𝑐𝑜𝑠𝜙𝑐𝑜𝑠𝜓𝑠𝑖𝑛𝜃)𝑇(𝑐𝑜𝑠𝜓𝑠𝑖𝑛𝜙 − 𝑐𝑜𝑠𝜃𝑠𝑖𝑛𝜓𝑠𝑖𝑛𝜃)

𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡 − 𝑇𝑐𝑜𝑠𝜙𝑐𝑜𝑠𝜃

Small Angle Linearization: 𝒄𝒐𝒔𝜽 ≅ 𝟏, 𝒔𝒊𝒏𝜽 ≅ 𝜽, 𝜽𝟐 ≅ 𝟎 𝐹𝑥𝐹𝑦𝐹𝑧

≅−𝑇𝜃𝑇𝜙

𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡 − 𝑇= 𝑀𝑠𝑐𝑜𝑢𝑡

𝑥 𝑦 𝑧 𝐼


Altitude Control Block Diagram

𝑍𝑑 +

-

𝐸 𝐶(𝑠) 𝑀𝑠𝑐𝑜𝑢𝑡

+ +

𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡

−𝑇𝑑𝑒𝑠𝑖𝑟𝑒𝑑

+

𝑍 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 −𝑻 + 𝒈 ∗𝑴𝒔𝒄𝒐𝒖𝒕 1

𝑀𝑠𝑐𝑜𝑢𝑡𝑠2

-

𝑍𝑑 + 𝐸 𝐶(𝑠)

𝑍 𝑑𝑒𝑠𝑖𝑟𝑒𝑑

-

1

𝑠2

𝑍𝑎𝑐𝑡

𝑍𝑎𝑐𝑡

𝑍𝑎𝑐𝑡

−𝑇𝑑𝑒𝑠𝑖𝑟𝑒𝑑 = 𝑀𝑠𝑐𝑜𝑢𝑡𝑍 𝑑 −𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡 𝑍 = 𝑍𝑑 1

𝑠2= −𝑇 + 𝑔 ∗ 𝑀𝑆𝑐𝑜𝑢𝑡

1

𝑠2𝑀𝑠𝑐𝑜𝑢𝑡


Controller Design

Bode Plots of Plant Transfer Function, 𝑮(𝒔)

• Controller must add phase for system to be stable

Mag

nit

ud

e [d

B]

Ph

ase

[d

egr

ee

]

12/2/2013 Aerospace Engineering Sciences - Scout 37

Controller Design

Bode Plots of Loop Transfer Function, 𝑳 𝒔 = 𝑪 𝒔 𝑮(𝒔)

Lead Controller: 𝑪 𝒔 =𝟖.𝟕𝟏𝟕𝟑𝒔+𝟓

𝟎.𝟎𝟏𝟒𝟓𝒔+𝟏→ 𝑷𝒉𝒂𝒔𝒆 𝑴𝒂𝒓𝒈𝒊𝒏 = 𝟕𝟗° 𝒂𝒕 𝝎𝒄𝒓𝒐𝒔𝒔𝒐𝒗𝒆𝒓 ≅ 𝟏𝑯𝒛

Mag

nit

ud

e [

dB

] P

has

e [

de

gre

e]


Controller Performance-No Command Saturation • Commanded angles and

thrust passed into full non-linear force equations

• Violation of small angle

linearization yields poor controller performance

• Solution: Add limits to what angles and thrust can be requested


Controller Performance- Saturation


𝜃𝑚𝑎𝑥 = 10° 𝑇𝑚𝑎𝑥 = 2𝑚𝑔

Satisfying Control within ±6cm

Max Thrust Max Angle Max X Discrepancy Max Y Discrepancy Max Z Discrepancy

3𝑚𝑔 45° 4.98 cm 1.51 cm 10.34 cm

3𝑚𝑔 10 ° 0.06 cm 0.06 cm 0.88 cm

2𝑚𝑔 45 ° 3.75 cm 1.00 cm 7.60 cm

2𝑚𝑔 30 ° 1.38 cm 0.35 cm 4.08 cm

2𝑚𝑔 20° 0.47 cm 0.08 cm 2.13 cm

2𝑚𝑔 10° 0.07 cm 0.05 cm 0.87 cm

1.5𝑚𝑔 20 ° 0.43 cm 0.11 cm 1.95 cm

Discrepancies Evaluated For Unit Step in All Directions

Controls Position to Within ±3cm

Controls Position to Within ±6cm

Does Not Control Position to Within ±6cm


Design Requirement 7 Scout shall be able to detect and maneuver through the doorway while adhering to the positioning and control


