Transcript Failure Modes Presentation

TEAM BRIGHTRIDERS
“We put the SOUL in SOULAR racing”
Failure Modes, Effects, and
Criticality Analysis
Power Circuits
Power Circuits
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
A1
VDD5v = 0v
Switching regulator circuit
component failures,
internal or external
shorts, under voltage or
disconnect on voltage
supply line
Telemetry System cannot operate.
Observation
High
A2
0v < VDD5v < 4.2v
Switching regulator circuit
component failures,
internal or external
shorts, under voltage
on supply line
Microcontroller has an under-spec
voltage supply for the
operating frequency. The
Telemetry System may not
operate.
Observation
High
A3
4.2v < VDD5v < 4.5v
Switching regulator circuit
component failures,
internal or external
shorts, under voltage
on supply line
RS232 Tranciever and CAN
Tranciever under voltage
spec and may not operate,
Accelerometer out of
calibrated range.
Observation
High
A4
VDD5v > 5.5v
Switching regulator circuit
component failures,
internal or external
shorts, over-voltage on
supply line
All 5 volt components are over
voltage spec, possible
hardware damage, excess
heating or failure to operate.
Observation
High
Remarks
Power Circuits
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
B1
VDD3.3v = 0v
Linear regulator failure,
internal or external
shorts, under voltage or
disconnect on VDD5v
SPI-to-UART chips cannot
operate, Telemetry system
will be unable to
communicate with the
Battery, Motor, and GPS.
Observation
High
B2
0v < VDD3.3v < 3.0v
Linear regulator failure,
internal or external
shorts, under voltage
on VDD5v
SPI-to-UART chips are under
voltage spec, Telemetry
system may be unable to
communicate with the
Battery, Motor, and GPS.
Observation
High
B3
VDD3.3v > 3.6v
Linear regulator failure,
internal or external
shorts, over-voltage on
VDD5v
SPI-to-UART chips are over
voltage, Telemetry system
may be unable to
communicate with the
Battery, Motor, and GPS, as
well as possible hardware
damage and excess heating.
Observation
High
Remarks
SPI-to-UART and RS-232 circuits
SPI-to-UART and RS-232 circuits
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
C1
No data received by
chase car
C2
Failure to enter
diagnostic
mode
Criticality
Packet modem out of range
or unoperational,
UART module of
microcontroller unable
to transmit, RS232
transceiver failure,
software bug
The Telemetry System is
unoperational.
Observation
High
Packet modem out of range
or unoperational,
UART module of
microcontroller unable
to receive, RS232
transceiver failure,
software bug
Diagnostic mode is unavailable,
but the major part of the
Telemetry System is
functional.
Observation
Low
Remarks
SPI-to-UART and RS-232 circuits
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
D1
Invalid or missing
data from Battery
SPI-to-UART chip failure,
SPI-to-UART chip select stuck
high or low, crystal circuit
failure, RS232 transceiver
failure, SPI module of
microcontroller failure, cable
disconnect, software bug
Driver unable to read and
manage battery levels. Possible
battery over-charge.
Communicati
on tested
during selftest
High
D2
Invalid or missing
data from Motor
SPI-to-UART chip failure,
SPI-to-UART chip select stuck
high or low, crystal circuit
failure, RS232 transceiver
failure, SPI module of
microcontroller failure, cable
disconnect, software bug
Unable to log motor data for
performance analysis.
Communicati
on tested
during selftest
Low
D3
Invalid or missing
data from GPS
SPI-to-UART chip failure,
SPI-to-UART chip select stuck
high or low, crystal circuit
failure, RS232 transceiver
failure, SPI module of
microcontroller failure, cable
disconnect, software bug
Unable to log GPS data for
aerodynamic analysis.
Communicati
on tested
during selftest
Low
Remarks
Analog Circuits
Analog Circuits
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
E1
Invalid or missing
data from
Acceleromete
rs
Accelerometer failure, A/D
module of
microcontroller failure,
improper alignment of
telemetry system,
software bug.
Unable to log acceleration data for
aerodynamic analysis.
Operation and
validity
tested
during
self-test
Low
E2
Invalid or missing
data from
Temperature
Sensor
Temperature sensor failure,
A/D module of
microcontroller failure,
software bug.
Unable to log internal car
temperature for analysis.
Operation and
validity
tested
during
self-test
Low
Remarks
Microcontroller and CAN circuits
Microcontroller and CAN circuits
Failure
No.
F1
Failure Mode
Microcontroller
does not
operate
Possible Causes
Bypass capacitor failure,
crystal circuit failure,
microcontroller failure,
power circuit failure,
software bug
Failure Effects
Method of
Detection
The Telemetry System is
unoperational.
Observation
Criticality
High
Remarks
Microcontroller and CAN circuits
Failure
No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Criticality
G1
CAN module
cannot
transmit
CAN transceiver failure,
CAN module failure
on microcontroller,
power circuit failure,
cable disconnect,
software bug.
Driver interface unable to update.
Driver unable to read and
manage battery levels.
Possible battery over-charge.
Communicati
on
tested
during
self-test
High
G2
CAN module
cannot
receive
CAN transceiver failure,
CAN module failure
on microcontroller,
power circuit failure,
cable disconnect,
software bug.
Unable to log maximum power
point tracker data for
performance analysis.
Communicati
on
tested
during
self-test
Low
Remarks