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Safety and Reliability Safety and Reliability Analysis Analysis

Team KANG Team KANG Group 1 Group 1

MC9S12XD Microcontroller Reliability Analysis λp = (C1πT + C2πE)πQπL (Microcircuit Model)

Parameter Value Justification / Assumptions

C1 0.280 16 Bit Microprocessor, MOS ([1], Section 5.1) C2 0.077 144 Pin, Nonhermetic SMT Packaging, Value determined by interpolation ([1], Section 5.9) πT 3.1 Digital MOS Device Assumptions: TJ=125°C. ([1], Section 5.8) πE 2.0 Ground Fixed Environment ([1], Section 5.10) πQ 10.0 Commercial Component ([1], Section 5.10) πL 1.0 Years in Production >= 2 ([1], Section 5.10)

λp 10.22 Failures/Million hours MTTF 9.78E4 hours ~ 11.2 years

GAL26CV12 PLD Reliability Analysis λp = (C1πT + C2πE)πQπL (Microcircuit Model)

Parameter Value Justification / Assumptions

C1 .0017 PLA, 1000 Gates, MOS ([1], Section 5.1) C2 .013 28 Pin, Nonhermetic DIP Packaging ([1], Section 5.9) πT 3.1 Digital MOS Device Assumptions: TJ=125°C. ([1], Section 5.8) πE 2.0 Ground Fixed Environment ([1], Section 5.10) πQ 10.0 Commercial Component ([1], Section 5.10) πL 1.0 Years in Production >= 2 ([1], Section 5.10)

λp .3127 Failures/ Million hours MTTF 3.20E6 hours ~ 365.1 years

TIP122 (Darlington NPN Expitaxial Transistor) Reliability Analysis λp = λbπTπAπQπE (Transistor Model)

Parameter Value Justification / Assumptions

λb .012 NPN, Si MOSFET ([1], Section 6.4) πT 5.1 Assumptions: TJ=125°C. ([1], Section 6.4) πA 4.0 Power MOSFET, Assumption: PR = 6 V * 6 A = 30 W ([1], Section 6.4) πQ 8.0 Assumption: Plastic (worst case scenario) ([1], Section 6.4) πE 6.0 Ground Fixed Environment ([1], Section 6.4)

λp 11.75 Failures/Million hours MTTF 8.51E4 hours ~ 9.7 years

MAX3232 Level Translator Reliability Analysis λp = (C1πT + C2πE)πQπL (Microcircuit Model)

Parameter Value Justification / Assumptions

C1 0.040 Linear MOS, 399 Transistor count ([1], Section 5.1) C2 0.072 16 Pin, Nonhermetic SMT Packaging ([1], Section 5.9) πT 0.98 Linear MOS Device Assumptions: TJ= 85°C. ([1], Section 5.8) πE 2.0 Ground Fixed Environment ([1], Section 5.10) πQ 10.0 Commercial Component ([1], Section 5.10) πL 1.0 Years in Production >= 2 ([1], Section 5.10)

λp 1.83 Failures/Million hours MTTF 5.46E5 hours ~ 62.3 years

• A. Microcontroller
• B. Sensors
• C. Fire Control
• D. Motor Control/ Motor Driver
• E. User Interface
• F. Video
• G. RAM
• H. Power

Safety Analysis – FUNCTIONAL BLOCKS

A C E B F H G D

Levels of Criticality Levels of Criticality

Criticality Failure Effect Maximum Probability Low Device stops functioning or is damaged, but reparable λp ≥ 10-6 High Irreparable damage to the device and harm to user λp ≤ 10-9

Failure Failure No. No. Failure Failure Mode Mode Possible Possible Causes Causes Failure Failure Effects Effects Method Method

• f
• f

Detection Detection Criticality Criticality Remark Remark

A1 A1 MCU Failure MCU Failure Short of Short of bypass caps bypass caps Failure of Failure of MCU MCU

Unpredictability Unpredictability

• f MCU
• f MCU

Dead MCU Dead MCU Human Damage Human Damage

Observation Observation High High Can be Can be lethal to lethal to humans humans B1 B1 Failure of Failure of friendly friendly Detection Detection Failure of IR Failure of IR Transmitter Transmitter

• r Receiver
• r Receiver

Gun Gun functions as functions as if everything if everything is enemy is enemy Observation Observation High High Friendlies Friendlies get shot get shot

• nce motion
• nce motion

sensor is sensor is tripped in tripped in auto auto-

• mode

mode B2 B2 Failure of Failure of Enemy Enemy Detection Detection Failure of Failure of Motion Motion Sensors Sensors Enemy not Enemy not detected, detected, user at user at harms way harms way Observation Observation High High C1 C1

Gun shoots Gun shoots unpredictably unpredictably

TIP122 TIP122 failure failure MCU failure MCU failure User harm User harm Observation Observation High High Friendly can Friendly can get shot get shot even if IR even if IR remote remote works works D2 D2

Unpredictable Unpredictable motion of gun motion of gun

Failure of Failure of GAL GAL Gun can Gun can move to move to friendly and friendly and shoot shoot Observation Observation High High

Failure Failure No. No. Failure Mode Failure Mode Possible Possible Causes Causes Failure Effects Failure Effects Method of Method of Detection Detection Criticality Criticality Remark Remark D4 D4 Unpredictable Unpredictable motion of motion of camera camera Failure of Failure of driver driver Failure of Failure of GAL GAL Video Video Alg Alg run where run where the camera moves the camera moves Enemy Evades Enemy Evades Observation Observation High High E1 E1 User Interface User Interface communication communication failure failure MAX3232 MAX3232 failure failure Shorted Shorted bypass bypass Manual override Manual override failure failure Observation Observation High High H3 H3 AC line failure AC line failure Bad power Bad power splitting splitting Shorted PCB Shorted PCB Observation Observation High High Device will be Device will be irreparable irreparable

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