Camera Data Door Searching


Data Processing

1

2

3

4

5

0

50

100

150

200

0

20

40

60

80

100

120

magnitudehorizontal axis

vert

ical axis

• Remove the values that show up at minimum range (corresponding to maximum range of the Camera)


Risk Analysis

Risk Summary

All important risks listed for each subsystem Probability and impact of occurrence values specified (From 1 to 5) Risk matrix created of Impact vs. Probability


Risk Matrix

Risk Mitigation Techniques

3. APM being capable of satisfying positional requirements

- Decrease speed - Verify that the calibration is optimal

4. Gyroscopic Drift - Determine orientation from camera data - Test gyroscopic drift over time to counteract

7. Moment of Inertia variations with mounting

- Design mounting to produce minimal changes in moment of inertia

- Ballast Scout to reduce mounting effects

9. Rotors causing ultrasonic sensor errors

- Create shielding for the ultrasonic sensor - Propeller low frequency filtering

10. BeagleBone Black Processing capabilities

- Decrease the number of points analyzed from camera data

Impact vs. Probability

Risk Off Ramp

3. APM being capable of satisfying positional requirements

- Purchase another autopilot with a greater accuracy

4. Gyroscopic Drift - Purchase gyroscopes with reduced drift specifications

7. Moment of Inertia variations with mounting

- Redesign mounting schematic

9. Rotors causing ultrasonic sensor errors - Alternative mounting position for ultrasonic sensor - Alternative sensor (2D laser)

10. BeagleBone Black Processing capabilities

- Process data off-board and then transmit


Medium (3)

Verification and Validation

Testing Schedule


Facilities

Facility Description Contact

RECUV Indoor Flying Lab

Team Meeting and Testing Location

Professor Frew

Electronics Lab Electronic Equipment and Tools Trudy Schwartz and Tim May

AES Machine Shop Mounting Fabrication Location Matt Rhode

ITLL Additional Machine Shop, Electronic Equipment, Access to SolidWorks and Altium

Trudy Schwartz and Matt Rhode

Visions Lab ANSYS and SolidWorks Access Aerospace Department


Validate SCOUT can Successfully Perform Doorway Detection and

Navigation Mission

Verify SCOUT can Navigate Through

a Doorway

Verify SCOUT can Autonomously Maintain Trim

Condition

Mission Tests

Verify Autopilot is Flight Ready

Verification of Successful Integration of Flight Ready Subsystems, Creating

SCOUT

Verify Sensor Suite is Flight Ready

Verify Control System is Flight Ready

Verify Mounting is Flight Ready

Verify SCOUT can Successfully

Perform Doorway Searching Mission


Test ability of sensors to dynamically detect door/ground with developed code when

mounted to multicopter and flown manually in RECUV Test Facility

Breadboard circuit, ensure devices receive proper

voltage/current

Flight Ready Sensor Suite

Verify sensors return expected range data

Test sensors on PCB, ensure correct data is sent to control

system at appropriate rate

Phase 1

Phase 2

Phase 3


RC Controller

Ultrasonic Sensor FOV

SCOUT with Sensors

T.O.F Camera FOV

VICON PC

Safety Netting

Wall Door

Compare Vicon measurements and sensor measurements


Flight ready Mechanical Mounting

Run through throttle settings and determine amplitude

and frequency of base excitation

Verify frequency response steady state magnification

factor from SolidWorks

Determine response steady state magnification factor of

mounts

Test mounting on multicopter with dummy masses, verify

developed model is accurate

Verify oscillations produce minimal discrepancy from multicopter location with

components added

Phase 1

Phase 3

Phase 2

Verify the center of gravity for electrical components and

multicopter


Auto Pilot is Flight Ready

Characterize Tuned Autopilot Tilt Dynamics

Verify Autopilot can be Commanded Via MAVLink

Protocol

Tune Autopilot PID Gains to Achieve Desirable

Performance

Characterize Autopilot IMU Sensors for

Performance

Verify Autopilot has Baseline Functionality

Phase 1

Phase 2

Phase 3


Purpose:

