Whitewater Kayak Slalom Race Timer

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Whitewater Kayak Slalom Race Timer
Engineers Kevin Lockwood Chris Munshaw Ashley
Penna John So
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Project Funded By

• Mike NeckarFounder, Necky Kayakswww.necky.com

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Background on Whitewater Kayaking

• Whitewater kayak slalom racing began shortly
  before World War II
• This Olympic sport involves racers paddling down
  a natural or man-made rive
• Kayakers must maneuver through hanging pairs of
  gates.
• Judges at shoreline determine correct maneuvering
  through gates.

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Background on Whitewater Kayaking
C1 (Canoe) on a man-made course
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Background on Whitewater Kayaking
K1 (Kayak) on a natural river course
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Kayak Rules

• The racer must proceed through green gates in the
  down-river direction
• Red gates in the up-river direction
• 2sec penalty for touch gates but going through
• 50sec penalty for touch and not gone through

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Present Situation

• Judge watching at each gate to make sure the
  kayaker goes though
• Judge determining if each gate has been touched
• Stop-watches used in training for timing
• Obvious problems Human error, biases, judges not
  omniscient

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Our Solution

• Create a automated system which tracks a
  kayakers progress through a race course and
  determines if gates are touched.
• Focus on creating a reliable and low cost
  product. Offset the cost of using humans to
  judge gates.
• Secondary goal is timing accuracy.

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Marketing

• Mr. Neckar- use for training by olympic
  athletes- introduced in races such as national
  team trials (Vedder River, Chilliwack)
• Scott Shipley, US national team member-
  promotion in the United States

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Timeline

• Overall, we are behind the proposed schedule
  by about two weeks.
• Our Proposed Timeline

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Delays are caused by

• Waiting for sensors, microcontrollers, and RF
  modules to arrive.
• Testing other design options.
• Errors and bugs
• Underestimated Integration Time
• Earlier than expected deadline

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Timeline
The Actual Timeline
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System Overview
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How to detect a Kayaker?

• Ultrasonic beam across the gates
• RF tag triangulation
• IR beam across the gates

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Ultrasonic Beam

• Advantages
• not affected by environment
• low noise
• low power consumption
• Disadvantages
• wide beam
• difficult to integrate multiple ultrasonic
  sensors due to coupled interference

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RF Tag

• Advantages
• Very hard to cheat the technology
• Low power
• Disadvantages
• Difficult technology to use
• Requires a high computational load to calculate
  location
• Can be expensive

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Optical Beam (Our Solution)

• Advantages
• Narrow beam
• Easy to implement
• Unaffected by environment
• Lower costs
• Disadvantages
• Consumes higher power the ultrasonic
• Sensitive to alignment

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IR LED vs. Laser

• Laser (Visible Spectrum) 650nm- coupled with a
  photodetector amplifier- very high signal
  strength at large distances (5m )- very narrow
  viewing angle- low power consumption (20mA)-
  class III and above can cause retinal damage

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IR LED vs. Laser

• IR LED 950nm- coupled with an NPN
  phototransistor - very low signal strength at
  distances over 2m (required amplification)- wide
  viewing angle (35) minimizing problem of gate
  flexibility- high power consumption (100mA)-
  cannot cause retinal damage

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IR LED Improving Signal Quality

• Ambient light shielding- used a non-reflective
  black paint to coat a drinking straw (this also
  formed a water-tight seal over the
  phototransistor)
• Modulation- modulated the IR emitter with a 2kHz
  square wave- demodulating at the receiving side
  would filter out noise cause by reflections of
  sunlight off water, etc

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IR LED Improving Signal Quality

• Ambient light shielding- used a non-reflective
  black paint to coat a drinking straw (this also
  formed a water-tight seal over the
  phototransistor)
• Modulation- modulated the IR emitter with a 2kHz
  square wave- demodulating at the receiving side
  would filter out noise cause by reflections of
  sunlight off water, etc

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IR LED Overall System

• Amplification -gt Filtering -gt Thresholding-
  Amplification boosts the output signal strength-
  Filtering creates a steady signal representing
  the amount of IR light detected- Thresholding
  creates a digital signal representing whether or
  not the line of sight is considered broken

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IR LED Modulation

• Decreased average current consumption from 180mA
  overall to 110mA overall.
• Waveform created using an astable 555 timer

Simulation on breadboard
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IR LED Demodulation

• Filtered using an LRC circuit, tuned to 2kHz

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IR LED Final Signal
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Accelerometer

• Used to detect any contact with the gate
• 3 axis, 5g output range
• Mounted 1 accelerometer per gate, in the lower
  region of the gate (added sensitivity)

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Accelerometer Signal Conditioning

• Low Pass Filter allows us to dull the signal
  and remove unwanted noise
• Comparator gives a digital signal representing
  whether or not the acceleration of the gate is
  beyond an acceptable level-gt this allows us to
  have the system ignore low acceleration
  conditions such as gates swaying in the wind

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Accelerometer Performance Tests

• Comparator Threshold 1.665V(red line in graph)

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Future Improvements on Signal Conditioning

• Have circuits printed on PCB
• Use only variable resistors reference voltages in
  comparators
• Improve demodulation circuit, possibly using an
  active filter

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Final Sensor Signals

• Two digital signals representing the clearance of
  a gate, and contact with a gate (both fully
  adjustable)
• However, current consumption is becoming high
  (approx. 180mA)
• This leads us to attempt Presence Detection

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Presence Detection

• Used to detect the presence of an approaching
  kayaker.
• Used to trigger the turn on high power consuming
  subsystem.
• Used Ultrasonic sensors
• Accuracy
• Immunity
• Ease

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Presence Detection

• The sensors have an analog output proportional to
  the distance of an object.
• Used thresholding to detect object presence
• Used timing circuit to filter noise.

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Presense Detection Future Upgrades

• Currently we do not have a way to detect which
  direction the kayaker came from.
• Gates are direction dependant according to
  whitewater kayak Rules.
• We will switch to IR presence detection, due to
  better immunity to environment.
• Will use one facing each direction in gate to
  determine direction of approach.

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Data Communication

• Requirements
• Reliable
• Long Range
• Low Power
• Fast Transmission

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Data Communication Solution

• ZigBee Xbee Module from Maxstream
• 30m range (upgrade 1mile)
• Current Consumption during Transmission 45mA
• UART Communication Format easy to integrate with
  our Micro Controller

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Data Communication Future Updates

• We can upgrade to Xbee Pro modules for an
  increased range.
• Requires more power.
• Allow software to communication back to gates.
• Remote reconfiguration
• Remote turn on/off

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MicroController Firmware

• Requirements
• Very little memory needed Simple program
• USART Register for RF Modules
• A/D Conversion capabilities
• At least 3 inputs (IR Sensors, Ultrasonic,
  Accelerometer)

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MicroController Firmware

• Main Jobs
• Get a development environment running
• Integration with ultrasonic to turn on power
  board
• Integration with IR sensors
• Integration with RF modules

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MicroController Firmware

• Multiple Development Environments
• 1) PICDEM
• 1st to work

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MicroController Firmware

• Good Features
• Easy viewing of ports
• Attached LEDs to eliminate the need to probe
• Multiple ways to power
• MPLab compatibility

• Problematic Features
• Had to replace 40-pin socket
• Initial running of programs
• Quantity

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MicroController Firmware

• Multiple Development Environments
• 2) OUMEX
• 2nd to work

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MicroController Firmware

• Good Features
• One LED to map outputs of interest to
• Programming capabilities using MPLab
• Less reliance on development board

• Problematic Features
• Building a cable from MPLab to ICSP
• Initial running of programs
• Quantity shipping time

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MicroController Firmware

• Multiple Development Environments
• 3) Prototype
• Last and finally!!!

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MicroController Firmware

• Good Features
• Cheap
• Space saving
• Easy connection to other circuits

• Problematic Features
• Must move to another development board to program
• Determining which components were necessary

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MicroController Firmware

• IR Flag gets set in an interrupt
• Accelerometer Flag gets set in an interrupt

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MicroController Firmware

• Ultrasonic Powering Sensor Circuit
• Creates an interrupt which sets a flag
• Main program deals with this
• Output will be high when ultrasonic is high
• IR sensors Circuit
• Creates an interrupt which sets a flag
• In main program, transmission showing the gate
  number and IR occurs

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MicroController Firmware

• Future Improvements
• Automatic Gate Addressing
• Sleep pins on the RF module
• Polling gates for possible battery voltage

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The Power

• IR sensors consume around 150mA.
• Portable/Inexpensive power source in a 9v battery
• Provide clean power at 3v and 5v for all
  subsystems.
• Supply should last for 8hrs of use

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Power Solution

• Isolated control directly from Micro Controller.
  
