Easy On The Tini

Easy on the Tini Cell phone detector Bill Barker Carey Davis Ben Irwin Travis Majors

Description and Goals To create a robot that detects RF signals (cell phone signals) then moves toward the strongest signal. Notifies cell phone user about use in that area.

Outline of Approach Create a robot with two servo motors Fashion RF detecting antenna(s) on the robot chassis Mount IR sensors to aid robot movement Use display, lighting, sounds, etc. to deter cell phone use Design a microcontroller to interface the systems

Hardware Implementation Home Base

RF Beacon

RF Signal Detection

IR Object Detection

Microcontroller

Motor Controller Motor Feedback

Servo Motors

Data/ Programming interface

Signal Disruption

Implementation of Subsystems

The Robot Metal platform from previous project Two 9FGHD Ferrite Series ServoDisc Motors

Robot Movement Autonomous 

Object Detection 

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Infra-Red

Home Base Detection 

RF

Programmable Search Pattern 

Signal Detection Sweep

Identify and approach appropriate signal

Scenario #1

Signal Found

Scenario#2

No Signal Found

Signal Found Object Detected No Signal Found

IR Object Detection Sharp GP2D12 Analog output voltage Vcc-.3V to .6V based on distance from object 0cm to 80cm

The Motor 9FGHD Ferrite Series ServoDisc Motor Input voltage -12V to +12V Capable of 1.5 N-m continuous torque

Motor Drivers Microcontroller delivers signal voltage to drivers using PWM Driver performs DC/DC conversion to step up input signal voltage to -12V to +12V output motor voltage

Motor Encoders Encoders such as the HEDS-5500 mounted on each motor

Signal Detection

Robot Signal Detection Overview: This part of the robot will detect signals within the GSM frequency-band that will then be translated into data that will control the robots movement in pursuit of a detected strong signal. This will be done by the following devices:

Tuned directional antennas  RF signal intensity meter  Voltage processing component 

Tuned Directional Antennas This component will give directional ordination to the robot to pursue the signal. 

A Yagi antenna will be used to hone in on the signal. 

Antennas Specifications:

GSM: Uplink 890-915MHz and Downlink 935-960Mhz PCS band: 1.7-1.99 GHz

Directional Capability

Yagi VS Omni directional antennas

RF Signal Intensity Meter This simplified circuit will take the antenna’s RF signal as an input and will output a voltage that is proportional to the signal’s intensity.

Voltage Processing Component Feed measured voltage into the micro-controller’s A/D converter. Have the microcontroller only sample at what is realistic to match the motor’s encoder data. Store both RF intensity and robot direction data for a full revolution in on-board RAM. Find peak voltage within data and have robot return to this recorded direction.

Microcontroller Prototype Board for MSP430-F1611     

Multiple A/D converters Expanded RAM to 10K bytes for greater storage capacity PWM capabilities for motor control Good tools and easy debugging Cost effective solution of our application

Power Distribution

Power Distribution and Peripherals Voltage Variations 

Driver motors, Lights, Speakers, Sensors, Circuitry, Display screen

Voltage regulators or converters Recharging at “home”

Power Distribution and Peripherals-Battery 2 BP7-12 12 V 7Ah Batteries to power the robot 5.94” x 2.56” x 3.98” 6 lbs.

Disruption Handling

Disruption Handling Robot Modes 

Hospital Mode Robot looks for over any amount of time, suggesting a data transmission  Turn off your cell phone! 

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Silent Mode Robot looks for signal lasting for awhile, suggesting a call vs. a text message  Quiet your phone! 

Disruption Handling Disruption of Call LCD screen for message  Lights, sounds  Physically disrupt the call? 

Home Base

Home Base Robot will be able to autonomously return to a given “home base” for a variety of reasons: Battery charge level  Set time period  Called back by us 

Home Base Recharge Station RF “Beacon” Data Sync

Home Base –RF “Beacon” To call the robot home a signal within the robots detection bandwidth will be emitted. Constant frequency within range of detection device  Higher power to override cell phone signals. 

Same intelligence used to follow cell phone signals will be used find the home base.

Home Base-Programming Home Base will be used to reprogram different parameters of the robot such as: Search Pattern  Search Time 

Risks/Contingencies

Risk/Contingency #1 Risk: It might be impossible to legally physically disrupt the cell phone signal. Contingency: Robot will ask user to turn off phone via basic display/sounds.

Risk/Contingency #2 Risk: Difficulty to differentiate between cell phone signals and other RF signals. Contingency: Setup closed environment with little outside interference and use a strong set signal to test tracking ability.

Risk/Contingency #3 Risk: Complexity of artificial intelligence and automation. 

Object avoidance while tracking signal.

Contingency: Test in empty room to simplify coding.

Risk/Contingency #4 Risk: In areas that RF transmissions are not allowed, our home beacon will not suffice. Contingency: Program return path or remember path traveled in order to return home.

Scheduling, Costs, and Labor

Prelim Schedule

Milestones Milestone 1:Robot moves towards test signal Milestone 2:Programmable search parameters, IR object detection integration, home base construction complete Expo:Robot and home base fully functional

Cost Estimations

Thank you! ??Questions??