TEAM BRIGHTRIDERS

Failure Modes, Effects, and Criticality Analysis

“We put the SOUL in SOULAR racing”

Power Circuits

Power CircuitsFailure

No.Failure Mode Possible Causes Failure Effects Method of

DetectionCriti-cality

Remarks

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  

Power Circuits

Failure No.

Failure Mode Possible Causes Failure Effects Method of Detection

Criti-cality

Remarks

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  

SPI-to-UART and RS-232 circuits

SPI-to-UART and RS-232 circuits

FailureNo.

Failure Mode Possible Causes Failure Effects Method ofDetection

Criti-cality

Remarks

C1 No data received by chase car

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  

C2 Failure to enter diagnostic mode

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  

SPI-to-UART and RS-232 circuits

Failure No.

Failure Mode Possible Causes Failure Effects Method of Detection

Criti-cality

Remarks

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.

Communication tested during self-test

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.

Communication tested during self-test

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.

Communication tested during self-test

Low  

Analog Circuits

Analog Circuits

Failure No.

Failure Mode Possible Causes Failure Effects Method ofDetection

Criti-cality

Remarks

E1 Invalid or missing data from Accelerometers

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  

Microcontroller and CAN circuits

Microcontroller and CAN circuits

Failure No.

Failure Mode Possible Causes Failure Effects Method of Detection

Criti-cality

Remarks

F1 Microcontroller does not operate

Bypass capacitor failure, crystal circuit failure, microcontroller failure, power circuit failure, software bug

The Telemetry System is unoperational.

Observation High  

Microcontroller and CAN circuits

Failure No.

Failure Mode Possible Causes Failure Effects Method of Detection

Criti-cality

Remarks

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.

Communication 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.

Communication tested during self-test

Low