Transcript SWISH SLEEVE Safety and Reliability Analysis

SWISH SLEEVE
Safety and Reliability Analysis
Stephen MacNeil, Michael Kobit,
Sriharsh Achukola, Augustus Hong
Project Overview
We would like to design and implement a shooting
sleeve made from compression material that
basketball players or pitchers could wear to track
their motion, without the use of cameras. This
prevents current occlusion issues inherent in
optical motion capture. The sleeve can be
extended to other sports as well and beyond the
scope of this class could be extended to an entire
suit which could monitor sports performance in
athletes.
Criticality
High Criticality
Failure that could potentially lead to injury to the user
Medium Criticality
Failure that could render components permanently nonfunctional.
Low Criticality
Failure that affects performance or creates disfunctionality to
the device.
Critical Component
Microcontroller – PIC32MX795F512H
Synchronous Buck Regulator – LM20143
Battery Monitoring – DS2781
PIC32MX795F512H-Microcontroller
Failure No.
Failure
Mode
Possible
Causes
Failure
Effects
Method of
Detection
Criticality
A1
UART
failure
Fault with the
pins
Unable to
communicate
with atom
board
Observation
Medium
A2
TIMER
failure
Failure to
initialize or set
proper length
delays
Unable to
maintain
periodic data
extraction and
transmit
Observation
Low
A3
I2C failure
Issue with SDA
and SCL pins
Unable to read
the IMU data.
Observation
Low
A4
Reset failure Fault with
pushbutton
Micro is unable Observation
to reset or
consistently to
reset
Medium
Remarks
PIC32MX795F512H-Microcontroller
Parameter name
Description
Value
Comments regarding
choice of parameter value,
especially if you had to
make assumptions.
C1
Die complexity
0.56
32 – bit processor
ΠT
Temperature coeff.
0.71
Assume linear 50 degree C
C2
Package Failure Rate
0.025
64 pin SMT
ΠE
Environmental Factor
4
Ground, Mobile
ΠQ
Quality Factor
10
Commercially manufactured
component
ΠL
Learning Factor
1
≥ 2 years in production
λP
Part Failure Rate
4.97
Failures/10^6 hours
Entire design(MTTF):
201207 Hours = 22 Years
LM20143 – Synchronous Buck Regulator
Failure No.
Failure
Mode
Possible
Causes
Failure
Effects
Method of
Detection
Criticality
B1
Vout < 3.3V
LM20143 is
burned out or
Caps burned
out
IMU, XBEE,
Micro and
LCD will not
function
Observation Medium
B2
Vout > 3.3V
LM20143 is
shorted or
Caps/resistor
shorted
IMU, MICRO,
LCD and
XBEE might
be damaged
Observation Medium
B3
Vout < 3.3V
or Vout >
3.3V
Damaged
during
sodering
unpredictable
Observation Medium
Remarks
LM20143 – Synchronous Buck Regulator
Parameter name
Description
Value
Comments regarding
choice of parameter
value, especially if you
had to make
assumptions.
C1
Die complexity
0.010
1 to 100 MOS pins
ΠT
Temperature coeff.
0.71
Assumer linear 50 degree C
C2
Package Failure Rate
0.0056
16 pin SMT
ΠE
Environmental Factor
4.0
Ground, Mobile
ΠQ
Quality Factor
10
Commercially manufactured
component
ΠL
Learning Factor
1
≥ 2 years in production
λP
Part Failure Rate
0.295
Failures/10^6 hours
Entire design(MTTF):
3389830 Hours = 386 Years
DS2781 – Battery Monitoring
Failure No.
Failure Mode
C1
Possible
Causes
Failure
Effects
Method of
Detection
Criticality
Remarks
Output
DS2781
continuously 0 burned out,
zenor diode
shorted
Incorrect
battery
readings
Reading is 0
even after a
full charge
Medium
See *
C2
Output
DS2781
continuously 1 shorted, or
some other
resistor
shorted
Incorrect
battery
readings
Reading is 1
after long time
of use
Medium
See *
C3
Battery
monitoring
values
incorrect
Incorrect
battery
readings
Reading is low Medium
after full
charge, or
high after long
time of use
See *
DS2781
burned out,
circuit not
implemented
correctly
*Incorrect Battery readings could lead to irregular charging cycles,
and therefore decreasing the battery’s lifetime
DS2781 – Battery Monitoring
Parameter name
Description
Value
Comments regarding
choice of parameter
value, especially if you
had to make
assumptions.
C1
Die complexity
0.010
1 to 100 MOS pins
ΠT
Temperature coeff.
0.71
Assumer linear 50 degree C
C2
Package Failure Rate
0.0026
8 pins SMT hermetic
ΠE
Environmental Factor
4.0
Ground, Mobile
ΠQ
Quality Factor
10
Commercially manufactured
ΠL
Learning Factor
1
≥ 2 years in production
λP
Part Failure Rate
0.175
Failures/10^6 hours
Entire design(MTTF):
5714285 Hours = 651 Years
Questions?