TornadoTrakPreliminary Design Review

February, 2012

Kody MalloryAdam PrulhiereBruce DeakyneLuke TonnemanTrevor McDonald

The Research and Engineering Center for Unmanned Vehicles (RECUV) is a university, government, and industry partnership dedicated to the development and application of unmanned vehicle systems. RECUV research encompasses scientific experiments, commercial applications, mitigation of natural and man-made disasters, security, and national defense.

RECUV Mission

Photo Courtesy of Jack Elston

Photo Courtesy of Jack Elston

The TornadoTrak system will be capable of maintaining contact with an unmanned aerial vehicle (UAV) as it flies its route in dangerous and unstable weather conditions.

Mission Statement

Operate at 900 MHz Omni-directional and electronic beam-

steering modes Autonomous and manual input beam-

steering Interface with existing architecture Fit on roof of chase van

Project Objectives

Primary Receive desired angle from Mobile Control Station

(MCS) and steer relative to van orientation Secondary

Combine GPS data from UAV and MCS to determine desired angle

Tertiary Use signal quality feedback from transceiver to

finely adjust angle using control law

Goals

Block Diagram

8 Element Uniform Circular Array Half Wavelength Radius Radiating Element: Monopole

Phased Array

900 MHz Monopole Antenna SMA Connection Up to 10 W 50 Ω Cheap Small Light-Weight Durable

Radiating Element

Microhard MHX-910 Transceiver

Transceiver

Transmit Network

Receive Network

Controller Antennas

Block Overview

Beam Forming Network

Divider

Phase Shifter Amplifier

Control Block

Antenna

T/R

Phase Shifter

T/R

Summer

Purpose:To relay amplitude and phase shifted signal from source to 8 separate antennas

Parts T/R Switch Phase Shifters Amplifiers Limiter

DividerPhase Shifter

Amplifier T/RAmplifier

Antenna

T/R

Transmit Network

Purpose: Relay and phase shift data from antenna array to

base station Utilizes the internal amplifier of the MCS Parts:

Isolators (if required) T/R Switch Phase Shifters Summer

Receive Network

Summer

T/RPhase Shifter

Antenna

T/R

JSPHS-100 Variable Phase Shifter 0-15V Voltage controlled 700-1000 MHz 180 degrees, 50 ohm

AD5582 Quad DAC 12 bit 0-15V output voltage Read/Write Mode

Preliminary Component Selection

The microcontroller will interface with the MCS and UAV for gathering and processing the location and orientation information GPS from UAV Commands from MCS Control the phase shifters to steer beam. GPS and Magnetometer from MCS Communicate with Transceiver

Microcontroller

uC Accuracy 32 Bit FP unit

Timing requirement- control a 1 degree margin within 0.87 seconds Omni mode is enabled at ~1km UAV Speed=20m/s

GPIO=~30 Pins SCI communication

Design Consideration

uC

Transceiver

Quad DAC (x4) Phase

Shifter(x8)

Voltage

Phased Array

DAC Select [1:0]DAC Mode [3:0]

Command (USB/SCI)GPS/Magnetometer Data

DAC Read φ [11:0]

DAC φ Value[11:0]

TX Signal

AMP (x8)

Digital SignalAnalog Signal

RF Signal

Signal StrengthCommandRS232

RX Signal

TX Data (From MCS)

MCS

Phase Shifter

(x8)

TMS320F28035 32 bit 60MHz with floating point arithmetic unit SCI/SPI/I2C Interfaces 1.8/3.3v supply 45 GPIO pins

USB Interface FT232RL

Preliminary Component Selection

System will be powered by the MCS This is 120 V AC 60 Hz Converters need to rectify AC input voltage

to DC output voltage Need 1.8 V, 3.3 V to power ICs Also need 15 V for reference for DACs Will also need to monitor current, as too much

might damage some components

Power System

Will have two stages: Commercial rectifier, and then linear regulators Linear regulators will provide the needed voltages

