ECE 480 Design Team 6ECE 480 Design Team 6Lightweight Speed and Lightweight Speed and
Distance Sensor for Skiers Distance Sensor for Skiers and Snowboardersand Snowboarders
Michael Bekkala
Michael Blair
Michael Carpenter
Matthew Guibord
Abhinav Parvataneni
Facilitator: Dr. Shanker Balasubramaniam
AgendaAgenda
BackgroundBackground ObjectiveObjective Design SpecificationsDesign Specifications Potential SolutionsPotential Solutions Proposed SolutionProposed Solution Conceptual flowchart and HardwareConceptual flowchart and Hardware
Goal of Competitive SportsGoal of Competitive Sports
1)1) WinWin
2)2) Perform better than the competitionPerform better than the competition
3)3) Improve performanceImprove performance• Requires tracking of statisticsRequires tracking of statistics
Jump HigherJump Higher Run FasterRun Faster Hit HarderHit Harder
Bicycle SpeedometerBicycle Speedometer
Sensor mounts to wheel and frameSensor mounts to wheel and frame Counts time between Counts time between
wheel sensor passing wheel sensor passing
frame sensorframe sensor Calculates wheel speedCalculates wheel speed Forward speed is Forward speed is
proportional to rotation of wheelproportional to rotation of wheel
Nike Plus (Nike+)Nike Plus (Nike+)
Sensor placed in shoeSensor placed in shoe Determines how long pressure is Determines how long pressure is
applied to the footapplied to the foot The time that pressure isThe time that pressure is
applied is directly applied is directly
proportional to the proportional to the
runner’s speedrunner’s speed
ObjectiveObjective Design a speed and distance sensor for skiing and Design a speed and distance sensor for skiing and
snowboardingsnowboarding
Current Products:Current Products:• ExpensiveExpensive• InaccurateInaccurate• InconvenientInconvenient
Objective:Objective:• Greater accuracyGreater accuracy• Lower costLower cost• Improve functionalityImprove functionality
Design SpecificationsDesign Specifications SafetySafety
• Disable display while movingDisable display while moving FunctionalityFunctionality
• User definable auto shutdown timeUser definable auto shutdown time• PC interface for data reviewPC interface for data review• Ease of use in winter apparel Ease of use in winter apparel
PackagingPackaging• Operate at subzero temperature (-10°F)Operate at subzero temperature (-10°F)• Shock resistantShock resistant• WaterproofWaterproof• Weigh less than 2 lbsWeigh less than 2 lbs
Cost - less than $500Cost - less than $500
Potential SolutionsPotential Solutions
1)1) Relative PositioningRelative Positioning
2)2) Inertial Navigation System (INS)Inertial Navigation System (INS)
3)3) Global Positioning System (GPS)Global Positioning System (GPS)
4)4) Integration of INS and GPSIntegration of INS and GPS
1. Relative Positioning1. Relative Positioning
Transmitter locally placedTransmitter locally placed• Sends out signal to receiverSends out signal to receiver• More transmitters = Better accuracyMore transmitters = Better accuracy
Receiver gets signal fromReceiver gets signal from
transmittertransmitter• Calculates distance from Calculates distance from
transmittertransmitter• Derivative of distance = SpeedDerivative of distance = Speed
1. Relative Positioning1. Relative Positioning
Advantages:Advantages:• AccurateAccurate• ReliableReliable• Independent of external systemsIndependent of external systems
Disadvantages:Disadvantages:• ComplexComplex• Requires a locally placed transmitterRequires a locally placed transmitter• Relative position vs. absolute positionRelative position vs. absolute position
2. Inertial Navigation System2. Inertial Navigation System 3 Accelerometers3 Accelerometers
• Measure Linear AccelerationMeasure Linear Acceleration• X, Y, Z Directions X, Y, Z Directions • Integrate to get speed and distanceIntegrate to get speed and distance
3 Gyroscopes3 Gyroscopes• Measure Angular VelocityMeasure Angular Velocity• Pitch, Roll, YawPitch, Roll, Yaw• Integrate to get angularIntegrate to get angular
positionposition Coordinate conversionCoordinate conversion
• Body Frame to ECEFBody Frame to ECEF
2. Inertial Navigation System2. Inertial Navigation System
Advantages:Advantages:• Very accurate for short periods of timeVery accurate for short periods of time• Updates faster than GPSUpdates faster than GPS
Disadvantages:Disadvantages:• Requires at least 6 sensorsRequires at least 6 sensors• Susceptible to bias driftsSusceptible to bias drifts• Error increases over time (t^2)Error increases over time (t^2)• Requires initial conditionRequires initial condition
3. Global Positioning System3. Global Positioning System Receives time data from satellitesReceives time data from satellites
• Requires very accurate timingRequires very accurate timing• Atomic clocks on board satellitesAtomic clocks on board satellites
Triangulates positionTriangulates position• Uses distance fromUses distance from
satellitessatellites• Fourth satelliteFourth satellite
used for error used for error correctioncorrection
3. Global Positioning System3. Global Positioning System
Advantages:Advantages:• InexpensiveInexpensive• Low PowerLow Power• Gives absolute positionGives absolute position• Reliable over long periods Reliable over long periods
of timeof time Disadvantages:Disadvantages:
• Low accuracy for moving targetsLow accuracy for moving targets
4. Integration of GPS and INS4. Integration of GPS and INS Proposed DesignProposed Design Combines both systems into oneCombines both systems into one Takes advantage of each systemTakes advantage of each system
• Short term accuracy of INSShort term accuracy of INS• Long term reliability of GPSLong term reliability of GPS
GPS keeps INS errors in checkGPS keeps INS errors in check Use Kalman filter to improve Use Kalman filter to improve
accuracy of integrated systemaccuracy of integrated system
4. Integration of INS and GPS4. Integration of INS and GPS Advantages:Advantages:
• Most accurateMost accurate• Takes advantage of each systemTakes advantage of each system• Gives absolute positionGives absolute position
Disadvantages:Disadvantages:• More complexMore complex• Requires heavy computationRequires heavy computation• Requires more hardwareRequires more hardware
Conceptual DesignConceptual Design
Hardware ComponentsHardware ComponentsArdupilot Sensor Board - Six Degrees of Freedom
• Three axis accelerometer (x,y,z)• One axis gyroscope (roll)
Gyro Breakout Board - LPY5150AL Dual 1500°/s
• Dual axis gyroscope• Senses pitch and yaw
Hardware ComponentsHardware ComponentsVenus GPS with SMA Connector
•Up to 10Hz refresh rate•28mA operating current•Accuracy is <2.5m
•Passive Antenna•-5dB Gain
Quadrifilar V Omnidirectional Passive GPS Antenna