Team 8:Recon Robot Safety and Reliability Analysis Abhinav Valluru (presenter) Vinit bhamburdekar Arjun Bajaj Aabhas Sharma

Key Concerns Reliability: – Electronics for power supplies – Motor control – Microcontroller,GPS and wireless transciever Safety: – Batteries – Burns – Unexpected behavior

Part failure risk Heat – TB6612FNG H bridge – D24V6ALV step-down voltage converter Complexity – PIC 32MX360F512L microcontroller – RN-131 G wireless transceiver

FMECA Analysis: Major injuries predicted – Most severe: burn injuries Criticality Levels – Low: nuisance failure – Elevated: risk of additional part damage – High: definite part damage – “+I” Suffix: Chance of personal injury

FMECA : Major concerns Failure modePossible causesFailure effect Detection method Criticality 5V short circuit Damaged MOSFET, Shorted capacitors Excessive current and heat build-up, possible destruction Observation; heat and smoke buildup. Unpredictable/no behavior High + I 3.3 V short circuit Damaged MOSFET, Shorted capacitors Excessive current and heat build-up, possible destruction Observation; heat and smoke buildup. Unpredictable/no behavior High + I Motors stuck at Vcc PWM failure, H-bridge failure Motor(s) at full speed, excessive heating in motors Recon robot can’t maneuver around the obstacles properly Elevated + I Micro > MIPS Core clock fault, faulty power supply, fighting on output pins Heat buildup, decreased part lifetime, glitching in other parts Observation: heat and smell. Potential glitching in motor control Elevated + I

Steps to improve reliability Minimize design weight – Less current draw from motors, low power dissipation – Longer battery life Over-designing of power supplies – Exceed expected power & peak current ratings (20% or higher) – Lowest available temperature coefficients(C/W)

Questions ?