TECHNOLOGY DIGEST - Draper Laboratory

Finally, Figures 14 and 15 show long-term (30-day) SF
and bias stability measured on two SOA-SINS units (S/Ns
028 and 063). The better of the two units demonstrates a
1σ SF stability of 0.73 ppm and a 1σ bias stability of
approximately 2 µg over 30 days.
ppm
µg
12
S/N 028 Avg. SF = 247.4 Hz/g
S/N 063 Avg. SF = 258.8 Hz/g
S/N 028 SF (1σ) = 0.73 ppm
S/N 063 SF (1σ) = 1.22 ppm
Days
Figure 14. Long-term SOA-SINS SF stability.
Figure 15. Long-term SOA-SINS bias stability.
The Silicon Oscillating Accelerometer
SF 063
SF 028
Linear (SF 063)
Linear (SF 028)
2.0
1.5
1.0
0.5
0.0
-0.5
dSF/SF = -0.102 ppm/day
-1.0
-1.5
dSF/SF = -0.011 ppm/day
-2.0
0 5 10 15 20 25 30 35 40
S/N 028 Bias (1σ) = 2.04 µg
S/N 063 Bias (1σ) = 2.68 µg
Days
Bias 063
Bias 028
Linear (Bias 063)
Linear (Bias 028)
5.0
4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
dBias = 0.220 µg/day
-3.0
-4.0
dBias = 0.064 µg/day
-5.0
0 5 10 15 20 25 30 35 40
CONCLUSIONS
Draper Laboratory is currently developing the SOA, a
MEMS-based inertial-grade sensor. Performance data
acquired to date meet requirements for missile guidance
missions and for high-performance navigation applications
such as the SLBM SINS navigation systems.
The missile and SSBN applications have significantly different
environmental, acceleration dynamic range, and
resolution requirements that are best satisfied by optimizing
the SOA geometry for each application. The design
flexibility and wafer-scale fabrication methods of the silicon
MEMS process enable manufacturing both instrument
designs with essentially zero incremental cost associated
with the additional instrument assembly line. That is, both
versions of the SOA share a common sensor package, electronics
architecture, main housing, and instrument
assembly process.
The MEMS technology is low cost and offers a rapidly
expanding commercial business base to leverage and sustain
accelerometer production and deployment in
next-generation strategic system applications. Integration of
the SOA with mixed-signal, application-specific integrated
circuit (ASIC) electronics offers the promise of a low-cost,
small-size, low-power, and high-reliability strategic-grade
instrument.
REFERENCES
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McGraw Hill, 1975.
[4] Nayfeh, Mook, Nonlinear Oscillations, Wiley & Sons, New York,
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