• Check basic sensor functionality

• Characterize Gyroscopic Drift

• Characterize Error in Accelerometer

Laptop Running APM Mission Planner

APM 2.6

Characterize Autopilot IMU Sensor for Performance

USB to microUSB Cable

Testing Procedure 1. Establish connection between mission planner and APM , ensuring the APM is laying on a flat surface

2. Begin Logging IMU data via the Mission Planner Command Line Interface (CLI) ‘test’, and ‘imu’ Commands

3. Extract IMU data from dataflash and telemetry logs

4. Examine IMU data and calculate drift rate of gyros


Verify Sensor Data Can be Processed, and Commands Sent,

at Sufficient Rates

Control System Is Flight Ready

Verify That the Flight Ready Autopilot Receives Correct Commands From the B.B.B

Verify that Control System Sends the Proper Autopilot Commands,

Given Current Sensor Data and Control Laws

Verify Algorithms Developed for Sensor Manipulation Can

Function Onboard the B.B.B, using Actual Sensors

B.B.B = BeagleBone Black

Verify Final Control Laws Can Function Onboard the

B.B.B

Verify Sensor Suite Signals Can Be Read By The B.B.B

Verify That Code Developed in MATLAB Can Obtain

Same Functionality When Ported to C

Phase 1

Phase 2

Phase 3


Verification and Validation

Dr. Ryan Starkey Faculty Mentor

Dr. Eric Frew Customer (RECUV)

CFO Gavin Montgomery

Testing/Safety Austin Anderson

Systems Marcell Smalley

Project Manager Geoff Inge

Software Mark Onorato

Electrical Ethan Long

Manufacturing Suresh Ratnam

Mechanical Tyler Shea

Controls Eddy Scott


Work Breakdown Structure

Software Electrical Manufacturing Mechanical Controls

1. Outer Control Loop Block Diagram

1. Simulink model of sensor data acq. and processing

1. Breadboard basic circuits

1. CAD Models a. Quadcopter b. Sensors c. Mounting

1. Mounting Plate Fabrication

Controls Test Reports: MAVLink Command

Verification, Dynamics Characterization,

Software Test Reports: Data Processing

Speed, Proper Data Signal (receive/send),

Code Startup Test

Electrical Test Reports: Serial Analyzer,

Flight Data Verification

Mechanical Test Reports: Vibration (Shake-

Table/SolidWorks), CG – balance confirmation

2. Flight software suite for BBB

3. Sim. vs flight performance comparison code

Scout

2. Simulink control software

2. Electrical circuit diagram

3. PCB design diagram

4. Printed PCB

2. CG Analysis Code

3. MOI Analysis Code

2. Testing wall/door materials manifest

3. Testing wall/door construction



Cost Breakdown- Main Budget

Item Cost

Single Board Computer $45

Time of Flight Camera $1140

Ultrasonic Sensor $35

Electronics $100

Mounting $100

Software/Controls $50

Testing/Safety $300

Total $1770

Margin $3230


Cost Breakdown- Vehicle Platform

Product Cost

RTF X8 Quadcopter $929.00

APM 2.6 Autopilot (Included)

Replacement Kit $114.99

2 Additional Batteries $102.99

Telemetry Kit $99.99

Total $1246.97

Margin $1753.03


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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]

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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]

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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]


