Team 3 ATV Daniel Barrett Sebastian Hening Sandunmalee Abeyratne Anthony Myers

High Criticality A failure that has the potential to injure the user or others Medium Criticality A failure that can permanently damage components of the device Low Criticality A failure that would change the functionality of the device or affect its performance

Devices prone to fail Freescale 9S12C32 microcontrollers Murata OKR-T 5V switching regulator BQ2002 Batter charging IC L298 dual H-Bridge

μController 1 Failure No.Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRe ma rks A1PWM signal failure Failure of HC9S12C32 pins PT0-PT3. The camera servos will not work.ObservationMedium A2SCI failureFailure of the HC9S12C32 pins TX and RX. Unable to communicate to atom board. ObservationMedium A3Failure of range sensors Failure of the HC9S12C32 ATD pins AN3- AN5 Unable detect obstacles. Can result in injury of others. ObservationHigh A4Failure to Reset or run Failure of R9 or Pushbutton The microcontroller is unable to reset or is being constantly reset ObservationMedium A5Failure of SPIFailure of HC9S12C32 SPI pins PM2-PM5 Unable to read the accelerometer data. Will make the calculation of the current location less accurate ObservationLow A6Failure of TimerFailure of HC9S12C32 timer pins PT6- PT7 Unable to determine the speed and direction of the robot ObservationMedium

μController 2 Failure No.Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks B1Failure of Motor logic signals Failure of the HC9S12C32 AN0-AN3 pins Unable to control the movement of the robot. ObservationHigh B2SCI failureFailure of the HC9S12C32 pins TX and RX. Unable to communicate to atom board. ObservationMedium B3SPI FailureFailure of the HC9S12C32 pins PM2-PM5 or failure of Compass Unable to determine the direction of movement of the robot ObservationLow B4Failure to ResetFailure of R9 or Pushbutton The microcontroller is unable to reset or is being constantly reset ObservationMedium B5Failure of PWM signal Failure of the HC9S12C32 pins PT0-PT1 The motors are not able to stop ObservationHigh

μController Parameter nameDescriptionValueComments regarding choice of parameter value, especially if you had to make assumptions. C1Die complexity.14CMOS, 8-Bit πTπT Temperature coeff..71Assume linear temp of 50 C C2Package Failure Rate Pins, Nonhermetic πEπE Environmental Factor4.0Ground Mobile πQπQ Quality Factor10Commercially Manufactured component πLπL Learning Factor1More than 2 years in production λPλP Part Failure Rate1.594Failures /10^6 hours MTTF Hours = 71.5 Years

Murata OKR-T 5V Regulator Failure No.Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks D1Vout < 5VR15 fails and causes an open circuit The servos, sensors and microcontrollers do not function ObservationMedium D2Vout >5VR15 fails and shorts The sensors and microcontroller might be damaged ObservationMedium D3Vout 5V Failure of OKR- T switching regulator UnpredictableObservationMedium

Murata OKR-T Parameter nameDescriptionValueComments regarding choice of parameter value, especially if you had to make assumptions. C1Die complexity.011 to 100 Linear MOS gates πTπT Temperature coeff..71Assume linear temp 50 C C2Package Failure Rate.0025 Pins, Nonhermetic πEπE Environmental Factor4.0Ground Mobile πQπQ Quality Factor10Commercially Manufactured component πLπL Learning Factor1More than 2 years in production λPλP Part Failure Rate.207Failures /10^6 hours MTTF 551 Years

H-Bridge Failure No.Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks E1Unable to control motors One of the Resistors R21- R26 fails or one of the six 4n33 optical isolators fails Motor behave randomly and cannot be controlled ObservationHigh E2H-bridge failureFailure of the L298 H-bridge Unpredictable, motors cannot be controlled and robot might run into someone resulting in injury ObservationHigh

L298 dual H-Bridge Parameter nameDescriptionValueComments regarding choice of parameter value, especially if you had to make assumptions. C1Die complexity.011 to 100 Linear MOS gates πTπT Temperature coeff.2.8Linear MOS at 70C C2Package Failure Rate Pins, Nonhermetic πEπE Environmental Factor4.0Ground Mobile πQπQ Quality Factor10Commercially Manufactured component πLπL Learning Factor1More than 2 years in production λPλP Part Failure Rate.548Failures /10^6 hours MTTF Years

Battery Charging Circuit Failure No.Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks F1Current source failure LM-317 failureThe battery does not charge ObservationLow F2Failure of charging IC Failure of BQ2002/F chip Failure to detect when battery is charged which can lead to destruction of battery. Batter can also explode. ObservationHigh F3Failure of Q1Failure of the Q1 transistor Unpredictable. Unable to start charging or stop charging the battery. Battery can explode or ignite. ObservationHigh F4Failure of Q2Transistor Q2 fails This is in place only in case other components fail. Its failure might in the worst case make the battery unable to be charged. ObservationLow F5Current soure > 1 A Resistors R5 or R6 fail. LM317 current source breaks ObservationLow F6Current soure <1A Resistor R5 or R6 failure The battery doesn’t fully charge ObservationLow

BQ2002 Parameter nameDescriptionValueComments regarding choice of parameter value, especially if you had to make assumptions. C1Die complexity to 1000 Linear MOS gates πTπT Temperature coeff..71Assume linear temp of 50 C C2Package Failure Rate Pins, Nonhermetic πEπE Environmental Factor4.0Ground Mobile πQπQ Quality Factor10Commercially Manufactured component πLπL Learning Factor1More than 2 years in production λPλP Part Failure Rate.278Failures /10^6 hours MTTF 410 Years

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