SAFETY AND RELIABILITYSeraj DosenbachGreg LammersBeau MorrisonAnanya Panja

Critical Safety & Reliability Issues

Safety Concerns Sonar Sensor Failure Motor Control Failure

Reliability Concerns Servo Driver Failure Switching Regulator

Failures

Most Likely to Fail Components HCS9S12A256

Microcontroller Complexity

VNH3SP30 H-Bridge High Current

LT1374 Switching Regulator High Power Supply

AP1509 Switching Regulator High Power Supply

FMECA Analysis TableFailure No. Failure Mode Possible Causes Failure Effects

Method of Detection Criticality

A5Sonar Sensor Failure

Failure of HCS9S12 pins 51-53, external sonar sensors

Inability to detect unidentified objects. Possibility to damage itself or nearby objects/people at high speeds. Observation High

A7Gripper/Neck Failure

Failure of external servos, HCS9S12 pins 78,79,1,2

Unpredictable movement of neck that could cause servos to over extend and burn out

Observation, limp neck Medium

B1Motor Driver Failure

Shorts of resistors R9, R10, R1, R11, R12, R13, R14, R2, R3, R4, R5, R6, R7

Unpredictable breaking/reversal of left/right motors, but most likely motors will not function. Observation High

C4 5V Output = 0VFailure of C8, LT1374, C13, U2, U5, U4, C6

Device does not function, too much current being drawn through areas that could heat up and potentially burn out Observation Medium

Possible Improvements Breakaway E-Switch

Acts as a “leash”

Add Stationary Logic Hub Place

microcontroller at stationary location

Questions?