Single-Axis Tilt-Sensor Systems

Harry M.M. Kerkvliet and Gerard C.M. Meijer

Soz 2004.

Tilt sensors with electronic readout

• Improved accuracy • Data storage• Applicable in control loops

System set-up

C

Interface

Tilt-sensing element

Resistive element

Capacitive element

Resistive element

• Null impedance 1000 • Null repeatability 3 arcsec• Operating temperature –20 0C to + 50 0C

Connection with interface

E

F

B

OUT UTI

D

C

A

sensor

R

R R1

R1

1 c y c l e

TA B / 3 2 T C D T o f f

Experimental results

• Resolution: 1 arcsec for measurement time of 1 s

-2.E-03

-1.E-03

0.E+00

1.E-03

2.E-03

-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60TILT (arcsec)

Mr

Capacitive elements

Advantages- non-invasive- low-cost

Interface

1 c y c l e

T C l e f t T C r i g h t T C o f f

D

C

OUT UTI

B

Crigh

t

Cleft

Coff

A

F

E

Experimental results for the capacitive sensor

0.009

0.010

0.011

0.012

0.013

-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60

TILT (arcsec)

(Mc - 1)

• Resolution: 4 arcsec for measurement time of 1 s

Conclusions

• Two types of electronic tilt sensors have been implemented, using– resistive electrolytic elements– capacitive elements

• The resistive elements show a good linearity and a high resolution

• The capacitive sensors have the advantage of non-invasive electrodes, but the electrode structure should be improved

Questions ?

Soz 2004.