reliability and safety analysis
DESCRIPTION
Reliability and Safety Analysis. (Left to Right) Matt Finn Brian Crone Samuel Oshin Yonatan Feleke. Project Overview. Future Cash Register The future cash register is a point of sale box designed to make wireless transactions through the use of Near Field Communications protocol. - PowerPoint PPT PresentationTRANSCRIPT
Reliability and Safety Analysis
(Left to Right)
Matt FinnBrian Crone
Samuel OshinYonatan Feleke
Project Overview Future Cash Register
• The future cash register is a point of sale box designed to make wireless transactions through the use of Near Field Communications protocol.
• It will accept payments and send receipts through NFC. It will also aide the cashier with orders through voice recognition.
Project-Specific Success Criteria Ability to customize the inventory via the user
interface (Atom)
Ability to communicate with an NFC device (dSPIC30)
Ability to interface with an IR sensor to detect the presence of a user (dSPIC30)
Ability to display prompts to user through LCD (dSPIC30)
Ability to aid cashier by highlighting menu choices while placing order with voice recognition (Atom)
Block Diagram
Definition of Criticality Levels
High• System irreparable• Potential for user injury
Medium• System irreparable• Little/no potential for user injury
Low• System still functional• User inconvenience
Components Under Consideration Voltage Regulator
RS232 Level Translator
Microcontroller
NFC Controller
Voltage Regulator - λP C1 = .02 (101 to 300 transistors) πT = 16.0 (<100˚C) C2 = 0.0012 (3 pins) π E = 2.0 (Ground fixed
environment) π L = 1.0 ( > 2 years) π Q = 10.0 (Commercial Grade)
λP = (C1 x πT + C2 x πE ) x π L x πQ
= 3.224 failures/106 hours
FMECAFailure No. Failure
ModePossible Causes
Failure Effects
Method of Detection
Criticality
Voltage RegulatorA1 Output = 0V Failure of
regulator or passive components, external short
Unable to operate
Observation, package heating up, no response from micro to GUI
Medium
A2 Output > 5V Regulator Failure
Component destruction, Overheating
Observation High
A3 Output out of tolerance
Regulator, Passive Component Failure
Operating voltages wrong, unpredictable
Observation, voltage probes
Medium
RS232 Translator - λP C1 = .02 (101 to 300 transistors) πT = 7.0 (<85˚C) C2 = 0.0072 (16 pins) π E = 2.0 (Ground fixed
environment) π L = 1.0 ( > 2 years) π Q = 10.0 (Commercial Grade)
λP = (C1 x πT + C2 x πE ) x π L x πQ
= 1.544 failures/106 hours
FMECAFailure No. Failure
ModePossible Causes
Failure Effects
Method of Detection
Criticality
RS232 TranslatorB1 Output = 0V Failure of
translator or passive components, external short
Atom and Micro unable to communicate
Observation, No messages from micro
Medium
B2 Output not translated
MAX3232 Failure
Atom and Micro unable to communicate, high voltage to Micro
Observation, Voltage probes, no messages from micro
Medium
Microcontroller - λP C1 = .28 (16-bit, MOS) πT = 3.1 (125˚C) C2 = 0.032 (64 pins) π E = 2.0 (Ground fixed
environment) π L = 1.0 ( > 2 years) π Q = 10.0 (Commercial Grade)
λP = (C1 x πT + C2 x πE ) x π L x πQ
= 9.32 failures/106 hours
FMECAFailure No. Failure
ModePossible Causes
Failure Effects
Method of Detection
Criticality
MicrocontrollerD1 Output
continuously 0
Software, Passive Components, Short
System not functional, blocks not communicating
Observation, Software debugging, probes
Medium
D2 Output continuously 1
Software, Passive components
Improper communication between blocks, no real functionality
Observation, check LEDs and messages on GUI
Medium
NFC Controller - λP C1 = .14 (8-bit, MOS) πT = .96 (85˚C) C2 = 0.019 (40 pins) π E = 2.0 (Ground fixed
environment) π L = 1.0 ( > 2 years) π Q = 10.0 (Commercial Grade)
λP = (C1 x πT + C2 x πE ) x π L x πQ
= 0.5144 failures/106 hours
FMECAFailure No. Failure
ModePossible Causes
Failure Effects
Method of Detection
Criticality
NFC ControllerD1 Output
continuously 0
Oscillator Failure, Passive Components, Short
NFC data will not be sent/received. Payment not possible
Observation, correct payment information not received
Low
D2 Incorrect operating frequency
Oscillator failure
Improper data communication, potential for losing data, incorrect payment information
Observation, Verify payment information with receipt
Low
Questions