Outputs will need to be monitored to control current output Outputs will additionally be fused to prevent

damaging current spikes Try to have isolation transformers between

different power stages Done to reduce interference from ground loops

Design Considerations

Special attention to the layout of the PCBs with RF traces Due to high frequency, could run into EMI and

coupling into the power and ground plane. Converters will have a separate PCB, and

power will be routed to each individual system Promotes modularity

Design for highest efficiency possible MCS does not have unlimited power

Design Considerations

Converter system, 15 V reference and 3.3 V,

1.8 V for ICs

DACs

Microcontroller,DACs,

Amplifiers, USB Interface

15 V reference

3.3 V, 1.8 V supply

Overview

120 V AC from MCS

Power System

120 V AC

Linear Regulators

Commercial rectifier

providing 15 V DC

Load

Capacitors– Mouser Electronics For bypass, decoupling and various other

purposes POWER SUPPLY EXT - CENB1010A1503B01

Supplies 12W 15V @ 0.8A Linear Technology LTC1844 Linear Regulator

Adjustable output voltages Coilcraft DA2303-AL Isolation Transformers

To minimize ground loops

Preliminary Component Selection

Interfacing

Magnetometer

Van Power

Serial Data

Power Systems

Microcontroller

Amplifiers / Phase

Shifters

Antenna

Requirements: Durable Weatherproof Lightweight

Materials: Plexiglass (Acrylic) Aluminum PVC

Fixture

Shielding

PCB

Antenna Ground Plane

Antenna Mount

Processor can’t keep up with UAV Reduce Tracking resolution and resort to Omni

mode further out USB Interface is non communicative

Revert to module made by Sparkfun and connect Feedback is not accurate enough

Resort to assuming correct response DAC accuracy

Risks and Mitigation

RF network error Calibrate in chamber and modify software

Reflection Matching network

Component noise Calibration

Signal Delay Transceiver settings

Risks and Mitigation

Might not be able to incorporate isolation transformers Redesign PCB to minimize ground loop size

Interference could be produced from the lines, traces on the PCBs Shielding

Risks and Mitigation

Modular System Easy repair in the field

Shielding between PCB and RF Beam Steering Failure

Switched beam high gain antenna

System Mitigation

Very little team CAD or fabrication experience Utilize colleagues in MechE

Adequate shielding RF power meter

Durability & Weight Safety margins

Fixture Risks and Mitigation

Schedule “Troubleshoot week” Reallocate resources as necessary Phase project

Working individual components

Project Mitigation

BudgetRF and Antenna Quantity Price Total Cost

Variable PhaseShifter 36 $26.95 $970.20

8 Way Power Splitter/Combiner 2 $138.95 $277.90

Fixed Gain Amplifier 8 $84.95 $679.60

T/R Switch 9 $56.95 $512.55

Monopole Antenna 8 $9.95 $79.60

RF Cables 52 $8.45 $439.40

RF Total $2,959.25

Budget Cont.

Embedded & Analog Quantity Price Total Cost

Microprocessor 1 $83.07 $83.07

DAC 4 $19.58 $78.32

Connector 1 $1.29 $1.29

USB-Serial 1 $6.99 $6.99

E&A Total $169.67

Budget Cont.Power Quantit

y Price Total Cost

PCBs 15 $30.00 $450.00

Filter Capacitors 20 $1.55 $1.55

Linear Regulators 3 $1.77 $5.31

Isolation Transformer 3 Sampled $0

Power Supply 1 $14.38 $14.38

Power Total $471.24

Budget Cont.Hardware Quantit

y Price Total Cost

Plexiglas 1 $110.00 $110.00

Mounting 1 $25.00 $25.00

Hardware 1 $50.00 $50.00

Aluminium Sheet 1 $40.00 $40.00

Poster 1 $50.00 $50.00

Misc. Total $275.00

Total Projected Cost $3,875.16

Anticipated Funding

Organization Amount

Undergraduate Research Opportunity

$1,000

Engineering Excellence Fund

$1,000

Research and Engineering Center for Unmanned

Vehicles

$5,000

Total $7,000

Task Kody Adam Luke Trevor Bruce

Control Algorithm P S

Comm SW P S

Power Board P S

Array Design P S

Beam Forming Network S P

Controller Board P S S

RF Boards P S S S

Mount/Structure S S S P

Sensor Interface S P

P=Primary S=Secondary

January 19 – March 1

February 23 – April 5

March 22 – May 3

RECUV, Professor B. Argrow, Jack Elston and Maciej Stachura

Joe Carey, Fidelity Comtech Brandon Gilles, First RF Professors E. Kuester, D. Filipovic Tom Brown, Sam Siewert Carissa Pocock, Robert Pomeroy, Jeries

Shihadeh

Acknowledgements