Safety Motion Detector

Safety Motion DetectorFinal PresentationSenior Design IDecember 1, 20111Safety Motion Detector Team

Alden StennisJason SmithProgrammingSensorsGeoff JakinsPCB DesignWebsitePCB DesignSensorsDr. DonohoeFaculty Advisor

Electrical EngineerElectrical EngineerProgrammingSensorsElectrical EngineerJustin ParkerElectrical Engineer

2OutlineProblemSolutionSystem OverviewConstraintsTechnicalPracticalEvaluationSenior Design IIReferences3Problem and Solution4ProblemUtility workers alone are in the field getting injured and are unable to receive help within a reasonable amount of time.There are approximately 600 deaths yearly from falling accidents in the work field.

5

SolutionSafety Motion DetectorWrist device monitors users movementSignals the base station when no movement is detected

6System Overview(Wrist Device)Motion SensorPower SupplyTransceiverMicrocontrollerInterface7Technical and Practical Constraints8Technical Constraints

ConstraintDescriptionNotificationsVisual displays must indicate the safety status based on the users movement. Transmission DistanceThe base station must communicate data with the detection unit up to 200 feet. Battery LifeThe batteries must last for at least 24 hours.Temperature RangeThe SMD must withstand temperatures in the range of -40 to 185 F.

Motion Detector SensitivityMinimal motion, acceleration between -1.5 and +1.5 g0 with minimum increments of 0.1 g0. must be detected along one or more axes.

9Practical ConstraintsTypeNameDescriptionManufacturabilitySizeThe dimensions must be no larger than 3 wide, 3long and 1.5 high

SustainabilityRuggednessThe wearable device must be capable of withstanding everyday use in the field.

10ManufacturabilityDevice must be small in sizeDevice will be no larger than 3 wide, 3 long, and 1.5 highMust be wrist wearable to increase efficiencyMust not interfere with the users work

11SustainabilityMust withstand everyday use in the fieldWater resistantFunction properly in hot or cold weather conditionsDevice encasement durabilityStrong enough to handle accidental impact

12Evaluation13Wrist Device

Wrist Device

MicrocontrollerWrist Device

AccelerometerWrist Device

NotificationsWrist Device

TransceiverBase Station

Base Station

TransceiverBase Station

MicrocontrollerBase Station

NotificationsAccelerationWrist Device: Standstill

While the wrist device is at a standstill, the voltage output of each axis remains constant. The voltage of the z-axis is higher because of gravity pushing down on the top of the accelerometer.23AccelerationWrist Device: Free Fall

The highlighted values represent the wrist device in freefall. The Z-axis voltages were graphically plotted to show constant acceleration.24Range Testing

A range test was done by separating the wrist device from the base station in 50 ft increments to check for proper functionality. Once the constraint of 200 ft was met, additional tests were done in increments of 10 ft to measure the maximum range.25Out of Range TestIf the user is out of range, the notification lights will blink repeatedly. This will continue untilthe devices are back in range to communicate with each other.

26Battery LifeCurrent Draw - Microcontroller

Awake Current: 1.173 mA Sleep Current: 0.034 mA27Battery LifeCurrent Draw - Transceiver

Awake Current: 49.447 mASleep Current: 0.033 mA28Battery LifeCurrent Draw Accelerometer

Sleep and Awake Current: 0.268 mA29Battery LifeCurrent Draw Total CircuitAwake Current: 64.327 mA

Sleep Current: 5.365 mA30Actual Battery LifeDeviceAwake Current (mA)Sleep Current (mA)Microcontroller 1.1730.034Accelerometer 0.268N/ATransceiver49.4470.033Total64.3275.365Time Asleep(s)Time Awake(s)Sleep/Wake Cycle(s)Average Current(mA)Battery Life(hours)Battery Life(days)0606064.33046.631.948.51.51014.205211.198.8031Senior Design II Goals32Senior Design II GoalsImprove Battery LifePCB DesignBuild Enclosure and PackageImprove Software Test Final Design33Timeline for Senior Design IAugustSeptemberOctoberNovemberResearchOrdering PartsDesign

ProgrammingAnd ConstructionPrototype34Timeline for Senior Design IIJanuaryFebruaryMarchAprilPCB DesignSoftware RefinementPCB PopulatingTestingEnclosure35References[1] "Census of Fatal Occupational Injuries (CFOI) - Current and Revised Data." U.S. Bureau of Labor Statistics. Web. 07 Sept. 2011. .[2] Pic24FJ64GA102 [3] Pic24HJ32GP202< http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en530328>[4] AD22285-R2 < http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=AD22285-R2TR-ND>[5] MMA7660FCT < http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=MMA7660FCT+>[6] ADXL335 < http://www.sparkfun.com/products/9269>[7] How does ZigBee compare with other wireless standards? < http://www.stg.com/wireless/ZigBee_comp.html>[8] Xbee, Xbee Pro, Xbee Pro XSC < http://www.sparkfun.com/datasheets/Wireless/Zigbee/XBee-Datasheet.pdf> Page 5

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