References

https://www.mysick.com/ecat.aspx?go=FinderSearch&Cat=Gus&At=Fa&Cult=English&FamilyID=344&Category=Produktfinder&Selections=53789




http://www.all-battery.com/SamsungLi-Ion18650_7.4V_2800mAhwithPCM-31444.aspx







http://beagleboard.org/Products/BeagleBone Black

http://www.hokuyo-aut.jp/02sensor/07scanner/download/products/urg-04lx-ug01/







http://www.maxbotix.com/Ultrasonic_Sensors/MB1043.htm

http://store.3drobotics.com/products/apm-3dr-x8-rtf







http://store.3drobotics.com/products/apm-2-6-kit-1









http://www.ghoststop.com/Laser-Grid-GS1-p/laser-lasergrid-gs1.htm











http://www.thorlabs.us/NewGroupPage9.cfm?ObjectGroup_ID=3880&

http://www.youtube.com/watch?v=cdS6Cy5aOvk

Questions?


Appendix


Functional Objectives Summary

Functional Objectives

FO1 Measure relative position to wall/doorframe/ground

FO2 Mount sensor suite to multicopter

FO3 Sensor suite and control system interface

FO4 Scout shall maintain controlled flight

FO5 The system (Scout) shall maneuver through a doorway autonomously

FO6 The sensor suite and multicopter shall have an endurance of 10 minutes


Timing

APM (100 Hz)

Camera (40 Hz)

Ultrasound (10 Hz)

.1s

New Camera Data New Sonar Data

•APM expects inputs at 100 Hz •While new data is not produced, the old input commands will be sent

•1 or 2 cycles with the same input to APM

Mission Simulation Model Summary

- Simulink Model that allows user to define Scout’s initial position and orientation

- The model will simulate sensor data, interpret this data, and use control logic to motion within the user specified flight environment Steps for each Function:

1. Allows the user to create a flight environment (walls and doorways) and specify initial position and orientation within environment

2. Mimics Scout’s sensor data with the specified initial conditions

3. Takes sensor data and converts it into Scout’s relative position within environment

4. Takes relative position data and computes desired state of Scout for mission success

5. Takes desired state and calculates roll rate, pitch rate, yaw rate, rate of climb, and throttle required to get to desired state

6. Mimics APM 2.6 autopilot software with given desired inputs that will output new aircraft state

7. Stores flight data for RECUV indoor flying lab comparison


Equations of Motion

𝐹𝑠𝑐𝑜𝑢𝑡 𝐼 = 𝑅𝑏/𝑖 𝐹𝑇 𝑏 + 𝐹𝐺 𝐼


=

−𝑇(𝑠𝑖𝑛𝜙𝑠𝑖𝑛𝜓 + 𝑐𝑜𝑠𝜙𝑐𝑜𝑠𝜓𝑠𝑖𝑛𝜃)𝑇(𝑐𝑜𝑠𝜓𝑠𝑖𝑛𝜙 − 𝑐𝑜𝑠𝜃𝑠𝑖𝑛𝜓𝑠𝑖𝑛𝜃)

𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡 − 𝑇𝑐𝑜𝑠𝜙𝑐𝑜𝑠𝜃

Small Angle Linearization: 𝒄𝒐𝒔𝜽 ≅ 𝜽, 𝒔𝒊𝒏𝜽 ≅ 𝜽, 𝜽𝟐 ≅ 𝟎


≅−𝑇𝜃𝑇𝜙

𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡 − 𝑇= 𝑀𝑠𝑐𝑜𝑢𝑡

𝑥 𝑦 𝑧 𝐼

𝑥𝑦𝑧 𝐼

=1

𝑠2𝑀𝑠𝑐𝑜𝑢𝑡

−𝑇𝜃𝑇𝜙

𝑔 ∗ 𝑀𝑠𝑐𝑜𝑢𝑡 − 𝑇

𝐿𝑎𝑝𝑙𝑎𝑐𝑒 𝑇𝑟𝑎𝑛𝑠𝑓𝑜𝑟𝑚:

