Transcript Reliability and Safety Presentation

Steve Andre
Eric Glover
Shaun Greene
Russell Willmot
An ability to:
1.
2.
3.
4.
5.
display a pattern with rotating LEDs
control the direction in which the pattern is being projected
track the angle of arrival of an RF beacon
update a projected image while the machine is in operation
accept user-generated input to change display
•Potential Injury to User (HIGH)
 = 10-9 failures/106 hours
•Damage to POV Machine or Parts (MEDIUM)
 < 10-7 failures/106 hours
•POV Machine functional problems (LOW)
 < 10-5 failures/106 hours
• PIC24FJ64GA004 Microcontroller
•Receives data from transceiver
•Sends data and latching signals to LED Post
•TI 5V Switching Regulator (TPS54357PWP)
•Rotating board- Regulates voltage from slip rings
•Stationary board – Regulates voltage from bridge rectifier
•TI 3.3V LDO Regulator (TPS77833D)
•Utilized on rotating and stationary boards
Failure
No.
Failure Mode
Possible Causes
Failure Effects
1
None or only
partial
illumination of
LEDs
2
POV image does
not update
3
POV Image
Pulse Accumulator or Microcontroller does
randomly wanders IR Sensor not working not properly ready
properly
zero-position so POV
image randomly
wanders
PIC Microcontroller
SPI module not
working, does not
properly send data to
LED Drivers (data,
latch, chip enable) ,
data from transceiver
not read properly,
oscillator doesn’t work
SPI module not
working
Method of
Detection
Criticality
None or only partial
illumination of LEDs
None or only
partial
illumination of
LEDs
LOW
Projected image does
not update, no
communication with
transceiver
POV image does
not update when
user selects new
image, or user RF
Beacon moves
LOW
Zero-positioning
“wanders”
LOW
Remarks
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
MEDIUM
1
Output Voltage =
0V
Switching regulator is Nothing turns on
fried , input voltage =
0.
Nothing turns
on
2
Output Voltage
consistently not 5
Volts
Chips overheat,
catch on fire,
etc.
3
Noisy Output
Voltage
Improper read on
feedback pin
(VSENSE), bypass
caps shorted,
overloading,
excessive heat
Excessively noisy
input voltages, noisy
feedback voltages,
high inductive or
capacitive transient
loading
Chips are fried,
unpredictable
Glitches in digital Random
logic,
behavior from
Unpredictable, 3.3 POV Machine
Volt regulator
shutdown
HIGH
MEDIUM
Remarks
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
MEDIUM
1
Output Voltage =
0V
Switching regulator is Nothing turns on
fried , input voltage =
0.
Nothing turns
on
2
Output Voltage
consistently not
3.3 Volts
Bypass caps shorted,
overloading ,
overheating
Chips are fried,
unpredictable
Chips overheat,
catch on fire,
etc.
3
Noisy Output
Voltage
Excessively noisy
input voltages, noisy
feedback voltages,
high inductive or
capacitive transient
loading
Unpredictable,
Random
Glitches in digital behavior from
logic
POV Machine
HIGH
MEDIUM
Remarks