1. Safety and Reliability
Seraj Dosenbach
Greg Lammers
Beau Morrison
Ananya Panja

2. Critical Safety & Reliability Issues
Safety Concerns
Sonar Sensor Failure
Motor Control Failure
Reliability Concerns
Servo Driver Failure
Switching Regulator Failures

3. Most Likely to Fail Components
HCS9S12A256 Microcontroller
Complexity
VNH3SP30 H-Bridge
High Current
LT1374 Switching Regulator
High Power Supply
AP1509 Switching Regulator

4. FMECA Analysis Table Failure No. Failure Mode Possible Causes
Failure Effects
Method of Detection
Criticality A5
Sonar 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 A7
Gripper/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 B1
Motor 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. C4
5V Output = 0V
Failure 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

5. Possible Improvements
Breakaway E-Switch
Acts as a “leash”
Add Stationary Logic Hub
Place microcontroller at stationary location

6. Questions?