Safety and Reliability Safety and Reliability Analysis Analysis - PowerPoint PPT Presentation

Safety and Reliability Safety and Reliability Analysis Analysis Team KANG Team KANG Group 1 Group 1

MC9S12XD Microcontroller Reliability Analysis λ p = (C 1 π T + C 2 π E ) π Q π L (Microcircuit Model) Parameter Value Justification / Assumptions C 1 0.280 16 Bit Microprocessor, MOS ([1], Section 5.1) 144 Pin, Nonhermetic SMT Packaging, Value determined by C 2 0.077 interpolation ([1], Section 5.9) 3.1 Digital MOS Device π T Assumptions: T J =125 ° C. ([1], Section 5.8) 2.0 Ground Fixed Environment ([1], Section 5.10) π E 10.0 Commercial Component ([1], Section 5.10) π Q 1.0 Years in Production >= 2 ([1], Section 5.10) π L λ p 10.22 Failures/Million hours MTTF 9.78E4 hours ~ 11.2 years

GAL26CV12 PLD Reliability Analysis λ p = (C 1 π T + C 2 π E ) π Q π L (Microcircuit Model) Parameter Value Justification / Assumptions C 1 .0017 PLA, 1000 Gates, MOS ([1], Section 5.1) C 2 .013 28 Pin, Nonhermetic DIP Packaging ([1], Section 5.9) 3.1 Digital MOS Device π T Assumptions: T J =125 ° C. ([1], Section 5.8) 2.0 Ground Fixed Environment ([1], Section 5.10) π E 10.0 Commercial Component ([1], Section 5.10) π Q 1.0 Years in Production >= 2 ([1], Section 5.10) π L λ p .3127 Failures/ Million hours MTTF 3.20E6 hours ~ 365.1 years

TIP122 (Darlington NPN Expitaxial Transistor) Reliability Analysis λ p = λ b π T π A π Q π E (Transistor Model) Parameter Value Justification / Assumptions λ b .012 NPN, Si MOSFET ([1], Section 6.4) Assumptions: T J =125 ° C. ([1], Section 6.4) 5.1 π T 4.0 Power MOSFET, π A Assumption: P R = 6 V * 6 A = 30 W ([1], Section 6.4) 8.0 Assumption: Plastic (worst case scenario) ([1], Section 6.4) π Q 6.0 Ground Fixed Environment ([1], Section 6.4) π E λ p 11.75 Failures/Million hours MTTF 8.51E4 hours ~ 9.7 years

MAX3232 Level Translator Reliability Analysis λ p = (C 1 π T + C 2 π E ) π Q π L (Microcircuit Model) Parameter Value Justification / Assumptions C 1 0.040 Linear MOS, 399 Transistor count ([1], Section 5.1) C 2 0.072 16 Pin, Nonhermetic SMT Packaging ([1], Section 5.9) 0.98 Linear MOS Device π T Assumptions: T J = 85 ° C. ([1], Section 5.8) 2.0 Ground Fixed Environment ([1], Section 5.10) π E 10.0 Commercial Component ([1], Section 5.10) π Q 1.0 Years in Production >= 2 ([1], Section 5.10) π L λ p 1.83 Failures/Million hours MTTF 5.46E5 hours ~ 62.3 years

Safety Analysis – FUNCTIONAL BLOCKS A. Microcontroller B. Sensors C. Fire Control D. Motor Control/ Motor Driver E. User Interface F. Video G. RAM H. Power

H C B D A F G E

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

Failure Failure Possible Failure Method Criticality Remark Failure Failure Possible Failure Method Criticality Remark No. Mode Causes Effects of No. Mode Causes Effects of Detection Detection Unpredictability A1 A1 MCU Failure MCU Failure Short of Short of Unpredictability Observation Observation High High Can be Can be of MCU of MCU bypass caps lethal to bypass caps lethal to Dead MCU Dead MCU humans humans Failure of Failure of Human Damage Human Damage MCU MCU B1 Failure of Failure of IR Gun Observation High Friendlies B1 Failure of Failure of IR Gun Observation High Friendlies friendly friendly Transmitter Transmitter functions as functions as get shot get shot Detection or Receiver if everything once motion Detection or Receiver if everything once motion is enemy is enemy sensor is sensor is tripped in tripped in auto- - mode mode auto B2 B2 Failure of Failure of Failure of Failure of Enemy not Enemy not Observation Observation High High Enemy Motion detected, Enemy Motion detected, Detection Detection Sensors Sensors user at user at harms way harms way C1 Gun shoots Gun shoots TIP122 User harm Observation High Friendly can C1 TIP122 User harm Observation High Friendly can unpredictably unpredictably failure failure get shot get shot even if IR even if IR MCU failure MCU failure remote remote works works D2 Unpredictable Unpredictable Failure of Gun can Observation High D2 Failure of Gun can Observation High motion of gun motion of gun GAL GAL move to move to friendly and friendly and shoot shoot

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

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