Slide 1

EcpE 492: Dec09-14 Engr 467: LABETIV_SP09 Henri Bai Steve Beckert Ian Moodie Mike Rau Matthew Nelson, Advisor John Basart, Advisor December 9, 2009 Slide 2 2 Slide 3 As real-world engineering becomes more complex and requires the skills of many disciplines, it is difficult to accurately simulate a design process in the classroom. Goals of LABET project: Design, build, test, and fly a semi-autonomous robotic balloon Incorporate knowledge and skills of multiple disciplines Provide platform where students from AeroE, MatE, ME, CprE and EE can work together to improve upon a similar product 3 Slide 4 LABET shall weigh less than 1.5 pounds LABET shall have minimum fly time of 20 minutes LABET shall have yaw control LABET shall have altitude control LABET shall have ability to traverse forward and backwards LABET shall have ability to be controlled wirelessly LABET shall have ability to land autonomously on a table from 4 meters above LABET shall have attachment point for 100g balloon 4 Slide 5 LABET should be aesthetically pleasing LABET design should be innovative LABET should be easy to control LABET should be completed with thorough documentation 5 Slide 6 Use as a promotional tool by client, SSCL Displayed during tours or events To be operated in Howe Hall atrium Flown indoors only 6 Slide 7 Processor PIC24FJ64GA004 Sensors 3-axis Accelerometer 2-axis Gyroscope Sonar Communication RF Transceiver Flight Control 2 Ducted Fans 4 Servo Motors Power 7.4 Volt Li-Ion Array 7 Slide 8 8 Slide 9 Two fan design Thin member design with cross member support Includes two cradle cross members for balloon attachment and support Includes two landing pad attachment cross members Two fans will be mounted using a bi-axial swivel ring 9 Slide 10 ABS Plastic Optimal strength to weight ratio Easy to cut and manipulate Proper flexibility for shock absorption though tough enough to prevent yielding IPS Corporation acrylic cement Specifically for ABS plastic Used to bond joints and laminate 2 ABS layers Plastic and Cement Supplier www.eplastics.com 10 Slide 11 Aircraft was over weight budget at initial flight Batteries purchased for LABET IV were larger than what was specified (40 grams more total) Analysis was conducted to determine points of interest Determined material could be removed from cross members, fan gimbles, and fan mounting arms to reduce weight Total weight reduction: 65 grams 11 Slide 12 12 Slide 13 Purpose Communicate between base station and aircraft Send aircraft movement commands Receive aircraft status messages Technical Detail Implemented in LABVIEW Control scheme uses XBOX360 Controller Messages received and sent asynchronously Messages are sent through serial port, which is transparently handled by RF for the physical layer 13 Slide 14 14 Slide 15 Poll Serial Check Data Poll Controller Data Send Serial Interface Bad Packet ? Parse Packet Yes, discard No Build Packet 15 Slide 16 Messages have the following format: Example of Movement Command: HeaderData LengthMessage TypeDataXOR 3Variable1 1 HeaderLengthMessage TypeData 0x19 0x28 0x3750x44Translation X Data XOR Translation YYaw CommandElevationCalculated 16 Slide 17 Interrupt Queues RF Receive Data Timers Periodically Send Status Message Poll Sensors Maintains Fan/Servo Positions Main Loop ( Control ) Unloads RF Queue Determines Desired Motion Control Algorithms Set Fan/Servo Positions 17 Slide 18 Fan/Servo Control Highest Priority Toggles GPIO to Create pulse, 1ms to 2ms On-Time Set by Control Algorithms Poll Sensors Medium Priority Reads ADC, Reads SPI Adjustable Frequency, 0.5 Hz to 20+ Hz Status Message Low Priority Sends Aircraft Status Message to Base Station 18 Slide 19 19 Base Station LABET Slide 20 Learn about PIC24FJ64GA004 Processor Configuration UART, SPI, ADC Timers, Interrupts PWM Generation Component Testing (Development Board) Accelerometer SPI Gyroscope/Sonar Analog, ADC Wireless Transceiver UART Fan/Servo Timers, PWM Generation 20 Slide 21 RC Aircraft Testing Component Integration Prototype Board Explorer 16 Development Board (PIC24FJ64GA004) 21 Slide 22 Creation of Error Signals 22 Slide 23 Error Signals -> EOMS -> Fans/Servos 23 Slide 24 24 Slide 25 25 Slide 26 26 * As of Dec 11 Slide 27 Matthew Nelson (Client, Advisor) Dr. John Bassart (Client, Advisor) Dr. Gregory Luecke (Controls advice) 27 Slide 28 28 Slide 29 Styrofoam/wood chassis Bent plies to provide landing support One large fixed, vertically mounted propeller to provide lift Servo attached to rudders for yaw control Controlled by computer Indoor use only 29 Slide 30 Carbon fiber chassis with plastic tubing Two fixed, vertically mounted motors Tail prop for yaw control Pitch control using servo and strings attached to balloon Controlled by computer using custom programming Indoor use only 30 Slide 31 Three vertically mounted motors Each provide 3 lbs of thrust (almost capable of lifting the device without a balloon) Built out of fiberglass and aluminum More durable chassis Indoor and outdoor use 31 Slide 32 Two fan design Thin member design with cross member support Includes two cradle cross members for balloon attachment and support Includes two landing pad attachment cross members Two fans will be mounted using a bi-axial swivel ring Will include electronic hardware mounts 32 Slide 33 Two fan design w/prop Lighter weight than three fan design Tube structure, easier to build Heavier than a thin member design Fore and Aft control similar to LABET II Three fan design Most stable design Tube structure, easier to build Most powerful Uses more power Heavier 33 Slide 34 Several designs considered and modeled in SolidWorks Two-fan, Cradle design chosen Best combination of weight, ease of manufacture and stability Full size prototype has been built 34 Slide 35 Balloon lifts 90% of weight Two fans are to provide: Lift for remaining 10% Thrust to ascend Total Fan Thrust = Aircraft weight*(0.10) Thrust Per Fan = Total Fan Thrust / 2 With a maximum weight of 680 grams (1.5 lbs), the minimum thrust provided by each fan is approximately 34 grams 35 Slide 36 Three fans from GWS were evaluated The chosen fan is the EDF 55-150 Pros: Variable thrust output from 32g to 152g Higher efficiency Lower operating voltage to hover Cons: Twice as heavy as the others Costs $4 more 36 Slide 37 Servos Employed to Provide Rotational Fan Motion 1 Servo Per Axis of Rotation Per Fan 4 Servo Motors Minimize Servo Weight/Cost; 9 g / 10$ 9 * (4) = 36 g, 36 g = 5.15% Weight Torque: 1. 2 kg.cm at 4.8 V Speed: 0.13 sec/60 Operated at 5 V Supply PWM Signal For Control PIC Directly to Servo 37 Slide 38 Measures Altitude for use During Autonomous Landing Ultrasonic Range Finder - Maxbotix LV-EZ1 3.3 V, 2 mA 42 k Hz with Read Rate 1/50 ms Distance: 1 cm 500 cm Analog Output Employed for System Integration Output 10 mV/inch Testing Full scale Range Temperature Effects Output Accuracy Available in SSCL 38 Slide 39 Invensense IDG-1215 3.0 V, 7mA Dual axis Integrated low-pass filters Auto zero function Integrated temperature sensor Rotation Rate = (Output Voltage VREF) / Sensitivity Implementation The Silicone Horizon Breakout Board On-board regulator On-board opAmp buffers Pads for passive components Right angle header 39 Slide 40 STMicroelectronics LIS3LV02DL 3.3 V, 0.8mA 3-axis, Digital sensor High (2g) and low (6g) sensitivity Output Registers: OUTX_L (LSB) and OUTX_H (MSB) Implementation STEVAL-MKI009V1 evaluation board Transforms the 16 pin land grid array (LGA) into a dual inline package (DIP) IC bus (CS, SCL, SDA) or the SPI bus (CS, SPC, SDI, SDO) 40 Slide 41 Lithium-Polymer 3.7 Volt Cells Requirements 7.4 Volts Max Discharge Rate: ~15 A Capacity: ~2200mAh Weight: