Self-Guided Wheelchair Design Review Presentation Student Members: Margaret Shangle Vee Shinatrakool...
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Transcript of Self-Guided Wheelchair Design Review Presentation Student Members: Margaret Shangle Vee Shinatrakool...
Self-Guided WheelchairSelf-Guided WheelchairDesign Review PresentationDesign Review Presentation
Student Members:Margaret ShangleVee Shinatrakool
Tara SpodenJohn Volkens
Brian Yauk
Faculty Advisor:Dr. Nicola Elia
Client:National Instruments
AgendaAgenda
Introduction Functional Requirements General Solution Detailed Design Summary
Presentation OverviewPresentation Overview
IntroductionIntroduction
Self-guided wheelchair• Capable of autonomously moving through
environment while avoiding any obstacles
• Selectable starting points/final destinations
• Based on motorized wheelchair
• Programmed with LabVIEW Embedded 8.2
• Sponsored by National Instruments
Project DescriptionProject Description
DefinitionsDefinitions
LabVIEW Embedded…. graphical programming language developed by National Instruments for implementation on OEM hardware
RF……………………….. (radio frequency) frequency that lies in the range within which radio waves may be transmitted, from about 10 kilohertz per second to about 300,000 megahertz.
Transponder…………… radio transmitter-receiver activated for transmission by reception of a predetermined signal. An RF reader/transmitter sends a signal via radio waves in order to detect transponders designed to read that reader’s particular frequency signal.
VI………………………… (virtual instrument) file containing subroutines or subfunctions created in LabVIEW
Project TerminologyProject Terminology
Functional RequirementsFunctional Requirements
Medical hospital setting Operation on a single floor level Free of stairs or similar large drop-offs Common hospital floor type
• Tile
• Hardwood
• Short carpet
Operating EnvironmentOperating Environment
Functional RequirementsFunctional Requirements
Primary User• Provides location information for the system input
• Shape recognition and basic literacy
• Medical staff or guardian
Secondary User• Passenger that will be transported
• Able to maintain a seated position within the confines of the chair dimensions
• Patient
Intended Users and UsesIntended Users and Uses
General SolutionGeneral SolutionEnd Product DescriptionEnd Product Description
FunctionalityRelative
ImportanceEvaluation
ScoreResultant
Score
LabVIEW Embedded controlled operation 35% 100% 35%
User-selectable starting and ending points 5% 95% 4.75%
Path calculation 10% 90% 9%
Obstacle detection 10% 90% 9%
Obstacle avoidance 5% 80% 4%
Location recognition 10% 50% 5%
Speed control (forward, reverse, stop) 15% 100% 15%
Turn control with 5% accuracy 10% 100% 10%
Total 100% 91.75%
General SolutionGeneral SolutionEnd Product DescriptionEnd Product Description
Inputs Processing Outputs
Starting position/final destination
Current location
Distance to obstacles
Magnetic orientation
Gyroscope orientation
Calculate path from start to end
Determine critical obstacles
Recalculate path from current
location
Left/right wheel control for intended
speed/turn
Left/right wheel control
Sensor stimuli
Input information (interfacing)
Location information (debugging)
General SolutionGeneral SolutionEnd Product DescriptionEnd Product Description
[0:7]
12Vreg
24V Battery
Joystick
Left/Right5.9V ± 0.9V
5.9V ± 0.9VForward/Reverse
[0:7]ADC
ADC
DB15
Motor Control Box
RS232
Controller
RFIDReader
Gyroscope
Compass
Sonar Array(x13)
Echo[0:12]
9Vreg5Vreg
Trigger[0:12]
LCDDisplay
USB
USB Keypad
ADC
ADC
General SolutionGeneral SolutionEnd Product DescriptionEnd Product Description
1 Controller2 LCD3 Keypad4 Compass5 Gyroscope6 Modified joystick7 Motor Control Box8 Batteries9 Sonar10 RFID Reader
12
3
4
59
7
8
10
6
Detailed DesignDetailed Design
Controller & Software - John
Sensors• Ranging Modules• Orientation
Motor Control Localization Power Management User Interface
OverviewOverview
Detailed DesignDetailed Design
VIA EPIA-EN12000EG Mini-ITX• 1.2GHz VIA C7 Fanless
Processor
• DDR2 533 SDRAM (up to 1 GB)
• Full range I/O including USB & Serial
Full PC capabilities• XP and LabVIEW Embedded
• Expandable
Multiple Peripheral I/O
Controller & SoftwareController & Software
Detailed DesignDetailed Design
Operating System• Windows XP Embedded
○ RFID Reader
Software• LabVIEW Embedded