Can now calculate 𝑻,𝝓, 𝒂𝒏𝒅 𝜽 given a desired inertial acceleration

Using 𝑻,𝝓, 𝒂𝒏𝒅 𝜽; 𝐭𝐡𝐞 𝐫𝐞𝐬𝐮𝐥𝐭𝐢𝐧𝐠 𝐜𝐡𝐚𝐧𝐠𝐞 𝐢𝐧 𝐢𝐧𝐞𝐫𝐭𝐢𝐚𝐥 𝐩𝐨𝐬𝐢𝐭𝐢𝐨𝐧 𝐜𝐚𝐧 𝐛𝐞 𝐟𝐨𝐮𝐧𝐝


𝐷𝑟𝑎𝑤 𝐸𝑛𝑣

-

𝑃𝑑 𝑆𝑒𝑛𝑠𝑜𝑟𝑠 𝑃𝑟𝑜𝑐𝑒𝑠𝑠𝑖𝑛𝑔

+

𝑃𝑎𝑐𝑡𝑢𝑎𝑙

𝑃 =

𝑥𝑦𝑧𝜙𝜃𝜓

Draw Env Draws the room with Scout at a given state Sensors Mimics camera & ultrasonic readings (with errors) Processing Carries out logic algorithm for Scout Plant Model Simplified Non-linear dynamics of quad

𝑃𝑙𝑎𝑛𝑡 𝑀𝑜𝑑𝑒𝑙

User input IC

𝑜𝑛𝑒 𝑡𝑖𝑚𝑒

𝑃𝑒


Future Consideration-Incorporate Unmolded Dynamics


Search for Door

Initialize

Door detected

?

Final approach

Trim Conditioner

Yes

No

Power on

Trim?

Yes

No


Check signals from camera, ultrasonic & APM (Gyros)

Set flag (error indicator)

Abort mission & shutdown

Altitude Control

Log error data

Bad

Good

Wall Detect

Perpendicular Control

Initialize


Is height measurement

1m ±6 𝑐𝑚

Continue

Set Z desired to be 1m for the controller

No

Yes

Yes

Altitude Control


Camera detects wall?

Increment yaw (2𝑜)

Continue

No

Yes No Camera detects

wall within 3600 yaw?

Yes

Power down

Wall Detect


Is SCOUT perpendicular

to wall?

Increment yaw (2𝑜)

Continue

No

Yes

Perpendicular Block


Trim Conditioner

Altitude Block

Distance Block

Perpendicular Block

Continue


Distance Block

Is SCOUT 1m ±

6𝑐𝑚 from the wall?

Set x desired to

be 1m for controller

Continue

No

Yes


Search for Door

Move to the right while perpendicular to wall

(Increment y desired by X m)

Stop marker

detected?

Continue moving until discontinuity in camera

data is detected

Change direction and increment y desired by X m

Yes

Continue


Final Approach

Position center to the doorframe

Set x desired to be 3m

Power down


Verify Autopilot Command via MAVLINK Protocol Purpose:

1.To verify the APM2.6 could be controlled by the BeagleBone Black

Laptop running Ubuntu with MAVLink Driver

USB Connection

APM 2.6

Procedure 1. Remove propellers from the RTF X8 2. Install MAVLink driver on the laptop 3. Run “MAVLINK_MSG_ID_SET_ROLL_PITCH_YAW_THRUST” to set required thrust for the

motors 4. Observe motor response

RTF X8


Data Processing Risk

RAM: • 512MB of RAM and 2GB of eMMC flash from which you can run Ubuntu • 512 MB RAM can store 4,294,967,296 bits • Need to store approximately 73,700,000 bits/s

Processing: • Running Linux in the background makes it difficult to determine processing

time. • Code has not been generated in order to determine processing time

Off Ramps: • If fps are reduced to 10 fps number of bits to be processed decreases by 25% • Can also reduce the number of pixels processed

Gyro Drift

• Error associated with yaw angles from gyro integration.

