Transcript Team10TCSP0221

Technical
Communication Skills
Practicum (TCSP)
Presented by
Nuhairi & Azad
Team 10: “Hazard Rover”
2/21/2007
HAZARD ROVER

At-A-Glance:
– Web-based Wi-Fi control interface
– Wireless webcam streams video to website
– Capabilities:
 Movement
 Light sensor/LED
 Robotic Arm
– Model, designed for use in hazardous areas
HAZARD ROVER
SCHEMATIC

six different subsystems: Power Supply
(P), Sensors (S), Motor Control (D),
Microcontroller (M), Wi-Fi Interface (F),
and Webcam (W)
OVERALL SCHMEMATIC
ARM MOTOR
POWER
CAMERA SERVO
STEERING MOTOR
STEERING SENSOR
LEVELS OF CRITICALITY
– Negligible
 Rover can continue to function close to normally
– Potentially Hazardous
 Rover may be able to function partially depending
on severity of failure
– Hazardous
 Failure will result in the rover’s inability to
complete its task
– Dangerous
 Failure could possibly cause the rover to become a
destructive force.
FMECA Analysis: Power Supply
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of Detection
Criticality
P1
Battery Voltage
too low
Chemical defect in
battery, overuse, needs
recharging
Possible inoperation of
other components
Dim LED, voltmeter, lack
of functionality of some
components, battery life
readings on
microcontroller incorrect
Potentially
Hazardous
P2
Voltage
Regulator output
too high
Input too high, short
within regulator
Damage to any
components supplied by
regulator, overheating
Regulator or other
components heating up,
not functioning properly
Hazardous
P3
Voltage
Regulator output
too low
Faulty/shorted bypass
capacitor (C8), Input
too low, short within
regulator
Possible inoperation of
components supplied by
regulator
Dim LED, voltmeter, lack
of functionality of some
components
Potentially
Hazardous
FMECA Analysis: Sensors
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of Detection
Criticality
S1
Light sensor
readings
inaccurate
Obstruction of sensor,
parts of sensor faulty
Inaccurate readings,
improper LED function
LED does not light up
in the dark, or lights up
in the light
Negligible
S2
LED always on
Improper readings, short
in connections
More power
consumption, possible
damage to
microcontroller
LED is always on
Negligible
S3
LED always off
LED burned out, short in
connections
Possible lack of night
vision, possible damage
to microcontroller
LED is always off
Negligible
FMECA Analysis: Motor Control
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of Detection
Criticality
D1
Pan/Tilt servos
not moving
properly
Damage to motor, input
signal is too fast for AND
gate tolerance (U17A,B)
Inablility to move
camera, possible
damage to AND gates
Camera movement not
operational, motors
heating up
Hazardous
D2
Pan/Tilt servos
not
moving/stuck
Faulty AND gate, short in
motor
Inability to move
camera, possible
damage to AND gates
Camera movement not
operational, motors
heating up
Hazardous
D3
Arm/steering
motors always
off
Faulty bypass capacitor,
faulty DC Motor Driver,
short in motor
Damage to driver chip,
motors, or
microcontroller
Inability to move
robotic arm or steer,
motors getting hot
Hazardous
D4
Arm/steering
motors always
on
Short in Driver chip,
connections from
microcontroller
Damage to driver chip,
motors, or
microcontroller
Steering always in the
same direction, robotic
arm stuck in one
position
Hazardous
D5
Drive motor
always off
Short in H-Bridge chip,
connections to
microcontroller
Damage to driver chip,
motor, or
microcontroller
Inability to move
Hazardous
D6
Drive motor
always on
Short in H-Bridge chip,
connections to
microcontroller
Damage to driver chip,
motor, or
microcontroller
Inability to stop or
control rover
Dangerous
FMECA Analysis: Microcontroller
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of Detection
Criticality
M1
Output not
correct
Possible corruption of
assembly code in memory,
shorts within or near ports
Incorrect operation of
components connected
to microcontroller
Incorrect operation of
various components
Potentially
Hazardous
M2
Output not
present
Microcontroller not
receiving power, damaged
microcontroller
Inoperation of all
components
Inoperation of all
components
Hazardous
FMECA Analysis: Wi-Fi Interface
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of Detection
Criticality
F1
Data received
from Wi-Fi link
incorrect
Possible short in
connection, signal
interference, faulty
wireless bridge
Damage to
microcontroller,
wireless bridge
Operation of
components not to
user’s specification
Potentially
Hazardous
F2
No data
received from
Wi-Fi link
Broken connection,
damage to wireless bridge
Microcontroller
software detection
should stop all rover
movement
All movement on rover
stops
Hazardous
FMECA Analysis: Webcam
Failure
No.
Failure
Mode
Possible Causes
Failure Effects
Method of Detection
Criticality
W1
Webcam
video data
corrupted
Possible short in
connection, signal
interference, faulty
wireless webcam
link, weak signal
Possible damage to
webcam/receiver
Video data not
present or
distorted/corrupted
Potentially
Hazardous
W2
Webcam
video data
not present
Broken
connection,
damage to
webcam/receiver
No video feed to
user, possible
damage to
webcam/receiver
No video feed to user
Hazardous
Remarks
In this case, the user
should stop moving all
motors to prevent any
further dangerous
situations