○ All calculations, algorithms○ VIs for I/O to sensors
Program Flow…
Controller & SoftwareController & Software
Detailed DesignDetailed DesignController & SoftwareController & Software
Detailed DesignDetailed DesignController & SoftwareController & Software
Detailed DesignDetailed Design
Controller & Software Sensors - Brian
• Ranging Modules• Orientation
Motor Control Localization Power Management User Interface
OverviewOverview
Detailed DesignDetailed Design
• Uses:○ Navigation○ Obstacle detection
• Operation:○ Sends out a sonar pulse○ Calculates distance to
nearest object based on reflection time
○ 55° Angular Resolution
Ranging ModulesRanging Modules
Ultrasonic SRF04 Sonar Sensors
Detailed DesignDetailed Design
Mounting• Front:
○ Obstacle Detection○ Mapping
• Sides:○ Wall Tracking○ Hallway Detection
• Rear:○ Backing up
Ranging ModulesRanging Modules
Detailed DesignDetailed Design
• Uses:○ Find heading relative to
Earth’s magnetic field
• Operation:○ Pulse width modulated○ 1-37ms○ Accuracy: 3-4°
Orientation SensorsOrientation Sensors
Devantech R117 Magnetic Compass
Detailed DesignDetailed Design
• Uses:○ Gyroscope○ Measures rate of turning
• Operation:○ Detects up to 150°/s
Orientation SensorsOrientation Sensors
ADXRS150 Angular Rate Sensor
Detailed DesignDetailed Design
Controller & Software Sensors
• Ranging Modules• Orientation
Motor Control - Tara
Localization Power Management User Interface
OverviewOverview
Operation based on potentiometers• Forward / Reverse• Right / Left
5.9V ± 0.9V DC signal D/A converters
• Output from controller• 8-bits per speed, direction
○ Step Size = Span / 2n ≈ 7mV
Detailed DesignDetailed DesignMotor ControlMotor Control
Detailed DesignDetailed DesignMotor ControlMotor Control
Detailed DesignDetailed Design
Controller & Software Sensors
• Ranging Modules• Orientation
Motor Control Localization - Margaret
Power Management User Interface
OverviewOverview
Detailed DesignDetailed Design
• Uses:○ Identify current location
relative to onboard map○ Identify start/end point
• Operation:○ High Freq (13.56MHz)○ Sends RF signal to
transponders/tags○ Passive tags return ID
LocalizationLocalization
APSX RW-310 RFID Reader and Transponders
Detailed DesignDetailed Design
Mounting• Reader/Antenna
○ Bottom of chair○ 4” reading range
• Tags○ Floor○ Span critical intersections,
starting points/destinations
Connection○ RS232 -> USB
LocalizationLocalization
Detailed DesignDetailed Design
Controller & Software Sensors
• Ranging Modules• Orientation
Motor Control Localization Power Management User Interface
OverviewOverview
Power requirements:
Testing will rely on individual power supplies Not a priority for prototype design
Detailed DesignDetailed Design
• 24VDC○ Wheelchair
• 12VDC○ Mini-Itx Controller*
• 9VDC○ RFID Reader
• 5VDC○ Ultrasonic Sonar○ Gyroscope○ Compass
• USB (5VDC)○ Keypad○ LCD
Power ManagementPower Management
Detailed DesignDetailed Design
Individual systems:• Wheelchair, controller, RFID reader
5VDC system:
Power ManagementPower Management
Detailed DesignDetailed Design
Controller & Software Sensors
• Ranging Modules• Orientation
Motor Control Localization Power Management User Interface - Vee
OverviewOverview
Detailed DesignDetailed Design
• Uses:○ Gather inputs○ Display selected and
current locations○ Debugging
• Operation:○ 2x20 character display
• Connection:○ USB
User InterfaceUser Interface
Mini-box picoLCD
Detailed DesignDetailed Design
• Uses:○ Gather inputs○ Select starting location
and final destination○ Initiate travel○ Emergency stop
• Operation:○ 19-key
• Connection:○ USB
User InterfaceUser Interface
Targus USB Numeric Keypad
Other ConsiderationsOther Considerations
Economic/Environmental• RoHS compliant controller, wheelchair non-compliant (1991)
• Localization system comparatively inexpensive Social/Political/Ethical
• N/A Health/Safety
• System not designed for environments with large drop-offs
• Obstacle avoidance critical to passenger safety Manufacturability/Sustainability
• Prototype design – not designed for manufacture
• Proof of concept only
SummarySummary
LabVIEW Embedded controlled operation• Path calculation• Obstacle avoidance algorithm
User-selectable starting and ending points• Keypad, LCD
Obstacle detection• Sonar
Location recognition• RFID reader and tags
Motor speed control• D/A Converter
Turn control• Gyroscope, compass
QuestionsQuestions