• Possible solution is by locking onto the wall (Staying perpendicular)

• MPU-6000 Six-Axis (Gyro + Accelerometer) MEMS

• ± 2% for deviation from 25𝑜


Top-Level Functional Req.’s of Mounting • 1. Space and Visibility of sensors

• 1.1 Total mounting surface provides enough room for electrical components

• 1.2 Sensors placed on surfaces for maximum visibility

• 1.3 Standoffs provide clearance over multicopter’s structure (don’t interfere w/ x8 structure)

• 2. Satisfy weight budget • 2.1 Summation of masses of mounting surfaces, the standoffs and the electrical components must less than

1.5 kg

• 3. Negligible Discrepancy of C.G • 3.1 Surfaces do not disturb x-cg and z-cg components

• 3.2 Electrical component arrangements do not disturb x-cg and z-cg components

• 3.3 Standoffs do not disturb x-cg and z-cg components

• 3.4 Relative position of upper and lower configurations do not disturb y-cg component

• 4. Negligible Discrepancy of craft’s cross moments of inertia

• 4.1 Surfaces induce zero cross-sectional moments of inertia

• 4.2 Sensor placement induce zero cross-sectional moments of inertia

• 4.3 Standoff placement do not induce non-zero cross-sectional moments of inertia

• 5. Support Electrical Components

• Surface supports components without failing due to static and dynamic loading

• Standoffs support surfaces without failing

• 6. Dampen Adverse Frequencies

• Dampening device attenuates vibration frequencies imposed by multicopter’s powerplant that would damage sensors otherwise.


Structural Integrity

• Approximated Plates as beams with stress due both to shear and bending moments

TOP PLATE:

Bottom Plate:


𝐼𝑧𝑧 = 1

12𝜔𝑡3 𝑦 =

𝑡

2

𝑀𝑧𝑧 =𝑊𝑏𝑜𝑡𝑡𝑜𝑚

2

𝐿

2− 𝑟 −

1

8(𝑊𝑝𝑙𝑎𝑡𝑒𝐿 +𝑊𝑏𝑎𝑡𝑡𝐿𝑏𝑎𝑡𝑡 +𝑊𝑏𝑎𝑙𝑙𝐿𝑏𝑎𝑙𝑙 +𝑊𝑚𝑖𝑐𝑟𝑜𝐿𝑚𝑖𝑐𝑟𝑜 +𝑊𝑢𝑙𝑡𝑟𝑎𝐿𝑢𝑙𝑡𝑟𝑎)

𝑀𝑥𝑥 = 𝑊𝑏𝑜𝑡𝑡𝑜𝑚

2

𝜔

2− 𝑟 − 𝑊𝑚𝑖𝑐𝑟𝑜

𝜔 − 𝜔𝑚𝑖𝑐𝑟𝑜

2− 2 ∗ 𝑟 −

1

8𝑊𝑝𝑙𝑎𝑡𝑒𝜔 −

1

4𝑊𝑢𝑙𝑡𝑟𝑎𝜔𝑢𝑙𝑡𝑟𝑎 −

1

8𝑊𝑏𝑎𝑡𝑡𝜔𝑏𝑎𝑡𝑡

𝐼𝑥𝑥 = 1

12𝐿𝑡3

𝜏𝑥𝑦 = 𝜏𝑥𝑧 = 𝜏𝑧𝑦 = 0


Stand-offs:

Minimum Factor of Safety

• 3D Mohr’s Circle

• Minimum Factor of safety was found to be associated with lower plate FS =128.68

Stand Off Mounting

Shake Table

Dummy Mass

Ballast

Accelerometer

y(t)

yb(t)


Testing Safety and Risk Considerations

• To mitigate risk of injury during operation of multicopter, 3 safety netting sheets (17ft x 25ft) will be installed to contain the flight test area

• If SCOUT loses control, RC controller will be used to override autopilot and regain control • This can be done by setting various 2 “flight modes” in the APM, one for

autonomous flight, and one for manual

RC Controller

Safety Netting

Wall Door


Documents

Critical Design Review - colorado.edu · Critical Design Review Austin Anderson Suresh Ratnam Geoff Inge Eddy Scott Ethan Long Tyler Shea ... CDE 4 All components must be within the