• Micro Controller uses the low power Ultra Sonic
  sensors to trigger IR sensor circuit.
• Circuit Board contains controlled outputs at 3v
  and 5v for high power, and continuous outputs of
  3v and 5v.

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Power Solution

• We want our portable power supplies to last 8
  hours of continuous usage
• System Power Consumption Before Power Control
  
• Total Power Required 1.21Ahr
• System Power Consumption After Power Control
• Total Power Required 0.511Ahr

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Power Solution

• Without a controlled power supply for 8hrs of
  continuous use requires 1.21Ahr
• With a controlled power supply for 8hrs
• Of continuous use requires 0.511Ahr
• Saves nearly 250 of our AmpHours required.
• Improves portable power supply options.

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Power Solution

• We use two Rayovac 9v Alkaline batteries in
  parallel for each gate
• Batteries spec at -30C to 55C
• Each Battery has approx. 0.5Ahr

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Graphical User Interface
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Graphical User Interface

• Purpose
• Allows user to set up a race quickly.
• Communicates with the RF module and collects data
  from gates.
• Displays data in table form.
• Automatically times the race and applies
  penalties.

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Graphical User Interface

• Functions
• Kayaker list management. Add and remove kayakers.
• Modify number of gates.
• File I/O
• Display data
• Names
• Race Time
• Penalties applied to each gate

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Graphical User Interface

• Program flow
• 1. User adds the names of kayakers in order.
• 2. User determines the number of gates.
• 3. User modifies the serial port settings.
• Step 1, 2 and 3 are interchangeable.
• 4. User presses Begin button to begin the race.
  Name list and gate number cannot be modified from
  this point onwards.

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Graphical User Interface

• Program flow (continued)
• 5. Program reads and displays data
  automatically.
• - Decodes gate messages sent through RF module
• - Applies 2 sec time penalty if gate touched.
• - Applies 50 sec time penalty if gate missed.
• 6. Calculate race time and add penalties to it.
• 7. Table may be exported in .txt format and
  uploaded to MS Excel.

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Graphical User Interface

• Problems encountered
• Exception handling
• Symbol error due to baud rate mismatch
• Repeated messages from gates
• Timing delay

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Graphical User Interface

• Future Improvements
• Time delay calculation
• Support multiple kayakers on the course
• Name list sorting
• Automatic available port detection

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Summary

• Created a automated system which tracks a
  kayakers progress through a race course and
  determines if gates are touched.
• Focus on creating a reliable and low cost
  product. Offset the cost of using humans to
  judge gates.
• Increased timing accuracy

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The End

• Questions?

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Appendix Signal Conditioning
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Appendix Modulation

• Emitter (Breadboard)

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Appendix Modulation

• Receiver, modulated (Breadboard)

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Appendix Demodulation

• RLC Bandpass Filter
• H(s)
• Using R1, C6.33uF, L1mH

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Appendix Demodulation
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Appendix Demodulation

• Receiver, de-modulated (Breadboard)

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Appendix UltraSonic Circuit

• Used a simple LM324 OpAmp with a threshold
  voltage. Threshold set to approx. 5.5ft.
• 555 Monostable Timing circuit holds detection
  high for 5sec. This filters the natural circuit
  noise from the ultrasonic sensor.

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Appendix Ultrasonic Circuit
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Appendix Power Requirments

• Before Power Control
• Continuous Power Consumption
• 110mA (IR circuit) 15mA (Ultrasonic) 25mA
  (Micro) 150mA
• RF Consumption
• (150 trans. approx._at_ 0.5 sec/trans) 0.9mA
• Total Power Required 1.21Ahr
• After Power Control
• Continuous Consumption
• 15mA (Ultrasonic) 25mA (Micro) 40mA
• IR Consumption
• 110mA (150 passes. approx._at_ 5 sec/pass) 23mA
• RF Consumption
• 45mA (150 trans. approx._at_ 0.5 sec/trans) 0.9mA
• Total Power Required 0.511Ahr

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Appendix Power Circuit
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Appendix Power Circuit Lag(4ms)
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Appendix Transmission
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Appendix Transmission
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Appendix Transmission Time